Why 802.11n
Faster Throughput
Megabits per second throughput speeds for WiFi adapters:
- 802.11b max throughput = 5.5Mbps
- 802.11a/g max throughput = 25Mbps
- 802.11g/n max throughput = 75 Mbps
- 802.11a/n max throughput = 150Mbps
Multiple Input and Multiple-Output (MIMO)
802.11n Multiple Input and Multiple-Output (MIMO) radio technology essentially offers three benefits to the client:
Maximal Ratio Combining. The Access Point (AP) combines multiple received signals and increases receive sensitivity.
Transmit Beamforming. Ensures that the signal the AP sends is received in phase by the client, and increases receive sensitivity.
Spatial Multiplexing. Multiple antennas transmit concurrently on the same channel. This increases bandwidth.
Even clients with 802.11a/b/g adapters can take advantage of the Maximal Ratio Combining and Transmit Beamforming benefits. Spatial Multiplexing requires a MIMO capable (802.11n) adapter.
Channel Bonding
In traditional a/b/g networks, each AP uses one 20Mhz wide channel per band (2.4 or 5Ghz). With 802.11n in the 5Ghz band we can bond two 20Mhz channels together into one 40Mhz channel. This increases performance and throughput significantly. (40Mhz channels are only available in the 5Ghz band. Dual band users can be on either 2.4 or 5Ghz.)
- a/b/g devices will have a more consistent and slightly faster connection on the new APs.
- Single band (2.4Ghz) "n" devices will see more consistent connections at faster speeds.
- Dual band "n" devices will see more consistent connections at much faser speeds.
Get the 'n' Benefits
To get both the MIMO benefits and the channel bonding benefits an 802.11n adapter with 5Ghz capability is needed. Typically these are called "dual-band 802.11n" adapters. See our list of recommended adapters for more information.
Cisco works closely with Intel so Intel dual-band 802.11n adapters do great. Dual-Band 802.11n Broadcom, Ralink, and Atheros adapters also seem to work well.
You can look for the wifi certified a/b/g/n logo:
For MOre
For more information, call 801-581-4000 and press option 1 to reach the Campus Help Desk.
