A testing time for mobile services

25 September, 2009

Mobile services are more popular than ever, and with the demand for rich media and data services growing, operators need to invest in better infrastructure to support this. This is highlighted in a recent study published by CCS Insight, which found that demand for, and use of, services such as Facebook and the BBC’s iPlayer is driving mobile data traffic for 16-24 year olds.

In today’s economic climate, mobile carriers need to seek more cost-effective backhaul technologies that also provide the flexibility to reach the required capacity levels. The biggest challenge for carriers is to deliver 4G while ensuring that costs do not spiral out of control. Mobile backhaul – the transmission of network data from the end user from wireless base stations onto the fixed line network, which carries the traffic over long distances not suitable for straight wireless transport – will play a big part in this.

Mobile backhaul is emerging as a major efficiency and cost savings deal breaker for mobile operators, cable operators and backhaul providers. At the core of this trend is the transition from TDM (Time-Division Multiplexing) to Ethernet which delivers better speed and reliability while also meeting stringent service level agreements (SLAs) at lower cost. The technology also allows operators to scale the capacity in their backhaul networks to accurately match the demand from mobile users, providing the efficiencies that operators require.

Increasing efficiency
As increasingly data-rich services are being consumed, however, a massive strain is being applied to the existing network, which will eventually buckle under the pressure. The infrastructure in place today was primarily built to carry voice traffic and to add the additional data and video traffic means additional backhaul costs. With voice the link between investment in backhaul and the carriers bottom line is clear, however with mobile broadband services the revenue generated vs. the cost of backhaul is not so linear. As carriers fight to gain customers through highly competitive pricing, their investment in backhaul eats into the revenue, and this needs to be avoided.

The need to save money while increasing efficiency when moving from TDM switched circuit environment to Ethernet/IP technology is paramount, whilst also ensuring the strict quality standards are met for service level agreements (SLAs). With 3G service usage already significant, and 4G services on the horizon, wireless carriers have no choice but to seek more costeffective backhaul technologies that also provide flexibility in reaching 100s of Gbps, thus delivering on the promise of 4G while avoiding cost inefficiencies.

Today most wireless backhaul traverses copper-fed T1s/E1s at a cost of approximately $150-$400 per month. Wireless operators currently must provide primarily voice services with defined revenues requiring small amounts of bandwidth – $0.10/minute using approximately 13 kbps of bandwidth per call. Revenue for a wireless operator tracks directly to bandwidth usage and ultimately backhaul charges.

Solutions need to provide end-to-end service turn-up and performance monitoring that is standards-compliant. This helps eliminate potential issues related to network element interoperability and upgrades. Operators need end-to-end visibility in the network to quickly identify problems, decrease mean-time-to-repair and avoid SLA penalties. Wireless carriers also need to include the support of TDM and Ethernet testing in a single system. This approach also reduces the OPEX costs of maintaining two network support systems simultaneously.

A number of test and measurement products and solutions to help providers resolve these issues are available, including JDSU’s NetComplete Service Assurance for Wireless Backhaul and its Smartclass Wireless Backhaul bundle. Solutions such as NetComplete give the service provider the control to rapidly turn-up services, eliminate wasteful dispatches with remote synchronisation and fast identification and fixing of faults in the network. In addition, JDSU’s Multi- Services Application Module is able to deliver a compact 10-Gigabit Ethernet (GigE) multifunctional tester to maintain and install carrier-grade Ethernet and internet protocol services. This allows technicians to test and upgrade their systems while out in the field, adding flexibility and speed of recovery from any network problems.

Evolving technology
The question is not ‘if’ but ‘when’ providers must update the backhaul network from TDM to Ethernet. Mobile backhaul service assurance is needed to address the management of Ethernet services for backhaul. When this transition occurs, it is important to understand the difference between the management of TDM and the management of Ethernet services for backhaul. Ethernet, for example, was not originally designed for carrier grade service use and this needs to be taken into account through a rigorous testing ethic while the industry waits for Carrier Ethernet to fully mature.

New standards are increasingly becoming available to bring Ethernet to this level, however not all network equipment vendors have implemented these across the board. Mobile operators need to translate these standards into a comprehensive OAM strategy including well-defined methods and procedures to effectively manage Ethernet services across the entire deployment lifecycle, from circuit turn-up to full service performance management and troubleshooting. By so doing they can gain an understanding of how to most effectively carry out standards-based testing and performance monitoring.

Operators are right to move to Ethernet backhaul, but they need to ensure they also evolve their testing approach to ensure the services deliver everything they promise.