Huawei Technologies

Transcription

1

2 EXPERT S FORUM Connecting the world at the speed of light From lightening-fast downloads to seamless video conferencing to crystal clear HD television, fiber optics harness the power and speed of light to bring users incredible possibilities and total convenience. Not surprisingly, FTTx has emerged as the optimum choice for fixed operators who are desperate to deliver customers faster broadband-based services and better experience. Leading operators such as Telecom Italia, have already embraced the FTTx advancements and started network deployment. Their experience and opinions will certainly provide valuable reference for their peers worldwide. 5

3 6

4 EXPERT S FORUM EXPERT S FORUM Antonino (Toni) Ciccardi is responsible in Telecom Italia Lab of the Architecture for FTTx Access Network Project. He currently works in the Fixed Access and Transport Department s Innovation Area, and his specialism is NGN deployment programs. Telecom Italia s NGN2 evolution By Antonino (Toni) Ciccardi Telecom Italia has been studying architectures, functionalities, techniques, equipment and systems to define the best evolutionary path of the access network to fine tune the huge investment this segment requires. Hereafter we can share some ideas on the Telecom Italia s strategy for access network transformation via the NGN2 implementation. Why to move to NGN2? As we know, customer requirements on bandwidth have increased significantly. Customers are now using services such as web surfing, video communication, Standard and High Definition IPTV, in addition to more symmetric applications such as peer to peer, remote disk backup, personal streaming production, and so on. ADSL/ADSL2+ technology, however, is no more sufficient to meet these new service requirements. Moreover, ageing of network equipment, jointly with central office rationalization for OPEX saving are pushing to the introduction of a new access network: the NGN2. Taking into account that today the operator networks are still dominated by copper cables, a key element for NGN2 development is represented by the xdsl technology, so we need to know some Considering that Telecom Italia boasts relatively more densely populated dwellings, FTTB emerges as its first choice for the FTTx deployment. basic on it. If the distance between central offices and customer premise exceeds 1km, you can still continue to use the ADSL instead of VDSL, since ADSL is cheaper, more stable and optimized technology and delivers a comparable performance. If the distance is less than 1km, VDSL performs significantly better than ADSL; compared with ADSL s, the VDSL can be ten times more reaching Mbps with short loops. Which architecture? FTTx architecture includes FTTCab, FTTB and FTTH, which can be used to serve customers located at long distances from central offices. The deployment of FTTx architecture has been evaluated taking into account the dwelling type and a building s characteristics specific in the Italian territory. For instance, Italy is not a country with many new buildings, and compared with other EU countries Italy has considerably less semi-detached and detached family houses; our cities are characterized by being populated by highdensity dwellings. Approximately 25% of our buildings have more than 10 dwellings and 35% have less than 10. Considering these factors, FTTB emerged as our choice for the first deployment. How to start? We have already started an NGN2 field trial in Milan. For each building, we are installing a new cabinet in the basement of the building (FTTB) or nearby (FTTCurb). The GPON guaranties the backhauling between the new cabinets and the closest central office, while VDSL2 is used between the new cabinets and the customers houses placed in the building. A small capacity (12/24/48 lines) ONU-B or ONU-Curb equipment with the following characteristics is installed: 1 inlet fiber, capacity of up to 48 VDSL2 7

