NETWORK AND ITS COMPNENTS

Dr. Usha Munshi
Chief Librarian
Indian Statistical Institute
Calcutta
E-mail: umunshi@isical.ac.in, umunshi@gmail.com

NETWORK AND ITS COMPNENTS


Introduction

We are breathing in the computer age and gradually computer has become an integral part of our life. Computer is an indispensable and multipurpose tool performing multifaceted functions in multivariate environments. To make things more simpler, computer is touching every sphere of our life and has become a dire necessity be it in business, education, medicine and health care, science, engineering, manufacturing, legal practices, law enforcement, defense, government , at home, etc. Communication is another area which computers have made much easier and cheaper too. Internet – the mother of all networks which is a world wide network and connects people all over the globe and facilitates the global access to information that is available in the cyberspace and also that one wishes to send and share with other on the network.

The field of computer networking and today's Internet trace their beginnings back to the early 1960s, a time at which, the telephone network was the world's dominant communication network. The initial ARPAnet was a single, closed network. In order to communicate with an ARPAnet host, one had to actually be attached to another ARPAnet IMP (Internet Messaging Proggram). In the early to mid 1970's, additional packet-switching networks besides ARPAnet came into being; ALOHAnet, a satellite network linking together various universities. The number of networks was beginning to grow. In 1973, Robert Metcalfe's PhD thesis laid out the principle of Ethernet, which would later lead to a huge growth in so-called Local Area Networks (LANs) that operated over a small distance based on the Ethernet protocol.

3.0. Definition of A Network

Making devices to talk to each other for communication purposes is nothing new Early forays into telephony such as telegraph & telephone has since evolved into more complicated devices and now a computer can be networked to the Internet; a PC or to a home stereo for same purposes. Taking the case of early 1960s, individual computers – were physically shared and hence sharing of data & information was not easy.

Due to this impractical approach the seed of the need germinated by way of connecting computers & computer network was born. These Networks provided the basis for early ARPANET, the forerunner of the modern Internet. On June 3, 1968, a project proposal christened “ Resource Sharing & Computer Networks” submitted by the Advanced Research Projects Agency (ARPA), with an aim of not only to allow boosting sharing of their data, but also further their research activities in wide variety of military & scientific fields After being tested in 4 locations; the network spread. New protocols have since been created that evolved in today’s World Wide Network. The then new communication protocol –Packet Switching facilitated several applications, such as secure voice messaging in military channels. These new circuits provided basis for the communication technologies of the rest of 20th century. Their further development and fine –tuning were applied to Computer Networks. During 1977, early PC based LANs were spreading, initially restricted to academics and hobbyists, but eventually, found their way into the workplace & homes. LAN variants developed (MANs, WANs, etc) in academics sector. The corporate world responded quickly and the landscape of how people conduct business altered This was primarily due to widespread use of computers, and speed and ease of using them for communications and data transfer. The past few years have seen a remarkable growth in the global networking infrastructure. The Internet has grown from a research curiosity to something we all take for granted, beginning to become as essential as the ubiquitous telephone and utility networks. It has been able to withstand rapid growth fairly well and its core protocols have been robust enough to accommodate applications that were unforeseen by the original Internet designers, such as the amazing success story that is the World Wide Web.
3.1. What is a Network?
Computer networking is the scientific and engineering discipline concerned with communication between computer systems. Such communicating computer systems constitute a computer network and these networks generally involve at least two devices capable of being networked with at least one usually being a computer. The devices can be separated by a few meters (e.g. via Bluetooth) or thousands of kilometers (e.g. via the Internet). Experts in the field of networking debate whether two computers that are connected together using some form of communications medium constitute a network. Therefore, some sources will state that a network requires three connected computers.,

A network or communications networks, is a system of interconnected computers, telephones, or other communications devices that can communicate with one another and share applications and data. It is the tying together of so many communications devices in so many ways, that is changing the world we live in.







Fig1: A View of Computers Connected in a
Network Environment


Alternatively you could also say that - A computer network is an interconnection of several computers which communicate with one another to share records, files and / or peripheral devices. The users can select services required and communicate with computer as a local user


In more simpler terms, one could say in three distinct parts: that A Computer Network is:
(i) A group of two or more computers connected together
(ii) With the ability to communicate with each other
(iii) For sharing information, applications or resources
Groth[1] states that "the term network describes two or more connected computers"

According to Federal Standard 1037C[2] a computer network is "A network of data processing nodes that are interconnected for the purpose of data communication", the term "network" being defined in the same document as "An interconnection of three or more communicating entities" While a communications network in which the end instruments are computers.

Here, let us also understand the two main gadgets associated with it that is:
1. Computer System?
2. Networking

Computer System: A complete, working computer includes not only the computer, but also any software and peripheral devices that are necessary to make the computer function. Every computer system, for example, requires an operating system. Computers on a network are sometimes called nodes, while Computers and devices that allocate resources for a network are called servers. Networking : It refers to: hardware and software, used to connect computers, allowing them to communicate with one another. For instance cabling, Network Operating systems, and a variety of network components flesh out a network that can include a wide variety of computers and devices

In general we can say that a computer network is any set of computers or devices connected to each other. Examples of networks are the Internet, a wide area network that is the largest to ever exist, or a small home local area network (LAN) with two computers connected with standard networking cables connecting to a network interface card in each computer.

Thus a network is an interconnected system of nodes, or objects. In computer terminology, networks usually refer to either the electric distribution systems some large IT providers manage, or systems of interconnected computers. The largest of these computer networks is the Internet. Other computer networks may be as small as a single personal computer connected to the Internet via a router, or as large as a university campus with several thousand machines communicating via a central server. Other common networks include small home LAN's, company intranets, and VPN (Virtual Private Network )virtual networks.
































Fig 2: A Sample Network Diagram

(Source :http://upload.wikimedia.org/wikipedia/en/1/12/Sample-network-diagram.png)

4.0.Importance of Networking

Why is networking important? How is networking facilitating us and what are we able to do with this facility, these are some issues that we will grapple with in this course, as they form the basis of the networking in global context.

The early goal was to make computers talk to one another. But today millions of computers are connected with some means of communication. Sharing of resources and communication are two main reasons (amongst many) that makes a computer network very important in this Internet Society. There are numerous applications (email, entertainment, commerce…) that are becoming increasingly dependent. Networks have proliferated into many walks of life. The ubiquitous computing and Internet keeps people connected (no matter what and where they are), such as with capable cellular phones. Every day functions are getting mutated and improved (especially in the corporate world) , thereby allowing data to flow at (almost) just-instant speed .

Computer networks, and the technologies needed to connect and communicate through and between them, continue to drive computer hardware, software, and peripherals industries. This expansion is mirrored by growth in the numbers and types of users of networks from the researcher to the home user.
Today, computer networks are a requirement of modern communication. The scope of communication has increased significantly in the past decade and this boom in communications might not have been possible without the advancements in computer networks.
A glimpse in to the future may predict a way change in the way we conceived the thoughts of these networks would aim at. :While initial aim was to see everyone on the planet – “Wired” It seems to be happening other way round now: Technological advances are advancing towards “wireless Technology. Coming up are cable free alternative to Wired Networks. Not long ago from now, it is predicted that
by 2009 wearable computers which will replace the Personal Digital Assistant or PDA will be fully integrated in the workplace with ability to connect to both wired and wireless networks. Other emerging technologies include - Smart appliances that are products which have enhanced the capabilities and facilitated further access to internet. Secondly, the fully automated home that have appliances for heating, cooling, entertainment, etc connected via a LAN.
The following advantages are particularly true for LANs, although, they apply to MANs and WANs as well.

 Sharing of peripheral devices
 Sharing of programs and data
 Better communications
 Security of information
 Access to databasesThey act as Discourse Facilitators for carrying out conversation/discussion
 Facilitate Resource Location for Research and other academic activities
 Support Resource Creation that is they help us in e-Publishing (self publishing, web publishing : scholarly contents, business stuff, etc.
 Computer Network also Facilitates
 Cooperation
 Coordination
 Collaboration
 Promotes Concept of : Global Reach
 No Geographical Barriers
 Access to All You can improve efficiency by sharing information such as common files, databases and business application software over a computer network.You can improve communication by connecting your computers and working on standardised systems.Network facilitates among other things:
 Directory service that provides map of the network so that resources can be accessed without knowing their exact physical location
 Convergence – The focus here is on technological convergence where multiple products come together to form one product, with the advantages of each initial component.
 Convergence in the media has led to the removal of entry barriers across the IT, telecoms, media and consumer electronics industries, creating one large "converged" industry”. For example Computer Telephony Integration (CTI) is the merging of traditional telephony with computer systems to provide such services as call routing, reporting, and integration with business applications
 Call Center
 IP-PBX IP-based or IP-enabled
 IVR Integrated Voice Response
 VoIP Voice over Internet Protocol (Voice Over IP or VoIP) refers to technologies that have been developed to transfer voice in digital format using the Internet Protocol.
 Messaging – these are processes associated with any electronic data that is created on, stored on or transferred over a network
Networks and their Classification

Networks can be classified on the basis of various features and functionalities and goodies. Broadly speaking we can consider their classification pattern on the following features and functionalities:

5.1. Classification Based on Features & Functionalities

5.1.1. By Network Layer
Computer networks may be classified according to the network layer at which they operate according to some basic reference models that are considered to be standards in the industry such as the seven layer OSI reference model and the five layer TCP/IP model.

5.1.2. By Scale
Computer networks may be classified according to the scale or extent of reach of the network, for example as a Personal area network (PAN), Local area network (LAN), Campus area network (CAN), Metropolitan area network (MAN), or Wide area network (WAN).


5.1.3. By Connection Method
Computer networks may be classified according to the technology that is used to connect the individual devices in the network such as Power line communication, Ethernet, or Wireless LAN.

5.1.4. By Functional Relationship
Computer networks may be classified according to the functional relationships which exist between the elements of the network, for example Active Networking, Client-server and Peer-to-peer (workgroup) architectures. Also, computer networks are used to send data from one to another by the hardrive

5.1.5. By Network Topology
Computer networks may be classified according to the network topology upon which the network is based, such as Bus network, Star network, Ring network, Mesh network, Star-bus network, Tree or Hierarchical topology network, etc. Topology can be arranged in a Geometric Arragement.

