Prospects of Fixed Broadband
As an important information infrastructure underpinning digital transformation, optical access networks are developing quickly thanks to the broadband strategies of different countries. The number of broadband users in China has surpassed 400 million with 100 Mbps access becoming mainstream by the end of 2018. The widespread use of broadband generates new services. A new generation of internet-based services featuring HD video, superior user experience, and cloudification drive increasing bandwidth demands. Currently, fixed broadband (FBB), characterized by gigabit-level bandwidth, millisecond latency and second-level service provisioning, is propelling the optical access network into a new stage of development.
Firstly, FBB is developing into a public infrastructure. With the rapid increase in bandwidth, the widespread use of FBB services and the gradual decrease of tariffs, users will become increasingly unaware of FBB's existence when they use it, although they do find it indispensable when it is not available. FBB becomes as integral as electricity, water or gas.
Finally, the core value of FBB is shifting from "bandwidth" to "experience". As broadband becomes a public utility, the previous business models centered on bandwidth-based charging are losing relevance. ICPs around the world are trying to grow the revenue with targeted experience packages and create extra business value through experience optimization.
Three New Features of Big Broadband
As the access network enters a new development stage, operators urgently need to build a new-generation access network—big broadband—that enables ultrafast speeds, convergence, and a premium experience.
It is inevitable for operators to continuously improve broadband speeds so as to deliver higher bandwidth services and gain a first-mover advantage in the fierce competition.
The life cycle of each generation of FBB technologies is about 10 years. The opportunities for gigabit networks have come. Home gigabit access technologies like 10G PON are starting to be commercially deployed and operators are considering building ubiquitous broadband access networks.
On the industry chain front, multiple gigabit technologies have matured with reduced costs, making them fit for scaled commercial deployments. Technologies such as XG(S)-PON/Combo PON/NG-PON2 can be deployed in the central office, FTTH or G.fast (if copper resources reused) on the user side, and gigabit Wi-Fi in the home, thus building an end-to-end gigabit network for new high-bandwidth services including 4K/8K, VR/AR, interactive video, and HD videoconferencing.
On the network construction front, considerations should be given to costs and smooth evolution capability. A 10 Gbps central office network can be built first. Combo PON solution can be deployed in the OLT to provide 10G broadband services while being compatible with existing GPON services. Terminals on the user end can be gradually upgraded to gigabit as needed. This approach both ensures the competitiveness of broadband and protects operator's investments. Combo PON is the best technology option for 10G PON deployment in both greenfield and brownfield scenarios. It fully reuses the existing frame and cable resources without the need for installing new frames and racks. Its fully integrated structure reduces equipment footprint. With Combo PON, GPON ONUs and 10G-PON ONUs can coexist, and the existing ONUs can be upgraded on demand. These help operators maximize their return on investment.
The future networks should be flexible, open and scalable to meet the increasingly high requirements put by new services. While telecom networks are tending towards a cloudified multi-tier data center architecture, the access network needs to provide capabilities of edge cloud infrastructure and enable NFV on the access side. Additionally, the arrival of 5G accelerates the convergence of services and networks. Users are concerned with service availability and experience instead of networks and access modes. The convergence of the existing fixed access and mobile transport networks will be an important direction for network development.
ICT convergence, as represented by SDN/NFV, has advanced rapidly in recent years. The stability of CT and the flexibility of IT will together make network architecture flatter and more open. In the future, networks will undergo a data-center-centric cloud transformation. The access network should follow this trend to implement phased virtualization. By deploying light-cloud blade servers in access equipment and turning them into the edge cloud infrastructure, operators can easily realize access-side VNFs, edge computing, and service provisioning closer to the users, thereby reducing pressure on the upper-layer networks and data centers.
As the 5G deployment accelerates, operators begin to plan 5G network construction. For greenfield and hotspot areas, operators favor the C-RAN architecture with centralized DUs. However, the current direct fiber connection solution for C-RAN fronthaul consumes considerable fiber resources, resulting in high deployment costs. Operators needs a highly efficient and reliable solution to address this problem. FBB has abundant fiber resources with tree typologies, and fixed and mobile networks naturally overlap in their coverage areas. Compared with the traditional direct fiber connection scheme, using WDM-PON to carry fronthaul services for 5G macrocells or 5G indoor distributed antenna system (DAS) saves trunk fibers by at least 90 percent. With 5G sharing the fiber infrastructure with FTTH/D applications, network construction costs can be reduced and network utilization improved. In residential communities where 5G wireless and optical broadband co-exist, FBB and MBB services can be deployed on demand. 5G+FTTH smart home gateways can be introduced to make FBB and MBB complement each other. The mutual backup between 5G and FTTH guarantees always-on broadband connection and enhances user experience.
As the user requirements for broadband networks are transitioning from high bandwidth to a superior service experience, more and more operators are making user experience a strategic priority and aligning themselves to an experience-centric operating model. Big Broadband delivers a premium experience from three levels: home network, access network, and O&M.
At the home network level, operators can launch smart home Wi-Fi networking service to provide seamless coverage with gigabit connectivity throughout the home. By adopting the "1+N" networking mode (a single smart PON gateway plus several wireless routers), operators can expand the coverage of the home network to completely solve the problem of poor coverage in the last 10 meters in the home, thereby laying the foundation for the rollout of more home services.
At the access network level, operators can use intelligent tools to improve the accuracy of data for optical network resources and the quality of optical links, thus guaranteeing the reliability of the gigabit broadband access network.
At the O&M level, intelligent analysis and management tools based on a cloud platform make the topology and connectivity of the home network visible while also allowing for remote optimization of Wi-Fi quality. The need to focus on users and services calls for the introduction of AI and big data analytics to harmonize services and networks for the O&M. This new mode of smart O&M enables the visualization and management of the quality of end-to-end services, identifies network fault location within seconds, and achieve a 100% accuracy in identifying users with poor QoE for proactive user experience optimization.
Ultrafast gigabit networks lay the groundwork for broadband operations, and it will be capable of refined operation that adapts to all scenarios and multiple services through IT/CT convergence, FMC upgrade, and service aggregation, further tapping the value of the existing networks. With the shift of focus to user experience, operators need to innovate business models to create a premium experience and more value for users. All in all, the next-generation access network will be ultrafast, convergent, and experience-centric.