Bienvenidos a Soft-Tecni.Net
Sistemas Operativos => Linux => Mensaje iniciado por: hdjpluluazb en Abril 20, 2013, 04:31:45 am
-
Are personal electronics a risk to commercial aviation
generate E-M field), while the other appliances produce only a E-M noise, which is a lot weaker, see
Small Aircraft RF Interference Path Loss:
One particular issue with cell phones is that when they get far from the ground station (or lose connection to the ground station), they transmit a lot stronger signal to maintain the connection or to discover a station (the transmitted signal power varies in range 20 mW - 3 W, see also Mobile phone radiation). While one cell phone doing this would still most likely still be quite weak, having 400 cell phones transmitting at full intensity is something which could create an interference. This also explains why phones are not "confiscated" (like a knife would be) - a few of them left active does not matter, but having many of them could.
Besides of aircraft safety there are other concerns: active cells phones in the plane are bad for the phone operators paul smith 財布 (http://www.asthme.csst.qc.ca/rrap/mauvais.html), as the ground infrastructure is not designed for a situation like this. While the phone is quite far, it has a direct visual connection to many ground stations シャネル バッグ (http://www.elexience.fr/imp/08-tia.htm). See Mobile Phones and Aircraft
As the number of lines available in a particular cell is limited, the cells are sized according to the predicted number of simultaneous users. Inner-city cells are smaller than rural ones エルメス 財布 (http://www.gordonmoody.org.uk/Template.asp), based on the likelihood that there will be a greater demand for lines. Consequently プラダ バッグ (http://www.gamblingtherapy.org/Settings.asp), there are more cells per unit area in cities than elsewhere. It is also worth noting that the line-of-sight link from a mobile phone to a particular base station in a city is likely to be obstructed by buildings.
An aircraft could be carrying 500 cellphones. While passing directly over a city and thus unhindered by buildings, these phones could be in the line-of-sight of hundreds of base stations and could try to register with all of them. This would impose a temporary but extreme load on the network. using a satellite link. One paper attempting to design a scheme like this is ETSI White Paper No. 4, GSM operation onboard aircraft バーバリー 財布 (http://www.intecur.com/japanese/services.html).
Clearly they do not interfere every time, and not every interference would result in a crash, and proof after the fact would be difficult. So the fact that no crashes have been blamed on this is not, by itself, proof that they pose no risk.
As to why all devices might be banned, airlines tend to err on the side of less lawsuits and less violations. The regulatory policy is clear that Airlines (in the US) are responsible for the effects of electronic devices operated on their planes, so they are going to be very hesitant to allow usage -- especially since research by the RTCA shows that some devices do interfere プラダ 新作 (http://www.gamblingtherapy.org/Settings.asp).
another reason for a blanket ban is the impossibility of testing and verifying each and every piece of electronics a potential passenger might have in his posession シャネル ネックレス (http://www.elexience.fr/imp/08-tia.htm), let alone training flight attendants to recognise and differentiate between all of them (often placed in covers, bags, skins) and remember which are or are not allowed. And situations like "yes sir, your eReader has to be turned off because it has a WiFi transmitter バーバリー 時計 (http://www.intecur.com/japanese/services.html), the person next to you has a different model without such a transmitter so it is ok" isn going to go down well with many passengers either. jwenting Oct 4 '11 at 8:48
It appears it is based on reasonable data. I have no knowledge about any FAA research, but (not so recently) the Mythbusters tackled the myth that it is forbidden to use cellphones to force you to use the on-board phones.
They had to build their own mock-up cockpit and throw a whole lot of interference-causing stuff at it, which sort of worked gucci (http://www.seehydropower.eu/inc/menu.php). However it supposedly only worked because the wires in their mock-up weren't properly shielded. This would be supported by their failure to cause any sort of interference in a corporate jet (a Hawker 800XP) ルイビトン (http://www.vroomvroomvroom.com.au/pa-travel.asp).
Related articles:
louis vuitton Is a single big item of luggage ok in long haul flights (http://aisyb.com/forum.php?mod=viewthread&tid=437629)
エルメス How To Make a Canopy Using Canvas Print (http://www.xzxx.cn/uchome/space.php?uid=10686&do=blog&id=189692)
バーバリー 財佈 Diamond Pet Foods expands recall (http://stars.coms.hk/forum.php?mod=viewthread&tid=282082)
hermes Entertaining made easy (http://www.onedayonecard.com/165/sending-thank-you-cards-after-job-interview/)
エルメス バッグ Pro's And Con's Of Cheap Car Insurance (http://bbs.fcbjzs.com/read.php?tid=484942&ds=1)