5.1.6. By Services Provided
Computer networks may be classified according to the services which they provide, such as Storage area networks, Server farms, Process control networks, Value-added network, SOHO network ("occasionally used to refer to a local area network as used in a Small office/home office business), Wireless community network, XML appliance, , etc.

5.1.7.By Protocol
Computer networks may be classified according to the communications protocol that is being used on the network.

6.0 Types of Networks

There are many types of computer networks, which differentiate one type from another based on primarily on geographic area they cover. Types can also be differentiated on the basis of the characteristics they depict.

As your activities develops, you might wish to consider other networks such as wide area networks (WANs), virtual private networks (VPNs), intranets and extranets. These networks each offer different business benefits, such as linking together systems in different offices, allowing remote workers to access your office systems securely, or providing up-to-date information for your staff and business partners . WANs are used by companies with offices at different locations. The WAN connects different local area networks together, into a more complex network. You will need to use client/server networks, which are based around central server computers, so that you can connect the various servers over a telecommunications network. WANs use cables/lines that are leased from a telecoms company

A VPN allows the user to connect across the Internet to the business' private network. It creates a secure link between the remote worker's computer and the central system. A VPN can be cheaper to use than leased lines or domestic-type broadband connections
Many businesses now build internal networks. These intranets store information on a central system at a private Internet address. Employees can access business information by connecting to the Internet, making it particularly useful for employees who travel or work from home.

Businesses can also open up their intranets to partners, such as suppliers and customers, typically with a password. This is an extranet. For example, a business can let clients track the progress of their orders, and the payment of suppliers online can be linked directly to the business accounts system.

Many types of computer networks which differentiate from one type to another [based on primarily on geographic area] For instance:
 LAN
 WAN
 CAN
 MAN
 HAN
 Others

The most common types of computer networks. are described below.

6.1.Local Area Network (LAN):
A network that is limited to a relatively small spatial area such as a room, a single building, a ship, or an aircraft. Local area networks are sometimes called a single location network.

For administrative purposes, large LANs are generally divided into smaller logical segments called workgroups. A workgroup is a group of computers that share a common set of resources within a LAN.

In general we can say that LANs are •computer networks that spans a relatively small area. The computers are geographically closely located in relation to each other. Most LANs are confined to a single building or group of buildings and • connect workstations and personal computers Each node or individual computer in a LAN has its own CPU with which it executes programs, but it also is able to access data and devices anywhere on the LAN This means that many users can share expensive devices, such as laser printers, as well as data. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions
•A local area network (LAN) is a computer network covering a small geographic area, like a home, office, or group of buildings.[3] Current LANs are most likely to be based on switched IEEE 802.3 Ethernet technology, running at 10, 100 or 1,000 Mbit/s, or on IEEE 802.11 Wi-Fi technology. Each node or computer in the LAN has its own computing power but it can also access other devices on the LAN subject to the permissions it has been allowed. These could include data, processing power, and the ability to communicate or chat with other users in the network.[2]
Based on the above definition, we can infer there are many different types of LANs, Ethernets being the most common for PCs.. Most Apple Macintosh networks are based on Apple's - AppleTalk network system, which is built into Macintosh computers
LANs are capable of transmitting data at very fast rates, much faster than data can be transmitted over a telephone line; but the distances are limited, and there is also a limit on the number of computers that can be attached to a single LAN
The defining characteristics of LANs, in contrast to WANs (wide area networks), are: their much higher data rates, smaller geographic range, and that they do not require leased telecommunication lines.

Since LANs have become an important component of Libraries and information Centres, due to the astonishing developments in the Information Technology. Therefore it may be relevant to focus on some more details about LAN.

The following characteristics differentiate one LAN from another
Topology : The geometric arrangement of devices on the network. For example, devices can be arranged in a ring or in a straight line.

Protocols : The rules and encoding specifications for sending data. The protocols also determine whether the network uses a peer-to-peer or client/server architecture.
Media : Devices can be connected by twisted-pair wire, coaxial cables, or fiber optic cables.
However, some networks do without connecting media altogether, communicating instead via radio waves
Local area networks are made up of several standard components that are discussed in another unit.







Fig 3: Local Area Network Scheme

(Source: http://upload.wikimedia.org/wikipedia/commons/7/7e/Schema_di_una_LAN.png)

6.2.Wide Area Networks (WANs)
One LAN can be connected to other LANs over any distance via telephone lines and radio waves. A system of LANs connected in this way is called a wide-area network (WAN) The computers are farther apart and are connected by telephone lines or radio waves.
Therefore, a computer network that spans a relatively large geographical area. Can be termed as WAN. Typically, a WAN consists of two or more local-area networks (LANs)Computers connected to a wide-area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites

Alternatively, a WAN is a data communications network that covers a relatively broad geographic area and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer. The largest WAN in existence is the InternetThere are broadly two types of WANs:
Centralized: A centralized WAN consists of a central computer that is connected to dumb terminals and / or other types of terminal devices.

Distributed: A distributed WAN consists of two or more computers in different locations and may also include connections to dumb terminals and other types of terminal devices.
6.3 Campus Area Networks (CANs)
The computers are within a limited geographic area, such as a campus or military base. An interconnection of local-area networks within a limited geographical space.
a network can be treated as a CAN that connects two or more LANs but that is limited to a specific (possibly private) geographical area such as a college campus, industrial complex. A CAN is thus generally limited to an area that is smaller than a Metropolitan Area Network
Controller Area Network.
This type of CAN is basically a serial bus network of micro controllers that connects devices, sensors and actuators in a system or sub-system for real-time control applicationsfirst developed for use in automobiles. However their applications have moved beyond automobiles, and now controller area networks can be used as an embedded communication system for micro controllers as well as an open communication system for intelligent devices.
•6.4.Metropolitan Area Network (MAN)
A metropolitan area network (MAN) is a communications network covering a geographic area, the size of a city or suburb. A network that connects two or more LANs or CANs together but does not extend beyond the boundaries of the immediate town, city, or metropolitan area. Multiple routers, switches & hubs are connected to create a MAN.
Broadly we can say that MAN is a data network designed for a town or city. In terms of geographic breadth, MANs are larger than local-area networks (LANs), but smaller than wide-area networks (WANs)MANs are usually characterized by very high-speed connections using fiber optical cable or other digital media. The purpose of a MAN is often to avoid long-distance telephone charges. Cellular phone systems are often MANs.


6.5. Home Area Networks (HAN)
HAN is a network contained within a user's home that connects a person's digital devices, from multiple computers and their peripheral devices to telephones, VCRs, televisions, video games, home security systems, "smart" appliances, fax machines and other digital devices that are wired into the network
In simple terms - A network contained within a user's home that connects a person's digital devices is a HAN.
•6.Internetwork

Internetwork refers to a scenario when two or more networks or network segments are connected using devices that operate at layer 3 that is the 'network' layer of the Open Systems Interconnection Basic Reference Model (OSI Basic Reference Model for short), such as a router.

Again Internetwork may also be defined as : Any interconnection among or between public, private, commercial, industrial, or governmental networks .

6.Intranet:
A network or internetwork that is limited in scope to a single organization or entity and which uses the TCP/IP protocol suite. . Intranets may also be categorized as a LAN, CAN, MAN, WAN, or other type of network.
68. Extranet:
A network or internetwork that is limited in scope to a single organization or entity but which also has limited connections to the networks of one or more other usually, but not necessarily, trusted organizations or entities

Technically, an extranet may also be categorized as a CAN, MAN, WAN, or other type of network, although, by definition, an extranet cannot consist of a single LAN, because an extranet must have at least one connection with an outside network.

Intranets and extranets may or may not have connections to the Internet. If connected to the Internet, the intranet or extranet is normally protected from being accessed from the Internet without proper authorization. The Internet itself is not considered to be a part of the intranet or extranet, although the Internet may serve as a portal for access to portions of an extranet.

7.0. Network Topology

The classification of computers in an network environment can be based on Ways of networking. Computers can be connected to a network in a number of ways. The most commonly used are standard wireless (wi-fi) networks using something like a router that has wireless functions built in, normally in 802.11b/g or using cables such as CAT5E or fiber optic. This will create a LAN on all computer system using the network.

Computer Network types Can also be differentiated on the basis of the characteristics.
Broadly these could be classified under this segment on the following basis:

 Topology
 Protocol
 Architecture

7.1. Topology
The Topology refers to the shape of a network, or the network's layout. How different nodes in a network are connected to each other & how they communicate are determined by the network's topology.

Therefore, Network topology is the study of the arrangement or mapping of the elements such as links, nodes, etc. of a network, especially the physical that is real and logical that is virtual interconnections between nodes














:
Fig 4: Schematic Representation of Different Network Topologies.
Source : http://en.wikipedia.org/wiki/Network_topology

Any particular network topology is determined only by the graphical mapping of the configuration of physical and/or logical connections between nodes - Network Topology is, therefore, technically a part of graph theory. Distances between nodes, physical interconnections, transmission rates, and/or signal types may differ in two networks and yet their topologies may be identical.

7.1.1. Types of Topologies
The arrangement or mapping of the elements of a network gives rise to certain basic topologies which may then be combined to form more complex topologies commonly refered to as hybrid topologies. The most common of these basic types of topologies are Bus ,star , Ring , Mesh , Tree .
7.1.2. Common Network Topologies
The Common topologies include :
 Mesh Topology
 Star Topology
 Bus Topology
 Ring Topology
 Tree Topology
Here shall be describing these common network topologies briefly.

7.1.2..1.Mesh Topology
•Devices are connected with many redundant interconnections between network nodesIn a true mesh topology every node has a connection to every other node in the network
Therefore a Mesh networking is a way to route data, voice and instructions between nodes. It allows for continuous connections and reconfiguration around broken or blocked paths by "hopping" from node to node until the destination is reached. A mesh network whose nodes are all connected to each other is a fully connected network.Mesh networks are self-healing: the network can still operate even when a node breaks down or a connection goes bad. As a result, a very reliable network is formed. This concept is applicable to wireless networks, wired networks, and software interaction.


