Intelligent management of radio resources in UMTS access networks

The efficient management of scarce radio resources is the heart of any mobile communication system. By the means of power control, load control, and handover, any cellular system can be kept in a stable operational state for all traffic and radio environment conditions. This control mechanism is called radio resource management (RRM). Essentially, RRM algorithms affect the mobile system performance and provide service quality. Therefore, RRM efficiency is a major differentiating factor with regard to the radio access network realizations, especially as the algorithms typically are not standardized. Lucent Technologies has conducted extensive studies to verify the design, evaluate the performance, and prove the excellence of the realized algorithms in the Universal Mobile Telecommunications System (UMTS) access network. This paper describes the theoretical background of WCDMA/UMTS system performance evaluations and shows how this knowledge was turned into a flexible simulation tool. This tool can handle dynamic effects of RRM algorithms in cellular network models by incorporating realistic radio propagation with moving mobile stations generating a mixture of voice and data traffic. The paper further provides examples from a huge series of studies investigating the dynamics of code division multiple access (CDMA) radio systems. These studies and Lucent's long experience with developing, deploying, and optimizing CDMA networks will contribute to shortening the introduction phase of the new UMTS radio network technology.