Bearer Network Solutions and Development Trend

1. Bearer Network Solutions and Development Trend

2. Outline • Discussion about Bearer Network Evolution Demand • LTE-Oriented Solutions • Bearer Network Development Trend

3. VoIP & Internet 2G/3G VIP dedicated line IP IP SAN Broadband access LTE IPTV Drive for Bearer Network Development Main service has switched to IP and new service development has accelerated. • Main business • PSTN is upgraded to NGN globally to achieve VoIP. • Traditional 2G BSs start to be converted to IP-based BSs in some high-end carriers. • The proportion of VIP IP-based dedicated line service has become larger and larger. The layer-2 VPN service is booming. • New business • The 3G network, such as mobile core network, and Backhaul, has entirely achieved IP-based services in version R5. The LTE deployment has started ahead of schedule. • The video services are booming. • The cloud-computing application and the IP-based storage services have grown rapidly. • Simplify network hierarchy and reduce TCO. • Make it easy to provisioning various types of new services to achieve an integrated service operation.

4. BTS Carrier-class protection ability less than 50ms Protect the service and network reliability High network security E2E service QoS, OAM and network management Clock and time synchronization Sound expandability meets the wireless network requirements at each phase and smooth evolution to protect the previous investment. Large-bandwidth/high-efficiency transmission PS-based switching Support for multi-service interface Adaptation to variation of bandwidth traffic and service flow. VIP dedicated line NodeB e-NB What Demands Should a Bearer Network Meet? E1 BSC/RNC MSC E1/FE • Advantage inheritance • Strategic demands • LTE-oriented • FMCtrend • Intelligent characteristics ？ SGSN FE/GE SR MGW GE aGW

5. RNC RNC MSCS MGW SGSN SGSN SGSN MGW MGW MGW SGSN RNC RNC RNC 3.84T 10G Core-layer Demand 1: Massive Bandwidth N×GE/2.5G POS BSC RNC BSC RNC RNC RNC RNC BSC RNC OTN MSTP/ASON • Demand: The enormous bandwidth required by the wireless access services (IP RAN, and Wimax), data service, IP-based 2G core network, and 3G networks stimulates the massive bandwidth demands. • The interfaces that link RNC with MGW and SGSN are mostly GE interfaces; moreover, RNC and MGW generally adopts dual-homing or Flex structure. • In future, with the growth of data services, the interface from RNC to SGSN will be upgraded to 10GE and RNC will also adopt a great number of Flex structures. • The port rate between the core router and the convergence router (switch) will be evolved to 10GE/10Gbit/s POS or even higher rate from GE/2.5Gbit/s POS. －MSTP/ASON is not capable of bearing the 3G core network services with the transmission capacity of only 10G. －OTN can provision the bandwidth of 3.84T, which can meet the bearing requirement of a core network in a short or long term.

6. Core-layer Demand 2: Simplifying Core Network Hierarchy MSCS MGW MGW SGSN MSCS MGW MGW SGSN RNC BSC BSC RNC RNC BSC BSC RNC MSTP/ASON OTN WDM • Demand: With the growth of bandwidth needed by the core network, the per-bit cost must be reduced. To simplify the network hierarchy is the first problem to be solved. －Routerover MSTP over WDM: This model adds the network hierarchy, which not only increases the network device investment and maintenance costs, but also makes the service scheduling more difficult. －Routerover OTN：The network hierarchy in this model is clearer and simpler; moreover, the ONT network is most suitable for the large-granularity service bearing and scheduling. To add a new node or change the original node less affects the network.

7. GE/2.5G POS 10GE/POS Core-layer Demand 3: High Efficiency, Flexibility, and Large Granularity • Demand：The bearing efficiency of TDM and IP services on the SDH/MSTP network is much low. A fully new network is needed to highly efficiently bear this type of service to solve this problem. After the IP-based 2G core network and 3G deployment, the core-layer scheduling will be shifted from STM-N to GE-above granularity. The large-granularity service needs to be scheduled uniformly. In a full-service operation, the bandwidth demands of various types of services are greatly different. The service traffic and the stream direction are indeterminate, meanwhile they take on an obvious mesh-like service flow. －For MSTP/ASONand the cross-grain of VC4, when the GE-above large-granularity packet service is scheduled, the cross resource will be greatly wasted and the scheduling efficiency is very low. －OTN devices are possessed with wavelength-class optical crossing and sub-wavelength-class electrical-laer crossing, which can increase the layers and grains of the service scheduling. －The Mesh network can be deployed based on ROADM and WSON, which ensures that the network expansion is more flexible and convenient, and provisions more flexible scheduling and bandwidth managemetn.

