1. The attribute of an optical fiber, the cross section of the core or cladding of which deviates from a perfect circle.
2. In an optical fiber, the degree of deviation, from perfect circularity, of the cross section of the core or cladding.
Note 1: The cross sections of the core and cladding are assumed to first approximation to be… (Read More →)

Operator Virtual Connections

Providing electronic key via over-the-air rekeying, over-the-air key transfer, or cooperative key generation. [INFOSEC-99]

Electronically distributing key without changing traffic encryption key used on the secured communications path over which the transfer is accomplished. [INFOSEC-99]

Changing traffic encryption key or transmission security key in remote crypto -equipment by sending new key directly to the remote crypto-equipment over the communication path it secures. [INFOSEC-99]

A radar system that makes use of the atmospheric reflection and refraction phenomena to extend its range of detection beyond line of sight. Over-the-horizon radars may be either forward scatter or backscatter systems. [JP 1-02]

1. The condition that prevails when the numerical aperture of an optical source, such as a laser, light-emitting diode, or optical fiber, exceeds that of the driven element, e.g., optical fiber core.
2. The condition that prevails when the beam diameter of an optical source, such as a laser, light-emitting diode, or optical fiber, exceeds that of the driven element,… (Read More →)

1. In telephony, the generation of potential traffic that exceeds the capacity of a communications system or subsystem.
2. In telephony, a count of telephone call attempts made on groups of busy trunks or access lines.
3. In telephony, traffic handled by overflow equipment.
4. In telephony, traffic that exceeds the capacity of the switching equipment and is therefore lost.… (Read More →)

Any bit other than a user information bit.

See overhead bit.