swissinfo.org— "Not only would the technology, called High Altitude Platform Systems (Haps), make the current 1,000 earth-bound antennas redundant, it would drastically reduce radiation."
Jul 11, 2006View in Crawl 4
This will not happen. I work for a national wireless carrier as a RF Engineer. The power output needed by a cell phone to transmit that far to a tower would be enormous. Ever see the size of a "sat phone?" They're huge due to battery size and the antenna to transmit. On top of the size, sat phones don't work very well and the battery life is s**t. Your current phone uses smart software to determine its distance from the closest tower and adjusts its transmit power accordingly. With today's battery power and cell phones, the signal would never make it up to the blimps at that distance. This happens now when you get too far from a cell tower for your phone to transmit back to it - what you hear is your party on the other end talking just fine (because the cell tower transmits at a much higher power) but the person you're talking to on the other end stops hearing your first in this scenario; usually winds up in them saying something to you like, "Hello? are you there? Hello?" and you on your end saying, "Yes I can hear you, can't you hear me? Hey! I can hear you... I'm here - don't hang up..." This is of course as long as only one of you are experiencing the distance from tower problem... otherwise if it were both of you on cell phones with the same issue, well you know what happens; just duplicate it on the other end.
Let me start by saying, i will take into consideration you definately might be an RF engineer, but you are not good at it. My cell phone operates at the 800MHz band (somewhere between 820 and 845) (thats the lower frequencies, and there is the 1.6GHz frequencies.. anyways.. I have a radio that transmits at 1 Watts and I can easily reach a repeater tower thats 10 miles away using the 144MHz band (with no line of sight). Now its true that the higher the frequency the more the deterioration there will be with distance, but at line of sight and only about 13 miles (thats 3 miles difference) I'm pretty sure the cell phones can easily reach the blimp without any problem at all. The reason that SAT phones require a lot of power because #1- the distance is much bigger than just 13 miles. #2- The ionosphere, magnetoshpere and much other atmospheric layers needs to be penetrated. #3- The RF (also known as PHOTONS) needs to penetrate the atmosphere into space to reach the SAT needs to be powerful enough to be not reflected since it passing from one medium to another. Also comm. sats. uses 4-6 GHz C-Band, 11/12-14 GHz.. to give you a better visualization, WIFI uses 2.4GHz/5 cordless phones use 5.8GHz.. and they operate within Part-15 of FCC regulation, see how much distance you can get out of them, pretty much if its not in your house you'll have terrible SNR (signal to noise ratio).. so in order for SAT phones to reach the sattelites at those frequencies (an example taken from one company..) 400mW +26dbm ~ 10.4W ERP now compare that to a cell phone that does not exceed 5 watts ERP (equivalent radiated power) (some are even less than 1W) go to FCC and check the results from your cell phone's FCC id... this person is not talking about sat phones.. cellular phones with the cells being positioned differently... i see no problem reaching a blimp 13miles above the ground, with physically no obstructions and direct line of sight at the current frequencies... The only problem, is that if you are in the basement of a high rise and the blimp is directly above you, then you have to cut through the height of building, which is definately a problem, but there are such things as IBR (In-Building Repeaters)...my sources: www.wikipedia.com and www.google.com and ofcourse my cell phone and FCC.
A couple of things:- 20 - 100 km is 'near space' (though there is no legal definition)- while Iridium was a failure for Motorola, the constellation is alive and well (after some initial failures). Hand-sets are a bit big, but it's still useful for a lot of people who aren't near a cellphone antenna (or high-altitude airship).- I've spoke to one of the Sanwire reps at a recent conference. This stuff IS going to happen, it will not totally replace cell phone technology though. Also check out jpaerospace.com- someone mentioned using LESS power to reach blimps. This would be correct only if you used a directional antenna. Given that the mobile phone will not always know which direction the "cell" is, omni-directional antennas are needed. Thus MORE power will be needed (nullifying the whole "less radiation" claim for those using the phone next to their heads). On the other hand, some sort of phased array set-up could reduce power requirements. This would be technically difficult though, and also increase antenna size.- UV is an issue at 70k+ feet. Materials issues need to be worked out. Electronics can be shielded, although this adds some weight- The airships are not as vulnerably as you would think. Yes, an air-to-air missile would take it out quite easily, but if we had enemy fighters close enough to do such, we'd have other issues besides mobile coverage. Manpads don't have the range. SAMs can hit it, but we'd have even more of a problem than enemy fighters if they were within range. Military airships (e.g., Combat SkySat) operate in an environment with air-superiority taken care of.- wind at high altitudes is more predictable than lower altitudes, though not a negligible issue.- the government is very interested in doing this. It is MUCH cheaper to design, build, launch and operate a fleet of balloons than it is to launch a signal satellite.- the cell phones would not necessarily be bigger, though I wouldn't expect there to be any RAZR sized phones when they first come out. Given the increased power requirements I'd expect the batteries to be a little bigger (save for a battery break through).Globalstar satellite phones are 12 ounces. - antenna size is a function of frequency, so the antenna will not necessarily be bigger. The atmosphere refracts/bends/scintillates some frequencies whereas blimps will not have to deal with this nearly as much.
