Um, 802.11 devices are, by definition, duplex. In other words, in order to actually establish a link, every node has to be both transmitting and receiving. One that acted as a receive only device wouldn't do anything useful (except to eavesdroppers). That said, violations of Part 15 rules are beyond the scope of the local PD, and the FCC is unlikely to pursue the matter unless they receive complaints of interference related to your transmissions.
H.264? Pah. Raw SMPTE-292M videoconferencing is where it's at - all you need is a bunch of incredibly expensive equipment and a network capable of sustained 1.5 Gb/s. Each way.
Wind deflection can be a problem - they design dishes so they can be bolted down. Also, you'll notice that most home installers mount the dish so that the building itself affords some wind protection. Big dishes weigh several tons, and are very well secured. The ones that are truly vulnerable are the truck mounted dishes - they can and do get knocked off a satellite by wind gusts.
Well, there are web sites that allow you to enter your latitude and longitude and the orbital slot of a satellite, and then they do the math for you to get the azimuth and elevation. Or if you're a math geek, you can do the math yourself. Then, if you had an extremely accurate compass/inclinometer you could try to aim the antenna that way. In actual practice, I doubt that would work reliably - hitting a target the size of a car from 22,000 miles away is a very touchy business. Most pros use a compass/inclinometer to get to the right portion of the sky, and then hook up a spectrum analyzer to find the nearest satellite, and then 'stair step' across the arc until they find the bird they want. Being able to ID a satellite by its spectrum plot is a little bit of an art, but allows you to at least confirm that you're looking at a satellite. You can always hook up your IRD at that point to check of it's the right satellite. The problem with just tuning using your receiver on a digital signal, is that below a certain threshold the signal will not lock up, so be prepared to spend all day moving your dish 1/4 of a degree at a time, and waiting 30 seconds after each move to see if it locks up.
Ironically, the smaller dishes are easier to aim, since their gain is so much lower. Remember, a satellite dish is simply a telescope that operates on microwave frequencies rather than visible light, so a more powerful antenna "sees" a much smaller portion of sky, and consequently gets a much better signal. Having aligned 1.6-meter dishes and 12-meter dishes, I can attest that the 12-meter gets a great signal, but is harder to aim.
No, Phillips left the field and moved to Colorado. Lai remains at the UW as a Research Professor with the Bioengineering department. Lai was the one, however, who stopped using a cell phone and requested that family members use headsets.
The thing I don't understand about this whole debate is this: when a scientist discovers something alarming about a commonly used technology, it's understood that further investigation could reveal that it's not actually dangerous or that the effects can be easily mitigated - the point is that it's supposed to spur further research. It's this thing we have called scientific investigation. When an industry that profits from the technology in question jumps in and starts trying to buy favorable findings, then that is truly a cause for alarm. I don't understand why people become hostile towards research that indicates that the cell phone they find so convenient may actually be killing them. Does this fall into the category of 'see no evil, hear no evil'?
There was something similar when the news station I used to work for switched from Beta SP to Beta SX for acquisition - Sony pitched their very expensive SX tapes (with a 'special' yellow shell), but we quickly realized that any old SP tape would work just fine. In fact using an SP tape meant you got double the recording time (SX used a slower tape speed). I expect that this is mostly a case of JVC trying to make money wherever they can. Of course, there are differences in tape stock (thickness of the tape itself, oxide density, particle size, etc) so they could also be trying to limit calls from angry customers who try to use some crap tape they picked up at a garage sale that had already been recorded over a couple of dozen times.
The article refers to comments made by one of the judges in the case and NOT to a ruling. The court still has to determine if the complaintants have standing to bring this case, and if not, then the whole case gets thrown out.
From the article:
The appeals panel now has to decide whether consumer groups which are criticising the rule should have the right to contest the FCC's requirements.
The case could be thrown out of the appeals court if it decides they do not have the right to lawfully challenge the FCC decision. A decision by the court is expected within months.
Sounds like sloppy reporting from news.com - check out the Reuters story.