Fig 5: Images Showing Mesh Network Layout




7.1.2.2. Star Topology

Here all devices are connected to a central hubnodes communicate across the network by passing data through the hub.
Star networks are one of the most common computer network topologies. In its simplest form, a star network consists of one central switch, hub or computer which acts as a router to transmit messages. If the central node is passive, the originating node must be able to tolerate the reception of an echo of its own transmission, delayed by the two-way transmission time (i.e. to and from the central node) plus any delay generated in the central node. An active star network has an active central node that usually has the means to prevent echo-related problems.
The star topology reduces the chance of network failure by connecting all of the systems to a central node. Strictly speaking only networks that use switches have a true star topology. If the network uses a hub, the network topology has the physical appearance of a star, but is actually a bus.
The advantages of this type of network lies in its good performance., easy to set up and to expand, and easy to detect faults. Besides any non-centralised failure will have very little effect on the network, whereas on a ring network it would all fail with one fault. While its drawbacks are being expensive to install, and in its extra hardware requirement. Moreover, if the host computer fails the entire system is affected.
7.1.2.3. Bus Topology

In this all devices are connected to a central cable, called the bus or backbone .
A bus network is a network architecture in which a set of clients are connected via a shared communications line, called a bus. Bus networks are the simplest way to connect multiple clients, but often have problems when two clients want to transmit at the same time on the same bus. A true bus network is passive – the computers on the bus simply listen for a signal; they are not responsible for moving the signal along. However, many active architectures can also be described as a "bus", as they provide the same logical functions as a passive bus; for example, switched Ethernet can still be regarded as a logical bus network, if not a physical one. With the dominance of switched Ethernet over passive Ethernet, passive bus networks are uncommon in wired networks. However, almost all current wireless networks can be viewed as examples of passive bus networks, with radio propagation serving as the shared passive medium..
easy to implement and extend Easy to implement and extend They requires less cable length than a star topology and are well suited for temporary or small networks not requiring high speeds
However, they have several drawbacks as well. For instance , difficulty in administering the /troubleshoot. If there is a problem with the cable, the entire network goes down. Hence maintenance costs may be higher in the long run. In terms of performance , as additional computers are added or on heavy traffic, it degrades. Proportionally. Besides low security, one virus threats for affecting the entire network and the like.

7.1.2.4. Ring Topology

Here all devices are connected to one another in the shape of a closed loop, so that each device is connected directly to two other devices, one on either side of it.
a ring network is a topology of computer networks where each node is connected to two other nodes, so as to create a ring.
The importance of this type of network lies in the fact that the data transmission is quick and relatively simple as packets travel in one direction only. It prevents network collisions because of the media access method or architecture required
Ring networks tend to be inefficient when compared to Star networks because data must travel through more number of points before reaching its destination. For example, if a given ring network has eight computers on it, to get from computer one to computer four, data must travel from computer one, through computers two and three, and to its destination at computer four. It could also go from computer one through eight, seven, six, and five until reaching four, but this method is slower because it travels through more computers. The other drawbacks of this type networks are that If any of the nodes fail then the ring is broken and data cannot be transmitted successfully..There is total dependence upon the one cable. As such in order for all computers to communicate with each other, all computers must be turned on. Besides to add a station you must shut down the network temporarily, . because all stations are wired together. 7.1.2.5. Tree Topology
Tree and hypertree networks are important special cases of star network topologies.
A Tree Network consists of star-configured nodes connected to switches/concentrators, each connected to a linear bus backbone. Each hub/concentrator rebroadcasts all transmissions received from any peripheral node to all peripheral nodes on the network, sometimes including the originating node. All peripheral nodes may thus communicate with all others by transmitting to, and receiving from, the central node only. The failure of a transmission line linking any peripheral node to the central node will result in the isolation of that peripheral node from all others, but the rest of the systems will be unaffected.
In simple terms we may say that it is a hybrid topology. Groups of star-configured networks are connected to a linear bus backbone.


Fig 6: Image Showing Tree Network Layout

7.2. Classification of Network Topologies
There are three basic categories of network topologies: This means that network topologies could fall under one of these categories.
 Physical topologies
 Signal topologies
 Logical topologies
It may be indicated here that the terms signal topology and logical topology are often used interchangeably even though there is a subtle difference between the two and the distinction is not often made between the two.7.2.1.Physical Topology
•Every LAN has a topology, or the way that the devices on a network are arranged and how they communicate with each other. The way that the workstations are connected to the network through the actual cables that transmit data that is the physical structure of the network -- is called the physical topology. Alternatively we can say that Physical Topology refers to the mapping of the nodes of a network and the physical connections between them – i.e., the layout of wiring, cables, the locations of nodes, and the interconnections between the nodes and the cabling or wiring system

7.2.2.Signal Topology
The mapping of the actual connections between the nodes of a network, as evidenced by the path that the signals take when propagating between the nodes.
The term 'signal topology' is often used synonymously with the term 'logical topology', however, , by definition, the term 'logical topology' refers to the apparent path that the data takes between nodes in a network while the term 'signal topology' generally refers to the actual path that the signals e.g., optical, electrical, electromagnetic, etc. take when propagating between nodes.


7.2.3.Logical Topology

Logical topology is the way that the signals act on the network media,.

Alternatively, the way that the data passes through the network from one device to the next without regard to the physical interconnection of the devices
Logical topologies are bound to the network protocols that direct how the data moves across a network. For instance: Ethernet protocol is a common logical bus topology protocol.; LocalTalk is a common logical bus or star topology protocol.. or IBM's Token Ring is a common logical ring topology protocol. A network's logical topology is not necessarily the same as its physical topology. For example, twisted pair Ethernet is a logical bus topology in a physical star topology layout, while IBM's Token Ring is a logical ring topology. It is physically set up in a star topology.

However there could be another group of topologies that is formed by combination of different type of topologies, hence form hybrid topologies.

7.2.4. Hybrid Network Topologies
The hybrid topology is a type of network topology that is composed of one or more interconnections of two or more networks that are based upon different physical topologies or a type of network topology that is composed of one or more interconnections of two or more networks that are based upon the same physical topology, but where the physical topology of the network resulting from such an interconnection does not meet the definition of the original physical topology of the interconnected networks. For example, the physical topology of a network that would result from an interconnection of two or more networks that are based upon the physical star topology might create a hybrid topology which resembles a mixture of the physical star and physical bus topologies or a mixture of the physical star and the physical tree topologies, depending upon how the individual networks are interconnected, while the physical topology of a network that would result from an interconnection of two or more networks that are based upon the physical distributed bus network retains the topology of a physical distributed bus network.
Examples could be : Star-Bus; Star-Wired Ring, etc.

7.3 Network Architecture and Services
Architecture basically is a design. The term architecture can refer to either hardware or software, or to a combination of hardware and software. The architecture of a system always defines its broad outlines, and may define precise mechanisms as well
•
There could be two types of mechanisms for network architecture :
(i) Open Architecture
(ii) Closed Architecture
Open Architecture : An open architecture allows the system to be connected easily to devices and programs made by other manufacturers Open architectures use off-the-shelf components and conform to approved standards
Closed ArchitectureA system with a closed architecture, on the other hand, is one whose design is proprietary, making it difficult to connect the system to other systems
The architectural principles that Robert Kahn articulated for creating a so-called "open network architecture" are the foundation, on which today's Internet is built (In electronic format: http://gaia.cs.uman.edu/kurose/introduction/history.htm) Broadly these principles are:
 Minimalism, Autonomy: This implies that a network should be able to operate on its own, with no internal changes required for it to be internetworked with other networks;
 Best Effort Service: Internetworked networks would provide best effort, end-to-end service. If, reliable communication was required, this could be accomplished by re-transmitting lost messages from the sending host;
 Stateless Routers: The routers in the internetworked networks would not maintain any per-flow state about any ongoing connection
 Decentralized Control: There would be no global control over the internet-worked networks.

7.3.1 Network Architecture

Networks can be broadly classified as using either a -
 Peer-to-peer or
 Client/server architecture

Both client/server and peer-to-peer architectures are widely used, and each has unique advantages and disadvantages.




7.3.1.1. Peer-to-Peer Architecture

Often referred to as peer-to-peer or P2P, it is the type of network in which each workstation has equivalent capabilities and responsibilities. Peer-to-peer networks are generally simpler, but usually do not offer the same performance under heavy loads.In simpler terms, Network architecture known as a peer-to-peer architecture because each node has equivalent responsibilitiesdiffers from client/server architectures, in which some computers are dedicated to serving the others
An important goal in peer-to-peer networks is that all clients provide resources, including bandwidth, storage space, and computing power. Thus, as nodes arrive and demand on the system increases, the total capacity of the system also increases.
The distributed nature of peer-to-peer networks also increases robustness in case of failures by replicating data over multiple peers, and -- in pure P2P systems -- by enabling peers to find the data without relying on a centralized index server. In the latter case, there is no single point of failure in the system.
7.3.1.2.Client/Server Architecture Network architecture in which each computer or process on the network is either a client or a server is called client/server architecture.
Servers are powerful computers or processes dedicated to managing disk drives (file servers), printers (print servers), or network traffic (network servers )
While clients are PCs or workstations on which users run applicationsClients rely on servers for resources, such as files, devices, & even processing power. Client-server architectures are sometimes called two-tier architectures
The plus points of this type of architecture are: that all the data are stored at the servers, so it has better security control ability. It is more flexible than P2P paradigm in the sense that if a server in client/server paradigm wants to update the data or other resources, it can do so without any hassel. . There are already a lot of matured technologies designed for client/server paradigm which ensures the security, user-friendly interface and ease of use. Besides any element of a C/S network can be easily upgraded.
The disadvantage in a client-server architecture is that, with a fixed set of servers, in which adding more clients could mean slower data transfer for all users. In client server paradigm , traffic congestion has always been a problem. And also it does not have as good robustness as P2P network has.



7.3.1.3.Other Network Architectures
It may be appropriate to throw light on some other emerging forms of network architectures. Here mention is being briefly made of Grid Computing and Internet2.

Grid Computing
An emerging computing model that distributes processing across a parallel infrastructure. Grid computing combines the processing power of multiple computers on a network to tackle a single problem at the same time.

Grid computing, in simple terms can be stated, to be a distributed computing taken to the next evolutionary level.

