The spiral ring

We present a new topology for high-speed ring networks: the spiral ring. We also describe a mac{level protocol, called Distributed Spiral Multiple Access (dsma), suitable for the spiral ring topology. The dsma protocol is based on token passing and gives a fair and eecient network behaviour regardless of the transmission rate and network size. Under light load, the medium access delay approaches zero. When the load is heavy, the medium access delay is bounded, guaranteeing that starvation will not occur. The proposed protocol is able to handle synchronous traac of varying intensity. Unlike other network protocols, it does not require any bandwidth pre-allocation for the synchronous part of the traac. Another property of dsma protocols is a provision for a graceful dynamic reconnguration (station insertion/deletion) and costless protocol recovery after a lost token.