Patent ID: 6167248
Filing Date: 2000-12-26
Classification: H04W

Abstract:
A digital time-division cellular network having a plurality of mobile stations and base stations, at least one Base Transceiver Station (BTS) in each base station (BS) and connected via radio communications channels with at least one mobile station (MS), a base station controller (BSC) connected to at least one BTS, and a Mobile Switching Center (MSC) connected to at least one BSC, wherein radio channels between the mobile stations and the base stations comprise:a plurality of Traffic CHannels (TCH) for transferring speech and data between the mobile stations and the base stations; anda control channel in association with each of said TCH channels, said control channels comprising:a Random Access CHannel (RACH), for conducting signals from the mobile stations to the base stations requesting a TCH channel;a common Paging CHannel (PCH), for conducting a paging signal from a base station to a mobile station; andan Access Grant CHannel (AGCH), for conducting a signal from a base station to inform a mobile station of the TCH channel assigned thereto;and further comprising:a packet data service unit (Agent) coupled to one of a BTS, BSC, and said MSC, for connecting the cellular network to a data network;means for switching a mobile station to the Agent and signalling for the setting up of a connection to the data network;means in said mobile station and the Agent for storing a number of parameters relating to each other, said parameters including a Radio Link Protocol (RLP) and forming a virtual channel that provides a non-physical registration relationship between said mobile station and the Agent, using said parameters, and lacking a reserved path between said mobile station and the Agent preparatory to the establishment of a packet data transfer channel;means, responsive to a request from said mobile station to transfer or receive data packets, for assembling a packet data transfer channel between said mobile station and the Agent, making use of the parameters of the virtual channel, and wherein said packet data transfer channel comprises a first part comprising a radio channel between said mobile station and a base station to which the Agent is coupled and a second part comprising a time slot in a digital trunk line between said base station and the Agent;means for transferring data packets over said packet data transfer channel;means, responsive to the termination of data packet transfer over said packet data transfer channel, for disassembling at least said radio channel; andmeans for maintaining the virtual channel until the release of said mobile station from the Agent.