Optical Bridges Above Thousands of Islands: PLDT Builds a Deterministic, Highly Reliable Network

The United Nations' 2030 Agenda for Sustainable Development explicitly calls for developing countries worldwide to expand access to information and communication technologies (ICT) and to build an inclusive digital future. In the Philippines, rapid population growth is driving surging demand for AI, cloud, and related digital services. As the country actively addresses frequent natural disasters, achieving sustainable digital transformation has become a central theme of national development over the past decade.

As a leading operator in the Philippines' communications industry, PLDT consistently implements a business-driven infrastructure building strategy that boosts competitiveness through technological innovation and service diversification while advancing the nation's digital transformation with a strong commitment to social responsibility and sustainable development. In partnership with Huawei, PLDT has established an all-optical network foundation featuring ubiquitous connectivity, real-time reliability, and intelligent sensing – powered by advanced optical networking technology – an infrastructure that withstands extreme environmental conditions and meets the demands of digital transformation. This initiative not only showcases F5G-A technology deployment in Southeast Asia but also exemplifies how technology can drive sustainable social development, offering an innovative model for developing nations worldwide to address the dual challenges of disaster resilience and economic growth.

Pain points: Challenges posed by frequent disasters and digital transformation

As a country located in one of the world's most disaster-prone regions, the Philippines experiences frequent communication outages due to typhoons. During disasters, numerous towns face prolonged communication blackouts. Amid the digital transformation wave marked by significant enterprise cloud adoption and widespread 5G deployment, demand for network reliability has seen a sharp increase, which is something legacy networks struggle to keep up with.

Communication outages not only disrupt daily life, but also hinder disaster response efforts, causing delays in rescue coordination and breaking data chains essential for post-disaster reconstruction. This undermines the United Nations' Sustainable Development Goal (SDG) 11 "Sustainable Cities and Communities" and SDG 13 "Climate Action". As the operator of the Philippines' largest fiber network, PLDT has experienced over 1,000 fiber cuts annually over the past five years due to natural disasters and road construction, resulting in frequent service interruptions and increasing customer complaints. Given these challenges, ensuring service reliability and maintaining service continuity in the event of fiber cuts has become a pressing issue for optical transport networks.

Technical foundation: Building a resilient and intelligent digital network

Through comprehensive analysis, PLDT has identified two major issues that affect network reliability. First, the network mesh degree is insufficient. The existing backbone network relies on a limited number of key nodes or specific optical fibers and lacks a robust multi-node, multi-path backup mechanism. As a result, the disconnection of a critical optical fiber will inevitably lead to service interruptions. Second, service protection capabilities are insufficient. Although protection paths are configured for some mission-critical services, traditional protection schemes can only address single-point failures. In extreme scenarios such as natural disasters, where multiple points of failure may occur simultaneously on the network, traditional protection schemes are unable to meet service continuity requirements.

To address these issues, PLDT is partnering with Huawei to implement a comprehensive network resilience enhancement plan. This plan is rolled out in two phases. We have taken a two-pronged approach in Phase 1. First, multiple network links and core dual nodes are added to improve the network mesh degree and ensure that critical paths support service restoration. Second, the industry's most advanced automatically switched optical network (ASON) protection technology is deployed to provide 1 (working path) + 1 (protection path) + R (restoration path) protection for critical services. Upon the first failure, services are switched from the working path to the protection path. When the failure occurs again, services are switched from the protection path to the restoration path – all within less than 50 ms. This solution enables PLDT to maintain service continuity even during multiple fiber cuts, shortening the service recovery time from minutes to milliseconds and ensuring 99.995% availability. In addition, the solution supports 24/7 meter-mounted tests without bit errors, meeting the industry's highest standards and significantly improving user experience.

Evolution: Building a deterministic and highly reliable optical network

In the second phase of the resilience enhancement plan, PLDT is working with Huawei to continuously optimize the network architecture and O&M efficiency based on the Transmission Digital Map of Huawei's iMaster Network Cloud Engine - Transport (NCE-T) solution. This solution has transitioned the network O&M from reactive repair to proactive prevention.

Automatic identification of potential risks and proactive network assurance: iMaster NCE-T conducts multi-dimensional monitoring across fiber, optical, electrical, and service layers to detect risks such as fiber degradation and working/protection route co-cable or co-node in disaster-prone areas. It automatically generates risk heatmaps to help maintenance teams carry out preventive reinforcement before disaster seasons, transforming traditional post-disaster repairs into proactive fault prevention.

Remote fault locating for quick network recovery: Due to typhoons, construction, and other man-made events, optical cables may be bent or broken frequently. Previously, after a fault occurred, PLDT had to deploy multiple teams to the line side, equipment rooms, and user locations to identify and locate failures with instruments. Now, using the Embedded Optical Time Domain Reflectometer (eOTDR)-based fast fault locating solution which is accurate to meters, engineers can remotely and quickly locate faults. Only one team needs to be dispatched to the site to rectify it. The fault locating time is shortened from hours to minutes, significantly accelerating the speed of service recovery and driving down OPEX.

Through these two phases of resilience enhancement, PLDT has established an end-to-end reliability system of "Prevention - Resilience - Healing", further improving service availability. It has built a highly resilient optical network and created a digital defense line against disasters. This ensures uninterrupted communication during disasters while reducing manpower and material costs, freeing up resources for post-disaster reconstruction and livelihood assurance, and fostering a positive cycle of technology investment and social value.

PLDT firmly believes that the deterministic and highly reliable network based on F5G-A not only ensures " always-on services during fiber cuts", but also serves as a key driver for digital transformation. When every video call from Mindanao fishermen is connected without interruption, when every telemedicine support reaches disaster-stricken hospitals in Manila with precision, and when the Philippines' digital economy flourishes along fiber lines – intelligent optical networking technology moves beyond abstract code. It becomes the golden thread that strings countless "Salamat po (thank you)" into pearls of progress for our era.