J-STD-008
A standard that describes a cell system that uses a CDMA link and operates at 1900 MHz. It is similar to, but not identical to, IS-95.

J2ME
Java 2 Microedition, a technology developed by Sun MicroSystems. For more information, browse to The Java ME Platform - the Most Ubiquitous Application Platform for Mobile Devices

KB or Kb
Kilobyte is a term denoting 1024 bytes, roughly equal to 8 kilobits.

Kbps
Kilobits per second - A speed measurement for the transmitting of data (see bps).

KHz
A unit of measurement for frequency equal to 1000 Hertz.

LAN
A Local Area Network, or LAN, consists of a group of inter-connected computer terminals or nodes, often co-located and managed from a single point as a single network, such as an organization or business might deploy for sharing and managing information internally.

Layer
Usually refers to the OSI specification dividing any communicating system into 7 layers, each having a different functionality. Layer 1 is the physical layer (radio), layer 2 is the link layer, and IP could be assimilated as layer 3 (network layer). TCP is considered layer 4, the transport layer. For more information on the OSI 7-Layer Model browse our AIRSOURCE Knowledgebase at https://support.airdesk.net > solution #375

LBS (Location-Based Services)
Services or applications that center around a user’s location in a mobile environment. Location-based services utilize location-sensitive technology, such as Global Positioning Satellite (GPS) or network-based solutions, to deliver services or applications to a wireless device such as a mobile phone. These services can include finder applications that let mobile phone users locate friends or family, businesses or landmarks. They can also deliver maps, directions, or traffic reports.

LIG (Lawful Interception Gateway)
The lawful interception gateways provides a mechanism whereby designated security or law enforcement agencies can intercept GPRS traffic, much as voice “wiretap” facilities are provided in mobile networks. Today. Legal authority to use this mechanism as well as safeguards to protect privacy will vary from country to country.

Lightning Protector
A device designed to divert large surges of current such as a lightning strike from reaching the RF equipment. There are many types of lightning protectors including Quarter Wave Stub and Gas Discharge Tubes.

Link layer
This is the part of the protocol managing the direct delivery between two devices on a specific physical layer (coaxial bus, point to point link, radio). This includes packetization and addressing. Most of this is implemented in the MAC in a WLAN.

LMDS (Local Multi-point Distribution Services)
LMDS broadband services operate over the 28-31 GHz bands in the US and provide high data rates, but only over a relatively short distance of three miles.

LMU
Location Measurement Unit

Location-based Applications
Location-based applications allow end users to find community services near their location such as hotels, restaurants, pharmacies, banks, gas stations, and many other neighborhood services. These applications are effective in both consumer and business markets.

Location-based Service
A service that tracks a cellular phone user’s location within the mobile network and provides a variety of additional services: E911 service automatically notifies an emergency center of a user’s location when he/she is in an urgent situation. Location Based Billing Service provides a discount rate when calling and receiving at a specific area. Tracking service grasps and manages the location of a person and an object. Location Based Information Service provides local information on the area near subscribers. All these services are made possible by a wide range of technology; GPS + Cell based (location) Tracking, Measuring Signal Attenuation (between a subscriber’s hardware and a base station), Server Aided GPS System, Assisted GPS Tracking made of DSP Software based device and TOA (Time Of Arrival)/TDOA (Time Difference Of Arrival) Tracking. Server Aided GPS System was developed by SnapTrack, tested and verified at CDMA, GSM networks and is now under commercialization.

Long code
In CDMA is a chip sequence that is 240 chips long, which repeats every 41.4 days. Its primary purpose is to assist in spreading the signal, to make spread spectrum work more efficiently. The Long code used on the reverse link is usually modified using the phone’s ESN when in a call.

MAC (Medium Access Control)
This is the part of the radio device managing the protocol and the usage of the link. The MAC decides when to transmit and when to receive, creates the packets headers and filters the received packet.

MAN
Metropolitan Area Network. A regional computer or communication network spanning the area covered by an average to large city.

MB or Mb (Megabyte)
Megabit is a term denoting approximately one million bits. There is some argument as to whether a megabit should signify one million bits or 1, 048, 576 bits since the latter number more closely adheres to the binary arithmetic that lies at the heart of computer technology. On the other hand “mega” has long signified one million in the decimal system and is most widely understood in this way.

Mbps
Megabits per second describe the rate of transfer of data as measured in megabits.

MC-CDMA
Multi-carrier Code Division Multiple Access. This 3G standard is an evolution of IS-95, combining three IS-95 carriers to form one wideband carrier. It is also known as cdma2000.

Megahertz (MHz)
A unit of measurement for frequency equal to 1, 000, 000 Hertz. 1 million cycles per second.

Micro browser
A Web browser optimized to run in the low-memory and small-screen environment of a Net device.

Micro Cells
In large cities, mobile phone operators are increasingly converting their networks to small cell structures (cells). Larger mobile phone cells with diameters from 10 to 20 miles are “macro cells”. Radio cells in the mid- range (with a diameter of about one mile) are “micro cells”. Even smaller are pico cells, which often only range a few hundred meters. The miniaturization of radio cells allows more subscribers to be supplied over a given area.

MMDS (Multi-channel Multi-point Distribution Service)
a fixed wireless service for data, voice and video which operates in the 2.5 GHz band in North America and in the 3.5 GHz bandwidth internationally.

MMS (Multimedia Messaging Service)
A type of messaging comprising a combination of text, sounds, images and video.

MNO (Mobile Network Operator)
An operator of a wireless network for mobile phones.

MO (Mobile Originate)
A call outbound or originating from a mobile device

Mobile Antenna
Refers to any antenna mounted on a vehicle. Includes a radiating element and a mechanism to fix the antenna to the vehicle.

Mobile IP
Mobile IP is an Internet protocol designed to support host mobility. Its goal is to provide the ability of a host to stay connected to the Internet regardless of their location. Mobile IP is able to track a mobile host without needing to change the mobile host’s long-term IP address. For a survey paper on Mobile IP browse to http://www.cis.ohio-state.edu/~jain/..._ip/index.html

Mobile radio network
Network using radio frequencies to connect mobiles to the fixed or mobile network.

Mobitex
An open global first-generation standard for narrowband wireless packet switched communications in the 900MHz (and lower) band for mobile terminals and fixed-to-point communications.

