On Thu, Apr 23, 2009 at 1:34 PM, nir grinberg <n...@grinberg.org> wrote: > The current issue with the > providers are the fact that their data network coverage is not similar > to their GSM coverage. in many locations you will be able to talk via > GSM, but receive a very poor data connection.
That's because there are three different networks involved here. Orange runs 3 networks. a 900mHz GSM (voice and data up to 14.4kbps if they allow it), 1800Mhz (voice, 14.4k data and higher speed data (GPRS?) ) and a 2.1gHz 3G network. The 900 mHz network covers all of the State of Israel and the territories, for legal reasons it does not cover the PA (nudge, nudge, wink wink). The 1800 mHz network has a shorter range for each cell and covers less. With the shorter wavelength there are more "dead spots". The 3g network is similar to the 1.8gHz network in coverage, I have no idea about the number of cells. Cell-Com has an 800mHz D-AMPS network (voice and 9.6k data if they allow it), an 1800mHz GSM network (voice, 14.4k data and higher speed data) and a 2.1gHz 3G network. Coverage is similar to Orange's. As far as signal path, the 1800mHz and G3 networks have the same problems with signals being stopped by things like paper, "sandwich" type wood, trees, etc that wifi has. In fact, it's best to think of them as "wifi on steroids" when it comes to propigation and coverage. They also suffer from the effects of multipath (reflected signals) and the fact that the least power of a signal is at a multiple of half of the wavelength aka "nulls". So you can get a good signal at one location and 6 inches farther away from the cell get nothing useable. It also suffers from the effects of antenna orientation (polarization) so a vertical antenna will get 100 times the signal as a horizontal one. So not only is it possible to be out of coverage of the data network, it's easily possible to be in a "bad location". Geoff. -- Geoffrey S. Mendelson N3OWJ/4X1GM Jerusalem, Israel _______________________________________________ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
