Evan Schuman's StorefrontBacktalk

One of the attractions of mobile payments—especially with in-store mobile POS—is supposed to be speed and ease-of-use. Even if you don’t buy into the argument that it’s faster, it should, at the very least, be as fast as magstripe money. But due to a mobile power supply issue, MasterCard has discovered that retailers using a smartphone as a portable POS may find that customers will need to hold their card right against the antenna, which is hardly the way it’s supposed to work.

The problem, which was discovered in internal MasterCard prototype phone testing, involves the fact that traditional POS is AC powered from a wall outlet, whereas mobile phones are powered by small batteries. (It doesn’t matter if the phone is plugged into the wall, because that AC power merely recharges the battery, which still puts out only so much power for phone operations.) Less power means shorter antenna range, which in turn means that the payment card needs to be almost touching the antenna.

“The read-rate is not what you need it to be, certainly not the 4 centimeters you expect it to be,” said John Verdeschi, Senior Business Leader of Product Development at MasterCard. “Initially, NFC in a mobile phone was envisioned around the consumer using it. But the phone wasn’t built for that. For NFC-capable mobile POS payments to occur, quite a bit of innovation still needs to take place.”

But Verdeschi said that he doesn’t expect this problem to be a major obstacle, with upgrades likely to fix the issue. Also, “the prototypes all worked off phones. A tablet (which has a greater power supply) might work better,” he said.

But Verdeschi added that tablets have their antennae in the back of the unit, an area that is typically resting in a plastic holder, making direct access to that part of the tablet difficult. Then again, if the tablet’s power supply is much stronger, that greater distance may make direct access unnecessary.