Cellphone Terms Demystified

PCS, QoS, TDMA, WAP. Are you scratching your head in confusion because you don’t have a clue what any of these abbreviations or acronyms mean? You’re not alone. Cellular terminology is rife with these terms. In this article we’ll explain some of the most prevalent acronyms and terms you’re likely to encounter in conversations about cell phones.

Bluetooth

Bluetooth technology uses short range radio frequencies to wirelessly connect devices such as PDAs, mobile phones, and computers. Devices that are within range to receive the frequency can communicate as long as they have Bluetooth technology built-in.
For example, if your mobile phone has Bluetooth capabilities, you can use it with a wireless headset. And if your computer or laptop uses Bluetooth, you can use wireless Bluetooth keyboard with your either device.

BSC (Base Station Controller)

Together with the BTS (Base Transceiver Station), the BSC links traditional wired telephone networks and wireless devices by managing frequency assignment and carrying out radio signal functions for the BTS. The BSC can connect with multiple BTSes at once.

BTS (Base Transceiver Station)

Better known as the Base Station, the BTS communicates with cell and PCS (Personal Communication Service) phones, covering one wireless service cell location, and comprises the radio transmitter and receiver. More than one BTS can connect with the BSC at once.

Cell

The cell is the physical geographic coverage area of one network’s BTS. Cells usually cover about 10 square miles, although to increase coverage density, they can accommodate macrocells, microcells, and picocells. The cell is composed of a base station that includes a tower and radio equipment usually housed in a small structure.

CDMA (Code-Division Multiple Access)

CDMA (a form of direct sequence spread spectrum communication) is a digital cellular, multiple-access technique defined in IS-95 and IS-2000 by QUALCOMM. CDMA was originally used in WWII by the British allies to thwart transmission. By transmitting over several frequencies rather than just one, CDMA uses the full available spectrum of frequencies for its users. CDMA boasts better voice and data communication capacity than other commercial mobile technologies, permitting more subscribers to connect simultaneously.

Circuit Switching

Circuit switching guarantees a dedicated line connection for transmission between two parties. It works best when you need to quickly send data that must also arrive in the same order it was sent (for instance live audio and video).

EDGE (Enhanced Data for GSM Evolution)

EDGE is a recent enhancement to GSM (Global System for Mobile Communications) giving it the ability to handle greater data rates than normally offered to users of the GSM spectrum allowing mobile providers to deliver multimedia and broadband applications to cellular users.

GSM (Global System for Mobile Communications)

The most widely used of the digital wireless technologies (TDMA [Time-Division Multiple Access], GSM, and CDMA), GSM also is the digital mobile telephone system used predominantly outside the United States (in Europe and globally). Operating at 900MHz or 1,800MHz frequencies, GSM uses a variation of TDMA and digitizes and compresses data, sending it along a channel with two other streams of user data, each in its own time slot.

iDEN (Integrated Digital Enhanced Network)

Motorola’s iDEN is wireless communications technology that integrates (in a single network) the capabilities of two-way radios, alphanumeric pagers, data/fax modems, and digital cellular telephones. iDEN is based on the TDMA and GSM structures and operates in the 800MHz, 900MHz, and 1.5GHz bands.

MMS (Multimedia Messaging Service)

MMS, like SMS (Short Messaging Service), is a means for sending messages form one mobile device to another. It is considered the new standing in mobile messaging because you can use it to not only send text, but also images (JPEG, GIF), audio (MP3, MIDI [Musical Instrument Digital Interface]), and video (MPEG). (Including from mobile phone to mobile phone, as well as from mobile phone to email address.) An MMS message has no size restrictions and therefore requires a 3G (third generation) network to send larger messages.

Packet Switching

Packet switching is a method in which a device divides data into individual packets before sending the data to a final destination. Although packets travel different routes, the device receiving the data reassembles the packets into the original transmission once everything arrives. Most WANs (widearea networks) are packet-switched based because they are more efficient for sending email and Web pages that don’t rely on real-time transmissions.

PCS (Personal Communications Service)

PCS is a completely digital wireless telephone service that operates at the 1,900MHz frequency. Usable internationally, PCS service is part of the current trend toward digital technologies that are expected to encompass digital wireless cable, digital video from broadcast satellites, digital television, and digital cameras.

QoS (Quality Of Service)

QoS (as it relates to wireless terminology) refers to the assessment of a network’s ability to provide service to network traffic over a variety of technologies. The aim of QoS is to establish priority, including dedicated bandwidth, controlled jitter and latency, and to reduce exhibits of loss while ensuring that providing priority to one flow does not result in other flows failing.

Roaming

Roaming refers to the ability of a cell phone user to accept and make telephone connections on a network outside of his home network. Roaming can only occur when the user’s home network and the visited network have previously established an invoicing structure that lets them invoice the user.

RF (Radio Frequency)

A host of wireless applications and technologies rely on RF field propagation. Within the electromagnetic spectrum, radio frequency refers to any of the frequencies associated with radio wave generation. Electromagnetic fields are created and propagate through space when radio frequency current is sent to an antenna.

SIM (Subscriber Identity Module)

A SIM is a small smart card containing programs and data, which has the A3 and A8 algorithms implemented in it. The SIM contains important user data, including the user’s International Mobile Subscriber Identity, and can also store user-defined data such as address and phone book entries. An important factor for some GSM users is the ability to move the SIM from one mobile station to another, facilitating upgrades.

SMS (Short Message Service)

While the short message described here cannot exceed 160 characters, the short message service offers a convenience delivery method for messages over mobile networks and can be considered a global mobile data service. When you send a message from one mobile device (SMS even supports roaming, both nationally and internationally), the text is stored in the central short message center, which is part of the SMS. The message is then forwarded to the destination mobile device. If the recipient is unavailable when the message is sent, the message is stored until it is sent later. If the sender chooses to do so, he may request a return receipt, whereby the service notifies him if the message sent was indeed delivered to the intended recipient. SMS uses signaling channels as opposed to dedicated channels, which means you can send and receive messages simultaneously with data, voice, and/or fax services using GSM.

TDMA (Time-Division Multiple Access)

TDMA is a digital, wireless technology that divides cellular channels into three time slots, thereby increasing load capacity. The technology was developed to boost how much data is conveyed over digital cellular telephone communications. D-AMPS (Digital-American Mobile Phone Service), GSM, and PDC (Personal Digital Cellular) all use a form of TDMA.

UMTS (Universal Mobile Telecommunications System)

UMTS aims to establish reliable, global networks that will support a broad range of voice, data, and multimedia wireless technologies. The stateof- ]the-art 3G wireless telephone system implemented in Europe, UMTS carries out wireless transmission in the 2GHz frequency and permits roaming on a global scale along with personalized features and will instantly move data over numerous networks. Depending upon location, UMTS achieves multimedia data speed rates of 144Kbps (kilobits per second) for vehicular users, 384Kbps for pedestrian users, and 2Mbps (megabits per second) for use in buildings.

WAP (Wireless Application Protocol)

WAP is a secure specification that supports most wireless networks in use worldwide. WAP enables users to instantly access data via many wireless handheld devices such as mobile phones, two-way radios, smartphones, and pagers. Although all OSes support
WAP, those engineered especially for handheld devices include PalmOS, Windows Mobile, and JavaOS. WAP makes minimal demands on memory and CPU power because it doesn’t
contain many of the more complex functions typically found in other scripting languages.
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by Douglas Schweitzer, Sc.D.