Modem
A device, which modulates (mo-) and demodulates (-dem) the signal carrier on a communications channel. When binary data (information as it is stored in a computer) is transmitted from one computer to another, modulation varies the carrier to represent the data during transmission, and demodulation interprets the variations of the signal so as to recapture the original information.

Modulation
A process by which information (e.g. voice, music, data) is added to a carrier signal, such that the signal receiver can extract the information via a process called de-modulation. Three commonly used modulation techniques are Amplitude Modulation (AM), Frequency Modulation (FM), and Phase Modulation (PM).

Monopole
Literally, one pole, such as a vertical radiator operated against the earth or a counterpoise. A handheld rubber duck type of antenna will most likely be a monopole.

Mount
A mount is the device onto which a mobile antenna attaches. It is the mechanical and electrical interface between an antenna and the vehicle.

MS (Mobile Station)
A mobile transceiver or mobile radio enabled device operating within a mobile network. Originally this term referred just to cell phones or handsets, but now include mobile radio modems or any device containing a mobile radio modem as well.

MSC
The mobile switching center or MSC provides basic telephone switching services and links a mobile or cellular network with the public telephone system or PSTN.

MT (Mobile Terminate)
A call inbound or terminated to a mobile device.

MTBF
(Mean Time Between / before Failure / Faults) The average time (usually expressed in hours) that a component works without failure. It is calculated by dividing the total number of failures into the total number of operating hours observed. The term can also mean the length of time a user may reasonably expect a device or system to work before an incapacitating fault occurs.

MTSO (Mobile Telephone Switching Office)
The central switch that controls the entire operation of a cellular system.

Multi-access portal
A service that provides Web access from a range of mobile, fixed and cable television devices.

Multi-Band
Describes the facility of certain mobile stations to operate over two or more frequency bands

Multi-Mode
Describes the facility of certain handsets to operate over more than one wireless technology. e.g. GSM, CDMA, TDMA, and AMPS. Dual mode AMPS/CDMA phones and AMPS/TDMA phones are still generally available from the original cellular network operators who continue to offer AMPS services in tandem with the newer digital network technologies.

Multipath
Refers to a common phenomenon in RF where the signal arrives multiple times at the receiver at slightly different times. If you’ve used a TV with an old-style rabbit-ear antenna, you’ve sometimes seen ghosting, where the video seems to have echos of itself extending to the right. This is due to multipath. Usually the strongest path is nearly direct from the transmitter to the receiver. However, the signal can reflect off of other objects (large buildings are particularly good at this) and that signal arrives somewhat later, since it follows a somewhat longer path. For most kinds of RF multipath is a form of interference and degrades the signal. CDMA is unique among cellular transmission standards in that it actually uses multipath to its advantage by using fingers in the rake receiver. As a result, CDMA performance is actually improved by multipath.

Multiple Access
Multiple Access refers to techniques used in wireless telecommunication systems that permit sharing of limited radio frequency resources among a large numbers of potential users, not all of which will require simultaneous access. The key assumption is that not all users will require simultaneous access. All the common wireless technologies, e.g. CDMA, FDMA, GSM, and TDMA, apply these techniques.

MVNO (Mobile Virtual Network Operator)
A company that, to end-users, appears to be a wireless network operator. Unlike a standard wireless carrier, however, an MVNO does not own the Base Station Subsystem (BSS) that Mobile Network Operators (MNO) do. MVNOs also may not necessarily own other infrastructure one normally associates with an MNO, such as MSCs, and Home Location Registers (HLRs). More importantly, MVNOs do not hold licenses to radio spectrum; instead they purchase network capacity from wireless carriers that do hold licenses and which do operate the network infrastructure necessary for wireless phone communication.

NAA
Network Access Application

NAM (Number Assignment Module)
The electronic memory in the cellular phone that stores the telephone number. Phones with dual- or multi-NAM features offer users the option of registering the phone with a local number in more than one market.

NAMPS (Narrowband Analog Mobile Phone System)
A proposed new standard for cellular radio. NAMPS combines current voice processing with digital signaling. According to Motorola, MAMPS triples the capacity of today’s cellular AMPS system, reducing the number of dropped calls and offers a range of new performance enhancements and digital message services. NAMPS has given way to the newer, more advanced, digital technologies. See GSM, TDMA and CDMA.

Narrowband
A classification of the information capacity or bandwidth of a communication channel. Narrowband is generally taken to mean a bandwidth of 64kbit/s or less.

NAT (Network Address Translation)
The translation of an Internet Protocol address used within one network to a different IP address known within another network.

Net mask
A Wireless Glossary, Acronyms and Abbreviationssystem for designating hierarchies of networks and sub-networks within the Internet has evolved that uses net masking to simplify routing and local network administration. The purpose of a net mask is to specify which part of an IP address specifies a specific host and which part designates a subnet to which the host belongs.

NIC (Network Interface Card)
Otherwise known as a wireless LAN card. In most cases, this board or PCMCIA device is added to a computer or portable device to give it wireless LAN capabilities, but increasingly, manufacturers are incorporating network interface circuitry into portable devices, thereby eliminating the need for a separate network interface card.

NMO
Perhaps the most prolific of all mobile antenna mounts is the NMO. It enables one mount, inserted in a drilled hole in the vehicle body, to be used over the lifetime of the vehicle with many screw-on antennas.

NMT
Nordic Mobile Telephone System, the first mobile telephone system with automatic switching. The initiator of 1G.

NNI
Network to Network Interface

Node B
A 3G name for base station

Noise
Any unwanted signal. May include background noise, interference, or transmissions from nodes not belonging to the network. See also SNR (Signal to Noise Ratio).

Noise floor
In CDMA refers to the part of the incoming signal that is unusable. The primary component of the noise floor on the forward link is signals being sent by the cell to other phones in the same sector, and to a lesser extent other nearby cells and sectors transmitting to their phones. The primary component of the noise floor on the reverse link is other phones transmitting to this cell or to others nearby.

Non-Wireline
See Wireline.

NSS (Network SubSystem)
The Network Switching Subsystem or NSS refers to that part of a GSM network primarily responsible for interconnection to the Public Service Telephone Network (PSTN), collecting charging information, maintaining subscriber profile and service information, wide area mobility management etc. The principal components are the MSC, or switch, the Home Location Register (HLR) and the Visitor Location Register (VLR).

