In this paper, we propose a combined voice/data protocol suitable for multiple access broadcast networks that provide round robin service to the stations. Such networks are well suited to the integration of voice and data since they guarantee bounded delay and provide high utilization even for high bandwidth channels. Using one such network proposal-namely Expressnet-as a representative scheme, we examine the characteristics of the service that voice traffic experiences under the voice/data protocol. We show that the access protocol is able to utilize the channel efficiently to support a large population of voice sources while maintaining low packet delay and guaranteeing some prespecified minimum bandwidth for data traffic. In addition, we show the advantages of silence suppression, i.e., discarding speech that constitutes silent periods, and we examine the cost of overloading the network in terms of the amount of speech discarded.

Local area communications networks based on packet broadcasting techniques provide simple architectures and efficient and flexible operation. Various ring systems and CSMA contention bus systems have been in operation for several years. More recently, a number of distributed demand assignment multiple access (DAMA) schemes suitable for broadcast bus networks have emerged which provide conflict-free broadcast communications by means of various scheduling techniques. Among these schemes, the Token-Passing Bus Access method uses explicit tokens, i.e., control messages, to provide the required scheduling. Others use implicit tokens, whereby stations in the network rely on information deduced from the activity on the bus to schedule their transmissions. In this paper we present many implicit-token DAMA schemes in a unified manner grouped according to their basic access mechanisms, and compare them in terms of performance and other important attributes.

Local area communication networks based on packet broadcasting techniques provide simple architectures and flexible and efficient operation. Unidirectional broadcast systems use a unidirectional transmission medium which, due to their physical ordering on the medium, users can access according to some efficient distributed conflict-free round-robin algorithm. Two systems of this type have been presented in the literature: Expressnet and Fasnet. In this paper we briefly describe these two. We identify three different service disciplines achievable by these systems and discuss and compare the performance of each. These systems overcome some of the performance limitations of existing random-access schemes, making them particularly well suited to the high bandwidth requirements Of an integrated services digital local network.