8. Router protection time is normally greater than 50ms RNC RNC MSCS MGW MGW MGW SGSN SGSN SGSN SGSN MGW RNC BSC RNC RNC RNC BSC RNC RNC … RNC BSC RNC RNC Core-layer Demand 4: High Reliability and High QoS • Demand: When the optical cable is faulty, it may arouse the logic links at several places of the data network to get faulty simultaneously. Then entire network is protected only depending on the IP network protection technology, which is difficult to meet the carrier-class protection demands of IP services. The optical-layer protection is the prerequisite to provide a less-than-50ms carrier-class protection. －A router can provide E2E service protection; the optical layer can provide protection for massive services at the physical layer. －Meanwhile, the router should be properly reloaded to increase the port bandwidth usage, thus to reduce the entire network investment. －OTN devices provide more abundant overheads than SDH, fully ensuring the E2E QoS service. －When the core network adopts the WSON technology and the Mesh structure, the service security will be enhanced, and meanwhile, the protection resources are saved greatly.

9. MGW RNC/BSC IP Bearer Network Evolution Trend 1. FMCmerging OLT Splitter Backbone network SR/BRAS Switch CR DSLAM PE IP MAN and Backbone network Backhaul SGSN/PDSN The future transmission network must be adapted to IP network merging-orientation, flattening, and large capacity. 2. Clustering routers • On the IP MAN core layer and the IP backbone network plane, the FMC trend is to bear the fixed network and the mobile network on one IP network, and to tends to merge and flatten networks. • The use of cluster routers simplifies the IP network hierarchy, and make the IP core and the backbone network oriented to the development of full interconnection and large capacity.

10. IP/MPLS Core BTV TG BRAS SR RNC BSC VOD Packet MW STM-1/ATM clock & phase MSTP/PTN/OTN CE/PTN MSTP/PTN MSTP/PTN SG • Perfect OAM • Service emulation • Clock synchronization • High-reliability assurance • Multi-service support • QoSassurance • Reducing per-bit costs VLAN Synchronized Ethernet IEEE 1588v2 E1 FE CE/PTN E1/TDM E1 nodeB E1/IMA BTS nodeB VLAN Convergence/Access Layer Demand 1: IP-based Mobile Service

11. Convergence/Access Layer Demand 2：Clock Synchronization • The existing transport network can only transmit frequency but cannot synchronize time. • In the existing time synchronization, a GPS receiving device is installed, which depends on the US GPS system, and thus the security problem may exist. • Home/indoor BS adopts network to transport sync information. TDM line + GPS

12. Convergence/Access Layer Demand 3: Full-Service Access Bearing

13. Outline • Discussion about Bearer Network Evolution Demand • LTE-Oriented Solutions • Bearer Network Development Trend

14. BTS BTS NodeB NodeB NodeB Bearing Demand Changes from 3G to LTE Tunnel Protection LAG RNC MSC SGSN BSC MSTPaccess ring MGW IP 3G MSTPconvergence ring 3G(non-IP) SDH Protection 2G 6300/6200 /6100 • Service flow has changed obviously • Opener structure • Diverse protection needs • Dramatic growth of bandwidth occupancy 9008 MSTP

15. NodeB eNB eNB eNB eNB Facing Future LTE Bearing Demands, Achieving Smooth Evolution CTN 6200 Tunnel Protection，FRR,ring protection FE RNC GE VRRP CTN 6300 CTN 9000 aGW CTN 6200 VRRP GE MME CTN 9000 VRRP GE aGW CTN 9000 GE IP 3G LTE X2 CTN 6000 CTN 6000 LTE S1 • LTE phase is the mobile super-broadband phase, which emphasizes that a network is flattened, the X2 service can be scheduled on the convergence-layer device, and the round trip should be reduced as much as possible. At the convergence layer and access layer, VRRP is stared to protect nodes and share loads. • eNB BS is connected to eNB and aGW in multiple directions, adopting Tunnel 1+1/1:1，ring or FRRp protection. PW and Tunnel support dynamic configuration. • For X2 MP2MP services, L2 VPN adopts VPLS mode, or IP/MPLS+L3 VPN.

