Utilization and fairness in spectrum assignment for opportunistic spectrum access

Abstract

Abstract-The Open Spectrum approach to spectrum access can achieve near-optimal utilization by allowing devices to sense and utilize available spectrum opportunistically. However, a naive distributed spectrum assignment can lead to significant interference between devices. In this paper, we define a general framework that defines the spectrum access problem for several definitions of overall system utility. By reducing the allocation problem to a variant of the graph coloring problem, we show that the global optimization problem is NP-hard, and provide a general approximation methodology through vertex labeling. We examine both a centralized strategy, where a central server calculates an allocation assignment based on global knowledge, and a distributed approach, where devices collaborate to negotiate local channel assignments towards global optimization. Our experimental results show that our allocation algorithms can dramatically reduce interference and improve throughput (as much as 12-fold). Further simulations show that our distributed algorithms generate allocation assignments similar in quality to our centralized algorithms using global knowledge, while incurring substantially less computational complexity in the process.

Spectrum Allocation Based on an Improved Gravitational Search Algorithm

“…First, we introduce the evaluation criteria for algorithm performance. Second, we construct the environment for experiments and initialize parameters for algorithms (IGSA, GSA [19], PSO [23] and color sensitive graph coloring(CSGC) [24]). Third, we conduct experiments and analyze the experimental results.…”

“…Each individual performs one fitness evaluation after an iteration, then the best fitness value of each algorithm is selected to validate the performance of the algorithm. In addition, we use the CSGC which is commonly used to solve the spectrum allocation problem as the benchmark algorithm to compare with others, for more information on CSGC, please refer to [24]. All algorithms use the same topology, and the number of repetitions in convergence experiments is 500, others are 50, and the average is finally taken.…”

SMART: A SpectruM-Aware ClusteR-based rouTing scheme for distributed cognitive radio networks

“…The graph domination principle selects a small dominating set of nodes to serve as clusterheads and the rest of the nodes associate themselves with the clusterheads and become their member nodes.It has been shown that finding the minimum dominating set in distributed networks [11] and selection of a common channel [12] are both NP-hard problems. Hence, this article proposes heuristic algorithms for SMART, which is a cluster-based routing scheme.…”

A Framework for Data Traffic in Cognitive Radio Networks Using Trusted Token Analyzer Scheme

“…For spectrum allocation, a global optimization scheme is developed based on graph theory [17]. Distributed spectrum allocation based on local bargaining is proposed in [4], where CR users negotiate spectrum assignment within local selforganized groups.…”