The attractiveness of deploying Fiber to the Home always been driven by the vision that fiber can provide unlimited capacity to offer a variety of services and applications. And technically this is true. But it is the PON systems themselves that drive the capacity and bandwidth that can be offered.
Historically, PON has been deployed as cost-effective means to offer residential broadband services. Key advantages of PON over other technologies includes a reduction in OPEX; a single optical fiber to support multiple users which results in less infrastructure and material costs than other point to point solutions. Additionally, PON allows for both asymmetric and symmetric services in support of a variety of market segments and applications as well as offering both the flexibility and scalability to support multiple services to a single end point.
While the initial focus of PON system has been residential broadband, the introduction of higher speed PON systems (starting with 10G PON), has made it possible to support a wide range of industry verticals and their associated applications. These higher speed PON systems offer operators the ability to deploy a converged architecture – a unified network for both business and residential services – such as residential, mobile, enterprise and more - onto one network.
This converged network ultimately spreads network infrastructure costs across all customers, from cost-sensitive home and SOHO subscribers to SLA driven corporations and enterprises.
Although operators are still in the transition phase of moving from GPON towards 10G PON, the rapid deployment of 5G mobile networks as well as the move towards cloudification is forcing operators to look beyond 10G PON at how best to support these (and more) applications.
In discussions with operators, the near-term drivers for PON systems beyond 10G include support for Enterprise Services, mobile backhaul, Industrial Applications as well as a wide range of next-generation applications.
Large enterprise organization are often characterized by the need to support connectivity between headquarters, multiple campuses, data centers and the cloud. This requires high-quality private lines supporting guaranteed bandwidth (up to 100Gbps), high-availability and low latency.
Depending on the vertical, the number of private lines and the bandwidth required of enterprise customers can vary quite significantly. For those enterprises that require 10Gbps or higher symmetrical services, the current 10G PON solutions will not be sufficient to meet these needs. This will require a higher speed 50G PON solutions. The use of a multi-PON combo cards will enable operators to offer both high-bandwidth enterprise services, while still supporting the needs of the residential market over the same ODN.
Other Enterprise related use cases include support for Passive Optical LAN – which is used to provide services in a multitude of building scenarios such as Office buildings, Stadiums, Apartment complexes, Hotels/Resorts, Retail centers as well as in support of services along Railways and Highways. 50G PON is suitable for all these scenarios.
Mobile networks offer significantly more bandwidth, but at the expense of distance. As such, new generation mobile networks will require more access points to offer the same coverage as before. How will this mass deployment of small cells be connected?
The point to multi-point nature of a PON network makes it a natural fit to support the higher bandwidth requirements and the densification associated with these small cells. As such operators have the opportunity to leverage their existing fiber-to-the-home (FTTH) network to support mobile transport and connect small cells. This eliminates the need for a dedicated mobile transport network and allows for better utilization of fiber assets, by leveraging the same ODN that is currently being used in support of residential broadband and reducing the total cost of ownership.
Bandwidth requirements of these dense networks will likely require connections of 10Gbps to 25Gbps, making it challenging for existing microwave connectivity and even newly deployed 10G PON networks. This presents an opportunity for the deployment of higher bandwidth 50G PON systems to meet future bandwidth requirements.
The modernization and automation of manufacturing processes will also require a more robust network that requires higher connectivity, reliability and stability. This will be necessary to support what is known as intelligent manufacturing which leverages the cloud for machine control as well as Big Data/Analytics, Autonomous Robots, Industrial Internet of Things, and Augmented/Virtual Reality to name only a few.
PON technology is a natural fit for implementation of a factory intra-plant network for communications within the factories as well as to the cloud, supporting manufacturing processes, surveillance and sensor networks, and office networks. PON networks, such as 50G PON will be able to support the bandwidth requirements for these scenarios.
The number of current and potential applications supported by higher-bandwidth PONs is vast. Additionally, when combined with software-defined access, operators have the ability to implement network slicing. By “slicing” the single physical network into multiple, virtual, end-to-end networks, an operator can software define the necessary performance criteria – such as speed, security, coverage area, etc. to match the requirements required by a service using the slice.
This level of flexibility opens up tremendous opportunity for operators to not only expand existing services, but also introduce new services/subscriptions.
The introduction of higher-bandwidth 50G PON technologies, enables operators to leverage their existing ODN, while enabling the expansion into new markets to offer new services and applications.
Next Steps: Focus on 50G PON
Operators across the globe are in the early stages of migrating to 10G PON through the implementation of Multi-PON combo cards supporting GPON/XGS-PON. While this migration towards 10G PON is expected to take 3-5 years, it is important for operators to begin the planning for beyond 10G PON.
It will be necessary for operators to assess the potential use cases and their associated bandwidth requirements, but also critically important to determine where in the network operators can leverage their existing fiber assets to extend services beyond the residential market.
Support for the mobile backhaul is likely to be the first major application for higher speed PON networks in support for small cell densification. As such operators should understand the projected growth of the wireless network within its service territory to determine necessary bandwidth requirements now and within 3-5 years.
It is likely that near term applications can be adequately supported with 10G PON solutions, however, at the current rate of growth, it may be necessary to examine the value of the next phase beyond 10G PON.
The ITU-T has settled on a single channel 50G solution as the next phase of TDM PON, supporting bandwidth configurations of 50G/50G, 50G/25G and 50G/12.5G (downstream/upstream). In addition, it will leverage the existing ODN and will offer coexistence with GPON and XGS PON.
Although there are solutions other than 50G PON, the competitive environment will be a key determinant as to timing. Additionally, depending on the planned supported use cases and their associated timing, operators will need to be careful in their migration plans or they may need to implement multiple network upgrades over the next few years, rather than taking a stepwise approach.
It is clear that 10G PON has opened up opportunities beyond residential broadband - offering
operators the potential for new, high-value revenue streams. The next step will be about choosing wisely beyond 10G PON. With 50G PON set to be the next global PON standards, this will likely be the mainstream choice after 10G PON.