Apple Inc.

Nortel Networks Corporation

Alan Darbyshire

Ricky Kumar Kaura

David Price

Matteo Candaten

Hock Gan

Stephen Bird

In an Internet Protocol Multimedia Subsystem (IMS) network in which multiple subscriber data servers are deployed with partitioned subscription data for users, a subscriber location function (SLF) is used to proxy queries to a subscriber data server (such as an HSS) in which subscription data for a user can be found. The SLF receives a query for the subscriber data server, looks up the address of appropriate subscriber data server and proxies the query to the appropriate subscriber data server. Preferably, the SLF is co-located with a subscriber data server.

Adaptable network service access through dynamic request routing

This invention relates to methods and apparatus for providing a resilient network database. The invention relates particularly, but not exclusively, to the IP Multimedia Subsystem (IMS). The invention is directed to an interface for a database node comprising: a port for receiving a request for information from a network node; a processor for determining if the database node can respond to said request; and a transmitter for forwarding the request to another database node if the particular database node cannot respond. The invention is also directed to a distributed database comprising a number of database nodes, wherein a request received by one node is forwarded to other nodes in the distributed database if the particular node cannot handle the request.

Resilient network database

Alternate home subscriber server (HSS) node to receive a request if a first HSS node cannot handle said request

A location register for a mobile communications network is coupled by an SS7 network for passing messages, has a mated location register at a different location to provide geographical redundancy, and has a status detector for detecting a status of the associated register, by sending a heartbeat message to the associated register. It deduces a fail if the message is returned by the signaling network. A cutover manager is arranged to enable a cutover on the basis of at least the detected status. By providing a more positive detection of a failure than merely passively interpreting a lack of response to the heartbeat, false triggering of cutovers owing to transient failures or temporary congestion, can be reduced. The cutover manager can verify the status by sending other messages by other routes, or using other criteria.

HLR mated-pair auto cutover

Growing community of inventors

Oxford, United Kingdom

Alan Darbyshire