Recently, Zhoushan Branch of China Mobile Zhejiang Co., Ltd. (hereinafter referred to as Zhoushan Mobile) and Huawei successfully built an innovative AirPON commercial site in Zhoushan Islands, Zhejiang, China. Using the latest Huawei AirPON solution featuring the CO+X network architecture, the site deploys one optical line terminal (OLT) in the central office (CO) on Shengsi island, and deploys remote slave OLTs on nearby islands. The remote OLTs are centrally managed as virtual extended subracks of the master OLT. This innovative architecture simplifies network construction and O&M while preventing frequent NE disconnection, realizing fast and simplified network construction and O&M on the islands.

Zhoushan City is located in the northeast of Zhejiang province and consists of 2085 islands. Due to varying sea conditions, it is difficult to deploy and maintain submarine optical cables for these islands, and residents on these islands have limited network access. Zhoushan Mobile has made strenuous efforts and a host of innovations to build a premium wired network along with a wireless 5G network for Zhoushan. After conducting a survey on Shengsi and Lvhua islands, Zhoushan Mobile found that submarine optical cables are vulnerable to external factors, resulting in frequent NE disconnections. In addition, to carry out onsite network O&M, engineers need to take a ferry to reach the islands, which is labor intensive and inefficient. In this context, Zhoushan Mobile needs to quickly build a reliable network that can be remotely maintained, so that residents of Zhoushan City can enjoy premium home networks.

Zhoushan Islands, Zhejiang Province, China

Based on the survey results, Zhoushan Mobile chose Huawei’s AirPON solution with the CO+X architecture to reconstruct the island network. In this solution, a master OLT is deployed in the CO on the Shengsi island, and slave OLTs (X in the solution) are deployed in nearby islands such as Lvhua to fully reuse existing sites and realize fast deployment. Using the CO+X aggregation management technology, remote slave OLTs are aggregated to the CO over the live slicing packet network (SPN) and managed as virtual extended subracks. In this way, the master OLT can directly deliver service configurations to slave OLTs, and upgrades can be performed remotely. This effectively eliminates the need for onsite software commissioning and O&M.

CO+X networking diagram

The AirPON commercial site in Zhoushan has the following innovations:

Huawei AirPON series slave OLTs can be installed on rooftops, poles, towers, or outdoor cabinets to reuse existing sites, and are backhauled to the master OLT in the CO over the live network without routing new submarine optical cables. This solution prevents network interruptions caused by unstable submarine optical cables, facilitates flexible and fast device installation, and makes network construction efficient and economic.

Compared with the traditional network architecture in which many NEs are managed separately, the innovative CO+X architecture uses one master OLT in the CO to manage up to 15 remote slave OLTs as virtual extended subracks, reducing the number of NEs requiring separate management. In this architecture, service configurations are stored on and delivered by the master OLT, upgrades can be performed remotely, and no service needs to be configured onsite on slave OLTs. As a result, network deployment and O&M are simple and efficient.

Due to complex geographical environments, deploying networks on islands is much more challenging than on the mainland. In this project, for example, remote equipment rooms are built on mountain tops where devices have to be carried to the sites by workers, making construction work difficult. In the CO+X architecture, the master OLT has a built-in DHCP server. The remote slave OLTs support plug and play, and require no independent IP addresses or local software commissioning. In the future, the CO+X architecture will be able to interconnect with a new ODN without fiber splicing, realizing digital and efficient network construction for Zhoushan.

Thanks to the concerted efforts by Zhoushan Mobile and the Zhoushan Government, this project was successfully delivered, providing premium home network services for residents of Zhoushan. In the future, Zhoushan Mobile will work with Huawei to explore more innovative network construction techniques, and extend the CO+X network coverage to all islands of Zhoushan to simplify network construction and O&M while providing high-quality network services for residents.