You don't buy a weeks groceries at a time. You buy what you need for today and tomorrow. Then go shopping again in two or three days. If you need to get alot of groceries you call a cab(I don't know about in the big US cities but around here they even help you load and unload the cars).
The idea is to shoot off a rocket and intercept another rocket or aircraft.
1.) Its like hitting a baseball with a needle as its about to go over the fence.
2.) It can't be radio control, radio waves are easily jammed/over powered, you don't want script kiddies hacking into them either.
3.) Its not like anyone could pilot one via RC and actually hit anything. (Its moving too fast and its hitting too small of a target)
As for building one for less than $1000, right... first off the explosive payload cost alot more than $1000. High frequency/low power video transmitters are pretty much line of sight only, you would have to be able to see the target to get a video signal. Then there is dopplar effect, this thing has to be moving pretty damn fast so no one can shoot it down with a handgun, standard RC equipment mostlikely won't work because the carrier will be shifting due to dopplar effect. GPS isn't much good either, too much error, easily jammed, etc.. Also with radio links your location is a dead give away, soon as you power your transmitter up your dead in a war situation.
If a terrorest wanted to build a cruise missile it would cost alot but its still pretty easy and it wouldn't be RC. For navigation they could simply use any digital signals, cell phones, etc... Dosn't neccessarly have to use GPS. It would simply follow a pre planed route flying fast enough and be small enough to get past defences.
Automated flying is pretty simple, you just program it to keep a steady altiude and heading untill it reaches a waypoint. Autopilot has been around for a long time. Its taking off and landing are the hard parts. In the case of a cruise missile it dosn't have to land, and taking off can be RC.
Another problem with RC planes is that they can't carry any payload, putting a camera and transmitter is a stretch. Explosives are not very light, they require a heavy metal encloser todo any damage(the pressure of the expanding gasses has to build inside first).
As for using off the shelf model rocket motors, the thrust is way too short, model rocket motors only burn for a few seconds at most. They are also pretty heavy for the amount of thrust. It would have to be a liqude fueled motor to have a range of 5 miles. Model jet engions are usually not real jet engions, they are usually ducted fans and are not nearly as fast as a rocket.
For it todo any real damage it has to be faster or almost as fast as sound, if you can hear it comming everyone has time to get away or shoot it down.
So in short, for a guided missle to be effective, it has to be fast, non-RC and carry a good payload.
Artist should have a day job just like the rest of us and art should be a hobby. That way there is no pressure of pop out the crap we see everywhere today.(That includes Paintings, Music, TV, Movies, etc...)
If they are no good at anything else thats what wellfare is for.
Our culture has to get away from the idea that everyone has to work 40 hours a week to live a good life. The fact is that it only takes a small fraction of the population to provide basic services.
Right now technology, construction, cars, etc... are stretching our economy so that most people can work. In the long run the economy as we know it won't last, there is only so much to be built, the limits of technology will be reached, polution will catch up and we will have to stop producing disposables(Cars, sales packaging, home electronics, etc....) Eventually we will reach a point where everything we own will out live us and very little manufactoring will be required.
As education spreads throughout the entire world population growth will slow, stop and start to decreses. Population growth has already leveled off in most of north america.
Another prediction I have is that a world goverment will be formed or the UN will extend its/be given powers to police human rights around the world. The product of this if the formation of an international police force. This international police force will have officers in every city on earth. This police force will have members from all corners of the world and will not show preference to any one culture or country(No American flags, Only the UN). The Americans currently are doing this as vigilaties. This image is diffcult to repair.
Most of this is a long way off but I think I will see it in my life time (I'm only 20 now).
Yikes! Starcraft on a console, those kind of games ususally suck on a console. Thats were the PC rocks. You have dedicated buttons for each unit, way faster than naviagting menus. Then there is the resultion problems. In games like starcraft the more you can see at one time the better. No matter which way you look at it a mouse is far more accurret than a stick for placing buildings.
Anyway... There are two types of gamers, those who just like game play and are happy playing anything from the old nes and snes to the latest xbox games. And then there are people like me who like games that are fast and simulate reality and let me do things I can't do in the real world.(Like going around hunting people in a FPS or Stealing cars and running down police in GTA)
The game play people are happy with the current tech and like consoles because they are simple.
