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Top1. Introduction
Wireless Mesh Networks (WMNs) have emerged as a promising technology, due to its potential of offering a wireless backhaul service with high bandwidth and minimum cost to mobile clients. The WMN contains the wireless mesh routers, the mobile clients, and the gateways. The wireless mesh routers have low mobility compared to mobile clients, forming the mesh backbone (Akyildiz, 2005; Bruno & Gregori, 2005). In the presence of minimal mobility clients, the dynamic changes in the network topology are lesser. However, achieving high throughput in routing is a challenging problem due to the highly utilized shortest paths, even under a stable network topology. As a consequence, the focus on the metric of the routing layer for designing the multicasting service in WMN has to be varied from the selection of the shortest path to the high-quality path. Towards this objective, more complicated services have been proposed with new routing metrics (Awerbuch, 2006; De Couto, 2005; Draves, 2004). In most of the cases, unicast routing protocols are proposed and analyzed for all these services in WMNs (Perkins 2003).
Multicasting is another key technology for supporting a model where one source distributes the same data to multiple receivers. Multicast streaming supports the wireless mesh in collaborative applications such as video streaming broadcast, for example, a live streaming of a cricket match and an IP radio broadcast (Jahanshahi, 2014). The most popular Internet applications for multicasting such as Internet Protocol Television (IPTV) that allows users to watch the TV programs anytime anywhere are Bit Torrent, and YouTube. Video broadcasting is not only expensive in terms of bandwidth and server storage, and also has to scale with a huge number of users, for example, 65% of viewers watch TV programs daily. YouTube spends $1,000,000 a day for its server bandwidth since more than 1 billion viewers has visited YouTube each month (http://www.youtube.com/yt/press/statistics.html). The live streaming of multimedia in TV or YouTube needs to play instantly without buffering delay. Thus, the prime requirement of multicast streaming applications is QoS in terms of throughput, delay, and high bandwidth. The existing multicasting protocols have taken into account the routing layer metric such as hop count for selecting the routing paths to multicast receivers (Jetcheva, 2001; Kumar, 2012).However; it does not meet the application requirements such as throughput and delay, due to the absence of link quality measurement. It is important to handle the issues related to the QoS routing to support high bandwidth, throughput, and delay constraints (Nguyen, 2007).