A Study on Various Hierarchical Routing Structures Supporting Mobility Assisted WSN

Hierarchical routing outperforms other routing techniques, but has one major issue: hotspots near sink nodes, i.e., nodes near sink nodes, deplete the battery more rapidly. The mobile sink addresses this problem well. As the mobile sink moves through the network, the hotspot around it also moves, resulting in load balancing throughout the network. However, various overheads are associated with mobile sinks, such as location advertisement, pathfinding, etc. This paper discusses different structures related to hierarchical routing that support sink mobility. Various design constraints and issues associated with mobile sinks are discussed. In the end, various routing protocols are summarized according to sink mobility pattern, position awareness, multi-sink support, protocol overhead, etc. The achievements and limitations of each protocol are also discussed.