A performance evaluation approach for GSM-based information services

The ever increasing diffusion of mobile communications will lead to massive mobile access to the Internet. This paper focuses on the Wireless Application Protocol (WAP) for providing mobile information services, as envisaged by the Personalized Access to Local Information and Services for Tourists (PALIO) project within the fifth research framework of the European Commission. In particular, we consider a Global System for Mobile Communications (GSM) network where WAP traffic is transported by the Short Message Service (SMS) on specific GSM signaling channels. We develop suitable traffic models for both the WAP downlink traffic and the signaling traffic. An analytical approach is described that allows evaluation of the mean transmission delay of a WAP page. Finally, a downlink traffic scheduling policy is proposed in order to reduce the delay variance so that users experience a more regular traffic behavior (service usability requirement). The theoretical derivations shown in this paper for the GSM-SMS scenario are general and can also be tailored for other mobile communication systems. Such study allows dimensioning both the service and the downlink signaling traffic capacity in order to fulfill quality-of-service requirements for the users.