NTIA
National Telecommunications and Information Administration. The US federal government’s spectrum management authority.

OEM
Original Equipment Manufacturer

OFDM
Orthogonal frequency-division multiplexing is a method of digital modulation in which a signal is split into several narrowband channels at different frequencies. OFDM is similar to conventional frequency-division multiplexing (FDM). The difference lies in the way in which the signals are modulated and demodulated. Priority is given to minimizing the interference, or crosstalk, among the channels and symbols comprising the data stream. Less importance is placed on perfecting individual channels.

OHG
Operators Harmonization Group. A group of industry operators established to meet on harmonization issues. The group is working towards a way of harmonization between CDMA2000 and W-CDMA.

Omnidirectional
An antenna providing a 360-degree transmission pattern. This type of antenna is used when coverage in all directions is required.

Orthogonal
(“composed of right angles”) is a technical term referring to a certain special characteristic of the long code, the short code and the Walsh codes. It refers to the fact that, for instance, if you take any two Walsh codes and XOR them together, the result will be 32 1’s and 32 0’s. But if you XOR a Walsh code with itself, the result is 64 0’s. The short code and long code are orthogonal to themselves at different offsets. What this means is that if two short codes are synchronized, then the XOR of them is all 0’s. If they are offset from each other, by any amount, then the XOR of them is about half 1’s and about half 0’s. The long code is also orthogonal to itself. This was done deliberately and without it CDMA wouldn’t work. This fundamental characteristic of the long code, short code and Walsh codes is what makes it possible for the rake receiver to separate out the chip sequence intended for this phone from the ones being sent to all the other phones.

OSI (Open Systems Interconnection)
OSI is a standard description or “reference model” for how messages should be transmitted between any two points in a telecommunication network. Its purpose is to guide product implementers so that their products will consistently work with other products. The reference model defines seven layers of functions that take place at each end of a communication. Although OSI is not always strictly adhered to in terms of keeping related functions together in a well-defined layer, many if not most products involved in telecommunication make an attempt to describe themselves in relation to the OSI model. It is also valuable as a single reference view of communication that furnishes everyone a common ground for education and discussion. For more information on the OSI 7-Layer Model browse our AIRSOURCE Knowledgebase at Numerex Techworx - Numerex - the M2M 'Partner of Choice' for continued and safe connectivity. solution #375

OSTL (One Time Subsidy Lock)
A password that allows a user to configure parameters that are normally not accessible. The OTLS is in effect for only one session. See also MSL.

OTDOA
Observed Time Difference of Arrival is similar to E-OTD, but may provide lower yield (percentage of successful position determinations) and operates only on UMTS networks. Accuracy: 50-200m.

Packet
When a quantity of data is to be transmitted over a network, it is sometimes divided into groupings of sequential bits called packets. Communications and error control information is then added to the packet prior to actual transmission. At the data destination, the extra control information is removed and the original information is reconstructed from the individual packets.

Packet Switching
A generic term for data communications techniques that move data from place to place in a network on an individual packet basis rather than by allocating a dedicated link. Packets can be routed independently so as to maximize network capacity and to take advantage of routing alternatives to work around network bottlenecks or outages. A method of transmitting messages through a communication network, in which long messages are subdivided into short packets and routes to its final destination.

Page
Is a message sent by the cell system on the paging channel to a particular phone that says that there’s an incoming phone call. When the phone receives a page, it sends a message to the system requesting a traffic channel, and when it is granted one it then rings to tell its owner that a phone call is waiting.

Paging channel
In CDMA is a channel used by the cell to send pages, which indicate incoming calls, to the phone. The Paging channel also carries other information, such as indications of voice mail, SMS indications, plus housekeeping information such as the PN Offsets of all nearby cells and sectors.

PAN (Personal Area Networks)
A Personal Area Network typically covers the few meters surrounding a user’s workspace and provides the ability to synchronize computers, transfers files and gain access to local peripherals like printers and a range of pocket hardware. A technology like Bluetooth may enable wireless PAN.

Parabolic Antenna
An antenna consisting of a parabolic reflector and a radiating or receiving element at or near its focus. A parabolic antenna is very directive and includes a preliminary source and a parabolic reflector to focus the energy.

PCB
Printed Circuit Board.

PCN (Personal Communication Network)
This standard corresponds to a high-frequency version of the GSM standard.

PCS
Stands for personal communication system and according to the FCC it refers to any portable phone system that operates in the 1900 MHz band allocated for such systems. Among others, this includes J-STD-008, GSM and IS-136. Any of several types of wireless, voice and/or data communications systems, typically incorporating digital technology. PCS licenses are most often used to provide services similar to advanced cellular mobile or paging services. However, PCS can also be used to provide other wireless communications services, including services that allow people to place and receive communications while away from their home or office, as well as wireless communications to homes, office buildings and other fixed locations.

PDA (Personal Digital Assistant)
A handheld computer that can be used for simple Personal Information Management (PIM) functions. As PDAs have become increasingly sophisticated, some are poised to usurp the place of subcompact notebook computers, and can be used for more complex functions such as viewing and editing documents, spreadsheets, and presentations. PDAs run on a variety of Operating Systems (OS), the most common of which are the Palm, Microsoft Pocket PC, Symbian, and Linux.

PDC (Personal Digital Cellular)
A Japanese standard for digital mobile telephony (800 MHz and 1500 MHz bands).

PDE
Position Determining Entity

PDP (Packet Data Protocol)
The primary protocol(s) used for packet data communications on a packet data network, e.g. TCP/IP on the Internet.

PDP Context
In order to use a GPRS network, the MS and the Network must negotiate a set of parameters that support the flow data traffic to and from the MS in an orderly fashion. Among the parameters that must be set are: the identifier of the external packet data network the MS wishes to communicate with, a PDP address recognized in that network (e.g. an IP address for service over the Internet), the address of the GGSN, QoS and so forth. The set of these parameters taken together is called a PDP context. Individual parameters may change over the life of the context as the MS moves about the network. Likewise an MS may have several contexts active at one time so as to be able to simultaneously set up and maintain sessions in more than one network, e.g. the Internet and a Corporate Intranet.

