Femto-Cell Network Architecture Considerations

2. Femto-Cell Network Architecture Considerations Nortel October, 2007

3. Topics addressed • Generic Connectivity Requirements • Femto Architecture Options • PPP Termination • Tunnelled R-P • Tunnelled Abis • Tunnelled PPP • Considerations: • Femto-cell authentication and Security • Mobility/Seamless VoIP Handoff • Reuse of IOS interfaces • Protocols to use (P-P-like, PPP/ROHC session context transfer) • Accounting • QoS • Provisioning

4. Generic Connectivity Requirements AT Internet FEMTO 2 3 ISP 1 Border Router Security GW Cellular Provider Home Router (NAT) Cable /DSL Modem IPSec Tunnel PC • Reachability Requirements for Femtocell: • Femto must connect to the wireless provider access network in order to support mobility. There is a secure connection between the access network and the f-BTS • Internet breakout: Must have the possibility of local breakout for accessing internet (by-pass) • LAN access: Must enable access for the wireless device to devices on the local area network. • General Operation: • The Femto is connected by the customer to their existing home local network. An address is assigned to the local ETH interface with DHCP. • Femto ‘proxy clients’ can initiate WAN connectivity (IPSec tunnel establishment) to a wireless provider security gateway. • Ideally, the existing PDIF framework can be reused. Once the IPSec tunnels are established between Femto-cell and the PDIF, both Voice and Data traffic can be exchanged between the AT and the network.

5. PPP terminated at the FemtoCell – Data tunneled in IPSec tunnel to PDIF Mobility Mobile IP between PDSN and PDIF – not seamless Need data integrity solution to enhance HO (bicasting / fwd) Authentication Same as macro (CHAP or MIP) QoS Currently no solution – PDIF needs a Ty-like interface. Additional interface to f-BTS required. Local Breakout: Based on split tunneling. HRPD / 1x Data – Terminate PPP HA AAA policy New PDSN FHO PDIF New ISP RNC IPSec policy New HRPD BTS f-BTS HRPD SA = HOA DA = peer SA = HOA DA = peer MS

6. Local breakout – Reverse Link Each terminal is also provided a local IP address on the Local LAN. The NAT inserts the address as the SA field. Extract the IP frame from OTA encapsulation IP L2 Termination Classifier Local NAT ETH RAN Interface Encap. IPSec Forwarding requirements (looks at SA, DA) If DA = {internet, local lan} fwd to Proxy Client Else fwd to IPSec Encapsulate the IP frame in the appropriate RAN specific format WiMax : R6 (GRE) LTE : S1 (GTP)

7. Tunnel R-P interface between PDSN and f-BTS Scalability on legacy PDSN equipment Mobility Inter-RNC mobility – leverage cross-connectivity (A16/A17/A18/A19) Idle mobility (A13) Authentication Same as macro (CHAP or MIP) + A12 QoS Same as macro. Local Breakout Potential to support HRPD / 1x Data – Tunneled R-P HA AAA PDSN SEG R-P ISP RNC IPSec A12 A13 A16 A17 A18 A19 PPP HRPD BTS f-BTS HRPD MS

8. Tunnel A.bis between RNC and f-BTS Mobility Inter-RNC / Intra-RNC mobility may be possible Authentication Same as macro (CHAP or MIP) + A12 QoS Same as macro. No Local Breakout HRPD / 1x Data – Tunneled A.bis HA AAA PDSN SEG RNC BSC ISP RNC IPSec A.bis PPP HRPD BTS f-BTS HRPD MS

9. Tunnel PPP from AT via f-BTS to NAS/SEG Mobility Mobile IP between PDSN and NAS/SEG Authentication Same as macro (CHAP or MIP) QoS Currently no solution – possibility to leverage the PDIF framework. Local breakout Not possible HRPD / 1x Data – Tunneled PPP HA AAA PDSN NAS / SEG ISP IPSec (VPN) RNC L2TP HRPD BTS f-BTS HRPD MS

10. Femtocell QoS considerationsfor cable modem deployments • For cable modem deployments, it is desirable to leverage DOCSIS QoS capabilities, as defined by PC2.0 • For standalone femtocell, static QoS provisioning may be used, based on the DSCP marking applied by the femtocell (RL) and PDIF (FL) • For integrated femtocell, dynamic QoS provisioning can be used, through DSX signalling from an integrated cablemodem; classification would still be based on the DSCP marking applied by the femtocell (RL) and PDIF (FL)

11. Femto Service Considerations • Voice Feature Transparency • Full set of Originating & Mid Call services • e.g. Call restrictions, Caller ID blocking, 3WC, Call Hold, Call Waiting • Full set of Terminating services • e.g. Distinctive Ringing, Ringback Tones, Call Forwarding, Voice Mail with MWI, Selective Call Acceptance/Diversion, Anonymous Call Diversion, Do Not Disturb • Star Codes activation • e.g. Call Forwarding, Caller ID Blocking, Cancel Call Waiting, Local Star Codes • Regulatory services • LNP, E911, Lawful Intercept • Data Services Transparency • Leverages existing cellular packet data infrastructure to provide seamless transparency of existing data services • Billing and Back-office Integration • Same CDMA Billing format used • Common Fault and Performance management platform (CNM)

12. Femto Key Issues Considerations • Carrier IP access Vs Internet Access • Where is internet traffic segregated from carrier IP traffic? • Femto/Macro Handoffs - Like to Like Vs. Like to Different • 1x to 1x (Like to Like) has been the focus to date. • Expect Like to Different in the future. E.g. EVDOrA femto to 1x macro • Authentication & Authorization • Should 1x network AC be used to authentication of 1x homed femto users? • Where is femto authorization list kept, managed, etc. • QoE/QoS/Reliability • Back-haul n/w assumed to be outside of operators control. • Also question of QoS in the consumer LAN. RF coverage, Through-put/jitter, etc. • Capacity • How much capacity is required on the back-haul. • Is a new QoS capable WLAN AP needed to ensure throughput? • Directional HO • Single radio characteristics of 1x to 1x femto to macro demands network assistance. • Location / Location Based Services • Femto solutions need answer for location data. GPS, provisioned, … • Service Seamlessness • IMS based solution need to address issues with service seamlessness. • Regulatory – Licensed Spectrum – RF Interference, 911, CALEA,… • RF Spectrum / Macro Interference considerations.