The Active OTN and Passive WDM are two major technologies used by 5G fronthaul networks. However, the IP over OTN and Packet OTN are two key technologies popular in 5G backhaul network. The combination of optical and wireless networks is bound to create the future an extremely fast interconnected world.
Requirements for Transport Network in the 5G Era
ZTE's 5G-Oriented Optical Transport Network
Large-Capacity Optical-Electrical Hybrid Scheduling
ROADM/OXC +OTN switching provides ultra-large capacity and multi-granularity flexible scheduling, while reducing TCO, general power consumption and space occupation. It enables flatten networking, reduces E2E latency, improves the network throughput and makes the network much safer.
High-Rate Low-Cost Line Transmission
For 100G or beyond 100G mid-haul and long-haul transport, the coherent technology combined with silicon photonics effectively reduces the sizes, power consumption and cost of the optical modules. For short-range transport, modulation technologies like the PAM4 is used together with the DSP compensation algorithm to realize high-speed low-cost transport.
Low-Latency Transport and Forwarding
Optimize the internal mapping, multiplexing processing, forwarding mechanism, interfaces, and other aspects of OTN equipment so as to reduce the latency of one node to microseconds level.
Lightweight OTN for Fronthaul
To meet the requirements of 5G fronthaul, the new 5G-oriented OTN simplifies OTN frame architecture, eliminates unnecessary overhead, reduces multiplexing layers, changes error detection and correction mechanism and shortens cache time, therefore, it decreases the device cost, further reduces the latency and allows flexible bandwidth configuration.
IP+Optical & Packet OTN
By supporting IP+Optical synergy or Packet OTN-based device integration, the 5G-oriented network enables both flexible processing of small-granularity services and limitless capacity. Elastic transport pipes are provided to efficiently carry 5G services and support long-terms development of other services.
Flexible Bandwidth Adjustment
As ODUflex flexibly adjusts channel bandwidth at a step of 1.25G, it ensures highly efficient service transport and is applicable to multiple services. Also, by supporting G.HAO, the 5G-oriented OTN enables smooth time slot configuration and lossless bandwidth adjustment.
High-Precision Time Synchronization
The single-fiber bi-directional OSC channel is used to eliminate time delay asymmetry. The phase detection and zero-delay phase locked loop (PLL) technologies are adopted to carry out phase sync on the basis of frequency sync.Mark time stamps at lower layer to make them more accurate.
E2E Hierarchical Network Slicing
The transport plane can either be sliced on hard pipes such as λ, ODU and VC, or on packet soft pipes. Deploy bandwidth on demand (BoD) and optical virtual private networks (OVPN) on the basis of the SDN. Fast service provisioning and less operating expenses can be provided for large-scale networks, which satisfies the requirements of multiple services, multiple tenants and multiple vertical industries for network slicing.