PDU
Protocol Data Unit. OSI (Open Systems Interconnection) terminology for a generic “packet”. A PDU is a message of a given protocol comprising payload and protocol-specific control information, typically contained in the header. PDUs pass over the protocol interfaces which exist between layers of protocols (per OSI model). Basically, PDU is OSI terminology for “packet”. A PDU is a data object exchanged by protocol machines (entities) within a given layer. PDUs consist of both data and control information that allows the two to coordinate their interactions.

PFFR
Predicted Fundamental Failure Rate

PHS (Personal Handyphone System)
Digital mobile telephone system according to Japanese standard (1900Mhz).

Physical layer
The part of the device interacting with the medium. For a wireless LAN, the physical layer is the radio.

Pico
Cell Very small cell in a mobile network for boosting capacity within buildings.

Pilot channel
In CDMA is a special channel that the cell transmits constantly. It is not modulated using the long code and it uses Walsh code channel 0, which is all 0’s, and it transmits a bit pattern of all 0’s. That means that what it contains is the short code at the phase being used by the cell. System acquisition by the phone begins by locating the pilot channel, and this permits the phone to synchronize its short code with the cell. After this, the phone looks for the sync channel.

PIM
Personal Information Management functionality started with the Filofax, with all your personal data held in paper form in a single package. The personal organizer came along to store the data electronically with the ability to store the same information on your PC and synchronizes the two. The same functionality is now finding its way into mobile phones, which also have the synchronization capability.

PIN
Personal Identification Number.

Planar Array
An antenna in which all of the elements, both active and parasitic, are in one plane.

PLL (Phase Locked Loop)
Circuit technology (or a circuit using that technology) in which the circuit is operated at an arbitrary frequency by forming a loop circuit that synchronizes the frequency phase.

PLMN (Public Land Mobile Network)
Today the term ‘Public Land Mobile Network’ refers to any wide area wireless or ‘cellular’ phone system. In the GSM world, inter-PLMN connections are generally restricted to other GSM networks providing similar services.

PN Offset
See Short code

PN Roll
See Short code

Point-to-Multipoint
A communications channel running from one point to several other points.

Point-to-Point
A communications channel running from one point to another.

Polarization
The sense of the wave radiated by an antenna. This can be horizontal, vertical, elliptical or circular (left or right hand circularity) depending on the design and application.

Port number
TCP and UDP provide an address mechanism, the port number, for identifying different applications communicating from the same IP address. Thus an active web browser and an independently active mail program operating from the same IP location would typically use different port numbers so that packets are correctly delivered to specific applications.

POS (Point-of-Sale) Terminal
a device that accepts credit/debit card payments.

Power control bits
In CDMA are chips which are altered in the forward link to permit the cell to adjust the transmit power of the mobile phone on the reverse link while in a call. They are transmitted 800 times per second and cause the phone to increase or decrease it’s transmit power by a small increment.

Printed Antenna
All antennas made by means of a printed circuit process.

PRL
Stands for Preferred Roaming List, and it is used by the phone to locate different cell systems. For a more detailed description log onto our AIRSOURCE Knowledge base > AIRDESK Solution number 360.

Proactice RUIM
RUIM, which is capable of issuing commands to the Terminal.

Proactive RUIM session
Sequence of related UTK commands and responses. A proactive RUIM session starts with the status response ‘91 xx’ (proactive command pending) and ends with a status response of ‘90 00’ (normal ending of command) after Terminal Response.

Protocol
Formal set of rules governing the format, timing, sequencing, and error control for data exchanges between two or more communications nodes. Note that many protocols may be required and regularly used on network.

Proxy
In an enterprise that uses the Internet, a proxy server is a server that acts as an intermediary between a workstation user and the Internet so that the enterprise can ensure security, administrative control, and caching service.

PSAP (Public Safety Answering Point)
The state-funded call center that receives all 911 calls and routes the calls to the appropriate emergency agency.

PSD
Packet Switched Data is a technology where the communication “pipe” is shared by several users, thus making it very efficient. The data is sent to a specific address with a short delay. This delay depends on how many users are using the pipe at any one time as well as the level of priority requested for your information. Charging is made according to the volume of data and not the duration of the connection. PSD is the technology used for data communication across the Internet and because it maximizes the use of the network, this type of communication will eventually be used even for voice communication, with a high level of priority assigned to that form of traffic.

PSK (Phase Shift Keying)
Phase-shift keying (PSK) is a method modulating a carrier signal by rapidly changing or shifting the signal wave phase as a method of sending information. Patterns of 1’s and 0’s can be sent via prescribed phase shifts.

PSTN (Public Switched Telephone Network)
The PSTN refers to the world’s collection of interconnected, voice-oriented public telephone networks, both commercial and government-owned. It’s also referred to as the Plain Old Telephone Service or “POTS”.

PTCRB (PCS Type Certification Review Board)
the purpose of the PTCRB is to provide the framework within which GSM Mobile Equipment (ME) Type Certification can take place for members of the PTCRB. This includes determining the test specifications and methods to implement Type Certification for GSM Mobile Equipment. The goal of the PTCRB is if one carrier approves a Mobile Station (MS) then this MS is allowed to roam on all networks wherever they have roaming agreements in the GSMNA (GSM North America). PTCRB

Push Technology
A generic term applied to the methods, products or services used to deliver information to an Internet user, without the user specifically requesting that item of information.

QAM (Quadrature Amplitude Modulation)
A modulation technique, using variations in both signal amplitude and phase to convey information. This technique allows up to 128 data-encoded symbols to be represented per hertz (signal cycle).

QoS (Quality of Service)
A measure of how reliable a carrier’s service is. Usually expressed in terms of availability and measured, as how often available, by .99999 or five nines, which is the top level of reliability.

R&TTE or RTTE (Radio & Telecommunications Terminal Equipment)
Regulatory agency for the European Union. Purpose: Protection of the health (SAR) and the safety of the user. Govern protection requirements with respect to electromagnetic compatibility. Efficient use of the spectrum allocated to space terrestrial/radio communication. redirection

RA (Routing Area)
For purposes of GPRS mobility management the concept of routing area has been added to the basic concepts of GSM. It can be thought of as an IP sub network and is always served by just one SGSN.

Radiation Pattern
The graphical representation of the relative field strength radiated from an antenna in a given plane, plotted against the angular distance from a given reference.

Radiator
A discrete conductor radiating RF energy in an antenna system.

