Hi, Cengiz. This is a highly complex and confusing matter. The answer would depend on dozens of variables: * what APs are used, how are they configured, rates, etc. * client capabilities: the number of antennas, the number of spatial streams, ability to support 40mhz channels. * RF environment: amount of interference, amount of obstacles, client density * Traffic patterns, etc Let's take a typical 2x2:2 802.11n AP and mobile device with 1 antenna. This will give you just one spatial stream and not  MRC at client. Furthermore, because 2.4Ghz could support only ONE 40MHz channel w/o interference, you will most probably use 20Mhz channels. Now, this setup is no different RF-wise for 802.11n and 802.11g, there will be little to none coverage difference. The protocol differences, however might give 802.11n some performance gain, BUT: they will hugely depend on RF environment and patterns of traffic. It requires a clear air and heavy constant traffic streams for all those tweaks to work consistently. Let's looks at two major performance contributors for 802.11n (protocol-wise): * Shortened guard intervals - obviously they reduce wait times, but if you have lots of clients or unstable RF-environment you would want to INCREASE these intervals to reduce the number of retries. * Packet Aggregation - works well for sustained load (streaming video/voice, downloading large files). In a typical MC9090 application (yard/warehouse) the amounts of traffic are minuscule, so is this performance tweak. So, for a single-antenna 2.4 Ghz 20-mhz wide mobile device in a warehousing application the differences between 802.11n and 802.11g are negligible. Now, remember, that the faster the protocol is - the more it is prone to errors because of poor air quality (because most of these speed tweaks are based on removing some protection mechanisms/assuming better air quality). What we normally did for the warehouses was using 802.11b only, fixing the rates at 1-2mbps. Such throughput is more than enough for any warehousing application I've encountered, but using 1-2Mbps rates forces devices and APs into CCK modulation mode which is really tough and can handle lots of RF issues and gives you the most coverage because of lowest SNR requirements. So, the best answer for your customer could be "use 802.11b" as well. Again, this depends on lots of variables. This is what Wi-Fi experts are for :) Unfortunately, I have never seen any official documentation. Our own 802.11n WLAN papers claim AP range increase (because of MIMO, SDM, MRC and other things that are not applicable to this scenario). The links you mentioned cannot be considered definitive sources, since they come from vendors and some anonymous crowd on Wikipedia (which is mostly correct, but NOT the definitive source). I would advice contacting Rajiv Iyer from the WLAN BU - he is the competitive guy and can provide you with some "official" papers. Hope this helps.