16. MME MGW S-GW Residential Business BSC Mobile RNC SR BRAS ZTE PTN Series Products ZXCTN 9008 ZXCTN 6100 ZXCTN 6200 ZXCTN 6300 ZXCTN 9004 MAN core layer Access layer Convergence layer GE Abis STM-1/GE Iub STM-1/GE 10GE GE GE/10GE GE/10GE • Based on high-value services, such as Backhaul, and VIP service, achieves E2E entire network deployment. • Adapted to PTN standards development and new demands for future service network evolution by supporting software upgrade.

17. Exert Efforts to Push PTN Industry Development • In the Geneva ITU-T standards conference of Sep, 2009, the proposal of PTN Time Synchronization jointly raised by ZTE and China Mobile aroused great attention in industry. • In the forum of 2009Optical Communication and Bearer Network Construction, ZTE was awarded with “Promotion Prize of Optical Communication Industry Development in 2009 – PTN Industry Promotion Prize”, and the “Prize for Most Integratedly Competitive PS Transport Network Scheme Provider”, which complimented ZTE for its outstanding contribution in the field of PTN industry, and fully recognized ZTE PTN product and scheme. • Deep cooperation with global well-known carriers to push the PTN product into a wide commercial use

18. WSON PXC OTN i WDM L2 i WDM－All-IP Service Transport Platform of a New Generation • Compliant with all-IP service, compatible with traditional TDM service; a uniform transport platform of new and old services All IP orientation • All OTN • Meets the needs of scheduling IP service intelligently • Loads control planes High- Integrated Intelligent i WDM IP Intelligent • More compact device, less space occupancy • Environment friendly, low consumption, low radiation, and recycled material High integration i WDM integrates the OTN technology, PXC optical-layer scheduling, L2 switching, and WSON control plane to the same transport platform.

19. Channel-sharing protection Channel1+1 Line1+1 Reliable protection MESH protection+ recovery MESH recovery Multiplexing-segment sharing protection Subwavelength channel sharing protection Subwavelength1+1 Wavelength1+1 WSON Reliable protection MESH protection + recovery MESH recovery Wavelength channel sharing protection BoD GE/FE OVPN FC ZTE i WDMFunctions Perfect optical-layer and electrical-layer carrier-class protection L3 3D scheduling system Load WSON control plane Pollution reduction function Traditional WDM—80 wave： OTM OTM OLA iWDM—80 wave： Much less space occupancy

20. MAN convergence core Tandem MAN edge ZXMP M720 High integration, dense wave in one ZXMP M820 Multiplex flexible networking Intelligent scheduling ZXWM M920 Super distance, large capacity ZXONE 8000 Large-capacity, cross intelligent scheduling ZTE i WDM Family

21. NE-layer NM EMS Network-layer NM NMS Planning softwareZXTOP E2E QoS, unified NM and performance detection ZTE i WDM Family

22. Outline • Discussion about Bearer Network Evolution Demand • LTE-Oriented Solutions • Bearer Network Development Trend

23. Development Trend of Bearer Network • 2009: IP/MPLS + NGSDH + PTN • 2010-2013: IP/MPLS + ROADM + PTN + GMPLS + OTN • All optical network uniform control plane

24. MPLS Ethernet QoS Multicast PW ACL PTN PS switch Clock NM Protection switchover MSTP Hierarchical network structure OAM Next-Generation PS Transport Technology——PTN • PTN (Packet Transport Network) refers to an integrated transport technology which, taking a packet as a transmission unit, primarily bears carrier-class Ethernet services, and is compatible with the services like TDM, ATM, and FC. • Based on PS structure, the PTN technology inherits the MSTP concept, and merges the advantages of Ethernet and MSTP. It is a technology that suits the carrier-class PS bearing.

25. MPLS T-MPLS SDH like OAM/PS PBT Ethernet PTN Two Connection-Oriented PTN Technologies • T-MPLS：Transport MPLS T-MPLS is a PS transport technology developed on the basis of the MPLS technology and in combination withthe transport network characteristics. • PBT：Provider Backbone Bridge Traffic Engineer PBT is a PS transport technology developed on the basis of the Ethernet technology, and in combination with the transport network characteristics. T-MPLS = MPLS- Most L3 Complexity +OAM+PS PBT = MacInMac -Connenctionless+OAM+PS

26. Technological Comparison for IP-based Bearer Network Evolution PTNScheme ——TMPLS/MPLS-TP MSTP+Scheme ——MSTP upgrades to PTN, dual-plane