Wireless is fine if your only serving a few customers but once you get over a certain point it becomes very slow.
Wireless is open air is basicly the same thing as cable modems. There is only so much useable bandwidth in the spectrum. Cablemodems are atleast limited to a coax, while wireless can interfear with everything and everything can interfear with it.
Fiber to the home is a long ways off, we need better faster backbones yet. Cable modems and DSL can go faster than the 1mBit that most are capped off at. They are capped because backbones bandwidth is still pretty expensive and untill prices come down from more avaible bandwidth we are not going to seem more than a few mbit to the home.
That said, you will see it in new subdivisions and apartment buildings. Why lay copper and coax when you can just run fiber for the same cost. CPE may cost a little more.
In the mean while wireless is a great way for us Geeks to connect up.
Its always been possible for law enforcement/your ISP to trace back and find out who you are. But its nearly imposible for the average person. So to most other people its impossible to find out who you are online based on an IP or email address.
Basicly you have anonymity to other users/services but not to your ISP and law enforcement(who get the info from the ISP).
Its also no problem to use an assumed idenity online, I use em all the time for sites requiring a name. I also run my email servers so I usually create an alais for each service. This way I can track where the spam is comming from and just delete the alais when there is too much junk comming in.
As for a MAC address giving you away when using an unauthorised network. There is no way to link you to your nic's MAC address unless law enforcement gets a warrent to search your house and todo that they would have to think you did it in the first place.
Just don't leave your wifi nic on at home. They can use direction finding to locate you. Depending on the method used this can take a long time and only give them the general area(say one building or another). Or it could be like GPS in reverse, they could use 3 or more recivers at known locations and they can pin point your location. One trick is to bounce the signal off a large reflector like a building. That would make it almost impossible to track.
The best method of hiding your idenity is to use collage or university networks. At the local university there are public terminals in the commons of the libary, a few hundred. No log in required and alot of them are not on camera. There is also alot of places off camera where you could get at CAT5, splice in, grab the MAC, cut off the destination, clone the mac and your online.
I'm really surprised no one finished the race but from experience I know how tough robotics can be.
A few years ago I was a member of a Highschool robotics team were we build a hockey playing robot one year and a tank the next. They were RC which made is doable but it still was quite challanging.
Robots don't have self preservation instinct and usually end up destroying it self. This seems to be the case in this competition.
When driving a car your not only trying to navigate and not hit people, other cars,etc... Your also trying to not beatup your car. This is a very hard thing to program into a robot. Driving up a rocky hill isn't a simple as taking path with the least rocks in the way, usually its better to find another way around. But in programming how the hell do you tell that its unpassable. A brick wall is easy but a washed out road is hard to determin with cameras and other sensors.
As a human one would get out of their car and walk through before driving. In a race situation you would already know the course and whats passable.
Another challange is sand, its very easy to get stuck and its also hard to tell how deep or lose it is.
In miltary applications you would have detailed aerial photos or beable to take your time so this isn't a realistic test.
I think the next step is to blend all of the above into one game that has fps parts, strategy parts, simulation parts, etc...
Being able to jump into fps mode in a game like GTA3 or starwars galaxies would kick ass. These games already have a bit of simulation in driving cars and speeders.
One cool thing in starwars galaxies is that players can build buildings and stuff to expand the games, its still pretty limited to stock objects and what not. But I think this is the future of games, being able to expand it beyond the orginal concept with out any knowledge of programming.
Starwars galaxies is already a massive-multiplayer game. I just needs a fps mode.
Not true at all, over a distance there can be alot of error in wire transmission. ADSL is a good example of this, with adsl your trying to get alot of signal through unshielded pair, you gota keep the power down to keep it from interfearing with other pairs, you also got alot of noise caused by the other pairs, so you have a low SNR, which these codes can help get alot of data through.
This technique is only for one very small specfic part of the specturm, a communication channel. Communcation channels can very from a few khz in size to a few Mhz, I belive 6Mhz is the biggest which was orginally for TV but channels orginally desinated for TV are not being used for 802.11b and g.
