METHOD TO SHARE SIGNALLING LOAD BETWEEN RADIO ACCESS NETWORK CONTROLLERS IN A CELLULAR COMMUNICATION NETWORK

摘要

A Client/Server Cluster protocol runs at the interfaces between UMTS radio access network nodes (RNCs / eNBs) and an interconnecting IP backbone. The nodes are grouped together so as to form clusters of independent processing pool for signalling. The Cluster protocols is based on the following messages to implement its specific procedures: Processing Status: periodically exchanged among all nodes of the cluster to exchange information about the status of the internal processing resources. Processing Capacity Request: issued by a client node when its telephony processor is getting close to the congestion state. The aim is to request a target node having free processing capacity to take over processing of the incoming Layer 3 signalling relevant to new calls and/or packet data transmissions. The request message carries information on the status of resources controlled by the Client Node; this will allow the Serving Node to consistently take over their control if accepting the request. Processing Capacity Reject: issued by a Serving Node which can't accept a request. Processing Capacity Confirm: issued by a Serving Node which accepts a request sent by a Client Node. Rerouted Signalling: issued by a Client Node to allow the previously selected Serving Node to take over the RRC tasks for new calls or packet data transmissions on behalf of the Client Node. Rerouted Signalling is also issued by the Serving Node to redirect to the Client Node the outcome of the processing. Connection Setup or Connection Tear Down: issued by the Serving Node for controlling resources of the Client Node during the RRC processing on its behalf. Congestion Over: issued by a Client Node to the Serving Node, which will then release the processing resources accordingly (fig.11 ).