Resource Optimization Scheme for Multimedia-Enabled Wireless Mesh Networks

Amjad Ali, Muhammad Ahmed, Md. Piran, Doug Suh
2014 Sensors  
Wireless mesh networking is a promising technology that can support numerous multimedia applications. Multimedia applications have stringent quality of service (QoS) requirements, i.e., bandwidth, delay, jitter, and packet loss ratio. Enabling such QoS-demanding applications over wireless mesh networks (WMNs) require QoS provisioning routing protocols that lead to the network resource underutilization problem. Moreover, random topology deployment leads to have some unused network resources.
more » ... efore, resource optimization is one of the most critical design issues in multi-hop, multi-radio WMNs enabled with multimedia applications. Resource optimization has been studied extensively in the literature for wireless Ad Hoc and sensor networks, but existing studies have not considered resource underutilization issues caused by QoS provisioning routing and random topology deployment. Finding a QoS-provisioned path in wireless mesh networks is an NP complete problem. In this paper, we propose a novel Integer Linear Programming (ILP) optimization model to reconstruct the optimal connected mesh backbone topology with a minimum number of links and relay nodes which satisfies the given end-to-end QoS demands for multimedia traffic and identification of extra resources, while maintaining redundancy. We further propose a polynomial time heuristic algorithm called Link and Node Removal Considering Residual Capacity and Traffic Demands (LNR-RCTD). Simulation studies prove that our heuristic algorithm provides near-optimal results and saves about 20% of resources from being wasted by QoS provisioning routing and random topology deployment. OPEN ACCESS Sensors 2014, 14 14501 Keywords: ILP; wireless mesh networks; random topology; QoS provisioning routing; heuristic algorithm Routing protocols can be categorized into two major classes in the context of the types of applications and services they support: (1) QoS provisioning routing that enables multimedia and other QoS demanding applications; (2) conventional routing that enables non-real time and multimedia applications. These two different types of routing can cause two different network problems in their respective fields of application. Conventional routing induces resource overutilization problems [9] [10] [11] . In resource overutilization, many traffic flows share the same network resources (e.g., router buffer and data channel), which may cause network congestion that reduces the overall network throughput. Designing QoS provisioning routing protocols that enable multimedia and QoS-demanding applications and services is an emerging field of research. Currently available QoS provisioning routing protocols follow a self-serving approach to find and select an end-to-end routing path that fulfills the QoS requirements of multimedia applications [12] .Therefore, in QoS provisioning routing bandwidths, delays, and Packet Loss Ratio (PLR) are not only the multimedia application requirements, but they are also being used as default routing parameters [13] . Moreover, link quality metrics e.g., Expected Transmission Count (ETX), per-hop Round Trip Time (RTT), and per-hop Packet Pair delay (PktPair) are a few better known greedy parameters that also used in QoS provisioning routing. QoS provisioning routing protocols that are based on stated parameters adopt greedy selection mechanisms and create a network resource underutilization problem. In a resource underutilization problem, abundant multimedia traffic flows follows distinct routing paths and network resources (e.g., router buffer, data channel) over those routing paths may not be shared by other multimedia traffic flows. Thus, the allocated bandwidth will not be effectively utilized, which causes a resource wastage problem and results in high network deployment costs. Network congestion in wireless and mesh networks has been studied extensively in the literature [14] [15] [16] [17] , however to the best of our knowledge QoS provisioning routing-based resource underutilization has not been addressed. The ideal deployment of WMNs requires conducting detailed site surveys to find the appropriate locations before the actual placement of the Wireless Mesh Routers (WMRs) and communication links. This practice is usually followed in academic test beds, but the practical deployment of WMNs is usually unplanned or random [18, 19] . This makes them easy to deploy and reduces the network administration time, but may lead to the installation of unused physical layer resources (e.g., WMRs, communication links) that cause high deployment and operating costs. For example, if a WMR never routes through one of its neighbors, then that neighbor's link is questionable [20] . For example, if most WMRs are routed through only one or two neighbors, then it might be worth keeping only those neighbors. Although redundancy is one of the core design factors in WMNs, redundancy beyond a specific threshold wastes resources and increases the deployment and operating costs. Moreover, with the increasing bandwidth demands and the scarcity of available frequency spectrum, designing resource-efficient wireless mesh networks is a new challenge [21] . Thus, supporting multimedia applications and services by using minimum physical layer resources with overall low ownership cost is a challenge task. To the best of our knowledge, the resource wastage problem caused by QoS provisioned routing and random deployment of WMNs have not been studied in the literature, hence, it is addressed for the first time in this paper. Our objective is to reconstruct the optimal connected mesh backbone topology with the minimum number of communication links and WMRs that satisfy the given end-to-end QoS demands for multimedia traffic and the identification of extra resources while
doi:10.3390/s140814500 pmid:25111241 pmcid:PMC4179066 fatcat:fpuwmkauxnga5lmic3brtstt6m