What and how much to gain by spectrum agility?
Journal
IEEE Journal on Selected Areas in Communications
Journal Volume
25
Journal Issue
3
Pages
576-588
Date Issued
2007
Author(s)
Abstract
Static spectrum allocation prohibits radio devices from using spectral bands designated for others. As a result, some bands are under-utilized while other bands are over-populated with radio devices. To remedy this problem, the concept of spectrum agility has been considered so as to enable devices to opportunistically utilize others' spectral bands. In order to help realize this concept, we establish an analytical model to derive performance metrics, including spectrum utilization and spectrum-access blocking time in spectral-agile communication systems. We then propose three basic building blocks for spectral-agile systems, namely spectrum opportunity discovery, spectrum opportunity management, and spectrum usage coordination, and develop protocols for each blocks. These protocols are integrated with the IEEE 802.11 protocol, and simulated using ns-2 to evaluate the protocol overhead. The simulation results show that our proposed protocols can improve the throughput of an IEEE 802.11 wireless LAN by 90% for the simulated scenarios, and the improvements matched well our analytical model. These results demonstrate the great potential of using spectrum agility for improving spectral utilization in an efficient, distributed, and autonomous manner. © 2007 IEEE.
Subjects
Cognitive radios; Programmable wireless networks; Spectrum agility
Other Subjects
Cognitive radios; Programmable wireless networks; Spectrum agility; Spectrum usage coordination; Communication systems; Frequency bands; Mathematical models; Network protocols; Radio equipment; Throughput; Spectrum analysis
Type
journal article