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Randomizing Transmission Delays in a Closed Ring Environment

IP.com Disclosure Number: IPCOM000045431D
Original Publication Date: 1983-Mar-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Weiss, L: AUTHOR

Abstract

In a closed-ring peer to peer communication network, in which data processing stations communicate by circulating structured variable length information frames and response frames around a unidirectional ring, stations may be governed at the software level by a locking protocol in which a subchannel at a first station may be dedicated exclusively for reception of a multi-frame data message from a particular second station. In this configuration the first station rejects data sent to it from stations other than the second station, but subsequently "broadcasts" a "not busy" control frame (i.e., a frame addressed to all other stations) when its locked mode reception is completed.

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Randomizing Transmission Delays in a Closed Ring Environment

In a closed-ring peer to peer communication network, in which data processing stations communicate by circulating structured variable length information frames and response frames around a unidirectional ring, stations may be governed at the software level by a locking protocol in which a subchannel at a first station may be dedicated exclusively for reception of a multi- frame data message from a particular second station. In this configuration the first station rejects data sent to it from stations other than the second station, but subsequently "broadcasts" a "not busy" control frame (i.e., a frame addressed to all other stations) when its locked mode reception is completed.

In order to avoid a potential deadlock, stations receiving the "not busy" frame, and desiring to send data to the first station, evoke preassigned time-out delays of different deviations before attempting respective data transmissions. These delays are characterized by: D=NK, where D is the delay time in seconds, N is a random number from 0 through 7, and K is a constant equal to: number of bytes in a maximum length frame X 1.1/ ring data rate in bytes.

Invocation of this algorithm effectively randomizes the timing of transmissions from stations which may be in contention, and significantly reduces the number of re-attempted transmissions required of such stations (thereby reducing the inefficient use of ring bandwidth for repeat...