Contentionless, Directionless, and Colorless (CDC)

-

 

Contentionless, Directionless, and Colorless (CDC) are terms used in the context of wavelength-division multiplexing (WDM) optical networks to describe certain capabilities of optical add-drop multiplexers (OADMs) and reconfigurable optical add-drop multiplexers (ROADMs). These capabilities aim to enhance the flexibility and efficiency of optical networks. Let's break down each term:

  1. Contentionless: In a WDM network, multiple optical signals (wavelength channels) can share the same physical path, and at times, contention can occur when two or more signals request access to the same wavelength channel. A contentionless OADM or ROADM is designed to handle such situations without causing signal interference or data loss. It can allow different signals to be added or dropped independently, even if they share the same wavelength, by using wavelength-selective elements like filters or wavelength blockers.

  2. Directionless: A directionless OADM or ROADM has the capability to add or drop optical signals on any input/output port without being limited to specific directions or paths. In traditional optical networks, the architecture might require specific input/output ports for adding or dropping signals in certain directions. A directionless CDC device removes this limitation, allowing flexibility in adding and dropping signals regardless of the input/output port.

  3. Colorless: In the context of optical networks, "color" refers to the specific wavelength of light used to carry data. A colorless OADM or ROADM does not rely on predetermined or fixed wavelengths for signal addition or dropping. Instead, it can handle multiple wavelengths without being wavelength-specific. This means that it can add or drop signals at various wavelengths without being constrained to particular wavelengths.

The combination of these capabilities—Contentionless, Directionless, and Colorless (CDC)—results in more efficient and flexible optical network architectures. CDC capabilities enable network operators to dynamically allocate and manage optical channels, optimizing network resources and allowing for greater adaptability to changing traffic demands and network configurations. These features are especially valuable in modern optical communication systems where flexibility, scalability, and efficient resource utilization are key considerations.

Comments

Post a Comment

Popular posts from this blog

What is CDR in Optical Modules

-
  What is CDR (Clock and Data Recovery) in Optical modules?   The full name of CDR is clock and data recovery, which can be simply understood as after the optical signal is converted into an electrical signal, the receiver performs electrical domain shaping and clock recovery.    CDR has two main functions 1. The first is to provide clock signal for each circuit of receiver;  2. The second is to judge the received signal, which is convenient for data signal recovery and subsequent processing.   Because when the optical signal is transmitted to a certain distance, it is usually long-distance transmission, and its waveform will appear a certain degree of distortion. The signals received by the receiver are pulse signals of different lengths. At this time, at the receiver, we can not get the data we need. Therefore, signal regeneration is needed at this time. Signal regeneration functions include re amplification, re shaping and re timing. Re-timing refers to CDR cl
Read more

What is Super C-band

-
Image
  Super C band uses the ultra-wide C band (C120) in addition to the traditional C band (C80) and the extended C band (C96). It increases the available wavelength range. Super C band can transmit 120 wavelengths at a 50 GHz channel spacing and transmit 80 wavelengths at a 75 GHz channel spacing, greatly expanding the effective working spectrum compared with the traditional C band and extended C band. Therefore, it is called Super C band. Benefits of Super C Band - Improving the system transmission capacity When the transmission rate is the same and the channel spacing is 50 GHz, the Super C band supports a maximum of 120 wavelengths, while the traditional C band supports a maximum of 80 wavelengths. The Super C band increases the transmission capacity by 50%. Refere for more details: Huawei-Super C Band
Read more

What is OpenZR+ for tranponder/muxponder

-
Image
Introduction OpenZR+ defines specifications for 1 00 - 400G single - wavelength optical ports for transceiver/transponder, muxceiver/ m uxponder ( TRXR/ TRPN , M U XR/M UXP ) node functions and for switch/router optical ports .   Open ZR+ Architecture   The architecture, shown in Figure 1 - 1 includes client sub - layers for up to four 100GBASE - R clients , up to two 200GBASE - R clients and a single 400GBASE - R client . Client data and alignment markers are extracted and re - timed to the line side clock domain using the general mapping protocol ( GMP ) . Retimed data plus GMP timing information is then mapped into one of the OpenZR+ frame formats . Those frames are multiplexed and OFEC encode d and become the payload of a DSP frame with DP - 16QAM, DP - 8QAM, or DP QPSK symbols .
Read more