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The Mobile Internet You'll Be Using In 10 Years
mr sanjeev writes "After being plagued with project overruns and a scaling back of the final system, the US military's next-generation satellite communications network is another step closer to reality, with completion of the payload module for the third and final Advanced Extremely High Frequency (EHF) satellite ... If GPS and remote imaging (think Google Earth) have proven anything, it is that technology initially developed for military purposes, and extremely expensive for initial civil use, will eventually reach the point where it forms part of our daily lives without us ever being conscious of the massive investment to get to that point."
More important, how's the latency? The RTT to a satellite in geosynchronous orbit is pretty high (especially considering that when requesting data, you have to double the RTT vs. streaming). The article doesn't seem to say if this is high-, low-, or medium-earth orbit.
Low earth orbit can get you RTT to the satellite of ~13 milliseconds at 2000 km, adding ~26 ms to the average page load, whereas a geosynchronous orbit could take ~240 milliseconds, adding ~480ms to a page load - quite a difference. Of course, these are optimal times, assuming the satellite is directly overhead.
That said, it does mention a constellation of three satellites, and there's no way that this could be practical with three satellites in a low- or even medium-earth orbit that I can see. Bandwidth is great, but latency is killer.
Move to Europe - we have a choice of carriers all across europe who can offer this :)
8.2 Mbps to 4k terminals.
Advanced EHF is designed to provide 24 hour coverage from 65 North, to 65 South across the K and Ka sub bands, and when combined with the prototyped Extended Data Rate (XDR) terminals and systems, will offer up to 8.2 Mbps data rates for around 4,000 terminals in concurrent use per satellite footprint (whether that scales to 12,000 systems in concurrent use globally isn't clear from source material).
Compared to current satellite rates, this is pretty good. Additionally, this allows them to bounce satellite signals quickly and reliably around the globe before having to incurr the atmosphere penalty.
However, if you're looking for replacement for WiFi, a final 802.11N spec is only about 10 years off.
The ______ Agenda
It doesn't cost the military anything to have millions of GPS users using their GPS system because the satellites take a passive role. It is the device in your hand doing the calculations based on signals and timing from a few satellites. On the other hand, a communications network actually has a limited resource in the form of bandwidth to be consumed by the millions of potential users.
its been a while since I've seen american citizens being put in jail for loitering....
Then you're not looking very hard. More and more cities are passing increasingly punitive "anti-loitering" laws all the time. Mostly under the logic that they "clean up" downtowns and prevent panhandling.
As for people getting punished for public assembly, just go to Flickr and type in "RNC" and you'll find plenty of people, almost all non-violent and cooperative, fwiw, being stopped from public assembly.
As soon as the feds started this concept of "free speech zones" they had publicly admitted that free speech wasn't predictably allowed anywhere else.
Satellite > Base Station > Your Mobile Device
That's how I imagine it would work. Honestly, do you really think that there are going to be thousands upon thousands of direct connections to the satellites? They would probably have to be sent through switches anyway, so so long as the base station's dish doesn't get tampered with it would work just fine.
10Ghz Space to Base Station, and a more stable protocol (Wireless N, 3G, etc.) to your mobile device.
Random Thoughts From A Diseased Mind (Not For Dummies)
GlobalSecurity has a list of communications systems that the Arleigh Burke class of destroyers have.
# LF through HF Receive,10 kHz - 30 MHz
R-1051 H/URR; twelve receivers
R-2368 H/URR; three receivers
# HF Transmit; 2-30 MHz
AN/URT-23D; nine transmitters
# VHF Transmit and Receive, 30-162 MHz
AN/GRR-211; two transceivers for non-secure voice
ANNRC-46A; two FM transceivers for secure voice
AN/URC-80 (V)6; one transceiver for bridge-to-bridge communications
# UHF Transmit and Receive, 220-400 MHz
AN/URC-93 (V)1; two transceiver for Link 4A
AN/WSC-3 (V)7,11; fourteen transceivers
AN/WSC-3 (V)11, have-quick transceiver
# SATCOM Transmit and/or Receive
AN/SSR-1A; one receiver for fleet broadcast
ANNWSC-3A (V)3; five transceivers for digital voice
# Infra-Red, Transmit and Receive
AN/SAR-7A; two IR Viewers
# Land Line Terminations, Transmit and/or Receive
AN/SAT-2B, one IR Transmitter
Single Channel DC Secure TTY
# Telephone Special Communications Channel
AN/USQ-69 (V)7; OTCIXS
AN/USQ-69 (V)8; TADIXS
AN/SYQ-7 (V)5 and AN/USQ-69 (V)6; NAVMACS/CUDIX
AN/USQ-83 (V) and AN/USQ-125 (V); Link 11
AN/SSW-1 D; Link 4A
AN/SRQ-4; HawkLink (LAMPS MK III)
AN/ARR-75 Sonobouy antenna
A Blackberry operates on the 850/900/1800/1900 MHz GSM network.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
EHF communications is NOT the mobile internet of tomorrow. In fact AEHF won't even be the military's SATCOM system of choice when bandwidth is the primary requirement. They're generally going to turn to WGS (http://www.afspc.af.mil/library/factsheets/factsheet.asp?id=5582) or even more likely, commercial SATCOM because that's where the REAL bandwidth is.
Don't get me wrong EHF SATCOM does what's it designed to do very well. It's protected. The narrow beam widths on uplink and downlink provide low probability of detection & intercept (LPI/LPD). Being that it's a high-gain system (narrow beams, high power) coupled with frequency jumping across an enormous spectrum it makes it very hard to jam. Lastly, and least practical to a civilian user, EHF communications are more resistant to the effects of atmospheric scintillation in a post-nuclear environment.
So, if in 10 years, you find yourself in need of anti-jam, LPI/LPD communications following a major nuclear attack, then YES! EHF SATCOM will be there for you! :)
PS EHF may survive a nuke attack, but heavy rain does knock you off the air! Gotta take the good with the bad. :)