The components of the mobile enterprise can be arranged in different ways, depending on what you're trying to accomplish.
Mobilizing a Single Application
If you only want to make one enterprise application available to your mobile workers, you can have the wireless applications gateway functionality built into that one enterprise application. Most vendors of large enterprise applications, such as Siebel, SAP, Oracle, and PeopleSoft, have already developed this capability (see Figure 3).
Figure 3 Mobilizing one application.
An advantage to this approach: Because the company providing the wireless application gateway is also providing the enterprise application, they're intimately familiar with the application being presented to the mobile worker. The result is a look-and-feel similar to the application's desktop version. Application upgrades may also be smootheryou can rest assured that when you get an application upgrade, the mobile interface is upgraded in lock step.
A disadvantage to this approach is that only one enterprise application is made available to your mobile workers. If you want workers to be able to access a different application, they have to sign out of the first one and then sign into the second one. And because each application may take a lot of memory on the portable computing device, it may not even be possible to run more than one application on the device.
Mobilizing Multiple Applications
To make several enterprise applications available to your mobile workers, you need a wireless application gateway that's separate from any one application (see Figure 4).
Figure 4 Mobilizing multiple applications.
In this case, the wireless application gateway is provided by a company that has nothing to do with any particular enterprise application. An advantage to this approach is that you can create a separate application for your mobile workers. This is quite appropriate, since your mobile workers have different needs than those sitting in front of a desktop computer.
This separate application can extract data from several enterprise applications and present the data in a way that makes sense to the mobile worker. In other words, the mobile application fits nicely into the business processes of the mobile worker.
A disadvantage to this approach is that you have to develop a relationship with a separate vendor. Upgrades to your enterprise applications may be complicated, since you have to make sure that the wireless application gateway is compatible with the newer versions of the enterprise applications.
Subscribing to a Service
Some wireless network operators offer hosted solutions. As shown in Figure 5, they run the infrastructure needed to mobilize one or more applications. The most popular case is wireless access to email.
Figure 5 Subscribing to a service.
An advantage to the subscription service is that you pay less money up front. You also benefit from not having to operate the wireless application gateway. The network operator does this for you.
There are a few problems associated with a subscription service:
Security concerns. If the data you want to send to mobile workers is not something you want to share outside the company, the data must remain encrypted between your company intranet and the portable computing device.
By using a subscription service, you may become too dependent on one network operator. You want to retain the ability to switch operators easily. It's important to be able to switch based on services offered and on price. If you're locked into one operator, you weaken your negotiating position.
You can't synchronize your portable computing devices with enterprise applications through the wireless application gateway. This means that wireless access to these applications takes a separate path than the synchronization process. The logic may not be the same, requiring extra work to make the wireless access and synchronization compatible.