Below is a list of tips to understanding your wireless network issues and improving wireless speed.
Have realistic expectations - first, please have realistic expectations for wireless network performance. The theoretical maximum speeds for
802.11 Wi-Fi variants quote ideal conditions, transfers in both directions and shared between all network devices. Real-life actual
downstream speeds considering
protocol overhead are in the 30-40% range of theoretical maximum speeds for wireless devices, you can find more information
-here-. Also, please note that in data transfers, speed is measured in Megabits per second (Mbps), not Megabytes. For reference, see our
bits/bytes conversion calculator.
Use 802.11n clients - note that a newer
802.11n router will not improve your speed if you only use
802.11g/b clients. Also, many
802.11n network adapters are rated at a maximum link rate of 150 Mbits/sec. Don't mix clients - your brand new simultaneous dual-band
802.11n router will slow down by 50% to 80% to accomodate any legacy
802.11b/g clients (while they're activelly transmitting or receiving).
Use WPA2/AES and enable WMM - most
802.11n Wi-Fi certified devices will slow down to 54
Mbps if you use
WEP or
WPA/TKIP security, since the
802.11n specs state that the higher
throughput rates can't be enabled if either of those outdated security methods are being used. Similarly, the
802.11n spec requires devices to support
802.11e (
QoS enhancements for wireless
LAN) in order to use high
throughput link rates, i.e. higher than 54
Mbps.
WMM is a subset of
802.11e that is required for products to be certified for
802.11n.
Only use channel bonding for strong signals - many newer
802.11n routers support channel
bonding, i.e. using 40MHz instead of the default 20MHz channels. This only works for strong signals and small distances. At longer ranges, channel
bonding can actually reduce your performance by 70%+ ! Simple
throughput testing using both channel widths should be performed for your specific location, or simply turn channel
bonding off to accomodate weaker signals.
Keep routers clear of interference - most routers/modems/gateways are not well shielded against electro-magnetic inferference, and they'll work better when away from any possible source of
EMI/RFI. Keep your
router at least one foot away from any other routers, modems, switches, computers,monitors,power supplies, fans, fluorescent lights, cordless phones, etc.
Improve signal strength - it is best if wireless access points are at an elevated point, at least one foot away from any surface that may reflect or attenuate a significant portion of the signal, such as metal/foil insulation, wire-mesh stucco on exterior walls, etc. If installing near the edge of a building, there may be an advantage to using a directional antenna, or building a simple reflector using aluminum foil behind omnidirectional antennas to focus the signal. This is less of an issue with some newer wireless routers capable of
beamforming with built-in phased arrays. If your
router/ap uses removable external antennas, another easy option to improve signal is simply replacing them with longer/stronger omnidirectional antennas.
