US 8,509,148 B2Granted

System and method for application layer gateway assisted local IP access at a femto base station by network address translation

AssigneeIndustrial Technology Research Institute

InventorsStephan Gleixner, Jen-Shun Yang, Jui-Tang Wang, Shubhranshu Singh, Kuei-Li Huang

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Abstract

A method for application layer gateway (ALG) assisted local IP access (LIPA) at a base station by network address translation (NAT) allows IP capable UEs connected via HeNB or other kinds of Femto cell base station to use LIPA to establish multimedia session with other IP capable entities in the same IP network by NAT. The method relays a LIPA request to IMS, determines whether the terminating entity residing in the same IP network or not, and determines if the originating and terminating entities are allowed to use LIPA, and modifies the transport address information accordingly to facilitate signaling and packet routing. The method also provides the capability to apply different charging policies for LIPA and non-LIPA usages.

Claims16

Dependent claims

A method for application layer gateway (ALG) assisted local IP access (LIPA) at a base station by network address translation (NAT), applicable to a system having an IP multimedia subsystem (IMS), an originating entity, a terminating entity and a local network having an ALG and a Home eNode B (HeNB) having a NAT/Router/DHCP-Client module, said method comprising:

said IMS identifying a request from said originating entity for using LIPA, facilitated by NAT, to determine whether said originating entity is allowed to use LIPA, and if not, stopping said method;
when said terminating entity is in same local network as said originating entity, said IMS relaying that information of said originating and terminating entities residing in said same local network to said ALG, and said ALG changing transport address information (TAI) in said request response and TAI in an ACK message to a local TAI;
when in case of a handover situation, said ALG changing the TAI from said local TAI back to an original TAI;
and said IMS informing said originating entity that said terminating entity not being in the same local network and regular charging being applied or notifying to said originating entity to determine whether to proceed with a call setup when said terminating entity not residing in the same local network.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 12/980,539Filed 29 Dec 2010
Published: US 2012/0170512 A15 Jul 2012
Granted: 13 Aug 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification20 codes

H04L 61/2557
Translation of Internet protocol [IP] addresses: translation policies or rules
H04L 61/2514
Translation of Internet protocol [IP] addresses: between local and global IP addresses
H04L 61/2546
Translation of Internet protocol [IP] addresses: arrangements for avoiding unnecessary translation
H04L 65/1016
Architectures or entities: iP multimedia subsystem [IMS]