Honeywell International Inc. 480628-4096 Manuale Utente

Pagina di 214
Advanced WaveLAN Parameters
Medium Reservation
WaveLAN IEEE 802.11 PC Card User’s Guide
4-11
About the Medium Reservation Mechanism
4
When you enable Medium Reservation on a suspect “hidden 
station”, this WaveLAN station and its WavePOINT-II access point 
will use a Request to Send/Clear to Send protocol (RTS/CTS).
The station will send an RTS to the WavePOINT-II device, that 
will include information about the length of the frame that the 
station would like to transmit (see Figure 4-6)
Upon receipt, the WavePOINT-II device will respond with a 
CTS message to all stations within its range to:
— Notify all other stations to defer transmissions for the time-
frame of the requested transmission.
— Confirm the requestor station that the WavePOINT-II has 
checked the medium for availability, and has reserved it for 
the time-frame of the requested transmission. The CTS 
process is Figure 4-7 on page 4-11.
Figure 4-7  Medium Reservation “Clear to Send”