First COST 297-HAPCOS Workshop – York, UK 26-27 October 2006 Analysis and performance evaluation of integrated HAP/Satellite architectures

Both HAPS and satellite as stand alone systems represent a flexible infrastructure to provide telecommunication capabilities for a broad set of services. Nevertheless, each of the two technologies can greatly help the other to reduce the impact of some intrinsic limitation in performance. For example, the use of HAPS as intermediate point of access can greatly reduce physical layer requirements for the user terminal and can reduce the perceived latency while the satellite can be effectively used to interconnect HAPSs among one another in a cluster or to connect the HAPS with a very remote location, thus enhancing the actual coverage capability. For these and other reasons an integrated architecture looks very attractive even though complexity must be added on board the HAPS. The paper analyses advantages and disadvantages of the integrated HAPS/Satellite architecture both at system level and at service level. Moreover, the results of design activities at physical layer (link budget) and at transport layer (TCP protocol) will be shown.