Section 1.2. Location Application Architectures

1.2. Location Application Architectures

Beyond the application categories, you need to be aware of application architectures when building location-based applications. Location-based applications can be built using two different architectures:

• Disconnected location-based applications

• Connected location-based applications

Let's look at each of these categories in detail.

1.2.1. Disconnected Location-Based Applications

Disconnected location-based applications contain location information and related processing framework locally on the hosted computer hard disk, which means that network connectivity is not required for the application's functionality. A typical disconnected location-based application architecture is shown in Figure 1-1.

The main advantage of this architecture is that the location data resides locally, so the applications can provide a faster and richer user experience; however, having data locally may also be viewed as a limitation for other reasons, such as the size of the application (since location data can easily grow to a few Gigabytes) and the data becoming out-of-date due to lack of frequent updates. The advantages include:

• Continuous availability of the application and data with no dependency on network connectivity

• Rich user interface

• Ideal architechture for thick client scenarios, where computing power and memory are available to handle complex processing on the client device

Figure 1-1. Disconnected location-based application architecture

However, there are also disadvantages:

• Larger application footprint

• Local location data that becomes out-of-date over time

• Different applications for different platforms (Windows versus Mobile)

• Not ideal architecture for thin client (such as web) scenarios

The decision to develop a disconnected location-based application should be based entirely on factors such as connectivity and functional richness of the application, which we will discuss in more detail later in this chapter.

1.2.2. Connected Location-Based Applications

Connected location-based applications contain location information and related processing framework on remotely located servers instead of the local hard disk, which means that a network connection is essential for the application to run. Typical connected-location based application architecture is shown in Figure 1-2.

The main advantage of this architecture is that the location data and the related processing framework reside remotely, so the applications can be lightweight. Since the applications are loosely coupled to the location data, it is easy to update the data frequently to keep it up-to-date. The advantages of this architecture include:

• Smaller application footprint

• Ideal architecture for thin client scenarios

• Easy architecture in which to keep data up-to-date

• Easy architecture in which to develop applications for different platforms (Windows and Mobile)

Figure 1-2. Connected location-based application architecture

However, there are still disadvantages:

• Architecture that requires continuous network connectivity

• Architecture in which you may be charged for each transaction in a commercial Web service scenario

Now that you have been introduced to location application categories and different architectures, let's see how Microsoft MapPoint technologies enable you to build both connected and disconnected location-based applications.