1. - PON Architecture for Wireless Backhaul October 28, 2009 Paul Wilford

2. All Rights Reserved © Alcatel-Lucent 2009 2 | PON Architecture for Wireless Backhaul The mobile backhaul problem 1

3. All Rights Reserved © Alcatel-Lucent 2009 3 | PON Architecture for Wireless Backhaul The mobile backhaul problem Current Wireless Carrier Environment  Increased bandwidth demands  Due to more advanced users and handsets  Mobile broadband (killer app)  TDM Backhaul is not efficient for packet data  Doesn’t fit well in traditional T1 Architecture

4. All Rights Reserved © Alcatel-Lucent 2009 4 | PON Architecture for Wireless Backhaul The mobile backhaul problem Data is becoming the primary use of the network

5. All Rights Reserved © Alcatel-Lucent 2009 5 | PON Architecture for Wireless Backhaul 2005-20102010-20202000-2005 ARPU Traffic The mobile backhaul problem New mobile data services require exponentially increasing bandwidth but generate less revenue per bit transported than voice services.  100 Kb/s for GSM GPRS (downlink)  ≥100 Mb/s for LTE (downlink) This will break the traditional voice-optimized TDM Mobile Backhaul (MBH) network  Legacy leased line capex and opex scale linearly with bandwidth

6. All Rights Reserved © Alcatel-Lucent 2009 6 | PON Architecture for Wireless Backhaul Landscape of today 2

7. All Rights Reserved © Alcatel-Lucent 2009 7 | PON Architecture for Wireless Backhaul Landscape of today 3G1X HRPD IP Channel BTS Voice Channels DoRNC PDSN/HSGW GSM UMTS IP Channel Base Station NodeB Voice Channels Separate Core Networks for different Radio Access Networks SGSN – Serving GPRS Support Node GGSN – Gateway GPRS Support Node PDSN – Packet Data Support Node HSGW – HRPD Serving Gateway RNC – Radio Network Controller DoRNC – Data Optimized RNC BSC – Base Station Controller MSC – Mobile Switching Center HRPD – High Rate Packet Data (1xEV-DO) BTS

8. All Rights Reserved © Alcatel-Lucent 2009 8 | PON Architecture for Wireless Backhaul Landscape of today Examples of customer deployments – Customer ‘X’ Customer ‘X’ primarily uses ATM for backhaul. The overall strategy is to seek higher-capacity, lower-cost solutions as the more data-centric technologies such as HSDPA drive capacity requirements. The target state architecture is one that is flexible and can scale as capacity demand increases. Some solutions being considered include fiber to the cell site and bonded copper. Customer ‘X’ has a combination of GSM/UMTS networks and will need to integrate backhaul for all networks as it migrates from GSM to UMTS to LTE.

9. All Rights Reserved © Alcatel-Lucent 2009 9 | PON Architecture for Wireless Backhaul Landscape of today Examples of customer deployments – Customer ‘Y’ Customer ‘Y’s backhaul strategy consists of delivering Ethernet over the existing copper infrastructure with a migration to fiber-based Ethernet backhaul services. Customer ‘Y’ plans to leverage its Fiber to the Premise (FTTP) network with pseudowire to provide backhaul services.

10. All Rights Reserved © Alcatel-Lucent 2009 10 | PON Architecture for Wireless Backhaul Landscape of Tomorrow 3

11. All Rights Reserved © Alcatel-Lucent 2009 11 | PON Architecture for Wireless Backhaul Landscape of tomorrow – Evolution to a common core GSM UMTS IP Channel Base Station NodeB Voice Channels 3G1X HRPD IP Channel BTS Voice Channels DoRNC HSGW MME PCRF SGW PDN GW LTE RNC GSM and CDMA voice and data networks converge into an IP-based evolved packet core (EPC) For LTE, IP data from the eNodeB connects directly to the EPC BTS

12. All Rights Reserved © Alcatel-Lucent 2009 12 | PON Architecture for Wireless Backhaul Landscape of tomorrow - 4G/LTE Mission High Peak Data Rates 100 Mbps DL (20 MHz, 2x2 MIMO) 50 Mbps UL (20 MHz, 1x2) High Peak Data Rates 100 Mbps DL (20 MHz, 2x2 MIMO) 50 Mbps UL (20 MHz, 1x2) Improved Spectrum Efficiency 3-4x HSPA Rel’6 in DL* 2-3x HSPA Rel’6 in UL 1 bps/Hz broadcast Improved Spectrum Efficiency 3-4x HSPA Rel’6 in DL* 2-3x HSPA Rel’6 in UL 1 bps/Hz broadcast Improved Cell Edge Rates 3-4x HSPA Rel’6 in DL* 2-3x HSPA Rel’6 in UL Full Broadband Coverage Improved Cell Edge Rates 3-4x HSPA Rel’6 in DL* 2-3x HSPA Rel’6 in UL Full Broadband Coverage Packet Domain Only Simplified Network Architecture Packet Domain Only Simplified Network Architecture Scalable Bandwidth 1.4, 3, 5, 10, 15, 20 MHz Scalable Bandwidth 1.4, 3, 5, 10, 15, 20 MHz Network Co-existence UMTS, GSM, HRPD, CDMA Network Co-existence UMTS, GSM, HRPD, CDMA Low Latency < 5ms User Plane (UE to RAN edge) < 100ms camped to active < 50ms dormant to active Low Latency < 5ms User Plane (UE to RAN edge) < 100ms camped to active < 50ms dormant to active * Assumes 2x2 for DL in LTE, but 1x2 for HSPA Rel’ 6 Radio Access Network Core Network

