CurbPON accelerates full-fiber network transformation from copper lines

2020.02.17 By Lei Bo, Product Executive of Copper, Access Network Domain, Huawei

After analyzing the characteristics of live copper networks, Huawei developed CurbPON to maximize the value of copper sites and quickly and cost-effectively deploy FTTH networks. Currently, many operators have used or plan to use CurbPON to reconstruct outdoor sites, build FTTH networks, and boost the coverage of optical networks. 

CurbPON

Copper line networks were the first generation of networks in broadband history. Many copper resources are still in service in the world, mainly in the form of fiber to the curb (FTTC). Currently, 1.5 million outdoor sites provide broadband services to more than 240 million home users and enterprises.

In the gigabit era, new services such as cloud VR, cloud gaming, and 8K TV require bandwidth of more than 200 Mbps and sub-20-ms latency. FTTC networks encounter bottlenecks, and so fiber to the home (FTTH) is the preferred choice of governments and operators across the world. Many countries in the world have set up national strategies to promote full-fiber networks. For example, the UK plans to invest more than £13 billion pounds in fiber infrastructure; France has set the ambitious goals of achieving 80 percent FTTH coverage by 2022 and 100 percent FTTH coverage by 2025; and Thailand has released a US$430 million national broadband bidding plan focusing on fiber broadband network development. 

Challenges hamper traditional FTTH network construction 

During FTTH network deployment, applying for ROW, trenching, burying cables, and deploying drop cables can be very complex due to property ownership. Many operators haven’t made great progress after years of fiber network construction: Building an FTTH network in the traditional way takes 6 to 9 months and the E2E construction cost per line exceeds US$400. FTTH is five times the cost of FTTC and the construction period is seven times longer. Huge investment and long construction times slow down the deployment of optical networks, hampering the development of the broadband business.

Another major challenge for traditional FTTH construction is reaching remote areas, as doing so requires the deployment of ultra-long feeder fibers between 10 km and 30 km that cost two or three times more than FTTH construction in urban areas. The huge difference in ROI has dissuaded many operators from launching fiber construction plans in remote areas.

To boost FTTH development, Huawei has developed a new network construction method, especially for operators with many copper resources and outdoor sites. In a typical FTTC network, each of these sites has an independent power supply system and upstream optical cable with 4 to 8 cores. The average distance between these sites and central offices (CO) is about 10 km, but the distance between these sites and end users is just 300 to 500 meters. If an FTTH network can reuse FTTC resources and provide PON service ports from outdoor sites, the feeder fibers from the CO to outdoor sites are ready for use. Only drop cables need to be deployed between these sites and residences, covering a few hundred meters. Since FTTC sites deliver broad coverage, this solution addresses optical network coverage in remote areas.

However, the deployment of OLT in FTTC sites still faces two challenges. First, the space of outdoor cabinets on the live network is limited. Although the power supply and number of upstream fibers meet the needs of the OLT, there isn't enough room to install components such as the OLT and optical distribution frame (ODF). Second, with the OLT moved downwards, the number of devices increases sharply, raising requirements for automatic device O&M and service provisioning.

CurbPON for FTTH network construction

After analyzing the characteristics of live copper networks, Huawei developed CurbPON to maximize the value of copper sites and quickly and cost-effectively deploy FTTH networks. This solution has the following major benefits:

The Mini OLT is closer to users and saves feeder fibers: The Mini OLT is installed in FTTC outdoor cabinets on the live network. Only 2U space is required to cover 2,000 users (32 PON ports + 1:64 optical splitting). In addition, Flex-PON is supported to smoothly evolve to 10G PON in the future. The power consumption of a Mini OLT is less than 300 W, while at a site the power used generally exceeds 2,000 W. Therefore, power supply isn’t an issue for the Mini OLT. Of the original four or more upstream fibers, two can be used for the original devices and two can be used for GE/10GE upstream transmission of the Mini OLT. This solution saves using feeder fibers, which are 10 km long on average from COs to outdoor cabinets, and reduces the ROW, trenching, and cable burying workload by 70 percent.

The SideBox on original cabinets expands space for the Mini OLT and ODF: A SideBox can be mounted on one side of an original cabinet to address the space problem. It’s designed for quick installation and can be installed using screws in one day without drilling holes or requiring soldering. The expanded space can be used to house a Mini OLT and an ODF that supports 32 fiber cores. The contact surfaces of the SideBox and the cabinet are designed to be waterproof and meet IP55 protection requirements.

DQ ODN for fast drop cable layout: In the drop cable section, staffing and construction efficiency are bottlenecks. Professional technicians need to carry expensive and bulky fiber splicing tools to splice each fiber, which takes more than 10 minutes. With the DQ ODN end-to-end pre-connection solution, customized optical cables support plug-and-play and fiber splicing is not needed, reducing the construction period of the drop cable section by 30 percent and costs by 15 percent.

Automatic device configuration and service provisioning on iMaster NCE: After the Mini OLT is powered on and connected to the network, the iMaster NCE automatically delivers management configurations to complete OLT authentication without any onsite software commissioning. Using the Optical AI (OAI) board deployed on an OLT, the iMaster NCE can automatically and remotely check and accept the ODN network, eliminating the need for manual line-by-line acceptance. In addition, the iMaster NCE can abstract and manage service APIs in a unified manner. During service provisioning, nodes do not need to be configured one by one – services can be provisioned with a single click, shortening the provisioning time by 80 percent.

CurbPON boosts ROI

Using CurbPON, operators can reduce FTTH construction costs from US$400+ to US$300+ per line and shorten the deployment period from 6 to 9 months to 3 to 4 months, greatly accelerating project progress. Currently, many operators have planned to reconstruct outdoor sites to build FTTH networks and have used CurbPON to accelerate the coverage of optical networks.

Based on the fast deployment of FTTH networks, operators can release optical broadband packages with a bandwidth of over 300 Mbps, which significantly increases the tariff by more than 40 percent compared with the original packages. In addition, operators can upgrade their video services based on gigabit broadband to provide users with a new ultra-HD video experience, bringing value-added revenue of US$10 to US$20 per household per month. 

Thanks to the quick rollout of full-fiber gigabit broadband networks, operators can expect rapid growth in fiber broadband revenue. In addition, the fiber infrastructure network built with CurbPON is capable of smoothly evolving to 10G PON from COs to end users in the future. This consolidates operators’ competitive advantages in next-generation access networks. 

CurbPON will help more copper line inventory markets maximize the value of sites, enable the fast and low-cost deployment of FTTH networks, and bring gigabit full-fiber networks to thousands of households.