Designing minimum Forwarding Delay scheduler for WiMax/802.16 mesh networks

WiMax/802.16 is incontestably recognized by most major telecommunication industries as the most cost-effective last-mile broadband access technology. Further more, its mesh characteristic allows it to be scalable and enables it to deliver high speed Internet Connectivity over seamless distances. Recently, industrial and academical collaborations have emerged to improve the performance (reduce the end-to-end connection´s delay, decrease the buffer size at relay nodes, encounter interference ...) of WiMax/802.16 mesh, using extensive simulation/optimization tools associated with embedded WiMax/802.16 test-bed modules. In this paper, we are concerned in Minimizing the Forwarding Delay, in WiMax/802.16 mesh centralized scheduling networks. For that matter, we have designed a centralized scheduler based on integer linear programing called MFD, with an objective of minimizing the time elapsed between the reception of data of a particular connection at a relay node, and the forwarding or transmission of the connection´s data received by that relay node. That is, our model determines the optimal slot allocation of connections that minimizes the forwarding delay of connections at all relay nodes, while encountering synchronous and asynchronous interference. Results show, that minimizing the forwarding delay leads to reduced average buffered data per node at a time slot. It also reduces the end-to-end delay per connection. Moreover, enabling power aware transmissions with our MFD scheduler, achieves better performances (less end-to-end delay per connection) when compared with the maximum coverage power transmission scheme.