RAD Helps China Telecom to Reduce Opex Costs, Accelerate Provisioning of Broadband Services to Millions of Subscribers

• Application
• - Media Conversion
• Challenge
• - To connect ATM switches with various types of fibre interfaces in the central office to ADMs on the SDH backbone (coax)
• Solution
• - RAD's AMC-101 universal media converter performs media conversion from single mode and multimode fibre to coax
• Benefits
• - High stability and reliability
• - Abundance of interface options
• - Cost-effective and easy maintenance
• - Modular interfaces enable field-changeable conversion between any two media

AMC-101 Media Converter Interfaces between ATM and SDH Equipment

Rolling out services to millions of subscribers is no easy task, particularly when competitive factors demand rapid deployment of access equipment and quick service provisioning. The problem is compounded when the subscribers reside in outlying areas, and it is difficult to know in advance the precise interface required to connect the central office equipment to the backbone network. Throw in the complexity of constantly changing network topologies and the installation of equipment from multiple vendors, and the resulting costs and delays in deployment and provisioning - not to mention the administrative difficulties - reduce competitiveness and cut into bottom line margins.

Converter Speeds Network Rollout

The above scenario was the challenge facing Guangdong Datacom Bureau (GDB), the provincial branch of China Telecom, which owns the fastest growing broadband network infrastructure in China. "When GDB plans its SDH and ATM infrastructure, it often doesn't know the specific interface requirements for each port at each node. Precise planning is time-consuming and difficult to achieve due to frequent topology changes. This delays the backbone equipment orders, in turn delaying network rollout," explains Stanley Tsang of Macroview Telecom, RAD's distributor in China and system integrator for the project. "GDB prefers to standardize central office equipment orders to one type of interface, and use converters where necessary. This avoids surpluses or shortages of inventory for specific interface types and enables quicker commissioning of the network," he continues. GDB provides value-added services to customers throughout Guangdong province, which is China's largest provincial market for such services. GDB provisions these high bandwidth services primarily over ATM links. ATM switches in the central offices are connected via high speed fibre to GDB's SDH backbone network. The ATM switches at the various sites employ a wide range of fibre interfaces, while the SDH add-drop multiplexers (ADMs) typically utilize coax interfaces. Accordingly, GDB sought a flexible conversion solution that would facilitate network deployment, regardless of the type of equipment in place at a given site.

Flexible and Reliable

The solution chosen by GDB was based on RAD's AMC-101 universal media converter. The AMC-101 is deployed between the ATM switch and the ADM, performing media conversion from single mode and multimode fibre to coax, and vice versa. The AMC-101 provides retimed or transparent conversion of optical and electrical signals for ATM, SDH/SONET and other protocols at data rates up to 155 Mbps. Moreover, modular interfaces of the AMC-101 enable field-changeable conversion between any two media. "The abundance of interface options supported by the AMC-101, as well as its totally modular design, gives the flexibility that is needed for the broadband network," says Tsang. "We have deployed over 200 AMC units in GDB's network with a negligible failure rate. The reliability and quality of the product are second to none," he concludes.