IPTN Brings a Green Bearer Network

Today, environmental friendliness, energy conservation, and consumption reduction have become a global consensus. The best way for a telecom operator to reduce its OPEX is to build a green network, which is also the major trend of future telecom networks. A green network helps to cut tariff rates, reduce environmental pollution, and thereby benefit subscribers. With the development of energy conservation technologies, the telecom industry is stepping into a green era. 

Core Concept of IPTN

With the deployment of 3G networks and implementation of full-service operation strategy, the IP-based telecom services place higher requirements on the bandwidth, scheduling, flexibility, cost, and quality of bearer networks. In response to the IP-based tendency, ZTE has launched its new-generation IP-based Packet Transport Network (IPTN) solution (see Figure 1) that uses the open and unified packet switching platform to carry multiple services, and integrates the synchronization clock, carrier-class OAM, and protection functions. It is an end-to-end bearer network solution covering the access and convergence layers and completely catering to the full-service scenario needs of Mobile Backhaul and FMC.

The IPTN solution fully considers the operators’ needs for building green bearer networks. It can provide low CAPEX and OPEX while meeting the increasing bandwidth needs. Its green concepts are characterized by:

■    Energy saving and environmental friendliness: It uses smaller-footprint IPTN products that consume fewer resources and emit less harmful gas, effectively reducing OPEX.

■    Efficient OAM: It adopts carrier-class OAM technologies and an intelligent network management platform to offer refinement management and easy operation and maintenance, which can improve maintenance efficiency and lower OPEX.

■    Network security: It supports multiple network protection mechanisms and provides high-accuracy time synchronization capability, satisfying the need for a substitute for GPS while completely improving network security and lowering CAPEX and OPEX.

■    Evolution with Investment protection: It supports integrated TDM/ATM/Ethernet/IP bearer mode to protect existing network investment; adopts a scalable technical platform that can satisfy the needs for smooth standard and service evolution while lowering CAPEX.

Optimized Design for Energy Saving and Environmental Friendliness

The initial design of ZTE’s IPTN products is carried out for energy saving and emission reduction, aiming to minimize their pollution to the environment.

The IPTN product adopts ZTE’s self-developed lower-consumption chip that supports the dormant/standby mode. It uses the Automatic Power Control (APC) technology and supports variable-speed fan control. In addition, it provides intelligent and dynamic adjustment of power consumption that can reduce useless power consumption in the equipment. In the verification test for China Mobile’s IP-based MAN transport networks conducted in 2009, the power consumption of ZTE’s IPTN products was simply one-third of the average power consumption of their kind in the industry.

Due to the compact design, the IPTN product is small in size and low in power consumption, bringing about effective space and power savings. ZXCTN 6100 is the most compact packet transport network platform that is commercially used at the access layer. It is only 1U in height, and thus adapts to the base station access environment flexibly.

The IPTN product fully complies with various international standards on environmental protection. Its hardware platform is packed by leadless and degradable materials, complying with the RoHS requirements and Management Regulations on Pollution Control of Electronic Information Products. In addition, ZTE implements the green certification for suppliers, and has signed a letter of commitment to environmental friendliness with them.

SDH-like OAM

ZTE’s IPTN products can save time and reduce difficulty in OAM. They inherit the OAM features of SDH, such as hardware-based hierarchical OAM, complete performance and alarm detection on pseudo wire, tunnel and section layers, fast location of the faults of different levels, carrier-class end-to-end management and cascaded monitoring, and high network availability.  

Furthermore, they use the unified intelligent network management platform (NetNumen T3) that can implement centralized management of SDH/MSTP, ASON, WDM, and OTN, and provide NE management and user-friendly interfaces for easy end-to-end service  configuration and management.

Guarantee for Network Security

ZTE’s IPTN products have multiple protection solutions, achieving the carrier-class reliability of 99.999%. The redundancy backup is provided for key components at the equipment layer; the Link Aggregation (LAG) and IMA protection functions are provided at the client side; multiple protection modes are supported at the network layer. In addition to Label Switched Path (LSP) protection and Sub-Network Connection Protection (SNCP), ZTE’s IPTN products are the first of their kind to implement the connection-oriented T-MPLS ring network protection (see Figure 2). With its protection switching time less than 50ms, the T-MPLS ring network protection is reliable and similar to SDH Multiplex Section Protection (MSP) that can avoid LSP protection congestion caused by fiber interruption. This kind of ring network protection has the advantages of simply configuration and high efficiency, which are prominent especially when there are a huge number of LSPs. Its OAM is based on section detection that can save more resources than that of tunnel protection.

ZTE’s IPTN products provide industry-leading time synchronization capability. Most vendors in the industry adopt only the IEEE 1588v2 for time synchronization. By leveraging the advantages of various packet synchronization technologies, ZTE took the lead to propose its unique Ethernet time synchronization solution, that is, to implement the IEEE 1588v2 time synchronization based on the synchronous Ethernet and accurately insert or pick up the timestamp through hardware so as to effectively reduce the 1588v2 packet sending frequency and speed up the convergence. The solution has advantages of high accuracy, high compensation, and high reliability. Using the SSM or BMC protocols, it can implement automatic protection switching of the time links to guarantee reliable transfer of time signals and satisfy the need for a substitute for GPS.

In April 2008, ZTE became the sole vendor to start cooperation with China Mobile on the PTN-based GPS substitution, and worked out the Technical Specifications for PTN-based Time Synchronization and Research Report on the Feasibility of GPS Substitution in TD-SCDMA System. In August 2008 in Shenzhen, China, ZTE completed interconnection with the TD-SCDMA base station and the stress test for PTN-based time synchronization for a total of  35 nodes. The test results turned out to be successful, fully conforming to the requirement of TD synchronization. In China Mobile’s TD-SCDMA network trials in Shenzhen and Nanjing in 2009, ZTE adopted its IPTN solution to transfer time synchronization signals instead of GPS clock signals of the base station. The test results were highly accepted by China Mobile, lying a solid foundation for future large scale commercial use.

Multi-Service Bearer Platform for Investment Protection and Smooth Evolution

ZTE’s IPTN products provide abundant interfaces including FE, GE, 10GE, STM-N (CH, POS, and ATM), TDM E1, and IMA E1, and adopt the PWE3 technology to support integrated TDM/ATM/Ethernet/IP bearer mode, completely satisfying the needs of various service networks while keeping compatible with existing non-IP base stations to reduce CAPEX.

The IPTN products use a scalable technology platform that can support smooth evolvement of MPLS-TP standards through software upgrade. Its hardware follows the modular design concept; its core nodes enable high bandwidth reservation; and its ports can be smoothly upgraded to 40G/100G, thereby catering to the needs of bandwidth expansion and smooth network evolution.

Conclusion

ZTE has always adhered to the concept of environmental protection, and put it into practice. Its IPTN products can help operators build their advanced green bearer networks from the aspects of energy conservation, environmental friendliness, OAM efficiency, network security, and investment protection. ZTE is working closely with its partners worldwide to embrace the green era of the telecom industry.