Post image by OrbitalJoe

It’s been interesting to read the conversation around the post I wrote in October about iPhones using excessive amounts of cellular data.

For some people it’s a case of not realising they were on cellular while downloading apps. For some the data use seems to be happening at night, when the phone would be on standby and, annoyingly, not connected to WiFi. Another suggested cause is the iPhone sending diagnostic data to Apple, with the associated solution of turning that off.

Zoe, the friend who originally brought the high data usage to my attention, has posted about the steps she’s taken to reduce data use and the effect it’s had. I won’t reproduce her entire article, but a combination of careful app choice, closing them manually after use, and changing e-mail settings has drastically reduced her data use.

Have you experienced high data use on the iPhone? Have you taken steps to reduce it? Perhaps with some of the suggestions from this site or Zoe’s? If you’ve found a way to cut your data down to size, we’d love to hear about it in the comments.

Post image by OrbitalJoe

When UK iPhone carriers announced that they would be doing away with unlimited data plans I had a minor panic. I’m on unlimited broadband at home and it’s always a comfort to know that whatever I do online I won’t hit a download limit. If there was to be a limit on my iPhone use wouldn’t there be a chance I’d end up hitting it?

Well, when I checked my monthly usage it was only about 300mb – well under the 500mb minimum level set by my provider (O2). So I wasn’t worried. However, several of my friends and other people from around the Internet are reporting hugely increased data usage on their IOS4 iPhones… that’s iPhone 3GSs running v4+ of the iPhone OS, or the iPhone 4 itself. How big is the increase? Well, as an example, Zoe reports somehow using 450mb in just six days. That comes out at 2.25gb in a month! What’s going on?

I decided to track my data use for a few days by downloading DataMan from the app store. My results are by no means conclusive, but I hope you’ll find them useful.

Location services?

The iPhone’s location services uses a few different methods to work out where you are. There’s GPS, triangulation via mobile masts, and checking any nearby wifi networks against a database of their locations. If you have an app running that uses location services (you’ll see an arrow at the top of your screen) there will most likely be some data use. But 75mb in a day? I don’t think so – there’s no way that amount of information is required just to tell where you are. To test this I went out on a long walk with Runkeeper Pro running… which tracks where I am, maps it for me, and even lets me upload photos I’ve taken while out and about. I uploaded a photo just to make sure I was using everything properly, and I should mention that DataMan also requires location services to be switched on.

Result? 1mb of cellular data was used. It doesn’t look to me like location services is the culprit. However, if you are really concerned about data use, or just worried that your iPhone might be spying on you, you can switch location services off in the General tab of the Settings screen.

Multitasking?

One suggestion is that it’s the new multi-tasking ability that’s eating into data: apps running in the background that are continuing to send and receive data. This is certainly possible – I often minimise apps and want them to keep doing whatever they’re doing – but unless you specifically close them those apps will remain in the background even when you’re finished with them… days at a time. If this is a concern to you (and it is to me, but usually because I think having too many active apps will slow my phone down) double-tap the home button on your iPhone, then hold your finger on any of the active app icons. They’ll start to “jiggle” and a red X will appear on each icon. Tap the X and the app will be properly closed down.

I strongly suspect that background apps are the main culprit for excessive data use and would recommend manually shutting anything down that you’re not using. It’s just a shame that the method for doing so is a bit fiddly.

But I’m on WiFi! Why am I using cellular data?

Yep, I wondered how I had managed to use cellular data at home given that I have wifi too… but the iPhone switches wifi off when it’s in sleep mode. So if your screen is locked you’re just on the cellular network and any apps that request data at that time will do so via cellular instead of wifi. I think this is another good reason to make sure you’ve closed them down by the method above.

What if I go over my data allowance?

This is the real question: what happens if I use more data than I’m allowed? That depends on your carrier, and you should phone them up to find out. Be warned, however, that a few people I’ve spoken to say that when you call O2 you don’t get a very helpful answer… their operators don’t seem to know whether you’ll be cut off, speed limited, charged a one-off fee or forced to take out an extra bandwidth bolt-on. If you have any experience that can clear that up I’d love to know about it – please tell us in the comments.

Over to you…

I was out and about all day with my iPhone 3GS, running the latest iPhone OS. I had location services on, two twitter clients running in the background (one of which is advert supported), e-mail automatically downloading every 30 minutes, and I downloaded a few app updates over wifi. In total I used 8mb of cellular data and 100mb of wifi, but I suspect that’s because I’m quite picky about closing background aps.

How about you? Are you experiencing huge amounts of data use? If so, how many apps are you running in the background? And are you on an IOS 4+ iPhone 3G/3GS, or an actual iPhone 4? Let’s try and work this out – leave any relevant info in the comments and we might notice a pattern.

Data use monitoring, including geotagging to tell where you used what, is available via DataMan from the App store.