Transcript Section 2: Section Title

Page 1
Control Plane Roaming
LBS Roaming Meeting, San Francisco
November 28, 2006
Revised Version
Control Plane Overview
Page 2
• Different LBS technology than the User Plane
• Uses the SS7/IS-41 network instead of packet data networks
• Control Plane defined in TIA/3GPP2 standards (IS-881/X.S0002)
• Standards include roaming architecture
• A few CP deployments out there, with a few more on the way
• Growing number of Control Plane enabled mobiles
• Control Plane roaming is important and seems straightforward
Control Plane Architecture and Interfaces
Page 3
HLR
L2
LCS Client
MPC
E3
MS
Base Station
E12
MSC / BSC
L1
E5
PDE
IS -881 Non-Roaming Call Flow
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LCS
Client
HMPC
HLR
HPDE
SMSC
MS
MLP SLIR (MDN,…)
a
LPREQ (MPCID, MDN,…)
b
lpreq (MSID, MPCAddr (serving), MSCID (serving), MPCAP…)
c
ISPOSREQ (MSID,…)
d
Paging / Traffic
Channel
Assignment
e
isposreq (MPCAP, MSCID, ServingCelID, MOBINFO,…)
f
GPOSREQ (MSID, MPCAP, ServingCellID,...)
g
IS-801 exchange
h
gposreq (POSINFO)
i
MLP SLIA (POSINFO,…)
j
IS-881 Registration (with MPCAddr)
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SMSC
VLR
HLR
MS
IS-2000 Registration
a
REGNOT (MSCID, MSID, MPCAddr,…)
b
REGNOT (MSCID, MSID, MPCAddr,…)
c
regnot (Profile,…)
d
regnot (Profile,…)
e
IS-881 Roaming Call Flow
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LCS
Client
HMPC
SMPC
HLR
SPDE
SMSC
MS
MLP SLIR (MDN,…)
a
LPREQ (MPCID, MDN,…)
b
lpreq (MSID, MPCAddr (serving), MSCID (serving), MPCAP…)
c
ISPOSREQ (MSID, MSCID (serving),…)
d
ISPOSREQ (MSID,…)
e
Paging / Traffic
Channel
Assignment
f
isposreq (MPCAP, MSCID, ServingCelID, MOBINFO,…)
g
GPOSREQ (MSID, MPCAP, ServingCellID,...)
h
IS-801 exchange
i
gposreq (POSINFO)
j
isposreq (POSINFO,…)
k
MLP SLIA (POSINFO,…)
l
Issues with Control Plane Roaming
Page 7
Most operators
• Don’t comply entirely with IS-881
• Use a “Roaming Service Provider” (RSP)
Non-compliance with IS-881
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• Operators have not implemented IS-881 entirely
• MPCAddr not delivered in REGNOT
• Operators using LOCREQ/SMSREQ instead of LPREQ from H-MPC HLR
query
• This avoids the need to upgrade the HLR
• IS-881 specifies L3 interface to use IS-41
• Operators have not implemented L3 interface yet
•
It is feasible to use an RLP-like IP interface instead of a standards based L3 interface
• H-MPC maps MSCID of MSC from LOCREQ/SMSREQ to IP address of V-MPC
RSPs and CRXs
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Roaming Service Providers (RSPs)
• Are in the business of facilitating roaming
• Provide an interconnection point for operators’ SS7/IS-41 networks,
•
settlement, and other value adds
Most operators use RSP services
CDMA Roaming eXchange Providers (CRXs)
• Facilitate packet data roaming
• Provide a central exchange point for IP data traffic, settlement and other value
•
adds
Most operators use CRX services
RSPs/CRXs: Aicent, Syniverse, VeriSign
Expected Control Plane Roaming Architecture
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Visited Operator
Home Operator
HLR
RSP
MSC/VLR
HLR
IP Network
(L3)
H-MPC
LCS Client
H-MPC
V-MPC
IS-41 Signaling
IP Traffic
V-PDE
RSP Issue
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• Most operators prefer to use RSP for roaming
• RSP provide peering point for SS7/IS-41 exchange
between operators
• RSP provides intermediary HLR function
• During registration, home operator receives generic
MSCID provided by RSP
• Home operator won’t be able to map generic MSCID to
correct V-MPC for L3 interface
• Also the message used on the L3 interface to invoke the V-MPC
needs to pass the serving MSCID to allow the V-MPC to execute local
IS-881 procedures (e.g., invoke the serving MSC)
RSP Issue Illustrated
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• MS registers, and RSP replaces MSC/VLR MSCID with generic RSP MSCID
• LCS Client queries H-MPC for roaming MS
• H-MPC uses LOCREQ/SMSREQ to receive MSCID (RSP HLR) from HLR
• H-MPC needs to map MSCID (RSP HLR) to the IP address of V-MPC
• Because MSCID is generic RSP MSCID, the H-MPC doesn’t know where the V-MPC is
Visited Operator
Home Operator
MSCID = MSC/VLR
RSP
HLR
MSC/VLR
MSCID = RSP HLR
HLR
MSCID = RSP HLR
RSP HLR = ?
IP Network
(L3)
H-MPC
LCS Client
H-MPC
IS-41 Signaling
V-MPC
IP Traffic
V-PDE
RSP Issue Solution #1
Page 13
• RSP provides the serving MSCID to home operator
• LCS Client queries H-MPC for roaming MS
• H-MPC uses LOCREQ/SMSREQ to receive serving MSCID from HLR
• H-MPC maps serving MSCID to the IP address of V-MPC
• H-MPC performs L3 transaction with V-MPC (passing serving MSCID)
Visited Operator
Home Operator
MSCID = MSC/VLR
RSP
HLR
MSC/VLR
MSCID = MSC/VLR
HLR
MSCID = MSC/VLR
Visited Op = 127.4.64.1
127.4.64.1
IP Network
(L3)
H-MPC
LCS Client
H-MPC
IS-41 Signaling
V-MPC
IP Traffic
V-PDE
RSP Issue Solution #2
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• MS registers, and RSP replaces MSC/VLR MSCID with generic RSP MSCID
• H-MPC always creates IP connection (L3) with RSP
• RSP maps MS IMSI in L3 messaging to V-MPC IP Address
• RSP connects to V-MPC (passing serving MSCID) and provides response to H-MPC
Visited Operator
Home Operator
RSP
HLR
MSCID = MSC/VLR
MSCID = RSP HLR
MSC/VLR
MSCID = RSP HLR
HLR
IMSI maps to V-MPC
IP Network
(L3)
H-MPC
LCS Client
H-MPC
IS-41 Signaling
V-MPC
IP Traffic
V-PDE
Solutions to Issues
Page 15
• Full IS-881 compliance (works with RSP)
• Non-compliant IS-881 deployment solutions
• Full interconnection (don’t use RSP)
• RSP solutions
– #1 - But pass serving MSCID (somewhat undermines the reasons for
using an RSP)
– #2 - RSP performs proxy of L3 interface
• L3 interface
• Use IS-881 standards interface
• Use RLP-like L3 interface