Characterization of Radio Signal Strength Fluctuations in Road Scenarios for Cellular Vehicular Network Planning in LTE

Road coverage will be a key issue for the success of connected car applications. In this work, a comprehensive analysis of radio signal strength fluctuations on roads in a Long Term Evolution (LTE) system is presented. For this purpose, a measurement campaign based on drive tests was carried out to assess the coverage levels that can be expected on ordinary roads by normal in-car terminals in a country of the European Union. Measurements were collected on 1,000 km of road by 2 vehicles covering the same route. By comparing signal level samples at the same geographical location, taken at slightly different times, a statistical model of fluctuations is derived. Then, the impact of different factors (e.g., shadowing, environment, handover, etc.) on the signal level received from the serving cell is assessed. Results show that large deviations of signal level (up to 23 dB) are observed at the same geographical location.