20 Multiple Realms
23.2843GPPLocal Call Local Switch (LCLS)Release 17Stage 2TS
The principles for multiple IP realms shall be applied as defined in 3GPP TS 23.205 [2].
Annex A (informative):
Case studies for LCLS Negotiation
Annex A provides examples of LCLS negotiation in the CN and LCLS configuration in the BSS. The examples also illustrate optional isolation scenarios and the change of the initial set of preferences during LCLS negotiation.
A.1 oMSC LCLS-Negotiation handling when receiving UL bicast and sending DL data
Case study 1: If the oMSC server requires receiving UL data from the terminating UE and sending DL data to the originating UE then it shall perform one of the following:
– send LCLS-Negotiation (request) set to "LCLS-Not-Allowed" or;
– send LCLS-Negotiation (request) set to "Need_Receive Backward = Yes, Need_Send_Backward = Yes", set LCLS-Configuration IE to "connected both-way in the BSS and send access DL from the Core Network, block local DL" on the originating call leg (as shown in Figure X.1.1). If the BSS supports this configuration then LCLS will be allowed; otherwise LCLS will not be permitted.
NOTE 1: On the terminating leg the LCLS configuration IE is set to "connected both-way in the BSS and bi-cast UL to the Core Network" by the tMSC.
Figure A.1.1: oMSC requesting UL data from tUE plus sending DL data to oUE
Case study 2: If the oMSC server requires receiving UL data from the originating UE it shall either:
– send LCLS-Negotiation (request) set to "Need_Receive Forward = Yes" and set LCLS-Configuration IE to "connected both-way in the BSS and bi-cast UL" on the originating call leg after confirmation (as shown in Figure X1.2). If the BSS supports this configuration then LCLS will be allowed; otherwise LCLS will not be permitted. The data in the forward direction is passed to the tBSS due to the result of LCLS negotiation process on the originating call leg.
NOTE 2: On the terminating leg the LCLS configuration IE is set to "connected both-way in the BSS" if LCLS connection preference that is negotiated through the Core Network only requires UL data from the oUE as shown in Figure X1.2. For the requested LCLS configuration on the terminating call leg the tBSS does not expect to receive any user data from the Core Network but is specified to discard if received.
Figure A.1.2: oMSC requesting UL data from oUE indicated in LCLS-Negotiation
– In order to avoid the forwarding of the data in the forward direction to the tMGW the oMSC can send LCLS-Negotiation (request) to the succeeding node set to "Need_Receive_Forward = No" and if it does not receive "Need_Receive_Forward = Yes" in the LCLS-Negotiation (response) then it may configure its MGW to isolate the network side termination from the access side termination (as shown in Figure X.1.3).
Figure A.1.3: oMSC requesting UL data from oUE not indicated in LCLS-Negotiation
– If the initial setting "Need_Receive_Forward = No" is overwritten by a succeeding Core Network node and the oMSC server receives "Need_Receive_Forward = Yes" in the LCLS-Negotiation (response) then it shall configure its MGW to be bothway through-connected (as shown in Figure X.1.4).
Figure A.1.4: UL data requested from oUE by iMSC/tMSC, oMGW bothway through-connected
Case study 3: If the oMSC server receives a LCLS-Negotiation (response) set to "Need_Send_Backward = Yes" and "Need_Receive_Backward = Yes" (succeeding node of the oMSC server requires to send data to the oUE and to receive data from the tUE) then it shall perform one of the following:
– send an LCLS-Negotiation (request) set to "LCLS-Not-Allowed" or;
– set the LCLS-Configuration IE to "connected both-way in the BSS and send access DL from the Core Network, block local DL" on the originating leg (as shown in Figure X.1.5).
If the BSS supports this configuration then LCLS will be allowed and the requested LCLS configuration will be confirmed; otherwise LCLS will not be permitted.
NOTE 3: On the terminating leg the LCLS configuration IE is set to "connected both-way in the BSS and bi-cast UL to the Core Network" by the tMSC.
Figure A.1.5: iMSC requesting UL data from tUE plus sending DL data to oUE
A.2 tMSC LCLS-Negotiation handling when receiving UL bicast and sending DL data
Case study 1: If the tMSC server receives LCLS-Negotiation (request) with "Need_Send_Forward = Yes" and "Need_Receive_Forward = Yes" then it shall either:
– return LCLS-Negotiation (response) set to "LCLS-Not-Allowed" or;
– return LCLS-Negotiation (response) with value "Need_Send_Forward = Yes" and "Need_Receive_Forward = Yes" and set LCLS-Configuration IE to "Send Access DL, block local DL" (as shown in Figure X.2.1). If the BSS supports this configuration then LCLS will be allowed; otherwise LCLS will not be permitted.
