ATM Forum defines five service catetories which relate traffic characteristics and QoS(Quality of Service) requirements to network behaviour. Current ABR service with explicit rate congestion control and minimum cell rate guarantee provides such a powerful service option that it may well be more effective for MPEG transmission than the CBR/VBR service currently defined for real time use. MPEG transmission requires guarantee of MCR over several Mbps and limited cell delay jitter.
In this thesis, we propose a rate-based congestion control scheme, called ERISM(Explicit Rate Indication Scheme for MPEG), which guarantees non-trivial MCR and avoids over-allocation. For the guarantee of non-trivial MCR, we develop a rate allocation algorithm which supports a connection with MCR over several Mbps by defining a new VC state, called critically bottlenecked. For the avoidance of over-allocation, we define a new field, AR in RM cell. AR/ER fields prevent the sum of newly allocated bandwidth and bandwidth allocated to other connections from exceeding link capacity.
The performance of ERISM is evaluated in terms of avoidance of over-allocation, guarantee of non-trivial MCR, VBR traffic effects, and burst transmission. Results from simulations using three greedy ABR source, one VBR source with ON/OFF model and one bursy source shows that ERISM supports the connection with MCR larger than fairshare well, keeps the queue length being minimal, and has a good burst transmission capability. The evaluation of service quality on MPEG transmission with real video traces over ERISM has to be evaluated further.
