Next Generation optical network to the path of integration and development

The Next Generation Network (NGN) is a hot topic in communication industry at present. As for the next generation optical network, taking SoftSwitch technology as the core, using high-capacity High density wavelength division system, large capacity optical switch with automatic configuration function, a new generation of optical routers, all kinds of low-end optical systems suitable for different occasions, (such as MSTP and RPR), All of these intelligent optical networking represent the direction of optical network development. For telecom operators, it is especially important to grasp the time and gradually evolve the network to the next generation.

I. Next generation optical network developed in competition and integration

China's communication career has entered a new period of development after experiencing the most glorious decade in China's communications history. Competition makes the era of high profit of telecommunication service is over, the reform and reorganization of telecom operators have changed the investment behavior of telecom operator greatly, and the petty plan and construction have been replaced by the fussy of project validation.

Unlike the voice-centred networks of the past, the next generation network will be a data-core fusion network. The China Network Communication (Holdings) Co., Ltd., which was born in the tide of telecom reform, was fortunate to be IP/WDM as the Technology Foundation and business platform of the network, and built a backbone network with 40G bandwidth, which lay a good foundation for business development.

From the perspective of business development, the business requirements of China Network Communications (Holdings) limited will come from the following areas in the next few years.

1. China's network Communications (Holdings) limited itself business growth. Over the past two years, the company's total revenue has been growing, bandwidth requirements increased by about one times every 4 months, CNC Two years has been several times to expand to meet the demand for data business growth, which is our biggest source of demand.

2. Xi Guohua, general manager of China Network Communications Group, put forward "competing to win the market, the integration of the creation of strength, integrity cast brand, service weaving future" group concept. With the expansion of the group business in the south, under the unified deployment of the group, our network will assume the task of further increase.

3. After 10 years of prosperity, the world's telecoms industry has followed online companies into the Dark Ages. In the case of China, the total revenue growth of the telecom industry slowed down in 2001, and for the first time individual operators in individual regions were even less than the GDP growth in the region. But we should also see that things are always in two, and that the effects of the market downturn and the intensification of competition are twofold, allowing operators to falter while extending existing network facilities while forcing operators to look for better business models. The result is a device manufacturer that has more powerful products that can support the newer business, which is the driving force behind technological advances. With the push of market demand, the new business will continue to emerge, and the result will be a significant increase in the volume of business.

It can be expected that in the next few years, the operator's network will be at least in the following directions.

(1) The growth rate of data traffic will not be stopped. In order to adapt to this kind of demand, in the network structure, the IP/DWDM still is the mainstream. Due to the construction of the main cable in the previous few years, there is no shortage of optical fiber in the economically developed coastal area, and the demand for the central and western regions is relatively small. As a result, operators will choose between hyper-dense WDM with a greater than 1.6T and the use of conventional 320G DWDM in the solution of the coastal route. In general, because of the complexity and cost of hyper-dense WDM dispersion compensation, operators prefer the latter rather than the former if they do not have sufficient financial benefits. In other words, operators will consider hyper-dense WDM only if the price is attractive enough to the operator.

(2) Pure SDH equipment has been pushed to the edge of the network over the past two years, and it is gradually replaced by a more versatile service delivery platform MSTP. MSTP provides operators with more flexible networking and more efficient business delivery and management patterns. At the core of the network, with the adoption of voice technology based on SoftSwitch, the demand of TDM will be gradually reduced, so the large particles can be used as the unit in the network composition and the service deployment, which provides the conditions for the application of OXC. However, at present, the OXC from the manufacturers are not ideal performance, most still adopt the OEO way, some mechanical oxc although the OEO process is omitted, but can not carry out the free conversion between different wavelengths so that its application has been limited. In the next few years due to technical defects OXC can only be limited use.

(3) The speed of the long-distance trunk network intellectualization will be accelerated, in the past, the way to adjust a circuit needs weeks or even months of the situation will be fundamentally changed. Driven by market competition, operators recognize that without an efficient operating service system (OSS) will not be able to provide users with quality and efficient services, and as OSS systems, the basic transport network will be given the highest priority.

(4) With the increasing competition among operators and the decrease of profit, operators will pay more attention to reducing the construction cost of the network. This forces equipment suppliers to seek ways to reduce manufacturing costs. Manufacturers will leave the core technology in their own hands and make many parts into modules, to the specialized companies to produce. The result is that production and even research and development will become socialized, which is a good thing for operators, because it means that the ever-changing proprietary interfaces will evolve more open and friendly, making it easier for operators to operate and manage their own systems.

