  Due to the high demand of Internet access by users, and the tremendous
success of wireless technologies, Wireless Mesh Networks (WMNs) have become a
promising solution. IGW Placement and Selection (GPS) are significantly
investigated problems to achieve QoS requirements, network performance, and
reduce deployment cost in WMNs. Best effort is made to classify different works
in the literature based on network characteristics. At first, one of the most
principal capabilities of WMNs, which is taking advantage of using multi-radio
routers in a multi-channel network, is studied. In this article, GPS protocols
considering a definition of three types of WMN are investigated based on
channel-radio association including Single Radio Single Channel (SRSC), Single
Radio Multi- Channel (SRMC), and Multi-Radio Multi-Channel (MRMC) WMNs.
Furthermore, a classification regarding static and dynamic channel allocation
policies is derived. In addition, the reported works from the viewpoint of
network solutions are classified. The first perspective is: centralized,
distributed or hybrid architectures. Following this classification, the studies
are categorized regarding optimization techniques, which are operation
research-based solutions, heuristic algorithms, and meta-heuristic-based
algorithms.
