4G Communications and more

I attended another IAAP lecture on 4G Wireless Communications [1]. We hear the term 3G and 4G, etc., but what does characterize 4G technology? Several properties: mobility, which immediately requires it being wireless, broadband (being able to send and receive different types of data), speed, and adhering to requirements of International Telecommunications Union (ITU), a division of United Nation, where telecommunication leaders of all countries meet and set the requirements and standards.

We also learned about how different carriers use different frequencies of the spectrum to avoid interferences. The speaker talked about some companies fighting with agencies such as FAA because their technologies are using frequencies very close to the boundaries of the frequency ranges that are used for GPS technology for aviation for example, among other applications. These concerns have led to deployment of a website for avoiding such problems, called Save Our GPS! [2]

As the time for questions and answers came, and as the topic of interference and FAA came up and there was at least one telecommunication expert in the room, I had to ask about the regulations restricting cell phone use on planes. Even though the speaker was not very happy with all the restrictions FAA puts on telecommunication companies, he immediately answered by saying the minimum effect cell phones on planes have is that they add background noise to the signals. In an ideal case, we expect all devices to use only the frequencies they are designed for. If that happens, there would be no problem. But other times, a technology such as cell phone may try another modulation of the frequency it is designed for, in which case it might be the same frequency that a device on plane is using, and thus cause interference. He suggested you can see the effects of your cell phones interference when you walk in front of your TV using it. I always think about how easily interferences or another problem, not receiving a signal, can occur by thinking about old fashioned radios we had back home. If we moved in front of it or moved the antenna a little here or there, it affected the performance of the radio. So does throwing in more signals, noise, static, or parazit at it.

[1] http://www.iaadc.net/2011/09/lecture-41-4g-wireless-communications/
[2] http://www.saveourgps.org/