Abstract-Most topology control algorithms for wireless ad hoc networks strive to reduce energy consumption by creating a sparse topology with few long-distance links. However, in a sparse topology, the average path length is relatively large (increasing end-to-end delay), and the number of vertex-disjoint paths between source-destination pairs is relatively small (reducing faulttolerance). Unlike traditional topology control algorithms that generate a single topology with a certain property, we propose a distributed algorithm that generates a family of topologies with a range of characteristics. The network designer can choose a suitable topology by simply tuning a single parameter ∆ (power savings threshold), trading off energy savings for other features such as low latency and fault-tolerance. For the topologies generated by the proposed algorithm, we also provide an analytical model to estimate their structural density. The accuracy of the analytical model is validated with extensive simulation results.I. INTRODUCTION Wireless ad hoc networks are known as "networks without networking", since they do not rely on any pre-configured fixed infrastructure. Rather, the nodes can be deployed spontaneously, perhaps at random, and then be dynamically reconfigured into a manageable and controllable network topology. Such dynamic topology control is widely used in wireless sensor networks, vehicular networks, and wireless mesh network environments, to name a few.Many of these wireless ad hoc networks consist of mobile nodes equipped with limited power sources, such as a battery or a solar cell. Thus energy consumption is a prime consideration in designing such networks. The transmission power between a pair of communicating nodes is one of the dominant factors in the overall energy consumption. Since the transmission power requirement grows (at least) quadratically with the distance between the communicating parties, using one or more nearby neighboring nodes as intermediate relays can dramatically reduce energy consumption. Thus any energy-aware topology control algorithm gives preference to short-distance links rather than long-distance links.In general, a topology control algorithm works as follows. Each node in the network classifies all of its directly reachable neighbors as either "close" or "far". The "closeness" of a neighbor is based on a suitably chosen objective function. If the goal is to conserve energy, then direct communication is used for the close neighbors, while indirect communication (via a relay node) is used for the far neighbors. After the classification step, each node reduces its transmission power to the minimum required to communicate with all of its close neighbors. Thereby a node uses one or more close neighbors to relay information to the far neighbors.