Unlocking the Full Potential of Fixed Networks

Fixed and mobile networks have always been promoting and affecting each other. The development of one network spurs changes to the other, further accelerating technological innovation and network transformation. As 5G matures, fixed networks have also entered the 5G broadband (5GBB) stage. This kick-starts the era of dual-gigabit speeds based on fixed broadband (FBB) and mobile broadband (MBB).

FBB to Meet 5G Challenges

Compared with 4G, 5G enables over 100x faster speeds, seamless connection and handover of a massive number of terminals, and a significantly lower latency (1ms). This imposes high requirements on the capability of a network, which can also be extended to FBB networks. FBB networks need to utilize their inherent advantages to provide higher bandwidth, better QoS and greater reliability. The rise of 5G forces FBB networks to change and innovate (e.g., providing ultra-high bandwidth and connecting low-latency services).

Upgrading to 10G-PON

With the single-service operation model losing steam, many legacy operators are making strategic transformations. Some multi-service operators replace their cable networks with FTTH infrastructure. As latecomers to the game, alternative operators entice customers through innovations.

10G-PON is a powerful tool for operators to attract users. China accounts for more than 70% of the global FTTH market. When large-scale 10G-PON deployment starts in China, the 10G-PON industry chain will be fast improved to offers lower costs, which will in turn drive the 10G-PON deployment worldwide and stimulate the broadband development.

It is expected that the next five years will be the golden period for 10G-PON deployment. Due to the need for constant network upgrades in the future, equipment should be made flexible, for example, one card supports two generations of technologies, or one platform evolution within three technology generations. This reuses the existing network resources and lowers the cost of upgrades such as from GPON to 10G-PON.

Introducing IT Capabilities into CT Devices

As video becomes a basic broadband service, user attention shifts from bandwidth to experience. To create an efficient and smooth user experience, higher bandwidth, less jitter and smaller packet loss are required, and operators need to find differentiated means while making the most of their legacy network resources. Building IT functions into CT devices is an industry trend, which allows a network to have higher utilization ratio, more powerful functions, and easier scalability, and also allows operators to increase user stickiness and get a competitive edge over OTT players.

ZTE's Innovations in FBB

To achieve the above purposes, FBB networks need to be innovated to adapt to the evolving market situation and the changing application scenarios. ZTE has made a lot of exploration in FBB to improve service/network competitiveness.

10G-PON

Based on a deep understanding of the FTTx field, ZTE made 10G-PON a development priority for the next 10 years as early as 2012. It has since made many innovations in solutions and products centered on 10G PON and implemented many network deployments and evolutions (Fig. 1).

In 2016, ZTE launched the innovative Combo PON solution to enable large-scale, cost effective deployment of 10G-PON networks. One Combo PON port supports both GPON and XG(S)-PON access, thus allowing a smooth upgrade of bandwidth. At the user side, different optical network units (ONUs) can be deployed on demand, where they can form part of a mesh Wi-Fi network to deliver seamless whole-home gigabit coverage and enhance user experience. In this way, the existing GPON services will not be affected and there is no need to modify the existing optical distribution network (ODN).  

More than 30 operators around the world have collaborated with ZTE to test, trial and deploy the Combo PON solution. It has already become a preferred solution for operators to build 10G-PON networks.

Fixed-Mobile Convergence

The construction of a 5G network demands a large amount of optical fibers and supporting facilities, which incurs substantial initial investments. In a residential compound or office building where FTTH has already been deployed, the equipment room is restricted in space, making it unable to house additional stand-alone devices. There are also other challenges such as pipe laying, which requires the consent of the property owners, worries about the radiation risk posed by the base station, long construction periods and uncontrollable progress. If the FTTH resources including devices, fibers, pipes, equipment rooms and street cabinets can be reused, the 5G network can be built faster at a lower cost.

To reuse fixed network resources and accelerate 5G deployment, ZTE introduced the innovative Combo PON Plus solution based on Combo PON. In the solution, Combo PON Plus cards are inserted into idle slots of OLT, and one Combo PON Plus port carries five wavelength channels via one fiber. There is no need to change existing ODN. Active antenna units (AAUs) or GPON/10G-PON ONUs are deployed at the user side as needed to simultaneously provide FTTx and 5G service access over one fiber.

To exploit the full potential of copper infrastructure, ZTE also released a copper-based enhanced fixed wireless access (FWA) solution targeting at multi-story buildings. It utilizes G.fast technology and in-building copper resources to route 5G signals into homes in a low-cost, stable and reliable fashion.

IT-CT Integration

Some real-time services like online video, online gaming and interactive online teaching require very low latency and small packet loss. In an end-to-end network, there are usually several layers of equipment and bandwidth convergence occurs at every layer, leading to increased latency, uncontrollable jitters and bandwidth bottlenecks. It has become a trend to deploy computing capabilities closer to end users, which minimizes the uplink bandwidth bottlenecks and also meets the requirements of experience-sensitive services such as video.

Moving computing capabilities closer to end users means placing additional devices in the equipment room. This brings more pressure on power supply, heat dissipation and space provision. One workaround for this problem is to add computing capabilities to an existing device such as a PON OLT in the access office closest to end users, which addresses issues such as space occupation, temperature control, improves the resource utilization of the existing PON OLT, and significantly cuts the load on the upper-layer networks.

ZTE innovatively embeds 300 mm deep blade servers in a PON OLT to bring services closer to users, creating a better experience for services such as HDTV, 4K/8K video. For instance, some heavily sought-after video resources can be deployed in the built-in blade servers to reduce the latency and packet loss.

OLT Platform

Platform innovation is the basis of product and solution innovation. The capabilities of a platform determine its technical scalability and expandability. Making continuous efforts in platform innovation, ZTE has launched the ZXA10 C300, the only OLT in the industry that fully supports 10G-PON access in the past decade, and the TITAN, the industry's most powerful optical access platform that is based on a router architecture and fully-distributed forwarding.

Innovation opens up new business opportunities and helps generate new revenue streams. As a technology leader in the FBB field, ZTE has been driving the industry forward with innovations and will tap the full potential of fixed networks in the 5G era.