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Why Bluetooth version 2 matters
Faster data, lower power, more devices
By Peter Judge, Techworld | Techworld
Published: 17:00 GMT, 15 February 05
Bluetooth works just fine, but one of the least attractive things about it is its speed. When W-Fi networks start around 5Mbit/s, Bluetooth's sedate 700 kbit/s speed can feel limiting, when you are performing a task like synching a smartphone to your PC.
The emerging new version of Bluetooth will change that, by boosting the speed to 3 Mbit/s. but that may not be the most important addition, according to Anders Edlund, marketing director of the Bluetooth Special Interest Group (SIG) - who we last spoke to more than a year ago.
"Bluetooth 2.0 also reduces the power consumption by about half," said Edlund. He also promises that newer Bluetooth devices will make it easier to run several applications at the same time.
The speed improvement is real however: "It goes up from a maximum of 771 kbit/s to 2.1 Mbit/s, with a gross data rate of 3 Mbit/s. This is still only about half the speed of traditional 802.11b Wi-Fi, but nevertheless, more of a serious speed.
The lag from spec to product
The Bluetooth v.2 specification was published in 2004, but products are only just appearing - with Apple the first to include it in a computer - its most recent PowerBooks.
"Bluetooth was criticised for the four year gap between the first specification, published in 1998 and the first products," said Edlund. "That lag is much shorter now." However, even PowerBook users won't be able to get any benefit from Bluetooth 2.0 until there are peripherals that use it. "Other computers and peripherals will appear in the first quarter," said Edlund - until then, they can at least console themselves that Bluetooth 2.0 is fully compatible with earlier versions.
He expects to see version 2 on mobile phones by next year, but is less sure of delivery dates as handset makers' schedules are unpredictable: "Handset manufacturers are reluctant to give public information, because switching to a new platform is a big upgrade."
Phones will be the driving technology for version 2, as they ship in big volumes. Edlund pointed out that phones have already made the jump from version 1 to version 1.2 - albeit a smaller jump, and one that could be achieved by a software upgrade. "Version 2 requires a new radio," he admitted.
However, the benefits in phones should be impressive. "With phones getting more content rich, and memory sizes going up, users will want higher speeds to send image files," he said.
"With power consumption, roughly reduced by half, headsets will have a longer standby time, with the same voice quality."
New applications
With better power management and higher quality, Bluetooth may appear in new applications. So far it has rarely been used for stereo headsets, but they could become commonplace.
Doing more than one thing at a time will be a boon, he said. "You will be able to synch your phone, listen to music. and use a Bluetooth mouse and keyboard," he said. Previously the other activities would impact sound quality. For more on the nuts and bolts of Bluetooth read our other Bluetooth coverage.
Bluetooth versus Wi-Fi
With high volumes going into phones, Bluetooth is still a cheaper proposition than Wi-Fi: "The manufacturing cost is roughly a third that of Wi-Fi," said Edlund. The fact that it uses frequency hopping, means it is less limited in the channels it can provide without overlapping with other devices, he said.
Even commentators in the US, which tends to be more aware of Wi-Fi than Bluetooth, are saying that Bluetooth is a better fit than Wi-Fi for the needs of a mobile phone.
What next?
The Bluetooth SIG plans to have a new update every year, with the next one coming at the end of 2005. However, this is most likely to be a point release, that can be managed by a software upgrade: "We don't want to make people change hardware every year," he said.
The main features that will be added to Bluetooth over time are
- Further power optimisation
- Security enhancements (though Edlund stresses that security fears are overstated and this is not a major change)
- Quality of service, intended to make it easier to use multiple applications.
What about ultra wide-band?
With Ultra Wide Band proposed as a replacement for USB connections, Bluetooth people are looking over their shoulder.
"It is a promising technology," said Edlund. "It is an interesting question whether Bluetooth will run over UWB, or hand over to it. The two could be a very good complement."
However, he is definite that UWB will not wipe Bluetooth out, if for no other reason than power consumption, in applications that don't need the high data rates promised by UWB. "Even though power consumption per bit is good in UWB, overall power consumption is not so good," he says.
Also, UWB will not be commercial for some time he said, especially when you consider the regulatory hurdles, which strike UWB's radical transmission method particularly hard. "Bluetooth has been working with regulatory issues for seven years now," he said, and even that is not really 100 percent accepted.
And how about Zigbee?
At the opposite end of the scale, Bluetooth could soon be facing rivalry from the low-speed, low-power Zigbee technology. Intended for sensors, Zigbee is designed to go slow, and conserve battery life, so it can be used in sensors that must remain active for up to several years.
"There might be increasing overlap in this area," said Edlund. Already Bluetooth is being used in disposable sensors, and future developments will make it even more suitable. "In 2005 we will further reduce power consumption, and in 2006 we will improve range without sacrificing power consumption, and make it possible to have many more sensors connected at the same time," he promised.
"Zigbee has three different flavours, which will cause fragmentation," said Edlund. "Its biggest advantage is a very much lower data rate and slightly lower power consumption." It would be some years before Zigbee could build volumes that would threaten Bluetooth, he predicted.
Conclusion: the future is blue
Edlund's optimism is unbounded, with his assertion that
- Bluetooth is unassailed in a large niche that ensures volumes that can keep its price down.
- Its technology is changing fast enough to meet increasing demands, and
- Its rivals are aimed at complementary niches, where they will not threaten Bluetooth
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