LIPA was defined as part of Release-10 that I have already blogged about. Imagine the situation where a user started accessing local network while camped on the Home eNode B (aka Femtocell) but then moved to the macro network but still wants to continue using the local network. Release 12 defines this feature and is called Continuity of Data Sessions to Local Networks (CSN). This study item was originally part of Release 11 but has now been moved to Rel-12.
Basic functionality for Local IP Access (LIPA) has been specified in Rel-10.
LIPA signifies the capability of a UE to obtain access to a local residential/enterprise IP network (subsequently called a local network) that is connected to one or more H(e)NBs.
The current study item investigates extending LIPA functionality to allow access to the local network when a UE is under coverage of the macro network and provide related mobility support.
LIPA allows a UE to work with devices in the local network – e.g. printers, video cameras, or a local web-server. If the local network offers services that enable exchange of digital content (e.g. UPnP) LIPA allows the UE to discover supporting devices and to be discovered.
Examples for services that become available by LIPA are:
·The pictures stored in a UE’s digital camera may be uploaded to a local networked storage device or printed out at a local printer.
·A portable audio player in the UE may fetch new content from a media centre available on the local network.
·A UE may receive video streams from local surveillance cameras in the home.
·A local web-server in a company’s intranet may be accessed by the UE.
·Support of VPN.
LIPA does not require the local network to be connected to the Internet but achieves IP connectivity with the UE through one or more H(e)NBs of the mobile operator.
In Release 10 3GPP has only specified the support of LIPA when the UE accesses the local network via H(e)NB.
On the other hand an operator may, e.g. as a chargeable user service, wish to provide access to the local network also to a UE that is under coverage of the macro network. Access to the local network when a UE is under coverage of the macro network should be enabled in Rel-11.
In Rel-10 it had been required for a UE to be able to maintain IP connectivity to the local network when moving between H(e)NBs within the same local network.
However, access to the local network may be lost as a UE moves out of H(e)NB coverage into the macro network, even if other services (e.g. telephony, data services, SIPTO) survive a handover to the macro network and are continued. This may result in an unsatisfactory user experience.
The current study item will allow continuation of data sessions to the local network when the UE moves between H(e)NB and the macro network.
Therefore, in Rel-11, the 3GPP system requires additional functionality to allow
·A UE to access the local network from the macro network
·A UE to maintain continuity of data sessions to the local network when moving between a H(e)NB and the macro network
Objective: to propose requirements and study feasibility for the following scenarios:
Provide a capability to the mobile operator to allow or restrict
Access to an enterprise/residential IP network when a UE is under coverage of the macro network, assuming that the IP address of the local IP network (e.g. residential/enterprise gateway) is available to the UE.
Continuity of data session(s) to an enterprise/residential IP network when a UE moves between a H(e)NB in an enterprise/residential environment and the macro network.
The support of Continuity of Data Sessions to Local Networks should be an operator option that may or may not be provided by individual PLMNs.
The user should be able to decline access to the local network from the macro network. The user should also be able to decline continuity of data sessions to local networks when moving between H(e)NB and the macro network (e.g. in the case when data sessions to local networks is charged differently if accessed from macro coverage or via the H(e)NB).
A difference in QoS may be noticeable by the user when the local network is accessed from the macro network or via the H(e)NB.