Paul Berney from the Mobile Marketing Association talks about the group's latest mobile commerce research in this week's edition of The Fonecast. And, as usual, there's a look at all the major industry headlines from the past 7 days – from 3G data 'rationing' to the Yahoo! phone and the closure of Vodafone.net.

With a message of “We thought rationing ended in the 50s”, BT has weighed into the unlimited mobile data debate. It's started offering BT Total Broadband users unlimited access to 1½ million BT FON and BT Openzone WiFi hotspots across the UK. A downloadable mobile application to find these hotspots is also planned.

The company points out that many of its customers are also O2 mobile users "who are about to have their 3G access rationed as they upgrade to new devices".

O2 UK is the latest mobile network operator to remove 'unlimited' mobile data for new customers. Although existing customers won't be affected, any new or upgrading customers will have a fixed data allowance on their tariff and will need to choose a 'Bolt On' allowance if they want to exceed this. The new tariffs will be introduced from 24th June – when the iPhone 4 launches – although unlimited data will be available as a promotion until 1st October 2010.

The company says current usage patterns show that 97% of O2 customers would not need to buy additional data allowances as the lowest bundle (500MB) provides at least 2.5 times the average O2 customer's use.

Nokia Siemens Networks says it's been working to remove bottlenecks from O2’s mobile broadband coverage in London, helping the network meet the demands of its smartphone users.

By analysing the activity of smart devices on the O2 network and combining this with traffic growth forecasts, NSN says it's upgraded the network elements and modules identified as current and potential future bottlenecks. Adding new base stations to existing sites has helped O2 increase coverage and capacity while also conserving smartphone battery life.