The rapid development and close maturity of unlicensed WLAN systems raise the problem of their coexistence with the well-known next generation cellular systems, i.e. 3G systems. 3G systems primarily developed to provide mobile multimedia access led to the appearance of multiservices multi-applications user profiles, which raised the need for advanced schemes in order to handle users' radio links quality and ensure that the proper service-related QoS is provided. In order to face this challenge, it could be valuable in specific configurations to take advantage of the WLAN technology, designed to provide users with high data rates within a limited coverage range. Diversifying the radio access possibilities would help in optimising system performance. Indeed, in specific configurations related mainly to dense urban areas, jointly deploying 3G and WLAN networks could potentially bring advantages in terms of spectrum management as one technology could be more adapted (depending on the users' profiles) than the other and, in addition, could lower the costs of providing the expected service to the users. (5 pages)