This paper describes and evaluates variations of a generic hybrid switching concept for integrated voice and data communications. Concepts examined include the Slotted Envelope NETwork approach, the enhanced hybrid (SENET) with time assignment hybrid, and the variable length frame/packet approach. Primary criteria used to evaluate the concepts are transmission throughput efficiency and delay versus information throughput. Other criteria, such as voice continuity and routing/flow control, were also applied.

A new multiple access scheme is proposed and evaluated. The proposed scheme combines desirable features of the ordinary time-division (TDMA) and the random access (RA) schemes. It is shown that by adjusting the value of a single parameter a, the proposed access method can vary continuously from one extreme (TDMA) to the other (RA). The average delay per packet and the throughput can be improved for intermediate values of the load factor. Furthermore, the method can control the channel instability.

Virtual circuit and pure packet (datagram) based switching techniques are studied for future application to the integrated voice/data telecommunications. The coexistence of voice with both interactive and bulk data in an integrated network suggests the desirability of a mixed switching technique to allow the efficient sharing of both the switching and communications resources. Such a mixed packet switching scheme is also evaluated. It uses virtual circuit for regular traffic (voice and bulk data), and uses pure packet (datagram) for bursty traffic (interactive and query/response). It also adapts to changes in voice/ data input traffic mixture.