And, just to add a voice to the fugue, there is no way in hell I would consider buying this product. First off, their press release is filled with marketspeak lies: "price undercuts a 40GB iPod!!" (er, actually their unit only has half the storage but they encoded the songs at 48Kb/s and compared it against Apple's standard bitrate of 128Kb/s so they could claim that it fits more songs and hope idiot consumers won't figure that out.) "will play MP3, WMA and WAV!!" (actually, it only plays ATRAC3 and you have to use their proprietary, buggy software to make a copy of your entire collection using ATRAC3 before loading it onto the device. BTW, this process could take hours.) "ATRAC3 sounds better than MP3!!" (according to their VP of Marketing's 5 year old nephew, at least, though there are a lot nuts out there doing double-blind listening tests which show that ATRAC3 is the worst audio CODEC out there, even at 128Kb/s never mind the fact that Sony assumed 48Kb/s encoding in order to make their ridiculous capacity comparison to the 40GB iPod.)
So. To sum up: decent ergonomics, no real price advantage in an apples to apples comparison (no pun intended), only supports a crappy DRM'd Sony format. Read this Wired article on why Sony sucks, and why you shouldn't buy anything from them until they get their head out of their asses and start making things their customers actually want.
No, region coding is the problem. PAL/NTSC/SECAM are all ANALOG video standards which mainly have to do with chrominance encoding, number of lines and frame rate. Once the analog to digital conversion occurs, the chroma encoding difference goes away, since MPEG-2 is MPEG-2. This means that the only differences between a PAL and NTSC DVD are: the number of active lines (480 vs 576) and the frame rate (29.97 vs. 25) - the line difference is handled automatically in the decoding process by most DACs - they output whatever your display can accept - while the frame rate difference results, at worst, in a little skip every so often. And for a practical demonstration of the above theory, ask anyone who's taken an off-the-shelf DVD player with hackable firmware (though lord knows I'm not advocating any such thing. That would be illegal) and upgraded to a R0 player. IT WORKS FINE. I suspect most hardware manufacturers use an MPEG-2 implementation that supports multi-format playback in the secret hope that one day region coding will go away.
Teledesic didn't work because it was INSANELY EXPENSIVE. I mean, their original plan called for something like 480 satellites in a low Earth orbit. Then they scaled it back to two hundred or so satellites with reduced functionality and coverage. And then, shortly before they withered away, they were saying something about *maybe* a dozen satellites in a higher orbit with even less coverage. I think at that point they looked at the plan and said: "Oh shit, this has been done before and it was called Iridium"
Heh - I was about to submit this story. I can add a link to the actual bill, though: H.R. 2735. And, if you happen to be a US voter reading this, go here, find your representatives, and tell them that you support the Motor Vehicle Owners' Right to Repair Act of 2003. Perhaps hint to them that the same rationale could be applied to other things that consumers buy, and might want to fix at some point. Perhaps suggest that, really, some sort of comprehensive Consumers Bill of Rights could be in order. Just a thought.
It annoys me that I wasted time trying to decide if the original article was genuine, but wrong or a case of the writer lying because they thought that was funny. It's not even April yet!
Amazing how you and many others assume that most MBA's are idiots and just out for money and will do anything illegal to get there.
Not idiots, just felons.
Seriously though, I think the business climate in the US led a lot of greedy assholes with 'negotiable' morals and the ability to rationalize just about anything to see an MBA as a quick ticket to the big bucks. They were probably right - if for no other reason than that once you get a few like that in power, they tend to perpetuate the climate. Having seen a constant parade of these types come through my office; managers who don't give a rat's ass for the company's long term viability and from whom the phrase "enhancing shareholder value" should, in a perfect world, be accompanied by drooling and smacking of lips, I find the idea of working for a common mugger to be more appetizing. Yes, there are plenty of good, honest MBAs who see their role as that of stewards of their business, building something that will outlast their own tenure, and presiding over the creation of products that enhance the marketplace and jobs that strengthen the community. And if you ever meet one of these, please send me their picture, as I wish to hang it on my wall in a little shrine of some sort.
