Connection availability based protection algorithm in wireless-optical broadband access network

The hybrid Wireless-Optical Broadband Access Network (WOBAN) provides a new and promising architecture for broadband access network by combining the beneficial properties of wireless and optical access technologies. To avoid huge data loss, WOBAN needs to be designed with a high availability guarantee. The purpose of this paper is to protect the Passive Optical Network at the back-end using the backup radios in Wireless Mesh Network at the front-end. The proposed protection scheme is based on a connection availability model. First, we assigned several backup Optical Network Units (ONUs) for each primary ONU not satisfying the availability requirement of primary optical connection. Under the availability requirement of backup optical connection, each backup ONU needed to reserve the residual capacity as the backup capacity to fully protect the traffic demand of its primary ONU. Then, we selectively deployed the additional radio interfaces as the backup radios for the wireless routers in the front-end under the availability requirement of backup wireless connection, in order to establish the wireless-backup-path between each pair of primary and backup ONUs. Each backup radio on the wireless-backup-path will retain the backup radio capacity for rerouting traffic, so as to decrease the possibility of traffic block in case of failure. We aimed to design efficient heuristic algorithms and yield suboptimal solutions for minimizing the consumption of backup ONU capacity and the cost of backup radios. Simulation results demonstrate the advantage of the proposed scheme compared to previous works.