Robert Katz
Cooperative multitasking - A method of running more than one program on a computer at a time in which the program currently in control of the processor retains the control until it yields the control to another program voluntarily, which it can do only at certain points in the program.

Preemptive multitasking allows the computer system to more reliably guarantee each process a regular "slice" of operating time. It also allows the system to rapidly deal with important external events like incoming data, which might require the immediate attention of one or another process.

threads- A portion of a program that can run independently of and concurrently with other portions of the program.



Wave propagation is any of the ways in which waves travel

Attenuation is a general term that refers to any reduction in the strength of a signal
Signal reflection occurs when a signal is transmitted along a transmission medium, such as a copper cable or an optical fiber, some of the signal power may be reflected back to its origin rather than being carried all the way along the cable to the far end.

Noise is any undesired signal in a communication circuit(thermal noise, intermodulation noise, crosstalk and impulse noise.)

Dispersion is the dependence of wave velocity on frequency or wavelength

Jitter is the undesired deviation from true periodicity of an assumed periodic signal in electronics and telecommunications, often in relation to a reference clock source.

Latency is a measure of the time delay experienced by a system

Collision is the situation that occurs when two or more demands are made simultaneously on equipment that can handle only one at any given instant.


A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data.


multidimensional parity-check code (MDPC) is a simple type of error correcting code that operates by arranging the message into a multidimensional grid, and calculating a parity digit for each row and column.

Multimode fiber optic cable has a large-diameter core that is much larger than the wavelength of light transmitted, and therefore has multiple pathways of light-several wavelengths of light are used in the fiber core.

Singlemode fiber optic cable has a small core and only one pathway of light. With only a single wavelength of light passing through its core, singlemode realigns the light toward the center of the core instead of simply bouncing it off the edge of the core as with multimode.


light is measured in nanometers

Visible light has wavelength in a range from about 380 nanometres to about 740 nanometres