The total spectum goes from 30hz right up past light at some crazy big number. Frequecies below 30Mhz are called HF, these frequceys are pretty full but the total band is only 30 Mhz, thats only 6 TV channels, or alot of small 30khz voice channels. This band is so saturated because its not limited to line of sight and its possible to communicate right around the world on it. Its also the easyest to transmit and recive on because filters for these low frequcencies have very high Q(very narrow bandpass, basicly tune better). At these freq. things are already pretty saturated but are strictly regulated along with most of the spectum up to 300Ghz.
Frequcencys from 30Mhz-1Ghz have been the primary frequecys for local communications for the past 50 years or so. Ever since super-hetrodyning has been around, that allows you to "move" a freq down to a lower intermediated frequecy where you have high Q filters. This range is pretty full too, not much room for new communications, aircraft, broadcast tv and radio, police, cell phones, everything is in this range, old UHF tv channels were resently given up to make room for cellphones. These bands are strickly los, well rf los which is a little better than optical line of sight, lower frequencys refract and difract more than higher frequncy light..
Above 1Ghz has been very expensive to use up untill recently. With the advent of new semiconductors and processes its now viable to use these frequecys. There is lots of bandwidth up here to use, alot of it is tied up in radar and with the miltary which is just legal BS because 99.999% isn't being used. Its more political than techinical. There is also quite a bit of it being wasted by older technology that use like 20Mhz for a 6Mhz signal.
Also alot of companies own rights to these microwave frequenies(above 1Ghz) and have swiched to fiber optics and they are just sitting their idle.
Frequencys above 1Ghz can be used again and a again in diffrent areas provided they are seperated by mountains or the curvature of the earth. The problem with 802.11b is that there are only 3 channels that don't overlap.
Also with frequencys above 1 Ghz you can use a dish to focus the signal in one area rather than using more power in all directions. This way you will only interfear with people using the same frequcys in the direction that your dish is pointing. This flashlight vs a room lamp, the flashlight can light up a small area far away and so can the room lamp, but the room lamp uses more power because it also lights up the full room.
In short there is tones of spectum left, we just need to get some of it back from the military and wasteful users.
Yea I just got back from a lectur where I have edition 5(thats all the collage book store had), most of the class have edition 4 and the instuctor is still giving references to edition 3.
Yagi's are not that effictive at that frequency. Dish's offer anywhere from 18-30dBi and beyond, just build it bigger...
The problem I can see is that I bet their hardware dosn't have an antenna connector, and the antenna is built on. Then you could just put the entire unit at the focal point of the dish.
Another problem people are going to have with this service is that its pretty much strickly line of site, so your going to have to be facing/able to see the tower to get on, even in the 2.5km radius.
Yea, who ever wrote this article has no clue what they are talking about...
Hajimiri's chip runs at 24 GHz (24 billion cycles in one second), an extremely high speed, which makes it possible to transfer data wirelessly at speeds available only to the backbone of the Internet (the main network of connections that carry most of the traffic on the Internet
24GHz is just the operating frequency not the bandwidth. You do have alot of free bandwidth, free is in not sold already, but your still not going to get close to OC-192 speeds. The most rf bandwidth your going to get is maybe 500 Mhz and with 802.11g tech your getting around 20mbit of useable bandwidth out of 6Mhz. So (500/6)*20 = 1666, thats 1.67 gbit, not bad, but nowhere close to backbone speeds of 12gbit.
This technology could replace the dish, but it won't be the size of your thumbnail. A phased array could be used to obtain a fare amount of gain with a 12x12" panel.
Rogers cable here in canada are offering a regular phone that runs over VOIP on their cable system. Soon here in canada we won't have to depend on the telco for land line telephone.
The cost of the electricity to run the CPE is very small, a fraction of whats required to run the average light bulb. They still provide the equipment and maintain/replace the batteries. You currently have to power your DSL or Cablemodem and digital cable box or DSS reciver, all those functions will hopefully be in one box.
