If you don't see what you're looking for, send us your word or acronym and we'll add it! 

1xRTT – 1x Radio Transmission Technology: A way to describe one version of the CDMA mobile communications system. 1xRTT CDMA is considered a 2.5G standard, allows typical transmission speeds of 60 to 100 Kbps. The next version of CDMA, EV-DO, allows speeds of 300 to 700 Kbps.

2.5G – Many people use the term 2.5G to refer to communications standards that provide more bandwidth for data-intensive applications, but that are still not "true" 3G. 2.5G standards such as CDMA2000 1x, GPRS, and EDGE allow faster Web browsing and downloads than 2G standards (the original digital communications standards), but are not as capable as 3G standards.

3G - 3G is a general term to describe the third generation of mobile phone standards and technology, superseding earlier digital networks that were called 2G and 2.5G. 3G technologies enable network operators to offer a wider range of more advanced services while achieving greater network capacity. Services include wide-area wireless voice telephony and broadband wireless data. Unlike earlier technologies, 3G standards allow simultaneous voice and data connections.

4G – A way to refer to fourth-generation wireless communications, the broadband mobile standards that will supersede 3G. While there is neither a concrete definition of 4G, nor any agreement among mobile operators or manufacturers about what it is, most analysts expect that end-to-end IP and high-quality streaming video will be among 4G's distinguishing features. 4G network standards will likely include WiMAX and WiFi.

AGPS – Assisted GPS, or A-GPS: An enhanced-performance mobile location system designed to address some of the weaknesses of GPS, the satellite-based positioning system. Because it requires an unobstructed view of at least three satellites, conventional GPS has difficulty providing reliable positions in poor signal conditions or when surrounded by tall buildings. By relying on an "assistance server," A-GPS can use nearby cellular network towers to find the position of a device. A-GPS can use cell-tower location either alone or in conjunction with GPS satellite information.

CDMA – In the mobile world, CDMA is usually meant to refer to CDMA2000, a family of mobile telecommunications standards that use a multiple access scheme for digital radio to send voice, data, and signaling data (such as a dialed telephone number) between mobile phones and cell sites. CDMA allows many simultaneous transmitters on a single frequency channel, and offers a significant economic advantage. 1xRTT CDMA is considered a 2.5G technology, while EV-DO, the next evolution of CDMA, is 3G.

EDGE –Enhanced Data rate for GSM Evolution: EDGE improves on the "packet" data system introduced by GPRS. EDGE is considered a 2.5G mobile communications standard, offering higher data rates than the first 2G GMS systems, but lower speeds than "true" 3G systems such as UMTS. EDGE transmission speeds average from 100 to 130 Kbps.

EV-DO – Evolution-Data Optimized transmission: An evolution of the CDMA standard, EV-DO (or EVDO) is designed to offer broadband-like Web browsing and e-mail, and to enable simultaneous voice and data connections. EV-DO Rev 0 is considered a true 3G standard, with typical download speeds of 300 to 700 Kbps. EV-DO Rev A and the upcoming Rev B standards offer even faster data rates (up to 800 Kbps and higher) that are capable of delivering video and other high-bandwidth content.

GPRS – General Packet Radio Services: GPRS is an extension of the GSM family of mobile communications network standards. Considered a 2.5G technology, GPRS uses data "packets" to improve on the transmission speeds of GSM, offering from 40 to 50 Kbps.

GPS – Global Positioning System: A network of specialized satellites designed by the U.S. military. Many people use the abbreviation to refer to a device's ability to use receive signals from those satellites ("My Windows Mobile phone has built-in GPS.") In any case, GPS enables phones and other mobile devices equipped with the right hardware and software to determine positioning information based on signals they receive from the GPS satellites. GPS receivers require a clear view of at least three of the satellites for accurate positioning – a drawback that spurred the development of AGPS and other enhanced technologies.

GSM – Global System for Mobile communications: GSM is the most popular family of mobile network standards in the world. Most prevalent in Europe, Asia, and other parts of the world, GSM systems include GPRS, EDGE, WCDMA or UMTS, and HSDPA. GSM transmission speeds can range from less than 40 Kbps (for the first version of GSM, or 2G) to 1.1 Mbps (for HSDPA, or Advanced 3G).

