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Abstract | ||
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We propose a new spectrum-access etiquette for cognitive radios in a spectrum commons. When congestion might block a new device from initiating a call, the surrounding devices coordinate their actions and locally reassign their spectrum to create a gap for the new entrant. The etiquette is designed for devices operating dissimilar services with different bandwidth and quality requirements. It generates link-level interference temperature constraints and finds a satisfying assignment using local search. In experimental simulation, we demonstrate that the etiquette provides significantly higher completion rates while improving the quality of the completed calls. I. INTRODUCTION The driving force for new radio spectrum regimes has been the inefficiency of existing mechanisms. The most basic of these range from "spectrum licensing" providing exclusive use for a given contractual period, to having a "spectrum commons" (1), (2). A spectrum commons (e.g. (3)) is basically an allotment of unlicensed spectrum which any user may access opportunistically. However, a completely unregulated commons is unlikely to be successful, and so some rules and etiquettes for access and behaviour are likely to be required. The key question is then: can we devise an etiquette which is both desirable and technically feasible? To get maximum spectrum usage, it is likely that many different types of traffic, with widely different bandwidth, power and range requirements, will have to co-exist in the commons (3), (4). While there is increasing interest in eti- quettes which can work with dissimilar or heterogeneous services, e.g. 802.11a/b/g, 802.16, Bluetooth and UWB sharing the spectrum "horizontally" (having equal priority and status), most proposed (and implemented) etiquettes only consider homogeneous sets of devices/services. These etiquettes are usually described by whether they are cooperative (or not), or pro-active (rather than reactive). Cooperative etiquettes may be centralised - depending on a server, e.g. (5); or distributed (often involving "cognitive radios" to sense the environment, make decisions and shape their transmitted signal - in terms of output power, frequency mask, codebook etc.) e.g. (6). Some etiquettes involve "simple" operations conducted by an individual radio independently of other radios to improve global utilisation of radio resources. More complex etiquettes require interaction amongst devices to locally optimise their use of the spectrum. These might rely on device priority or micro-auctions to determine which device might pay the most for the spectrum and assign that spectrum accordingly e.g. (7), or redress the assignments locally e.g. (8). Regardless of the mechanism, these etiquettes usually require a means of communication and a "common signalling control channel" (CSCC) is widely proposed (3), (7). We propose and implement a local reassignment etiquette for dissimilar wireless systems, using link-level interference temperature constraints which faithfully capture the service requirements of the links involved. The aim of this etiquette is to increase access by reassigning spectrum to produce a "spectrum hole" which allows additional call sessions. We demonstrate in an experimental simulation that this etiquette offers a significant increase in the number of completed calls, and simultaneously improves the quality of the completed calls. |
Year | DOI | Venue |
|---|---|---|
2007 | 10.1109/CROWNCOM.2007.4549839 | Orlando, FL, USA |
Keywords | Field | DocType |
bandwidth,spectrum,bluetooth,satisfiability,computer science,cognitive radio,shape,local search,temperature | Telecommunications,Computer science,Computer network,Bandwidth (signal processing),Interference (wave propagation),Local search (optimization),Etiquette,Telecommunication computing,Bluetooth,Cognitive radio,Commons | Conference |
ISBN | Citations | PageRank |
978-1-4244-0815-3 | 3 | 0.45 |
References | Authors | |
8 | 4 | |
Name | Order | Citations | PageRank |
|---|---|---|---|
| Bater, J. | 1 | 22 | 1.94 |
| Hwee Pink Tan | 2 | 18 | 2.78 |
| Kenneth N Brown | 3 | 4 | 0.81 |
| L. E. Doyle | 4 | 487 | 45.61 |