As for running out of oil and coal and the cost of electricity increasing... Its not going to happen in the next few years, atleast not here in NL, Canada where the price is regulated and a good persentage of the supply is hydro-electric. The long term cost of electricity won't increase a whole lot in the long run, it will spike during shortages, but new sources such as solar, wind and small scale hydro will become cheaper and will be worth investing in. (IE, buying enough solar panels and batteries to last 30 years will be cheaper than paying todays rate for 30 years). One of the courses I'm studying at collage is Engineering economics and this is the kind of problem I gota teach myself todo tonight... On that thought I better get to studying....
Another way to look at this is that small Copper wires are a very poor at transporting power and alot of it is lost along the lines in heat, in with fiber very little is lost in heat, but you still need to power the electronics on the end which recive power more efficently through high voltage AC transmission. Less power is wasted, less oil and coal are burned.
The router/switch/CPE won't have any user accessable settings, and they will know at the NOC/CO/Headend that your connectivity is gone down before you do. So there is really no need for anyone to call tech support because their phone, internet and cable are gone down. They would already have someone on the problem.
If you unplug the power it will simply switch to backup battery power and warn you from your PC or give you a friendly message on the phone that the power is off and that you should check to make sure that its plugged in if the lights are still on in the house. If you broke/cut/unpluged the fiber they would likely have to send someone out and as I said before they would know before you did.
Also you also still have your cellphone or your neighboors phone to call in.
Not likely 802.11g is very limited to a small number of long range links or alot of small short range links, there are currently only 3 seperate channels, 1 6 and 11, so everyone within range of your AP/client is sharing the bandwidth. Even if they made 2-5 Ghz dedicated to internet you could only get around 90 seperate channels out of it (Ignoring problems with harmonics and what not) or 90*20mbit(pratical.11g bandwidth). 1.8 gigbit, compare that to 2.4gigbit SONET fiber and that can be multiplyed by just adding another cable.
Single mode fiber is very expensive, but multimode fiber can be produced and terminated fairly cheaply. Multimode to home, single mode to the neighberhoor.
I think it will still be owned by the telco or cable co.
Here in canada we have pretty upto date highspeed backbones. DSL is aviable just about everywhere and so is cable internet.
I just heard an annoucement that rogers cable, the largest cable provider in canada is planing on offering telephone service over their cable system.
We currently have a choice for TV, cable(Rogers), or DSS (expressvu(bell/telco partner) or starchoice).
We currently have a choice over internet access, DSL or Cable.
We currently have a choice over cell phones, rogers network or telco network.
So the onlything left is the landline telephone which rogers is moving in on.
I don't think we will see wide spread 10mb or 100mb, fiber to the home in the next decade or so wide spread. The aveage joe is happy with DSL and/or cable. Its just the.001% of us geeks who want more bandwidth...
I think DSS still has a strong future. Put up higher powered birds(no need for dishes, better SNR), with better bandwidth uitilization(use better modulation, like 802.11g), and 500 HD channel universe is possible.
The only way we will see fiber to the home if someone develops a multimode system that is easily terminated, is cheap to buy, tough and that is easy to install. But that still leaves the demand...
The other thing is most people just don't care to pay the extra $$$ for HD tv's, my parents who are only in their early 40's can't tell the quality difference between VHS and DVD's. There is nothing wrong with the fuzzy washed out picture to them. I can't see them going out and buying a HD tv anytime soon, not unless their current one dies and they can't buy anything but HD tv's(ie. stores stop selling regular TV's).
In short the technology should be left to mature before its shoved into the life of the average person, the current local systems (POTS and cable) will serve the needs of average people for a long time yet. Backbones on the other hand should be built and over built untill there is enough bandwidth avaiable for every person in the modern world to have 10mbit of dedicated bandwidth.
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You don't buy a weeks groceries at a time. You buy what you need for today and tomorrow. Then go shopping again in two or three days. If you need to get alot of groceries you call a cab(I don't know about in the big US cities but around here they even help you load and unload the cars).
Most geeks don't like photography, they just like digital stuff and digital cameras are well digital and you can connect them too the computer....
Radio controlled stuff, throw it out the window and control it from the nice airconditioned room.
Crashed firewall? Thats what the intern or MSCE guy is for, call him and tell him what todo.
Lanparties... I'm usually hosting them at my house...
[Serious] Its still april fools somewhere....
The idea is to shoot off a rocket and intercept another rocket or aircraft.
