A simplified optical star network using distributed channel controllers

In the paper, a new network architecture is presented for single-hop passive optical star networks. The objective is to simplify the user stations as much as possible, thus giving an economical design. This is accomplished by using a set of distributed channel controllers, one for each WDM channel. The network will thus be referred to as DCCN (for distributed channel controller network). The channel controllers assist in the operation of the network in a number of ways. In the network, the allocation of bandwidth is hierarchical and is achieved independently on each channel. This simplification decouples system operation into two levels. At the higher level, bandwidth partitioning may be done in a static or dynamic fashion. The lower level determines the dynamic use of slots. Two options for media access are proposed. The first is a centralized approach based upon an “asynchronous request switch” design. The second is much more distributed. Each set of competing stations builds a distributed queue based upon observed requests. Capacity results are presented for the design and compared with other protocols. It is found that the proposed architecture has much higher capacity than in many other networks with similar hardware requirements