Radio interface
System enabling a mobile terminal to communicate with the network. Numerous discussions were held within ETSI in 1997 on the standardization of a radio interface for UMTS. On 29 January 1998 the SMG committee adopted the UMTS Terrestrial Radio Access standard (UTRA). UTRA was adopted by the ITU in March 1999 as a radio interface standard for IMT 2000.

RADIUS (Remote Authentication Dial-In User Service)
Radius refers to a client/server technique that enables remote access servers (RAS) to communicate with a central server, the Radius server, to authenticate dial-in users and authorize their access to the requested system or service.

Radome
A typically rigid dielectric cover over the radiating portion of an antenna, and nearly always separated from the radiator by an air gap. A radome (the merger of radar and dome) has the purpose of protecting the radiator from natural weather phenomena and contamination by dirt. It usually includes aerodynamic shaping to minimize wind loading.

RAI (Routing Area Identifier)
Each routing area is assigned an identifier (RAI) by the network and is broadcast over the area by the network. A GPRS mobile station monitors the broadcast RAI, and when an RA border has been crossed, it must notify the network that it has moved to a new routing area.

Rake receiver
is the digital section of a CDMA receiver which permits the phone (or cell) to separate out the relevant signal from all the other signals. The relevant signal will be encoded with a known Walsh Code and a known phase of the Short code, and the rake receiver can do this because the Walsh codes are orthogonal and the Short code is orthogonal to itself at different offsets. The rake receiver is capable of receiving multiple signal sources and adding them together using multiple fingers, each of which has the ability to use a separate phase of the short code and long code and a separate Walsh code if necessary. Different fingers might track multiple signals from the same cell (arriving at slightly different times due to multipath) or might track separate cells due to soft handoff.

RAS (Remote Access Server)
A remote access server handles users seeking access to network from a remote or outside location. It may provide gateway/bridge functions between the PSTN or Internet and an enterprise internal network. It also provides authentication services to prevent unauthorized parties from gaining access to the network it serves.

Receiver (Rx)
An electronic device which enables a particular signal to be separated from all and converts the signal format into a format for video, voice or data.

Registration
In CDMA is a process where the phone turns its transmitter on briefly and sends a packet on the paging channel that identifies the phone to the cell system. The phone does this when it first acquires the system. On most systems, it does this periodically (at a time interval selected by the cell system, typically every ten or twenty minutes). The registration message contains part of the phone’s NAM, which the phone system uses to look up the phone’s ESN. (If you are roaming, the roaming system asks your home system to look up the ESN.) The phone also registers if it changes zones, and can be challenged by the system to register.

Relative Antenna Power Gain
The ratio of the average radiation intensity of the test antenna to the average radiation of a reference antenna with all other conditions remaining equal.

Reverse link
In wireless refers to the radio link from the phone to the cell.

RF
Stands for “Radio Frequency” and is a commonly used acronym to refer to a radio link, e.g. “goes over RF to the cell”.

RFDC/RFID
Radio Frequency Data Communications/Radio Frequency Identification.

RI
Ring Indicator

Roaming
1. The ability to move between cells of the same network. 2. The ability to use a cellular phone outside one’s providers’ home service area. Providers often set up Roaming Agreements with other providers in different geographic locations. A roaming agreement lets a caller seamlessly make calls in the other provider’s geographic service area without operator intervention.

Router
A data switch that handles connections between different networks. A router identifies the addresses on data passing through the switch, determines which route the transmission should take and collects data in “packets” which are sent to their destinations. A router is a network resident computer whose job it is to route data traffic to and from other points on the networks to which it has access. It accomplished this through the use of special addressing and routing protocols such as IP.

RSSI (Received Signal Strength Indicator)
Provides a signal for logic circuit processing that is a function of received RF signal strength. RSSI is used both by the switch and the mobile or portable.

RTS
Request To Send

RTT
Radio Transmission Technology. An air interface or standard for mobile phone transmissions.

RUIM application session
Execution of a sequence of commands internal to the RUIM that can result in the performance of one or several proactive RUIM sessions. The RUIM application session can be started by any event in the card session, and can execute for the duration of the card session. Processing of the RUIM application session will not interfere with normal CDMA operation.

S-CDR
A data traffic detail record created by the SGSN, which may subsequently be used for billing purposes.

S-UMTS
Stand for Satellite UMTS. A satellite-based system that, independently of the terrestrial mobile networks and can provide some of the ground based UMTS system’s capabilities.

SAT
Supervisory Audio Tone. One of three tones in 6 KHz region transmitted by the cell site and transponded (returned) by a cellular telephone.

Satellite Mobile Phone
There are various satellite- supported mobile phone networks. The oldest network, “Inmarsat”, requires large terminals. The “Iridium” network developed by Motorola and other companies came out with much smaller terminals, proved to be an economic failure, and is no longer in operation. In principle the ITU specifications for IMT-2000 also provide for optional satellite supply. They would come into question for UMTS supply in sparsely populated areas, deserts, or on the open seas. Because of the poor economic track record of satellite mobile phones to date, however, no concrete steps for satellite use in future UMTS networks are planned.

Satellite network
Network using radio frequencies relayed by satellite.

SAW (Surface Acoustic Wave) filter
A filter that uses surface elastic waves that are transmitted across the surface of a piezoelectric material. This implements a filter that has the resonant frequency and its vicinity as the pass band.

SCADA (Supervisory Control And Data Acquisition)
SCADA systems are used extensively by power, water, gas and other utility companies to monitor and manage distribution facilities. They are also used to monitor and control end user usage levels for purposes such as remote meter reading and load shedding.

SDMA
Space Division Multiple Access, A technique makes it possible to increase the capacity of a cellular mobile radio system by taking advantage of spatial separation between users. The base station does not transmit the signal to the entire cell area, as in conventional access techniques, but concentrates power in the direction of the mobile unit for which the signal is directed, reducing it in the directions where other units are present.

Searching
In CDMA is a process where the phone scans the phase space of the short code looking for valid signals. Depending on when and how this is done, it may be looking for valid pilots, or it may be looking directly for valid paging channels. In a dual-band or dual-mode phone this may also involve attempt to find an AMPS system.

Sector
Refers to the fact that a typical cell divides its circular coverage into several slices, sort of like a pie. The number of sectors supported is variable, but it’s common for there to be three. Each sector in CDMA will use a different PN Offset. From the point of view of the phone, there’s no difference between moving between sectors and moving between cells.