1.) Its like hitting a baseball with a needle as its about to go over the fence.
2.) It can't be radio control, radio waves are easily jammed/over powered, you don't want script kiddies hacking into them either.
3.) Its not like anyone could pilot one via RC and actually hit anything. (Its moving too fast and its hitting too small of a target)
As for building one for less than $1000, right... first off the explosive payload cost alot more than $1000. High frequency/low power video transmitters are pretty much line of sight only, you would have to be able to see the target to get a video signal. Then there is dopplar effect, this thing has to be moving pretty damn fast so no one can shoot it down with a handgun, standard RC equipment mostlikely won't work because the carrier will be shifting due to dopplar effect. GPS isn't much good either, too much error, easily jammed, etc.. Also with radio links your location is a dead give away, soon as you power your transmitter up your dead in a war situation.
If a terrorest wanted to build a cruise missile it would cost alot but its still pretty easy and it wouldn't be RC. For navigation they could simply use any digital signals, cell phones, etc... Dosn't neccessarly have to use GPS. It would simply follow a pre planed route flying fast enough and be small enough to get past defences.
Automated flying is pretty simple, you just program it to keep a steady altiude and heading untill it reaches a waypoint. Autopilot has been around for a long time. Its taking off and landing are the hard parts. In the case of a cruise missile it dosn't have to land, and taking off can be RC.
Another problem with RC planes is that they can't carry any payload, putting a camera and transmitter is a stretch. Explosives are not very light, they require a heavy metal encloser todo any damage(the pressure of the expanding gasses has to build inside first).
As for using off the shelf model rocket motors, the thrust is way too short, model rocket motors only burn for a few seconds at most. They are also pretty heavy for the amount of thrust. It would have to be a liqude fueled motor to have a range of 5 miles. Model jet engions are usually not real jet engions, they are usually ducted fans and are not nearly as fast as a rocket.
For it todo any real damage it has to be faster or almost as fast as sound, if you can hear it comming everyone has time to get away or shoot it down.
So in short, for a guided missle to be effective, it has to be fast, non-RC and carry a good payload.
Its called a day job!
Artist should have a day job just like the rest of us and art should be a hobby. That way there is no pressure of pop out the crap we see everywhere today.(That includes Paintings, Music, TV, Movies, etc...)
If they are no good at anything else thats what wellfare is for.
Our culture has to get away from the idea that everyone has to work 40 hours a week to live a good life. The fact is that it only takes a small fraction of the population to provide basic services.
Right now technology, construction, cars, etc... are stretching our economy so that most people can work. In the long run the economy as we know it won't last, there is only so much to be built, the limits of technology will be reached, polution will catch up and we will have to stop producing disposables(Cars, sales packaging, home electronics, etc....) Eventually we will reach a point where everything we own will out live us and very little manufactoring will be required.
As education spreads throughout the entire world population growth will slow, stop and start to decreses. Population growth has already leveled off in most of north america.
Another prediction I have is that a world goverment will be formed or the UN will extend its/be given powers to police human rights around the world. The product of this if the formation of an international police force. This international police force will have officers in every city on earth. This police force will have members from all corners of the world and will not show preference to any one culture or country(No American flags, Only the UN). The Americans currently are doing this as vigilaties. This image is diffcult to repair.
Most of this is a long way off but I think I will see it in my life time (I'm only 20 now).
Yikes! Starcraft on a console, those kind of games ususally suck on a console. Thats were the PC rocks. You have dedicated buttons for each unit, way faster than naviagting menus. Then there is the resultion problems. In games like starcraft the more you can see at one time the better. No matter which way you look at it a mouse is far more accurret than a stick for placing buildings.
Anyway... There are two types of gamers, those who just like game play and are happy playing anything from the old nes and snes to the latest xbox games. And then there are people like me who like games that are fast and simulate reality and let me do things I can't do in the real world.(Like going around hunting people in a FPS or Stealing cars and running down police in GTA)
The game play people are happy with the current tech and like consoles because they are simple.
Wireless is fine if your only serving a few customers but once you get over a certain point it becomes very slow.
Wireless is open air is basicly the same thing as cable modems. There is only so much useable bandwidth in the spectrum. Cablemodems are atleast limited to a coax, while wireless can interfear with everything and everything can interfear with it.
