GENERALIZED ACCESS-CONTROL STRATEGIES FOR INTEGRATED SERVICES TOKEN PASSING SYSTEMS

The demand for integrated services local area networks is increasing a t a rapid pace with the advent of many new and exciting applications: office and factory automation, distributed computing, and multimedia c ommunications. To support these new applications, it is imperative to integrate traffic with diverse statistical characteristics and differi ng delay requirements on the same network. An attractive approach for integrating traffic has been adopted in two token passing local area n etwork standards, the IEEE 802.4 token bus standard [1] and FDDI [2]. The idea is to control the transmissions of each station based on a di stributed timing algorithm, so as to achieve the following goals: (i) to limit the token cycles so that time-critical traffic can be accommo dated, and (ii) to allocate pre-specified bandwidths to different stat ions when the network is overloaded. We have investigated the analysis and design of this protocol in [3]. In this paper, we generalize the transmission control algorithm used in [1]-[2]. The major advantages o f the generalization over the original protocol are: (i) it provides a much expanded design space, (ii) it guarantees convergent behavior, a nd (iii) it gives meaningful insights into the dynamics of the basic c ontrol algorithm.