APCP: Adaptive path control protocol for efficient branch-based multicast routing in wireless sensor networks

Multicast routing is essential for various one-to-many Wireless Sensor Network (WSN) applications. While many existing multicast protocols in WSNs suffer from the overhead of the intermediate nodes' states, packet header size, computation time, and energy consumption, branch-based multicast protocol achieves an optimal trade off among problems by maintaining the membership information only on the branch nodes that are created by a bottom-up membership join from the member nodes to a source node. However, the multicast path discovered by the simple bottom-up join may incur an inefficient multicast path, and the inefficiency becomes worse as nodes further join the WSNs. In this paper, we propose an Adaptive Path Control Protocol (APCP) for efficient branch-based multicast routing in a WSN. We leverage a source initiated efficient path control approach (top-down) for building an initial branch-based multicast path. However, to overcome the expensive maintenance cost of the top-down approach, the APCP adaptively runs the top-down and bottom-up join schemes using a formula to measure the multicast path quality and overhead, named the Branch Quality Factor (BQF). Our evaluation results show that the proposed APCP reduces a multicast path length by 20% less than the existing bottom-up join schemes with 10 times lower overhead than using only top-down join that builds up the most efficient multicast path.