Sectoral Antenna
A directive antenna with a radiation pattern aperture (3 dB beamwidth) larger than 45°. Sectoral antennas are generally used for point-to-multipoint systems or combined with several antennas to create a base station.

Service Data Unit (SDU)
In layered systems, a set of data that is sent by a user of the services of a given layer, and is transmitted to a peer service user semantically unchanged. A Protocol Control Information (PCI) header is attached to the Service Data Unit (SDU) by the layer to form a Protocol Data Unit (PDU).

Service provider
the Company that sends you bills and owns your signature on a contract.

SET(Secure Electronic Transaction)
SET is a system for ensuring the security of financial transactions over the Internet. SET, may authenticate both user and merchant in order to approve the transaction.

SGML (Standardized Generalized Markup Language)
The mother of all markup languages. XML is “SGML light”. HTML is a loose application of SGML.

SGS
Server GPRS Support Nodes.

SGSN (Serving GPRS Support Node)
The Serving GPRS support node or SGSN connects one or more BSCs to the GPRS backbone network, providing IP connectivity to the GGSN on the one hand and converting IP traffic to and from the formats and protocols used by the base station subsystem or BSS.

Shield Effectiveness
A measurement of how well the shielding material (braid, solid tape, etc.) protects the external environment from radiation produced by the center conductor.

Short code
Is a chip sequence that is 215 chips long which repeats every 26.666 milliseconds. Different cells and cell sectors all use the same short code, but use different phases of it, which is how the phone differentiates them from each other. The phase is known as the PN Offset. The moment when the Short code wraps around and begins again is called a PN Roll. (PN stands for Pseudo-Noise.) The chip sequence is designed to be orthogonal to itself at different phases.

SID (System Identification)
A five-digit number that indicates which service area the phone is in. Most carriers have one SID assigned to their service area.

Signal strength
Refers to the total amount of power of RF received by the receiver. This is divided into useful signal, referred to as EC/I0, and the noise floor which is useless.

SIM
Subscriber Identity Module

SIM Card (Subscriber Identity Module)
The Subscriber Identity Module is a subscriber removable printed circuit and chip set card that must be present in GSM phones before they are recognized by a GSM network. The SIM holds information identifying the subscriber to the network. The most recent generation of SIMs are application programmable as well.

SIM Toolkit
A standard for value added wireless services that allows the end-user to establish an interactive exchange with network applications.

Slot cycle
Is a setting that controls the length of a slot. A slot is (1.28 seconds) * (2 ^ slot cycle). So slot cycle 0 is 1.28 seconds, slot cycle 1 is 2.56 seconds, and slot cycle 2 is 5.12 seconds. The longest slot cycle is 7, which is 163.84 seconds. The slot cycle is controlled by the cell. The advantage of a short slot cycle is that it means that the phone gets more chances to receive a page before the call is routed to voice mail. However, this makes the phone use more power, so standby time is not as good. It also means that the paging channel has less capacity. A longer slot cycle provides more capacity on the paging channel and lengthens standby time, but also means that the phone has fewer opportunities to receive a page, so that it’s more likely to miss it and have the call go to voice mail. You as a user cannot choose a slot cycle.

Slotted sleep
Is a mode of phone operation where the phone shuts down nearly all of its electronics most of the time. (All digital phone standards include a form of this. AMPS does not, which is why AMPS battery life is so poor.) The phone wakes on every slot (see slot cycle) to see if it gets paged on the paging channel. Because most of the electronics is turned off most of the time, this uses very little power from the battery. More information about this can be found here.

Smart Antenna
It solve the capacity problems of mature mobile cellular networks. By directing radio signals to an intended target rather than broadcasting throughout the entire cell area, they increase the network’s capacity. The more elaborate smart antenna systems can communicate with multiple mobile stations in the same cell, on the same channel, thereby exploiting their spatial separation.

SMD
Surface Mounted Design

SMS (Short Message Service)
(Short Messaging Service)”Text Messages” is a mechanism that allows brief text messages (up to 160 characters) to be sent to the phone. Several of the major phone standards support it.

Soft handoff
Refers to a feature of CDMA where a phone can communicate simultaneously to two or more cells, or in some cases with two sectors on the same cell. This often happens when the phone is about halfway between the cells or on the dividing line between sectors, and permits the call to continue even though the signal from any one cell would not be strong enough to keep the call up. No other phone standard has this ability. For more on this, browse the AIRSOURCE Knowledgebase, solution # 378.

Software radio
An emerging technology, which allows network operators to simultaneously support multiple communications standards (GSM, CDMA, W-CDMA, 3G etc) on the one network infrastructure without begin bound by a particular standard.

Spectrum
The range of electromagnetic radio frequencies used in the transmission of sound, data and television.

SS7 (Signaling System 7)
SS7 typically employs a dedicated 64-kilobit data circuit to carry packetized machine language messages about each call connected between and among machines of a network to achieve connection control. International equivalent to Bell DNHR. The SS7 protocol consists of 4 basic sub-protocols: 1) Message Transfer Part (MTP), which provides functions for basic routing of signaling messages between signaling points. 2) Signaling Connection Control Part (SCCP), which provides additional routing and management functions for transfer of messages other than call setup between signaling points. 3) Integrated Services Digital Network User Part (ISUP), which provides for transfer of call setup signaling information between signaling points. 4) Transaction Capabilities Application Part (TCAP), which provides for transfer of non-circuit related information between signaling points. Two major capabilities of SS7 are: 1) Fast call setup, via high-speed circuit-switched connections. 2) Transaction capabilities which deal with remote database interactions.

SSL (Secure Sockets Layer)
Protocol for managing the security of message transmissions in a network. The idea is that the programming for keeping your messages confidential ought to be contained in a program layer between an application (such as your Web browser)

Standard Impedance
The nominal impedance associated with the transmission line and test equipment.

Standing Wave Radio (SWR)
See VSWR.

Streaming Media
Technical term for digital audio or video transmissions via the Internet. The sound and image data are sent as a data stream to the subscriber, hence the term “streaming”. A variety of deferred data streams can be output from a streaming media server on the Net. Each receiver can thus receive the same content deferred. Normally, a packet- switched or asymmetric transmission method is used.

