Edwin B. Brownrigg

A Packet Radio Network for Library Automation

The progress of libraries towards establishing online databases and automated search and retrieval tools allows them to share their resources and provide access to remote users. Unfortunately, the steady increase in the cost of leased lines makes them very undesirable as the media for access networks for budget-constrained libraries. An alternative approach-a packet switching radio network-is therefore presented here. Low-cost, commercially available radio transceivers and standard personal computers are the hardware building blocks of the system. The resulting network employs a suite of protocols, including channel access, routing, congestion control, and the higher-level TCP/IP. This network, which is planned to cover a large part of northern California, will provide remote access to University of Californias automated library online catalog system. It will also support communication between any two end-points, provide for alternative routes in cases of link or nodal failure, and monitor its own performance. This paper, then, presents the networks topology, its architecture, its basic elements, and the functions it performs.

Publishing Bibliographic Data On Optical Disks: A Prototypical Application And Its Implications

Bibliographic databases are quite large and relatively static, making them ideally suited for storage on optical media now becoming available. Consequently, libraries and publishing houses are pioneering certain applications of optical disks. The high storage density and the economy of optical disks make them attractive media for large databases. However, two factors create problems in the design of sophisticated retrieval software: certain device characteristics (e.g., slow access time compared to magnetic media), and the user interface requirements for bibliographic data. We discuss a prototypical application of optical disks to the publishing of the Library of Congresss machine-readable collection (the MARC and REMARC databases). The prototype disk is manufactured from pre-mastered videotape and is controlled by an IBM PC microcomputer. The prototype represents a significant effort in system integration, requiring development of hardware interface, error correction, low-level access software, high-level language interface, and user-friendly front-end applications. To prepare the data for indexing and display, mainframe software was developed. Based on our experience with the prototype, we discuss a number of issues common to the publication of such databases: data structures, search strategies, precomputation of retrieval results (a powerful technique well-suited to optical disk applications), and issues pertaining to standardization and publication formats.