Patent ID: 6243363
Filing Date: 2001-06-05
Classification: H04L,H04Q,H04W

Abstract:
A method for transmitting user's cells from terminals to a switch stage of a local access network during a handover phase while a mobile unit is simultaneously in an area under coverage of two terminals,said network comprising terminals, concentration stages and a switch stage arranged in levels of hierarchy, means for linking said terminals to inputs of the concentration stages at a low hierarchical level and for linking outputs of the concentration stages at a high hierarchical level to said switch stage,means for identifying a VPI/VCI for each communication that is allocated to a mobile user's cells during a call phase,said method including the steps of:providing said network with servers associated with some of said concentration stages and said switch stage, said servers processing the flow of cells respectively emitted simultaneously by two terminals serving a coverage area in which a mobile unit is then located and for outputting one processed flow of cells,establishing a permanent virtual channel with a particular VPI identifier for each of said servers, anda plurality of steps carried out when a mobile unit already in communication moves into an area simultaneously served by two terminals of said network, as follows:determining the common server closest to said terminals,modifying the identifier VPI/VCI of the user's cells in the flows of cells emitted by said terminals, said modified identifier being the identifier of the permanent virtual channel of said determined common server so that cells emitted by both terminals can be processed in said server,and re-allocating the initial user's cells identifier VPI/VCI of the cells of the server output flow so that processed cells can be directed to said switch stage.