urgent help

2 In the Contention-free Period, the AP sends Contention-Free-Poll (CF-Poll) packets to each station, one at a time, to give them the right to send a-packet. The Interframe Space is a key technology to control the packet sending. Please draw the PCF frame transfer according to the following example. (24) There are 5 packets in AP. H1 contains a packet, H2 contains a packet, H3 contains a packet and H3 contains a packet. 2 In the Contention-free Period, the AP sends Contention-Free-Poll (CF-Poll) packets to each station, one at a time, to give them the right to send a-packet. The Interframe Space is a key technology to control the packet sending. Please draw the PCF frame transfer according to the following example. (24) There are 5 packets in AP. H1 contains a packet, H2 contains a packet, H3 contains a packet and H3 contains a packet