Wireless Glossary – A

Aggregate MAC Service Data Unit

Additional Spectrum Emission Mask specifes additional spectral emission constraints for particular deployment. UE is instructed when it has to apply an A-SEM by signaling from the network.

Authorization, Authentication and Accounting, processes involve establishing a terminal’s identity, configuring authorizations to access particular types of service, and monitoring traffic volumes for each user.

Asynchronous Balanced Mode of packet data transfer, used by the Logical Link Control layer for acknowledged bidirectional communication between a mobile base station and a Serving GPRS Support Node, which includes error recovery and provides in-sequence delivery. ABM implies that the station at either end of the link has the right to set-up, reset, or disconnect a link at any time.

Aggregate Base Station Quality of Service Profile. Defines the Quality of Service (QoS) profile for a Base Station Subsystem (BSS) packet flow content.

A router located between several areas in a hierarchical OSPF network. These routers’ function are to summarize subnets to the rest of the OSPF autonomous system. These routers must maintain topology information from multiple areas, and are therefore typically robust in resources.

The FCC was established by the Communications Act of 1934 as the successor to the Federal Radio Commission and is charged with regulating all non-Federal Government use of the radio spectrum (including radio and television broadcasting), and all interstate telecommunications (wire, satellite and cable) as well as all international communications that originate or terminate in the United States. The FCC took over wire communication regulation from the Interstate Commerce Commission. The FCC’s jurisdiction covers the 50 states, the District of Columbia, and U.S. possessions.

Weakening (loss) of radiation when it passes through a material (part of the radiant energy of light, for example, is converted into heat).

A wireless LAN transceiver that acts as a center point and bridges between wireless and wired networks.

Two to six Access Point Modules that together distribute network or Internet services to a community of 1,200 or fewer subscribers. Each Access Point Module covers a 60° sector. This cluster covers as much as 360°. Also known as AP cluster.

Typically to provide connectivity between end devices, this is a switch port with one VLAN assigned to it.

This command functions to apply an access list to vty ports.

Adjacent Channel Interference is interference caused by extraneous power from a signal in an adjacent channel.

Adjacent Channel Interference Ratio of the total power transmitted from a source to the total interference power affecting a receiver, resulting from both receiver and transmitter imperfections, a function of the Adjacent Channel Leakage Ratio (ACLR) and the Adjacent Channel Selectivity (ACS).

ACKnowledgement

Acknowledgment, a signal transmitted to indicate that one or more blocks of data have been successfully received and decoded, used in Hybrid Automatic Repeat reQuest (HARQ) and in Radio Link Control (RLC) level ARQ.

Adjacent Channel Leakage Ratio, a measure of the power which leaks into specific nearby Radio Frequency (RF) channels as a result of transmitting in a given channel. It delivers an estimate of how much a neighboring radio receiver will be affected by the Out Of Band (OOB) emissions from a transmitter.

Adjacent Channel Rejection Ratio of the Root Raised Cosine (RRC) weighted gain per carrier of the repeater in the pass band to the RRC weighted gain of a repeater on an adjacent channel.

Adjacent Channel Selectivity, a measure of a receiver’s ability to receive a wanted signal at its assigned channel frequency in the presence of an adjacent channel interfering signal at a given frequency offset from the center frequency of the assigned channel, without the interfering signal causing a degradation of the receiver performance beyond a specified limit.

To provide feature capability to a module, but not to enable (turn on) the feature in the module. See also Enable.

A wireless network composed only of stations without access points. Peer-to-peer

A mechanical media termination device designed to align and join fiber optic connectors. Often referred to as a coupling, bulkhead or interconnect sleeve.

Advanced Element Panel Technology

Asynchronous Disconnected Mode of packet data transfer used by the Logical Link Control layer for unacknowledged communication between a mobile base station and a Serving GPRS Support Node, without prior establishment of a logical connection.

Asymmetric Digital Subscriber Line providing high-speed data transmission over conventional twisted-pair copper telephone lines, by frequency-division multiplexing with analogue voice traffic. Download speeds are higher than upload speeds.

Advanced Encryption Standard.

Managed by NIST of the U.S. government, this is the newest encryption algorithm. AES today offers 128-, 192-, and 256-bit encryption, and serves to increase encryption strength beyond the DES and 3DES standards and provide more efficiency for the device’s processor.

The sum of the throughputs in the uplink and the downlink.

Above Ground Level

Arbitration Interface Space Number

The system for encoding radio signals in a wireless network such as TDMA, CDMA, AMPS.

Authentication and Key Agreement is the process by which the Authentication Centre and UE exchange information by which they can verify a secret key held by the other, and then calculate keys for ciphering and integrity protection of data transmitted between the UE and the network.

Access Link Control Application Protocol, name for the signaling protocols used to setup and tear-down transport bearers.

In electricity, alternating current (AC) occurs when charge carriers in a conductor or semiconductor periodically reverse their direction of movement.

Acknowledged Mode is one of 3 Radio Link Control modes (the other two Transparent Mode and Unacknowledged Mode). Includes Automatic Repeat reQuest (ARQ) for error-free packet delivery.

Aggregated Maximum Bit-Rate, the upper limit on the aggregate bit rate that can be expected to be provided across all non-Guaranteed Bit Rate bearers.

Adaptive Modulation and Coding, a form of link adaptation which adjusts the transmitted information data rate by varying the modulation order and the Forward Error Correction (FEC) code rate.

Acknowledged Mode Data is the type of Protocol Data Unit (PDU) used to carry user data in Radio Link Control (RLC) Acknowledged Mode (AM).

An electronic device that increases the voltage, current, or power of a signal.

Adaptive Multi-Rate, a type of source coding, often used for digital speech transmission, whereby the bit rate of the generated data stream is adapted by the encoded quality of the signal.

