At every turn in the mobile world, you see online services being launched, and applications that tie into existing services. Examine the top ten things that a typical iPhone or Android phone owner does and I'd bet that over half (if not 7 or 8) involved Internet access. The number's arguably lower in the Symbian world (more built-in/local functionality), but the trend is clear - software and service designers are assuming that mobile Internet access is a given. But what happens when the (signal) bars run out?

Let's get this into perspective. The UK is quite a small country. It's a lot less than a thousand miles in any direction. Compared to France or India (for example), the UK is smaller and easier to 'cover'. It's certainly a tiny fraction of the size of the USA - yet it's from the latter that mobile platforms come that assume always-on Internet access - paradoxically.

I live in a major UK city and as long as I stay within suburban areas then I get a decent 3G signal (on Vodafone, in this case). If I then venture a few miles north or south, the 3G usually gets dropped and I'm back to good ol' GPRS, running at sub-dial-up speeds. But at least it works, after a fashion.

If I then go behind the wrong hill. If I then visit my parents in Somerset. If I then take my family to the local theme park. If I then visit my relatives in rural Yorkshire. If I go camping in Devon... in ALL these scenarios, only veering a few tens of miles from the beaten track, I'm left with NO signal whatsoever. No voice, no data, no action.

And it's not just my network. Vodafone are widely considered to be the best of the UK networks in terms of coverage. What on earth must the other networks be like? And the above scenario was all with a smartphone with largish network aerial and plastic back. What would happen when using a device with lots of metal in its case (e.g. see the problems the HTC Legend has been having)?

In other words, even using the best possible network and best kit, there are still far too many occasions when there's simply no mobile data available. Don't get me wrong, this isn't a rant against the networks - I can only imagine how much of a problem it is to try to cover every last inch of every country. This is a rant against the always-connected-assumed mentality.

A simple example of this is Google Maps. You need it most when you're lost in the middle of nowhere - at which point you find that your nice strong 3G signal from 15 minutes ago in town is now a pitiful one bar of GSM and that data is trickling down at less than 1KB/sec.

Surely things are even worse in bigger countries? In which case, why aren't more applications using local storage and caching much more? Google Maps, for example, does do a little caching, but only while it's left open. So if you'd browsed that particular spot earlier in your session at that specific map resolution then there's a good chance the maps will be cached. But that's a long shot.

Things aren't completely cured by using Ovi Maps, either. You may well have preloaded all the streets in your country, but you'll need data for the Assisted GPS to work, in order to locate you before your wife and kids get fed up waiting. And if you're trying to find something other than a street name then Ovi Maps is going to want to go online to search - which will also not work.

In my experience, even when you're down to the last bar of GSM signal, a voice call may still work - so you're unlikely to be totally cut off. But you'll have to go without the mass of communications functions that you may have come to rely on: Twitter, Email, Facebook, News, Weather updates, and so on. Then there's streaming music and video options, if you're really into the connected lifestyle.

All of which may seem a little obvious - you're out of signal area, you're out of touch - big deal. But, as with the Maps example, above, there are some apps and services which are a big deal. What about keeping all your most precious data and snippets in Evernote? Great idea, you'll never have to worry about backing up - but you'll also not be able to retrieve any of the data when you can't get online, possibly when you need it most. Ditto if you're accustomed to relying on bits of information being remembered by Gmail - you can't search Gmail if you're not online.

And, just as obviously, if you're in the middle of nowhere, lost, hungry and devoid of data signal, then there's a good chance that Web also won't work. Which means you can't look up the 'web site' of the place you're trying to get to. Or run one of the new breed of 'find something around you' services.

All the above are annoying in themselves - they're intensely frustrating when you have a family in the car and they're all staring at you and your 'magic box', expecting you to conjure information from the ether, like you usually do.

Is there a solution to all this? Are there lessons to be learned? After a fashion, yes.

As a user:

1. Don't rely on the Internet while travelling.
2. For mapping, have paper maps in the car trunk as a backup. Plus a guide book or two, for emergency accomodation advice.
3. For public transport, have routes, reference numbers and reservations printed out beforehand (and not just in your Gmail account).
4. For office work, don't rely on Google Documents - download copies of important items onto your device if you think you'll need them while mobile, and work on them there.
5. Don't assume Internet access for entertainment - listen from local files on your memory card - your battery will thank you.
6. Take an emergency charger or spare battery with you - working at the very limits of coverage really, really drains your main smartphone battery.

As a developer: 

1. Don't assume that the user has an Internet connection at all times.
2. Allow for a clean handover between online and offline modes
3. Cache as much relevant data as possible (e.g. Ovi Maps could cache a small database of likely POIs for your current area while it still has a connection?) and at least allow the option of caching this data between sessions (i.e. storing it on mass memory, for example)

What happens when the bars run out? Even as a Symbian user, you're currently rather hamstrung in terms of functions. But here's hoping that a combination of better networks and more intelligent software will come to our aid - at least to some degree.

Steve Litchfield, All About Symbian, 5 May 2010