Google debuts digital map features before Apple rolls out own app Welcome to the mobile mapping wars. It's the latest escalation in the heated competition between Apple and Google. The Internet search giant Wednesday showed off new features of its digital maps ahead of Apple's annual developer conference next week, but dodged questions about whether it's about to get the steel-tipped boot from Apple's iPhone and iPad. Google billed the event as "the next dimension" for its digital mapping service. The aim is to get even more people to use its maps even as Apple reportedly prepares to jettison Google as a built-in application in its mobile operating system. Apple is expected to roll out its own mapping service as a default on its devices. Google announced that in the next few weeks it's debuting offline maps to Android phones. By preloading maps to mobile devices, users will be able to navigate unfamiliar places without a data connection and without a paper map. Google also showed off plans for more detailed 3-D images on Google Earth. Google is using chartered airplanes to get aerial images of every street and structure in major cities from different angles. And it displayed new technology that allows its Street View service to go off road. The Street View Trekker is a 40-pound mounted backpack rigged with a camera that can be taken places only accessible on foot such as hiking trails and ski slopes. The Google event was choreographed to preempt Apple's annual developer conference, where some expect the company to announce its own mapping service. That could deal a significant blow to Google. Currently more than 90% of U.S. iPhone users use Google Maps. The ouster would be the latest note of discord in a souring relationship. The two rivals were allies before Google released its own Android mobile operating software in 2008 to compete with Apple's iPhone. Google's mapping service has had a prized place in Apple's iOS since the iPhone made its debut in 2007. That gave Google invaluable information about Apple device users, where they are and what they do, helping it sell more ads to local businesses. But the Wall Street Journal and the technology blog 9to5Mac report Apple will oust Google and encourage app developers to use its maps. An Apple spokeswoman declined to comment. The plan has been in the works for years, but picked up speed as mobile devices powered by Google's Android software began to outnumber iPhones, current and former Apple employees told the Wall Street Journal. Apple bought three mapping companies to help build the service. Mobile ads are the wave of the future as more users shift to the devices. Ads connected to maps or locations account for about a quarter of the estimated $2.5 billion that will be spent on mobile ads in 2012, up from 10% in 2010, according to Opus Research. Of perhaps greater concern to Google: search on the iPhone generates a significant portion of Google's mobile search ad revenue. Ten ways Apple and Google can make TV better Gen. Kamala Harris, tech giants agree on mobile app privacy