Research in Motion Ltd says it is far from certain that video will become the killer app that defines smartphones, but even so the BlackBerry maker says developing more efficient delivery is necessary to prevent video from choking airwaves.

The popularity of feature-rich smartphones such as the BlackBerry, Apple's iPhone, and Motorola's Droid has surged, but they use as much as 30 times as much bandwidth as regular mobile phones to run the applications, or apps, that make them so popular.

The surge in traffic triggered by video and other apps has led to more dropped calls and choppy service. As video on smartphones becomes more popular, it is leading to more congestion, and forcing carriers to spend billions to upgrade networks and buy more wireless spectrum.

I still don't know and I don't think anyone knows if video is a killer app for smartphones, RIM Co-CEO Mike Lazaridis said at a conference hosted by a unit of Toronto Dominion Bank on Friday. I don't particularly think it is.

Lazaridis said that even if video did not become the defining app for smartphones, it is already presenting a big challenge to networks.

If you think that today's 3G as a browsing experience is a challenge to these data networks, said Lazaridis, imagine what a video streaming or download experience is going to be as these screens start to look like HD televisions in terms of resolutions.

Analysts have praised Waterloo, Ontario-based RIM for its relatively bandwidth-light BlackBerrys, which route most emails through the company's own servers. This is a legacy of the company's earlier days when it was seeking a faster, more secure mobile email service.

RIM also sends web browsing, Facebook, Twitter, and data from a wide number of BlackBerry apps through its own servers.

That makes browsing and using apps on a BlackBerry three to eight times as efficient bandwidth-wise as on the devices of RIM's rivals, said Lazaridis.

What that means for the carrier, though, is after they have committed all those billions of dollars on new network technology and new network spectrum, they can have three BlackBerrys using the same network capacity as one of the other smartphones.

Lazaridis said RIM would invest more in technology that provides efficiencies to carriers, including when it comes to video.

He pointed to RIM's 2006 acquisition of SlipStream, which specializes in data acceleration, compression and network optimization technology.

They had some amazing technologies for compressing everything from web content, documents, and video. So, you never know, the research that we do is very important, it's always borne fruit and we are hoping that we can continue to ... provide tangible efficiencies to the carriers.

(Reporting by John McCrank; Editing by Frank McGurty)

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