Traffic and resource management in multi-tier networks exploiting satellite coverage

Multi-tier cellular systems can answer the rising need for high transmission capacity and provide solutions for supporting heterogeneous (narrow-band and broad-band) traffic. The system analysed in this paper consists of a GEO satellite spot covering micro and macro-cellular layers to provide global user reachability and additional bandwidth. Enhanced traffic and resource management algorithms are proposed to effectively exploit the potential advantages of the multi-tier solution. The basic feature is the allocation of each connection to the most convenient hierarchical layer, according to the user mobility profile (fast/slow) and traffic nature. The system is loaded by heterogeneous traffic sources with different requirements in terms of bandwidth on the two radio link directions (symmetric and asymmetric data), delivery requirements and integrity needs. Algorithms are compared under different external conditions and their performance is assessed in terms of new call blocking and handoff dropping probabilities