Evitando regiões de buraco de roteamento em redes de sensores sem fio

Abstract

The occurrence of hole regions in Wireless Sensor Networks is a significant challenge to overcome because it affects the use of geographic routing protocols regarding the transmission of messages through the network. Holes are usually associated with regions where nodes are unable to forward its information received. Its occurrence can be caused by physical obstacles, energy depletion, communication failures between neighbors elected, incorrect implantation and due to the local minimum phenomenon. Most of the solutions used to deal with the hole region problem prefer to abandon the traditional greedy forwarding mechanism to temporarily adopt the perimeter routing scheme applied to nearby nodes or along the edge of a hole. However, this strategy requires that all nodes know their location in the sensing grid, which is not always possible in forest scenarios. Also, this type of approach imposes excessive traffic to the edge nodes of the hole and its neighbors a leap away, making them increasingly used when it is intended to route packets out of the region of holes.

In this thesis proposal, we propose four (04) geographic routing solutions to deal with the problem of routing holes in Wireless Sensor Networks. The ARESTA, REACT, LRS, and BYPATH algorithms are designed to be able to create valid paths between the source and destination of the packets without using virtual coordinates, global positioning systems (GPS), or any other coordinate system that usually generates additional energy costs and are not always available. Our algorithms take advantage out of the communication range of the sink, equipped with a communication device of a higher power, in such a way that in a single jump all the nodes of the network are reached. The return of the sensor nodes to the node is done through multiple jumps using our proposed approach that uses the RSSI (Received Signal Strength Indicator) values to calculate the next hop toward the node sink, figure the wait time for sending multiple hop packets, and still enable data aggregation while diverting routing holes during the routing process. Our hole diversion solutions are capable of generating qualified flows for the flow of packages between source and destination, maintaining advantages such as high packet delivery rates and energy savings, observed in classical geographic routing algorithms.