Choosing a mobile platform for business purposes is more difficult today than ever before. Only 3 years ago, things were much simpler—enterprises used Windows Mobile or BlackBerry. Today, many platforms are competing in this market segment, and the decision of which to use is much more difficult to make. As B. K. Winstead explains in his article "Smartphones in the Enterprise: Opening Pandora's Box," each platform has its strengths and weaknesses, and vendors are mostly trying to balance between consumers and business users by providing the same type of devices for both. In "Smartphones in the Enterprise," Winstead provides a big-picture view of the smartphone market; in this article, I narrow the story to one specific service: Microsoft Exchange Server integration.
Because so many enterprises use Exchange Server as a collaboration platform, the level of integration between a mobile platform and Exchange Server can be an important factor in adopting it. In addition, because Microsoft provides its ActiveSync protocol to any vendor that wants to implement it, this protocol has become standard. Almost every mobile platform now supports ActiveSync, making the choice even wider. However, many factors affect the decision of which mobile platform will best integrate with Exchange in your environment.
Integration Basics
In general, what we expect from a mobile platform is the ability to synchronize our email messages, contacts, and calendar from our Exchange mailbox to a mobile device, as well as Direct Push support. Some more demanding users will probably also expect to have tasks and maybe even notes synchronized on their mobile device. And although mobile devices are mostly focused on consuming rather than producing content, you can typically expect the ability to create or update a meeting request from your mobile device, edit a contact in your Exchange address book, create a new task or note, and perform email management tasks such as accessing other folders in the mailbox, managing out-of-office features, and more. Another nice feature to have would be Microsoft Information Rights Management (IRM) support so that you could open encrypted email messages and send digitally signed emails. Some platforms support synchronization of text messages (SMS) to the Exchange mailbox, but most platforms use their own solution to accomplish this task.
From a systems administrator’s point of view, the most important aspects of integrating a mobile platform with Exchange are device control, provisioning, and management. Various solutions for mobile platform management exist (e.g., Microsoft System Center Mobile Device Manager), but for the purposes of this article, I focus only on management policies that are available for Exchange. In Exchange Server 2010 and Exchange Server 2007, several policies are available for application on mobile devices through the ActiveSync protocol. These policies provide an acceptable level of mobile device control.
Exchange ActiveSync (EAS) lets you force password requirements to a mobile device, configure the amount of data that will sync from your Inbox and calendar, and allow or prohibit synchronization while roaming. In addition, you can control some basic application usage on the device (e.g., browser and email clients), as well as some hardware capabilities such as Bluetooth, wireless, camera, and storage card access. You can also configure allowed or blocked applications that can (or can’t) run on the device. In general, these settings provide the most important features for managing mobile devices. All these settings are mandatory, which means that if they’re applied, users can’t change them from the client side.
These policies are created on the Client Access server role’s organization level in Exchange 2010 and Exchange 2007. They’re applied on a per-user basis, which means you can create different policies for different users. However, the policies can be applied only up to the level that the mobile device supports. Policy settings that the mobile platform doesn’t support on the client side are simply ignored.
Before you decide on a mobile platform to implement in an existing Exchange Server environment, it’s helpful to know what you can expect from each platform regarding Exchange integration. In the following sections, I discuss Exchange integration with Windows Mobile 6.5, Windows Phone 7, Apple iOS 4.3, and Google’s Android 2.2.