Controller Based WLANs

What is the difference between 36+ and 40- notation in the controller?

Product and Software:This article applies to all Aruba controllers and ArubaOS 3.3.x and later.

 

For 36+, Channel 36 is the primary or control channel and Channel 40- is the secondary or extension channel. For 40-, Channel 40 is the primary or control channel and 36 is the secondary or extension channel. For 11n clients, it does not make much difference. However, legacy clients (11a) connect only to the primary channel. This fact can be used to balance 11a clients across 36 and 40.

 

Channel Bonding

 

Channel bonding is used primarily with 5 GHz (IEEE* 802.11a) systems as it is the best solution for increased bandwidth with reduced possibility of interference.

 

The possible channels for 5 GHz systems are: 36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 149, 153, 157, and 161.

 

Note: Channels may be slightly different depending on the regulatory requirements of the country.

When selecting the two channels, the primary or control channel is selected first. The secondary or extension channel is selected in relation to the primary channel.

 

For example, if the primary channel is 36 and the secondary channel is 40, the notation would be (36,1). If the primary channel is 44 and the secondary channel is 40, the notation would be (44,-1). The primary and secondary channels are always next to one another. It is impossible to have a primary channel of 36 and a secondary channel of 56.

 

Supported combinations of 802.11n channels at 5 GHz with 40 MHz bandwidth are:

 

(36,1) (40,-1); (44,1) (48,-1); (52,1) (56,-1); (60,1) (64,-1); (100,1) (104,-1); (108,1) (112,-1); (116,1) (120,-1); (124,1) (128,-1); (132,1) (136,-1); (149,1) (153,-1); (157,1) (161,-1)

 

Note: It is recommended that channel bonding be used in the 5 GHz band due to the limited number of nonoverlapping channels available in the 2.4 GHz band.

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Last update:
‎07-02-2014 06:08 PM
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