SIP Based Architecture for Integration of 1xRTT Femtocells 2007 Tatara Systems Tatara Systems grants a free, irrevocable license to 3GPP2 and its Organizational Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner's name any Organizational Partner's standards publication even though it may include all or portions of this contribution; and at the Organizational Partner's sole discretion to permit others to reproduce in whole or in part such contribution or the resulting Organizational Partner's standards publication. Tatara Systems is also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner's standard which incorporates this contribution. This document has been prepared by Tatara Systems to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on Tatara Systems. Tatara Systems specifically reserves the right to amend or modify the material contained herein and to any intellectual property of Tatara Systems other than provided in the copyright statement above. 1
Outline Femtocell architectures SIP based architecture Voice Convergence Messaging Convergence Supplementary Services Handoff Scenarios 2
Network Integration Approaches (CDMA) 1 IOS Concentrator Modified MSC 2 IOS IOS-SIP SIP Soft MSC Mobile Core 3 SIP/IMS Convergence Server SIP/IMS Core 3
SIP-Based Femtocell Convergence Solution: Requirements Voice convergence Messaging convergence Supplementary services Emergency services Femto-macro handover Mobile Core Femtocell AP AAA Convergence Server Security Billing Voice/Data PDIF Voice/Data IP Core Security Gateway 4
SIP-Based Architecture: VoIP Core Mobile Core Convergence Server SIP-MSC IWF Acts as VLR and/or MSC to support IS41 MC MSC HLR SIP Client SS7 Femtocell AP IS-41 IS-41 AAA Convergence Server VoIP Core Broadband IPSec Wm SIP (RFC 3261) SIP (RFC 3261) Security Server 3GPP2 AAA Security Server Supports authentication of both femto and UEs. PDIF RTP Softswitch /MGCF MGW 5
SIP-Based Architecture: IMS/MMD Core Convergence Server Acts as AS with ISC interface to S-CSCF and Sh to HSS MC Mobile Core MSC HLR SIP Client SS7 Femtocell AP IS-41 Broadband IPSec AAA Wx HSS Cx Sh ISC Convergence Server IMS Core PDIF Wm SIP RTP x-cscf Mg MGCF Mn MGW 6
Authentication and Security 7
Security and Authentication Two steps for authentication Femto Each individual UE attached to Femto Femto is usually authenticated as part of the IPSec tunnel authentication step UE can be authenticated in one of two ways IPSec SIP/IMS 8
Authentication & Security in Femtocell Networks Femtocell & Device Authentication 3GPP2 AAA Security Server EAP-TLS, EAP-AKA, CAVE Authentication Variants Based on IPsec/IKEv2 Tunnel Authentication Authorization MS authorization Authorization for data services Billing/Mediation 3G Online/Charging Gateway generates CDRs Interfaces to standard mobile payment system: RADIUS, TAP3, IPDR, ASN.1, CSV Prepay EAP/ RADIUS/ DIAMETER Femtocell 3GPP2 AAA Server Wm PDIF Home Broadband Network LDAP IS-41 Wx DB HLR HSS IP Core Network 9
(1) Security and Authentication Solution: PDIF Tunneling PDIF AAA HLR/ AC Access Point Initialization AP IPSec ESP Tunnel Femtocell IPsec ESP tunnel to the PDIF via IKEv2 using standard EAP-TLS/AKA authentication with the TSS Circuit MS Initialization omt (RAND) Register (Key Mat.) MS IPSec ESP Tunnel UE specific IPsec ESP tunnel to the PDIF via IKEv2 using EAP to tunnel authentication CAVE/AKA with the TSS based on MS credentials Packet MS Initialization omt (RAND) Register (Key Mat.) MS IPSec ESP Tunnel UE specific IPsec ESP tunnel to the PDIF via IKEv2 using EAP to tunnel authentication CAVE/AKA with the TSS based on MS credentials Note: MS tunnels may be brought down after authentication depending 10 on the service
(2) Security & Authentication Solution: SIP Security PDG Convergence Server HSS/ HLR Femtocell Tunnel SIP Messages MAP Messages AP IPSec SIP Registration ESP Tunnel with Security UE Tunnel AP IPSec ESP Tunnel SIP Registration with Security UE Tunnel AP IPSec ESP Tunnel SIP Registration with Security 11
Voice and Messaging Convergence 12
