Managing symmetric and asymmetric data traffic in integrated terrestrial-cellular and satellite systems

Multitier coverage meets the increasing need for high transmission capacity, and therefore can provide solutions to support heterogeneous (narrowband and broadband) data traffic over wide-area cellular data platforms. The system analyzed in this article consists of GEO satellite spot coverage, which is added to the micro- and macrocellular layers of a terrestrial network segment to provide global user reachability and additional bandwidth. An enhanced data traffic management policy is proposed to exploit the potential advantages of the multitier solution. The basic features are: a simple policy to allocate each connection to the most convenient hierarchical layer, on the basis of user mobility profile (fast/slow) and traffic characteristics; dynamic partitioning of the satellite channels between the uplink and downlink; and the partial limitation of symmetric data access to the terrestrial segment. The envisioned platform has been conceived to serve heterogeneous data traffic sources with different requirements in terms of bandwidth in the two radio link directions (symmetric and asymmetric data), in addition to traditional voice telephony terminals.