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Microsoft MapPoint Web Service is the .NET way to answer these timeless questions: "Where am I?" and "Where am I going?"
by Jeff Jurvis

Tech Ed 2003 Issue

For This Solution: MapPoint Web Service SDK, Visual Studio .NET

With their limited processing power, stingy battery life, and cramped screen sizes, mobile devices such as Pocket PC handhelds, Palm PDAs, and Web-enabled phones don't make the cut as far as general purpose computing devices go. But what makes these devices shine are the applications that take advantage of their portability and versatility when users are out and about. Specifically, applications that exploit location-based services (LBS) just might be the next mobile "killer app." For .NET developers, Microsoft's MapPoint Web Service offers location and mapping capabilities through a SOAP-based XML interface that is independent of the network service provider. In this article, I'll discuss how LBS work and how you can use MapPoint Web Service to make them a part of your applications.

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When mobile devices tap into LBS applications, they can tell users where they are and provide directions to where they want to go. These location-aware applications can also proactively push bits of information tuned to users' specific locations, such as weather alerts. The United States Federal Communications Commission (FCC) and its counterpart in the European Commission are driving the implementation of LBS for emergency purposes in the U.S. (e911) and Europe (e112), but many wireless carriers see its commercial benefit too. Companies will use location awareness to enrich applications used today such as those for route logistics, meeting planning, customer relationship management, and sales force automation. The addition of mapping and routing information has the potential to improve virtually any application that contains contact or other location data.

LBS use the Global Positioning System (GPS) and wireless network infrastructure to pinpoint the locations of hardware on the network. GPS relies on a web of satellites launched in geostationary orbit by the U.S. military. The military uses the system to track ground troops and aim weapons precisely. Non-military developers use commercial GPS receivers to capture the lower accuracy signals the satellites emit, calculating the latitude and longitude of a position to within several meters in most cases, depending on the number of satellite signals the receiver finds. Network carriers use another method to determine location by using a wireless network's base stations and signal timing to locate a position with varying degrees of accuracy. GPS can locate a receiver within a few meters or less, but network carriers are struggling to meet a goal of 100-meter accuracy with other methods.

Get the Point
As the FCC and its European counterpart work to implement e911 and e112, wireless application providers are taking the opportunity to roll out LBS that know where users are automatically and tailor content for their specific locales (see Resources). One example of this technology is MapPoint Web Service, which Microsoft hosts. It's an XML Web service with a SOAP interface. Application developers and LBS providers access MapPoint over any HTTPS (HTTP plus Secure Sockets Layer) connection. There are other LBS platforms and services available, but only MapPoint uses a 100-percent .NET approach; it uses XML Web services and integrates seamlessly with Visual Studio .NET (VS.NET). MapPoint works well with VS.NET: Using the Web Services Description Language (WDSL), VS.NET generates proxy classes for all MapPoint services automatically, giving developers easy access to MapPoint methods without having to dabble with SOAP and XML Schema. Of course, MapPoint isn't restricted to VS.NET users-any application on the Web that speaks SOAP can access MapPoint's XML Web services interfaces.

These functions are available through MapPoint Web Service today, and more are expected in the future:

• Location based on address, points of interest (such as airports and businesses), latitude and longitude, and so on
• Location context (such as maps and addresses)
• Routing and driving directions
• Proximity searches (such as nearby restaurants and colleagues)
• Address verification
• Distance calculations

You simply need an address or a point of interest to pull up a map or detailed driving directions from MapPoint Web Service. In this way MapPoint Web Service is similar to MapQuest (www.mapquest.com), although MapQuest (at press time) doesn't expose an XML Web services interface. Instead, the MapQuest service relies on an HTTP CGI interface for low-volume users and C++, Java, and COM APIs for high-volume customers.