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Voice, Video and Data Integration Hybrid Mechanism

IP.com Disclosure Number: IPCOM000060910D
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Lien, YC: AUTHOR [+3]

Abstract

This article describes a technique for permitting synchronous and asynchronous data traffic to cohabitate on a single communications channel. In essence, the presence of synchronous data causes the channel to change from a packet switching configuration (Fig. 1) to a subchannelized, TDM configuration with a frame of subchannels (Fig. 2) flowing in each time period. Synchronous data is transmitted in the subchannels. The line or communications channel is used for queued data until a real-time conversation needs service. For the duration of the transmission of the queued data the line is used in an optimum fashion directly comparable to conventional packet switching protocol (Fig. 1).

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Voice, Video and Data Integration Hybrid Mechanism

This article describes a technique for permitting synchronous and asynchronous data traffic to cohabitate on a single communications channel. In essence, the presence of synchronous data causes the channel to change from a packet switching configuration (Fig. 1) to a subchannelized, TDM configuration with a frame of subchannels (Fig. 2) flowing in each time period. Synchronous data is transmitted in the subchannels. The line or communications channel is used for queued data until a real-time conversation needs service. For the duration of the transmission of the queued data the line is used in an optimum fashion directly comparable to conventional packet switching protocol (Fig. 1). Immediately upon receipt of the real-time request the line is preempted and redefined as a subchannelized TDM line with a frame of subchannels flowing each time period (Figs. 2A-2D). The reconfiguration guarantees delivery and minimum delay of the real-time conversation(s). The preemption is caused by the appearance on the line of a delimiter which may take one of several forms including an SDLC (Synchronous Data Link Control) flag, a different (that is, non-SDLC) flag, an electrical transmission violation, or a code violation. Initially, the voice packet (containing a talkspurt) is sent on the first fixed-width subchannel. This results in an optimum utilization of the line but now, in addition, the real-time small delay requirement is also satisfied. When the talkspurt ends, then the subchannel collapses and the non-fixed-width subchannel increases to resume the fixed- width subchannel data rate....