by http://www.fiber-mart.comCurrently the data, voice, and video networks are becoming more complex and demanding more bandwidth and faster transfer rates far greater distances. To achieve these demands network executives are relying more about fiber optics. However, the actuality that many providers, enterprise corporations, and government entities are facing is the point that when their existing fiber infrastructure is overwhelmed, placing more fiber is not in fact an inexpensive or viable option. Hence, what now one should do!
Many entities are opting Wave Division Multiplexing (WDM) technology in order to increase the capacity of their available infrastructure. WDM carry multiple optical signals of different wavelength onto a single fiber by multiplexing. By using WDM technology network executives can achieve a multiplication effect inside their existing fiber capacity. WDM is a protocol and bit rate independent. WDM based networks can transmit data in IP, SONET/SDH, ATM, MPLS, Ethernet and support bit rates from 100 Mbps to 40 Gbps. Consequently, WDM based networks can hold several varieties of traffic at different data rates over an optical channel.
This makes a less costly method to rapid response to customers’ bandwidth needs and protocol changes. To regulate bandwidth and increase the capacity of existing fiber optic infrastructure, WDW based networks, by simultaneously multiplexing and transmitting various signals at different wavelengths within the same fiber. As division and distributing business services tend to be more extensive, WDM optical technologies are becoming an appreciated tool for cable operators. Using just two different wavelength, WDM technology can increase the service capacity by twice with in the same amount of fibers. For quite some time, there have also been some limited methods using more complex WDM systems that may carry four or still more optical signals on same fiber. Lately, cable equipment makers have released revolutions using WDM that transmit multiple broadcast optical signals on the single fiber, making node division more cost effective and operationally friendly. WDM significantly increase the capacity of system.
You will find variations which can be popular: Coarse WDM (CWDM) and Dense WDM (DWDM). Each signal is at a different wavelength and each variation had different capabilities, cost, and operative friendliness, used in different WDM Multiplexer (or de-multiplexer) devices. Multiplexer merges several data signals into one signal for transporting on the single fiber while de-multiplexer separate the signals equally. CWDM technologies have only been produced for HFC (Hybrid fiber-coaxial) networks within the return-path up to recently. About return-path, almost eight transmitters at different CWDM wavelength can be multiplexed on to a single fiber using a CWDM Mux. This could be beneficial when return-path has lot more bandwidth contention related to the forward-path, so 24×7 node segmentation may be sufficient.
DWDM technologies delivers much flexibility for node breakdown, yes it is more expensive and more operationally challenging ac compared to CWDM. The method to fragment the nodes using DWDM within the forward-path is known as broadcast/narrowcast DWDM overlay. It utilize two fibers within the downstream: one fiber having an optical signal with all the broadcast content, and other fiber with multiple optical signals on DWDM wavelengths, each containing unique narrowcast content to obtain a segment.
On the node, the narrowcast DWDM wavelengths are separated onto their unique fibers. The narrowcast content will then be overlaid with the broadcast content at the node in a choice of the RF domain or perhaps the optical domain.