`
`LOCAL AREA NETWORKS (LANS) AND THEIR APPLICATION IN
`LIBRARIES
`Pradeepa Wijuntunga
`
`The Central Library
`University of Colombo
`Colombo 3, Sri Lanka
`
`Keywords: Local Area Network, LAN, Network, WAN, Wide Area Network, MAN, Metropolitan Area Network,
`Developing Country, Communications, Communication Media.
`
`Abstract: Networks can be defined as a collection of independent computers and other devices interconnected by
`a communication medium, such as coaxial cables, twisted pairs of optical fibers. Local Area Network (LAN) can
`be defined as a collection of computers and peripherals interconnected within a limited geographical area. This
`area may be one building or one campus within a few kilometers. Out of different types of Networks, LANs can
`be distinguished by its private ownership, its high speed, and its low error rate.
`
`The advantages of LANs can be pointed out as
`
`• resource sharing
`• central control of equipment and data
`• easy connection of equipment from different vendors
`
`LANs have been used in developing countries to improve the library facilities in an effi-cient manner. Using these
`applications as examples, we can apply the LAN technology in our libraries to enhance the services in the
`following manner.
`
`Application of LANs in Libraries:
`
`• Housekeeping applications - acquisition, cataloguing, circulation control.
`• Educational programmes - user education from distance and other study programmes.
`• Office administration - connection to administration offices for easy access of necessary files.
`• Connection with other libraries - inter library loans and electronic journals.
`This paper intends to address this topic in greater length.
`
`1. INTRODUCTION
`
`This paper initially gives a basic introduction of Local Area Networks (LANs). The author does not provide a detailed
`discussion of this section since it is not the scope of the paper and also because a detailed description could have taken a
`highly technical nature. Secondly, the paper deals with the application of LANs in libraries with some examples from
`the applications in developed countries. Finally, the barriers which we, the developing countries, encounter in the
`application of LANs in our libraries are outlined.
`
`2. WHAT ARE LOCAL AREA NETWORKS
`
`Although the term "Networks" can be interpreted in a number of ways, in our context we can interpret it as a collection
`of computers and peripheral devices interconnected by a communication medium such as, coaxial cables, twisted pair
`wires and optical fibers. Three major categories of networks can be identified, based on their geographical coverage, as
`follows:
`
`• Wide Area Networks (WANs): Computers and peripherals which are interconnected over a geographical area of 10 or
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`GOOGLE 1013
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`LOCAL AREA NETWORKS (LANS) AND
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`more kilometers belong to this category. Usually they cover the entire country.
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`• Metropolitan Area Networks (MANs): This is the type which covers a single metropo-litan area.
`
`• Local Area Networks (LANs): "...are concerned with the interconnection of items of computing equipment (office
`workstations, intelligent instruments etc.) which are distributed over a localized area such as a university campus or
`process plant. They are referred to, therefore as Local Area Networks". (Halsall, 1988).
`
`LANs can be distinguished from other networks because of their short distance. The total coverage may be from 1 km to
`10 kms. The data transmission speed of LANs is much higher than in other types of networks. When a WANs works at
`a speed of 1 mbps, LANs can transmit data at a speed of 1 - 10 mbps. The error rate in data transmission is slow because
`of the shorter distance between the equipment. Since LANs are within a single building or a smaller area, they are
`owned by the specific organization. This localized control provides greater flexibility in LANs than other types of
`networks.
`
`2.1. Evolution of LANs
`
`In the 1960s, the computers predominantly used were mainframes and only a few organizations were able to afford them
`because of their high cost. The concept of time sharing was popular during this period. Harnessing a dumb terminal to
`the mainframe by using a telephone line and leasing or sharing the computer time was the common practice. The major
`problem was the slowness of the computing process.
`
`With the advent of minicomputers in the 1970s, a solution for this problem was found. It could accommodate several
`terminals and more and more people were able to afford mini computers. Proliferation of minis led to the necessity of a
`communication between them in order to share the data stored in them.