13. All Rights Reserved © Alcatel-Lucent 2009 13 | PON Architecture for Wireless Backhaul Landscape of tomorrow – Technology Innovation With increased spectral efficiency, reduced latency and increased bandwidth, LTE enables innovations to improve performance at the handset. An example of this is CoMP.

14. All Rights Reserved © Alcatel-Lucent 2009 14 | PON Architecture for Wireless Backhaul What is CoMP? 4

15. All Rights Reserved © Alcatel-Lucent 2009 15 | PON Architecture for Wireless Backhaul What is CoMP? – Cooperative Multi-Point Controller High-speed backhaul All signals are potentially useful – no interference! Overcome inter-cell interference by coordinating Tx/Rx at several base stations, thereby greatly increasing user rates and system capacity. Each user is connected to several bases Desired signal Interference Data rates limited by interference Each user is connected to a single base Today’s network

16. All Rights Reserved © Alcatel-Lucent 2009 16 | PON Architecture for Wireless Backhaul What is CoMP? - System Outline Base Station CoMP Processor Backhaul that conveys both uplink and downlink baseband signal. Performs downlink and uplink CoMP beamforming. Base stations communicate with a centralized CoMP processor. The backhaul network conveys both uplink and downlink signals. Handset

17. All Rights Reserved © Alcatel-Lucent 2009 17 | PON Architecture for Wireless Backhaul What is CoMP? – Coherent vs. Non-Coherent  Coherent  Uses I/Q samples for CoMP processing in time or frequency domain  Requires the highest bandwidth from the backhaul network  Potential for greatest gain at the handset  Non-coherent  Uses soft bits for CoMP processing  Requires less backhaul bandwidth than coherent scheme

18. All Rights Reserved © Alcatel-Lucent 2009 18 | PON Architecture for Wireless Backhaul What is CoMP? – Uplink and Downlink  Uplink  To perform uplink CoMP, I/Q samples or soft bits must be transmitted to the CoMP processor  Downlink  To perform downlink CoMP there are two options:  Data and beam forming coefficients sent to each base station  I/Q samples or soft bits sent to each base station  After CoMP processing performed at CoMP processor  The backhaul network must support the required data distribution to all nodes  Channel State Information is required for beam forming  Different base stations adjust the amplitude and phase of the transmission of the signals to the handsets to achieve improved handset performance

19. All Rights Reserved © Alcatel-Lucent 2009 19 | PON Architecture for Wireless Backhaul What is CoMP? - Requirements CoMP schemes demand for  High bandwidth  multiple Gbit/s (DL &UL coherent, time domain)  <1 Gbit/s (DL & UL coherent, frequency domain)  about 100 Mbit/s (non-coherent)  Low latency  about 1 ms (all schemes, optimal case)  high backhaul latency may become a show stopper for CoMP –Need for a backhaul solution that is low latency The Technical challenge is to meet the latency requirement under fully loaded conditions. This requires sophisticated scheduling and MAC Layer processing.

20. All Rights Reserved © Alcatel-Lucent 2009 20 | PON Architecture for Wireless Backhaul Different PON technologies 5

21. All Rights Reserved © Alcatel-Lucent 2009 21 | PON Architecture for Wireless Backhaul Different PON technologies PON technologies:  APON – ATM PON  First PON standard – used primarily for business applications  622 Mbps/155 Mbps  BPON – Broadband PON  Extension of APON – added OMCI (OAM Management Control Interface) and WDM capability  622 Mbps/155 Mbps  GEPON/EPON – Ethernet PON  IEEE 802.3ah Standard  1Gbps/1Gbps  GPON – Gigabit PON  ITU-T G.984 Standard  Evolution of BPON  2.5Gbps/1.25Gbps

22. All Rights Reserved © Alcatel-Lucent 2009 22 | PON Architecture for Wireless Backhaul Different PON technologies PON technologies:  10G EPON – 10G Ethernet PON  Extension of GE/EPON  10 Gbps/1 Gbps  XGPON – 10G GPON  Extension of GPON  XGPON1 – 10 Gbps/2.5 Gbps  XGPON2 – 10 Gbps/10 Gbps  GPON is a suitable backhaul technology for packet-based services  For increased capacity and to support applications like CoMP, XGPON2 is the best backhaul solution

23. All Rights Reserved © Alcatel-Lucent 2009 23 | PON Architecture for Wireless Backhaul Synchronization 6

24. All Rights Reserved © Alcatel-Lucent 2009 24 | PON Architecture for Wireless Backhaul Synchronization: Problems with synchronization  Base station radio interface typically requires some level of synchronization  Frequency accuracy  Time/phase accuracy  Base station backhaul interface (typically legacy base stations) may be synchronous (T1/E1)  Synchronization considerations  Relative phase stability  Mobile hand-off between base stations  Coherent CoMP  Core network may or may not be synchronous  (Traditional) Ethernet, Synchronous Ethernet, SONET, etc.  Separate timing distribution network may or may not exist  GPS, NTR, etc.