5 customer lines over existing copper pairs, outdoor or indoor cabinet installation, 200m maximum distance of the existing copper customer line between ONU and customer. The ONU-B is locally powered and it is assumed that, at least in the first phase, POTS and ULL services from the C.O. are supported, and the transition from POTS+xDSL towards VDSL2 services will be managed through the adoption of a proper equipment called ST&T (Switching, Termination & Testing). The main reason for adoption of the ST&T is the automatic provision of the VDSL2 service. In fact, since the Telecom Italia network has got around 10,000 central offices, 100,000 cabinets that serve more than 1 million buildings it could become very expensive to adopt an electronic distributed architecture without a smart remote provision solution. With regard to the service provisioning at building side, ST&T can have several configurations, like for example ONU bypass to provide only POTS or ULL from central offices, VDSL2 or POTS+VDSL2 if the customer wishes to have Ultra Broadband service. A f u r t h e r p o i n t o f a t t e n t i o n i s represented by the power consumption issue on the access network evolution. Telecom Italia is committed to reducing power usage. We have managed to reduce power consumption when deploying xdsl products by using energy saving systems. New challenges on energy saving have arisen, and we must take further action on TLC equipment pushing manufacturer to implement specific technique (e.g. switch-off of unused electronic) for power saving. The adoption of remote VDSL2 equipment will not help to limit the power consumption per port, but we plan to further reduce our energy consumption during NGN2 project implementation. To achieve this, we have picked system and technologies specifically designed to minimize power consumption. Moreover, we are dedicated to implementing energy saving techniques and to optimizing our standardization process regarding power saving methods. So, since 2006, Telecom Italia has published an annual sustainability report containing an eco-efficiency indicator, and actively cooperated with equipment suppliers to enhance power efficiency so as to employ equipment that features low power consumption. Economic and coverage concerns Concerning the next deployment plan we are continuously working introducing innovation that may impact on economics and coverage plans of our NGN2 project, making more convenient one of the studied architectures: FTTC, FTTB, and FTTH that figure out different cost structures based on factors such as electronics, infrastructure and CPE. Today Telecom Italia is carrying on many effort to decrease the cost of FTTH solutions through experiencing new materials and technologies for vertical cabling in the building, pushing the standardization bodies (both in the national and international contexts) to introduce new recommendations, specifications able to optimize the installation and deployment of the fiber on field. The hope is to have a relevant CAPEX drop to make FTTH massively feasible so to arrive more easily and in a cost effective way to the target architecture based on FTTH. Editor: Gao Xianrui sally@huawei.com 8

6 EXPERT S FORUM EXPERT S FORUM Frank J. Effenberger: Director of Future Wei Technologies, Plano, Texas, is leading a sizable (20+ people) research team focused on advanced FTTx network concepts. Frank possesses extensive experience and expertise in international broadband access standardization, and is currently developing next generation access system architecture. The vision of green ultra broadband marks the road we should travel in terms of telecom access networks. The future is set to become IP-based, and will be driven by the goal of seamless service dilivery and experience. The ideal situation is delivering to customers whatever services they want, wherever they are, and whenever they want it. For example, customers would be free to watch TV at home or when traveling. The key challenge lies with causing different networks and components to talk effectively to each other. IP certainly forms the common language, but we find that translation into this language often brings with it costly overheads. Green ultra-broadband strategy From t h e p e r s p e c t i ve o f a c c e s s networks, we require a true broadband network to ensure that the system works properly. A broadband network is required to provide services such as IPTV. To fully utilize legacy networks, we need full service networks, full service providers, and full service equipment providers. The green ultra broadband strategy necessitates a carrier-class ALL IP network. The previous IP phase mainly focused on data communications, which we need to elevate into a carrier-class ALL IP network with different levels of manageability and sustainability. Only by achieving this can we hope to reduce the total cost of ownership (TCO), including CAPEX and OPEX. In terms of green eco-friendliness, we have to consider life cycle costs such as direct and indirect power consumption. For example, the organization of site-maintenance crews uses power in terms of vehicle usage and so on. Technical choices are sometimes shortsighted as they seek to initially curtail capital expenses, but then in fact consume greater amounts of power over the long-term. Government mandates are very likely to soon force us to look at power consumption issue at the very beginning. Network evolution reveals an ongoing trend towards flatter networks with centralized functions. Legacy networks are characterized by high numbers of small central offices that can, for instance, extend to one per town. Technologies such as Ethernet or fiber can return the functions of these offices to metro networks and thus subsume their point of presence (POP) role. Over the medium term, technology can reduce the number of network nodes. The services originally transmitted via copper wire can instead be carried on fiber, which can in turn reduce power consumption. In addition, we can improve electronic device efficiency. These measures can reduce the number of c e n t r a l o f f i c e s a n d P O P requirements. Furthermore, PON technology s future Fiber Access' Future By Frank J. Effenberger 9

