Improving delivery time guarantees for wireless data services

The deployment of 3G cellular networks is ushering in a variety of data services in conjunction with the existing voice services. A major proportion of data services will include Web browsing and file downloads categorized as nonreal time services, for which there exists no service level agreement between the users and the providers on the quality of data services. In this paper, we address how to deal with the subjectiveness of user satisfaction or expectation from service providers by defining user irritation factors with the help of Sigmoid functions. These factors reflect users´ sensitivity and tolerance to delay. We propose a scheduling algorithm to provide a bound on the delivery time of the entire data content. This algorithm takes into consideration the dynamic nature of the irritation factors, channel conditions, user classes, and fairness within individual classes. Soft-reservation schemes are also proposed to cater to the higher paying users. Exhaustive simulations are conducted with synthetically generated HTTP traffic and three classes of users. Experimental results demonstrate that the proposed scheme is able to provide bounded delay even when the system utilization is as high as 80%.