Femtocell All-IP Convergence Solution: Operate in IMS and SIP based networks Mobile CS/PS Core PDSN MC MSC HLR Voice Convergence Supplementary Services Messaging Convergence Emergency Services Handover IS-41 WIN Convergence Server ISC, Sh SIP SIP Client Femtocell AP IPSec Broadband PDIF SGW HSMedia Gateway/ S Signaling Gateway MGCF X-CSCF MRFC MRFP VoIP Network IMS Core IMS Convergence MGW 13
Femtocell Voice Convergence: IMS MT call Femtocell HLR P/I/S-CSCF TCS MGCF MGW GMSC MS SIP Registration to HSS and 3rd Party to TCS with Location Update to HLR LOCREQ[MDN] IAM[MDN] ROUTREQ (MSID) routreq (IMRN) locreq (IMRN) HSS Derives AS Address from IMRN (Registered as PSI in HSS) SIP INVITE (IMRN) SIP 100 Allocate IMRN from Pool; Associate With MSID/MDN IAM (IMRN) SIP invite to Femto MS SIP INVITE (MSID) SBC SIP INVITE (IMRN) SIP 100 SIP INVITE (MSID) SIP 100 IMRN: IMS mobile roaming number RTP Audio through PDG CSRN: CS mobile roaming 14number
Femtocell Voice Convergence: IMS MO Call Femtocell HLR P/I/S-CSCF TCS MGCF MGW GMSC SBC MS SIP Registration to HSS and 3rd Party to TCS with Location Update to HLR SIP INVITE IFC Interaction With HSS SIP INVITE (MSID) SIP INVITE (MSID) Check for MO SS Check MT IFC Not a Femtocell Subscriber SIP INVITE (MSID) ISUP: IAM ISUP: ACM 180 Ringing 180 Ringing 180 Ringing Bearer Setup 200 OK ISUP: ANM 200 OK 200 OK RTP Audio through PDG 15
Femtocell SMS Termination P/I/S-CSCF Convergence Server MSC HLR MC 1. MS SIP Registration with Location Update to HLR Additional Steps if HLR does Not have temporary SMS routing address SMSREQ[MIN] smsreq[smsaddr] Incoming SMS (SMDPP) SIP: MESSAGE SMDPP[MIN] or SMPP Send SMS SMD-REQ SMD-ACK SMS Tunneled over SIP SIP: 200 OK SMS sent to Femto over SIP interface smdpp[ack] 16
Supplementary Services 17
Supplementary Services: Two categories Supplementary services support for services that required anchoring with existing mobile network infrastructure/elements, e.g., HLR, MC Setting up the Supplementary Service, e.g., call forwarding updates Specialized services For bearer services, two options: Direct support when no feature server is available Interaction with other SIP based feature server platforms as required (update the feature server based on femtocell registration) 18
Supplementary Services Application Server MC HSS/ HLR IS-41 Sh IS-41 Convergence Server FMC/IMS Application Server SS-Interworking Convergence Server Media Gateway/ Signaling Gateway ISC SIP SIP VoIP Network SIP/VoIP or IMS Core Control Normal Operation 19
Femtocell Handover 20
Voice Handover for Femtocells Convergence Server Support Handout (Femto Macro) and Handin (Macro Femto) of an in-session call on both SIP and IMS core. Capture usage information to enable appropriate charging Handover approaches Inter-MSC handoff, leveraging VoIP/IMS network VCC Adaptation: IMS anchored calls with the VCC AS (=TCS) providing handover through network initiated call leg establishment using inter- MSC handoff Note: Femtos have to support legacy handsets (single radio). VCC approach is defined for dual mode handsets, which are capable of terminating an insession call and re-establish a new call on its own to support handoffs. 21
Femto to Macro Handout: IMS network PSTN/ PLMN PSTN/ PLMN TCS TCS x-cscf MGCF x-cscf MGCF MGW MGW MSC PDG/PDIF MSC PDG/PDIF BSS Femto AP BSS Femto AP UE 22 UE data control
Femto to Macro Handout Tunneled over SIP Source MSC Target MSC Target BSC Convergence Server MSC RNC MGW MGCF Handoff required IS41_FACDIR IS41_facdir Handoff_Request Handoff_Req_Ack SIP INVITE HO Number IAM Handoff Cmd SIP Response ACM Handoff Commenced Path established Clear Cmd IS41_MSONCH Handoff Complete 23
Macro to Femto Handin (Anchored in Connected Domain) PSTN/ PLMN PSTN/ PLMN TCS TCS x-cscf MGCF x-cscf MGCF MGW MGW MSC PDG MSC PDG BSS Femto AP BSS Femto AP UE data control 24 UE
Macro to Femto Handin Tunneled over SIP Source MSC Source MSC Source BSC Convergence Server MSC RNC MGW MGCF Handoff_Request Handoff_Req_Ack Handoff Complete IS41_FACDIR IS41_facdir IS41_MSONCH Handoff required IAM ACM Handoff Cmd Handoff Commenced Path established Clear Cmd 25
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