(5) New technology from the birth to the use of the time will be shortened, such as Raman amplifiers, broadband light placed such products will be widely used. Optical devices that can be used to transform between wavelengths will be available. These new technologies and new products will make the optical network truly reconfigurable and manageable, making the network more flexible and reliable.

(6) Light processing technology will make a substantial breakthrough. The delay and jitter of signal are two difficult problems that are bothering communication engineers at present. At present, the so-called optical router's processing part is actually implemented on the electric layer, and the optical router will route the signal in the light layer, and its speed should be increased by one to two orders of magnitude compared with the traditional route processing. This new generation of real optical routers will be able to better adapt to some real-time business, such as radio demand, then can be no exaggeration to say that IP rule the world.

(7) The optical transmission system will be widely used in the next generation network, not only in backbone network but also in metropolitan area network and even access network. New systems with different functions will be adopted in the past. Among these new systems, the most representative SDH is the Multi service Transfer platform (MSTP) based on SDH and the resilient Packet Ring technology (RPR) based on packet switching. The two technologies address the problem of multiple-service delivery in two different directions respectively. At present, the development of MSTP has gone through two stages, the first generation of MSTP is to increase the IP and ATM transmission interface on the existing mature SDH system, and provide the transparent transmission function of point-to-point; the second generation of MSTP has enhanced the optimization of various data services on the basis of the previous generation, It can support the complete two-layer data function, support more transfer protocols, and further develop and create the functions of SDH, emphasize the management efficiency and transmission efficiency of the network, and reduce the equipment cost and running cost of the network. In contrast, RPR is largely dependent on the wide use of Ethernet. The establishment of IEEE 802.17 Resilient Packet Ring research group in early 2001 has made the RPR technology develop greatly. Independent RPR products are not yet mature, and when RPR and other technology integration, then glow strong vitality, such as WDM, SDH, and even the backbone of routers and other products to provide operators with more technical options.

In short, the next generation of network technology will be a new network, security, reliability, flexibility, support for a variety of businesses, with superior management performance will be its most important characteristics.

Second, the way to the next Generation Optical network evolution

Different operators of the original communication infrastructure is not the same, but the transition to the next generation network is the overall trend and direction, generally speaking, the transition strategy should follow the following principles.

1. Protection of established investment principles. Telecom operation Investment is huge, the next generation of optical network construction needs huge funds, operators are neither possible nor necessary to build a new network. Moreover, the new business is always continuous, step-by-step introduction, so operators will be in accordance with their actual needs of the gradual and orderly network to the next generation transition.

2. Principle of operational priority. Today, when bubbles are squeezed, operators will be most focused on the economic indicators that the network brings, and the new technologies that can bring direct benefits to the business will be adopted first, and operators tend to use less investment in exchange for larger returns.

3. Mature Product Priority principle. In the current description of the next generation of optical network of a wide range of products, a large number of not fully mature, and some are very immature. In the wake of the telecoms boom, most operators have become wary of using products that have proven to be mature and reliable, abandoning products that are technologically advanced but not fully mature, unless they bring gold to new businesses.

In accordance with the above principles, we can describe the Chinese network communications (holding) company Optical Network layer in the next few years the outline of the evolution.

(1) The capacity of the trunk optical network will be further expanded, the project will be completed by the end of this year, when our backbone capacity will be expanded from the current 40G to 320g+40g. At the technical level, the IP/DWDM approach will still be adopted.

(2) Set operation management and business management as one of the boss system will be placed in the priority position, the company hopes to rely on this to establish a strong business and network management system.

(3) on the basis of the previous two years ' operation, we will compare RPR (resilient packet ring) and multi-service transfer platform (MSTP), which will continue to be adopted on our network, which is the core of our metropolitan area network.

(4) in the backbone of our network, we will see the status of technology development, the appropriate introduction of OXC to improve the flexibility and scheduling of the network, provided that these oxc must have good manageability, configurable, reconfigurable performance.

(5) Study the possibility of the use of various passive optical networks in the access layer, our door is open, we are willing to work with all manufacturers, because this is a winning strategy.

Next Generation network, especially next generation optical network is a broad concept, its evolution process is long, perhaps a few years, perhaps more than 10 years, in the process of evolution will have a new content to add in. In any case, this is a direction that is not only driven by technology but more importantly by the market.