While Microsoft currently manages only their own phones using Windows Mobile OS through Microsoft's System Center: Mobile Device Manager/SC:MDM, the MDM functionality will soon be bundled into other System Center modules for production use in late 2011. In addition, Microsoft will also control iOS/Apple and Android phones, and perhaps others, a trend likely to be followed by other mobile device OS makers.
Smartphones and other mobile devices are controlled in the classic client/server model. An agent client application is initially installed on the smartphone or mobile device, sometimes in the smartphone's system software, but more often via software download provisioning. This adds client monitoring and device control. Provisioning can be as simple as a smartphone user clicking on an SMS message that has an embedded URL to the MDM resource server. Sometimes an agent is downloaded thru an "app store", emailed URL, or is initially provisioned under the auspices of a carrier or contractor.
MDM applications like Afaria (from Sybase) and Tangoe have user agent software that's downloaded in this way and smartphone agents become the focal point for communications with the desired MDM server. Microsoft's Exchange smartphone client software, ActiveSync, is sometimes used as the proxy agent for communications from an MDM server. There are also ActiveSync-like agents for MS Exchange like NotifySync for Blackberry phones that add Exchange and ActiveSync client policy control nexus for Blackberry mobile devices.
After the appropriate client agent is downloaded, it's installed onto the device. From there, the agent software examines the phone or device state, reports findings to the MDM control server, and the MDM control server then delivers instructions to the phone. The agent then makes adjustments to the phone's or device's behavior according to rules/policies dictated by selections made administratively in the MDM application via the received messages.
The smartphone user agent app periodically "phones home" or receives messages via an email or SMS proxy application to communicate the smartphone state. Messages are pushed (sent to the mobile device), where the resident agent software reacts to them, changing policy, adding or disabling features, perhaps backing up phone data, or reacting to changes.