Now the MAN business continues to enrich the MAN capacity requirements are also increasing. However, in the construction of MAN, due to the limited transmission resources of operators that have laid optical fiber, it is necessary to find new solutions to increase the bandwidth capacity of MAN.
WDM technology — a good helper to solve the problem
In recent years, with the substantial improvement of backbone network capacity and access network capacity, the capacity bottleneck of the network has been gradually transferred to the MAN, so the construction of broadband MAN is gradually becoming the hot spot of telecom and network construction.
Due to its relatively small geographical area, relatively concentrated population and other factors, people are faced with short transmission distance, wide band, flexible access, diverse and complex business problems.
Short transmission distance
Compared with backbone network, the service transmission distance in MAN is shorter and more sensitive to cost.
Flexible access mode
With the increase of business innovation, the speed of business generation is faster and faster, the user needs are more and more difficult to grasp, the MAN needs to have enough flexibility, scalability and rapid response ability to adapt to changing needs.
With the increase of users, the growth of service bandwidth, as well as the development of interactive network television (IPTV), video monitoring and other types of Internet broadband applications, to the MAN caused huge bandwidth pressure and business management pressure, the MAN expansion and upgrade is imminent.
Business is diverse and complex
Man should not only carry the traditional time division multiplexing (TDM) business, Internet business, but also consider the rising IPTV, next generation network (NGN), 5G (fifth-generation mobile communication), peer-to-peer network (P2P), enterprise broadband applications and other emerging business.
Therefore, considering the transmission distance, capacity and service type of MAN, it is an inevitable trend to gradually introduce WDM into LAN to solve the bandwidth bottleneck of MAN.
How does CWDM technology apply in MAN?
At present, CWDM technology is relatively mature and the product is relatively simple. It can be applied in the access layer and convergence layer of MAN, but cannot be used in the core layer. Because the 2.5Gbit/s carrying service rate and 8-wave capacity of the CWDM system in the core layer of the MAN cannot fully meet the network requirements of the core layer of the MAN, and for the access layer and convergence layer of the MAN, the number of required wavelengths is generally no more than 8, most of the current CWDM systems can provide 8 wavelengths.
At the same time, in the local network, there are often some situations where the transmission distance is long and the fiber resources are limited. The low-cost characteristics of CWDM system can be maximized when the transmission distance is between 0 and 50km, so the CWDM system can truly show its competitive advantage under the urban edge network and the local network.