HSPA – High-Speed Packet Access: A collection of mobile telephony protocols that extend and improve the performance of existing UMTS protocols. Two standards, HSDPA and HSUPA, have been established and a further standard, HSOPA, is being proposed. The two existing standards (HSDPA and HSUPA) in the family provide increased performance by using improved modulation schemes and by refining the protocols by which handsets and base stations communicate. These improvements lead to a better utilization of the existing radio bandwidth provided by UMTS. Typical download speeds are 550 Kbps to 1.1Mbps.

IMAP -  Internet Messaging Access Protocol 4: IMAP4 is an e-mail service type that allows you to download only the e-mail subjects, and then select the messages to download. Also, you can choose to synchronize a folder of messages as well. Microsoft Exchange supports IMAP4 access to e-mail.

LBS – Location-based services: Data and directory services tied to GPS or other positioning information. LBS include white- and yellow-page lookups, business listings, points of interest, and reviews. LBS are frequently associated with navigation and mapping applications such as Live Search for Windows Mobile.

MO – Mobile operator or wireless provider: A telephone company that provides mobile phone voice and data services.

OEM – Original equipment manufacturer: Today, the acronym OEM usually refers to a manufacturer who purchases essential technologies (either hardware or software) from another maker, and then incorporates them into its own product, which it then sells to consumers or retailers (thus "re-selling" the other company's component). For example, Samsung, HTC, and Motorola are considered OEMs in relation to Microsoft. Those companies purchased a license to incorporate Windows Mobile into their mobile phones, and then "re-sold" Windows Mobile in phones with Samsung, HTC, or Motorola brand names.

POP3  - Post Office Protocol 3: The most recent version of a standard protocol for receiving e-mail. Typically, client software such as Windows Live Hotmail uses the POP3 protocol to connect to an e-mail server, retrieve all messages, store them on the user's PC as new messages, delete them from the server, and then disconnect. In contrast, the newer IMAP e-mail protocol usually leaves messages on the server, and can offer a continuous connection to the e-mail server. Many subscribers to individual Internet service provider e-mail accounts access their e-mail with client software that uses POP3.

SD -  Secure Digital: A flash (non-volatile) memory card format developed by Matsushita, SanDisk, and Toshiba for use in portable devices. Today it is widely used in digital cameras, handheld computers, mobile phones, GPS receivers, and video game consoles. SD card capacities range from 8 MB to 4 GB and from 4 GB to 32 GB for SDHC cards (as of 2008). SDHC cards require an SDHC capable device firmware, generally not found with older devices.

SIM - Subscriber Identity Module: A small smart card used in many GSM-based mobile devices to store both programming and information. SIM cards securely store network-specific information used to authenticate and identify subscribers on a cellular network, including a unique subscriber identifier and authentication key. SMS messages and contacts can also be stored. SIM cards can be moved from phone to phone.

SMS - Short Message Service: SMS is a communications protocol allowing the interchange of short text messages between mobile phones. SMS as used on modern handsets was originally defined in the 1980s as part of the GSM series of standards. It offered a means of sending messages of up to 160 characters. Today, the character limit still applies, but CDMA and other networks all offer SMS.

SMTP - Simple Mail Transfer Protocol: A protocol for sending e-mail messages between servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an e-mail client using either POP or IMAP. In addition, SMTP is generally used to send messages from a mail client to a mail server.

TCP/IP - Transport Communications Protocol/Internet Protocol: The communications protocol that Windows Mobile and other operating systems use to communicate to the Internet, as well as to synchronize via ActiveSync or Windows Mobile Device Center.

UMTS – Universal Mobile Telecommunications System, also know as WCDMA: A 3G and Advanced 3G mobile communications technology. UMTS incorporates both W-CDMA and GSM standards for communications, and was designed as the 3G successor to GSM. It enables very high-speed data transfer for data-intensive applications. Transmission rates range from 550 Kbps to 1.1 Mbps.

WiMAX – Worldwide Interoperability for Microwave Access: A telecommunications technology aimed at providing high-speed wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. Some cellular companies are evaluating WiMAX as a means of increasing bandwidth for a variety of data-intensive applications. WiMAX is considered a "pre-4G" technology.

WMDC – Windows Mobile Device Center: An application for Windows Vista that serves the same function as ActiveSync in Windows XP.