The design of wireless telecommunications networks is a complex process, which requires solving simultaneously many difficult combinatorial optimization problems. We propose a taboo-search approach dedicated to one of the aforementioned design optimization problems, namely the cell assignment problem. Our approach defines a series of moves applicable to an initial solution in order to improve the cost and establish the feasibility of the solution. For this purpose, we identify a gain structure with update procedures to efficiently choose the best solution in the current neighborhood. The results are generally good in comparison with those obtained through other heuristic methods.

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The "explosive growth in bursty traffic" changes the network dynamics and requires a good evaluation of various classes of service when designing an access network. From a topological standpoint, the multiservice networks in this paper are heterogeneous systems which integrate both a core and some wireless access networks into an infrastructure similar to third-generation wireless networks. Such networks require reliable and cost-effective solutions to the problem of selecting access technologies for satisfying performance and quality of service requirements related to the services and applications envisioned. This paper analyzes the reliability aspects of some access network topologies to insure a certain level of quality of service at the lowest cost for the end users. It considers a mass market equivalent to 1.6 million subscribers, the objective being to determine the cost the users are ready to pay to benefit from services and applications provided by these multiservice networks. For these purposes, the relative behavior of 3 access-network topologies are studied: the tree with parallel backup links, the ring, and the partially meshed topologies. In ring topology, simulation results show that a great connectivity in the access network is not justified in terms of reliability requirements; the partially meshed topology, even if it has redundant links which affect its cost, outperforms the tree with parallel backup links; and the ring topology is more reliable in terms of disconnected sessions than the tree topology. By considering both reliability and cost, a tree with parallel backup links appears the best topology for the access network and its cost is acceptable for the end user. This study can be extended by: 1) establishing the cost as a function of the quality of service; 2) optimizing the partially meshed topology for more reliable networks; and 3) defining a (shaping) policy to deal with a variety of traffic schemes.

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This paper analyses the pricing framework of multiservice networks and proposes an improved pricing scheme based on the effective bandwidth concept for taking into account quality of service parameters. Based on the deficiencies noted in the classical effective bandwidth scheme (intolerance to user uncertainty and no guarantee on jitter), we propose an improved charging function which gives more flexibility to the user and we introduce an additional constraint to take into account an eventual guarantee on the jitter or delay variation. We also extended the effective bandwidth pricing scheme to the case with guaranteed jitter, in order to take into account and better deal with the various QoS parameters to be considered in 3G networks. Our proposed charging function improves the classical effective bandwidth scheme, while remaining simple in that it requires that the network only monitors the average rate and duration of each connection. It is also fairer than the classical effective bandwidth scheme as it is more flexible related to user uncertainty and the incentive to an efficient use of network resource is preserved. The constraint on the guaranteed jitter was also tested and proved to be viable.