teresa
11-25-2003, 11:48 AM
Hello, I've been reading the 802.11 standard and I have several questions about it:
1) In which situations is there a need (or interest) to implement PCF? When I buy an AP is this already defined and cannot be altered or can I change this in the configuration of the AP? The terminal stations can only work with PCF or DCF, i.e, with only one of these modes? How can I configure this?
2) Which type of frames need an ACK? Is there an ACK for each frame or fragment?
3) What is the directed traffic (or frame)? Is it the same as unicast traffic?
4) The DTIM works the same way as the TIM but only for buffered broadcast or multicast frames?
5) From what I understood the terminal sation doesn't buffer the frames. It only is allowed to have one frame pending. Is this correct? It keeps the frame as long as it waits for an ACK? How long does the station keeps the frame or how many retransmissions it is allowed to do? And when it uses fragmentation, how does it work?
6) On the AP side it only buffers the frames for stations on power save mode? The algorithim to manage this buffer is outside the standard's scope. Where can I find information about this buffer?
Sorry about the long list.
Thank you
1) In which situations is there a need (or interest) to implement PCF? When I buy an AP is this already defined and cannot be altered or can I change this in the configuration of the AP? The terminal stations can only work with PCF or DCF, i.e, with only one of these modes? How can I configure this?
2) Which type of frames need an ACK? Is there an ACK for each frame or fragment?
3) What is the directed traffic (or frame)? Is it the same as unicast traffic?
4) The DTIM works the same way as the TIM but only for buffered broadcast or multicast frames?
5) From what I understood the terminal sation doesn't buffer the frames. It only is allowed to have one frame pending. Is this correct? It keeps the frame as long as it waits for an ACK? How long does the station keeps the frame or how many retransmissions it is allowed to do? And when it uses fragmentation, how does it work?
6) On the AP side it only buffers the frames for stations on power save mode? The algorithim to manage this buffer is outside the standard's scope. Where can I find information about this buffer?
Sorry about the long list.
Thank you