The Bluetooth SIG put out a press release the other day saying that by mid-2009 a specification that includes Wi-Fi as an “alternate MAC/PHY” will be released.
This is the relevant part of the release:
What we’re doing is taking classic Bluetooth connections – using Bluetooth protocols, profiles, security and other architectural elements – and allowing it to jump on top of the already present 802.11 radio, when necessary, to send bulky entertainment data, faster. When the speed of 802.11 is overkill, the connection returns to normal operation on a Bluetooth radio for optimal power management and performance.
So this innovation specifies an interface above the Bluetooth MAC layer that enables Bluetooth session data to flow through a Wi-Fi radio instead of a Bluetooth one.
The press release says that the Alternate MAC/PHY will be used to do things like:
Wirelessly bulk synchronize music libraries between PC and MP3 player.
Bulk download photos to a printer or PC.
Send video files from camera or phone to computer or television.
But the new specification will only be useful in devices that already have both Wi-Fi and Bluetooth, and Wi-Fi can do these things without any assistance from Bluetooth. So the increment in value may be small; but Bluetooth can still bring something to the table. According to Wikipedia,
The Bluetooth Radio will still be used for device discovery, initial connection and profile configuration, however when lots of data needs to be sent, the high speed alternate MAC PHY’s will be used to transport the data.
It seems oddly limiting not to go the whole way, and enable Bluetooth applications to run on top of Wi-Fi even when there is no Bluetooth radio.
George Ou of ZDNet reports that the 802.1X authentication techniques used on some Wi-Fi handsets may be vulnerable. The problem is that these handsets may not validate the certificate from the authentication server. This design choice speeds up roaming, but means that the handset could disclose user login credentials to a sophisticated, determined attacker. Ou suggests using WPA-PSK with a long password instead of 802.1X with these handsets.
Vocera’s documentation, which Ou references, has more depth on the performance trade-offs of various Wi-Fi security options.
Owners of iPhones know that web browsing on the iPhone is a completely different animal than on any other cell phone. How different? Well, it would appear to be thirty to fifty times different.
Thirty times is difference in data usage between iPhone users and others on the T-Mobile network in Germany, according to Unstrung.
Fifty times is the difference in the number of Google searches by iPhone users compared to others according to Google.
Redpine Signals has announced that it is sampling a low power 802.11n chip suitable for cell phones. A reference design was certified in January, making it the first handset-grade 802.11n chip to market.
One of the major benefits of 802.11n is MIMO, so you might think that since a handset is unlikely to have multiple antennas, 802.11n isn’t going to help much. Actually, it will make an enormous difference in reliability and range, and consequently throughput. I wrote before about the array of improvements incorporated in 11n. The one of greatest interest in this context is Space-Time Block Coding (STBC).
The WFA website shows 90 Access Points (APs) certified for 802.11n, but STBC is optional in 11n, not mandatory, and not all the AP chipsets support it. The main makers of AP chipsets are Atheros, Broadcom and Marvell. None of these have mentioned STBC until recently. But now Broadcom says it is in the BCM4322, which is set to ship in the first quarter of 2008, and Marvell says it is in the TopDog 11n-450, which is scheduled to ship in 2Q 2008.
This Techworld article has a good discussion of the current state of enterprise 11n access points, noting that multi-radio APs are currently too power-hungry to be powered over Ethernet (PoE).
In May 2007 I showed a chart of dual-mode phone certifications by time. Certifications have continued to grow since then, as the updated graph below shows. These numbers are pretty raw, for example six certifications in November 2006 were for variations on a Motorola phone first certified in October. If you go back and look at the previous chart you will also notice discrepancies in the number of certifications for any particular month. These are presumably because of revisions at the WFA website.
From 2006 to 2007 smartphone certifications were essentially flat, going from 33 to 36, while feature phone certifications went from 11 to 21. These add up to 44 dual mode phone certifications in 2006 and 57 in 2007.