`
`Computer resources in the organizations further increased with the arrival of microprocessors and the advanges of
`integrated circuit technology. (Halsall, 1988). It soon became common to find a multiplicity of products by different
`manufacturers physically located within the same building. Although they could act as autonomous computers, it was
`often required to establish a communica-tion with each other. As microcomputers became more and more powerful and
`less and less expensive, more people were using them and having their own databases and exchanging data. The
`communication facility provided is referred to as a private Local Area Data Network. Therefore, it is clear that only with
`the arrival of microcomputers that implementation of LANs were possible and necessary. (Schatt, 1987).
`
`2.2. Components of a LAN
`
`Each workstation of the LAN, which can be a microcomputer, a barcode reader or a word processor can work as an
`autonomous equipment, but they are connected to a central controlling unit, through which they can communicate (
`exchange data, share software or hardware ) with other workstations of the network. Though each workstation can act
`independently, they are not capable of controlling the activities of other stations of the network. To avoid corruption or
`collision of data during communication, several techniques like Career Sense Multiple Access/Collision Detection
`(CSMA/CD) and Career Sense Multiple Access/Collision Avoidance are used to control the transmission of data.
`Further information on these techniques will not be given here since it lies outside the scope of this paper. Figure 1
`shows the basic components of a LAN (Collier, 1988).
`
`• Communication medium: there is some kind of medium to connect all the workstations and other equipment together.
`
`• File server: a computer dedicated to providing shared access to a main storage device.
`
`• Print server : a computer dedicated to providing shared printing facilities.
`
`• Gateway : a computer providing access to other networks.
`
`• Workstation: a user's computer or any other equipment.
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`LOCAL AREA NETWORKS (LANS) AND
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`2.6 Types of LANs
`
`LANs can be divided in to two categories based on their topology and communication media. According to topology
`LANs can take several forms but three core forms can be identified easily as follows:
`
`• Star. Each workstation is connected to the control unit in the form of a star. Communication between two workstations
`has to be done through this central controller. A particular station which wants to communicate with another station
`builds up a connection, through the central controlling center, with the destination. Once this connection is established
`data can be communicated from one to the other station.
`
`• Ring. This category has no central controller but devices are joint together in a form of a ring. Data has to pass some
`other workstations to reach its destination. " A station wishing to trans-mit waits until its turn and then places a data
`packet on to the ring. This circulates around until it reaches its destination where the node copies the data into a local
`buffer. The packet then continues to circulate until arrives back at its source. This then provides a form of
`acknowledgment." (Winfield, 1984).
`
`• Bus. This takes the form of a data highway connecting all equipment to a linear communica-tion media. A
`transmission from any station can be received by any other station like in the ring type. Hence there is no sufficient data
`security in these types. " Obviously if all these devices started transmitting at once there would be chaos, so only one
`device is allowed to 'talk' at any one time. A form of access control is enforced to determine who can transmit next. The
`most commonly used medium access control is known as Career Sense Multiple Access with Collision Detection."
`(Winfield, 1988).
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`2.7 Communication Media
`
`Based on the type of communication media used to connect the workstations LANs can be divided into three groups.
`
`• Twisted pair wires. This is the most common form of wiring and the cheapest. Consists of two identical insulated
`wires wrapped together in a double helix. Twisting the wires together reduces the noise - any noise emanating from the
`environment or the communication medium, which is not a part of the message to be communicated.
`
`• Coaxial cables. This is a copper conductor surrounded by one or more foil or braided wire shields, each separated by
`the other by some kind of plastic insulator.
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`LOCAL AREA NETWORKS (LANS) AND
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`• Optical fibers. This is the latest form of communication medium which consists of thin strands of glass enclosed in an
`insulator. These are light in weight, but the cost is still high. Needs expertise in installation, but the data security is very
`high, since any tapping of the lines can be detected easily due to the disturbances of the light signals.
`
`2.8 Advantages of LANs
`
`LANs are used mainly for resource sharing. Expensive hardware like laser printers and CD/ROM drives can be shared
`by several users when they are attached to a network. Further, purchasing a network version of software cuts the costs of
`purchasing them for each and every computer.
