内容r1intelmac标头压缩.pdf

Overview • For MU operation, PHY data rates as low as 900 kbps (MCS0 in 2 MHz) have been proposed, maybe as low as 450 kbps (MCS10 in 2 MHz) • At 900 kbps a 1.5ms PPDU carries 168 octets • QoS Data MAC overhead is 30 octets or 17% • At 450 kbps overhead is twice as high • We propose a simple header compression scheme that minimizes the MAC overhead at low data rates Slide 2 In UL TXOP Sequence TXOP AP Trigger MBA STA1 Data STA2 Data STA3 Data • The AP sends a trigger frame that allocates UL resources • The STAs respond with data • The AP acknowledges received data • S e the resource allocation is controlled by the AP, the AP knows the contents of the following fields in the UL MPDUs: – Duration/ID – Receive address (Address 1) – Transmit address (Address 2) Slide 3 In Header compression proposal Figures from 802.11ac B1 in MPDU Delimiter (let’s call it the Compressed field) indicates presence or absence of Duration/Address 1/Address 2 • Bit B1 in the MPDU delimiter indicates whether or not the Duration/ID, Address 1 and Address 2 fields are present – B1 = 0 ➔ Duration, Address 1 and Address 2 are present – B1 = 1 ➔ Duration, Address 1 and Address 2 are absent • The FCS is calculated as if the fields were present, i.e. the FCS has the same value whether or not the fields are present Slide 4