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h1. 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

<pre>

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)

</pre>

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

h2. Commandes utiles

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

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

h2. 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

h2. 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

h2. 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

h2. 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:

<pre>

# 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

</pre>

h2. Forums

* http://community.ubnt.com/t5/airMAX-General-Discussion/Ubiquiti-products-700MHz-RF-leakage/m-p/797462#M40669

** Re: Ubiquiti products 700MHz RF leakage Ubiquiti devices operate within FCC limits. It's just the second harmonic from the CPU that could cause interference for Verzion equipment. Either firmware is FCC approved

* http://community.ubnt.com/t5/airMAX-General-Discussion/MU-MIMO/m-p/784294#M40495

To achieve MIMO from a conventional SISO system, several technologies have been proposed.

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.

h2. AirView test

References:

* http://forum.ubnt.com/showthread.php?t=52560

* ETSI EN 301 893 v1.7.0 (2012-01)

* http://www.etsi.org/deliver/etsi_en/301800_301899/301893/01.07.00_40/en_301893v010700o.pdf

** See diagram page 17 of the ETSI PDF

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

# associate NS and Loco with new frequency and width

# clear airview

# launch 300 second iperf client between netbook behind NSM5 to iperf server on locoM5

# after iperf is done save airview screenshot

# go back to step 1

h3. First batch testing narrow channels 5240 with 5200-5300 airview:

* 3 MHz

 !5240-3.png!

* 5 MHz

 !5240-5.png!

* 8 MHz

 !5240-8.png!

* 10 MHz

 !5240-10.png!

* 20 MHz

 !5240-20.png!

h3. Second batch testing large channels 5300 with 5200-5400 airview:

* no emission to verify noise

 !5300-0b.png!

* 10 MHz

 !5300-10b.png!

* 20 MHz

 !5300-20b.png!

* 30 MHz

 !5300-30b.png!

* 40 MHz

 !5300-40b.png!