Comments on: 4G spectrum agreed at ITU-R http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/ Your window into the Wireless Systems Innovation Laboratory Sun, 27 May 2012 13:11:00 +0000 http://wordpress.org/?v=2.0.3 by: Bob Daniels http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-23391 Wed, 21 Nov 2007 16:36:09 +0000 http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-23391 Can someone explain to me what exactly the IMT-Advanced standard's (or should I say requirement's) purpose is? For example, IMT-2000 led to the CDMA2000, EDGE, and DECT standards and I also know that IEEE standard working group members also want to make sure they are following IMT-Advanced's requirements for next generation wireless LAN. I guess my real question is, what is the political process? What is the real function of ITU and how does it contribute to the political process? Obviously we see here that international spectrum regulation is part of its function, but I've noticed that there is much ambiguity in these political processes...especially spectrum regulation. Sorry I seem clueless, but I've read many reports from these organizations, and it's not clear to me where the functional boundaries are drawn. Can someone explain to me what exactly the IMT-Advanced standard’s (or should I say requirement’s) purpose is? For example, IMT-2000 led to the CDMA2000, EDGE, and DECT standards and I also know that IEEE standard working group members also want to make sure they are following IMT-Advanced’s requirements for next generation wireless LAN. I guess my real question is, what is the political process? What is the real function of ITU and how does it contribute to the political process? Obviously we see here that international spectrum regulation is part of its function, but I’ve noticed that there is much ambiguity in these political processes…especially spectrum regulation. Sorry I seem clueless, but I’ve read many reports from these organizations, and it’s not clear to me where the functional boundaries are drawn.

]]> by: Takao Inoue http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-23172 Mon, 19 Nov 2007 19:07:15 +0000 http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-23172 I read somewhere that over 100 countries has agreed on 3.4-3.6GHz for this, so I would speculate 3.4-3.6 is probably the strongest candidate. But since 2.3 was included to pickup WiBro spectrum, it's still unclear to me which direction this might fall. I agree it doesn't look like 100MHz channels are happening here. I'm guessing these spectrum will most likely use 10-20MHz OFDM channels? I read somewhere that over 100 countries has agreed on 3.4-3.6GHz for this, so I would speculate 3.4-3.6 is probably the strongest candidate. But since 2.3 was included to pickup WiBro spectrum, it’s still unclear to me which direction this might fall.

I agree it doesn’t look like 100MHz channels are happening here. I’m guessing these spectrum will most likely use 10-20MHz OFDM channels?

]]> by: Ramya Bhagavatula http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-23162 Mon, 19 Nov 2007 18:24:34 +0000 http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-23162 Not really. the antennas do not have to be a foot long. The ones used in cell phones and other mobile devices are usually PIFAs (planar inverted-F antennas) or microstrip (patch) antennas. There are a number of ways that you can reduce the size of these antennas. For example, for patch antennas, you can simply change the dielectric substrate - lower frequencies can use substrates with higher dielectric constants. So, in short, we do not necessarily have to use a bigger patch. Another interesting point to note here is that patch antennas can be made to resonate at different frequencies by cutting slots in them, making wedges etc. So, we can effectively reduce the resonant frequency without having to increase the antenna size. Not really. the antennas do not have to be a foot long. The ones used in cell phones and other mobile devices are usually PIFAs (planar inverted-F antennas) or microstrip (patch) antennas. There are a number of ways that you can reduce the size of these antennas. For example, for patch antennas, you can simply change the dielectric substrate - lower frequencies can use substrates with higher dielectric constants. So, in short, we do not necessarily have to use a bigger patch.
Another interesting point to note here is that patch antennas can be made to resonate at different frequencies by cutting slots in them, making wedges etc. So, we can effectively reduce the resonant frequency without having to increase the antenna size.

]]> by: Steven Peters http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-22859 Sat, 17 Nov 2007 11:29:05 +0000 http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-22859 How will 400 MHz work in mobile devices? The antenna will need to be, what, a foot? How will 400 MHz work in mobile devices? The antenna will need to be, what, a foot?

]]> by: Robert Heath http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-22837 Sat, 17 Nov 2007 05:56:09 +0000 http://windowsil.org/2007/11/16/4g-spectrum-agreed-at-itu-r/#comment-22837 Very nice! Which of these are global worldwide? It doesn't look like that much spectrum to me. There is all this talk of 100MHz channels but I don't see that many 100MHz channels here ?? Very nice! Which of these are global worldwide? It doesn’t look like that much spectrum to me. There is all this talk of 100MHz channels but I don’t see that many 100MHz channels here ??

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