An Optical Transponder Unit (OTU) board, such as Huawei 100G transponder LSC, 10G LSXB converts client-side services into optical signals carried over ITU-T–compliant WDM wavelengths after performing mapping, multiplexing, convergence, and other operations. OTU boards can be divided into Transponder and Muxponder by function, which are abbreviated as TP and MP respectively.
What is transponder?
A transponder is an active element that sends and receives the optical signal over a fiber. The key differentiators between various transponders are their data rate and maximum signal distance. Transponders convert the short-range SR/LR signal from a fiber optic network switch into a long-range xWDM signal. This enables the converted xWDM signal to be transmitted using an optical fiber over longer distances and multiple channels with transceivers and multiplexers.
As a result, a transponder is a key element when creating optical networks for demanding environments such as service provider networks and plays a critical role in signal transmission throughout the DWDM network.
N into N out: N * low-speed client-side services to N * optical signals carried over ITU-T–compliant WDM wavelengths.
What is muxponder?
Similar to a transponder, a muxponder is also an element for sending and receiving the optical signal from a fiber. However, a muxponder also has the capability to combine multiple services into a single wavelength by multiplexing several channels to a higher order signal. This enables more efficient use of the fiber than a transponder but it also means that muxponders can be used even when there are not any DWDM transceiver options. For instance, multiple 32G or 40G signals can be combined onto a single 100G or 200G output.
N into 1 out: N * low-speed client-side services to one high-speed optical signal carried over ITU-T–compliant WDM wavelengths.
Client services are SDH, SONET, OTN, SAN, Ethernet, video, and other services.
When to use transponders and muxponders?
An embedded network can be a simple and cost-effective solution for short to mid-range transportation of large amounts of data. However, a solution based on active transponders or muxponders is preferable when transceivers and switches are not fully compatible or when transceivers alone will not meet your needs.
For instance, you might need greater speed, distances or security than is otherwise possible with the switch and transceiver combinations already installed. Here are a few cases in point that exemplify when using a transponder-based solution can solve common challenges:
- When your network must be encrypted: Transponders and muxponders can help to protect sensitive data and meet regulatory requirements with encryption.
- When a network operator needs to hand off a gray (i.e. non-xWDM) signal to end users: Transponders and muxponders enable this while making it easier for ISPs to control and restrict the optical connection’s bandwidth.
- When data needs to be transported over long distances but the transceiver does not support long–distance xWDM: Although standard transceivers in form factors such as 100G QSFP28 are effective for transferring data within data centers, a transponder-based solution can bridge the gap and open up longer distances by supporting xWDM and adding FEC to the signal.
- When data needs to be transported at higher speeds than supported by transceivers on a DWDM network: Faster transceivers can be larger and switch vendors may prefer only to support smaller transceivers, but transponders are another way to support faster speeds regardless of the transceiver form factor.