Eunsun Kim

Mobile TV White Space with Multi-Region Based Mobility Procedure

Current regulations require that portable unlicensed devices operating in TV white space perform a channel availability query (CAQ) before transmitting whenever they move more than 100m. Since this mobility constraint gives rise to frequent CAQs, the Federal Communications Commission allows a region-based mobility procedure (RMP) to help reduce the number of CAQs. Since the performance of the RMP cannot be precisely evaluated based only on the number of CAQs, in this letter, we formulate an achievable throughput in terms of the average number of available channels, the effective data transmission time, and the TV band database fees. We discover that the achievable throughput for the conventional single RMP is degraded when the radius of the region is not properly determined. In order to alleviate this performance degradation, we propose a multi-RMP using multiple radii in order to obtain multiple available channel lists. Simulation results show that the proposed multi-RMP can mitigate the performance degradation. In addition, the use of multi-RMP enhances the maximum throughput compared to the single RMP.

Directional Information Based Mobility Procedure for Throughput Enhancement in Mobile TVWS

Portable unlicensed devices operating in TV white space must adhere to FCC rules designed to protect licensed devices. These rules decrease the achievable throughput for the portable unlicensed devices because the portable unlicensed devices are required to perform a channel availability query (CAQ) before transmitting. In order to reduce the number of CAQs, the Federal Communications Commission allows a region based mobility procedure (RMP). In this paper, we propose a new-RMP using directional information in order to enhance the achievable throughput. Directional information enables an unlicensed portable device to increase its achievable throughput by considering a uni- directional region that is smaller than an omni-directional region. Simulation results show that the proposed RMPs enhance the achievable throughput compared to the conventional RMPs. In addition, the achievable throughput for the proposed RMP using a navigation system is greatly enhanced compared to the conventional RMPs.