ZTE´s Fixed Access Network Solution

In the Next-Generation-Network (NGN) ear, "the last mile" is still most argumentative portion of the telecom network. It occupies most of the total investment and provides complex technology scheme of the access network? This question of "the last mile" is stil the focus of the telecom industry. ZTE Corporation has launched its fixed access network total solution "Fiber-to-the-world" to satisfy the requiremetns of the operators.

1 ZXA10-MSAN System
The ZXA10-MSAN system, an integrated multi-service access network based on IP technologies, is an important part of the Fiber-to-the-World solution. The system adopts the IP+TDM multi-service bus structure and fully meets the requirements of telecom operators. For construction of broadband and narrowband integrated systems, ZXA10-MSAN is able to migrate to the NGN, and provide a convenient, prompt and economical network construction model. Therefore, it helps improve the network competitiveness.

    In addition to providing conventional narrowband voice and broadband data services for users, the ZXA10-MSAN system offers means of broadband access such as Asymmetric Digital Subscriber Line (ADSL), Very-high-bit-rate Digital Subscriber Line (VDSL) and Ethernet. These access ways can satisfy the diversified service requirements of different users.

    ZXA10-MSAN supports transmission by the existing transmission networks such as SDH, IP, ATM and MSTP networks. In addition, the system has a built-in integrated service-dispatching module to provide more reliable and more efficient networking functions. Therefore, it better adapts to different network situations, allows quick network construction and provides means of user access.

    As an NGN oriented access network system, ZXA10-MSAN has the powerful dual-homing ability to connect the Public Switched Telephone Network (PSTN) and the NGN. That provides the clients of the company with greater flexibility when they construct their fixed-line networks. In addition, when they upgrade their networks to the NGNs, the system helps lower risks of their investment. The ZXA10-MSAN is therefore becoming the first choice for many operators constructing their fixed-line networks. Figure 1 illustrates the ZXA10-MSAN dual-homing ability.
As shown in the diagram, via the ZXA10-MSAN PSTN-NGN dual-homing solution, operators can deploy the NGN network in the following steps:

    (1) At the beginning of the NGN construction, telecom operators might not have experience on the Softswitch system in a number of aspects, such as networking mode, processing capacity and system maintenance. At the same time, at the PSTN narrowband switches at numerous sites are still in service, therefore, the ZXA10-MSAN can connect these switches via V5 interfaces.

    (2) Meanwhile, the NGN surely becomes the main service platform in the future, therefore, the Softswitch-based trial office will be launched in some MSAN Optical Network Unit (ONU) sites via H.248 interfaces.

    (3) It will take a long time to complete the IP network construction, therefore, in some places where the IP backbone is not available, ZXA10-MSAN can connect the NGN network via the trunk gateway ZXMSG 7200.

    (4) When operators finish the IP network construction and get enough experience in running the NGN network, ZXA10-MSAN can be upgraded to ZXMSG system and all the things will be merged into the NGN network.

2 ZXMSG System
Fully considering the system compatibility, ZTE´s ZXMSG 5600/5200 products inherit the ZXA10-MSAN system design philosophy, sharing the same hardware platform with the MSAN relevant product series. Thus, ZXMSG access solution can fully protect the operator´s prophase investment for the network construction.

    For operators, there are two choices to deploy the ZXMSG system: one is to upgrade the ZXA10-MSAN system and the other is to deploy ZXMSG system directly. In addition, for those operators who want to build pure NGN directly, the ZXMSG system is the best multi-service access solution.

    The ZXMSG is not only able to access Softswitch networks via H.248, but also to provide a number of highly efficient broadband service access methods such as Digital Subscriber Line (DSL) and Ethernet technology. The ZXMSG products also can provide built-in EPON/GPON modules to support Fiber to the Home (FTTH) and allow users to truly experience the magic of optical communication in the NGN age. Figure 2 shows the typical topology of
ZXMSG system.

