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EETE NOV 2014

M2M COMUNICATIO NS NFC and IoT: a marriage of cost-effectiveness and security By Alessandro Vigano Credit for inventing the phrase ‘Internet of Things’, now commonly abbreviated to ‘IoT’, is usually given to Kevin Ashton, a British engineer working at the Auto-ID Center at MIT, Boston, USA. Perhaps surprisingly, its origins go right back to 1999 but it’s only in the last two or three years that the electronics industry has become very, very excited about the possibilities that are emerging from the IoT opportunity. It’s not hard to see why. Since the Internet really got going a few years ago, around one billion premises have connected to it, so have around 5 billion people. But, depending on which forecaster you believe, it’s likely that by 2020, there will be 50 billion ‘Things’ connected to the Internet, many of them sending data to vast ‘cloud’ servers that will use it for monitoring, control and analysis. So what are these ‘Things’? They’re cars, domestic appliances, industrial machines, TVs, set-top boxes, and perhaps even LED lamps that you can switch on-and-off from anywhere in the world where there’s an Internet connection. But what really adds spice to the IoT market is the idea of portable devices being connected to the Internet, including wearable products. ‘Wearables’ will include medical devices and health and fitness gadgets - Things that can measure your pulse, blood pressure and more, then send that data, via the Internet to where it can be used. Which brings me to one of the biggest challenges of the promised IoT revolution, security. If your IoT ‘Thing’ is going to be transmitting your medical data, you may be choosy about how widely you share that information. If it’s being used to make a secure payment from your bank account, you may be equally sensitive about who gets to see your log-in credentials. Connecting things to the Internet Because the definition of ‘Things’ is so diverse, the ways in which they are connected to the Internet will vary widely too. Currently, fixed connections are usually made over copper cables and optical fibres, or a combination of both. If the ubiquitous smartphone is employed as a hub for the ‘Thing’, you’ll usually need a wireless link to get the devices talking to each other. For some applications, the wireless link will use technologies that are now built into almost every smartphone, WiFi or Bluetooth. But both of these have their limitations. WiFi is particularly energy-hungry, limiting battery life in portable electronic products. It broadcasts a 2.4 GHz or 5 GHz signal regardless of intent and there have been numerous reported incidents of hackers being able to intercept WiFi transmissions and extract the data embedded within them. Bluetooth also operates at 2.4GHz but over a shorter range and with reduced data rate. Bluetooth Smart, a relatively recent low-energy version of the technology, has reduced typical power consumption from around 1W for Classic Bluetooth down to 0.01 W. Maximum transmitted power is 10mW and the bit rate is 1Mbit/s. Latency and data transfer time have also been cut more than 10-fold from the earlier standard, further extending battery life in portable devices. And according to Bluetooth SIG (Special Interest Group), over 90 percent of Bluetooth-enabled smartphones will support Bluetooth Smart by 2018, so at first sight, it seems like the obvious candidate for linking a ‘Thing’ to your phone, from where the cellular network will provide the Internet connection. However, there’s another wireless technology beginning to take off after several years of promising benefits that have taken a while to be realised. It’s Near Field Communications, or NFC. And it’s very different from WiFi or Bluetooth in a number of ways that could make it attractive for many IoT applications. What’s more, it’s already embedded into more than 500,000.000 smartphones and tablets, with that figure expected to grow to 1.5 billion by 2017, according to ABI, the market analyst. NFC is different because it’s very short range, very private and secure, very low power and very low cost compared with the alternatives. It pairs and exchanges data between devices over a distance of only about 10cm, making it difficult for the signal to be intercepted. NFC devices don’t broadcast. Instead they require the application of an NFC device to an NFC-enabled object to read its memory. Other features of the protocol reinforce this inherently secure method of communication. Another key feature is that an NFC transponder, or tag, can harvest energy from the radio frequency (RF) energy emitted by the nearby NFC reader. This means that the tag doesn’t need a battery or power connection, keeping complexity, cost and size well below that of WiFi or Bluetooth approaches. NFC communication modes NFC’s communication modes are Read/Write, Peer-to-Peer and Card Emulation. In Read/Write, the NFC reader/writer, or NFC-enabled smartphone configured as a contactless reader/ writer, reads data from NFC-enabled smart objects which then responds with requested information in some way. For example, you might connect automatically to websites using a retrieved URL, send SMS messages without typing, or perhaps obtain discount coupons, with the near-touch of your phone to an NFC smart object. Alessandro Vigano is Business Development Manager at Linking an embedded system to the Internet using NFC. SILICA – www.silica.com 24 Electronic Engineering Times Europe November 2014 www.electronics-eetimes.com


EETE NOV 2014
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