Fiber to the home is a long ways off, we need better faster backbones yet. Cable modems and DSL can go faster than the 1mBit that most are capped off at. They are capped because backbones bandwidth is still pretty expensive and untill prices come down from more avaible bandwidth we are not going to seem more than a few mbit to the home.
That said, you will see it in new subdivisions and apartment buildings. Why lay copper and coax when you can just run fiber for the same cost. CPE may cost a little more.
In the mean while wireless is a great way for us Geeks to connect up.
Just don't install a cdrom or floppy drive in the machine, or remove them after you install the OS.
I agree with you there.
.
Its always been possible for law enforcement/your ISP to trace back and find out who you are. But its nearly imposible for the average person. So to most other people its impossible to find out who you are online based on an IP or email address.
Basicly you have anonymity to other users/services but not to your ISP and law enforcement(who get the info from the ISP)
Its also no problem to use an assumed idenity online, I use em all the time for sites requiring a name. I also run my email servers so I usually create an alais for each service. This way I can track where the spam is comming from and just delete the alais when there is too much junk comming in.
As for a MAC address giving you away when using an unauthorised network. There is no way to link you to your nic's MAC address unless law enforcement gets a warrent to search your house and todo that they would have to think you did it in the first place.
Just don't leave your wifi nic on at home. They can use direction finding to locate you. Depending on the method used this can take a long time and only give them the general area(say one building or another). Or it could be like GPS in reverse, they could use 3 or more recivers at known locations and they can pin point your location. One trick is to bounce the signal off a large reflector like a building. That would make it almost impossible to track.
The best method of hiding your idenity is to use collage or university networks. At the local university there are public terminals in the commons of the libary, a few hundred. No log in required and alot of them are not on camera. There is also alot of places off camera where you could get at CAT5, splice in, grab the MAC, cut off the destination, clone the mac and your online.
I'm really surprised no one finished the race but from experience I know how tough robotics can be.
A few years ago I was a member of a Highschool robotics team were we build a hockey playing robot one year and a tank the next. They were RC which made is doable but it still was quite challanging.
Robots don't have self preservation instinct and usually end up destroying it self. This seems to be the case in this competition.
When driving a car your not only trying to navigate and not hit people, other cars,etc... Your also trying to not beatup your car. This is a very hard thing to program into a robot. Driving up a rocky hill isn't a simple as taking path with the least rocks in the way, usually its better to find another way around. But in programming how the hell do you tell that its unpassable. A brick wall is easy but a washed out road is hard to determin with cameras and other sensors.
As a human one would get out of their car and walk through before driving. In a race situation you would already know the course and whats passable.
Another challange is sand, its very easy to get stuck and its also hard to tell how deep or lose it is.
In miltary applications you would have detailed aerial photos or beable to take your time so this isn't a realistic test.
I think the next step is to blend all of the above into one game that has fps parts, strategy parts, simulation parts, etc...
Being able to jump into fps mode in a game like GTA3 or starwars galaxies would kick ass. These games already have a bit of simulation in driving cars and speeders.
One cool thing in starwars galaxies is that players can build buildings and stuff to expand the games, its still pretty limited to stock objects and what not. But I think this is the future of games, being able to expand it beyond the orginal concept with out any knowledge of programming.
Starwars galaxies is already a massive-multiplayer game. I just needs a fps mode.
Not true at all, over a distance there can be alot of error in wire transmission. ADSL is a good example of this, with adsl your trying to get alot of signal through unshielded pair, you gota keep the power down to keep it from interfearing with other pairs, you also got alot of noise caused by the other pairs, so you have a low SNR, which these codes can help get alot of data through.
This technique is only for one very small specfic part of the specturm, a communication channel. Communcation channels can very from a few khz in size to a few Mhz, I belive 6Mhz is the biggest which was orginally for TV but channels orginally desinated for TV are not being used for 802.11b and g.
