Blockage:

• There are two types of blockage

• Set up blockage: To a mobile several calls can inter-collide simultaneously. If this no exceeds 10 then mobile is said to be blocked and this blockage is called as setup channel blockage.

Voice channel blockage: simultaneously when many calls come in , calls are rejected because there are no voice channels available, this is called voice channel blockage.

Word error rate: Word error rate (WER) is a common metric of the performance of a speech recognition translation system.

word error rate can then be computed as WER = S+D+I/N

s is the number of substitutions, D is the number of deletions, I is the number of insertions, c is the number of the corrects, N is the number of words in the reference )N=S=D=C)

Voice quality: voice quality is signal to ration and distortion ration. SINAD is usually expressed in dB and is quoted alongside the receiver RF sensitivity, to give a quantitative evaluation of the receiver sensitivity.