Abstract:
The inherent advantages of the Ultra High Frequency (UHF) spectrum band localized in the Television White Space (TVWS) and the need to manage the artificially scarce spectrum very well has motivated wide spread research by academics. The studies were based mainly on how to change from the rigid way by which radio spectrum is been managed, whereby it is licensed to a specific user, to a more flexible way, which would allow it to be shared between primary (licensed) user and secondary (unlicensed) user. However, the solution proffered using Cognitive Radio is capital intensive compared to geospatial approach. Hence, the need for this study, which is the development of a model for predicting TVWS in Ondo State, Nigeria, to facilitate the secondary usage of spectrum economically in Ondo State. This would provide a way to tap into the good propagation characteristic of the UHF TV frequency bands localized in the Television White Spaces (TVWSs). This was achieved through the measurements of the Ondo State Radiovision Corporation (OSRC TV), Akure, transmission signal strength by using DBC1173 signal analyzer. Four routes (1,2,3, and 4), cutting through the entire state, were mapped out and the measurements were taken along the routes. A model for predicting TVWS in Ondo State, Nigeria was developed from the measurements carried out as well as a map to show locations of the white spaces in the state. This aims to optimally utilize the frequency allocated to the channel (OSRC TV operating on channel 23, with vision frequency of 487.25 MHz). The evaluation and analysis of the derived model was carried out with the aid of its prediction errors, calculated through comparison with the measured values of the signal, coupled with the same errors from eight existing empirical models. The developed prediction model’s error and Correlation Analyses showed that the derived model has an average error of -51.32 dB over estimation) along Route 1. Route 2 is -3.07 dB. Along Route 3, it is 9.06 dB and -71.90 dB (overestimation) along Route 4.The map model clearly shows that the white space ranges from -95.41 dBm downwards. Results of the evaluations and analyses show that, on the average, the derived model performance is 39.92%. However, the modeled map shows all the TVWSs clearly.
