| Network operators are implementing multiple services, i.e., speech and data, on multiple cellular network types, including second and third generation networks-and potentially Wireless Local Area Networks and/or satellite networks. The vision of 4G is to enable multimode mobile stations to roam across these diverse networks seamlessly and transparently. Mobile stations will be able to control the network they are served by, thus enabling the customer to select the least-cost network capable of providing the requested service.; However network operators can also benefit by providing seamless, transparent mobility across networks. ATM and the Erlang B model demonstrate that efficiency of scale can be achieved with a single, common pipe for communications. We define a ‘super-network’ or ‘supernet’ as the capability of engineering traffic across the component networks or ‘compnets’ managed by a single operator. This study investigates how traffic engineering can occur across cellular networks, by eliminating the tight bond between a call and its preferred compnet. The bond can be broken either by allowing the compnet to expand beyond its original frequency allocation or by allowing calls to be carried by other compnets. The study investigates the impact on efficiency and QoS when services with varied bandwidth requirements share network resources. The study then investigates load sharing load balancing and service balancing of integrated cellular networks, using vertical handovers for connection overflow and call placement. The analysis compares different call handling models using simulation and Ndimensional Markov Chain models.; Once the advantages of moving connections between diverse networks are quantified, applications that use these techniques are evaluated. Operators can benefit by conservatively dimensioning their networks, using the load sharing capability of super-networks. Another benefit is network survivability, which arises due to the redundancy inherent in supernets consisting of diverse networks, technologies, frequency bands and cell sizes, combined with the multimode capabilities in mobile stations and base stations. The concept of a supernet can extend even beyond the set of networks managed by a single operator. In the global Supernet, operators can overflow connections to other operators, with which they have overflow agreements. |
