Wireless Personal Communications 24: 11–29, 2003. © 2003 Kluwer Academic Publishers. Printed in the Netherlands. QoS-Based Admission and Load Control Algorithm for Integrated Voice/Data Services over Wideband CDMA MOHAMED H. AHMED and SAMY A. MAHMOUD Department of Systems and Computer Engineering, Carleton University, Ottawa, Canada E-mail: {mhahmed}{mahmoud}@sce.carleton.ca Abstract. In order to maximize the system capacity in third generation wireless system, efficient call admission and load control algorithms are required to handle the different services having diverse traffic patterns and Quality of Service (QoS) requirements. We propose an admission and load control algorithm that considers the network loading information, propagation conditions, and the interference level. The algorithm takes advantage of the new features of third-generation (3G) wireless system such as the reported pilot measurements, auxiliary pilot for smart antennas, and variable spreading gain. Dynamic resource allocation is employed to scale the amount of the assigned radio resources taking the network loading conditions and channel characteristics into consideration. The results show that integrating the voice service and the data service with high transmission rate (>144 Kbps) can be realized using efficient resource management. Keywords: call admission control, W-CDMA performance analysis. 1. Introduction The demand for wireless data applications continues to grow at an accelerating pace. Services such as World Wide Web (WWW), Electronic mail (E-mail), file transfer services, and video transmission are to be offered along with enhanced voice services in 3G systems based on wideband CDMA. Call admission and load control algorithms are essential in CDMA wireless systems since the system capacity is interference-limited. Call admission algorithms are required to maxi- mize the system capacity and preserve the Quality of Service (QoS) in terms of the Energy per bit to Interference density ratio (E b /I o ). Data services have been introduced in the early phases of second-generation wireless networks (GSM, IS-95, and IS-136). However, the provided data rates and QoS were so lim- ited that the data application requirements could not be met. In UMTS/IMT-2000 networks, data transmission rates are up to 2 Mbps for indoor systems, 384 Kbps for pedestrians and 144 Kbps for mobile users using variable spreading gain and multiple codes [1, 2]. Short and infrequent messages are transmitted over random access channel using slotted ALOHA protocol to avoid large overheads. For larger and frequent messages, a connection request is first sent to the BS that determines the possibility of establishing this connection and decides how much resources can be assigned to it [3–5]. The BS might reject this request due to the loading conditions or high interference expected from the user requesting the service. Since most of the data services are delay-tolerant, the rejected data call can be queued until the loading conditions allow for this call to get admitted. The design and performance analysis of admission and load control policies for integrated services over CDMA have been previously studied and reported in the literature [e.g. 6–9].