A NEW OPTICAL SIGNAL ROUTING SCHEME FOR LINEAR LIGHTWAVE NETWORKS

In this paper we propose a new scheme for optical signal routing withi n linear lightwave network (LLN) subnets. LLN is a recently proposed f iber optic network which performs only linear operations on optical si gnals: power combining, splitting and possibly linear optical amplific ation. LLN can be partitioned into several subnets where each subnet i s a tree providing full broadcast among all stations connected to it. We study the synchronization problem that exists in these subnets whic h prevents efficient implementation of time division multiple access s chemes for sharing a common broadcast medium. A solution to this probl em is proposed, based on a new optical signal routing scheme, called r ooted routing. The impact of rooted routing on power losses is analyze d, and an approach for minimizing power loss in LLN's with rooted rout ing is presented. It is shown that when link and excess losses are sma ll, rooted routing power budget can be made close to the power budget yielded by the original, shortest path routing scheme. It is also show n that rooted routing power budget can be significantly improved using a single optical amplifier.