Dynamic dch allocation methodology for packet data services in a wireless communications system

Abstract

In a UMTS network, each packet data service user requires a dedicated channel (DCH) to transmit at high data rates. However, the number of DCHs available is small due to code and power limitations. Thus many users will have to be allocated the same DCH on a time sharing basis. Such sharing will not impact the quality of service for users whose applications are not delay sensitive and whose traffic generation pattern toggles between transmit and idle states. Such applications include web browsing, FTP sessions and E-mail. The present invention discloses four algorithms that can be used to dynamically allocate DCH channels to a contending user based on the user's need according to its traffic generation. One embodiment of the invention discloses a methodology of allocating user channels for packet data services in a wireless communications network, a first type channel having a given data rate and a second type channel having a lower data rate, including the steps of determining an estimated bandwidth requirement for the packet data services, switching a user to the second channel type from said first channel type if said estimated bandwidth requirement is below a first threshold, and switching a user to the first channel type from said second channel type if the estimated bandwidth requirement is greater than a second threshold. Another embodiment discloses methodology of allocating user channels for packet data services in a wireless communications network, a first type channel having a given data rate and a second type channel having a lower data rate, comprising the steps of providing an inactivity timer per user, and switching from the first channel type to said second channel type depending on a state of said inactivity timer.