Blackberry Enterprise Server

BlackBerry handhelds are integrated into an organization's e-mail system through a software package called BlackBerry Enterprise Server (BES). Versions of BES are available for Microsoft Exchange, Lotus Domino and Novell GroupWise. Google has made a Connector for BES which makes BES available for Google Apps as well. While individual users may be able to use a wireless provider's e-mail services without having to install BES themselves, organizations with multiple users usually run BES on their own network. Some third-party companies provide hosted BES solutions. Every BlackBerry has an ID called a BlackBerry PIN, which is used to identify the device to the BES. BlackBerry now provides a free BES service called BES Express.

A close-up of a BlackBerry's distinctive layout

BES acts as an e-mail relay for corporate accounts so that users always have access to their e-mail. The software monitors the user's local Inbox, and when a new message comes in, it picks up the message and passes it to RIM's Network Operations Center (NOC). The messages are then relayed to the user's wireless provider, which in turn delivers them to the user's BlackBerry device.

This is called push e-mail, because all new e-mails, contacts and calendar entries are pushed out to the BlackBerry device automatically and instantaneously (as opposed to the user synchronizing the data manually or having the device poll the server at intervals). BlackBerry also supports polling email, which is how it supports POP. Device storage also enables the mobile user to access all data off-line in areas without wireless service. When the user reconnects to wireless service, the BES sends the latest data.

An included feature in the newer models of the BlackBerry is the ability for it to quickly track your current location through trilateration without the use of GPS, thus saving battery life and time. Trilateration can be used as a quick, less battery intensive way to provide location-aware applications with the co-ordinates of the user. However, accuracy of BlackBerry trilateration is less than that of GPS due to a number of factors, including cell tower blockage by large buildings, mountains, or distance.

BES also provides handhelds with TCP/IP connectivity accessed through a component called "Mobile Data Service - Connection Service" (MDS-CS). This allows for custom application development using data streams on BlackBerry devices based on the Sun Microsystems Java ME platform.

In addition, BES provides network security, in the form of Triple DES or, more recently, AES encryption of all data (both e-mail and MDS traffic) that travels between the BlackBerry handheld and a BlackBerry Enterprise Server.

Most providers offer flat monthly pricing for unlimited data between BlackBerry units and BES. In addition to receiving e-mail, organizations can make intranets or custom internal applications with unmetered traffic.

With more recent versions of the BlackBerry platform, the MDS is no longer a requirement for wireless data access. Beginning with OS 3.8 or 4.0, BlackBerry handhelds can access the Internet (i.e. TCP/IP access) without an MDS - previously only e-mail and WAP access was possible without a BES/MDS. The BES/MDS is still required for secure e-mail, data access, and applications that require WAP from carriers that do not allow WAP access.

http://en.wikipedia.org/wiki/BlackBerry#BlackBerry_PIN