Question

A pure ALOHA network transmits 200-bit frames on a shared channel of 200 kbps. What is the throughput if the system (all stations together) produces 1000 frames per second?

(a) 150 frames

(b) 80 frames

(c) 135 frames

(d) 96 frames

I got this question by my college professor while I was bunking the class.

Question is from Layers in section Cryptography Overview, TCP/IP and Communication Networks of Cryptograph & Network Security

Answer 1

Correct answer is (c) 135 frames

To elaborate: Frame transmission time

Tfr= 200/200 kbps or 1 ms.

If the system creates 1000 frames per second, or 1 frame

per millisecond, then G = 1

S = G × e−2G = 0.135 (13.5 percent)

This means that,

Throughput =1000 × 0.135 = 135 frames.