`
`Central control of equipment and data provides easy administration, better data security and more flexibility in changing
`the system.
`
`Instead of purchasing a multi-user system, the available equipment from different vendors can be connected together
`using a network.
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`3. APPLICATION OF LANS IN LIBRARIES
`
`Although Local Area Networks have been in existence for some time, their use is fairly recent in the field of libraries.
`The initiative steps were taken by the American and British libraries. By taking their applications as examples, we can
`make an attempt to adopt this interesting technology in our libraries too. The following sections will describe how
`LANs can be used in a library environment.
`
`3.1 Housekeeping Applications
`
`In several libraries LANs have been used to assist the housekeeping applications or it would be more correct to say that
`test projects were undertaken to experiment on this aspect. A good example is the University of Aston (UK) LAN
`installation project where they concentrated on acquisitions, cataloguing and circulation control. (Brindley, 1987).
`
`• Acquisitions. The users of the library for e.g. the academic staff of the university depart-ments can directly send their
`book orders to the acquisitions department via the LAN, and also they can keep a track of the books received
`conveniently through the LAN. These orders could be directed on-line to the book seller if a gateway is available to
`their network. Blackwell's PC ORDER system caters for this type of book ordering. Once a connection is established
`between the finance branch of the parent organization and the library, a correct record of expenditure can be obtained
`without delay, which will enable the proper utilization of funds.
`
`• Cataloguing. The requirement of a union catalogue can be eliminated when a LAN is avai-lable since each branch
`library can have their own catalogues in site and provide access to other catalogues via the network. This saves the time
`of the users by eliminating the requirement to visit each branch library in search of books. Further, when cataloguing the
`material book details can be obtained from the acquisitions department where most of the bibliographic details are
`available. The cataloguing staff will only have to add what is not there.
`
`• Circulation control. The facility of returning the books at any branch library within the geographical coverage of the
`LAN could be provided in order to save students time, but of course the books will have to be delivered to the respective
`library at the end of the day. Checking details of delinquent borrowers could be easily traced when circulation data are
`attached to a network.
`
`3.2 Educational Services
`
`LANs can be utilized in the library for educational purposes too. Aston University has made plans for two types of
`services. (Brindley, 1987). They were going to provide an on-line database advisory with trained staff for users engaged
`in a remote database search and secondly they were having plans to run tutorial classes in on-line searching
`simultaneously in different locations. In this manner there users will have a better understanding of the electronic media
`with which they have to interact in the library. Staff time and money will be saved by providing training for a larger
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`LOCAL AREA NETWORKS (LANS) AND
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`group of students simultaneously. Computer conferencing which uses several remote computers attached to a network to
`conduct a conference without the actual gathering of participants to a single venue, is another application of LANs
`which could provide a sophisticated service for the future library users. The LAN installation in the Department of
`Information, University of Strathclyde has been employed to carry out an experiment on computer conferencing and the
`author asserts that, despite the ergono-mic and technical problems, computer conferencing and electronic journal
`production have consi-derable potential and appeal (Baird, 1987).
`
`3.3 Resource Sharing
`
`Installing high cost hardware like CD/ROM drives and readers in a LAN allows sharing of them by a multitude of
`library users. This in turn will reduce the cost of purchasing several of them for a single library. Thomas P. O'Neil
`Library of Boston College (USA) has installed Multiplatter which is a CD/ROM Local Area Network designed by
`Silverplatter to allow multiple users to access the same CD/ROM disc at the same time. (Grant, 1989). Where software
`is concerned, several copies have to be purchased if several computers are using them. But purchasing a network
`version of the software, (of course at a higher price than a single version but lesser than several copies)to be installed in
`the LAN makes things much easier. The principal reason for establishing the LAN at the R.H. Fogler Library of the
`University of Maine, Ohio was to ease the burden of handling requests for software, which includes Dbase3 Plus, word
`processors, course specific discs etc. used by the students. (Flower, 1988).
