Traffic control algorithms for a multi access network scenario comprising GPRS and UMTS

Next generation wireless communication systems will bring new architecture concepts, new spectrum allocation policies and smart resource management in a multi-network environment [ R. Berezdivin, et al., March 2002]. Within this context the IST DRiVE project [IST DRiVE Project Website, http://www.ist-drive.org/] aims at enabling a spectrum-efficient high-quality wireless IP in a heterogeneous multi-radio environment to deliver in-vehicle services. This paper assumes a multi-network scenario comprising GPRS and UMTS radio access networks (RAN) and proposes several schemes for controlling and distributing the network traffic over these two RANs, increasing the spectrum efficiency of the whole system by ensuring that mobile terminals are served by the optimum radio access technology available. This is achieved by assigning a cost to each service that the network can provide, taking into account both system load and system resource availability, and enabling the mobile terminal to select the most efficient RAN, retaining the quality the user asks for. The results show that a gain, in terms of percentage of satisfied users, of more than 15% can be obtained by the multi-network system compared to the case of no traffic distribution process, thus leading to a more efficient spectrum usage.