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EETE JULAUG 2014

executive interview 5G, IoT pose new challenges to testing By Christoph Hammerschmidt With test automation being a burning issue, 5G radio networks in the transition from the embryonic to the fetal phase and the Internet of Things taking shape, manufacturers of test equipment are active in a terrain mined with technology decisions that need to be taken but many uncertainties as to which direction the markets will develop. EE Times Europe discussed these issues with Jonathan Borrill, Director of Market Strategy at RF test technology provider Anritsu EE Times Europe: Which are currently the hottest technology trends in RF for your business? Jonathan Borrill: There are two important trends. In the mobile phone communications business we see that handsets and networks are having more and more radio bands. This raises the requirements to RF technology and components in terms of bandwidth, efficiency, multiband designs, antennas, multiband amplifiers - you name it. In this context, the use of MIMO is going to spread - all LTE handsets today are using MIMO, and we think that about 70% of all new smartphones are LTE-enabled. These handsets transmit and receive in some 14, 15 different radio bands - plus Bluetooth, Wi-Fi, FM radio and NFC. This leads to very complex RF designs in a handset. We have to test all the bands and their combinations and which is the real challenge - the interferences between the different bands. Testing each band individually is a very straightforward approach; it is the interactions between the different bands that make the whole thing complex. Another challenge is the testing efforts. For the design engineer this can “For mobile phones, in GSM, 3G and Wideband CDMA Europe really led the world in the technology. In LTE Europe lost this leading position.” mean weeks of testing - he needs to know with effects like intermodulation between adjacent frequency bands and similar things come into effect. Testing up to 14 frequency bands plus their interaction takes more time than just testing 14 frequency bands. And yes, there are physical limits - it takes a certain time to sweep across the spectrum. But our customers can’t afford to increase the testing time so much. It has to be faster, cheaper. Nevertheless, it can take maybe two weeks to put a handset through the entire certification. EE Times Europe: Two weeks for every single mobile phone? Borrill: No, this refers to the design testing. On the production line it is different. There you only test the actual manufacturing process. On the production line the test takes 20 seconds. EE Times Europe: How does the emerging Internet of Things (IoT) wave affect testing and measuring? Borrill: One part of the IoT is the concept of having wireless communication modules in everything. To connect to the Internet, one needs an RF module in every device at really low cost. The challenge we have then is to enable also testing at low cost - but imagine the huge volume of testing. So on one side, the volume of test - which means the cost of test - goes up and up, but there is a need to bring the cost down. So the challenge is to keep the test good enough and keeping the price adequate for low cost modules. EE Times Europe: These considerations seriously limit the price for test equipment? After all, there are billions of IoT nodes to be tested. Borrill: It is not a limitation but a challenge for us. The pressure is on to bring the cost of test down. EE Times Europe: Is test automation something that helps to reduce these costs? Borrill: Absolutely. Today, for communications devices we can fully automate the test process. But it is still the sheer volume of testing. We do apply smart algorithms to schedule testing - the sequence in which you do the tests can affect the test time. There is actually a major technology change in the work with the designers of the chipsets. For instance, if you test a handset and you want to see if you can make a call, you set up the call, you make your measurement and then release the call. This all takes time. We have examples where the test itself runs for tens of milliseconds but it takes ten seconds to put the mobile phone in the right condition to get those milliseconds of data. So there are new algorithms where we can talk directly to the chipset and tell it to just transmit what we need. Thus, those ten seconds of setup time can be reduced to milliseconds of setup time - which makes a massive improvement in test time. Thus, you can cut down a mobile phone production test from three minutes down to 20, 30 seconds. EE Times Europe: Is 5G communications technology already something that affects your developments? Borrill: We are starting to see the first requirements and basic technical directions of 5G. We see that millimetre wave backhaul is requiring more advanced high-performance testing, we expect wider bandwidth modulation schemes, wider bandwidth for signal generators or for signal analysers. EE Times Europe: are there different modulation schemes compared to current-generation mobiles? 18 Electronic Engineering Times Europe July/August 2014 www.electronics-eetimes.com


EETE JULAUG 2014
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