## 1 Introduction  
Access networks are the last mile of the communication networks that connect the telecommunication central office (CO) to the residential or business users. Conventionally, access networks are implemented by optical technologies such as passive optical networks and wireless networks such as wireless mesh networks. While optical networks enable high-bandwidth and long distance communications, wireless technologies are used for flexibility and low bandwidth uses. However, the current trend of Internet usage involves rapid growth of users [1], growing demands for bandwidth-intensive services, as well as the desire for flexibility (anytime-anywhere service). These complex set of requirements are accelerating the research on efficient and cost-effective access infrastructures where optical-wireless combinations are seen as a promising approach. The wireless-optical broadband-access network (WOBAN) is a novel hybrid access network paradigm with the combination of high-capacity optical backhaul and highly flexible wireless front-end that can provide higher bandwidth in a cost effective manner. In WOBAN architecture, optical fibers are provided as far as possible from the CO to the end users and wireless access is provided in the front end. Because of its excellent compromise, this WOBAN architecture enjoys low deployment costs because of lower fiber costs than traditional passive optical networks. A WOBAN consists of a _passive optical networks (PON)_ at the back end and a multi-hop wireless mesh networks at the front end. At the back end, _optical line terminal (OLT)_ resides in the CO and feed to multiple _optical network units (ONUs)_ through a traditional fiber network. Each ONU is connected to one or more wireless gateway(s) that provide the interface to a wireless mesh network comprising the wireless front end. Thus, if a mesh router needs to send a packet to the Internet, it has to send it to any one of the gateways, which is then forwarded through the optical part of the WOBAN. Since the bottleneck of communication performance, such as throughput and delay, is largely on the wireless mesh network component of the hybrid network, it is of interest to design mechanisms to maximize the throughput performance of anycasting between the wireless routers and any one of the available gateways in a WOBAN. Co-channel interference is the main factor that reduces the network throughput in the wireless networks. To cope for this, the IEEE 802.11 standards provide multiple non-overlapping frequency channels to support multiple simultaneous transmissions in the same interference region. For example, IEEE 802.11b/g offers three non-overlapping 20 MHz channels, while IEEE 802.11a offers 24 non-overlapping 20 MHz channels and 12 non-overlapping 40 MHz channels. IEEE 802.11n and 802.11 ac also provide multiple non-overlapping channels of different bandwidths. Table 1 summarizes major IEEE 802.11 standards and their available non-overlapping channels. By exploiting the advantages of multiple channels and multiple radios, the system performance of mesh networks can be improved significantly compared to the single-channel wireless access networks [2]. However, all of these benefits can only be achieved by applying a carefully designed channel assignment scheme so as to utilize these multiple channels and radios effectively. Moreover, since co-channel interference at a node is determined by the assignments of channels to the neighboring nodes as well as their traffic patterns, the solution to this problem involves channel assignment as well as routing. Our interest is to develop a _holistic_ solution that addresses the channel assignment and anycast-routing problems together for maximizing the throughput performance in the wireless mesh.