Controlling the Transmission Power

This chapter describes the most important topology construction algorithms and protocols that build the reduced topology by controlling the transmission power of the nodes. First, we consider the case where all nodes in the network are similar, i.e., assuming an homogeneous infrastructure. Here, we have centralized algorithms and distributed protocols. Controlling the transmission power in a centralized manner is perhaps the most mature topology construction technique. Under this approach there are two well-known problems: The Critical Transmission Range (CTR) problem, which finds the minimal communication range for all the nodes in the network while preserving network connectivity, and the Range Assignment (RA) problem, which goes further in the goal of saving energy finding the optimal transmission power for each individual node. These two problems emphasize the construction of an optimal topology. Distributed topology construction protocols are described next. Here, we are more concerned about building a “good quality” topology while being able to implement it in an efficient fashion, where efficient means with low energy consumption, low computational and message complexity, and so on. These protocols make use of location, direction, neighbor, and routing information to achieve their objectives. Finally, the chapter also includes mechanisms that find the reduced topology by controlling the transmission power in heterogeneous networks, i.e., without assuming similar nodes, which is, in fact, a possible scenario.