Modelling service time distribution in cellular networks using phase-type service distributions

Third generation mobile communication networks are designed to provide a variety of high data rate services with higher quality of service (QoS) than second-generation systems. Handover becomes one of the major problems in such a mobile environment as it is of utmost importance to provide a higher guarantee that the users are able to continue their service during the entire length of the transmission, without it being blocked during the handover or loss of quality or data. Careful dimensioning of the network and the underlying teletraffic analysis plays a major role in determining the various grade of service (GoS) parameters that service providers can provide at various network loads. The channel holding time of a cell is one of the major parameters that needs to be accurately modelled in the teletraffic analysis. This paper focuses on using phase-type distributions of generalised Erlang form to model channel holding time in a mobile environment. We also present the quasi-birth-death process, which characterises the queuing models with generalized Erlang service and exponential inter-arrival distributions. Further we investigate the use of channels exclusively reserved for handover users to improve the handover performance.