NOTE 1: On the originating leg the LCLS configuration IE is set to "connected both-way in the BSS and bi-cast UL to the Core Network" by the oMSC.
Figure A.2.1: iMSC requesting UL data from oUE and sending DL data to tUE
Case study 2: If the tMSC server requires sending DL data to the terminating UE and receives LCLS-Negotiation (request) with "Need_Receive_Forward = Yes" and "Need_Send_Forward = No" during a LCLS negotiation request it shall either:
– return LCLS-Negotiation (response) set to "LCLS-Not-Allowed" or;
– set LCLS-Configuration IE to "connected both-way in the BSS and send access DL", return LCLS-Negotiation (response) with value "Need_Send_Forward = No" and "Need_Receive_Forward = Yes" and configure its Access MGW to isolate the network side termination from the access side termination when LCLS is established in order to avoid the forwarding of data from the oMGW/iMGW in the forward direction (as shown in Figure X.2.2), or;
NOTE 2: On the originating leg the LCLS configuration IE is set to "connected both-way in the BSS and bi-cast UL to the Core Network" by the oMSC.
Figure A.2.2: iMSC requesting UL data from oUE and tMSC requesting DL data to tUE: option isolate access side termination from network side termination
– return LCLS-Negotiation (response) with value "Need_Send_Forward = Yes" and "Need_Receive_Forward = Yes" and set LCLS-Configuration IE to "Send Access DL, block local DL" (as shown in Figure X.2.3). If the BSS supports this configuration then LCLS will be allowed; otherwise LCLS will not be permitted.
NOTE 3: On the originating leg the LCLS configuration IE is set to "connected both-way in the BSS and bi-cast UL to the Core Network" by the oMSC.
Figure A.2.3: iMSC requesting UL data from oUE and tMSC requesting DL data to tUE: option send Access DL, block local DL
Case study 3: If the tMSC server requires receiving UL data from the terminating UE and it receives LCLS-Negotiation (request) with "Need_Receive_Backward = No" (as shown in Figure X.2.4) during a LCLS negotiation request then it shall either:
– set LCLS-Configuration IE to "connected both-way in the BSS and bi-cast UL" and return LCLS-Negotiation (response) with "Need_Receive Backward = Yes" or;
– set LCLS-Configuration IE to "connected both-way in the BSS and bi-cast UL", return LCLS-Negotiation (response) with "Need_Receive Backward = No" and configure its MGW to isolate its access side termination from the network side termination in order to avoid the forwarding of data in the backward direction through the CN.
Figure A.2.4: tMSC requires DL data from tUE: option isolate access side termination from network side termination
Annex B (informative):
Change history
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Change history |
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Date |
Meeting |
TDoc |
CR |
Rev |
Cat |
Subject/Comment |
New version |
|
|
2011-03 |
CT#51 |
CP-110295 |
V2.1.0 approved in CT#51 |
10.0.0 |
||||
|
2011-06 |
CT#52 |
CP-110376 |
0001 |
– |
LCLS Handover Result Code update |
10.1.0 |
||
|
2011-06 |
CT#52 |
CP-110376 |
0002 |
1 |
LCLS Re-establishment Result Code update |
10.1.0 |
||
|
2011-06 |
CT#52 |
CP-110376 |
0003 |
1 |
LCLS Break Result Code update |
10.1.0 |
||
|
2011-06 |
CT#52 |
CP-110532 |
0004 |
1 |
LCLS Call deflection clarification |
10.1.0 |
||
|
2011-06 |
CT#52 |
CP-110376 |
0005 |
1 |
Update of Call Clearing and LCLS Break/Re-establishment |
10.1.0 |
||
|
2011-06 |
CT#52 |
CP-110376 |
0006 |
3 |
Update of Handover |
10.1.0 |
||
|
2011-06 |
CT#52 |
CP-110376 |
0008 |
1 |
Update of LCLS Call Establishment |
10.1.0 |
||
|
2011-06 |
CT#52 |
CP-110376 |
0009 |
2 |
Clarification of LCLS Configuration and LCLS Negotiation |
10.1.0 |
||
|
2011-06 |
