Typical applications for the 100 Gbit/s transmission solution are shown in Figure 1.

The unique technical advantages of Huawei's 100 Gbit/s coherent transmission solution focus on four aspects: ultra-long-haul transmission, simplified network, efficient bandwidth utilization, and low latency:

• Ultra-long-distance transmission:

  Multiple technologies, such as ePDM+QPSK/ePDM+BPSK modulation, coherent reception technology, FEC, and hybrid optical amplification, are used to realize ultra-long-distance transmission distances without electric relay.

  Fig. 2 Coherent system ultra-long distance transmission
  

  
• Efficient bandwidth utilization:

  Supporting multiple services and rate access, multiple services can be encapsulated and accessed into ODUk (k=0, 1, 2, 2e, 3, 4, flex) through OTN technology, and scheduling is carried out through unified OTN crossover to ensure efficient utilization of bandwidth, reduce the cost of transmission per bit, and maximize the realization of bandwidth sharing.

  Fig. 3 Efficient bandwidth utilization in coherent system
  

  
• Simplified network:

  Simplify network architecture and reduce network design and O&M costs through the benefits of DCM-free, large PMD tolerance and simplified ROADM architecture.

  Figure 4 Coherent Systems Simplified Network
  

  
• Low-latency:

  A low-latency transport network can be formed, which is especially suitable for carriers to provide dedicated transport pipes for various commercial services such as finance, data centers, cloud computing, and other services that have a strong demand for low network latency.

  • Huawei's advanced FEC technology provides optimal net coding gain while featuring extremely low latency.
  • The DSP chip of the coherent single board has superior electrical dispersion compensation and electrical PMD compensation capabilities, eliminating the need to configure DCM modules in new 100G networks, which not only reduces network construction costs, but also eliminates redundant latency in the DCM modules.
  Figure 5 Coherent system low latency