The total spectum goes from 30hz right up past light at some crazy big number. Frequecies below 30Mhz are called HF, these frequceys are pretty full but the total band is only 30 Mhz, thats only 6 TV channels, or alot of small 30khz voice channels. This band is so saturated because its not limited to line of sight and its possible to communicate right around the world on it. Its also the easyest to transmit and recive on because filters for these low frequcencies have very high Q(very narrow bandpass, basicly tune better). At these freq. things are already pretty saturated but are strictly regulated along with most of the spectum up to 300Ghz.
Frequcencys from 30Mhz-1Ghz have been the primary frequecys for local communications for the past 50 years or so. Ever since super-hetrodyning has been around, that allows you to "move" a freq down to a lower intermediated frequecy where you have high Q filters. This range is pretty full too, not much room for new communications, aircraft, broadcast tv and radio, police, cell phones, everything is in this range, old UHF tv channels were resently given up to make room for cellphones. These bands are strickly los, well rf los which is a little better than optical line of sight, lower frequencys refract and difract more than higher frequncy light..
Above 1Ghz has been very expensive to use up untill recently. With the advent of new semiconductors and processes its now viable to use these frequecys. There is lots of bandwidth up here to use, alot of it is tied up in radar and with the miltary which is just legal BS because 99.999% isn't being used. Its more political than techinical. There is also quite a bit of it being wasted by older technology that use like 20Mhz for a 6Mhz signal.
Also alot of companies own rights to these microwave frequenies(above 1Ghz) and have swiched to fiber optics and they are just sitting their idle.
Frequencys above 1Ghz can be used again and a again in diffrent areas provided they are seperated by mountains or the curvature of the earth. The problem with 802.11b is that there are only 3 channels that don't overlap.
Also with frequencys above 1 Ghz you can use a dish to focus the signal in one area rather than using more power in all directions. This way you will only interfear with people using the same frequcys in the direction that your dish is pointing. This flashlight vs a room lamp, the flashlight can light up a small area far away and so can the room lamp, but the room lamp uses more power because it also lights up the full room.
In short there is tones of spectum left, we just need to get some of it back from the military and wasteful users.
Yep, it has been, thats what adsl uses I belive...
Yea I just got back from a lectur where I have edition 5(thats all the collage book store had), most of the class have edition 4 and the instuctor is still giving references to edition 3.
Yagi's are not that effictive at that frequency. Dish's offer anywhere from 18-30dBi and beyond, just build it bigger...
The problem I can see is that I bet their hardware dosn't have an antenna connector, and the antenna is built on. Then you could just put the entire unit at the focal point of the dish.
Another problem people are going to have with this service is that its pretty much strickly line of site, so your going to have to be facing/able to see the tower to get on, even in the 2.5km radius.
So what if the network is insecure? So is the internet...
Who cares if your neighboors can tell your reading slashdot or searching on google. They can look in the window to find that stuff out.
Private emails should be encrypted anyway, same goes for online banking and stuff...
"man-in-the-middle attacks" What would they be attacking?
Yea, who ever wrote this article has no clue what they are talking about...
Hajimiri's chip runs at 24 GHz (24 billion cycles in one second), an extremely high speed, which makes it possible to transfer data wirelessly at speeds available only to the backbone of the Internet (the main network of connections that carry most of the traffic on the Internet
24GHz is just the operating frequency not the bandwidth. You do have alot of free bandwidth, free is in not sold already, but your still not going to get close to OC-192 speeds. The most rf bandwidth your going to get is maybe 500 Mhz and with 802.11g tech your getting around 20mbit of useable bandwidth out of 6Mhz. So (500/6)*20 = 1666, thats 1.67 gbit, not bad, but nowhere close to backbone speeds of 12gbit.
This technology could replace the dish, but it won't be the size of your thumbnail. A phased array could be used to obtain a fare amount of gain with a 12x12" panel.
Better yet store them in ram... Deleted logs can be recovered...
VOIP is just another technology for voice communication like two cans and a string, two way radio and POTS.
I think what they mean is that if a VOIP system is connected to the publicly switched telephone network they must give access to local 911...
Here in canada rogers cable is offering telephone lines using VOIP on their cable system. I sure hope they offer access to the local 911...
VOIP dosn't mean computer...
Rogers cable here in canada are offering a regular phone that runs over VOIP on their cable system. Soon here in canada we won't have to depend on the telco for land line telephone.