The goal of Grid Computing being to create the illusion of a simple yet large and powerful self-managing virtual computer out of a large collection of connected heterogeneous systems sharing various combinations of resources.
Standardization of communications between heterogeneous systems created the Internet explosion!. The emerging standardization for sharing resources, along with the availability of higher bandwidth, are driving a possibly equally large evolutionary step in grid computing
•Internet2 –
A consortium being led by 206 universities working in partnership with industry and government to develop and deploy advanced network applications and technologies, accelerating the creation of the next Internet.
•7.4. Network Protocol
Internetworking requires the joining of many communication facilities, which need to efficiently communicate. These communications are prepared for transmission by using standard conventions called communication protocols.
A protocol is a standard method for transmitting data through a network or an agreed-upon format for transmitting data between two devices
The protocol determines the following:
 the type of error checking to be used
 data compression method, if any
 how the sending device will indicate that it has finished sending a message
 how the receiving device will indicate that it has received a message
In simpler terms: the protocol defines a common set of rules and signals that computers on the network use to communicate
Protocols are arranged in layers; each layer contributes something in preparing the data for its journey. Each protocol layer involved in the encoding process provides a header which contains information which can be used in un-packaging the message when it is received.
There are many different specialized protocols to accommodate the many kinds of data that might be transmitted. Each of these protocols perform specific roles/functions. Some of the protocols are listed below and only a few important ones are being described briefly here.

DHCP, DNS , HTTP , IMAP , IP, IPv6 , MGCP/Megaco , MPLS / Frame Relay , POP3, PPP/SLIP, PPTP , RTP/RTSP, S/MIME, SCCP (Skinny), SIP, SMTP, SNMP, SSL/TLS, TCP/IP, VoIP, X.25.•DHCP : Dynamic Host Configuration Protocol (DHCP) is a TCP/IP protocol used to assign (IP) numbers to users on a network.
•
DNS : Domain Name System (DNS) translates domain names into Internet Protocol (IP) addresses. An IP address may have multiple domain names, which are intended to be text-based names that users will remember
•HTTP: (Hypertext Transfer Protocol) is a standard transmission method for text, graphic images, sound, video, and other multimedia files over the Internet
•IMAP: Internet Message Access Protocol (IMAP) is used to retrieve and read messages on a mail server. It has additional functionality that lets you manage messages while they are still located on the mail server•MGCP/Megaco : MEGACO/H.248 is the latest industry standard protocol for interfacing between hosts and call agents called Media Gateway Controllers (MGC's) and Media Gateways (MG's) – eg. an IP Telephone and the PSTN. Derived from MGCP•MGCP (VOiCOM)- As IP based telephony services began to gain some realism in the late 1990's, there was a clear need for 'gateway' control to interface to the many non-IP based networks & technologies (such as Residential Gateways, ATM, Access Gateways and the PSTN. MPLS / Frame Relay
•POP3 POP (Post Office Protocol), DMSP (Distributed Mail System Protocol), and IMAP (Internet Message Access Protocol). Of the three, POP is the oldest and consequently the best known •Local e-mail clients use the Post Office Protocol version 3 (POP3), an application-layer Internet standard protocol, to retrieve e-mail from a remote server over a TCP/IP connection. Nearly all subscribers to individual Internet service provider e-mail accounts access their e-mail with client software that uses POP3.
••PPP/SLIP : SLIP and PPP are two communication protocols which allow a computer connected to a server via a serial line (such as a modem) to become a actual node on the internet. This allows you to run network applications on your home computer directly. With a SLIP/PPP feed and the right software on your computer, you can not only run graphical web browsing software, you can also FTP files directly to your computer, store your mail on your computer, and many other functions.
•
While SLIP and PPP are largely similar, there are some key differences. PPP is a newer protocol, better designed, and more acceptable to the sort of people who like to standardize protocol specifications.
•
The most significant advantage PPP can offer is the automatic login and configuration negotiation. With these features, your PPP software only needs to know your login userid/password and the telephone number of your service provider. The software can then dial-up into your service provider and figure out everything else on its own. Once connected, PPP does NOT give you more of the internet than SLIP can.
•••PPTP Point-to-Point Tunneling Protocol (PPTP) provides corporations with the ability to conduct secure communications on Virtual Private Networks (VPNs) across dial-up, local area network, wide area network, or Internet connections•SMTP Simple Mail Transfer Protocol (SMTP) is the most widely used protocol for sending electronic mail (email) on the Internet. SMTP sends and receives email messages through the use of a Sender-SMTP process and a Receiver-SMTP process that perform email transmission and receipt services.
••SNMP The Simple Network Management Protocol (SNMP) serves as a network management tool that reports on the status of devices attached to a network. Usually these reports are limited to stating whether or not the devices are functioning properly•SSL/TLS The Secure Socket Layer, developed by Netscape, is a common protocol for providing secure transmission of messages on the Internet. It uses the program level between the HTTP and TCP layers. It is being replaced by the Transport Layer Security protocol, which ensures that a third party does not monitor communications between two sources
•TCP/IP The Transmission Control Protocol (TCP) and the Internet Protocol (IP) manages the flow of information over the Internet. TCP manages the assembly (and reassembly) of data into packets that can be easily transmitted over the Internet, while IP directs the packets to the their correct destination
VoIP Voice over Internet Protocol (Voice Over IP or VoIP) refers to the technologies that have been developed to transfer voice in digital format using the Internet Protocol•X.25 is an ITU-T standard protocol suite for wide area networks using the phone or ISDN system as the networking hardware. It defines standard physical layer, data link layer and network layers (layers 1 through 3) of the OSI model. Packet switched network was the common name given to the international collection of X.25 providers, typically the various national telephone companies
From a user's point of view, the important aspect about protocols is that your computer or device must support the right ones if you want to communicate with other computers
The protocol can be implemented either in hardware or in software7.5. Network Standards There is another set of parameters that adds to the characteristics of a robust, interoperable network - that is standard. The heterogeneity behviour of the systems over the network would lead to chaos, if there are no standards or standard practices followed by everyone participating in various activities over the network (particularly on the Internet) It is essential that some standard practices are followed in order to let things happen the way we want them to, thereby facilitating effective communication across the systems participating or required to participate for a particular transaction.
a definition or format that has been approved by a recognized standards organization or is accepted as a de facto standard by the industry

Standards exist for -
 Programming languagesOperating systemsData formats
 Communications protocols, and
 Electrical interfaces

Examples for different standards for Hardware, software and data transmission Include:
Hardware: IEEE is generally concerned with hardware, sets standards for most types of electrical interfaces. Most famous standard is probably RS-232C, which defines an interface for serial communication. This is the interface used by most modems, and a number of other devices, including display screens and mice.

Software: ANSI is primarily concerned with software. ANSI has defined standards for a number of programming languages
Data Transmission : ITU defines international standards, particularly communications protocols. It has defined a number of standards, that specify protocols for transmitting data over telephone lines. (including V.22, V.32, V.34 and V.42, )
From a user's standpoint, standards are extremely important in the computer industry because they allow the combination of products from different manufacturers to create a customized systemWithout standards, only hardware and software from the same company could be used together. In addition, standard user interfaces can make it much easier to learn how to use new applications
Most official computer standards are set by one of the following organizations:
 ANSI (American National Standards Institute)
 ITU (International Telecommunication Union)
 IEEE (Institute of Electrical and Electronic Engineers)
 ISO (International Standards Organization)
 VESA (Video Electronics Standards Association)
de facto standards
In addition to standards approved by organizations, there are also de facto standards. These are formats that have become standard simply because a large number of companies have agreed to use them. They have not been formally approved as standards, but they are standards nonetheless. PostScript is a good example of a de facto standard
7.5.1Standards & Protocols
There are a variety of standard protocols from which programmers can choose. Each has particular advantages and disadvantages. For example, some are simpler than others,
some are more reliable, and some are faster
One of the most popular protocols for LANs is called Ethernet, while another popular LAN protocol for PCs is the IBM token-ring network

7.5.1.1.Modern Network Hardware & Infrastructure Standards

Since the OSI Model is a reference rather than a standard, it leaves room for standards of many different designs and applications to be made in its image. The detailed description about this reference model has been given in another module.

Based upon OSI Layers one and two, these standards fill the gaps that exist in both technology and geographical distance allowing digital communication to : spread farther, carry information faster, and cost less.
7.5.1.1.1.Ethernet
Ethernet is a large, diverse family of frame-based computer networking technologies for local area networks (LANs). The name comes from the physical concept of the ether. It defines a number of wiring and signaling standards for the physical layer, through means of network access at the Media Access Control (MAC)/Data Link Layer, and a common addressing format.
Ethernet (standardized as IEEE 802.3) is used to link computers in both small residential and large commercial situations and is the most widely used Network Hardware Standard today.

Often delivers internet access from other longer range hardware standards to multiple computers within a home or workplace. Ethernet equipment is relatively small, affordable, and can carry data at high speeds. The original specification called for speeds of 10mbps. A newer version of Ethernet, called 100Base-T (or Fast Ethernet), supports data transfer rates of 100 Mbps. And the newest version, Gigabit Ethernet supports data rates of 1 gigabit (1,000 megabits) per second is one of the most widely implemented LAN standards, though has range limitations. Ethernet -most used standard for the transmission of digital information over short distances. A LAN may then be linked to other LANs via network infrastructure standards with long distance capabilities
7.5.1.1.2.Bluetooth

Bluetooth is an industrial specification for wireless personal area networks (PANs). Bluetooth provides a way to connect and exchange information between devices such as mobile phones, laptops, PCs, printers, digital cameras and video game consoles via a secure, globally unlicensed short-range radio frequency.
Bluetooth, (standardized as IEEE 802.15.1), is a short range wireless network standard originally developed by Ericsson Corporation. Designed to allow nodes to participate in a network using the lowest possible amount of power. Bluetooth's current maximum transmission rate is 2.1mbps. While this seems very low compared to much older Wi-Fi standards (such as 802.11b) Bluetooth is designed to fit a special section of the market, rather than to be a widespread, high-performance technology.

It is almost always used in a paired or "ad-hoc" type network. In an ad-hoc network, no router exists, but the nodes are simply responsible for negotiating communication among themselves automatically. A paired network is simply an ad-hoc network with only two nodes













It has several uses in devices using or requiring less bandwidth or are low power applications. Common Bluetooth devices and applications include mobile phone headsets, PC-to-organizer/PDA synchronization, and other situations in which small devices need low power, short range communication capability. Bluetooth is a staple feature on most of today's newest and smallest portable information and communication devices
As is evident from the above statements, Bluetooth is a radio standard and communications protocol primarily designed for low power consumption, with a short range based around low-cost transceiver microchips in each device.

