CONGESTION CONTROL OF CIRCUIT SWITCHED SERVICES IN 3RD GENERATION RADIO ACCESS NETWORKS USING TIME-WINDOW BASED PRE-EMPTIVE ALGORITHMS

摘要

Congestion control in 3rd Generation Radio Access Networks (3GRAN) can be achieved for Packet Switched (PSW) service by usingfasttransport-format control services at the Medium Access Control (MAC) layer [1], which reduces the bit-rate during congestion to ameliorate the situation. However, for Circuit Switched (CSW) services such transport-format control is not possible, thus the only way to mitigate congestion is to preempt or abort connections. One form of congestion control is already inherent in the Universal Terrestrial Radio Access (UTRA), where CSW services are dropped when in outage for a long'contiguous period [2]. More innovative congestion control algorithms can be implemented at the Call Admission Control (CAC), which may result in improved performances. One such algorithm is presented in this paper that has shown to increase CSW service performance in the midst of congestion.