Delay Reduction in Hybrid Wireless Optical Broadband Access Network

Abstract

The hybrid wireless-optical broadband-access network (WOBAN) is a promising architecture for future access networks. The front end is wireless network and the back end is optical network. Recently, the wireless part of WOBAN has been gaining increasing attention due to number of challenges. However, there still remain several challenges which need to be addressed. One of the major challenges identified is network delay. Capacity mismatch between the optical and the wireless network and congestion are the reasons for delay. A number of routing protocols are proposed to address the problem of delay in wireless part of WOBAN. The routing protocols which are proposed so far are either reactive or proactive. All the protocols are designed on some routing metric like minimum hop, throughput requirement and capacity etc. We also outlined the problem of delay minimization in WMN. We proposed a hybrid routing algorithm combining the features of reactive and proactive routing approaches for reducing end to end delay. In our proposed approach, network is divided into zones and each node has its own zone. RARA is used between the zones and CADAR is used inside the zones. Capacity and delay are calculated for each zone and minimum delay paths inside all the zones is calculated for efficient. The simulation results show that our proposed algorithm, when compared with RARA and CADAR, is able to minimize delay especially at higher load regions. Moreover, due to the hybrid nature of algorithm, the overhead of maintaining routing tables and control packets is also decreased. As a future work, it can be interesting to consider a real network scenario. Furthermore, in this work, we considered static topology; it is worth to test the proposed algorithm on a dynamic scenario.