Can Cognitive Radio Access to TV White Spaces Support Future Home Networks?

There is a growing demand for high data-rate mobile and indoor services at a reasonable cost, and using an indoor wireless system at end of the ADSL+ or fibre line is one potential way of meeting this demand. Industry players such as fixed-line and cellular operators have adopted similar approaches but based around different wireless technologies such as WiFi or HSPA femtocells and potentially LTE/WiMAX in the future. However due to issues related to interference in the license-exempt band and limited spectrum availability in the licensed band there are some doubts as to whether or not the available wireless options will be able to effectively distribute the high bandwidths within a home environment. With use of cognitive radio technology, the digital TV switchover program, offers a potential opportunity to address this issue. The aim of this paper is to assess the feasibility of using the TV White Space(TVWS) spectrum for home networking services and compare the performance with that of other license-exempt spectral bands, namely 2.4 GHz and 5 GHz ISM band. It studies the limitations in presence of interference and identifies the operating conditions when the system performance would start to become unacceptable. Using analytical and simulation techniques, it is shown that the performance of TVWS spectral outperforms the 5 GHz and 2.4 GHz for low to medium traffic loadings (around 2 Mb/s per home) at significantly lower energy requirements. However, to achieve these gains (a) the use of spectrum aggregation techniques and (b) operation at low power levels, i.e, below 3 dBm per channel becomes essential. The work also shows that for heavy traffic loadings (6 Mb/s and above per home) in dense deployment densities, TVWS band should be used as complementary interface for congestion relief instead.