Consider the problem of computing the minimum-weight multicast route in an optical network with both nonsplitting and splitting nodes. This problem can be reduced to the minimum Hamiltonian path problem when all nodes are nonsplitting, and the Steiner minimum tree problem when all nodes are splitting. Therefore, the problem is NP-hard. Previously, the best known polynomial-time approximation ha...

In wireless sensor networks (WSN’s), majority of its applications necessitate the confidentiality of information they transmit. This can be achieved through secure key management schemes. In this paper, a key pre-distribution scheme for randomized secured routing is proposed for WSN. Initially, the sink utilizes the one hop neighbor information of nodes to predistribute keys. It randomly choose...

the stability of a communication network composed of processing nodes and communication links is of prime importance to network designers. as the network begins losing links or nodes, eventually there is a loss in its effectiveness. thus, communication networks must be constructed to be as stable as possible, not only with respect to the initial disruption, but also with respect to the possible...

Among numerous NP-hard problems, the Traveling Salesman Problem (TSP) has been one of the most explored, yet unknown one. Even a minor modification changes the problem’s status, calling for a different solution. The Generalized Traveling Salesman Problem (GTSP)expands the TSP to a much more complicated form, replacing single nodes with a group or cluster of nodes, where the objective is to fi...

The stability of a communication network composed of processing nodes and communication links is of prime importance to network designers. As the network begins losing links or nodes, eventually there is a loss in its effectiveness. Thus, communication networks must be constructed to be as stable as possible, not only with respect to the initial disruption, but also with respect to the possible...

Given a connected graph G = (V, E) with non-negative edge costs, and a set of " special " nodes S ⊂ V , a subgraph of G is a Steiner tree, if it is a tree that spans (connects) all the (" special ") nodes in S. The Steiner Tree problem is to find a Steiner Tree of minimum weight (cost). Steiner Tree is an important NP-hard problem that is often encountered in practice. Examples include design o...

For any non-negative integer K, aK-observer P of a network N is a set of nodes in N such that each message, that travels at least K hops in N , is handled (and so observed) by at least one node in P . A K-observer P of a network N is minimum iff the number of nodes in P is less than or equal the number of nodes in every K-observer of N . The nodes in a minimum K-observer of a network N can be u...

A wireless sensor network is an ad hoc network consisting of numerous sensor devices (nodes). These nodes are linked via short-range ad hoc radio connections. Each node in such a network has a limited energy resource (battery), and each node operates unattended. Consequently, energy efficiency is an important design consideration for these networks. Inspired by the fact that in complex systems ...