Switching
On a telecommunications network, switching means routing traffic by setting up temporary connections between two or more network points. This is done by devices located at different locations on the network, called switches (or exchanges). The basic structure of a telecommunications network therefore comprises transmission media, interconnected by exchanges. “Packet” and “circuit” switching are two techniques used by telecommunications networks. The first is used by IP networks, and the second by traditional networks (PSTN).

Symbian
A joint venture originally set up by Ericsson, Nokia and Psion to develop an industry standard operating system for mobile multimedia terminals (EPOC).

Sync channel
In CDMA is a special channel which is always transmitted by the cell. It is not modulated by the long code. It repeatedly transmits a sync channel message that contains information about the cell and the phone system, and also contains information which permits the phone to determine the absolute wall clock time. The phone looks for the sync channel as the second step of system acquisition, and uses it to synchronize its long code generator. Once the sync channel message has been processed, the phone has sufficient information to begin to process the paging channel and to register.

Synchronous
Type of transmission in which the transmission and reception of all data is synchronized by a common clock and the data is usually transmitted in blocks rather than individual characters. Can also mean that the data stream has the same capacity in both directions.

Synchronous mode
standard for data transmission - data is transferred without start and stop bits together with a clock signal to synchronize the receiver. This mode gives higher data throughput than asynchronous mode, but can be less secure.

TAC
Type Approval Code

TACS (Total Access Communications System)
A short-lived cellular telephone system developed for use in the U.K. TACS is a derivative of AMPS (Advanced Mobile Phone System), the analog cellular standard developed by Motorola and widely deployed in the U.S. and other parts of the world. TACS operated in the 900MHz band, supporting 1,000 voice grade channels. TACS gave way to GSM, which is a muxch better digital technology. JTACS (Japanese TACS), which operated in the 800 and 900MHz rages, suffered a similar fate. See also AMPS and GSM.

TCB (Telecommunications Certification Body)
A TCB is a non-governmental body accredited by ANSI to review applications and issue FCC Certification grants of approval for devices requiring approvals.

TCP
Transmission Control Protocol (TCP) is used to provide reliable data transfer between two IP endpoints but is not as fast as UDP.

TCP/IP
Transmission Control Protocol (TCP), and Internet Protocol (IP) together define the basic rules for how information is transmitted across the Internet (as well as on most LANs) in packetized form.

TD-SCDMA
Siemens developed this special transmission method for UMTS together with the China Academy of Telecommunications Technology (CATT). TD-SCDMA is to be used for setting up UMTS mobile phone networks in China. It combines the SCDMA technique developed by CATT with the TD-CDMA method proposed by Siemens and other manufacturers. The S in ‘SCDMA’ refers to the special synchronous mode: All radio base stations transmit and receive synchronously: they prevent unavoidably occurring feedback interferences with asynchronous radio methods. An advantage of the TD-SCDMA technique is that it is also suitable for unpaired frequency ranges (frequencies, duplex separation).

TDD
Time Division Duplex. This will be the second variation of W-CDMA, which will be standardized towards the end of 2001, to appear commercially towards the end of 2003. This version is especially suited to indoor environments where there is a need for high traffic density.

TDMA (ANSI-136)
“TDMA” has been adopted as the new name for the “Digital AMPS” (D-AMPS) mobile standard, now called ANSI-136, used in the Americas, Asia Pacific and other areas. TDMA services can be delivered in the 800 MHz and 1900 MHz frequency bands.

TDMA (Time Division Multiple Access)
TDMA is a communications technique whereby multiple users can share a physical radio channel by being assigned specific, rotating time slots for transmitting and receiving. TDMA is also used sometimes to refer specifically to the standard covered by IS-136, which is a source of confusion because GSM also uses a TDMA air interface, as does IDEN, and neither of those systems are compatible with IS-136.

TDOA
Time Difference of Arrival. One of the simpler network-based methods, TDOA uses the time it takes for a signal to travel as an indirect method of calculating distance. With a minimum of three base stations receiving a signal from a handset, triangulation can determine the position of the MS. To achieve accurate positioning, the base stations must be precisely synchronized in time, which is usually done by GPS. Accuracy: 100-200m.

TE
Terminal Equipment

Telematics
A generic term for a wireless network supporting the collection and dissemination of data. Static, or fixed applications including SCADA (Supervisory Control And Data Acquisition), which is used in the power utility industry for meter reading and load control. Mobile applications include vehicle tracking and positioning, on-line navigation, and emergency assistance.

Terminal
A terminal can be a notebook computer, PC, TV, phone, mobile device, appliance etc.

TIA (Telecommunications Industry Association)
The Telecommunications Industry Association (TIA) is the leading U.S. non-profit trade association serving the communications and information technology industry, with proven strengths in market development, trade shows, domestic and international advocacy, standards development and enabling e-business. Through its worldwide activities, the association facilitates business development opportunities and a competitive market environment. TIA provides a market-focused forum for its member companies, which manufacture or supply the products and services used in global communications. Telecommunications Industry Association (TIA)

TID (Tunnel ID)
Packets traveling along the GPRS backbone are ‘wrapped’ inside an additional addressing layer to form GTP packets. Each GTP carries a TID or Tunneling identifier which tells the SGSN and GGSN whose IP packet is contained inside. In affect it associates the IP address of the packet with the ISMI.

Tier 1
Tier I is the initial support provided to both educate the customer and help guide the customer to the most effective solution selection. All Tier I support is provided from publicly published documents and procedures provided by AIRDESK’s vendors as well as AIRDESK itself. The customer can browse the AIRDESK support site for documents and request assistance via the web interface.

Tier II
Tier II technical support provides the tools and knowledge for the integrator and developer to bring their project to completion. Advanced industry knowledge is brought to the customer’s fingertips with direct access to the AIRDESK’s knowledgebase as well as access to the Technical Support team at AIRDESK. The knowledgebase includes all documented issues and their solutions provided both by the manufacturers as well as AIRDESK in a searchable web based database. AIRDESK personnel will be available to work through issues using the SDK/MDK/MSK’s and starter kits. Escalations transferred to Tier III.

