Adaptive Radio Resource Management Scheme for UMTS Packet Data

Inhalt:
In packet-switched cellular systems the question of when to release the different resources of the system emerges. Typically, UMTS systems use static timeouts to decide on the time after which idle radio and code resources are released. Unfortunately, the optimal timeout values depend on many parameters, which are not necessarily under full control of the operator. Examples are the characteristics of packet traffic, the traffic mix between data and voice and the current system utilization. In the paper, we propose a new scheme based on the Simplex method that automatically adapts to the current situation. In our scheme, resources, hold by inactive mobiles, are released based on the demand and the load situation rather than the inactivity time of the mobile. We present first results of our simulations that show that the new scheme allows for a reduction of the blocking and dropping rate by about 50% without negative impact on other parameters. In addition, the mean call setup time could be reduced.