Quality-of-Service provisioning for mobile voice and data services over ATM network using AAL2

Abstract

Asynchronous transfer mode(ATM) adaptation layer 2(AAL2) has been designed to transport voice, fax, and voice-band data(VBD) traffic efficiently over an ATM virtual circuit by ITU-T and ATM Forum. It is expected that ATM/AAL2 will be used with CDMA in the access part of the 3rd generation mobile works. Recently the amount of mobile data traffic is increasing remarkably and expected to increase continuously because of the wide use of mobile phones, portable computers or personal digital assistant (PDA) with networking capabilities. So it is evident that as efficient scheduling scheme to guarantee the QoS requirement of low bit rate voice and high bit rate data at the same time will be needed. In this thesis a novel scheduling scheme and as architecture of AAL2 system if proposed, which can provide QoS guaranteeing to mobile voice traffic, sensitive to the delay, while improving resource utilization by processing mobile voice and data traffic with a single AAL2 multiplexer. Our scheme does not multiplex voice and data traffic into the same cells, even though only one AAL2 multiplexer is used, therefore ATM Traffic Management and Resource Management(TM/RM) techniques can be applied. By assigning a time threshold value and queue length threshold to voice traffic and serving voice traffic sequentially up to a predetermined value, to bounds the CPS=Packet queue delay and cell transmission queue delay. By forcing to pad in an appropriate situation it bounds the cell-assembly delay, too. Consequently the delay that any mobile voice packet may experience in an AAL2 system is strictly bounded. Meanwhile the data traffic is served in the vacant time when voice traffic is not served. Since the voice traffic is delayed in the AAL2 layer until it meets any of threshold values, data traffic can have much chances to be served, which results in the improvement in data packet loss probability. At the ATM layer the cells containing voice CPS-Packets are served prior to the cell...