Andrew S. Tanenbaum Edition 5 Exercise 4 Question 10 (Page No. 351)

Question

Consider five wireless stations, A, B, C, D, and E. Station A can communicate with all
other stations. B can communicate with A, C and E. C can communicate with A, B and
D. D can communicate with A, C and E. E can communicate A, D and B.
(a) When A is sending to B, what other communications are possible?
(b) When B is sending to A, what other communications are possible?
(c) When B is sending to C, what other communications are possible?

Answer 1

(a) Since all stations will see A’s packet, it will interfere with receipt of any other packet by any other station. So, no other communication is possible in this case.

(b) B's packet will be seen by E, A and C, by not by D. Thus, E can send to D, or A can send to D, or C can send to D at the same time.

(c) This scenario is same as (b).