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Browse Prior Art Database

Circuit Switching Shared Media Hybrid

IP.com Disclosure Number: IPCOM000043984D
Original Publication Date: 1984-Oct-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 3 page(s) / 26K

Publishing Venue

IBM

Related People

Jaffe, JM: AUTHOR [+3]

Abstract

Many system organizations include communications between both people and computers. Both of these have a need to communicate electronically. People typically communicate by voice transmission over a phone through a PBX. Local computers generally communicate over coax attached hierarchically to HOST systems. This has the disadvantages of limiting system to system connectivity and requiring a separately managed set of wires and network management structure for computers and phones. The connectivity problem is being addressed by shared media, packet switched local area networks (LANs), but this is not solving the costly requirement of having two separate systems.

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Circuit Switching Shared Media Hybrid

Many system organizations include communications between both people and computers. Both of these have a need to communicate electronically. People typically communicate by voice transmission over a phone through a PBX. Local computers generally communicate over coax attached hierarchically to HOST systems. This has the disadvantages of limiting system to system connectivity and requiring a separately managed set of wires and network management structure for computers and phones. The connectivity problem is being addressed by shared media, packet switched local area networks (LANs), but this is not solving the costly requirement of having two separate systems. Historically, the reason for this distinction is that voice conversations are "continuous" in nature, and can tolerate no degradation (other than a busy signal) during times of overload, and computer communication requires higher burst bandwidth, but on the average requires less total bandwidth. Circuit switched PBX's have increasingly higher aggregate bandwidth, and individual connections have increasingly higher bandwidth as well. Generally speaking, this factor is allowing modern PBXs to integrate a small quantity of data. The total quantity of data that can be transmitted on the PBX tends to be limited by two factors. First, each data conversation uses up a dedicated circuit from a PBX. If this would be a high bandwidth circuit capable of handling the burst high bandwidth required by the computers, this would quickly eat up the entire bandwidth of the PBX. On the other hand, low bandwidth circuits do not really meet the requirements of data transmission. The second problem is that certain large systems must communicate with many other systems. It would be inconvenient to tie as many lines to that system as would be required to support all potential users (easily in the hundreds or thousands). The system described uses a single, simple idea to simultaneously solve both of the above problems. The idea is to allow multiple machines to access a single circuit as a conference call and then manage this call as a shared media. This circuit would be a high bandwidth circuit as is becoming available from new PBXs and will be more prevalent in the future. This solves the problem of using too much bandwidth with high speed circuits as the bandwidth would be shared. It also solves the problem of the high burst requirement as there is reasonably high bandwidth available on the circuit. Finally, it alleviates the problem of multiple circuits to the large system, by multiplexing many users on a single circuit. This circuit is seen by the PBX as a single PBX call, and thus does not use up too much of the PBX bandwidth to allow these multiple conversations. This idea is similar to voice conference calling, but its use in this context is quite different. Usually, in space division PBXs, a conference call of n users must use up n voice slots. If naivel...