Office Communications Server 2007 R2 provides users of mobile devices with the following capabilities:

• Instant messaging (IM)
  
  
• Presence
  
  
• Corporate directory search, which leverages your existing computer infrastructure to communicate seamlessly with users inside the corporate firewall. Mobile device users can search the corporate address book and initiate IM and conferencing sessions, identify presence information for specific users, and then place calls directly from the search results. This feature provides a secure connection to the corporate address book and negates the need to download the entire address book locally to the mobile device.
  
  
• Federation support, which enables mobile device users to identify presence information and engage in IM conversations with federated partners and users of public IM service providers such as MSN or Yahoo!.
  
  
• Integration with specific feature phones and BlackBerry devices, which provide unique capabilities, including differences in key mappings, display size, and other network characteristics. IM and presence information is now available on specific feature phones and BlackBerry devices. A feature phone is any phone that is not considered a smartphone or PDA phone. The mobile solutions embedded in Office Communications Server 2007 R2 are portable across many different devices.
  
  

Office Communications Server 2007 R2 enables users who run a supported version of a unified communications client on their mobile device to send and receive calls as though the telephone on their mobile device were another unified communications client in the enterprise network. You can enable users to set up and control Enterprise Voice calls over their cell-phone providers’ circuit-switched networks by enabling enterprise cellular telephony. You enable enterprise cellular telephony, also known as outside voice, by activating Outside Voice Control, a new unified communications application, when you deploy your Enterprise pool or Office Communications Server 2007 R2 Standard Edition server.

Outside Voice Control provides Enterprise Voice functionality and call control to mobile phones that are not otherwise enabled for Enterprise Voice. Outside Voice Control acts as an intermediary to connect mobile devices and unified communications endpoints. The mobile devices must be running one of the following unified communications clients:

• 2007 R2 version of Microsoft Office Communicator Mobile for Windows Mobile.
  
  
• Microsoft Office Communicator Mobile for Java, which is a client built on the Java Platform Micro Edition for mobile devices that are not smartphones.
  
  

When a user makes a call from a supported mobile client to an enterprise peer, the user is identified by her single enterprise number or SIP URI to the enterprise peer on the other end. When Outside Voice Control is running, all calls to a user’s single enterprise number can be routed to whatever unified communications endpoint or device is available. If the user does not answer a call to this number, the unanswered call is forwarded to either the user’s Enterprise Voice mail repository or the user’s voice mail repository with the cell-phone provider.

In addition to determining whether enterprise cellular telephony support for mobile devices is required by your organization, you also need to plan to enable Enterprise Voice as well as provide support to external users. By design, all calls placed by a mobile device to the Outside Voice Control application are considered calls from external users.

For details, including a technical overview of Outside Voice Control, see Outside Voice Control Architecturein the Technical Overview of the Getting Started documentation.