If Bluetooth were a creature, it would have fascinated Darwin. Throughout its history it has been threatened on all sides by other standards, and has managed to adapt itself to seize a slightly different opportunity each time, and achieve its huge installed base in phones, PCs, headsets and cars. But other technologies continue to steal its best ideas and limit its potential once more, with Wi-Fi the most persistent. First the 802.11 community created a group to look at a very low power version for Bluetooth heartlands like home control, then it came up with an ad hoc mode which emulates the slower standard’s most distinctive characteristic.
New research by In-Stat predicts that the new Wi-Fi Direct platform will cast serious doubts over Bluetooth 3.0, a high speed mode which, at one time, was seen as a possible thorn in Wi-Fi’s side. That was when High Speed Bluetooth was going to use an UltraWideBand physical layer, bringing it close to the WiMedia standard, which quit Wi-Fi’s home at the IEEE and eyed 802.11’s home networking territory.
But WiMedia failed and the Bluetooth SIG adopted a Wi-Fi foundation for its fast standard instead. Bluetooth 3.0 uses the usual version of the technology to connect to devices and Wi-Fi to deliver speeds of up to 24Mbps. To keep power low, conventional Bluetooth is used for many connections, with the Wi-Fi hybrid reserved for those needing faster speeds. But In-Stat principal analyst Brian O’Rourke believes the new peer-to-peer Wi-Fi Direct technology could ‘eliminate the need for Bluetooth 3.0 altogether’. He explained: ‘Standard Wi-Fi is increasingly common in many Bluetooth target markets. Until recently, lack of peer-to-peer connectivity was Wi-Fi’s most significant weakness in those markets.’
With Wi-Fi still having significant issues with battery life in phones, classic Bluetooth is likely to remain a component of mobile devices for a very long time to come, and there will be strong growth in USB adapters and game controllers. But the biggest growth market for Bluetooth chip suppliers may come from its other new iteration, Bluetooth Low Energy, rather than the fast version ‘ a prediction that also raises question marks over its next generation high speed development for 60GHz, where Wi-Fi also plays.
The Low Energy version targets industrial, medical and home automation sectors, all seeing high growth, and hits Wi-Fi where it still hurts, in power consumption. This Bluetooth capability is starting to appear in silicon. Along with the classic and high speed modes, it is part of the v4.0 release, which allows all three variations to be mixed and matched in the same devices. In future, the high speed option is likely to use a 60GHz technology, such as WiGig (another offshoot of Wi-Fi) or WirelessHD, as its transport layer.
As for Wi-Fi Direct, the Wi-Fi Alliance recently started certifying products for the standard, which supports peer-to-peer communications without the need for a hotspot or access point. This could lead to a dramatic change in how people communicate on the move, with the ability to link up and share files far more flexibly than now.
Wi-Fi Direct brings ad hoc connectivity, similar to that in Bluetooth, to WLans. Wi-Fi has had an ad hoc mode before, but this has been weak compared to Bluetooth’s, and never included in the main, certifiable Wi-Fi standard. Like most true ad hoc technologies, it has been weak in security and throughput. With the new system, one-button linking and WPA2 security are part of the standard, and provide the major improvements on the ad hoc mode enabled in previous Wi-Fi iterations, which could be clumsy and potentially insecure.
Direct, in effect, offers a halfway house, based on a software AP that mimics the functions of full infrastructure. It can also be seen and potentially shut down by enterprise APs, in order to be ‘enterprise acceptable’. Connecting with Wi-Fi Direct will require a device equipped with the new capability, but a Wi-Fi Direct gadget will be able to connect directly with older WLan products too, acting as an access point for them.