PTN Commercial Deployment Timing Is Ripe
In recent years, the focus of communication technology development has shifted from voice to data. With the continuous maturation of new markets such as LTE, triple play, and cloud computing, all-IP has become the trend for service network development, evolving from service IP-based to interface IP-based and then to core IP-based, placing new demands on the transport network.
With the rapid development of emerging data services, continuous bandwidth growth, the IP-based evolution of wireless services, and the application of VPN services for commercial customers, comprehensive requirements on the bearer network in terms of bandwidth, scheduling, flexibility, cost, and quality are increasingly stringent. Traditional SDH networks based on circuit cross-connection suffer from high costs, low bandwidth utilization, and insufficient flexibility, leaving operators caught in the contradiction between meager revenue from bandwidth-intensive data services and high network construction and maintenance costs. Meanwhile, traditional IP networks and products with non-connection-oriented characteristics find it difficult to strictly guarantee the transport quality and performance of critical services, making them unsuitable for carrier-class service bearing.
The existing transport network has several major drawbacks: first, the application scope of TDM services is gradually shrinking; second, with the continuous increase in data services, the data switching capability of MSTP-based equipment can hardly meet demand; third, the bursty nature of services is becoming more pronounced, and the rigid transport pipes of MSTP equipment will lead to reduced bearing efficiency; fourth, with increasingly stringent carrier-class service requirements, traditional networks based on Ethernet, MPLS, ATM, and other technologies cannot simultaneously satisfy the demands for QoS, reliability, scalability, OAM, and clock synchronization.
Therefore, operators need an IP transport network that can simultaneously meet the requirements of traditional voice services and carrier-class services, reduce operating costs and capital expenditures, and build an intelligent, converged, broadband, and comprehensive sustainable carrier-class network. This is how Packet Transport Network (PTN) emerged.
PTN is the product of combining MPLS, Ethernet, and transport network technologies. It features connection-oriented transport characteristics and is suitable for bearing high-quality multimedia data services such as wireless backhaul networks, Ethernet private lines, and IPTV for telecom operators. PTN establishes a layer between the underlying optical transport media of IP services, designed specifically for the bursty nature of packet service traffic and the requirements of statistical multiplexing transport. With the packet as its core, it enables multi-service bearing, offers lower total cost of ownership, inherits the traditional advantages of optical transport—including high availability and reliability, efficient bandwidth management mechanisms and traffic engineering, convenient OAM and network management, and high scalability and security.
In summary, PTN is characterized by an all-IP packet-based core, featuring SDH-like end-to-end connectivity, high performance, high reliability, ease of deployment and maintenance, robust network management capabilities and user experience, while integrating many advantages of IP services and adopting a layered network architecture.
These characteristics align well with the current network and service development needs of operators. After years of exploration, key issues concerning PTN development have been preliminarily resolved, and the timing for large-scale PTN commercial deployment is now ripe.
In terms of driving forces, the transformation brought by data services is the greatest driver for PTN commercialization. The trends toward service personalization and broadbandization have accelerated the pace of network IP-based evolution, providing valuable development opportunities for PTN. In terms of supporting resources, the low utilization of fiber optic cable ducts is a major obstacle constraining operator service development. With the advancement of FTTH and LTE, this issue will become even more prominent. PTN can effectively address existing fiber duct problems and maximize the utilization of duct resources. In terms of industry chain development, in recent years nearly all mainstream equipment vendors worldwide have been engaged in PTN R&D and commercialization efforts. The collective efforts have brought PTN technology, standards, and applications to a basically mature stage, and the growing PTN industry chain has laid the foundation for large-scale commercial deployment. Furthermore, issues concerning PTN operations, maintenance management, and network construction models have also been effectively resolved. Many vendors have now launched a series of commercial PTN solutions, some of which have already been deployed commercially overseas and achieved favorable application results.
Packet transport technology follows two development routes—PTN and IP RAN. PTN is designed based on transport concepts, while IP RAN is designed based on data communications concepts. Similar application scenarios give them consistent evolution goals. Currently, the industry debate over the relative merits of PTN versus IP RAN continues. In fact, both have their own characteristics and advantages. The commercial effectiveness of a technology depends not only on the advancement of the technology itself but also on factors such as industry chain maturity, cost, and application models. When selecting a specific technology, operators should proceed from their own network and service conditions and rationally choose the evolution path of the transport network.