Browse Prior Art Database

Token Ring Distance Extension

IP.com Disclosure Number: IPCOM000039728D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Keller, HJ: AUTHOR [+2]

Abstract

This article suggests a technique for connecting a large number of stations by a token ring even if the stations are much further apart from each other than a token ring usually allows. If a large communication system comprises many stations which are arranged in clusters having a distance of several km from each other, it is not possible to directly interconnect all stations by a common token ring. The invention suggests interconnecting the stations of each cluster which are not far apart from each other by a separate token ring section and interconnecting these separate token ring sections in turn by available time division multiplex (TDM) links having a data rate much higher than the token ring data rate.

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Token Ring Distance Extension

This article suggests a technique for connecting a large number of stations by a token ring even if the stations are much further apart from each other than a token ring usually allows. If a large communication system comprises many stations which are arranged in clusters having a distance of several km from each other, it is not possible to directly interconnect all stations by a common token ring. The invention suggests interconnecting the stations of each cluster which are not far apart from each other by a separate token ring section and interconnecting these separate token ring sections in turn by available time division multiplex (TDM) links having a data rate much higher than the token ring data rate. At each cluster or center, the TDM links have a demultiplexer and a multiplexer for connecting the respective nearby token ring section and other communication equipment or lines via tributaries to the TDM links, as shown in Fig. 1. To simplify conversion at the demultiplexers/multiplexers, the following is suggested: (a) Operate the token ring sections at a data rate (e.g., 8.448 Mb/s, also used as input tributary speed) which is a submultiple of the TDM link data rate (e.g., 34.368 Mb/s) so that token ring data and data of other sources can be simply interleaved on the TDM links. (b) Use HDB3-like coding (shown in Fig. 2) as input to the TDM tributary. This enables a simple conversion from the token ring Manchester code to the...