27. With the move-on of the IP-based BS and the growth of service bandwidth, perform PTN E2E networking in the hot areas (CBD centralized area, dense high-end communities). Bear the new 3G service on the new PTN network and cut the 3G service borne on the MSTP network to the PTN network. With the IP-orientation of the 3G service and the bandwidth growth, the PTN network has developed from the hot areas to the normal outlying areas. RNC 3G 3G 3G 3G 3G BTS BTS BTS PTN Introduction Purpose: To Establish E2E PTN Network GPS replacement for existing network verification BSC MSTP 2.5G Convergence layer PTN 10GE UNMS MSTP 622M Access layer PTN GE

28. RNC 3G 3G 3G 3G 3G BTS BTS BTS BTS BTS PTN Network Establishment Perspective (Evolution) Reduced number of TDM services, Widely applied PTN, Partly Heterogeneous Networking of MSTPand PTN Synchronous replacement of PTN-based GPS time BSC Convergence layer PTN ＋OTN UNMS FE/GE STM-16/4/1 PTN GE MSTP 622M Access layer Important group client FE • The TDM services are reduced. The MSTP expansion is reduced. PTN is deployed widely to bear mobile, VIP and some data broadband services. • A small number of interconnection scenarios exist in PTN and the local MSTP access layer. The interconnection service channel can be protected through LAG protection or MSP protection. • The MSTPnetwork and the PTNUNM are monitored in real time.

29. Smooth MSTP Evolution toPTN — Dual-Plane Analysis Application layer TDM Ethernet ATM PTN PTN PS switching Packet Transport MSTP MSTP Circuit switching TDM Transport • This is a transitional scheme. Its functions are limited and the lifecycle is short. • The so-called “smooth evolution” scheme is actually to upgrade the device to have the bearing capability with PTN features under the condition that the existing services remain unchanged. However, this upgrade is not thorough. The upgraded device is not a PTN device, but a heterogeneous device of MSTP and PTN. • MSTP and PTN networks are separately established. The services between two domains on the same device are transported through jumper fiber, which is equal to overlapping a PTN device on the previous MSTP node. • Currently , PTN independent device is at the verification stage. It takes more risks to the MSTP device that can be upgraded to PTN in the network recently.

30. Integrated with TDM and packet chips; TDM and packet services are processed separately. The interconnection between two planes are achieved by a jumper fiber. MSTP line card Packet line card Packet line card Mix cross board Mix cross board MSTP line card MSTP line card Main control board Main control board Fan Fan Packet processing parts MSTP processing parts Tributary Line vc switch E1,E3 C.STM - 16 TDM TDM SDH VC FE, GE Cross - connection C.STM - 64 VCAT TDM TDM FE, GE P.STM - 64 Packet Packet POS Packet based FE, GE 10GE Switch Fabric Packet Packet pkt switch Smooth MSTP Evolution toPTN——Device Function Analysis • To allocate a part of resources to the PTN plane to use, the original MSTP functions and performance will naturally be impacted. For example, after a PTN line card is added on the device, the uneven bandwidth distribution on the device backplane will greatly affect the original MSTP functions; while after a part of slots are inserted by PTN line cards, the MSTP function based on the even slots will not be performed. • 。The dual-bus deployment of TDM and Packet, in addtion to the PS coding mode, encapsulation, overheads, and acceleration ratio, cause the real access and switching capacity of PS in the dual-plane device to be far less than theoretical capacity. For example, for a 320G MSTP/PTN device, the PS switching capacity is less than 80G in real application. • Because the services between MSTP and PTN domains are transmitted through jumper fiber mode, it increases the data processing delay and the fault points, which is not compliance with the E2E concept. The alarms between the MSTP plane and the PTN plane are terminated before the service interconnection, and cannot be transmitted mutually. Even if the alarm transmission problem was solved by some special internal technical measure, the interconnecion with other manufactures’ network cannot be implemented due to the lack of corresponding standards support.

