Metaring--A full-duplex ring with fairness and spatial reuse

Abstract

The design principles of a ring network with spatial reuse are described. The goal is to provide the same functions as designs that do not permit spatial reuse and concurrent transmission. A distributed fairness mechanism for this architecture is presented. The basic fairness mechanism can be extended for implementing multiple priority levels and integrating asynchronous with synchronous traffic. The ring is full-duplex and has two basic modes of operation: a buffer insertion mode for variable-size packets and a slotted mode for fixed-size packets. As a result, this architecture is suitable for a wide range of applications and environments. Concurrent access and spatial reuse permit simultaneous transmissions over disjoint segments of a bidirectional ring and, therefore, can increase the effective throughput by a factor of four or more. The efficiency of this architecture does not degrade as the bandwidth and physical size of the system increase. The combination of a full-duplex ring, spatial reuse, a reliable fairness mechanism, and the exploitation of recent advances in fiber-optic technology are the basis for the Metaring network architecture.