Accessing the WMS World Through a Handheld Device

Authors: Adena Schutzberg, OGC News editor and Lance McKee, OGC User editor

If you have a mobile device such as a BlackBerry 7520 or 7100i cell phone loaded with software called "Spot," you can download map images from any Web server that makes maps available through an implementation of the OpenGIS™ Web Map Server (WMS) Specification.

Skylab Mobilesystems, the German software company that developed Spot, maintains an automatically generated global list of WMS servers on its website. The number of such servers as of June 11, 2005 was 913 and the number of layers was 307736. Not all these servers are open to the public, but growth in the numbers -- and in the practical value of Spot -- continues to rise at a rapid rate as the WMS standard grows in popularity.

Skylab Mobilesystems also provides a free OGC WMS-implementing client that is
is implemented in J2ME and specifically designed for mobile devices. It was developed as a demonstration of technology and does not include all the features of Spot. It supports zooming, scrolling, unlimited layer selection, and other features. A user manual is available in German and English.

Figure 1: BlackBerry 7520 is one mobile device supported by Spot.

BlackBerry cell phones include GPS, browser, email, instant messaging and personal organizer in a single handheld device. The 7520 has a PC-style 33-key QWERTY keyboard, and both models have displays big enough to make digital maps useful. Other mobile devices are supported by Skylab's SPOT software, including the Siemens S65, BlackBerry 7290, Palm III (using the midp4palm runtime), Tungsten T3 (IBM J9 VM for Palm OS) , Nokia 6600, Sony Ericsson T616 and iPAQ Pocket PC (running IBM J9 VM for PocketPC). Skylab Mobilesystems offers integration and development services.

Like some other GPS applications, Spot centers your current position on a map, panning across the image as you move. The difference is that with Spot, the map can be a street map, a topographical map or a satellite photo that the user has accessed (probably at no cost) through an open standard interface from a remote Web map server. Also like other GPS applications, Spot offers a routing feature for navigation that will guide you to a waypoint and give you information on the distance and estimated time of arrival. You can manually add waypoints and points of interest to mark locations or you can download them from the internet. They are then displayed on the device to simplify orientation. A built-in track-logger draws the distance you covered on the map.

Spot includes an integrated Google maps layer which can be used in combination with WMS layers, but Spot does not offer support on the Google feature.

Skylab also provides a desktop application called the Skylab GPS Simulator 1.1 which generates NMEA-0183 GPS sentences and can be used in a number of ways to support Spot applications, including taking data directly from a fully featured WMS client. Other functions include GPS multiplexing, GPS log file replaying, GPS interface transformation and remote GPS bridging.

Spot is surely a sign of things to come, as the accelerating trend toward location services converges with the accelerating trend toward use of OGC standards.