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chank
2012-09-05, 11:21 PM
Dear all,

Do you know about ePLMN ? can share to me ?

:loveliness:

chank
2012-09-08, 12:14 PM
please share your experience or document, please. :-)

plannerguy
2012-09-09, 05:38 PM
Hi just sharing some results available in net,

understood that it is for having a smooth Packet service. i.e form GPRS TO 3G SERVICES.


EQUIVALENT PLMN


The purpose of ePLMN:
· Pan-European operators: Networks of the same operator in different countries should all be treated as a single HPLMN
· MVNOs (Mobile Virtual Network Operator) or Joint Ventures (like existing operators who want to share a 3G network)
· An operator that has different PLMN codes in 3G and 2G (to allow inter-PLMN cell reselection, and in particular GPRS to UMTS mobility)

A key 3GPP feature available to idle UEs is the “Equivalent PLMNs” mechanism. The Equivalent PLMN (ePLMN in this document) feature has been introduced in Spring 2001 within the 3GPP R99 specifications. It can be seen has an extension of the HPLMN concept to a set of PLMNs considered by the MS as equivalent (i.e. having the same priority) for network selection, cell reselection and handover. When a subscriber is moving to a cell with a different (but equivalent) PLMN Identity, the mobile will perform a Routing/Location Area Update on the new network instead of IMSI Attach. This will allow the successful transfer of any active PDP contexts to the new SGSN of the new equivalent PLMN as per normal RA update procedures.

Therefore ePLMN mainly allows:
· To support inter PLMN cell re-selection (cell reselection is natively an intra PLMN procedure)
· To maintain an active PDP context in case of GPRS to UMTS inter PLMN mobility


A list of ePLMN is sent to the MS by the MSC or SGSN, from the registered PLMN, at each Location Area Update, Routing Area Update and IMSI Attach procedures via a dedicated signalling connection. The list is thus provided as a dedicated message, the network does not broadcast it. Moreover, the ePLMN list is provisioned within the MSC and SGSN, i.e. it is not subscription information provisioned within the HLR. If no list is received during a LAU, RAU or IMSI Attach procedure, the former stored list (if any) is deleted by the MS.

The UE stores the ePLMN list on its SIM and derives the list of forbidden PLMNs (i.e. not part of the ePLMN list). While in idle mode, UE listens to SIB18 (if available) to receive the PLMN identity of neighbouring cells to be considered for cell reselection. The UE checks the SIB18 information and compare it with the forbidden PLMN list. Then the UE will measure only the neighbouring cells with PLMN IDs different from the forbidden PLMNs. Therefore SIB18 information will prevent UE from unnecessary measurements of forbidden cells.

If SIB18 is not supported (current UMTS-03 implementation at RNC), UE will listen to the broadcast channel of all neighbouring cells in order to decode theirs PLMN IDs, compare them with the forbidden PLMNs and decide which are the suitable cells for reselection.


Due to this extensive search, there could be some increase in cell reselection time and even call drop rate. This issue is under investigation.


Regards
preh

chank
2012-09-12, 05:27 PM
Hi,

thank, please share experience to setting or problem in network.

nupong
2013-02-01, 01:24 PM
Therefore ePLMN mainly allows:
· To support inter PLMN cell re-selection (cell reselection is natively an intra PLMN procedure)
· To maintain an active PDP context in case of GPRS to UMTS inter PLMN mobility



Does ePLMN play any role in Handover between inter-PLMN on the UMTS-UMTS?