Sometimes you need to be more worried about the owner of the ATM. MSNBC did an investigation of felons owning legitimate ATM machines a while back. So, yes, do be afraid of those little corner market machines.
MBco does not appear to have published EIRP numbers for this satellite, nor have I seen gain figures for the type of antenna that would be deployed in the receivers, so putting together a link budget is out of the question. Here's what we do know: the satellite is a modified SS/L three-axis, body-stabilized 1300 bus. The modifications include a 12-meter antenna reflector deployed in orbit to transmit the MBC programming. Each of the 16 channels has 120W of power, which adds up to a massive EIRP. Also, figure that the antenna is shaped into a spot beam to concentrate most of the signal on Japan. Modulation is CDM (code division multiplex) with Reed-Solomon convolutional coding for error correction. The point being that I have to have a certain amount of faith that a consortium of companies such as Toyota, Toshiba, Fujitsu, Panasonic and Nippon TV (among others) are not going to launch a $50 Million satellite if they haven't done some basic research into whether it's going to work. You can check out MBco's site if you want more info.
The reason for the small number of channels isn't because of the frequency used, it's because of the bandwidth allocated: conventional C-, Ka- or Ku-band satellites operate with 500MHz of bandwidth (or more), but the MBSat will only be using 25MHz of bandwidth in the S-band. They will apparently be using MPEG-4 compression to get even that many channels to fit. Go here and grep for "mbsat" to find more technical info. My only concern with this sort of scheme would be terrestrial interference - I mean, 2.6GHz is awfully close to existing Rf allocations and they will be transmitting with a large amount of power to get a signal to tiny little cell phone antennas. Though it would be funny if they put a system like this over North America - certain lunatics would have a panic attack.
The $275 non-refundable portion does not seem reasonable under the FCC's definitions. Here is the actual FCC information on the subject. One huge problem with the FCC rules when it comes to satellite reception is that they only preserve your right to place antennas on property you directly control, which means that if you only have windows or balconies that face North, or if you have Southern exposure, but there are obstructions that prevent you from seeing the satellite, then you're out of luck.
Hmmm... I've had rain fade on a 5.6 meter dish that was thoroughly peaked and nulled. I could literally look outside at a big, fat cloud moving across the sky and then look inside at my spectrum monitor and watch everything on the satellite drop 10dB in a matter of seconds. If there is enough water in the path, a Ku signal will die, and there's nothing to be done except wait for the weather to improve.
It is in the Ku band (14-14.5 GHz up/11.7-12.2 GHz down). I would tend to disagree with the parent poster - the path attenuation on a CLEAR day can be on the order of 200dB each way, and atmospheric moisture over either your antenna or the SOC's antennas can screw your link budget no matter how dry your antenna is.
All you need is a big old satellite antenna, a spectrum analyzer, a frequency generator capable of tuning to a stable 6 or 14 GHz (C or Ku) signal, an amplifier capable of amplifying that kind of signal up to about 100 watts, some waveguide... hmmm. It would probably also help to have a fast car for when the FCC arrives 30 minutes later.
This is sort of like saying that flying to the moon is easy - all you need is a big metal tube and some propellant.
Reminds me of the story (urban legend?) that goes around about the engineers who take key systems down for "routine maintenance" just before walking out - to make sure the managers can't run the shop. Of course, this won't exactly help you get a new job.
Actually, this raises a serious point, which is that a departmental walkout may give you visceral satisfaction, but most technical industries have a 'grapevine' of some sort. You could find yourself interviewing for a new job and having the interviewer say: "Oh, you're one of THOSE guys..."
Unless you have another job lined up, or know that there are lots of better places with openings, it's probably a good idea to stick with the devil you do know.
CRT's (Cathode Ray Tubes) direct a beam of electrons at a thin layer of phosphor which coats the screen on your monitor. When the electrons strike the phosphor, shadow mask and other screen components, x-rays are produced. The amount and energy of the x-rays depends on the accelerating voltage. The relatively low voltages in CRT's (compared to commercial x-ray machines) means that relatively low quantities of low energy x-rays are produced and modern monitors are so well shielded, that there is no concern of being irradiated over time. Though it is possible for a damaged monitor to emit x-ray radiation, it is unlikely that harmful amounts will be released, and most x-rays would be directed towards the back or sides of the monitor. Any damage to the front of the CRT severe enough to increase x-ray emission would cause the CRT to implode.
