A Flow-aware MAC Protocol for Passive Optical Metropolitan Area Network

Abstract. The paper introduces an original MAC protocol for a passive op-tical metropolitan area network using time-domain wavelength interleaved net-working (TWIN). Optical channels are shared under the distributed control of destinations using a packet-based polling algorithm. This MAC is inspired more by EPON dynamic bandwidth allocation than the slotted, GPON-like ac-cess control generally envisaged for TWIN. Management of source-destination traffic streams is flow-aware with the size of allocated time slices being propor-tional to the number of active flows. This emulates a network-wide, distributed fair queuing scheduler, bringing the well-known implicit service differentiation and robustness advantages of this mechanism to the metro area network. The paper presents a comprehensive performance evaluation based on analytical modelling supported by simulations. The proposed MAC is shown to have excellent performance in terms of both traffic capacity and packet latency. 1