AirDefense Walks the WLAN Wire - Page 5
If you look at 802.11n's MAC [media access control] today, it is definitely a lot more complicated than 802.11a/b/g's MAC. You will see new attacks, new tools, new types of denial of service attacks, new types of spoofing attacks that will emerge. We have to stay ahead of the threat, as that is where a company that has dedicated its life to wireless security research will shine. Have you seen any differences over the last couple years in the levels of interference in the 2.4GHz band? Is it any worse than it was a couple years ago?In our customer base, there is a lot of concern over municipal Wi-Fi deployments. If you have an office in a busy park and there is municipal Wi-Fi all around you, how does that affect your cell plan, particularly given the fact that the 2.4GHz band only has three nonoverlapping channels? How do you go ahead and plan your APs so they don't interfere with the pervasive deployment that is all around you? Among your customers, is adoption of the 5GHz band fairly universal at this point, or is it still underutilized? Overall, I have always been surprised by the slow adoption of 5GHz within the enterprise, but that might change with 802.11n. A lot of the legacy baggage that 802.11n would have to carry in the 2.4GHz band for mixed-mode traffic is not necessarily true in the 5GHz band. 802.11n uses MIMO with OFDM [Orthogonal Frequency Division Multiplexing], and in the 2.4GHz band it would have to do that with legacy DSSS [direct sequence spread spectrum]- or CCK [Complementary Code Keying]-type transmissions. At a high level, mixed-mode traffic-which means high-throughput traffic with legacy traffic-will really kill the throughput benefits that 802.11n promises.
Interference problems have only gotten worse-especially in the 2.4GHz band, which is very crowded. There are a lot of new devices, such as gaming consoles or other media-sharing devices in the home that are leveraging Wi-Fi. While the protocol itself has been designed to avoid collisions, there is only so much it can do.