Wireless Standards

This article lists common standards and basic features that are relevant to OpenWrt.

Old standard that operates in 5GHz frequency band

IEEE_802.11a-1999

IEEE_802.11b-1999 Operates in 2.4GHz Band Old standard.

IEEE_802.11g-2003 Operates in 2.4GHz Band Old standard.

IEEE_802.11n-2009

IEEE_802.11ac Also called “Wifi 5”

IEEE_802.11ad Not very common in OpenWrt.

IEEE_802.11ax

Also called “Wifi 6”

Each hardware has certain features that can be queried in OpenWrt by using

iw phy <phy interface> info 

Mismatching features result in compatibility problems and possibly reduced data transfer rates.

example:

RX LDPC
HT20/HT40
SM Power Save disabled
RX HT20 SGI
RX HT40 SGI
TX STBC
RX STBC 1-stream
Max AMSDU length: 3839 bytes
DSSS/CCK HT40

Technology that uses multiple antennas to increase data transfer rates. see also MCS tables

STBC is part of MIMO.

MU-MIMO

Required for higher throughput - 802.11n, 802.11ac, 802.11ax standards. HT … 802.11n , VHT … 802.11ac, HE … 802.11ax

HT20 : 20 MHz wide channels HT40: 40 MHz VHT80 : 80 MHz VHT160: 160MHz

see also MCS table

often visualized as a table. The MCS Index is a value that the hardware supports and uses when communicating.

Low data rates mean the higher indexes are not used. Reasons might be configuration or interference.

Acronym for Radio Simultan Dual Band, Dual Band Dual Concurrent

Use two frequency bands at the same time by one endpoint.

Supported by: mt76 and potentially brcmfmac ( BCM4359 )

Normally radios operate in Single Band Single Concurrent (SBSC) (OpenWrt: 802.11an, 802.11bgn) or are capable of Dual Band Single Concurrent (DBSC): having 2 frequency bands selectable (OpenWrt: 802.11abgn capable).

Wake-on-LAN

some MCS Tables