The introduction of new service categories with different bandwidth requirements, e.g., data and multimedia, to cellular mobile radio networks makes many of the traditional mechanisms for controlling traffic unusable or less efficient. The call admission and the handover handling are of the most sensitive issues in this extension to new services. The performance of all services including the traditional voice and the new services can be dramatically affected if appropriate schemes are not used. In this paper, we propose call admission and handover handling schemes for a cellular mobile network that offers two service types: voice and data. The data connections are assumed to transmit at different transmission rates that are integer multiples to that of one radio channel. In the case of congestion, the base station asks the active data connections to reduce their transmission rate in order to provide free channels for the newly arrived request of both service types. This is basically intended for incoming handover requests. The request will be rejected if the transmission rate of the active connections reaches a given minimum rate. Similar mechanism can also be used for new call arrivals, but some priority can be given to handovers by setting a higher transmission rate threshold for the new call rejection. As an extension to the proposed scalability, a queuing of new calls is also proposed and analyzed. Analytical models were built for the two proposed schemes together with the traditional channel reservation scheme. The effect of different traffic and configuration parameters on the performance measures like the grade of service, blocking probabilities, and utilization, are studied using the proposed technique. Results show that the proposed schemes provide very good performance and more fairness among the different service types.
ASJC Scopus subject areas
- Computer Science Applications
- Electrical and Electronic Engineering