While Garmin and TomTom are predicted to remain global market leaders for portable navigation devices, mobile phone makers such as Nokia, Motorola, LG and Samsung are expected to show the way in the near future, the Minneapolis based market research group suggests in a report on the sector.

TRG sees the worldwide portable navigation market growing from 50 million units in 2007 to more than 500 million units in 2015.

It suggests the change in market leadership is partly due to wireless connectivity opening up new applications and services by bringing together accurate location-based data with advanced POI data including pricing, inventory and user-generated content such as ratings of local businesses.

TRG estimates 30 million dedicated Personal Navigation Devices (PNDs) were sold last year and about 20 million navigation-enabled mobile phones. It estimates that navigation-enabled mobile phones will start outselling dedicated PNDs next year, with the combined segments reaching annual sales of more than 220 million by the end of 2012.

The market researchers suggest that by 2015, Nokia could be selling 180 million devices with GPS capability, followed by Samsung and Motorola (both 70 million), LG (60 million), and TomTom and Garmin both 25 million.

Corresponding figures for last year are said to be 9 million units sold by TomTom, 8 million by Garmin, 7 million by Mitac, 5 million by Nokia and 4 million by Mio/Navman.

"In the years to come navigation-enabled mobile phones will be used for auto navigation, pedestrian navigation and many other types of location-based services," says Egil Juliussen, principal analyst for TRG. "This opens up a new world of services and capabilities".

Recent acquisitions by TomTom and Nokia point the way toward the coming battle for the GPS consumer, according to Juliussen.

"Required for success in the GPS market of the future will be connectivity, inexpensive maps and rich point-of-interest content  addresses alone will not be enough", he adds.

Garmin and TomTom are adding connectivity to their devices, he notes, and mobile phone makers are adding maps. "A large volume market for inexpensive, dedicated navigation devices will live on past 2008," Juliussen says, but survival for TomTom and Garmin may mean finding a way to compete for smartphone users.