31. Smooth MSTP Evolution toPTN—Analysis on Device Upgrade Acts Application layer Application layer TDM Ethernet ATM TDM Ethernet ATM Circuit switching Upgrade Circuit switching TDM Transport Circuit switching TDM Transport Packet Transport Cross（circuit switching kernel） Cross（circuit switching kernel） Replace Replace Line card（TDMprocessing: overhead/encapsulation Line card(packet processing: QOS/OAM…) Replace Power module（support for low power consumption） Power module（support for higher power consumption） Replace Software logic（TDM service and device control) Software logic（packet & TDM service and device control) Limited function Backplane（suitable for bus design of TDM backplane） Backplane (care for backplane bus design requirements of packet & circuit) 平滑升级 Upgrade process unsmooth

32. Tributary Line vc switch E1,E3 C.STM - 16 TDM TDM FE, GE P.STM - 64 SDH VC Packet Packet POS FE, GE Cross - connection C.STM - 64 VCAT TDM TDM FE, GE 10GE Packet Packet FE, GE P.STM - 64 E1,E3 Packet Packet POS CES Packet based pkt switch FE, GE 10GE Switch Fabric Packet Packet Packet based Pure PTN Switch Fabric pkt switch Procedure of Upgrading MSTP to PTN Tributary Line vc switch E1,E3 C.STM - 16 TDM TDM SDH VC FE, GE Cross - connection C.STM - 64 VCAT TDM TDM (1) Replace crossboard, and add packet processing board Pure MSTP MSTP+ (2) ALL IP-orientation. TDM gradually recedes TDMservice board decreases. (3) TDM bus is no longer used. Replace the crossboard again? Fake PTN vc switch SDH VC Cross - connection - 64 FE, GE P.STM - 64 Packet Packet POS Packet based FE, GE 10GE Switch Fabric Packet Packet E1,E3 CES MSTP+ pkt switch

33. MSTP+Upgraded to PTN VS. New PTN Establishment

34. NRZ ODB DPSK DQPSK PM QPSK 40G DWDMKey Technology——Modulation Mode

35. 40G Modulation Technology Comparison The currently primary commercial modulation technologies are ODB/PSBT and DPSK. To achieve RZ DQPSK PM QPSK, its technology is complicated and costly.

36. DP-QPSK Dual-polarization quadriphase shift keying CSRZ-DQPSK can only realize the spacing of 100GHZ, and cannot realize the spacing of 80 waves*50GHZ same as that of the heterogeneous deployment of the existing network, 10G, and 40G. OPFDM-DQPSK Polarization OFDM-DQPSK oPDM-DQPSK Optical pulse breadth modulation- DQPSK ePDM-QPSK Electrical pulse breadth modulation- QPSK DPSK-3ASK (Differentiate phase shift keying – 3-phase shift keying) modulation mode to achieve the serial transmission of 100Gbps of the single-wave channel … 100G Modulation Technology 40G/100G technology mainly focuses on which modulation technology to select The selection of technology depends on PMD tolerance, transmission distance, and signal channel spacing (50G/100GHz).

37. The entire optical layer of OTN is classified into: Optical channel (OCh), optical multiplex section (OMS), and optical transmission section (OTS) OCh is also classified into three sub-layers: Optical channel data unit (ODUk), optical channel transmission unit (OTUk), and optical channel sub-layer Backbone/MAN Core - OTN IP、ETHERNET、 ATM、SDH/SONET Client layer Optical channel payload unit（OPU） 3 electrical-domain sub-layers Optical Channel layer network （OCh） Optical channel data unit（ODU） Optical channel transmission unit（OTU） Optical channel OCh Optical Multiplex Section layer network （OMS） Optical domain Optical layer Optical Transmission Section layer network （OTS）

38. Backbone/MAN Core -ROADM WSS Multi-degree ROADM The MEMS-based WSS is an inevitable choice for high-dimensionality ROADMtechnology.

39. MAN: T-MPLS/MPLS-TP • Client equipment • Carrier equipment (IP DSLAM, Ethernet Switch, IP/MPLS router) • Other carrier equipment • Any client-side service • Ethernet • IP/MPLS • T-MPLS (Carrier – carrier service) • ATM, frame relay, L1,- QoS management at each layer T-MPLStechnology standard T-MPLSnetwork structure T-MPLS = MPLS- Most L3 Complexity +OAM+PS

40. MAN-PBT PBBEncapsulation mode PBTnetwork structure • IEEE • 802.1ag Connectivity Fault Management-complete 2007 • 802.1ah Provider Backbone Bridge-complete 2008 • 802.1aq Shortest Path Bridging-complete 2009 • 802.1Qay Provider Backbone Bridging-Traffic Engineering-complete 2008 • 802.3ah Ethernet Link OAM TMF (TeleManagement Forum) • MTOSI work effort is PBT for OSS (Multi-Technology Operations Systems interface) ITU-T • G.pbt in SG15/Q12 living list • Y.1731 OAM incorporates PBB-TE features • G.8031 PS coordination IETF • GMPLS for PBT PBTTechnical Standards PBT = Mac In Mac – Connenctionless + OAM + PS