Above Mean Sea Level

An analog signal is one in which a base carrier’s alternating current frequency is modified in some way, such as by amplifying the strength of the signal or varying the frequency, in order to add information to the signal.

Automatic Neighbor Relation, a function by which eNodes can automatically determine what cells are their neighbors.

That part of a transmitting or receiving system which is designed to radiate or to receive electromagnetic waves”. An antenna can also be viewed as a transitional structure (transducer) between free-space and a transmission line (such as a coaxial line). An important property of an antenna is the ability to focus and shape the radiated power in space e.g.: it enhances the power in some wanted directions and suppresses the power in other directions.

Antenna beamwidth is the peak-to-peak angle overlaying the maximum gain beam of the antenna at which its gain is reduced by 3 dB. Contrary to popular belief, the 3 dB gain beam-width of an antenna does not represent its interference beam-width, which is significantly wider. For example, a typical 2-foot parabolic antenna at 5.8 GHz has 28 dBi of gain, and a typical beam-width of 6 degrees. However, as an interference source, it radiates with 25 dBi of gain over a 6 degree area, 10 dBi of gain over a 32 degree area, and 2 dBi gain over a 170 degree area.

Antenna gain is the amount of increase in signal strength (in decibels) that results from an antenna concentrating its radiated signal into a given direction, when compared to the gain of a reference antenna. As antenna gain increases in a given direction, its radiated “beam-width” becomes narrower in one or more aspects.

“In a specified direction from an antenna and at a point in its far field, is the polarization of the (locally) plane wave which is used to represent the radiated wave at that point”. “At any point in the far-field of an antenna the radiated wave can be represented by a plane wave whose electric field strength is the same as that of the wave and whose direction of propagation is in the radial direction from the antenna. As the radial distance approaches infinity, the radius of curvature of the radiated wave’s phase front also approaches infinity and thus in any specified direction the wave appears locally a plane wave”. In practice, polarization of the radiated energy varies with the direction from the center of the antenna so that different parts of the pattern and different side lobes sometimes have different polarization. The polarization of a radiated wave can be linear or elliptical (with circular being a special case).

Application Protocol is a part of the Control-plane of E-UTRAN and operate across the S1 and X2 interfaces.

Access Point Authentication Server. Licensed to authenticate SMs that attempt to register to it. The AP licensed as APAS may or may not have authentication enabled (turned on). See also Activate and Enable.

Access Point Name, defines a Gateway GPRS Support Node (GGSN) or Packet Data Network GateWay (PGW). Includes APN network identifier which defines the Packet Data Network (PDN) to which the UE requests connectivity, and may also include APN operator ID which defined in which Public Land Mobile Network (PLMN) the P-GW or GGSN is located.

OSI model, Layer 7. This layer offers an interface between a host’s communication software and any external applications (such as email, file transfers, and terminal emulation). This layer can also decide on the resources needed to communicate between two devices and verify their availability.

Management Information Base file that defines objects that are specific to the Access Point Module or Backhaul timing master.

Protective element (usually steel wire or tape) used on cables with special operational requirements e.g. direct burial, undersea, in mines and for rodent protection.

Allocation and Retention Priority is a parameter of the Quality of Service (QoS) profile of an Evolved Packet System (EPS).

A protocol that sends a broadcast ARP in order to map a known IP address to a MAC address. If the target IP address is on another sub-net, the sender broadcasts ARP for the router’s Ethernet port or default gateway, so the MAC address sent back is that of the router’s Ethernet port.

Automatic Repeat reQuest is a scheme whereby the receiver requests retransmission of packets which are detected to be erroneous. Used in Radio Link Control (RLC) Acknowledged Mode (AM), as well as being a component of Hybrid ARQ (HARQ).

Access Security Management Entity which receives the top-level keys in an access network from the Home Subscriber Server (HSS).

Asymmetric networks support more bandwidth in one direction than the other. Asymmetric DSL offers more bandwidth for customer downloads at the cost of less bandwidth for uploads.

A packet-switched connection type which achieves high speeds by dividing all packets into equal-sized 53-byte cells.

Automatic Transmitter Power Control

Describes how a signal loses strength over long distances.

A feature used to reduce fraud by confirming the identity of a phone to the wireless network.

Software key that correlates to the random number that the Bandwidth and Authentication Manager (BAM) server generates and sends in a challenge through the AP to the SM. The network operator can create and, at some security risk, send this key over the air to the SM. The SQL database in the BAM server correlates this key to QoS information about the SM. The format of this key is 32 hexadecimal characters of 0 to 9 and a to f, padded with leading zeroes in Release 4.2.3 and later. This key must be unique to the individual SM.

A signaling method that lets each node define its operational mode and detect the operational mode of the adjacent node. Auto-negotiation can be used in dual-function 10/100 Mbps Ethernet adapters. The process happens out-of-band with no loss of network throughput.

This out-of-band management connection is used to link an external modem with a rollover cable.

Azimuth and elevation are angles used to define the apparent position of an object in the sky, relative to a specific observation point. The observer is usually (but not necessarily) located on the earth’s surface. The azimuth (az) angle is the compass bearing, relative to true (geographic) north, of a point on the horizon directly beneath an observed object. As seen from above the observer, compass bearings are measured clockwise in degrees from north. Azimuth angles can thus range from 0 degrees (north) through 90 (east), 180 (south), 270 (west), and up to 360 (north again). The elevation (el) angle, also called the altitude, of an observed object is determined by first finding the compass bearing on the horizon relative to true north, and then measuring the angle between that point and the object, from the reference frame of the observer. Elevation angles for objects above the horizon range from 0 (on the horizon) up to 90 degrees (at the zenith).