A long history, the stunning Alps, the blue Danube and the music in the streets have made Austria, a country in the center of Europe, a world-famous tourist destination. Austria is also a key destination for European multinational operators, as T-Mobile Austria (hereinafter referred to as "TMA") is the second largest mobile operator in Austria and a wholly owned subsidiary of Deutsche Telekom AG, with 4,076,000 subscribers in Austria.

Deutsche Telekom Group officially took control of TMA in 2001, and after years of operation, TMA has achieved rapid development. High-speed business development has brought the pressure of transmission network upgrading, TMA's original backbone network expansion costs are expensive, and operation and maintenance costs are high. On the other hand, with the development of data services, the transmission bandwidth of the original network is getting tighter and tighter, which greatly restricts the long-term development of TMA and creates huge business risks.

TMA Backbone Optical Network Requirements

TMA's existing DWDM network is not satisfactory in terms of system capacity and network reliability, and TMA wants to build a new DWDM transmission network, which is a mesh-based network based on the ROADM system, as the long-term goal of network construction. Specific solutions include multi-dimensional sites with tunable OTUs (Optical Transponder Units) that can support any customer-side signal assignment to any wavelength, in any direction. According to these demands, with the increase of node dimensions, service commissioning will become complex, and how to quickly deploy services and flexibly schedule wavelengths/sub-wavelengths in mesh networks will become a new challenge.

Considering the bandwidth demand from future service growth, TMA hopes to deploy 100Gbps transmission network in its network after the standard of IEEE 802.3ba is perfected in 2012. Since there are only 10G services in the current network, it is necessary to consider the smooth compatibility of 100G in the newly built 10G network. In other words, after the services are upgraded to 100Gbps, there is no need to add or change existing amplification and relay sites, and there will be no impact on the protection and restoration of connectivity in the existing network.

For backbone layer transport networks, network reliability is critical. In addition to traditional protection mechanisms, TMA requires the ability to dynamically reroute services after a network failure, as well as the ability to handle secondary network failures.

Construction of future-oriented backbone optical network

The TMA backbone network construction project is divided into three phases, of which the first phase builds eight sites on a chain to carry end-to-end 2D services, and completed the service cutover in November 2010 ahead of schedule. In the second phase, the whole network is transformed and upgraded, including 29 ROADM sites to realize mesh-based intelligent network, and the cutover was completed in December 2011. Phase III will realize capacity expansion and provide 100G transmission bearer capacity. The successful cutover of the first and second phases of the project ahead of schedule demonstrates ZTE's excellent delivery capability and lays the foundation for the success of the third phase of the project.

According to the rapid development of TMA services, ZTE deployed ROADM sites with "any direction, any wavelength, any rate" scheduling at nine core sites in Vienna, Salzburg, and Innsbruck.

ZTE Corporation customizes to meet the TMA's demand for network reliability by providing a solution based on the combination of GMPLS control plane protection and dynamic rerouting, which meets the TMA's demand for unaffected services in the event of secondary failures by means of a primary protection and secondary recovery mechanism. At the same time, different levels of QoS services are provided by dividing the service levels, so as to realize the reliability of carrier-grade services while taking into account the cost of network construction.

In response to mesh networking requirements, ZTE provides the WASON control plane, which realizes topology auto-discovery, automatic routing and signaling exchange functions, as well as automatic creation of service connections, fast end-to-end configuration, and traffic control. The intelligent service wavelength scheduling solution improves the utilization of network resources and reduces operation and maintenance costs.

In response to the TMA's large number of GE/STM-16 and 10G service demands, ZTE deploys a solution that combines OTN electrical crossover and ROADM optical crossover, realizing flexible service scheduling based on the unity of optical and electrical.

In order to realize the smooth upgrade of the network to 100Gbps, ZTE Corporation refers to the 100Gbps optical transmission line design principles during the network design stage, so as to realize the subsequent smooth upgrade from 10Gbps to 100Gbps and eliminate the impact on the existing network services.TMA and ZTE Corporation are working together to conduct laboratory tests and on-site verification of the 100Gbps transmission technology, and will ultimately deploy the 100Gbps transmission technology in the third stage of the network construction. TMA and ZTE are working together on laboratory testing and network validation of 100Gbps transmission technology, and will eventually deploy 100Gbps services in the third phase of network construction.

Joy of Success

In March 2012, all services of the second phase of TMA's backbone wavelength division project were cut over and operated stably, receiving praise from the operator, and Mr. Rüdiger Köster, CTO of TMA, commented: "ZTE was able to customize product features for us and provide us with an industry-advanced optical transmission solution, while saving a large amount of maintenance manpower and significantly reducing operation and maintenance costs. Mr. Köster commented, "ZTE was able to customize the product features to provide us with an industry-leading optical transmission solution. With the introduction and deployment of WASON, network reliability is up to 99.99%. At present, the operation of the equipment in the whole network is very stable, and it has smoothly entered the balanced operation stage."

On June 12, 2012, the WASON intelligent OTN network solution adopted in the TMA project won the "Backbone Optical Network Innovation Award" from GTB (Global Telecom Business), an authoritative media in the international telecom industry. The award signifies that the backbone optical network deployed by TMA using ZTE's WASON technology leads the industry.

In October 2012, the 100G test bureau was deployed in the existing network link and successfully passed all test entries.

In November 2012, 100G commercial cutover was successfully completed. In 2013, TMA will complete the commercial scale of 100G network.