Planning reliable UMTS terrestrial access networks

The Universal Mobile Telecommunication System (UMTS) will play a very important role in the telecommunication market of the near future. Due to the wide range of services and the increased transmission capacity, UMTS will become one of the most important access network types. The proposed topology of the UMTS terrestrial access network is tree-like, but the high amount of carried traffic requires a more reliable network structure. In this article we introduce two types of heuristic algorithms to solve this problem, and we plan network topologies having a low magnitude of traffic loss in case of failures. One of our algorithms solves the problem by modifying the tree-topology, while others expand the network by inserting additional links. In this article, we show how to find a good compromise between topology refinement and network expansion in the case of realistic network scenarios, and we confirm our results by detailed tests.