CQI Maps for Optimized Data Distribution

The number of connected cars is growing continuously. Many car manufacturers offer systems, which provide online content to the passengers, mostly infotainment and information data. Although new wireless data communications technologies like LTE will offer much more performance, the increasing number of mobile data users in combination with higher individual data traffic will nullify the higher capacities. Mobile data bandwidth will remain a rare commodity. If next generations driver assistance systems should be supplied with data from central servers in time and according to their individual priorities, it is important to make optimal use of the available resources. Considering the changing channel conditions of the wireless links offers potential for improvements, since the channel quality has a direct influence on the utilization of the data channel. HSPA and LTE use the so called Channel Quality Indicator (CQI) as a measure of the channel conditions. Summarized in a map, server-side applications can use a priori knowledge of the location-dependent channel quality to optimize the data distribution to mobile clients. This paper describes the process of creating CQI maps for HSDPA networks, from the initial collection of raw data to the final validation of the proposed concept.