Effect of EIRP Levels of TV White Space Devices on Network Channel Capacity and User Capacity

Abstract

This study explores the impact of Effective Isotropic Radiated Power (EIRP) of Television White Space Devices (TVWSDs) on overall channel capacity and per-user capacity within TV White Space (TVWS) networks. Using a simulation-based evaluation, the performance metrics were analysed with respect to varying TVWSD EIRP levels under different targets of Signal-to-Interference-plus-Noise Ratio (SINR). The results reveal that channel capacity initially increases with EIRP due to enhanced signal strength but subsequently decreases beyond a certain EIRP threshold as interference becomes dominant. This degradation is exacerbated by the interplay between EIRP and the separation distance of customer premises equipment (CPEs), which although intended to mitigate interference, cannot fully compensate at high EIRP levels. Notably, for a low SINR target of 10 dB, a high EIRP of 35 dBm achieves a channel capacity of up to 25 Mbps, while for higher SINR targets of 15 dB and 20 dB, the capacities drop to approximately 0 and 12.5 Mbps, respectively. Similarly, analysis of per-user capacity for 10 users indicates that systems with higher SINR requirements are more sensitive to interference, reaching peak capacity at lower EIRP values (e.g., 23 dBm for 20 dB SINR), whereas lower SINR targets tolerate greater EIRP before experiencing capacity degradation. These findings underscore the critical importance of adaptive power control in optimizing TVWS network performance under variable environmental and system constraints.