#3

In the Contention-free Period, the Ap sends Contention-Free-Poll CE-Poll) bas station, one at a time, to give them the right to send a paeket. The Interframe spad technology to control the packet sending. Please draw the PCY frame transfer accor following example. (0) There are 4 packets in AP. H1 contains a packet, and H4 contains a paeket. paekets to each ace is a AP Data H2 Data H3 Data:H4 Data H5 Hi Data AF H1 Data H2 no Data H3no Data H4 Data A HS no Data 3 [How can one mobile station send a message to a sleeping mobile station in a Multi-hop Ad Hoc network? (15) 4 CSMA/CA can solve the Hidden terminal problem, but cannot solve the Exposed ter problem, why? (15)