Algorithmic Methods for Analysis of Integral Cellular Networks

Abstract

In the previous chapter, the second-generation cellular networks which are primarily concerned with single service class (voice traffic) communications were investigated. However, future generation wireless networks need to incorporate multimedia services (e.g., voice, video, data, etc.). In such networks all traffics (type of services) can be broadly divided into two types of real-time (such as voice, video transmission) and non-real-time (such as data transmission) services. In this chapter, models of integral cellular networks with real-time (RT) and non-real-time (NRT) calls are investigated. For easy reference here we define the RT calls as voice calls, while NRT calls are considered as data calls. In such networks four types of calls are distinguished: handover voice calls (hv-calls), new (or originating) voice calls (ov-calls), handover calls of data (hd-calls), and new (or originating) calls of data (hd-calls). The importance of these calls decreases in the above order. Voice calls (v-calls) are handled according to the pure loss scheme (i.e., the calls not accepted at the time of arrival are lost), and data calls (d-calls) are relatively tolerant to possible delays, i.e., they can wait in a queue of finite or infinite length. The access of heterogeneous voice calls is controlled by means of two-parameter state-dependent strategies, which limits the access on new and handover voice calls. Two schemes for buffering of data calls have been considered. In the first scheme only handover data calls can form a queue of finite and infinite length, while in the second one both new and handover data calls might be waiting in queue. In the second scheme the access of new data calls to buffer is restricted by means of state-dependent reservation scheme. Both methods for exact and approximate evaluation of the QoS metrics in such networks are developed. There has been also an investigation of the problems of choosing the required values of parameters for the introduced access strategies satisfying the given quality levels of servicing the heterogeneous calls. The results of comparative analysis of QoS metrics of the model under different access schemes have been presented. Results of numerical experiments are presented.