Feature #3831

BSC support for "network sharing" via MOCN

Added by laforge over 1 year ago. Updated 7 months ago.

Target version:
Start date:
Due date:
% Done:


Spec Reference:


This allows for RAN sharing between operators.

It includes
  • transmitting some new SI types on the BCCH (mainly SI22, optionally SI23 and SI21) to broadcast up to four additional PLMNs.
  • some additional signaling to select different operators' MSCs in the BSC in MOCN
  • some additional functionalty in a MSC if the MSC is shared in GWCN

Relevant top-level spec: TS 23.251

See also Interesting3GPPSpecsForDevelopers

Related issues

Related to OsmoBTS - Feature #4473: Support for broadcast of MOCN related SI21/22/23New03/29/2020


#1 Updated by laforge 7 months ago

The required functionality can be summarized as:
  • A interface connections to multiple MSCs (already required for e.g. MSC pooling as per #3682)
    • actually, each operator can have a MSC pool, so we have two dimensions of 'multiple connections'
  • generation of additional SYSTEM INFORMATION messages(SI22, SI23, SI21)
    • SI22 is the only mandatory part. SI23 is very complex and contains inter-RAT handover paramters for secondary PLNNs. SI21 contains access barring for them.
    • transmit them over Abis to BTSs
  • routing of MOCN-supported UEs initial access to respective operator ("PLMN index" in INITIAL L3 MESSSAGE)
  • routing of MOCN-unsupported UEs initial access to one operator
    • setting the "redirect attempt" flag in related messages to MSC
    • handle subsequent re-direction to other CN to other operotors
  • transmit PLMN-id of current core operator in SYSTEM INFORMATION on SACCH
  • handover needs to include PLMN identity in related messages

#2 Updated by laforge 7 months ago

  • Related to Feature #4473: Support for broadcast of MOCN related SI21/22/23 added

#3 Updated by laforge 7 months ago

  • Subject changed from BSC support for "network sharing" to BSC support for "network sharing" via MOCN

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