Bluetooth lets these devices communicate with each other when they are in range. The devices use a radio communications system, so they do not have to be in line of sight of each other, and can even be in other rooms, so long as the received transmission is powerful enough.

Bluetooth technology will continue catering to the needs of very low power applications such as mice, keyboards and mono headsets, enabling devices to select the most appropriate physical radio for the application requirements, thereby offering the best of both worlds.7.5.1.1.3.WI-FI
Wi-Fi (IEEE 802.11x) is a standard developed to perform nearly the same role as Ethernet does in consumer settings, but without the wires. Taking to the air, Wi-Fi allows a node to lie anywhere within a 100 to 1000 ft range of a Wi-Fi enabled router and have a constant, secure connection to the Local Area Network.

Wi-Fi originated with speeds of just 11mbps in the form of IEEE 802.11b, but today can achieve speeds between 54mbps and 108mbps. Initially (Early 90s ) designed to provide wireless communication for cashier systems in retail locations and operated at speeds of 1 or 2mbps. Late 90s, the IEEE ratified the 802.11b specification, providing wireless Ethernet-like connectivity for nodes at speed steps between 1 and 11mbps. In 2003 and 2004 IEEE 802.11g, a newer standard based on the Wi-Fi specification, emerged. In 2005, an even newer standard began to emerge known as 802.11n
Let us see what are the uses of Wi Fi . It allows LANs to be deployed without cabling, typically reducing the costs of network deployment and expansion. Wi-Fi chipset pricing continues to come down, making Wi-Fi a very economical networking option and driving inclusion of Wi-Fi in an ever-widening array of devices. Wi-Fi is a global set of standards. Hence the same Wi-Fi client works in different countries around the world.
However there are some drawbacks also like power consumption is fairly high compared to some other standards, making battery life and heat a concern. Wi-Fi networks have limited range. Wi-Fi networks can be monitored and used to read and copy data transmitted over the network when no encryption such as VPN is used

PLANNING LIBRARY AUTOMATION

Understanding Planning

• Planning is a Process of Making Plan
• Plan is Statements of things to be done and the Sequence and Timing in which they should be done in order to achieve a given end.
• Planning Involves deciding on Aims and Objectives, Selecting the Correct Strategies and Programes to achieve the aims, determining and allocating the resources required and ensuring that plans are communicated to all concerned.
• Understanding Manpower, Material and Money available.


Understanding Library Automation

– Library Automation is use of machines in a Library for various activities.
• Collection: Compact Shelving, Electronic Mapping, Conveyor Belt System, Book Lift
• Security: Close Circuit Camera Device, Electronic Security Gate
• Users: Photocopier, Internet, Smart Card Library Ticket, Barcode Library Card
• Environment: Power Backup, Air Conditioning, Facilities
• Library Procedures: Computer Systems, CD Station Systems, LAN
• E-Resources: BookEye Machine for Digitisation, Microfilm Reader and Printer, Online E-References and DBs Access
• Multimedia Corner: Television, Audio System, Digital Audio and Video System.


Aims and Objectives of the Institute

Main Aims and Objectives of various types of institutes has to be understand. Academic Institute: Impart Courses at Bachelor and Master Levels. Research Institute: Perform research in the Area of specific fields. Schools : Conduct Classes from I to XII. Industries: Services, Development and Production of various products.

Library and Information Centre provide all information in fulfilling the Aims and Objectives of the Institute.

Depending up the institute the Aims and Objectives of the Institute must be studied and depending upon the information requirements for various on- going and future projects the following data has to be noted:

• Identification of Library Staff, Resources and Procedures
• Hardware and Software Requirements
• Project Costing: Identification of Resources, Vendors and Price
• Implementation Phases: Standalone to Multiuser and Modular to Integrated Approach
• Support and Upgradation
• Terms and Conditions
• Demonstration and Ordering : Demo Team and Checking of HW&SW
• Installation and Training
• Database Creation
• Running Library Automation Activities



Identification of Library staff

– Identifying Library Staff interested in Automation and providing Training in Basic Skills in Computer System and Software. Assigning Job profile for Library Automation according to their specialisation.


Identification of Library Resources

• Identifying Resources in order to process for Database Creation : Selecting first most circulated collection, second latest collection and than going retrospective from active collection to preserved Collection. Identifying Library Users: Selecting first staff than students and finally external members for Database Creation.

Identification of Library Procedures

– Identifying Library Procedures for automation from Acquisition to Cataloguing than to Circulation and Users’ Inquiry Search options, interlibrary and global access of resources.


Hardware and Software Requirements

– Computer Server Configuration (One)
– Computer Workstation Configuration (Five)
• Acquisition Workstation
• Cataloguing Workstation
• Periodical Workstation
• Circulation Workstation
• OPAC Workstation
– LAN Configuration: Switch/Hub, Connectors and Cabling
– Barcode Scanner (Two)
– Flatbed Scanner (One)
– Other Library Technology
– Softwares
• OS Software on Machine and LAN
• Library Automation Software and Digital Library Software


• Project Costing: Identification of Resources, Vendors and Price

• Feedback from Existing Clients of the Hardware
• Feedback from Existing Clients of Library Software
• Vendors for Hardware
• Vendors for Software
• Cost of Hardware
• Cost of Software
• Cost of Computer Stationary: CDs, Tapes, Labels
• Cost of Data Input, Editing and Validation.


Implementation Phases

– Project of Library Automation has to be implemented in Phases depending upon resources
» Phase I: Standalone Modular System on two workstations with single server. Data Input of Documents and Users
» Phase II: Multiuser System with add on Workstation and integration of other Hardware and Library Software Modules.
» Phase III: E-Resources Connectivity and Access to Global Resources
» Phase IV: Mulitmedia Corner in the Library.


Support and Upgradation

– Online Support for Library Software using Email, Phone and Knowledge Base
– Personal Visit to On-Site for Hardware and Software support
– Plug-ins and Upgrade Versions of the Software to support latest Information Technology
– Upgraded Manuals and Literature on Software functions.


Terms and Conditions

– Delivery Period
– Payment Conditions
– Warranty Period
– Support and Training Terms
– Annual Maintenance Contract
» Support
» Personal Visit
» Upgrades


Demonstration and Ordering
– Hardware Demonstration
– Library Software Demonstration with Library Professionals and Computer Professionals
– Report on Demonstration
– Approval of Hardware and Software
– Ordering of Hardware with Terms and Conditions
– Ordering of Software with Terms and Conditions


Installation and Training
– Hardware Installation and LAN Hardware setup has to be done by the Vendor
– Software Self Installation or Setup Installation on Standalone Machine
– LAN Installation of the Software with Server and Workstation Activation.
– Training on different Hardware
– Training on Library Software Modules.
• On-Site Training
• Centralised Regular Training Programme
• Computer Based Training (CBT) with Certification

Database Creation involves
– Pasting of Barcode Labels on the Documents according to Use of Collection
– Technical Processing of the Documents giving Classification Number, Subject Headings and Keywords etc.
– Input of Data from the Documents
– Editing of Records making corrections, deletion and additions.
– Validation of Records making standardisation

Running Library Automation Activities
• Test Run the Complete Library Procedures for various activities.
• Conduct Users Orientation Programme regularly.
• List New Information and Library Technology for Future incorporation.

MADE BY:

Dr. Shailendra Kumar (FOR CEC E COURSE)
Department of Library and Information Science
University of Delhi
E-mail: shail3@yahoo.com

ICT BASED INFORMATION SERVICES

Introduction

Technology helps in rendering services that were hitherto not possible using traditional means. The new information technology facilitates improved management of physical and financial resources. The advances in technology and its availability at lower cost, has also raised expectations of users from librarians and libraries. The new information technology, on one hand, facilitates wider access to information for the library users, on other hand, it facilitates wider dissemination of information products and services generated by the library. The availability of networks facilitates resource sharing and high-speed communication with other libraries.

The electronic resources and associated technologies are only a means to generate services keeping its potential users in mind. Like printed resources are used in traditional libraries to generate services by the library staff, the digital resources are used to generate services using software driven web-based interfaces. Computer programs substitute for the intellectually demanding tasks that are traditionally carried out by skilled professionals. Activities that require considerable mental activities, like reference service cataloguing and indexing, seeking information, etc. are performed by computer programs through web-based interface.

3. Internet; applications in Libraries

The emergence of Internet, particularly the World Wide Web (WWW) as a new media of information delivery, coupled with availability of powerful hardware, software and networking technology has further triggered large-scale commercial and non-commercial digitisation programmes the world over. Increasing number of publishers are using the Internet as a global way to offer their publications to the international community of scientists and technologists resulting in large-scale appearance of STM electronic journals on the web. The Internet and web technology provides an unparalleled media for delivery of information with greater speed and economy. Moreover, the web-based electronic information products not only eliminated paper, physical storage and transportation costs, it also offers a hosts of other possibilities for incorporating multimedia and hyper-link features to electronic documents hitherto impossible on paper media. The web-based electronic information products are exerting ever-increasing pressure on the traditional libraries, which, in turn, are committing larger portions of their budgetary allocation for either procuring or accessing web-based online or full-text search services, CD ROM products, online databases, multi-media products, etc. The libraries and information centres, as consumers of electronic journals and online databases, are benefiting greatly from this technology-driven revolution. The information products of technological revolution, in turn, triggered major shifts in the traditional practices and policies of buying, storing and accessing journals.

31. Internet Technology and Services

The Internet has revolutionised our society, our economy and our technological systems. Over the past century, important technological developments have created a global environment that is drawing people of the world closer and closer together. About fifteen years ago, most of the world knew little or nothing about the Internet. The Internet was then a private network accessible only to computer scientists and researchers who used it to interact with colleagues in their respective disciplines. Today, the Internet’s magnitude is thousand times more than what it was only a decade ago. It is estimated that about 60 million host computers on the Internet today serve about 200 million users in over 200 countries and territories. Today’s telephone system is still much larger: about 3 billion people around the world now talk on almost 950 million telephone lines (about 250 million of which are actually radio-based cell phones). Also, the total numbers of host computers and users have been growing at about 33% every six months since 1988 – or roughly 80% per year. The telephone service, in comparison, grows an average of about 5-10% per year. That means if the Internet keeps growing steadily the way it has been growing over the past few years, it will be nearly as big as today’s telephone system by about 2007.

