Propagation delay
Propagation delay is the time duration taken for a signal to reach its destination, for example in the electromagnetic field, a wire, gas, fluid or solid body. == Physics == An electromagnetic wave travelling through a medium has a propagation delay determined by the speed of light in that particular medium, or ca.(circa/approx) 1 nanosecond per 29.98 centimetres (11.80 in) in a vacuum.