# Minimum Interference Channel Assignment Algorithm for Multicast in a Wireless Mesh Network
## 2 Related Work
Additionally, node A is within node B's transmission range in Figure 1. Unfortunately, node B uses the same channel as the source node's sending interface. If nodes S and B transmit their packets at the same time, there will be a collision at node A. This situation occurs because node B examines only the channel assigned to its one-hop neighbor A and does not consider the one assigned to two-hop neighbor S. Our new channel assignment algorithm thinks about every pair of nodes within the given network in order to minimize network interference and improve overall network throughput. Figure 1: An example of channel assignment by MCM. [PERSON] et al. [15] provided a channel assignment algorithm named minimum interference multi-channel multi-radio multicast (M4). M4 allows nodes to broadcast the channel information to their neighbors whenever every node receives the broadcast message, it adds its own channel information and re-broadcasts the updated message to its neighbors. The M4 algorithm has definitely improved performance compared to MCM. It considers not only one-hop neighbors but also two-hop ones for channel assignment to solve HCP. However, if the physical distance of one node and its two-hop neighbors is close, there may be network interference between the two nodes. Therefore, M4 still has a network interference problem. Due to this reason, our proposed algorithm investigates every pair of nodes in the multicast tree to minimize network interference. [PERSON] et al. [18] proposed a layered binary integer programming (layered BIP)-based solution for the channel assignment in WMNs. The primary goal of layered BIP is to minimize the total number of links in the multicast tree and network interference. One drawback of the study is that there is no large difference to deal with multicast communication compared to unicast communication. In [19], authors also adopted an integer linear programming in order to minimize the carried load on the most-heavily loaded channel and maximize the residual capacity of the most heavily loaded node. They proposed a heuristic multicast tree construction and channel assignment algorithm called largest coverage and shortest path first (LC-SPF). MCM and M4 mainly concentrate on minimizing network interference between nodes in order to increase network throughput and mitigate end-to-end packet delay. However, [PERSON] et al. [20] proposed the load-based MCM (LMCM). This scheme selects a relay node based on the largest load value when it constructs a multicast tree. In this study, load means the number of subscribers served by the sub-tree rooted at the node. In addition, two channel assignment mechanisms are also proposed in the paper-load-based depth first search and load-based breadth first search. [PERSON] et al. [21] proposed a heuristic channel assignment algorithm named progressive channel assignment (progressive CA). In progressive CA, channel assignment is decided according to a certain acceptable threshold value. The algorithm visits each node in the multicast tree using a breadth-first search to find the highest interference factor below the threshold. However, there is no mention about how to decide the threshold in the paper.