From CDMA Systems Capacity Engineering

To tackle the RRM issue in CDMA systems supporting multiclass traffic, in this chapter we propose a CAC scheme for CDMA systems supporting voice and data services and analyze the Erlang capacity under the proposed CAC scheme. Service groups are classified by their QoS requirements, such as the required BER and information data rate, and grade of service (GoS) requirements, such as the required call blocking probability. Different traffic types require different system resources based on their QoS requirements. In the proposed CAC scheme, some system resources are reserved exclusively for handoff calls to have higher priority over new calls. Additionally, queuing is allowed for both new and handoff data traffic that are not sensitive to delay. As a performance measure of the suggested CAC scheme, Erlang capacity is introduced. For the performance analysis, a four-dimensional Markov chain model is developed. As a numerical example, Erlang capacity of an IS-95B-type system is depicted, and optimum values of system parameters, such as the number of the reservation channels and queue lengths, are found. Finally, it is observed that Erlang capacity is improved more than two times by properly selecting CAC-related parameters under the proposed CAC scheme. Also, the effect of handoff parameters on the Erlang capacity is observed.

6.1 Introduction

Because future wireless applications will also be more bandwidth intensive and the radio spectrum allocated to wireless communication is hardly able to be extended, the CAC has become an essential network function of wireless networks supporting mixed services. Under a mixed-media...

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Topics of Interest

Overview In FDMA and TDMA systems, traffic channels are allocated to calls as long as they are available. Incoming calls are blocked when all channels have been assigned. The physical parallel in...

The maximum number of simultaneous users satisfying QoS requirements, a typical capacity definition in CDMA systems, should be evaluated in both single cell and multiple cell environments, as system...

Drs. J. Yang K. Kim In this chapter, we analyze the Erlang capacity of a CDMA system supporting voice and delay-tolerant data services and consider the characteristics of delay-tolerant traffic,...

Because the CDMA system is the interference-limited system, directional antennas are usually used for spatial isolation, which reduces interference. In a multisectorized cell using directional...

CABS Carrier Access Billing System CAC Call Admission Control CAC Card Authorization Center CAC Carrier Access Code CAC Connection Admission Control CAC Customer Administration Center CAD...