Improvement of multi-hop packet transmission scheduling in WDM optical star networks

Efficient multi-hop scheduling algorithms for packet transmissions in WDM optical star networks

“…Because of rZ2, we improve the schedule length of the optimal single-hop scheduling [3]. Moreover, our results also improve previous results in [5,6].…”

“…In the step of logical topology construction, our objective is to minimize the number of logical topologies in order to minimize the number of tuning operations on each transmitter. The problem is called the Logical Topologies Construction (LTC) problem and the LTC problem with maximum r hop distance is called the rÀLTC problem [6]. In the FR-group network, we construct a set of logical topologies L ¼ fL 1 ; L 2 ; .…”

“…For improving the efficiency of logical topologies construction, we prevent to solve the Hamiltonian Cycle (HC) problem in [5,6] and transfer the rÀLTC problem to the Round Robin Tournament (RRT) problem with x players [8]. The RRT problem is defined as that each player plays with other players in finite rounds.…”

“…In multi-hop scheduling, packet transmissions can be sent from source nodes through some intermediated nodes to destination nodes. The schedule length of multi-hop transmissions should be shorter than that of optimal single-hop scheduling, especially with long tuning latency [5,6].…”

“…Otherwise, if x is even then the LTC-Even algorithm creates 2ðxÀ1Þ logical topologies. Although the LTC algorithm is still 2-approximation for the rÀLTC problem, we improve the limited ring topologies in [5,6] to unlimited general topologies.…”