Akinbolati A, Ajewole M O, Adediji A T, Ojo J S
Department of Physics, Federal University Dutsin-Ma, P. M.B 5001, Dutsin-Ma, Nigeria.
Department of Physics, Federal University of Technology, P. M.B 704, Akure, Nigeria.
Heliyon. 2020 Mar 18;6(3):e03599. doi: 10.1016/j.heliyon.2020.e03599. eCollection 2020 Mar.
This study investigated the propagation curves and coverage areas of some Digital Terrestrial Television Broadcast Stations (DTTBS) over four climatic zones of coastal (Lagos), tropical rain forest (Akure), Sudan Savannah (Kaduna) and Sahel Savannah (Katsina) cities of Nigeria. Measurement of the Received Signal Strength (RSS) was carried out along different routes with each of the DTTBS as reference points. Measurements of RSS were carried out using two specified antenna receiver heights of 1.5 and 3.0 m for each data point. The GPS receiver was used to measure the geographic coordinates, elevation and Line of Sight (LOS) of data points along the routes in a drive test. Measurement was done during dry and wet season months at 1 km interval up to about 20 km in each of the selected routes covering a period of three years (2016-2018). Mean data were obtained and used to generate the propagation curves and the coverage areas over the study locations. Generally, results revealed that RSS undulates with LOS separation distance from DTTBS in all routes irrespective of seasons and routes. Particularly, RSS reduces to about half of its base station's value at about 8 and 12 km LOS from the DTTBS in Akure and Katsina respectively while, it reduces to about half of its base station's value at about 6 km from the DTTBS in Lagos and Kaduna. The implication of this is that higher coverage areas were obtained in suburban compared to urban cities. In addition, radial maps showing coverage areas and their grades useful for networking purposes were generated. Television White Spaces (TVWS) for secondary users were also proposed. For networking purposes and spatial arrangements of DTTBS that will ensure optimum coverage over the study locations, DTTBS can be sited at 8.0 and 13.5 km (LOS) interval from each other in urban and sub urban cities respectively. The overall results will enable system engineers to know the appropriate distance(s) and locations to site additional DTTBS for networking purposes and prepare power budget for optimum coverage area and good quality of services for terrestrial digital channels.
本研究调查了尼日利亚沿海（拉各斯）、热带雨林（阿库雷）、苏丹草原（卡杜纳）和萨赫勒草原（卡齐纳）这四个气候区的一些数字地面电视广播电台（DTTBS）的传播曲线和覆盖区域。以每个DTTBS为参考点，沿着不同路线进行接收信号强度（RSS）的测量。对于每个数据点，使用1.5米和3.0米这两个指定的天线接收器高度进行RSS测量。在路测中，使用GPS接收器测量沿路线的数据点的地理坐标、海拔和视线（LOS）。在干燥和潮湿季节的月份进行测量，在每个选定路线上以1公里的间隔进行，直至约20公里，为期三年（2016 - 2018年）。获取平均数据并用于生成研究地点的传播曲线和覆盖区域。总体而言，结果表明，无论季节和路线如何，所有路线上的RSS都随与DTTBS的LOS分离距离而波动。特别是，在阿库雷和卡齐纳，分别在距DTTBS约8公里和12公里的LOS处，RSS降至其基站值的约一半，而在拉各斯和卡杜纳，在距DTTBS约6公里处，RSS降至其基站值的约一半。这意味着与城市相比，郊区获得了更高的覆盖区域。此外，还生成了显示覆盖区域及其等级的径向地图，这些地图对联网很有用。还为次要用户提出了电视空白频段（TVWS）。为了联网目的以及确保在研究地点实现最佳覆盖的DTTBS的空间布局，在城市和郊区，DTTBS彼此之间的间隔分别可为8.0公里和13.5公里（LOS）。总体结果将使系统工程师能够了解为联网目的设置额外DTTBS的合适距离和位置，并为地面数字频道的最佳覆盖区域和良好服务质量编制功率预算。
