A compatible ISDN gateway for broadband metropolitan area networks

A novel gateway design (referred to as T-SWIFT) is presented for integrating the flow of voice streams into existing broadband cable systems. The interface between the integrated voice subnetwork and the cable system is realized by a metropolitan area gateway (MAG) which is implemented at the broadband cable head-end. In T-SWIFT, an intelligent scheduling algorithm in the MAG dynamically allocates channel bandwidth using a variation of the data switch-filtering and fixed-frame synchronous voice/data integration techniques introduced by the author (see IEEE J. Selected Areas in Commun. vol., SAC-5, no.9, p.1391-1402 (1987)). The MAG accomplishes this by coordinating the transmission of inbound and outbound voice talkspurts in an upwardly compatible fashion with respect to the existing CSMA/CD data stations. Thus previously installed stations require no modification. Results are presented which indicate that the T-SWIFT design performs significantly better than previous compatible voice/data integration methods