Also known as Project Codes or Bill-Back Codes. Account Codes
are additional digits dialed by the calling party that provide
information about the call. Typically used by hourly professionals
(accountants, lawyers, etc.) to track and bill clients, projects,
etc.
A 32-bit long mask used to select an IP address for subnet
addressing. The mask selects the network portion of the IP address and
one or more bits of the local LAN address.
The process of converting external addresses into standardized
network addresses and vice versa. Facilities interconnection of multiple
networks which each have their own address plan.
ADSL is a technology
that allows data to be sent at rates as high as 6 Mbps through
the conventional (analog, copper) telephone line, and is considered
one of the most promising ways of connecting the "Information
Superhighway" to the home. In collaboration with Aware, Inc.
of Cambridge, Analog Devices has developed systems that support
this standard.
Local exchange carriers in direct competition with the RBOCs.
Normally found only in the larger metropolitan areas. Examples are
Teleport and Metropolitan Fiber Systems.
A line code used for T-1 and E-1 lines that has a 12.5% ones
density minimum, and the one conditions of the signal alternate between
positive and negative polarity.
Amplitude Modulation; the simplest carrier modulation technique where the RF carrier's envelope
is modulated -- used today by broadcast band (BC) stations.
Stands for Advanced Mobile Phone System, which is the most common type of First
Generation analog cell phone network. Because analog phones
are suited for voice rather than data communications, AMPS networks are rapidly
being supplanted by digital wireless networks. Operates in the 800 MHz frequency
band and uses FDMA technology.
A line code used for T-1 and E-1 lines that has a 12.5% ones
density minimum, and the one conditions of the signal alternate between
positive and negative polarity.
A position identification technology that detects the direction of a signal received
from a transmitter at only one point. In this system, the transmitter's location
is determined from the receivers' antenna position and the AOA of the signals that
are from the antennas.
The specifications of a system and how its subcomponents
interconnect, interact and cooperate. Architectures are often
described in multiple levels of abstraction from low-level physical
to higher-level logical application and end-user views.
Used to dynamically bind a high level IP address to a low-level
physical hardware address. ARP is limited to a single physical network
that supports hardware broadcasting.
A form of concurrent input and output communication transmission
with no timing relationship between the two signals. Slower-speed
asynchronous transmission requires start and stop bits to avoid a
dependency on timing clocks (10 bits to send on 8-bit byte). (Contrast
with Synchronous)
An international ISDN high-speed,
high-volume, packet-switching transmission protocol standard. ATM uses
short, uniform, 53-byte cells to divide data into efficient, manageable
packets for ultrafast switching through a high-performance
communications network. The 53-byte cells contain 5-byte destination
address headers and 48 data bytes. ATM is the first packet-switched
technology designed from the ground up to support integrated voice,
video, and data communication applications. It is well-suited to
high-speed WAN transmission bursts. ATM
currently accommodates transmission speeds from 64 Kbps to 622 Mbps. ATM
may support gigabit speeds in the future.
These three types of high-speed fiber-optic systems (ATM switch interface, SONET/SDH
network) are being deployed now in
the LAN/WAN environment to connect workstations and to transport
high bit-rate services.
A loss of signal strength in a lightwave, electrical or radio
signal usually related to the distance the signal must travel (e.g.
fiber optic transmission must be regenerated approx. every 30
miles). Fiber optic attenuation is caused by transparency of the
fiber, bending the fiber at too small of a radius, nicks in the
fiber, splices, poor fiber terminals, FOTs, etc. Electrical
attenuation is caused by the resistance of the conductor, poor
(corroded) connections, poor shielding, induction, RFI, etc.
Radio signal attenuation may be due to atmospheric conditions, sun spots, antenna
design / positioning, obstacles, etc.
A measure of the similarity between a signal and a time-shifted replica of itself; a
special case of cross-correlation; The auto-correlation function is the theoretical basis of
direct sequence spread spectrum.
Originating Number (1) The number associated with the
telephone station(s) from which switched calls are originated (or
terminated). (2) A software feature associated with Feature Group D
(and optional on Feature Group B) circuits. ANI provides the
originating local telephone number of the calling party. This
information is transmitted as part of the digit stream in the
signalling protocol, and included in the Call Detail Record for
billing purposes. (3) ANI may also be used to refer to any phone
number.
A private line connecting a station instrument in one location to a
station instrument in a distant location with automatic two-way
signaling. The automatic two-way signaling used on these circuits
causes the station instrument on one end of the circuit to ring when the
station instrument on the other end goes off-hook. This circuit is
sometimes called a "hot-line" because urgent communications are
typically associated with this service. ARD circuits are commonly used
in the financial industry. May also have one way signaling. Station
"A" rings Station "B" when Station "A"
goes off hook, but Station "B"
cannot ring Station "A".
