1. Page 1 Control Plane Roaming LBS Roaming Meeting, San Francisco November 28, 2006 Revised Version Control Plane Roaming LBS Roaming Meeting, San Francisco November 28, 2006 Revised Version

2. Page 2 Control Plane Overview 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

3. Page 3 Control Plane Architecture and Interfaces Base Station LCS Client PDE MPC MSC / BSC MS E3 E12 E5 L1 HLR L2

4. Page 4 IS -881 Non-Roaming Call Flow

5. Page 5 IS-881 Registration (with MPCAddr)

6. Page 6 IS-881 Roaming Call Flow

7. Page 7 Issues with Control Plane Roaming Most operators Don’t comply entirely with IS-881 Use a “Roaming Service Provider” (RSP)

8. Page 8 Non-compliance with IS-881 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

9. Page 9 RSPs and CRXs 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

10. Page 10 Expected Control Plane Roaming Architecture RSP Home Operator Visited Operator MSC/VLR H-MPC HLR IS-41 Signaling HLR H-MPC V-MPC IP Network (L3) IP Network (L3) V-PDE LCS Client IP Traffic

11. Page 11 RSP Issue 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)

12. Page 12 RSP Issue Illustrated 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 RSP Home Operator Visited Operator MSC/VLR H-MPC HLR IS-41 Signaling HLR H-MPC V-MPC IP Network (L3) IP Network (L3) V-PDE LCS Client IP Traffic MSCID = RSP HLR MSCID = MSC/VLR RSP HLR = ?

13. Page 13 RSP Issue Solution #1 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) RSP Home Operator Visited Operator MSC/VLR H-MPC HLR IS-41 Signaling HLR H-MPC V-MPC IP Network (L3) IP Network (L3) V-PDE LCS Client IP Traffic MSCID = MSC/VLR Visited Op = 127.4.64.1 127.4.64.1

14. Page 14 IP Network (L3) IP Network (L3) RSP Issue Solution #2 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 RSP Home Operator Visited Operator MSC/VLR H-MPC HLR IS-41 Signaling HLR H-MPC V-MPCV-PDE LCS Client IP Traffic MSCID = RSP HLR MSCID = MSC/VLR IMSI maps to V-MPC

15. Page 15 Solutions to Issues 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