The Offline Server is a sophisticated synchronization server that shields the mobile professional from inconsistent wireless network coverage.

Along with the Mobile Server, the Offline Server and a small client-side footprint application, allow the mobile professional to do business without worrying about network issues.

The Offline Server takes care of all the scenarios in which a mobile professional operates.

Occasionally Disconnected – when the wireless signal is lost for short periods of time, usually not more than a few minutes.

The server maintains the session even though the signal has been lost with the device. When the user accesses the applications again, the same session seamlessly continues.

This solution does not involve any device-resident software, other than the standard browser on the device.

Occasionally Connected – when the user in primarily offline and only requires form inputs.

The basic architecture consists of an HTTP caching proxy running on the device. The proxy settings of the browser on the device point to this caching proxy. The caching proxy has the following key features:

• It silently caches server pages when connected.
• The cached version of a page is shown if a network connection is not available at the time the user requests to view that page.
• When the user submits data through a form, the proxy will save the data if the network is not available. The same form can be filled out and submitted multiple times when the device is disconnected.
• When connected, a form will be automatically filled if data had previously been cached in the proxy.

The main advantage of this solution is that the same application is used unchanged in both the connected and disconnected scenarios. In other words, the application developer does not need to design and implement two versions of the application, one for disconnected and one for connected.

This solution requires as small device-resident software.

Fully Disconnected – when the user is primarily offline and requires rich data and functionality on the device.

A device resident application and database is required for this solution. A synchronization mechanism allows the end user to periodically synchronize the data with the main application. Synchronize is done over the wire via software connected to a PC.

The main advantage here is that the end user can operate independent of a wireless connection at all times.