Filed under: Bluetooth, iPhone, iPod touch
Bluetooth: Another Wi-Fi killer for the iPhone?
More coverage of the ongoing Wi-Fi struggles of iPhone 3.0 users: In a discussion comment, Liam noted that he got full bars but no Internet using his iPhone 3GS until he turned off Bluetooth. After reading that, I wondered if Bluetooth is another suspect in the widening catalog of speed and signal problems reported with the iPhone 3GS and the iPhone 3G / iPod touch combination.
I ran the DSLReport speed test on my iPhone 3GS and found that with Wi-Fi and Bluetooth both enabled, latency increased a bit, and download speed decreased by over a third when compared to running the test with Bluetooth disabled. Upload speed didn't seem to be affected.
A possible reason was proposed by Doug Hogg of Toy Kite Software, creators of the Bluetooth-enabled two person game iSamurai: Real Life Sword Fight. Doug discovered problems in playing the game after updating to iPhone 3.0 software, but found that turning off either Bluetooth or Wi-Fi solved everything. It seems that both Bluetooth and Wi-Fi share the same antenna, so when Bluetooth was made active in the 3.0 software, conflicts arose.
On the Toy Kite Software site, Doug was a bit more specific. The iPhone 3.0 software brought with it a service discovery process that switches between looking for another device on Wi-Fi and Bluetooth using the single antenna. While searching, problems can occur with already established connections that can cause lags and loss of data packets sent between devices. Apple is working with Toy Kite Software to correct all this, but I wonder how much speed and even signal strength loss can be regained by turning off Bluetooth when it's not being used. In my case the difference was substantial.
It's also interesting to note that the iPhone 3GS uses a combination Wi-Fi / Bluetooth Broadcom chip that handles 802.11a/b/g as well as Bluetooth 2.1. Previously separate Wi-Fi and Bluetooth chips were used.
If you are having any speed or signal problems, try turning off Bluetooth and see what happens. I don't think that this will solve everything, but until Apple gets its act together on fixing all of this, what we're left with is a rag-tag assortment of tricks that may or may not help.
Let us know if this one works for you.
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Reader Comments (Page 1 of 3)
flanaganiii said 8:53PM on 7-15-2009
WiFi and Bluetooth share the same spectrum (2.4Ghz). And, because Bluetooth is frequency hopping, and isn't "listen before talk", it tends to do a lot of damage to WiFi.
Cisco is doing a lot of work in this area, to try to make WiFi more reliable. There are also a lot of other tools that can help track down this type of interference. Check out
http://www.cisco.com/en/US/products/ps9393/index.html
or Metageek for a cheap version of the product. http://www.metageek.net
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Greenie said 9:08PM on 7-15-2009
Sort of on topic: any thoughts on why 802.11n wasn't included on the 3GS? More expensive chip?battery hog? Or maybe just something they're holding out on fir the next big upgrade?
I don't know enough about hardware to give an educated guess.
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Kevlar said 10:10PM on 7-15-2009
If I would venture a guess: slightly more expensive chip, greater power requirements, and the number of consumers who would benefit from it is extremely small.
Note that I said BENEFIT, not the number of consumers that have 802.11n.
Of the two major advantages to 802.11n, faster speeds and greater range, only the range boost would be of any use to someone, since the speeds will be limited to your internet connection anyways (can't think of any use for an iPhone to stream HD video or large files over the LAN).
Even with greater range, you'd have to have a pretty big house, or routinely use WiFi a block away to make it worthwhile.
Jus' my figurin'.
Greenie said 11:48PM on 7-15-2009
Kevlar, good points.
I think there would be one big benefit for a lot of people in that their home network would be N only. This way, I don't have to have my iPhone slowing down the network to 802.11G when my Apple TV is trying to sync videos from my Mac.
jacjustjac said 8:37AM on 7-16-2009
That's what dual band routers like the Airport Extreme are for. They let your iPod touch work at G speeds on a separate network, without slowing down your 802.11n devices.
Greenie said 10:17AM on 7-16-2009
jacjustjac, I'm familiar with these routers. But, I have a perfectly good router at home already.
