Communication Definitions

"A" to :Asc",
"Asy" to "Bc",
"Be" to "Bi",

"Bl" to "Cz",
"D" to "E",
"F" to "L",

"M" to "Mod",
"Mu" to "Nu",
"O" to "Z"

**B8ZS:** Abbreviation for bipolar with eight-zero
substitution. A T-carrier line code in which bipolar
violations are deliberately inserted if user data
contains a string of 8 or more consecutive zeros.
B8ZS is used to ensure a sufficient number
of transitions to maintain system synchronization
when the user data stream contains an insufficient
number of ones to do so. B8ZS is used in
the European hierarchy at the T1 rate.

**BER:** Abbreviation for bit error ratio.

**Binary-Coded Decimal (BCD):** Pertaining to the representation of a decimal digit by a unique
arrangement of no fewer than four binary digits.

**Binary Modulation:** The process of varying a
parameter of a carrier as a function of two finite, discrete states.

**Bipolar Signal:** A signal that may assume either of
two polarities, neither of which is zero. A bipolar signal may have a two-state non-
return-to-zero (NRZ) or a three-state return-to-zero
(RZ) binary coding scheme. A bipolar
signal is usually symmetrical with respect to zero
amplitude, i.e., the absolute values of the positive
and negative signal states are nominally equal.

**Bit Error Ratio (BER):** The number of erroneous bits
divided by the total number of bits transmitted, received or processed over some stipulated period. Note 1: Examples of bit error ratio are (a) transmission BER, i.e, the number of erroneous bits
received divided by the total number of bits
transmitted; and (b) information BER, i.e., the
number of erroneous decoded (corrected) bits
divided by the total number of decoded (corrected)
bits. Note 2: The BER is usually expressed as a coefficient and power of 10; for example, 2.5 erroneous bits out of 100,000 bits transmitted would
be 2.5 out of 105 or 2.5 x 10-5.

**Bit Rate (BR):** In a bit stream, the number of bits
occurring per unit time, usually expressed in bits per
second. Note: For n-ary operation, the bit
rate is equal to log n times the rate (in baud), where 2
n is the number of significant conditions in the
signal.

**Bits per second:** [b/s] A unit used to express the
number of bits passing a designated point per
second. Note 1: For example, for two-condition
serial transmission in a single channel in
which each significant condition represents a bit, i.e.,
a 0 or a 1, the bit rate in bits per second and the baud
have the same numerical value only if each bit
occurs in a unit interval. In this case, the data
signaling rate in bits per second is 1/T, where T is
the unit interval. The abbreviation bps is
not in accordance with international standards, and
is deprecated.

**Bit Slip:** In digital transmission, the loss of a bit or
bits, caused by variations in the respective clock
rates of the transmitting and receiving devices.
Note: One cause of bit slippage is overflow of a
receive buffer that occurs when the transmitters
clock rate exceeds that of the receiver. This causes
one or more bits to be dropped for lack of storage
capacity.

**Bit synchronous operation:** Operation in which data
circuit terminating equipment (DCE), data terminal
equipment (DTE), and transmitting circuits are all
operated in bit synchronism with a clock. In bit synchronous operation, clock timing is usually
delivered at twice the modulation rate, and one bit is
transmitted or received during each clock cycle. Bit synchronous operation is sometimes
erroneously referred to as digital synchronization.