Cognitive extensions to existing wireless technology

Spectrum assigned by the Federal Communication Commission (FCC) for public safety has not been fully utilized. As such, communication service providers and equipment vendors desire to examine the feasibility of recouping their investment in spectrum purchase and management. We propose a cost-effective solution by introducing a cognitive extension that achieves desired frequency agility while utilizing existing device base-band operations. The proposed method provides a cost efficient solution for cognitive radio implementation. This paper describes the design and implementation of a prototype device that extends the baseband, MAC, and routing functionalities of an IEEE 802.11b access point. The work presented herein describes an experimental network analyses that investigates the impact of the proposed extension on overall network performance parameters, including throughput, packet loss, and delay. Results show minimal impact on performance when switching time between transmitting and receiving paths is equal to or less than 6 μs. Achieved throughput for a wireless device setup at a 1 Mbps data rate on a one-hop network is 0.74 Mbps.