3 ZXPON System
ZTE´s ZXPON passive optical network system is initiated for construction of a
new-generation optical access network in accordance with the increasing bandwidth requirements of the access layer, three-in-one solution, triple-play service and the leading trend from core networks to IP-based NGN networks. The goal is bringing all the techniques at diversified developing levels together such as EPON, GPON, Ethernet and xDSL.

    As an integrated optical access solution, the system comprises the central office equipment varies in capacities and the serialized subscriber equipment capable of various applications like FTTC/B/O and FTTH/P.  It helps operators easily conduct services with cost-effective broad bandwidth and multi-service capabilities to cope with the severe competition, rapidly developing services and ceaseless network evolution.

    The ZXPON passive optical network system provides excellent multicast and dynamic traffic scheduling capabilities. In addition, it supports broadband data and Internet access services, VoIP, IPTV, CATV video frequency services and L2VPN services. Moreover, it satisfies access requirements in expanding high broadband services such as interactive VOD/IPTV/SDTV/HDTV and boasts reliable QoS and security guarantee. Working with ZTE´s integrated services access network ZXA10-MSAN and integrated service access gateway ZXMSG 5200/5600, the ZXPON passive optical network system provides customers with a full series of FTTx solutions. Figure 3 shows the typical topology of ZXPON system.

4 Serving the World
After years of competition in domestic and international markets, ZTE has accumulated extensive experience in the area of access networks. The ZXA10-MSAN is now widely used in markets around the world including Asia, Africa and Latin America. Furthermore, in the evolution of PSTN towards NGN, thanks to its unique dual-homing capabilities, the ZXA10-MSAN is even more appealing.

4.1 ZXA10-MSAN Building PTCL´s OFAN in Pakistan
PTCL is the largest carrier of Pakistan, it is the intention of the PTCL to progressively deploy Optical Access Network to provide narrowband and broadband telecommunication services to its customers.

    With many advantages in multi-service capability, FTTx networking ability, PSTN-NGN dual-homing ability and Triple-Play aspects, ZXA10-MSAN has already caught more operator´s eyes and is becoming the most popular choice for access network constructing day by day.

    Fully considering the requirements, PCTL investigated a number of access network system in the market and at last decided to deploy ZTE multi-service access network ZXA10-MSAN.

    Till Q1, 2005, as the main access equipment provider, ZTE has already deployed about 440 000 lines
ZXA10-MSAN system for PTCL´s OFAN (including phase I and phase II). The services includes POTS (Photo-Optical Terrain Simulator), ISDN (Integrated Services Digital Network), ADSL/2/2+, Ethernet, DDN (Digital Data Network), and more.

    Figure 4 shows the application of ZXA10-MSAN in Pakistan´s PTCL.

4.2 ZXA10-MSAN Building Integrated Optical Access Network in Indonesia
In 2004, ZXA10-MSAN won a contract from Indonesia Telecom for the construction of multi-service access network to expand the service coverage of Indonesia Telecom.

    These projects mainly deployed in Jakarta City and total capacity has more than 40 000 subscribers providing POTS, DDN, xDSL and Ethernet services.

    Figure 5 shows the application in Indonesia.

4.3 ZXA10-MSAN Application in Quanzhou Branch of China Telecom

Quanzhou Branch of China Telecom is the first telecom carrier to deploy the MSAN system in China and it started the construction in 2002.

    ZXA10-MSAN, as the first-grade brand multi-service access product, always plays the key role in China access network construction.

    Till the end of 2004, ZTE has already deployed about 150 000 lines

    ZXA10-MSAN system in Quanzhou Branch.
The service includes POTS, ISDN, DDN, ADSL/2/2+, Ethernet, IPTV, and more.

    Figure 6 shows the application in Quanzhou.

5 Conclusions
The IP technology and optical communication are the two most important footstones of the NGN network, and they are the key factors in access network field. The ZTE´s Fiber-to-the-World solution fully considering these two technologies when provides series of products including MSAN, MSAG and E/GPON system. These as the main components of ZTE F3G@NGN universal network solution, will play an increasingly important role in constructing the whole optical NGN network.

Manuscript received: 2005-10-09