The article did say live broadcast quality transmission. Looking at one of the manufacturer's sites (Swe-Dish) though, they mention their max data rate as being 2Mbps - which is under "standard" SNG digital video rates (ABC ABSAT, for example, uses 5.5Mbps) by a little. Of course, you can improve the signal by using more aggressive compression, but that's usually at the cost of heavier hardware demands and higher encoding latency, so you'll end up with the reporter staring at the camera for several seconds before responding to the anchor. Bottom line - this stuff is really cool and is definitely the trend to watch, but the networks aren't going to run out and sell their satellite trucks right away.
Slashdot Mirror
Um, 802.11 devices are, by definition, duplex. In other words, in order to actually establish a link, every node has to be both transmitting and receiving. One that acted as a receive only device wouldn't do anything useful (except to eavesdroppers). That said, violations of Part 15 rules are beyond the scope of the local PD, and the FCC is unlikely to pursue the matter unless they receive complaints of interference related to your transmissions.
H.264? Pah. Raw SMPTE-292M videoconferencing is where it's at - all you need is a bunch of incredibly expensive equipment and a network capable of sustained 1.5 Gb/s. Each way.
Wind deflection can be a problem - they design dishes so they can be bolted down. Also, you'll notice that most home installers mount the dish so that the building itself affords some wind protection. Big dishes weigh several tons, and are very well secured. The ones that are truly vulnerable are the truck mounted dishes - they can and do get knocked off a satellite by wind gusts.
Ironically, the smaller dishes are easier to aim, since their gain is so much lower. Remember, a satellite dish is simply a telescope that operates on microwave frequencies rather than visible light, so a more powerful antenna "sees" a much smaller portion of sky, and consequently gets a much better signal. Having aligned 1.6-meter dishes and 12-meter dishes, I can attest that the 12-meter gets a great signal, but is harder to aim.
The thing I don't understand about this whole debate is this: when a scientist discovers something alarming about a commonly used technology, it's understood that further investigation could reveal that it's not actually dangerous or that the effects can be easily mitigated - the point is that it's supposed to spur further research. It's this thing we have called scientific investigation. When an industry that profits from the technology in question jumps in and starts trying to buy favorable findings, then that is truly a cause for alarm. I don't understand why people become hostile towards research that indicates that the cell phone they find so convenient may actually be killing them. Does this fall into the category of 'see no evil, hear no evil'?
There was something similar when the news station I used to work for switched from Beta SP to Beta SX for acquisition - Sony pitched their very expensive SX tapes (with a 'special' yellow shell), but we quickly realized that any old SP tape would work just fine. In fact using an SP tape meant you got double the recording time (SX used a slower tape speed). I expect that this is mostly a case of JVC trying to make money wherever they can. Of course, there are differences in tape stock (thickness of the tape itself, oxide density, particle size, etc) so they could also be trying to limit calls from angry customers who try to use some crap tape they picked up at a garage sale that had already been recorded over a couple of dozen times.
The article refers to comments made by one of the judges in the case and NOT to a ruling. The court still has to determine if the complaintants have standing to bring this case, and if not, then the whole case gets thrown out.
From the article:
And, just to add a voice to the fugue, there is no way in hell I would consider buying this product. First off, their press release is filled with marketspeak lies: "price undercuts a 40GB iPod!!" (er, actually their unit only has half the storage but they encoded the songs at 48Kb/s and compared it against Apple's standard bitrate of 128Kb/s so they could claim that it fits more songs and hope idiot consumers won't figure that out.) "will play MP3, WMA and WAV!!" (actually, it only plays ATRAC3 and you have to use their proprietary, buggy software to make a copy of your entire collection using ATRAC3 before loading it onto the device. BTW, this process could take hours.) "ATRAC3 sounds better than MP3!!" (according to their VP of Marketing's 5 year old nephew, at least, though there are a lot nuts out there doing double-blind listening tests which show that ATRAC3 is the worst audio CODEC out there, even at 128Kb/s never mind the fact that Sony assumed 48Kb/s encoding in order to make their ridiculous capacity comparison to the 40GB iPod.)