41. MAN-EoMPLS Point to Point, Metro Ethernet Service ISP C MPLS Network ISP A Enterprise LAN ISP B PE PE ISP 2 PE PE ISP 1 PE PE Enterprise LAN ISP 3 EoMPLS = MPLS–Partial L3 Complexity +OAM+PS

42. Pure data RPR Simple topology, difficult ring-spanning service No connection-orientation, Unable to achieve E2E Enhanced Ethernet No connection Enhanced protection ESR/ESS OAM that is hard to achieve traffic engineer and specific services MAN- Other Technologies

43. Control Plane • Symbol of an intelligent dynamic network — Control Plane • SDH+ control plane =ASON (RSVP-TE, OSPF-TE) • WDM+ control plane =WSON (RSVP-TE, OSPF-TE) • The IP/MPLS data network is born with control plane(RSVP,LDP,BGP,MP-BGP, supporting TE mode) • The future NG bearer network needs a uniform control plane. • Control plane GMPLS

44. Technical Summary

45. Evolution Route for Bearer Network Technology and ZTE Product Series 1 MPLS ZXR10 M6000 ZXR10 T8000 … ETH RPR ZXMP S150/200 ZXMP S320 ZXMP S325/330 ZXMP S380/S390 ZXMP S385 ZXCTN 6X00 ZXCTN 9004/8 ATM PDH PBT MPLS-TP SDH MSTP P-OTN OTH ZXONE 5xxx WDM ROADM PXC Fiber WDM ULH WDM 1990 1995 2000 2005 2010

46. Evolution Route for Bearer Network Technology and ZTE Product Series 2 MPLS ETH RPR iWDM ZXWM M920 ZXMP M820 ZXMP M720 ATM ZXMP M800 ZXMP M820 PDH PBT MPLS-TP ZXWM M900 ZXMP M800 ZXMP M600 SDH MSTP P-OTN OTH WDM ROADM PXC ZXONE 5X00 Fiber WDM ULH WDM ZXMP M900 ZXMP M920 1990 1995 2000 2005 2010

47. MGW/GGSN MSCS Core network access control BSC RNC PON General Perspective of Full-Service Bearer Network Operation IP dedicated network /MDCN CMNet+ Backbone Network MAN Backbone Network Core layer CR CR WDM/OTN Service access control layer Radio access network control SR BAS SR MAN convergence/access layer Metro_E PTN Bear high- bandwidth- need service Bear high-value service Switch xDsl VPNline VIP BTS eNB Public client NodeB Public client plane Important client plane

48. VIP line NodeB NodeB Broadband access Unified PTN Bearing Scheme (Small-Scale Network) Access In towns Aggregation In counties PTN RNC BSC SGSN BRAS SR PTN MGW PTN Pico/Femtocell PON OLT OTN Femtocell DSL • Under a circumstance of small entire business, PTN achieves the uniform bearing of the fixed network broadband and the mobile services at the convergence layer. • Scenario：In the areas where OTN is not covered, or hard to extend, it is the best solution to access PON and VIP with PTN.

49. CMNet OLT OLT ODU ODU ONU ONU Full-service convergence area Full-service convergence area 3G 3G Overall Structure of Full-Service Operation by Joint PTN/iWDM Networking Core equipment room RNC RNC RNC RNC PTN Router Core router iWDM Core node iWDM OTN,WSON SR/BRAS Backbone node GEoptical interface Convergence layer (iWDM sinks OLT nodes to solve the fixed network service operation bearing.) PTN bears high-value services. 10GE PTN Convergence ring iWDM Convergence node GE PTN Access ring FE Important group client FE • iWDM sinks to the convergence node to achieve the PON upstream bearing, which conforms to the future evolution trend of the PON technology. • The core-layer iWDMand PTN jointly achieves the TD bearing scheduling to increase the network flexibility.

50. The service packet evolution brings the revolution of the bearer network technology. Evolution form 2G to 3G IP RAN FMC MSTP PTN P-OTN P-OTN is a solution in the process of network IP orientation. Its drive comes the merger of multiple layers networks and network flattening.