The cost of the electricity to run the CPE is very small, a fraction of whats required to run the average light bulb. They still provide the equipment and maintain/replace the batteries. You currently have to power your DSL or Cablemodem and digital cable box or DSS reciver, all those functions will hopefully be in one box.
As for running out of oil and coal and the cost of electricity increasing... Its not going to happen in the next few years, atleast not here in NL, Canada where the price is regulated and a good persentage of the supply is hydro-electric. The long term cost of electricity won't increase a whole lot in the long run, it will spike during shortages, but new sources such as solar, wind and small scale hydro will become cheaper and will be worth investing in. (IE, buying enough solar panels and batteries to last 30 years will be cheaper than paying todays rate for 30 years). One of the courses I'm studying at collage is Engineering economics and this is the kind of problem I gota teach myself todo tonight... On that thought I better get to studying....
Another way to look at this is that small Copper wires are a very poor at transporting power and alot of it is lost along the lines in heat, in with fiber very little is lost in heat, but you still need to power the electronics on the end which recive power more efficently through high voltage AC transmission. Less power is wasted, less oil and coal are burned.
The router/switch/CPE won't have any user accessable settings, and they will know at the NOC/CO/Headend that your connectivity is gone down before you do. So there is really no need for anyone to call tech support because their phone, internet and cable are gone down. They would already have someone on the problem.
If you unplug the power it will simply switch to backup battery power and warn you from your PC or give you a friendly message on the phone that the power is off and that you should check to make sure that its plugged in if the lights are still on in the house. If you broke/cut/unpluged the fiber they would likely have to send someone out and as I said before they would know before you did.
Also you also still have your cellphone or your neighboors phone to call in.
Not likely 802.11g is very limited to a small number of long range links or alot of small short range links, there are currently only 3 seperate channels, 1 6 and 11, so everyone within range of your AP/client is sharing the bandwidth. Even if they made 2-5 Ghz dedicated to internet you could only get around 90 seperate channels out of it (Ignoring problems with harmonics and what not) or 90*20mbit(pratical .11g bandwidth). 1.8 gigbit, compare that to 2.4gigbit SONET fiber and that can be multiplyed by just adding another cable.
Single mode fiber is very expensive, but multimode fiber can be produced and terminated fairly cheaply. Multimode to home, single mode to the neighberhoor.
Rogers cable here in Canada are about to launch a telephone system over their cable systems.
As part of the CPE they suppy a UPS so the system will still work for some time when the power goes out.
I think it will still be owned by the telco or cable co.
.001% of us geeks who want more bandwidth...
Here in canada we have pretty upto date highspeed backbones. DSL is aviable just about everywhere and so is cable internet.
I just heard an annoucement that rogers cable, the largest cable provider in canada is planing on offering telephone service over their cable system.
We currently have a choice for TV, cable(Rogers), or DSS (expressvu(bell/telco partner) or starchoice).
We currently have a choice over internet access, DSL or Cable.
We currently have a choice over cell phones, rogers network or telco network.
So the onlything left is the landline telephone which rogers is moving in on.
I don't think we will see wide spread 10mb or 100mb, fiber to the home in the next decade or so wide spread. The aveage joe is happy with DSL and/or cable. Its just the
I think DSS still has a strong future. Put up higher powered birds(no need for dishes, better SNR), with better bandwidth uitilization(use better modulation, like 802.11g), and 500 HD channel universe is possible.
The only way we will see fiber to the home if someone develops a multimode system that is easily terminated, is cheap to buy, tough and that is easy to install. But that still leaves the demand...
The other thing is most people just don't care to pay the extra $$$ for HD tv's, my parents who are only in their early 40's can't tell the quality difference between VHS and DVD's. There is nothing wrong with the fuzzy washed out picture to them. I can't see them going out and buying a HD tv anytime soon, not unless their current one dies and they can't buy anything but HD tv's(ie. stores stop selling regular TV's).
In short the technology should be left to mature before its shoved into the life of the average person, the current local systems (POTS and cable) will serve the needs of average people for a long time yet. Backbones on the other hand should be built and over built untill there is enough bandwidth avaiable for every person in the modern world to have 10mbit of dedicated bandwidth.