25. All Rights Reserved © Alcatel-Lucent 2009 25 | PON Architecture for Wireless Backhaul Synchronization: GPON Mobile Backhaul End-to-End Synchronization OLT GPON RNC BSC RNC/BSC Gateway IP/ Ethernet Network GPON-fed cell site gateway (ONU) Cell site E1, Eth GPON PHY 8 kHz clockE1/Sync E PRC IEEE 1588v2 (when PRC not avail. at OLT) E1, Eth  The GPON Transmission Convergence (GTC) layer supports the transport of an 8 kHz clock via 125 microsecond framing  Therefore GPON provides deterministic synchronization like TDM  However, CoMP requires something better  To achieve more precise timing synchronization, provisions must be made to compensate for the OLT-ONU delay variations OLT ONU GPON frame t t t t

26. All Rights Reserved © Alcatel-Lucent 2009 26 | PON Architecture for Wireless Backhaul The MAC Layer 7

27. All Rights Reserved © Alcatel-Lucent 2009 27 | PON Architecture for Wireless Backhaul The MAC Layer: GPON  GPON QoS is maintained through transmission containers (T-CONTs)  T-CONT classes  Type 1 – fixed bandwidth  Type 2 – assured bandwidth  Type 3 – allocated bandwidth + non-assured bandwidth  Type 4 – best effort  Type 5 – superset of all of the above  Scheduling algorithm at the GEM Layer guarantees that transmission container bandwidth and latency guarantees are satisfied under fully loaded conditions  Dynamic Bandwidth Allocation  Maximum fiber bandwidth utilization  Based on queue status from ONUs  Security (via AES)  FEC

28. All Rights Reserved © Alcatel-Lucent 2009 28 | PON Architecture for Wireless Backhaul The MAC Layer: Backhaul challenges  CoMP data processed and sent to downstream path for scheduling/reflection to ONUs  Very low latency requirement of 1 ms  Handoff between eNodeBs requires tighter synchronization at base stations  OLT must send additional information to ONUs so they know neighboring ONU timing for handoffs  FEC at 10 Gbps  Completing R-S computations for 10 Gbps within 125 us is challenging

29. All Rights Reserved © Alcatel-Lucent 2009 29 | PON Architecture for Wireless Backhaul The MAC Layer: Scheduling for QoS and CoMP reflection CoMP processing. Data fed to downstream GEM Layer for reflection to ONUs S1/X2 translation 10G FEC decode 10G FEC encode CoMP timing messages

30. All Rights Reserved © Alcatel-Lucent 2009 30 | PON Architecture for Wireless Backhaul Conclusions 8

31. All Rights Reserved © Alcatel-Lucent 2009 31 | PON Architecture for Wireless Backhaul Conclusions XGPON2:  Is a backhaul solution that can accommodate growth in bandwidth demand  Is a backhaul solution that connects to the simplified network architecture  Is a backhaul solution that can integrate data from 2G,3G and LTE networks  Is a backhaul solution that can handle the uplink and downlink data distribution requirements for applications like CoMP  Is a backhaul solution that is synchronous and is compatible with IEEE 1588v2 synchronization through packet networks  Is a backhaul solution that contains efficient scheduling in the MAC layer for maintaining QoS under fully loaded conditions

32. All Rights Reserved © Alcatel-Lucent 2009 32 | PON Architecture for Wireless Backhaul Thank You!

33. All Rights Reserved © Alcatel-Lucent 2009 33 | PON Architecture for Wireless Backhaul Backup Slides

34. All Rights Reserved © Alcatel-Lucent 2009 34 | PON Architecture for Wireless Backhaul The MAC Layer: ONU block diagram

35. All Rights Reserved © Alcatel-Lucent 2009 35 | PON Architecture for Wireless Backhaul SHDSL.bis GPON 0,512 4 8 10 24 100 > 1000 500 1 DL Speed [Mbps] 2000200220042006200820102012 GPRS UMTS Wireless 10G PON ADSL ADSL2 Wireline HSPA Conclusions: Broadband Access Networks can support 3G/LTE Bandwidth Requirements LTE ADSL2+ VDSL2 HSPA+ GPON satisfies LTE bandwidth needs 2.5G DS/1.25G US shared Optical split adjusted as required. Future evolution to 10G PON (λ overlay on same PON) Bonded VDSL2 supports HSPA+ and early LTE ADSL2+ and SHDSL.bis are tactical solutions for 2G  3G XGPON2 satisfies LTE bandwidth needs 10G DS/10G US shared