jeudi 17 novembre 2011

Instant mobile networking: Smartphones get smarter


November 11, 2011

Mobile devices packed with NFC, Wi-Fi Direct, and Bluetooth hint at what's coming in ad hoc communications


There's been a lot of excitement in some quarters around Google's decision to enable near-field communications (NFC) data-sharing in Android 4 "Ice Cream Sandwich." The news builds on Research in Motion's inclusion of NFC in its latest crop of BlackBerrys and Microsoft's announcement that it would add NFC APIs to its Windows Phone 7 smartphone OS in 2012.
You can add to that hubbub Apple's recent adoption of the Bluetooth 4 spec (aka Bluetooth Smart) in its iPhone 4S and the finalization a year ago of the Wi-Fi Direct standard. These three technologies allow direct connections among devices, eliminating the need for a router or other network for communication.
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Most of the early NFC buzz was around mobile payments, where a smartphone could communicate payment information to a point-of-sales (POS) terminal. But that technology is old news -- contactless payment cards have been around for years, though not widely used.
Plus, you don't really need two-way communication for such payments. Contactless payment technologies such as RFID serve the same purpose by presenting the user identity to the payment terminal, which then connects to the payment system over the network -- is exactly how debit cards and credit cards already work. RFID has been proposed for such usage for a decade, but that hasn't happened much either. Honestly, swiping a debit card is not a big deal, so the rationale for retooling the entire payment system is suspect.
But if you look beyond POS payments, something more interesting -- and useful -- is going on. That's the idea of ad hoc networks, where people can exchange information among one another and/or a collection of their own devices without an active Internet connection. Think iCloud without a network.
We've seen a variety of starts in such short-range connections. Remember the "bump to sync" apps for iOS that used the motion sensor to detect brief physical contact between two iPhones to allow business-card exchange? Or the touch-to-sync feature in some Palm smartphones and the Hewlett-Packard TouchPad that used a tangible touch to trigger sensors and initiate a transfer of information such as current URL or current email message from one device to another? NFC, Wi-Fi Direct, and Bluetooth get rid of the tactile kickoff.
Speaking of Bluetooth, why do we need anything else for ad hoc networking? Isn't that the whole point of the technology? It is, but several problems have restrainted Bluetooth's use. One limit is its dependence on profiles that all devices need to know about in order to connect. That becomes a nightmare for device makers to manage, and efforts by groups such as the Open Mobile Terminal Platform only partially address the issue.
Another limit is its need for explicit pairing, which usually takes several steps that users are unlikely to take for casual sharing, such as in an elevator or lobby. It's one thing to make the effort to pair your Bluetooth headset to your smartphone, as you'll use that pair repeatedly in the future, but quite another to do so in a meeting room with someone you just met and may never see again.
A third limit is that Bluetooth saps power fast. The new Bluetooth 4 spec addresses that, but chips are only now coming to the market, and the iPhone 4S is so far the only nonsensor device to use it. The new Bluetooth spec also speeds the data throughput, a limitation in previous versions that made it unsuitable for large file shares, screen sharing, or video streaming.
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http://www.infoworld.com/d/mobile-technology/instant-mobile-networking-smartphones-get-smarter-178661?source=IFWNLE_nlt_networking_2011-11-15

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