Improved TDM Transmission Frame Construction

Abstract

In the previous chapter, a greedy algorithm has been developed for solving the TDM transmission frame construction problem in a U-PSR network. The resulting algorithm (S-R/I-WTA) is based on the simplifying assumption that the routing subproblem is solved separately from the wavelength assignment and time-slot assignment subproblems. This assumption may not lead to the best possible performance. For example, if some fiber link is shared by the route of many connections, a long transmission frame length is needed to accommodate all connections. If, on the other hand, the routes of the connections would be assigned in such a way that the number of connections per link is more equalized across the network, a shorter frame length may be achievable. In this chapter, we will develop a solution that reconsiders the route, as well as wavelength and time slot, for the candidate connections during each stage of the TDM transmission frame construction process. In other words, the algorithm solves the three subproblems in an integrated fashion.