By Michael Lawton, Product marketing engineer, Wireless division, Agilent
When people talk about the digital life, they usually refer to mobility and content. But neither of these benefits is possible without a reliable and feature-rich wireless device. It is the test engineer who makes sure that all the software and hardware components in these complex devices work together. The role of the test equipment supplier is to make the work of these engineers as easy and productive as possible.
Delivering digital services in a mobile environment is challenging, and the demand for multimedia applications is driving technology to ever higher data rates. Modulation formats such as 1xEV-DO, EDGE, WCDMA, and HSDPA are becoming the norm.
In the R&D lab, engineers have to verify that their implementations of these technologies meet industry standards before releasing a new wireless device into manufacturing. They also have to thoroughly test the many applications now embedded in the device and ensure that it performs well at maximum data rates, even if these rates are unlikely to ever be achieved in an operating commercial network.
Traditionally, design engineers test software and hardware separately. They use scripting solutions to develop the protocols and RF-based tools to test physical-layer components. Everything comes together at the integration and verification stage, however, when the complex inter-workings of software and hardware must be tested as realistically as possible in a network running data traffic.
According to engineers, integration can be a painful business. Each problem they identify must be solved before they can move on to the next step. Solving one problem often leads to uncovering another. Test engineers can't just verify part of a chipset, for example, when they know that an elusive problem still exists. And whenever they modify firmware or software for any reason, they have to do regression testing to measure the effects of the change.
A range of commercial test equipment, specifically scripting engines, RF parametric testers, and stack-based signaling testers, address the various aspects of integration and verification testing. A particularly useful tool for engineers is a bench-top test set that combines capabilities of the three major instrument types. The test set emulates an operating base station and other critical parts of the network to make real-world performance testing possible in the lab.
Control of the test environment