A loss-tolerant stateless tree routing protocol for IP-based wireless sensor networks

Abstract

The IP-based Wireless Sensor Network (IP-WSN) is one of the essential elements enabling Internet of Things. However, IP-WSN imposes great challenges due to low processing resources and strict energy constraints of sensor nodes, so that it is important to design the routing protocol considering those challenges. The plain tree routing protocols are proposed considering low-cost communication with resource-constraint and typical traffic patterns like multipoint-to-point (MP2P) or point-to-multipoint (P2MP), but those routing protocols incur triangular detour routes as far as point- to-point (P2P) traffic is concerned. Other tree routing protocols are also proposed to improve the efficiency of P2P route. Although they can improve the efficiency of P2P route compared the plain tree routing protocols, they are yet to define the link recovery mechanism. The link recovery mechanism is indispensable to the tree routing protocols, because the wireless links are repeatedly connected and failed, and they are important for delivering successfully a packet to the destination. To address those issues of the existing tree routing protocols, we propose a Loss-Tolerant Stateless Tree Routing protocol (LTSTR). LTSTR defines a novel link recovery mechanism unlike existing tree routing protocols. If the link loss is detected, this mechanism provides the method to avoid the failed links by using the fault-avoidance routing and the lightweight source routing. LTSTR also provides the reduced hop route in terms of P2P traffic as well as typical traffics through the enhanced shortcut tree routing (ESTR) algorithm and the root oriented directional tree (RODT) topology. ESTR algorithm enables a packet to be forwarded to the node having the smallest remaining hop count among neighbors instead of always forwarding a packet through the predefined tree routes, and LTSTR guarantees the shortest hop route toward the root by RODT topology. Additionally, LTSTR provides a nearly stateless rout...