Abstract-In this paper we study asymmetric power assignments which induce a low energy k-strongly connected communication graph with spanner properties. We address two spanner models: energy and distance. The former serves as an indicator for the energy consumed in a message propagation between two nodes, while the latter reflects the geographic properties of routing in the induced communication graph. We consider a random wireless ad-hoc network with |V | = n nodes distributed uniformly and independently in a unit square.For k ∈ {1, 2} we propose several power assignments which obtain a good bicriteria approximation on the total cost and stretch factor under the two models. For k > 2 we analyze a power assignment developed in [1], and derive some interesting bounds on the stretch factor for both models as well. We also describe how to compute all the power assignments distributively, and provide simulation results. To the best of our knowledge, these are the first provable theoretical bounds for low cost spanners in wireless ad-hoc networks.

Abstract. A wireless ad-hoc network is a collection of transceivers positioned in the plane. Each transceiver is equipped with a limited, nonreplenishable battery charge. The battery charge is then reduced after each transmission, depending on the transmission distance. One of the major problems in wireless network design is to route network traffic efficiently so as to maximize the network lifetime, i.e., the number of successful transmissions. This problem is known to be NP-Hard for a variety of network operations. In this paper we are interested in two fundamental types of transmissions, broadcast and data gathering. We provide polynomial time approximation algorithms, with guaranteed performance bounds, for the maximum lifetime problem under two communication models, omnidirectional and unidirectional antennas. We also consider an extended variant of the maximum lifetime problem, which simultaneously satisfies additional constraints, such as bounded hop-diameter and degree of the routing tree, and minimizing the total energy used in a single transmission.

Abstract. A wireless ad-hoc network is a collection of transceivers positioned in the plane. Each transceiver is equipped with a limited, nonreplenishable battery charge. The battery charge is then reduced after each transmission, depending on the transmission distance. One of the major problems in wireless network design is to route network traffic efficiently so as to maximize the network lifetime, i.e., the number of successful transmissions. This problem is known to be NP-Hard for a variety of network operations. In this paper we are interested in two fundamental types of transmissions, broadcast and data gathering. We provide polynomial time approximation algorithms, with guaranteed performance bounds, for the maximum lifetime problem under two communication models, omnidirectional and unidirectional antennas. We also consider an extended variant of the maximum lifetime problem, which simultaneously satisfies additional constraints, such as bounded hop-diameter and degree of the routing tree, and minimizing the total energy used in a single transmission.

No abstract

No abstract