On Fri, Sep 28, 2012 at 12:05 PM, Brian Conrad <[email protected]>wrote:
> Walking outdoors in this neighborhood where that tower is over 2 miles > away I don't get any drops while listening. So to the mobile wonks here > why would I get dropouts right at the tower? The phone is an unlocked > Galaxy Nexus and the carrier is 4G or HSPA. Signal was 3 or 4 bars right > there at the tower. This could be useful to know if someone argues back > that the cell tower is right next door and not connecting. > > This is actually pretty easy to explain. Think of it this way, start with a sphere and a single point source of electromagnetic radiation (technically an isotropic radiator<http://en.wikipedia.org/wiki/Isotropic_radiator>of say light or radio waves). This theoretical antenna would take all the radio wave energy from the cell site and distribute it equally across all points on a sphere - much of it down into the ground or up into outer space. This is simply wasted energy (ET never paid for earthbound cell service and warming the dirt even slightly doesn't pay well either thus neither form a viable revenue stream for the carrier). This is why they when you look at most cell sites they use an array of sectoral antennas. They are called *sectoral* because each antenna in the array focuses it's energy in only a specific* section* of that sphere that's useful and brings revenue to the carrier. That said, each section is generally similar in shape to an oval squatted cone projecting outward from the cell site and focused at the horizon or maybe with a few degrees of downtilt but not much more. thus if you are standing right under the tower the radio waves are probably shooting right over your head off to illuminate some guys cell phone blocks to miles away from you while the tower he's standing under may actually be stronger at your location than it is to him standing under it and vice versa. Hopefully this kinda explains the physics involved in the RF side of cellular. It's not a software question which is what most of us here do. Eric -- You received this message because you are subscribed to the Google Groups "Android Discuss" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/android-discuss?hl=en.