`
`3.4 Office Administration
`
`The library office could be connected to various other offices, for instance personal, finance and welfare branches etc.
`To avoid wastage of time used to obtain information manually from different branches, LANs can be employed to
`transfer data, with a certain amount of security, to the library office. Using the concept of electronic mail library staff
`could be contacted easily instead of calling for meetings, further electronic mail facility could be used to prepare news
`letters and memos to be circulated among the library and through a gateway among other libraries too. However the
`ASLIB/BLRDD LAN project says that this function was soon tailed off. (Copeland, 1986). It further says that NCC has
`established that everybody should have the discipline to check for the incoming mail for this to be a success. (Copeland,
`1986).
`
`4. CONSTRAINTS ENCOUNTERED IN APPLYING LANS IN THE LIBRARIES OF DEVELOPING
`COUNTRIES
`
`We have been unable to reap the full benefits of LAN technology in our libraries, mainly because most of our libraries
`are not yet automated in its true sense. Automation is still limited to one or several microcomputers and a limited
`number of applications. Predominantly the application auto-mated is the library catalogue. In that also, a fully
`automated On-Line Public Access Catalogue is rare. Until computerization is in the full swing, or at least several of our
`library procedures are automated we cannot actually feel the necessity of communication between the different
`workstations in the library.
`
`Secondly, the absence of qualified professionals in the field of library automation, has contribu-ted immensely to this
`issue. It should be emphasized here the problems we encounter in training our librarians, especially providing them with
`a training, so that they could be on par with their counter-parts from the developing countries. Hence the information of
`availability of technology does not reach our libraries adequately.
`
`Thirdly, as a core cause of the two reasons shown above, the scarcity of financial resources could be pointed out.
`Procuring of electronic data processing equipment, suitable software and establishing sophisticated communication links
`which is essential for LAN applications, is impaired by the direction of national resources towards more basic need
`satisfaction.
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`5. SUMMARY
`
`LANs can be defined as the interconnection of computers and peripherals within a limited geographical area, and they
`can be distinguished, based on their topology and the communication media used to interconnect the equipment.
`Application of LANs in libraries were initiated in American and British libraries. Housekeeping applications,
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`LOCAL AREA NETWORKS (LANS) AND
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`educational services, resource sharing, and office administration are the major areas in which LANs can be applied in
`libraries. Yet, this technology is still not employed in the libraries of developing countries because of the computer
`applications are not yet wide spread to feel the necessity of networking, because of the lack of technical knowledge of
`the librarians and above all, because of the lack of financial resources to overcome the first to problems.
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`REFERENCES
`
`Baird, Patricia M. & Borer, Beatrice. (June 1987). "An Experiment in Computer Conferencing Using a Local Area
`Network," Electronic Library, 5 (3): 162-169.
`
`Brindley, Lynn. (May 1987). "Planning for Library and Information Services Over a Campus Wide Network," Netlink, 3
`(3): 4, 6-9.
`
`Collier, Mel (ed.). (April 1988). "Telecommunications for Information Management and Transfer," Proceedings of the
`First International Conference, Leicester Polytechnic. London: Gower.
`
`Copeland, Joyce. (March 86). "The ASLIB/BLRDD LAN Project," The Conclusion Netlink, 2 (2):
`
`4-9.
`
`Flower, Eric & Thulstrup, Lisa. (September 88). "Setting Up a Public Use Local Area Network," Wilson Library
`Bulletin, 63 (1): 45-47.
`
`Grant, Marilyn A. & John C. Stalker. (September 89). "The Muliplatter CD/ROM Network at Boston College. Laserdisc
`Professional 2 (5): 12-18.
`
`Halsall, Fred. (1988). "Data Communication," In Computer Networks and OSI. 2nd ed. Wokingham: AddisonWesley.
`
`Schatt, Stan. (1987). Understanding Local Area Networks. Indianapolis, Indiana: Howard W. Sams.
`
`Winfield, Bob. (November 1985). "An Introduction to Local Networks," Netlink, (1) 4-6.
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