Bluetooth--How Fast Is It?

Apple is once again pushing the computing envelope by implementing a cutting-edge technology. Bluetooth is the common name for a recently introduced low power wireless data transfer protocol. It connects up to a distance of about 33 feet (10 meters). Bluetooth is designed to wirelessly connect peripherals to computers and among computers.

Apple's CEO Steve Jobs introduced Apple's implementation of Bluetooth in his keynote address at Macworld 2002 Tokyo last month and demoed it by wirelessly synching a Palm PDA to a Mac. At the same time, Apple released Apple Bluetooth Technology Preview 1.0 software on its Bluetooth web page and began selling D-Link DWB-120M Bluetooth USB Adapters (transmitter/receiver modules) for the Macintosh on the Apple Store for $49. We were on travel at the time and thought we might be able to pick up the D-Link modules at the Apple Store in Tyson's Corner, VA, when we returned. We checked Saturday but they didn't have any. Since they weren't certain when or if they might get some for demo or sale, we ordered two off the online Apple Store--they arrived Wednesday and we got a chance to check them out yesterday.

In the interim, we found that Bluetooth devices are still relatively hard to find. We don't have/use a Palm PDA that is Bluetooth capable nor do we have a Bluetooth capable cell phone. Bluetooth cell phones are rarer than blue hens teeth (sorry for the pun) but we're hot on the trail of a Sony Ericsson T68i. [Update: Powerpage has an excellent article on the T68i.] We discovered that among all the cell phone digital services only VoiceStream admits that the T68i will work on their service if and when we find one in the US. [Update: We found one!] Cingular and ATT thought they *might* work since their service uses TDMA technology like the T68i but we got conflicting advice when we called around. [Update: From Ron Postma, "I own a wireless company in Portland Oregon. We sell AT&T, Nextel, and Verizon. I have recently tested a AT&T T68i with my G3 PowerBook 2K and it worked very well. I connected to the internet and received download speeds between 28k bps to 48kbps. I used a T68i modem driver found on this URL <http://www.taniwha.org.uk/>. I have also tested it on a PowerBook G4 both laptops were running Mac OS X."] Sprint and Verizon use CDMA technology and we could not find a Bluetooth phone that uses CDMA. Nokia is likely to have a CDMA Bluetooth phone available in the US in the near future.

Bluetooth also provides a wireless connection between two Macs so we downloaded and installed Apple's software on our G4 Cube and iMac DV SE, both running Mac OS X 10.1.3 which is required. We plugged one of the D-Link modules into a USB port on our iMac's keyboard and the other into our Cube's keyboard. A small green LED glows to show it's live. Pretty simple.

Apple provides a PDF file which explains how to set up the Bluetooth preferences panel, synch with a PDA, connect with a cell phone, connect to the internet via the cell phone (our principal interest) and connect two computers to share files. It all looks pretty simple but we were only able to try the inter-computer file transfer capability.

Transferring files is very simple. Just drag and drop the file on the Bluetooth File Exchange application installed in an "Extras" folder in the Mac OS X Applications folder. A dialog box comes up and quickly lists the Bluetooth devices in range. Just select the device you want and click send.

So how fast is Bluetooth? We ran a test by copying two files from our iMac to our Cube using Bluetooth and AirPort, Apple's WiFi wireless networking device. The computers are about 22 feet apart, two thirds of the Bluetooth's maximum range and are in separate rooms, a pretty severe test. The two test files were the 19.7 MB iMovie for X v2.1.1 application and the 9.1 MB Mac OS X Server Admin Guide PDF. Mac OS X applications are really folders of several to many files. We recorded the time it took from when we clicked "Send" in Bluetooth and from when we dropped the file in AirPort until the transfer was complete. Here are the results in seconds:

Time to Transfer File (seconds) at 22 feet

File/Size	Bluetooth	AirPort
PDF/9.1 MB	317	21
iMovie/19.7 MB	652	206

The Bluetooth application showed that the transfer rate was 27-32 KB/sec for both files. This range is consistent with our measurements. With AirPort, however, the transfer rate was much faster with the PDF (433 KB/sec) because it is a single file while iMovie (96 KB/sec) is really a folder of many files. Both AirPort transfers are much faster than Bluetooth as expected. It is possible that our Airport interfered some with Bluetooth but it is 10 feet (3 meters) away.

We then installed Bluetooth on our PowerBook G4, placed it 3 feet from our Cube and transferred the two files with AirPort off. We turned AirPort back on and transferred the files again. Here are the results:

Time to Transfer File (seconds) at 3 feet

File/Size	Bluetooth	AirPort
PDF/9.1 MB	150	18
iMovie/19.7 MB	321	189

A rate of 60-62 KB/sec was shown by the Bluetooth application, a little over twice the rate at 22 feet. AirPort was only about 8-10 per cent faster.

Bluetooth wireless file transfers for small files at close range are not unreasonably slow but are much slower than by AirPort. Two Bluetooth modules cost $98, slightly less than half the price of two AirPort cards, and work on any Mac with a USB port that will run Mac OS X 10.1.3. However, Bluetooth will really come into its own when it becomes more commonly enabled in a wide range of peripherals. Apple does it again, folks!