PARTNER FEATURE: In recent years, 5G has become the focus in the industry. 5G standards are being completed and breakthroughs are being made in 5G technology R&D. Large-scale commercial deployment of 5G is coming. In the near future, 5G will penetrate into different fields, closely connecting to people’s lives and building a comprehensive information ecosystem for users.

In the 3G/4G era, operators have tried to use C-RAN architecture in radio access network (RAN) to reduce network construction costs and power consumption, and implement fast site construction and simplified operation, administration and maintenance (OAM). In 5G networks, C-RAN deployment is an inevitable trend. It can provide more flexible wireless resource management, decouple software from hardware, and meet the requirements of mobile edge computing.

Compared with 4G networks, 5G has wider spectra, higher spectral efficiency and denser base stations. In practice, the access rate per unit area of 5G is increased by dozens of times than that of 4G. The corresponding transport network bandwidth also needs to increase by dozens of times to meet the transport requirements of enhanced mobile broadband (eMBB) services such as 4K/8K ultra-high definition video and VR/AR. In the 5G era, ultra reliable & low latency communication (uRLLC) services such as tactile Internet, telemedicine, and autonomous driving services with strict requirements for latency and reliability will be gradually introduced and popularized. Transport devices and networking modes must be optimized to reduce latency and improve reliability. Generally speaking, the key requirements of 5G lie in ultra-large bandwidth, ultra-low latency and high reliability.

5G network construction needs powerful support from the transport network to meet the key index requirements of 5G, boost sustainable development and evolution of 5G networks. In the C-RAN architecture of 5G, one CU/DU site will be remotely connected to multiple AAU sites. How to solve Fronthaul service transport between the CU/DU site and the AAU sites, has become one of the major problems in 5G network construction. ZTE recommends using the OTN-based remote unified transmission solution (Figure 1) that can save substantial fiber resource and provide ultra-wide transport pipes, ultra-low device latency and rich OAM measures.

ZTE’s OTN-based remote unified transmission solution is based on OTN product ZXMP M721. It is implemented by the combination of ZXMP M721 OD62 and ZXMP M721 CX series devices. The OD62, deployed at the AAU side, is a new outdoor integrated cassette OTN device that is adaptable to various harsh external environments. The CX series subracks, deployed at the CU/DU side, are compact OTN devices that are generally placed indoors. The major advantages of this solution together with its OTN devices are as follows:

  • Unified transport platform cuts network construction costs

Dense deployment of 5G base stations makes it more likely for them to share the sites of 2G/3G/4G base stations. Besides, in CBD or commercial office building scenarios where mobile networks coexists with fixed networks and enterprise private line networks, how to use limited fiber resource to implement unified transport of different services is especially important. The OD62 device supports hybrid access of CPRI option 2~7, eCPRI, STM-N and Ethernet services, builds the unified transport platform of 5G/4G/3G/2G Fronthaul networks, remote fixed networks and private line networks. This solution dramatically cuts the network construction costs of operators, and can implement fast large-scale deployment of networks.

  • Ultra-large transport capacity guarantees good user experience

The OD62 device is the first outdoor OTN device with 200G bandwidth for remote unified transport. It provides rigid transport pipes to effectively isolate services accessed and guarantee lossless service transport. Sufficient bandwidth and reliable transport ensure that there is no lagging or blurred screen when users watch 4K/8K ultra-high definition video or use VR/AR in 5G networks. This solution provides high-quality experience for users.

  • Ultra-low device latency satisfies user demands in real time

By introducing the FlexO technology, the ZXMP M721 device can implement ultra-low latency end-to-end service transport within 1μs, providing guarantee for application and popularization of 5G in the uRLLC scenario. In telemedicine and remote rescue scenarios, it can rapidly respond to the users’ requests and provide real-time interaction between the two parties by video to ensure timely treatment and help for users.

  • Saves fiber resource and reduces municipal workload

The OD62 device can support the access of 15 services from the client side and single-fiber bidirectional transport at the line side. Compared with direct fiber connection, the use of the OD62 device can maximally save 97% of fiber resource. The operators can use the existing fiber cables to meet the 5G network construction requirement without laying more fibers. Besides, the OD62 supports flexible installation modes, including pole-mounted and wall-mounted installation, without occupying any space in the equipment room. Generally speaking, this solution can save public resource and reduce municipal workload. It does not affect people’s daily lives, supporting environment protection and sustainable development.

  • Convenient deployment and reliable OAM

The OD62 device supports services automatic identification, so that services can be activated after power-on without any configuration. The network deployment is human-friendly. The OD62 device employs innovative remote wireless control technology to implement OAM under the tower, reducing the difficulty and costs of OAM and guaranteeing the security of OAM persons. Besides, as an active solution, this solution has rich OAM functions, providing reliable OAM for remote devices.

ZTE’s OTN-based remote unified transmission solution that fits the C-RAN networking architecture has such advantages as large bandwidth, low latency, high reliability and convenient OAM. The solution can effectively reduce the network construction and operation costs for operators and help operators to deploy remote networks at scale to seize the market rapidly. The solution will bring much convenience to more people and lead an new era of Internet of Everything.