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TEST & MEASUREMENT Although the additional level of testing required for IoT may seem to be a burden that is difficult to support, research into software costs has shown that this attention to detail can pay off commercially. In a seminal paper published in IEEE Computer in 2001, Barry Boehm and Victor Basili of the University of Southern California and the University of Maryland, respectively, found that it costs 50 per cent more per source instruction to develop high-dependability software products than to develop low-dependability software products. But, using the Cocomo II maintenance model, they found low-dependability software costs about 50 per cent per instruction more to maintain than to develop. High-dependability software on the other hand costs 15 per cent less to maintain than to develop. Making IoT systems more resistant to problematic external code and events – and thus avoiding inconvenient reflashing of the device – is likely lead to much lower maintenance costs than for systems where those precautions have not been taken. The IoT will do much to increase the level of automated intelligence around us. It will also, because of this, change the way embedded systems developers handle validation and verification. Wideband systems for RF signal capture and analysis By Rainer Perthold Radio signals are all around us. With so many transmitters, both satellite and ground-based, there’s a growing need for monitoring. There are many applications that require the capture and analysis of radio signals. Government bodies may need to review signals to check compliance with the appropriate regulations, or to assess any problems with interference. For example, in the UK, Ofcom acts as the independent regulator for the communications industry, and in Germany the Bundesnetzagentur ensures compliance with the country’s telecommunications act. Another requirement is for COMINT (communications intelligence) and ELINT (electronic intelligence). This kind of work deals with intercepting and analysing communications, typically for surveillance or information-gathering. The signals captured can include a wide range of RF frequencies, whether they are from satellites or other sources. Depending on the application, a user may want to record the signals, analyse them in real time, or store them for offline processing. There is also a need to archive the captured signals for later reference. Typical radio monitoring applications require a flexible access scheme where all intercepted signals are buffered, while operators or automatic classification and analysis tools browse through the available content. Wider bandwidths needed While this kind of monitoring and analysis is a long-established application, there is a recent trend towards continuous surveillance of all signals across wider bandwidths. Instead of selectively monitoring individual transmissions, organisations want to run automatic signal collection and analysis, all the time. The objective of this continuous monitoring is to ensure that no relevant transmissions are missed. This puts additional demands on the equipment used, both in terms of the wider bandwidths targeted, and in the sheer quantity of data generated. Another driver towards wider bandwidths is cost reduction by minimising the number of RF receivers required. Traditionally, organisations might use many narrowband receivers to monitor a frequency band – possibly as many as several hundred, if needed. If a single device could capture signals across a much wider bandwidth, this would allow fewer receivers to be used, thus saving money. Finally, wider bandwidths are increasingly required simply due to the wide bandwidth of signals to be monitored. For example, global navigation satellite systems (GNSS), such as GPS and the European Galileo system, typically have signals across a wide bandwidth. GNSS satellites transmit navigation signals in the L band, which covers the 1 to 2 GHz portion of the radio spectrum – for instance, the GPS L1 band uses a centre frequency of 1575.42 MHz. The bandwidth of the signal itself can be measured in tens of MHz, which can cause problems for narrowband receivers – the best way to handle the full bandwidth is to use a wider band receiver. Hardware and software solutions To meet these needs for continuous monitoring and wide bandwidths, manufacturers are developing hardware and software solutions that provide the performance required. Let’s look at Rainer Perthold is the CEO of IZT Labs - www.izt-labs.de 28 Electronic Engineering Times Europe December 2014 www.electronics-eetimes.com


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