Recognize, the European Union has defined something different, and Japan So while the US has specified a specific set of patterns that a device must News is that these parameters vary from one regulatory domain to the next. The radar's pulse width, pulse repetition interval, and frequency. The good news is that these patterns are fairly well defined in terms of Of RF radiation, followed by longer periods of listening for the returns. Interference that will be generated by a radar. That something, of course, is to look for the specific patterns of Interference, communication would be painful at best. Simple, though: random interference is far from unknown in the wirelessĭevice bailed out of a channel every time it received some unexpected Should a blast of RF energy hit theĪntenna, the adapter can return an error to the host system indicating thatĪ radar-like patch of interference was encountered. Wireless adapters, having radio receivers tuned to the frequency range of But any device which wants to function as a master - includingĪccess points and anything running in ad hoc mode - must notice radars and Only follow the master device's instructions with regard to where it can A "slave" device, as might be found in a typical laptop, need Most Linux systems will not have to concern themselves directly with radarĭetection. Transmitting on channels where radars are operating. Wireless devices operating in the 5GHz band must actively avoid Shut down all communications and move to a different channel. Radars should one happen to move into the neighborhood, the station must Thereafter, the station must continue to listen for Selection" (DFS), requires that a "master" station listen to a channel forĪ minimum period of time to ensure that no radars are operating thereīefore transmitting. Various agencies have laid out specifications for how a wireless device To make the 5GHz band available for wireless networking in a safe manner, Leading edge of encounters between Linux and the regulatory environment. Rules once again we see how wireless networking often tends to be the These regulators typically show aĭistinct lack of humor toward anybody who doesn't pay attention to their Have strange notions about how aviation safety should take priority Interfering with these radars will be frowned upon by regulators who While other uses of that frequency range areįew, among them are counted air traffic control and weather radars. Will greatly increase the total bandwidth available. Makes it attractive for this use, even though the effective range of anĪccess point is reduced somewhat. For this reason, both 802.11a and 802.11n specify a number ofĬhannels in the 5GHz band as well. Users will have noticed, that band tends to get crowded and noisy in Most wireless networking happens in the 2.4 GHz frequency band as many Some early work is now afoot to give that capability to the Though: wireless networking - especially in a base station mode - will Radar detection may become important for Linux in another context, As far as your editor knows, none of those devices run ![]() ![]() In the US, at least, the term "radar detection" is usually associated withĭevices designed to warn heavy-footed drivers about police officers lurking
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