What is 802.11n Greenfield mode used for?
A device that uses 802.11n high throughput (HT) mode — also known as Greenfield mode — assumes that there are no 802.11a/b/g stations using the same channel. 802.11a/b/g devices cannot communicate with a Greenfield AP. Instead, their transmissions are likely to collide, causing errors and retransmissions for both parties. Normally, 802.11 devices share channels by sensing when another device is transmitting, using a back-off timer to wait until the …