Nate said 9:13PM on 7-15-2009
Wow... Bluetooth cut my download in half and doubled my latency:
Wifi w/o Bluetooth - Lat: 154 ms. Down: 11015 kb. Up: 2495 kb.
Wifi with Bluetooth - Lat: 296 ms. Down: 6573 kb. Up: 2186 kb.
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David Winograd said 3:20PM on 7-16-2009
When Apple announced that 802.11n would not be in the iPhone 3GS I was really disappointed since that was one feature I really wanted.
I've heard a lot of people saying that the phone isn't fast enough for draft n and although the chipset is there, the battery demands are just too high.
Well batteries aside, I want draft n so I don't have to cripple my draft n network with slower speeds and I'm not going to buy new dual band equipment. Shoot, I just went to draft n a few weeks ago using a first gen time capsule and 7 airport expresses.
Forgetting the iPhone speed problems, I'm now concerned with slower network problems.
I brought this up a few times in the past and it gained no traction with some saying that the iPhone will never get draft n since it doesn't need it.
Well I think it does!
andreoutlaw said 4:55PM on 7-16-2009
@david
I had the same issue. I just bought a N router to serve HD video to different points in the house. I found if I used both G and N my bandwidth was crap. But with only N running everything worked great.
I just used my old router on one of the ethernet bridges that was receiving my N signal. So everything that I have that only goes up to G can connect to that router and everything that can use N can connect to the new router.
mxtrader said 9:40PM on 7-15-2009
Oh how sad.
I used to have a very old iPaq and never heard of this problem of sharing the same frequency...
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spedione said 9:21PM on 7-15-2009
I had the same issue using the 3.0 Beta, where WiFi was slow to the point of being unusable. I just stopped using Bluetooth.
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BeyondtheTech said 9:30PM on 7-15-2009
I'm wondering about the omission of 802.11n, also. Betcha they'll have it in July 2010 with a front-facing videoconferencing camera and call it the iPhone 3GS Pro.
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Hi Kenneth said 9:47PM on 7-15-2009
this would explain why my iPod Touch's internet apps slow down or wont work...
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flanaganiii said 9:49PM on 7-15-2009
802.11n requires more power. Actually a LOT more power. I'm sure they will have it, but the real advantage of a "pro" won't be that.. it will be that they've upped the battery to make the thing actually work well with 802.11n for a reasonable period of time.
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Mike said 9:51PM on 7-15-2009
since buying the 3GS I've noticed the bluetooth acts strange in my car. I have an Audi with bluetooth integration. The phone is supposed to pair with the car when I turn on the ignition. It does, but then it drops it a few seconds later, then a minute later it recognizes it again. So something's going on with the bluetooth for sure.
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Scott said 10:24AM on 7-16-2009
I'm having the same problem, except that it only happens ~1/2 the times I start the car. Never had problems with my 1st gen iPhone. WiFi signal strength is also well down from what I was used to with the 1st gen.
Probably unrelated, but my cell signal strength is also all over the place. Sitting at my desk at work I get everything from 5 bars with 3G to 1 bar with Edge to "No Service". Very frustrating...
Bryan said 10:18PM on 7-15-2009
I had noticed throughout the 3.0 betas that when I had wifi on that my bluetooth stereo sound was pitiful. I had bought a nice set of headphones and thought I had blown the speakers...
Turn off wifi, awesome sound. Still no FF or RW, but it does work.
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Kevlar said 10:15PM on 7-15-2009
I'm having this issue too! I returned the headphones, thinking they were blown, and tried out two other models/brands, with no luck.
I thought I was going to have to live with the annoying static!
Please, tell me exactly what you did to fix it!
Kevlar said 10:19PM on 7-15-2009
I just tried it with the WiFi off, with no luck. I even turned every freaking radio the iPhone has off, and then re-paired the heaphones. The static is still prominent on every vocal "sss" or cymbal or snare.
I have a black, 16GB iPhone 3G, and this issue is really starting to drive me nuts!
kohrtoons said 10:07AM on 7-16-2009
I think that has more to do with the headphones themselves, a true audiophile would not use bluetooth headphones as they are not the same quality of standard headphones.