I have an iPhone 3G, and lately I’ve been saying that it’s the best gadget I’ve ever owned, and the worst phone I’ve ever owned. There’s been two main reasons why, one of which Tony helped fix a few days ago. Allow me to tell you a story.
Firstly, ever since I installed the iPhone SDK (software development kit; the tools necessary to build applications for the iPhone) I started getting an error everytime I tried to sync the device. Tony pointed out that leaving tethering enabled caused issues, and disabling it on the iPhone has meant this probem went away. I think it was just a co-incidence that I’d installed the SDK, but it might not have been; it didn’t cause that error previously when tethering was enabled.
More importantly though, in the last few months I’ve had more dropped calls, failed calls and general frustrations with the iPhone than I’ve ever had with any phone, ever before. There’s a specific section of Berwick Street that, without fail, will disconnect any calls as I drive through it. My tech-mind put that down to the phone jumping from one cell tower to another, and that made sense. Then the calls started to fail anytime I’d attempt to make them. Then they’d start dropping with a “call failed” error when people called me. Not to mention that the mic stopped working for a while, and I’d have to switch to speaker mode to talk to anyone, though I think that’s more to do with crap getting in the headphone jack (which I use all the time in the car, for music and podcasts) and it thinking that an audio cable is attached.
As you can imagine, this is all quite frustrating, considering how important my phone is for work, let alone socially. There’s little relief in the knowledge that it’s fairly well accepted that 3G on the iPhone uhh 3G isn’t all it’s cracked up to me. The problem is, who’s to blame - the carrier (in this case Vodafone Australia), Apple, or Infineon, the 3G chipset manufacturer?
My short-term solution has been to disable the 3G network, and stick to WIFI when I’m at home or in the office, and regular ol’ 1G (or is it 2G, or 2.5G, or 3.14G?) when I’m making calls. That works kinda OK, but it’s annoying having to go into the settings to enable 3G anytime I check Twitter at a cafe, for example. I know, it’s such a first-world-problem, isn’t it?
Earlier this morning I found out that the iPhone supports a field test mode, which you can access by dialing:
*3001#12345#*<call>
Don’t forget that last star - I was missing it off and getting a “Error performing request No Network Service” message popping up.
There’s a whole raft of information that’s available here, but the only bit that interests me is the signal strength indicator that appears in the top left corner, where the “bars” normally are. This turns into a negative integer, where the higher the number (closer to zero) the better the signal. For the mathematically-challenged, this means -60 is better than -80. According to TestFreaks (when they tested the Cell Ranger Port, an interesting signal amplifier):
| Signal Range |
Result |
| -80 to -70 dBm |
Reasonably strong signal |
| -107 to -90 dBm |
Weak signal |
| -113 dBm |
No servicable signal |
For me, sitting at my desk in West Perth I get -81, which shows up as 5 bars. To be fair, the downstairs office is three walls of concrete, with three storeys of concrete above above, and a wrought iron clad window. It’s pretty much impervious to radio frequency signals. If I cover the antenna area (which is at the base of the handset, incidentally right where people tend to hold their phone) then the signal drops to -95, which is a significant change. I figured I’d check out the reception on Wellington Street, where to my surprise I get a solid -57.
OK… now we’re getting somewhere.
Further investigation also revealed an CNet article which suggests that you can boost the signal by attaching a piece of sticky-tape to the backside your SIM - it’s got something to do with the SIM making firmer contact with the phone. They also recommend using an eraser to remove any oxidation that might have ended up on the SIM. It’s all about the contacts, baby!
And then it hit me - a few weeks ago my phone reported that it had no SIM! I rebooted the phone and it worked fine, so I had just dismissed it as the phone being silly. Maybe there was a connection issue that was causing problems?
I dug out some scotch tape and found a paperclip on Hale’s desk, and went to work. I stuck two pieces of tape to the back of the SIM, just to be sure. I cleaned off the oxidation with an eraser. This changed resulted in -81 inside, -51 on Wellington Street, so no change inside, but a jump of 6 points outside. That’s not bad, but might just be a regular fluctuation.
As a last test, I checked the inside strength again. I saw the inside value change from -73 (momentarily) to -79, and then hover around -75. Then back up to -81.
The end result: I’m not sure that the hackery did much, in fact I don’t think it changed anything to be honest. I think what’s more likely is that Vodafone are being a little generous with their “convert signal reading to bars” function, and should be showing me less bars when I have a poorer signal.
Either way, I’m now armed with a snugly-seated-deoxidised SIM, and the tools to measure signal strength next time I get a drop out. I’ll keep you updated.