The Internet has revolutionised the computer and communications world like nothing before. The invention of the telegraph, telephone, radio, and computer set the stage for this unprecedented integration of capabilities. The Internet is at once a world-wide broadcasting capability, a mechanism for information dissemination, and a medium for collaboration and interaction between individuals and their computers without barriers of geographic location. The Internet represents one of the most successful examples of the benefits of sustained investment and commitment to research and development of information infrastructure. Beginning with the early research in packet switching, the government, industry and academia have been partners in evolving and deploying this exciting new technology. Today, terms like “Yahoo” and “Google” are common part of our vocabulary.

New information technology can potentially support a range of traditional and non-traditional library services. Most of the library services generated using digital resources resemble closely to those generated manually with improvements and modifications to suit the requirements of automated services. However, digital resources have also been used to generate innovative services that did not have a counterpart in manual parlances. These services are:


4. Use of Internet for Supporting Traditional Library Activities

4.1 Acquisition and Collection Development

Amazon.com started a new phenomenon on the web with its online bookshop, which has been expanded to include other products like CDs, Music, electronics, toys, art works, computers, and other store items. Amazon.com was termed as the “Earth’s Biggest Library” (http://www.infotoday.com/newsbreaks/nb1122-1.htm) although it is not performing all functions of a library. There are several sites that are now in the business of online book selling. Most book publishers and bookstores announce their new books through their web sites. The libraries can use these sites as a source for acquiring information about new books for collection development and for verifying information on various aspects including costs, etc. some of the important sites that are in the business of online book selling are as follows:

Amazon.com Bookstore http://www.amazon.com/
Barnes & Noble http://shop.barnesandnoble.com/
Best Book Buys http://www.bestbookbuys.com/
Book Finder http://www.bookfinder.com/
Catalog Site http://www.catalogsite.com/
Pricescan Before You Buy http://www.pricescan.com
Studenstbookworld.com http://www.studentsworld.com/
Swotbooks.com http://swotbooks.com/
Varsitybooks.com http://www.varsitybooks.com/

Besides using Internet for selection of books in printed format, the libraries can also buy access to various types of electronic resources available on the Internet. The information resources available on the Internet can be taken into account in the process of collection development. The libraries of future will not become digital libraries, but will rather acquire access to ever growing digital collections on behalf of their users. Majority of these collections are being made available by external sources like commercial publishers, collections mounted by scholarly societies, resources at other libraries, electronic journal sites, etc. The electronic journals have become the largest and fastest growing segment of digital collections for most libraries. There are more than 20,000 peer-reviewed electronic journals that are now available in electronic form either exclusively or in addition to their print version.

Besides electronic journals, electronic books, encyclopaedia, dictionaries, directories, online databases, online courseware, etc. are also available on subscription / purchase model.

4.2. Technical Processing Books

The Internet can be used to access latest authoritative tools related to classification and cataloguing to render help in better processing of documents. Links to tools like Library of Congress Classification Schedule, LC Subject Headings, MARC documentation, OCLC User Documentation, other thesaurus and subject dictionaries available on the Web can render required help to the staff members involved in technical processing of books. The library can provide a monthly / weekly list of books acquired by the library through the library web site.

4.3. Journals Ordering and Management

Most publishers maintain their web site with subscription information about their journals that can help the staff involved in journal selection, ordering and management. Several web sites maintain meta resources with links to journals from various publishers. The library can provide a complete list of journals subscribed by it as well as weekly list of issues of journals received by it. List of complete journals holding of the library on the Web site would also enhance the usage. Link to union catalogue of journals subscribed by a group of libraries would help in resource sharing.

4.4. Reference Services

Number of reference sources available on the Web has increased exponentially during past one decade. The libraries can develop subject portals that would provide links to important reference sources through the Library web site. Meta sites like Xrefer provides a basket full of reference sources with a single search interface to help the users to retrieve information in a quick and efficient way.

5. Traditional Library Services Modified in the Internet Era

5.1. OPAC to WebPAC

Remote access to the Library catalogues was possible only through a telnet connection till recently. The web-based interfaces are now available for most of the integrated library software packages including Libsys. Web sites are increasingly providing links to their WebPAC instead of telnet links to their Library OPAC. Exploiting the provisions of hyperlinking that the web provides, various searchable elements of a bibliographic record in a webPAC are hyperlinks to other records in the database. For example, an author is a hyperlink to all records in the database for that author, a series is an hyperlink to all serial title under that series; a keyword for a record is a link to all records in database having that keyword, etc. In effect, a web PAC adds software-based functionality to a conventional OPAC. A user has additional incentives to visit the library web page hosting webPAC. With web-based resources and services in place, many libraries are phasing out their dumb terminals. The library web sites are increasingly becoming a more logical gateway to the catalogue and other web-based library resources. The acceptability of web-based interfaces to the Library OPAC is much greater because web interfaces are familiar to the users with its graphical and navigational interfaces. The users can click complex subjects instead of typing them in or remembering complex unix commands.

5.2. CD ROM to Web-based Indexes and Databases

Availability of CD ROM in late 1980s, as a media with high storage capacity, longitivity, and ease of transportation triggered production of several CD ROM information products which were earlier available through online vendors or as conventional abstracting and indexing services in printed format. Some of the important secondary services including “Guide to Current Periodical Literature” (H.W. Wilson) discontinued their print version in favour of CD ROM version which had improved functionality in terms of search and browsing interfaces. The libraries are witnessing yet another migration from bibliographic databases on CD ROM to web-based bibliographic databases akin to the one that was witnessed earlier from print based secondary services to CD ROM databases. This phenomenon has further been fuelled with availability of web-interfaces for most of the online search services. The web-based interfaces provide several advantages to users that are either not possible or not yet available on CD ROM. Most web-based bibliographic databases use hyperlinks and other facilities possible in a web documents including link to the full-text of articles to a publisher’s web site. Several bibliographic databases have discontinued their CD ROM version in favour of web-based version. Besides advantages mentioned above, migration to web-based services open-up resources to remote users.

5.3. From Manual Reference Service to Digital Reference Service

Reference service and imparting instructional training to the library users are key areas of activities for any library. The technology now allows reference librarians to reach out to the users using the network instead of waiting at the reference desk for users to come by. Besides, imparting instructions on mechanisms of using a library, a reference librarian is also involved in delivering reference service that require deep intellectual understanding of subject. Although automated libraries are not yet sufficiently advanced to offer interactive reference services, electronically-mediated reference services are increasingly available through libraries and information centres.

Digital reference service, also called “Ask-An-Expert” or “Ask-A-Librarian” services are Internet-based question and answer service that connect users with individuals who possess specialized subject knowledge and skill in conducting precision searches. As opposed to static web pages, digital reference services use the Internet to place people in contact with people who can answer specific question and instruct users on developing certain skills. The people who serve as digital reference experts (also called volunteers or mentors) are most of the time information specialists, affiliated to various libraries. Some of the different types of quick reference sources available online are named below:

Reference collections
Bartleby.com – This site offers a selection of ancient and modern titles in full text. The collection includes poetry, literature, essays and general reference works. Search by keyword, or browse by author, title or subject.

Dictionaries and thesauri
OneLook – This service will simultaneously search online dictionaries and glossaries worldwide for definitions. The collection includes both general and specialist reference sources, including works for art, business, computing, medicine, science, technology and slang.
Online Dictionaries – This page on the Higher Education & Research Opportunities in the United Kingdom (HERO) web site provides links to general and specialist dictionaries, thesauri and reference resources worldwide.
Thesaurus.com – This site uses Roget’s Interactive Thesaurus to provide synonyms for words and phrases.
World Wide Words – Compiled by lexicographer Michael Quinion, World Wide Words is an online guide to contemporary English and its usage. The site includes a collection of articles about the use and evolution of the English language; definitions of new and unusual words; a guide to phrases; answers to queries submitted by site visitors; and a notes about words currently featured in the press.
Abbreviations and Acronyms
Acronym Server – This is a database of general, technical and specialist acronyms. Enter an acronym to find its meaning, or search for a word that may appear within an acronym.

Quotations
Bartlett’s Familiar Quotations – The content of this site is taken from the tenth edition of Bartlett’s published in 1919. The collection includes examples from ancient and late nineteenth century authors. Search by keyword or browse by author name.
Quoteland.com – A collection of quotations from both ancient and modern authors, as well as contemporary commentators, political figures, celebrities and characters from fiction. Search by keyword or browse by topic or author name.

Maps and street plans
MapQuest – Offers online maps and street plans of countries worldwide. Use the zoom option to alter the scale of a map, and the North, South, East, West buttons to navigate your way around.
Multimap.com – Includes a complete interactive atlas of Britain. The free service will allow you to search by town, street name, or postcode. Aerial photographs are also available for many British locations.
Perry-Castañeda Library Map Collection – This broad online map collection from the University of Texas at Austin offers reference, political, shaded relief and historical maps from countries worldwide.
Atlapedia Online – This online collection offers both political and relief maps of countries around the world. Background notes on the the geography, history and economy of each country are also available, as well as brief demographic statistics.
http://www.eci.gov.in/ElectionMaps/ElectionMaps_fs.htm : Election maps of India.
http://www.khoj.com/Reference/Guides/Maps/ : Directory of Maps of India.

How does it Works? Most “Ask-a-Librarian” services have a web-based question submission form or an e-mail address or both. Users may submit questions by using either form. Once a question is read by a service, it is assigned to an individual expert for answering. An expert responds to the question with factual information and or a list of information resources. The response is either sent to the user’s e-mail account or is posted on the web so that the user can access it after a certain period of time. Many services have informative web sites that include archives of questions and answers and a set of FAQs. Users are usually encouraged to browse archives and FAQs before submitting a question in case sufficient information already exists.

Virtual Reference Desk (http://www.vrd.org/) provides resources and links to experts that offer digital reference services. The site hosts searchable database of high quality “ASK-A” service along with alphabetical and subject wise listing. Virtual Reference Desk also hosts a listserv called “Dig-Ref” to promote and explore the growing area of digital reference services.

5.4. From Manual Reference Service to Real time Digital Reference Service: Library Chat Rooms

Several libraries have started experimenting with offering real time digital reference service, using chat software, live interactive communication activities, call counter management software, web contact software, bulletin board services, interactive customer assistance system or related technologies.