lizardslayerJul 11, 2006
There are many things to be worked out, but hurricanes in the stratosphere aren’t one of them. (Even in places like Florida)This is not a new idea – see : <a class="user" href="http://www.sanswire.com/stratellites.htm">http://www.sanswire.com/stratellites.htm</a>
armyturtleJul 11, 2006
This will not happen. I work for a national wireless carrier as a RF Engineer. The power output needed by a cell phone to transmit that far to a tower would be enormous. Ever see the size of a "sat phone?" They're huge due to battery size and the antenna to transmit. On top of the size, sat phones don't work very well and the battery life is s**t. Your current phone uses smart software to determine its distance from the closest tower and adjusts its transmit power accordingly. With today's battery power and cell phones, the signal would never make it up to the blimps at that distance. This happens now when you get too far from a cell tower for your phone to transmit back to it - what you hear is your party on the other end talking just fine (because the cell tower transmits at a much higher power) but the person you're talking to on the other end stops hearing your first in this scenario; usually winds up in them saying something to you like, "Hello? are you there? Hello?" and you on your end saying, "Yes I can hear you, can't you hear me? Hey! I can hear you... I'm here - don't hang up..." This is of course as long as only one of you are experiencing the distance from tower problem... otherwise if it were both of you on cell phones with the same issue, well you know what happens; just duplicate it on the other end.
citizenmattJul 11, 2006
I dugg this because someday I want to hear the message "your call cannot be completed due to blimp failure. Please try again later."
djhashJul 11, 2006
Let me start by saying, i will take into consideration you definately might be an RF engineer, but you are not good at it. My cell phone operates at the 800MHz band (somewhere between 820 and 845) (thats the lower frequencies, and there is the 1.6GHz frequencies.. anyways.. I have a radio that transmits at 1 Watts and I can easily reach a repeater tower thats 10 miles away using the 144MHz band (with no line of sight). Now its true that the higher the frequency the more the deterioration there will be with distance, but at line of sight and only about 13 miles (thats 3 miles difference) I'm pretty sure the cell phones can easily reach the blimp without any problem at all. The reason that SAT phones require a lot of power because #1- the distance is much bigger than just 13 miles. #2- The ionosphere, magnetoshpere and much other atmospheric layers needs to be penetrated. #3- The RF (also known as PHOTONS) needs to penetrate the atmosphere into space to reach the SAT needs to be powerful enough to be not reflected since it passing from one medium to another. Also comm. sats. uses 4-6 GHz C-Band, 11/12-14 GHz.. to give you a better visualization, WIFI uses 2.4GHz/5 cordless phones use 5.8GHz.. and they operate within Part-15 of FCC regulation, see how much distance you can get out of them, pretty much if its not in your house you'll have terrible SNR (signal to noise ratio).. so in order for SAT phones to reach the sattelites at those frequencies (an example taken from one company..) 400mW +26dbm ~ 10.4W ERP now compare that to a cell phone that does not exceed 5 watts ERP (equivalent radiated power) (some are even less than 1W) go to FCC and check the results from your cell phone's FCC id... this person is not talking about sat phones.. cellular phones with the cells being positioned differently... i see no problem reaching a blimp 13miles above the ground, with physically no obstructions and direct line of sight at the current frequencies... The only problem, is that if you are in the basement of a high rise and the blimp is directly above you, then you have to cut through the height of building, which is definately a problem, but there are such things as IBR (In-Building Repeaters)...my sources: www.wikipedia.com and www.google.com and ofcourse my cell phone and FCC.
alistairfJul 12, 2006
A couple of things:- 20 - 100 km is 'near space' (though there is no legal definition)- while Iridium was a failure for Motorola, the constellation is alive and well (after some initial failures). Hand-sets are a bit big, but it's still useful for a lot of people who aren't near a cellphone antenna (or high-altitude airship).- I've spoke to one of the Sanwire reps at a recent conference. This stuff IS going to happen, it will not totally replace cell phone technology though. Also check out jpaerospace.com- someone mentioned using LESS power to reach blimps. This would be correct only if you used a directional antenna. Given that the mobile phone will not always know which direction the "cell" is, omni-directional antennas are needed. Thus MORE power will be needed (nullifying the whole "less radiation" claim for those using the phone next to their heads). On the other hand, some sort of phased array set-up could reduce power requirements. This would be technically difficult though, and also increase antenna size.- UV is an issue at 70k+ feet. Materials issues need to be worked out. Electronics can be shielded, although this adds some weight- The airships are not as vulnerably as you would think. Yes, an air-to-air missile would take it out quite easily, but if we had enemy fighters close enough to do such, we'd have other issues besides mobile coverage. Manpads don't have the range. SAMs can hit it, but we'd have even more of a problem than enemy fighters if they were within range. Military airships (e.g., Combat SkySat) operate in an environment with air-superiority taken care of.- wind at high altitudes is more predictable than lower altitudes, though not a negligible issue.- the government is very interested in doing this. It is MUCH cheaper to design, build, launch and operate a fleet of balloons than it is to launch a signal satellite.- the cell phones would not necessarily be bigger, though I wouldn't expect there to be any RAZR sized phones when they first come out. Given the increased power requirements I'd expect the batteries to be a little bigger (save for a battery break through).Globalstar satellite phones are 12 ounces. - antenna size is a function of frequency, so the antenna will not necessarily be bigger. The atmosphere refracts/bends/scintillates some frequencies whereas blimps will not have to deal with this nearly as much.
cantscanmoneyJul 15, 2006
.Imagine if you could double the size and power of that blimp and brodast WiFi...AWSOME!