Comparative 11n throughput and range

http://www.networkworld.com/article/2279610/network-security/comparative-11n-throughput-and-range.html

Draft 2.0 802.11n network performance is dependent on so many variables that it can be challenging to get your head around just what to expect with the next-generation Wi-Fi LAN systems. However, Wi-Fi chipmaker Atheros has shared some ballpark throughput numbers based on hypothetical modeling it has conducted in-house.

The table provides estimates of the downlink throughput likely to be realized in Atheros-based networks at various distances and depending on how many antennas and spatial streams are in play. The lion’s share of Wi-Fi systems use Atheros chipsets; many also use the Atheros reference design. Cisco is a notable exception.

802.11n: Approximate Performance and Coverage

Antenna/MIMO Configuration* 2x2 2x3 3x3 No. of Spatial Streams Supported 2 2 2 or 3 Maximum PHY (Connect) Rates 300Mbps 300Mbps 2 Spatial Streams 3 Spatial Streams** 300Mbps 450Mbps Comparative Throughput at Range (in Mbps)*** 50ft 100ft 150ft 50ft 100ft 150ft 50ft 100ft 150ft 50ft 100ft 150ft 185 90 55 250 110 71 266 136 89 Not yet tested * Number of antennas on transmitting device times number of antennas on receiving device **Not yet available in commercial product *** Downlink speeds; environment-dependent; based on hypothetical 802.11n modeling Source: Atheros

In addition to the core chips and system implementation, some other key contributors to actual throughput include the following:

* Architecture of the WLAN system."MIMO, antennas and streams - oh, my!" and"What 802.11n tech specs mean").

* The mix of clients in your environment and their degree of “stickiness.”

* The mix of mandatory and optional 802.11n features supported in the pre-standard 802.11n devices you use.

* How many antennas are used in the system and how many spatial streams are supported (see

* Whether you operate in 40MHz dual-channel mode or in 20MHz single-channel mode.

* Whether 11n APs are serving 802.11a, b or g clients as well as n clients.

And so on. In the coming months, we’ll take a look at each of these items a bit more under the microscope.