Answer and Explanation:
Communication is possible when sender and reciever both communicates in well manner and communication is only possible when there is a sender available to communicate.
1) Sending data from A to B, there is no possible communication between A and other stations because while A is communicating with B the packet's of station A will interfere with other packets by other stations. Thus while transmission from A to B there is no other communication possible between any other station.
2) In this case also there is no communication possible as B can communicate with other stations except D. If E and C try to send some data to D at the same time then this would interfere B's transmission to A. Thus while transmission from B to A there is no communication possible between any other station.
3) Station B can communicate with E, A and C but not with D. while sending data from B to C the communication will be interfered by the station B's transmission to A. But station E can safely transmit data to D while communication between station B to C. Thus there is one communication possible while sending data from B to C which is E to D.
Solution to 1. When A is sending to B, then communication is established within A,C,E.
Solution to 2. When B is sending to A, A can communicate with other stations and in this case ,there is a possibility of communication with C,D,E as B is sending to A.
Solution to 3. When B is sending to C, communication is established between A,B and D.
