Naveen Bhat, VP and GM for Asia Pacific at Ixia, explains the new test and measurement parameters that LTE brings to the table
T&M: What new test parameters does LTE bring to the table that operators need to watch for?
Naveen Bhat: For a start, user expectations for service quality on cellular networks are increasing greatly. Test solutions to measure quality of experience (QoE) are in high demand. Operators are very concerned with having the best possible user experience compared to their competitors.
Also, the adoption rate of smartphones and tablets is very high. This is driving the scalability requirements on networks and in parallel driving a large increase in the scale of test beds. Operators need to scale test labs to hundreds of gigabits of traffic from millions of subscribers.
LTE networks are all IP, with integrated voice and data, instead of using a separate network for voice. This drastically changes the challenge and complexities of testing. More than ever, operators need to emulate the complex combination of applications that will be carried over their networks.
Another key difference between 3G and LTE is that 3G networks for the most part do not have the ability to offer differentiated services (QoS). LTE network specifications are very advanced in this regard, but the technology to pull it off and the approaches to validating this are complex.
What new complexities does Wi-Fi offload introduce to the testing process?
More and more, QoS is being implemented in Wi-Fi networks. But a lot of the operator testing is only looking at RF signal strength with "site surveys". This testing does not put real traffic over the networks or test under heavy load. This means that a lot of guesswork is made in terms of the actual quality users will have on the network. Operators that are doing thorough testing and sending real traffic over Wi-Fi networks stand a much better chance of ensuring users will not see a drop off in quality as traffic switches from cellular to Wi-Fi.
How has LTE changed testing for network monitoring, especially in multi-access/multi-service scenarios?
LTE is growing in both complexity, as both voice and data begin to be carried over LTE, and in density as more subscribers are demanding reliable high-speed access. Customers are also increasing their reliance on LTE, making it a business-critical service for operators. As these changes occur, reliable network monitoring becomes crucial to operator efficiency and reliability to ensure quality of service, but to also validate new technologies such as multi-access and VoLTE as they are deployed and change the nature of the traffic on the network. Network monitoring is a critical tool to allow for reliable and repeatable monitoring that is no longer simply capturing data, but also intelligently responding to network events, validating new architectures, and improving both service levels and security in a dynamic monitoring environment.