Semi-Beaconless Power and Cost Efficient Georouting with Guaranteed Delivery using Variable Transmission Radii for Wireless Sensor Networks

We assume that sensors are aware of the positions of neighbors within a specific knowledge range, which is smaller than their maximum transmission range. We propose the GRoVar protocol (Geographic Routing with Variable transmission range) that extends the well-known GFG protocol [2], a combination of greedy forwarding and recovery, by applying variable transmission range and beaconless routing techniques. In our protocol, each node locally selects the best forwarding neighbor within its knowledge range, using power or other metric. If no neighbor is closer to the destination, the current node may incrementally increase its transmission range to find suitable candidates for the next hop, with the help of request messages. Face routing is applied when no forwarding neighbor is found after sending requests with the maximum transmission range. It also applies range increases until recovery is possible. We investigated different possibilities: a linear increase, doubling the range in each iteration or directly jumping to the maximum range possible. The comparison of energy usage for data transfer from source to sink shows that a significant saving in energy consumption can be achieved using the proposed method.