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AirOS » Historique » Version 58

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Laurent GUERBY, 25/11/2014 14:12


AirOS

http://en.wikipedia.org/wiki/List_of_WLAN_channels
http://wireless.kernel.org/en/developers/Regulatory
http://wireless.kernel.org/en/developers/Regulatory/Database

Band [MHz]    Max BW [MHz]    Flags    Max antenna gain [dBi]    Max EIRP [dBm (mW)]
2402.000 - 2482.000    40.000        N/A    20.00 (100.00) => 80 MHz

5170.000 - 5250.000    40.000        N/A    20.00 (100.00) => 80 MHz
5250.000 - 5330.000    40.000    DFS    N/A    20.00 (100.00) => 80 MHz
5490.000 - 5710.000    40.000    DFS    N/A    27.00 (501.19) => 220 MHz 
(total 5 GHz 380 MHz, 5600-5650 = radar = 50 MHz)

http://www.ubnt.com/wiki/RF_Compliance

For example, if you select 5805 MHz (40 MHz channel) and Below, the radio will use (5775 to 5795 MHz) + (5795 to 5815 MHz),
but if you select 5805 MHz (40 MHz channel) and Above, the radio will use (5795 to 5815 MHz) + (5815 to 5835 MHz).

ath9k http://wenku.baidu.com/view/ac0523f57c1cfad6195fa7f4.html

Ubnt founder: http://www.forbes.com/forbes/2012/0116/entrepreneurs-robert-pera-computer-hardware-apple.html

Commandes utiles

gestion config via ssh: http://gregsowell.com/?p=3457

vi /tmp/system.cfg
Once you have edited your config file, you must save it to flash:

cfgmtd -f /tmp/system.cfg -w
Once you have saved it you can reboot by issuing the “reboot” command or you can do a soft apply:

/usr/etc/rc.d/rc.softrestart save

upgrade firmware via ssh: http://stfunoo.be/?p=1120

v5.3.5

http://wiki.ubnt.com/AirOS_5.3

Channel width 5/10/20/40

TX power min max dBm
Loco 4 23
NS 8 27
NB 4 23
Rocket -4 27

LocoM2 5/10/20/40 dBm 5-23

Comparaison

5.3.5 vs 5.5

Linux version 2.6.15-5.2 (buildd@builder) (gcc version 4.1.2) Mon Dec 19 20:46:46 EET 2011 (janvier 2006)
Linux version 2.6.32.54 (buildd@builder) (gcc version 4.1.2) Fri Apr 6 14:56:27 EEST 2012 (decembre 2009)

6842240 May 19 17:07 XM-v5.3.5.build11245.bin
6472831 May 19 17:07 XM-v5.5.build12536.bin

v5.5

http://www.ubnt.com/download#doc
http://www.ubnt.com/downloads/guides/airOS/airOS_UG_V55_3-20-12.pdf

Country Compliance Mode Frequency 4920 Mhz a 6100 MHz
Channel width 3/5/8/10/20/25/30/40

TX power min max dBm
Loco 4 23
NS -4 27
NB -8 23
Rocket -4 27

LocoM2 3/5/8/10/20/25/30/40 dBm 5-23 Freq 2312 a 2732 MHz (France 5/8/10/20/30/40 et 2412-2472)

IPv6 supported in command line ping6 fe80::xxx%br0 works

Tagger les 2 ports ethernet sur firmware 5.5:

NB:La NS doit déjà fonctionner sans VLAN en mode bridge.

Onglet Network:

  • Configuration Mode: Advanced
Dans "VLAN Network":
  • Ajouter le LAN0 avec VLANID 12
  • Ajouter le LAN1 avec VLANID 12
Dans "Bridge Network" pour le "Bridge0":
  • Supprimer LAN0
  • Supprimer LAN1
  • Ajouter LAN0.12
  • Ajouter LAN1.12

Et appliquer la configuration.

Voila il reste plus qu'à configurer la machine/router pour utiliser ce vlan.

Exemple avec linux:

# ip link add link eth0 name eth0.12 type vlan id 12
# ip link set eth0.12 up
# ping6 -c1 fe80::31%eth0.12
PING fe80::31%eth0.12(fe80::31) 56 data bytes
64 bytes from fe80::31: icmp_seq=1 ttl=64 time=23.5 ms
--- fe80::31%eth0.12 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 23.519/23.519/23.519/0.000 ms

Forums

http://en.wikipedia.org/wiki/Beamforming
Beamforming alters the phase of each element in an antenna array to create spatial beam patterns through constructive and destructive interference.

http://en.wikipedia.org/wiki/Space%E2%80%93time_code
Space-time coding/processing performs antenna diversity with multiple antennas at either transmitter or receiver side or both sides, where every antenna element is separated from its nearest element by around 4 to 10 times the wavelength to keep the signal through each multi-path independent. The distance between two adjacent antenna elements is relying on the angular spread of the beam signal.

http://en.wikipedia.org/wiki/Multi-user_MIMO#Space-division_multiple_access_.28SDMA.29
SDMA is a common and typical multiple input multiple output scheme in cellular wireless systems. SDMA is often referred to as simply a MIMO system since the half port of a SDMA system also consists of multiple users. Although SDMA is indeed a MIMO technique, MIMO is not necessarily SDMA.

http://en.wikipedia.org/wiki/Spatial_multiplexing
Spatial multiplexing is performed by multiple antennas equipped at both a transmitter and a receiver front end.

http://en.wikipedia.org/wiki/Cooperative_wireless_communications
Cooperation are known as network MIMO systems, distributed MIMO systems or virtual antenna array systems. Mobile devices use the partnered mobile devices' antennas, antenna arrays, or antenna elements as virtual antennas."

proposed things despite "generalised" description in original company press-release: "MU-MIMO works by enabling simultaneous transmission to groups of clients, making better use of available WiFi network capacity and speeding up transmissions.

also wiki-suggested articles in reference - not bad(IMO):

http://dx.doi.org/10.1109/MSP.2007.904815

http://dx.doi.org/10.1109/JSAC.2013.130205

http://kth.diva-portal.org/smash/get/diva2:608533/FULLTEXT01

http://dx.doi.org/10.1109/TWC.2010.092810.091092

covering different aspects, but i found especially inreresting last two.

ACK Hardware limits are:

40MHz - 15.2 miles (24.5 km)
30MHz - 32.5 miles (52.3km)
20MHz - 32.5 miles (52.3km)
10MHz - 65.2 miles (104.9 km)
8MHz - 65.2 miles (104.9 km)
5MHz - 130.9 miles (210.7 km)

AirView test

References:

Lab on table same room compliance mode 5.5
- one NSM5 AP WDS
- one LocoM5 STA WDS 1 meter from the NSM5
- one NBM5 head (without dish) right in between Loco and NS running AirView

Steps for each graph
  1. associate NS and Loco with new frequency and width
  2. clear airview
  3. launch 300 second iperf client between netbook behind NSM5 to iperf server on locoM5
  4. after iperf is done save airview screenshot
  5. go back to step 1

First batch testing narrow channels 5240 with 5200-5300 airview:

  • 3 MHz
  • 5 MHz
  • 8 MHz
  • 10 MHz
  • 20 MHz

Second batch testing large channels 5300 with 5200-5400 airview:

  • no emission to verify noise
  • 10 MHz
  • 20 MHz
  • 30 MHz
  • 40 MHz