A compatible fixed-frame ISDN gateway for broadband metropolitan area networks

A novel method (referred to as I-SWIFT) is presented for integrating the flow of synchronous voice streams into existing broadband cable systems using CATV (community antenna television) technology. 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. An intelligent scheduling algorithm in the MAG dynamically allocates channel bandwidth using a variation of the data-switch-filtering techniques first introduced by T. D. Todd (1987). The MAG accomplishes this by establishing a fixed voice frame (with realignment) which is implemented in an upwardly compatible fashion with respect to the existing CSMA/CD (carrier-sense multiple access with collision detection) data stations. Thus, previously installed stations require no modification. Results are presented which indicate that I-SWIFT performs significantly better than previous compatible voice/data integration methods.<>