A MAC protocol for an ATM PON supporting explicit rate congestion control for ABR traffic

This paper presents and evaluates the performance of a MAC protocol for a broadband access network using an ATM passive optical network (PON) supporting different service categories. The protocol is an enhancement of an earlier version proposed by the authors and implemented in the demonstrator of a project in the European RACE programme. A request/permit mechanism controls the access to the shared medium. The bandwidth allocation algorithm gives priority to the CBR/VBR traffic and ensures a minimum cell rate for the ABR traffic. The unused bandwidth is allocated to UBR traffic.