Many libraries are experimenting with Internet chat technology as an innovative method to extend and enhance traditional and remote reference service. While digital reference service is asynchronous method of information delivery, the Internet chat providing the benefit of synchronous communication between a user and a reference librarian (or mentor). Interactive reference services facilitate a user to talk to a real, live reference librarian at any time of day or night from any where in the world. Unlike with email reference, the librarian can perform a reference interview of a sort by seeking clarifications from the user. The librarian can conduct Internet searches and push websites onto the patron’s browser, and can receive immediate feedback from the patron as to whether his or her question has been answered to his satisfaction. Most libraries currently involved in real-time reference service are part of a collaborative network so that they can share staffing and work around the clock to truly provide reference service any time. Library of Congress Collaborative Digital Reference Service is one of such services. Several institutions including Cornell University, Internet Public Library, Michigan State University, North Carolina University are offering Internet chat-based service using software like LivePerson, AOL Instant Messenger, Conference Room and Netscape Chat. The librarians have observed that their relatively new chat-based service logged significantly more questions in a relatively short time than did their well established e-mail digital reference service. LiveRef(sm) (http://www.public.iastate.edu/~CYBERSTACKS/LiveRef.htm) maintains an online registry of real-time digital reference services.

5.5 “Groupware” as Knowledge Repository (E-Reference)

In the corporate world, collective, experiential information gathered over the years, are called “institutional knowledge.” Recently discovering the value of this commodity, companies have invested heavily in knowledge management systems that collect, store, redistribute, and ultimately leverage this corporate information in support of profit. Likewise, busy IT departments use Q&A knowledgebase and ticketing systems to help manage the on-slaught of daily IT questions. Regardless of its name (a knowledgebase, ticketing system, or a knowledge repository), a modern library may need a formalized system to preserve local reference knowledge and to facilitate reference collaboration.

So how would a knowledge repository work in a library? Suppose, a user e-mails a question to the Reference Librarian. When the reference coordination logs into the knowledgebase, he is immediately alerted to the new electronic request, made by the patron. He performs a keyword search in the knowledgebase and finds two similar reference questions in the archive. The archived questions may not exactly match the current one. So, he refers the query to a subject specialist. A third librarian, who is monitoring the activity in the reference system, posts a message about his dealings with similar types of questions, if any, in the recent past at the reference desk. The subject specialist responds immediately, sending an answer directly to the patron and routing the answer to all of the reference librarians. In this example, the subject specialist is the one who answered the question, but everyone contributed to the solution.

OCLC’s Question Point software/service is an excellent application of this kind of collective reference service; it facilitates interlibrary reference services to a great extent. While reasonably priced, the Question Point service may still be just beyond the budget constraints and needs of some smaller libraries. There are several open source reference service management packages available. Many smaller libraries don’t need a full-fledged reference management system. But, these smaller libraries may always have the basic components to create a simple, question management system.

Over the last 7 years or so, the e-mail server industry has moved beyond basic e-mail to a more powerful product category called groupware. As the name implies, groupware facilitates collaboration within an organization through e-mail, calendaring, contacts, project management, and scheduling capabilities: It’s about information sharing. If you are not sure if you have groupware, you might want to check with your systems administrator. Some common groupware products are Microsoft’s Exchange Server, Lotus Notes, and GroupWise.

Groupware provides the means for increased collaboration and information transfer, this type of product be used to share the work on reference questions? To build a collaborative knowledgebase with as “Ask a Librarian” form forwarding queries to a departmental e-mail account. The next step is to share this centralized account with all of your reference librarians. This simple act of information sharing brings big benefits: All of your librarians can see, learn and contribute to the reference questions as they come through the departmental e-mail account. In an academic library, you know that entire classes with a common assignment are likely to cycle through the library with a specific reference question.

However, certain personal/cultural workplace prerequisites, considered to be necessary for such systems to work, are, Reference skills and a “safe” environment, where collegiality is fostered. Collaboration, electronic or otherwise, almost never happens in a hostile work environment. Given the proper resource-sharing environment, a participant library simply has to type the question it has come across and the answer in an e-mail message and send it to the reference account. Then all the reference librarians will have access to these “in-person” transactions. Another great feature of groupware is the ability to search every e-mail via keyword. For those who still don’t want to deal with the vagaries of keyword searching, are allowed by most groupware applications to organize the e-mail in electronic folders. In this way one can classify the reference questions any way --by subject, patron, or date. Groupware can function as a simple knowledgebase and collaborative tool. Groupware applications also feature group calendaring functionality.

Another helpful feature is that the system automatically generated a reassuring e-mail to the patron. This e-commerce technique can easily be replicated in most groupware applications, without requiring difficult scripting skills.

5.6 Current Awareness Service.

There is a wide variety of CAS methods and also specific products. The more conventional or traditional methods include accession lists, newspaper clippings, current awareness bulletins, displays, abstracting bulletins, periodical circulation, photocopies of the tables of contents of periodicals, indexing and abstracting journals, internally produced abstracts and indexes, press clippings, personal notifications and selective dissemination of information (SDI). To this can be added electronic tables of content, electronic newsletters, electronic news alerts, electronic notification systems, push services, pre-print archives and alerts offered by search engines. CAS is now been made available via the World Wide Web (WWW or Web). There is a whole range of services that go under different names for example Table of contents services, push technology, webcasting, intelligent agents, e-zines and newswires, etc. Some of the services are available for free or at a modest fee, while others are fairly expensive and definitely aimed at the corporate market. Some services provide automatic notification, for example via e-mail, while others require users to visit their sites on a regular basis. There are numerous CAS available via the Internet. The following categories can be covered under CAS: table of content services, automatic notification from tables of content, book alerting services and e-mail notification from publishers, SDI or alerting services available through aggregate services, alerting services available through search engines and meta-indexes, e-newsletters and e-zines, newspaper filtering services and newspapers, monitoring through intelligent agents, website update notification services, web pages with newsworthy content, weblogs, discussion groups and electronic mailing lists, etc.

5.7 Tables of content services

Tables of content services are not new to librarians; they are now, however, also available via Web. The WWW services are much more up-to-date than their printed or CD-ROM counterparts, and much more convenient to use. Tables of content services allow users to scan the tables of contents of new as well as backdated issues of journals. These are especially useful in keeping track of new publications on a variety of topics. Such services are offered mostly by aggregator services such as Ingenta or directly by publishers. Ingenta also offers a document delivery service. The advantage of aggregator services is the diversity of titles from various publishers that they offer. Users can subscribe to these services for free, or for a modest fee. The subscriber selects the journal titles they are interested in and as soon as a new issue of a journal is available, they receive an e-mail message with the table of contents.

There are also the services of a more limited scope that may be of interest to librarians. BUBL (Bulletin Board for Libraries) offers tables of contents and abstracts for major Library and Information Science (LIS) journals. BUBL however, does not provide e-mail alerts so that one has to visit the site on a regular basis. Current Contents (Social and Behavioral Sciences), EBSCO Alert, Emerald E-mail Alert Service, and Science Direct also offer excellent opportunities for librarians and users. These services are, however, expensive to subscribe.

5.8 Automatic notification from tables of content

The latest literature can also be identified through the use of automatic notification from tables of content as provided by publishers, such as Elsevier ContentsDirect, Ideal: International Digital Electronic Access Library and SARA. Although there are many other publishers such as Audio Books: Chives Press, Blackwell, Cambridge University Press, De Gruyter, Institute for Scientific Information, Kluwer, Whitaker, Wiley, and Wilson librarians should focus on publishers relevant to their field of interest. Some publishers do not offer automatic e-mail notification. They do, however, post the tables of content on their websites, where it is free to check it on a regular basis for new books, articles, reports, etc. Sometimes (e.g. as is the case with Searcher) some of the articles are available for free in full-text format. It is therefore useful to identify a list of journal titles of potential interest and to ensure that one checks them either through a table of contents service, automatic updates from publishers or by regularly visiting the journal’s website. There are many such LIS journals like Diglib, Ariadne, Interlending & Document Supply, Journal of Academic Librarianship, Library Collections, Acquisitions & Technical Services, Online Information Review, etc.

5.9 Book alerting services and e-mail notification from publishers and vendors

New book or other document titles (e.g. videos, CDs) can be identified through automatic notification services according to an interest profile of broad categories. These services are offered by book alerting services such as Amazon.com, Barnes and Noble, Ingenta, etc. Some of these service and most of publishers such as Elsevier Science also offer free e-mail alerting services. Such services are extremely important to know about new titles in the disciplines of once interest. New publications (books, journals and other document types) can also be identified through a number of resources created especially for the use of librarians. These include The Bookwire Index (Publishers) and Directory of Publishers and Vendors (available via AcqWeb).

5.10 SDI or alerting services available through aggregate services

SDI services (also known as alerts or alerting services) involve the automatic notification of users when new records are added to the database. The records are matched against a search strategy reflecting the user’s interest profile. In the case of SDI services, the search strategy is often referred to as the search profile. There are a variety of SDI services available through aggregate services such as Emerald, Dialog, SilverPlatter, ScienceDirect, or EbscoHost. These services are very useful for keeping oneself abreast with latest publications in the field of interest. These services are, however, expensive to subscribe. Databases such as Library and Information Science Literature, Library Information Science Abstracts, and Library Literature are quite useful for the librarians.

5.11 Alerting services available through search engines and meta-indexes

NorthernLight is one of the very few search engines offers free e-mail alerting service. It is based on one or more interest profiles, and whenever the search engine picks up new sites relevant to the profile, the user is notified. Steven Bell’s Keeping Up Page is also a useful meta-index. These services can be used in addition to SDI services available through aggregate services to keep one self updated in the subject field of interest.

5.12. From Manual Document Delivery to Electronic Delivery Services

Abstracting and indexing services have proved themselves as most effective means of finding recent and retrospective published research work. The effectiveness of these secondary services are further enhanced with availability of these secondary services on CD ROM with efficient search interfaces and other features that are possible only in electronic media.

Once a researcher gets bibliographic references relevant to his research work, the more arduous task of locating the full-text of research article begins. While the parent library may cater only to 10 - 20 % of his references, remaining articles may have to be arranged through Inter Library Loan (ILL) or through Document Delivery Services (DDS) which can be very time consuming. Most Library use commercial (Informatics India) and non-commercial (BLLD and INSDOC) document delivery services to ensure quick and efficient access to primary information for the library users. Most online search services like DIALOG, ESA /IRS and STN have been offering manual document supply services since their inception. The process is labour-intensive and time consuming.