Tier III
Takes on escalations as required from Tier II. Tier III Technical Support involves all non-documented issues and solutions. Engineering resources both at the manufacturer and at AIRDESK will be employed to bring the issue to resolution. AIRDESK will requires clear documented issues from the customer so that AIRDESK may engage the issue with the engineers it deems necessary. AIRDESK acts as the customer’s liaison to the manufacturer. The customer will need to clearly document the outstanding issue(s), and work with both AIRDESK directly and the manufacturers indirectly to resolve the issue. Communication may include Email, web interface as well as phone conversations for all parties involved.

TLV
Tag, length, value

TOA
Time of Arrival. Similar to the TDOA technique, this technology only differs in that it uses the absolute time of arrival at a certain BTS rather than the difference between two stations. Three BTSs are required to resolve the precise position of a MS. Synchronization of the network base stations is important. Accuracy: 100-200m.

Traffic channel
Is a channel which carries a phone call. When a phone wants to set up a call, it makes a request to the cell on the paging channel and the cell system sends back a message telling it which traffic channel to use (in other words, which Walsh Code to use).

Transmission Line
The connecting link, which allows the radio frequency energy generated by the transceiver to be delivered to the antenna. (Coaxial Cable, microstrip or coplanar lines in our industry.)

Transmitter
An electronic device consisting of oscillator, modulator and other circuits that produce a radio electromagnetic wave signal for radiation into the atmosphere by an antenna.

TRI-BAND
A phone which can operate on three bands, typically a GSM phone operating on 900 MHz, 1800 MHz, and 1900 MHz.

Triple-band (Tri-Band)
It means phone understand the American 1900MHz frequency band as well as the European 900MHz and 1800MHz.

TTA
Telecommunications Technology Association of Korea. The purpose of TTA is to contribute to the advancement of technology and the promotion of information and telecommunications services and industry as well as the development of national economy, by effectively establishing and providing technical standards that reflect the latest domestic and international technological advances, needed for the planning, design and operation of global end-to-end telecommunications and related information services, in close collaboration with companies, organizations and groups concerned with information and telecommunications such as network operators, service providers, equipment manufacturers, academia, R&D institutes, etc. ?????????? ????

TTS (Text-to-Speech)
The flip side of speech recognition, TTS takes written words and converts them to speech. Thus, when a caller requests specific information from a voice portal, such as driving directions, TTS reads the directions to the caller. Early TTS efforts were slow and were usually read by a computerized voice that was often referred to as “Igor” because of its similarity to the voice of the character of the same name in old horror movies. Current TTS technology is much more natural sounding, and in some situations the caller would be challenged to differentiate TTS from an actual human speaker.

UA
User Agent. Software that interprets WML, WMLScript, WTAI and other forms of code. Explorer, Netscape and Opera, are examples of UA’s)

UDP (User Datagram Protocol)
User Datagram Protocol is used to provide fast data transfer between two IP endpoints, but is not as reliable a method as TCP.

UE
User Equipment

UICC
USIM Integrated Circuit Card. The UICC is the chip card used in mobile terminals in 3G telecom networks-Systems. The UICC is an essential component for UMTS, just as the SIM is for GSM. Extending the concept of the SIM card, the UICC contains the USIM application and also provides a platform for other IC Card applications. It ensures the integrity and security of all kinds of personal data, enabling secure support for all kinds of multi-application schemes.

UIM
SIM card equivalent planned for W-CDMA handsets.

UMTS (Universal Mobile Telecommunications System)
This is almost universally subscribed to standard for the third generation and is generally based on W-CDMA (Wideband Code Division Multiple Access). UMTS will launch in 2002, but full services for the general public will not arrive until around 2005. It promises a permanent internet connection of at least 384kbps and up to about 2mbps, combined with highly integrated devices and a super-fast back end.

Uplink
Most data-communication connections are bi-directional. The direction toward the remote user is referred to as the “downlink”. The direction away from the remote user is referred as the “uplink”.

URL
The Universal Resource Locator is used to give Web addresses for HTML, VRML, WAV and other files. It simply contains the Internet address of the machine containing the data and the directory path to the file. The URL may also include information on what access methods to use.

UTK
Set of applications and related procedures that may be used during a card session.

UTRA
UMTS Terrestrial Radio Access. A term use for UMTS radio access solution, applied to W-CDMA and TD-CDMA.

UTRAN
UMTS Terrestrial Radio Access Network. A term describing the Radio Network Controllers and Node Base stations of a UMTS network. The UMTS network, built around an IP-optimized core network carrying all traffic types. UTRAN will support both UTRA Frequency Division Duplex (FDD) and Time Division Duplex (TDD) radio interfaces allowing flexible, high-bandwidth support, and will be connected to an IP-optimized core network through a UTRAN Gateway.

UWC-136
Universal Wireless Communications 136. Proposed by the TIA and adopted by the ITU for 3G, UWC-136 is a 3G TDMA standard that allows the US TDMA community to migrate from 1st (IS-136) to 3rd (UWC-136) generation systems. The standard uses a wideband TDMA technique.

VOD
Video On Demand. A service that allows subscribers to watch programs at the time when they want

VoIP
Voice over Internet Protocol - VoIP is not simply for voice over IP, but is designed to accommodate two-way video conferencing and application sharing as well. Based on IP technology, VoIP is used to transfer a wide range of different type traffic.

VOIP (Voice Over Internet Protocol)
Describes the process of transmitting voice via data IP packages.

Voltage Standing Wave Ratio (VSWR)
VSWR of the antenna is the ratio of the maximum to minimum values of voltage in the standing wave pattern appearing along a lossless 50 Ohms transmission line with an antenna as the load.

VPN (Virtual Private Network)
A virtual private network (VPN) is a private data network that makes use of the public telecommunication infrastructure, maintaining privacy through the use of a tunneling protocol and security procedures. A virtual private network can be contrasted with a system of owned or leased lines that can only be used by one company. The idea of the VPN is to give the company the same capabilities at much lower cost by using the shared public infrastructure rather than a private one (expensive dedicated/leased lines).

VSWR (Voltage Standing Wave Ratio)
The ratio of the maximum effect voltage measured along the length of a mismatched radio frequency transmission line. Explanation: When impedance mismatches exist, some of the energy will be reflected back to the source. Different amounts of energy will be reflected back depending on the frequency of the energy. VSWR is a unitless ration from 1 to infinity, expressing the amount of reflected energy. A value of one indicates that all of the energy will pass through, while any high value indicates that a portion of the energy will be reflected.