It is the men’s 100m final at the Olympics, and your seat is in prime position. But just as you want to share a video or picture, just as you send that tweet, you realise you no longer have internet connectivity – or phone connection, for that matter. All networks are severely overloaded.

Millions of people are expected to flock to London during the Games, armed with smartphones and tablets to stream live content, call and text family and friends, share photos and videos, or just watch the events online.

It will put a huge strain on the UK’s mobile phone and internet networks. And it does not just affect the lucky ticket holders. Everybody in London is likely to feel the network overload, including emergency services and transport operators.

To ensure good connectivity, BT, the official communication services provider for London 2012, has been trying to prepare the networks.

According to BT, the network capacity at London 2012 will be four times that of the Beijing Games. And to increase the amount of data capacity at the Olympic venues, the Joint Operators Olympic Group (Joog) held a trial at Twickenham Stadium, with a rugby crowd of about 80,000 people.

There will more than 500,000 hot spots, mostly in the centre, which should make life easier for visitors from abroad keen to save on their roaming charges. But there is always a possibility that something, somewhere, could go wrong. This issue is not something that has just arisen as a result of the Olympics. Intermittent mobile coverage has been a problem for a while, even for those who live in London.

The common assumption is that a mobile device is always connected, but even in major cities like London your own experience will tell you that this is simply not the case. Data connectivity comes and goes as you enter tunnels, structures with thick walls or metal-framed buildings.

Whilst this is merely a nuisance when making voice calls, if an organisation has critical business processes that rely on data being transferred quickly and accurately between business systems and employees out in the field, then intermittent wireless connections are a real problem.

The new free WiFi service in 40 or so Tube stations sponsored by Virgin Media will be helpful, but will most people realise that this service is only in the station and disappears when the train is in a tunnel? Many apps are written in such a way that it is assumed that there is data coverage.

Try and use them and you either get a message saying “no network”, or you select an action and you are confronted with “please wait” and some spinning ball until you are back in coverage. If that coverage is via a new WiFi access point then your app will never recover, because it is waiting on an IP address associated with an old WiFi access point.

As soon as you leave the capital visitors to the UK will find the mobile data service patchy at best. The BBC have had to invest in a special vehicle just to track the Torch Relay using 3G. Mobile business apps generally have very different requirements from consumer apps. A key issue for developers, organisations and users is how to maintain reliable communications given the intermittent nature of mobile phone signals.

However, approaches used by many business app developers remain fundamentally flawed – some do not allow information to be ‘pushed’ to the mobile user, others will not work when the phone is ‘asleep’ or when a particular program is not on the front screen. Others might deliver the data twice, or not at all, without the sender even realising. Reliable communications are critical for reliable business processes.