The term “electronic document delivery systems” implies delivery of electronic version of a document that might involve reproduction of an electronic copy of a document if it is not already available in electronic format. The libraries had been using fax machines for immediate delivering photocopies of articles via telephone lines. The first use of electronic document delivery was based on scanning technology. With maturity of scanning equipment and technology, document supply services started scanning the documents as bitmap page images. Applications are built in such a way so as to automatically produce a hard copy together with a header page containing the address of the applicant which can again be send by snail mail or facsimile. A software package known as “Ariel” is used in several libraries in developed countries for delivery of scanned articles via the Internet. The Ariel software is loaded on an Internet-enabled computer can receive and send electronic information to other libraries which have installed Ariel. The ADONIS system developed in late 1980s is a document delivery system based on bit-mapped page images.

Availability of most of the peer reviewed research journals in electronic format, inexpensive technology to scan articles and improved electronic delivery mechanisms are some of the enabling factors that have contributed to well-established electronic document delivery system now available commercially. More recently most of the secondary services that were available on CD ROM or through online search services are now available on the Internet where the journals are linked to the publisher's site. The technology has now been perfected and there are several electronic document delivery services that allow a user to download an article in full-text from their site or deliver them electronically as attachment to e-mails. Most electronic publishers and aggregators like OCLC, Blackwell, OVID, etc. are offering document full-text of articles through their web sites. Different vendors have various payment options; some charge each time the journal is used, whereas others provide open access for a set annual fee. A user who wishes to have the item delivered can enter a credit card number and specify a delivery method (postal, UPS, fax, e mail, etc.) and indicate whether it is a rush item (with a rush order fee attached.)

The ADONIS (Article Delivery Over Network information Systems) can be considered as a landmark development in electronic document delivery system. The project was launched by a consortium of five major publishers - Academic Press, Blackwell’s Scientific Publications, Elsevier Science Publications, Pergamon Press and Springer Verlag. The project uses combination of laser scanning, printing and digital optical storage technology for storage and retrieval of complete pages of over 650 scientific, technical and medical journal articles. The issues of journals are available on CD ROM with weekly updates for distribution to each centre in various countries licensed to use the system for document delivery.

Some of the important Electronic Document Delivery Services include:

• Uncover http://uncweb.carl.org/uncover/subtitle.html
• Articles in Physics http://ojps.aip.org/
• Bioline Publications http://bioline.bdt.org.br/journals
• Chemport http://www.chemport.org/
• ScienceDirect http://www.scienceDirect.com/
• OCLC www.oclc.org/
• Northern Light www.northernlight.com/

6. Internet-based New Library Services

6.1. Virtual Library Tours

Several library web sites facilitate virtual guide to the physical facilities including collections, services and infrastructure available in the library through their web sites. The combination of the following three web-based interfaces are used to facilitate the virtual library tours:

6.2. Library Maps and Floor Plans

Most library web sites provide library layouts and floor plans to guide users to physical location of facilities and services along with link to relevant information. Client-side image maps are used to make various parts of floor plans as clickable image maps. An example can be seen at the Central Library Home Page of the Central Library, IIT Delhi at: http://www.iitd.ac.in/acad/library/layout.html

6.3. Photographic Views

A view of 360° photographic environment using plug-ins like Quick Time and iPix are available at a few library sites. Examples can be seen at Botsford General Hospital Library site. (http://www.botsfordlibrary.org/tour.html).

6.4 Library Web Sites

Academic libraries in developed countries started using web technology to create home pages as starting points or as gateways for searching information about the library. A home page reflects characteristics of an academic institution. It provides an opportunity to the library to propagate its services and facilities to the academic community worldwide. The home pages of libraries are increasingly used as an integrated interface designed to deliver detailed information about a library as well as to provide access to all computer-based services offered by a library.

Besides offering information, the library web sites of academic institutions invariably hosts subject gateways or subject portals that contains links to web resources for subjects of interest to the institution. Most of the services (modified or new) included in this article are offered through the web sites of most of the academic institutions especially in developed world. The IIT Delhi Central Library also offers several of these services through its web site available at http://www.iitd.ac.in/library/.

6.5 Library Portals

A library Portal is a site on the World Wide Web that typically provides information about library to its visitors, users, patrons and also providing a pathway to other content. It is designed to use distributed applications, different numbers and types of middleware and hardware to provide services from a number of different sources. In addition, library portals are designed to share collaboration in workplaces. A further requirement of portals is that the content be able to work on multiple platforms such as personal computers, personal digital assistants


6.6. Subject Gateways

The web, being a hypermedia-based system, allows linking amongst electronic resources stored on servers dispersed geographically on distant locations. The portal sites or gateways redirect a user to the holders of the original digital material. The librarians, being the earliest inhabitants on the web, and following their professional instincts, immediately began to create link to collections on all sorts of subjects.

A subject gateway can be defined as facility that allows easier access to web-based resources in a defined subject area. The simplest types of subject gateways are sets of web pages containing list of links to resources. Some gateways index their lists of links and provide a simple search facility. More advanced gateways offer a much-enhanced service via a system consisting of a resource database and various indexes, which can be searched and / or browse throughout a web-based interface (O’Leary, M., 2000).

Subject gateways are also known as Subject-based Information Gateways (SBIGs), subject-based gateways, subject index gateways, virtual libraries, clearing houses, subject trees, pathfinders and other variants thereof. Subject gateway is an important component of a library web site designed for the library users so as to help them discover high-quality information on the Internet in a quick and effective way.

In the traditional information environment human intermediaries, such as publishers and librarians, filter and process information so that users can search catalogues and indexes of organized knowledge as opposed to raw data and information. Subject gateways work on the same principle, i.e. they employ subject experts and information professionals to select, classify and catalogue Internet resources to aid search and retrieval for the users. Users are offered access to a database of Internet resources descriptions which they can search by keywords or browse by subject area. A description of each resource is provided to help users assess very quickly its origin, content and nature, enabling them to decide if it is worth investigating them further. In the process users get benefited from the expertise of librarians and subject experts with subject gateways rather than having to locate, evaluate, filter and organize the resources themselves. Specialized software are available as freeware or as priced software to create and maintain professionally developed subject gateways. Some of the major portal sites or gateways that provide access to electronic resources on the Internet are as follows:

• WWW Virtual Library http://www.edoc.com/
• Internet Public Library http://www.ipl.org/
• Michigan Electronic Library http://mel.lib.mi.us/
• Penn Electronic Library http://www.library.upenn.edu/resources/
• BUBL Information Service http://bubl.ac.uk/
• Argus Clearing House http://www.clearinghouse.net/
• Internet Index http://sunsite.berkeley.edu/InternetIndex/

6.7 Full Text Resources

Full text resources are increasingly available on the Internet. A few are listed below. You might want to find more of your own through the search engines listed above.

New York Times (www.nytimes.com)
The New York Times on the Web provides access to that newspaper’s articles. You are requested to register, but at least until now, no fee is assessed.

The On-Line Books Page (http://digital.library.upenn.edu/books)
An Index of books online indexes over 11,000 on-line books. Search or browse by author, title, new book listings or subject. A rich collection with numerous book related links.

Tales of Wonder: Folk and Fairy Tales from Around the World
(http://members.xoom.com/darsie/tales)
Tales of Wonder was created by Richard Darsie. This site has full text of a variety of folktales. There are a number of interesting links from his home page including an award winning set of poetry links, cooking links and music connections.

A Children’s Literature Web Guide (www.acs.ucalgary.ca/~dkbrown/index.html)
A Children’s Literature Web Guide offers children’s bestsellers in Canada and the United States, conference and Book related events and reviews online.

BookWire (www.bookwire.com)
Book Wire is developed by R. R. Bowker and includes connections to their periodicals, e.g. SLJ, LJ, etc. The site also includes reports on author tours, provides excerpts from review sources for prose and poetry and includes awards listings.

Project Gutenberg (www.promo.net/pg)
Project Gutenberg is a collection of full text books no longer copyrighted that is continually augmented. This site is set up for full text searching via author or title indexes. A number of sites provide links to this resource.

CTHEORY (www.ctheory.com)
CTHEORY, an electronic review of books, international in scope, is a bit esoteric but the authors make some interesting observations about society in general and books and electronic information in particular.

African American Web Sites (http://home.earthlink.net/~anthony/africa.html)
African American Web Sites links to a number of sites of interest to African Americans and to multicultural curricula.

Britannica.com (www.britannica.com)
The entire contents of Encyclopedia Britannica is available at this Web site. Searchers can access information using a directory of topics or a search engine. Advertising does appear in this version of Britannica. The electronic version of Encyclopedia Britannica that is advertising free and includes more sophisticated search options is available at www.eb.com for a subscription fee.

6.8. Web-based User Education

The www provides a dynamic environment for distributing information over a large network and web-based instructions is a suitable tool to do so. Web-based guides and teaching tools can be easily updated, accessed, and printed on demand. They may include colour graphics, and screenshots. The web-based user education provides a high degree of interactivity and flexibility to the users offering them the benefit of self-pace, graduated to teach from basic to highly advanced levels and designed in a wide range of formats that accommodate diverse learning styles. The proliferation of digital resources will generate greater demands on reference and instructional services. With availability of digital resources that can be used any where at any time, requirement for instructional and reference services would also grow. Failure to develop both the technological aspects and required service components would lead to under utilization of digital resources. The library web sites can use web-based user education for imparting training to users in the following area:

• Basic library skills along with glossary of library terms;

• Using Library OPAC / WebPAC, locating books, magazines and other library materials;

• Instructions for searching CD ROM and web-based databases and other electronic resources; and

• Instructions on subject searching training, using Boolean operators and searching Internet resources through search engines.

The web technology provides for incorporating both synchronous and asynchronous interactivity in the web-based user education.


MADE BY

Dr. R. K. Chadha (MADE FOR AN E COURSE OF CONSORTIUM FOR EDUCATION AND COMMUNICATION)
Jt. Secretary
Lok Sabah Secretariat
Parliament Library of India
New Delhi
E-mail: chadha@nic.in, ravichad@gmail.com