CT#52 |
CP-110376 |
0010 |
2 |
Usage of option to isolate access side termination from network side |
10.1.0 |
||
|
2011-06 |
CT#52 |
CP-110376 |
0011 |
– |
Clarification of LCLS Configuration and LCLS Negotiation |
10.1.0 |
||
|
2011-09 |
CT#53 |
CP-110571 |
0012 |
– |
LCLS BSS Status update, call establishment clauses |
10.2.0 |
||
|
2011-09 |
CT#53 |
CP-110571 |
0013 |
– |
LCLS BSS Status update, LCLS break and re-establishment clauses |
10.2.0 |
||
|
2011-09 |
CT#53 |
CP-110571 |
0015 |
1 |
LCLS BSS Status update, Call Forwarding clauses |
10.2.0 |
||
|
2011-09 |
CT#53 |
CP-110571 |
0016 |
1 |
Clarification of LCLS negotiation and handling of tones or announcements |
10.2.0 |
||
|
2011-09 |
CT#53 |
CP-110571 |
0017 |
1 |
LCLS Configuration Applicability |
10.2.0 |
||
|
2011-09 |
CT#53 |
CP-110571 |
0019 |
1 |
LCLS Connect during Handover |
10.2.0 |
||
|
2011-09 |
CT#53 |
CP-110571 |
0021 |
– |
Update of mid-call announcement/tone examples |
10.2.0 |
||
|
2011-09 |
CT#53 |
CP-110571 |
0022 |
1 |
Negotiation of LCLS support |
10.2.0 |
||
|
2011-09 |
CT#53 |
CP-110723 |
0014 |
3 |
LCLS BSS Status update, handover clauses |
10.2.0 |
||
|
2011-12 |
CT#54 |
CP-110799 |
0023 |
3 |
LCLS Negotiation clarifications and correction |
10.3.0 |
||
|
2011-12 |
CT#54 |
CP-110799 |
0025 |
LCLS status update corrections |
10.3.0 |
|||
|
2011-12 |
CT#54 |
CP-110799 |
0026 |
1 |
Speech path restoration for LCLS break |
10.3.0 |
||
|
2011-12 |
CT#54 |
CP-110799 |
0027 |
1 |
Correction on IE descriptions for the LCLS Notification procedure |
10.3.0 |
||
|
2011-12 |
CT#54 |
CP-110799 |
0028 |
1 |
Correction on IE descriptions for the Handover procedure |
10.3.0 |
||
|
2011-12 |
CT#54 |
CP-110799 |
0029 |
1 |
Correction on IE descriptions for the Assignment procedure |
10.3.0 |
||
|
2011-12 |
CT#54 |
CP-110799 |
0030 |
3 |
Correction on Call Waiting procedure |
10.3.0 |
||
|
2011-12 |
CT#54 |
CP-110799 |
0032 |
3 |
Clarifications and rules for LCLS re-negotiation |
10.3.0 |
||
|
2011-12 |
CT#54 |
CP-110799 |
0033 |
1 |
Further corrections due to update to LCLS Connect during Handover |
10.3.0 |
||
|
2011-12 |
CT#54 |
CP-110799 |
0034 |
2 |
Re-specifying the naming for LCLS Negotiation and LCLS Re-Negotiation |
10.3.0 |
||
|
2012-03 |
CT#55 |
CP-120207 |
0035 |
5 |
Additional Control procedure during Inter-BSS Handover |
10.4.0 |
||
|
2012-03 |
CT#55 |
CP-120030 |
0036 |
1 |
Correction on general concepts for modification of LCLS configuration preferences |
10.4.0 |
||
|
2012-03 |
CT#55 |
CP-120030 |
0037 |
– |
Update of basic call examples |
10.4.0 |
||
|
2012-03 |
CT#55 |
CP-120030 |
0038 |
1 |
Update of call handover examples |
10.4.0 |
||
|
2012-03 |
CT#55 |
CP-120030 |
0039 |
– |
Update of service interworking examples |
10.4.0 |
||
|
2012-03 |
CT#55 |
CP-120030 |
0040 |
– |
Update of Mid-Call Announcement/tone examples |
10.4.0 |
||
|
2012-03 |
CT#55 |
CP-120030 |
0041 |
1 |
Introduction of LCLS Configuration Modification timer |
10.4.0 |
||
|
2012-03 |
CT#55 |
CP-120030 |
0042 |
1 |
Clarification of LCLS Connect_Control settings due to handover failure |
10.4.0 |
||
|
2012-09 |
CT#57 |
– |
Automatic update from previous Release version 10.4.0 (MCC) |
11.0.0 |
||||
|
2012-12 |
CT#57 |
CP-120724 |
0044 |
1 |
LCLS Negotiation Procedures |
11.1.0 |
||
|
2013-12 |
CT#62 |
CP-130641 |
0045 |
– |
GERAN Iu Mode |
12.0.0 |
||
|
2015-12 |
CT#70 |
– |
– |
– |
Update to Rel-13 version (MCC) |
13.0.0 |
||
|
2017-03 |
CT#75 |
– |
– |
– |
Update to Rel-14 version (MCC) |
14.0.0 |
||
|
2018-06 |
CT#80 |
– |
– |
– |
Update to Rel-15 version (MCC) |
15.0.0 |
||
|
2020-07 |
CT#90e |
– |
– |
– |
Update to Rel-16 version (MCC) |
16.0.0 |
||
|
2022-03 |
CT#95e |
– |
– |
– |
Update to Rel-17 version (MCC) |
17.0.0 |
||