Re: Satellite eavesdropping of 802.11b traffic
At 5:41 PM -0700 5/27/04, Bill Stewart wrote: Pringles cans. Okay... I'll bite. What *is* resolution of a Pringle's can at 100-200 miles? 23,000 miles? Cheers, RAH -- - R. A. Hettinga mailto: [EMAIL PROTECTED] The Internet Bearer Underwriting Corporation http://www.ibuc.com/ 44 Farquhar Street, Boston, MA 02131 USA ... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience. -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
RE: Satellite eavesdropping of 802.11b traffic
R. A. Hettinga At 12:35 PM -0400 5/27/04, John Kelsey wrote: Does anyone know whether the low-power nature of wireless LANs protects them from eavesdropping by satellite? It seems to me that you'd need a pretty big dish in orbit to get that kind of resolution. The Keyholes(?) are for microwaves, right? Cheers, RAH I don't claim great expertise, but 802.11b/g operates in the microwave range - My home net falls over every time my kid heats up a burrito (It comes right back, though). GSM phones run at a MAX of 0.25 watts (GSM900) or 0.125 watts (GSM1800), but it is normal for the power used to be one hundredth of this maximum or less. However, the base stations are much more powerful - 50 watts. I suspect the spy-from-orbit stuff looks at this, not the phone transmitter. 802.11b/g typically runs around 0.1 watt, and there is no high-power base station. If this is the case, then the power in an 802.11b/g net is 1/500th of that for GSM phones - which seems to fit in with the difference in range. Phones operate with kilometers to the base station, while 802.11b/g is lucky to cover a whole house. A big antenna would obviously be a lot of help, but a smaller one a lot closer would be better. If you insist on listening from orbit, geosync is probably not the way to go - you'd want something like the Iridium constellation of low-orbit sats (600 miles up). Clarke orbit (geosync) is about 35800 km up. You'd get a 10,000 fold advantage by putting your spysats at only 358km. I suspect that eavesdropping on 802.11b/g from orbit is pretty hard. The power levels are very low, and there may be several nets running on the same channel within a satellites' antenna footprint. My summary: Very tough. Probably not impossible. Peter
Re: Satellite eavesdropping of 802.11b traffic
At 12:35 PM -0400 5/27/04, John Kelsey wrote: Does anyone know whether the low-power nature of wireless LANs protects them from eavesdropping by satellite? It seems to me that you'd need a pretty big dish in orbit to get that kind of resolution. The Keyholes(?) are for microwaves, right? Cheers, RAH -- - R. A. Hettinga mailto: [EMAIL PROTECTED] The Internet Bearer Underwriting Corporation http://www.ibuc.com/ 44 Farquhar Street, Boston, MA 02131 USA ... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience. -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
Re: Satellite eavesdropping of 802.11b traffic
At 04:04 PM 5/27/2004, R. A. Hettinga wrote: At 12:35 PM -0400 5/27/04, John Kelsey wrote: Does anyone know whether the low-power nature of wireless LANs protects them from eavesdropping by satellite? It seems to me that you'd need a pretty big dish in orbit to get that kind of resolution. Pringles cans. You thought the recent restock of the ISS was just for food, and not dual-use?
Re: Satellite eavesdropping of 802.11b traffic
On Thu, 27 May 2004, Roy M. Silvernail wrote: It seems to me that you'd need a pretty big dish in orbit to get that kind of resolution. The Keyholes(?) are for microwaves, right? Where better to put the big dish than in orbit? Clarke-belt birds are separated by what, 10 km? So a 5 km dish would be feasible. No big dish should be needed for resolution. Radio astronomy is done by arrays of smaller antennas. Precise measurement of relative position of the satellites can be done about as well as with the antennas on the ground. Smaller dishes in known distance should work as well. We should also keep in mind that the high-sensitive receivers are cooled so they are rather low-noise.
Re: Satellite eavesdropping of 802.11b traffic
R. A. Hettinga wrote: At 12:35 PM -0400 5/27/04, John Kelsey wrote: Does anyone know whether the low-power nature of wireless LANs protects them from eavesdropping by satellite? It seems to me that you'd need a pretty big dish in orbit to get that kind of resolution. The Keyholes(?) are for microwaves, right? Where better to put the big dish than in orbit? Clarke-belt birds are separated by what, 10 km? So a 5 km dish would be feasible. -- Roy M. Silvernail is [EMAIL PROTECTED], and you're not http://www.rant-central.com is the new scytale Never Forget: It's Only 1's and 0's! SpamAssassin-procmail-/dev/null-bliss
