User`s guide

ARRIS Router Setup – Web GUI User’s Guide
Page 68 of 95 May 2012
Channel Bandwidth – Sets the 802.11n Channel Bandwidth. Options are 20 MHz or 20/40 MHz.
The default setting is 20 MHz. If your wireless network is in a very clean RF environment setting
the Channel Bandwidth to 20/40 will increase your throughput by “bonding” two channels.
However, if there are any other wireless routers or access points within range of the device it
will stay in 20 MHz bandwidth regardless of this setting. This is a WiFi Alliance requirement.
(You can verify the channel bandwidth by using the previously mentioned wireless network
scanning software, MetaGeek’s inSSIDer.)
Guard Interval – The spacing between transmission of symbols in nanoseconds. Can be set to
400ns or 800ns. Selecting 400ns provides higher throughput in networks where the coverage
distance is small (indoors). Selecting 800ns provides higher throughput in networks where the
coverage distance is large (outdoors).
MCS – Sets the 802.11n Modulation and Coding Scheme to be used. Options are 1 through 15
and AUTO. The default is AUTO. The 802.11n standard defines a total of 77 MCS. Each MCS
specifies a certain modulation type (BPSK, QPSK, 64-QAM), coding rate (1/2, 3/4), guard interval
(800 or 400ns), and number of spatial streams. Support for MCS 0 - 15 is mandatory for 802.11n
access points while support for MCS 0 - 7 is mandatory for 802.11n clients.