CWDM (Coarse Wavelength Division Multiplexing) systems, coarse wavelength division multiplexing system, or coarse wavelength division multiplexing technology, more and more recognized by people in the metropolitan area network application as an economical and practical short-distance WDM transmission systemand already practical use. The development of information technology, especially in INTERNET IP data represented the rapid growth of the business, resulting in growing demand for bandwidth transmission line. DWDM technology as one of the most effective line bandwidth expansion, in the long-distance backbone network get a wide range of applications, has basically meet the current demand. Network transmission bandwidth bottleneck gradually transferred to the MAN, MAN into a hotspot of network construction. Coarse Wavelength Division Multiplexing (CWDM) system with its unique advantages in the the MAN construction of more and more attention.
CWDM system can effectively save the fiber network resources and cost, it is to solve the shortage of optical fiber and transparent multilservice transmission two issues, mainly used in metro aggregation and access layer, and in a short time within the construction of the network and conduct business. CWDM has many advantages of low cost, low power consumption, small volume, currently has a large number of applications in the metropolitan area network transmission. FiberStore Co., Ltd combined with market demand, develop applied to G.652, G.653, G.655 fiber EXP λ series CWDM equipment to major operators and system integrators to provide a low price, high-performance transport solutions, is the ideal choice for the growing metropolitan area network.
CWDM system provides flexible networking modes, can be composed of point-to-point, star, chain, ring topology, attractive competitive regional carriers. CWDM in the industry has been on the market more and more applications.
>> Certain institutions of higher learning of the new and the old campus expansion applications (peer-to-peer networking mode)
In recent years, with college enrollment, many schools campus classroom building, student dormitory can not meet the requirements of the growing number of students. In order to comply with the trend of the development of higher education, to expand the size of school, and to enhance the school’s overall strength, all colleges and universites to establish a new campus. The main campus, however, generally are located in the downtown area of the economy, is unable to estimate the cost of the expansion of the main campus, and by surrounding a number of factors, not the reality. In this way, the vast majority of colleges and universities are the new campus built in the suburb of tens of kilometers away from the main campus. The new campus built, the allocation of teaching resources placed in front of the problem.
The new campus, school teaching and student life Internet requires a lot of bandwidth resources. If the formation of a new network in the new campus, the cost is undoubtedly a great new and old campuses also need a lot of business contacts, and teaching needs. If the formation of a new network in the new campus, the cost is undoubtedly great. The old campus has a strong network of resources, how to use?
Fiber between the old and new campuses are generally schools hire operators, however, the annual cost of the rent bare fiber is particularly high, how to hire a little fiber to meet the requirements of the large volume of business? CWDM technology is undoubtedly the best solution.
The following figure is a CWDM system is applied to the case of a university in the center of the old campus network a provincial network nodes, the adequacy of resources; new and old campuses distance 40km, rent a pair of fibers of the local operators. Expansion of six two-way data services to customer requirements in a single fiber pair per channel rate 2.5G.
A brief description of the program:
:: Typical point-to-point transmission scheme.
:: CWDM wavelength division multiplexing equipment full business can do 1:8 expansion, that is, using a core fiber can carry 4-way wave two-way business, two-core fiber can carry 8-channel 16-wave two-way business.
:: The highest rate of each channel can reach 2.5G, down compatible to 100M.
:: CWDM equipment the the relay transmission farthest up to 100km.
:: This scheme does not use the conventional single-fiber one-way transmission mode, the 6-way operations separate groups Bidirectional transmission, if a fiber failure, does not affect the
business of another fiber.
>> A video transmission network expansion application (star, chain the shape networking modes)
1.B, C, D, E, F, G each node requires two-way video and two-way video signals to the central node A aggregation.
2.Per signal rate up to 2.5G.
3.Each node is provided between the double-core fiber. As shown below:
1. A point to a central node in the engine room, a star topology with BDFG each node in the engine room.
2. AC, AE node does not have a direct fiber link, respectively, after the two-point routing of the B, D to A, in order to reduce the number of transmission cascade, ABC, ADE constitute a chain topology using OADM technology.
The Program Figure as follow:
1. Represents the trunk single fiber optic, expressed one pair of fiber optic business.
2. This program in the F and G are two points using only one fiber for leaving a core as a backup or expansion.
3. This program two points B, C and D, E two points, respectively, with a core optical fiber transmission, so that only two points B, D OADM technology, which can effectively reduce the OADM
cascading layers of trunk lightsignal loss; addition, for customers leaving a core fiber as a backup or expansion.
4. All use a single core bi-directional technology, to isolate business, if a fiber failure will not affect to a fiber-optic business.
5. This program is provided in the B, C, D, E, F, G points two channels bidirectional optical business, all brought together to the point A.