7 development may allow the closure of even larger central offices to further reduce energy consumption. Among all available PON forms, GPON is outstanding for its ability to provide full service access networks. Currently, many operators have a range of services running on their networks. With the power of a GPON network, we can not only provide services to residential customers, but also expand a network to cover all the services as needed to provide. Network convergence can deliver one access network that supports all the required services, and this can lead to enormous savings in equipment, service provisioning systems, and training. Moreover, initial increases in building infrastructure construction investment will be rewarded in the long term with a notable reduction in TCO. Progress of the FTTx standards A successful and popularized GPON requires a mature standard system. Many experts from around the world have been actively attending the multiple standardization groups. The leading GPON organization, and also the technology s source, is the Full Service Access Network (FSAN) group. Recent research is focusing on fiber supervision. With additional equipment, the capability of the PON system can be enhanced by about 60km, or even more. In teroperability testing is ver y important. FSAN is taking the lead to bring different vendors together and confirm that standards compliance. FSAN comprises a number of senior technical officers who are responsible for the majority of issues, and editors who are responsible for documents. Much work deriving from FSAN is translated into ITU questions regarding, for example, optical access. So far, we have compiled four sets of documents that describe GPON, and have expended much time and effort to further develop and maintain these documents. When viewed from a different angle, the DSL Forum s (now the Broadband Forum) focus on GPON has enlarged considerably, and the group has provided standards coverage from a range of perspectives. The ITU and FSAN are viewing lower-layer protocols, while the DSL Forum is focusing upon higher layer protocols, including data service definition. We are working to provide an essential link between the different forums given that different groups are working on the same technology, and that their intercooperation is essential. North America has system requirements that differ from those in Europe and the rest of the world, and the gap between standards variance needs to be addressed. In technical terms, we are looking at the development of the new GPON standard features into our world leading product line. We endeavor to optimize resources to ensure that the standards formulated can deliver the highest system performance at a reasonable cost. A working group is currently engaged in research concerning the type of extension that yields the best cost performance ratio. We now have products based on some of these standards, which demonstrates the very short cycle that spans concept introduction, standardization, and production. We try to accelerate this process to the greatest possible extent. Interoperability forms a sensitive issue, and considerable effort is required to coordinate and resolve different disputes and standards. The interoperability test group is currently writing an implementation guide to fully clarify procedures. The standards cannot be completed without the next generation access PON and to this end a working group is assessing the next phase for GPON. The 10G PON seems to provide an effective green solution, but questions still remain whether 10G is cost-effective when this service is provided to individual customers. We are jointly approaching the 10G EPON project, and have submitted numerous baseline contributions. We have some working 10G system prototypes in our laboratory, including those designed for individual customers. There is also a group working on integrating different PON standard families as some areas now use EPON, while others prefer GPON. At the 10G level, we are aiming for all of these systems to be integrated into a single system. The white paper issued by FSAN will be submitted as the foundation for standards construction within the ITU, and we have put much effort into progressing EPON. Regarding standards convergence, we see that many current 1G or 2G systems simply do not talk to each other. In fact IEEE has also experienced problems in terms of narrow-band transport. Some are mutually standardized by operators, while others are private standards used by only a single company. At the 10G level, we envisage a single system that can be shared by different operators. In this case, we can construct a system based on an identical architecture. ITU and IEEE should cooperate to strive for this goal. Huawei fiber access footprint PON technology has developed from TDM-based PON, APON, and later, in 2003, into BPON. Many PON systems have been deployed based on low rate DSL systems. FTTB and other newly deployed products are important for GPON s commercial success. The development of IP DSLAM and chipsets also contributes to PON s development. The integration of residential and business services is significant given that different customers require different services. To solve this problem, Huawei utilizes a variety of ONT technologies, including traffic management features. Huawei has developed the interfaces needed to support mobile broadband and legacy networks, and is able to provide network design and turnkey services. Proactive involvement in standards development has seen Huawei deliver platforms with enhanced speeds from Megabit to Terabit using its own chipsets. To further develop the green platform, Huawei employs its own unique technologies such as thermal management, which considerably reduces maintenance and power needs by negating the need for a fan. To date, Huawei has signed contracts for PON systems with operators worldwide, including Europe s top operators. Editor: Joy zhouhj@huawei.com 10