So. To sum up: decent ergonomics, no real price advantage in an apples to apples comparison (no pun intended), only supports a crappy DRM'd Sony format. Read this Wired article on why Sony sucks, and why you shouldn't buy anything from them until they get their head out of their asses and start making things their customers actually want.
1. Find a website for a product/phenomenon with a rabid fan base which gives points for referrals.
2. Post a link that credits your profile for each clickthru on slashdot..
3. ??????
4. Profit!
Ooh, I thought you were talking about the Librarian from Halo. The one that turns out to be evil and tries to kill you.
No, region coding is the problem. PAL/NTSC/SECAM are all ANALOG video standards which mainly have to do with chrominance encoding, number of lines and frame rate. Once the analog to digital conversion occurs, the chroma encoding difference goes away, since MPEG-2 is MPEG-2. This means that the only differences between a PAL and NTSC DVD are: the number of active lines (480 vs 576) and the frame rate (29.97 vs. 25) - the line difference is handled automatically in the decoding process by most DACs - they output whatever your display can accept - while the frame rate difference results, at worst, in a little skip every so often. And for a practical demonstration of the above theory, ask anyone who's taken an off-the-shelf DVD player with hackable firmware (though lord knows I'm not advocating any such thing. That would be illegal) and upgraded to a R0 player. IT WORKS FINE. I suspect most hardware manufacturers use an MPEG-2 implementation that supports multi-format playback in the secret hope that one day region coding will go away.
Teledesic didn't work because it was INSANELY EXPENSIVE. I mean, their original plan called for something like 480 satellites in a low Earth orbit. Then they scaled it back to two hundred or so satellites with reduced functionality and coverage. And then, shortly before they withered away, they were saying something about *maybe* a dozen satellites in a higher orbit with even less coverage. I think at that point they looked at the plan and said: "Oh shit, this has been done before and it was called Iridium"
Heh - I was about to submit this story. I can add a link to the actual bill, though: H.R. 2735. And, if you happen to be a US voter reading this, go here, find your representatives, and tell them that you support the Motor Vehicle Owners' Right to Repair Act of 2003. Perhaps hint to them that the same rationale could be applied to other things that consumers buy, and might want to fix at some point. Perhaps suggest that, really, some sort of comprehensive Consumers Bill of Rights could be in order. Just a thought.
It annoys me that I wasted time trying to decide if the original article was genuine, but wrong or a case of the writer lying because they thought that was funny. It's not even April yet!
Not idiots, just felons.
Seriously though, I think the business climate in the US led a lot of greedy assholes with 'negotiable' morals and the ability to rationalize just about anything to see an MBA as a quick ticket to the big bucks. They were probably right - if for no other reason than that once you get a few like that in power, they tend to perpetuate the climate. Having seen a constant parade of these types come through my office; managers who don't give a rat's ass for the company's long term viability and from whom the phrase "enhancing shareholder value" should, in a perfect world, be accompanied by drooling and smacking of lips, I find the idea of working for a common mugger to be more appetizing. Yes, there are plenty of good, honest MBAs who see their role as that of stewards of their business, building something that will outlast their own tenure, and presiding over the creation of products that enhance the marketplace and jobs that strengthen the community. And if you ever meet one of these, please send me their picture, as I wish to hang it on my wall in a little shrine of some sort.
Bitter? Maybe a little. Wrong? Prove it.
Sometimes you need to be more worried about the owner of the ATM. MSNBC did an investigation of felons owning legitimate ATM machines a while back. So, yes, do be afraid of those little corner market machines.
MBco does not appear to have published EIRP numbers for this satellite, nor have I seen gain figures for the type of antenna that would be deployed in the receivers, so putting together a link budget is out of the question. Here's what we do know: the satellite is a modified SS/L three-axis, body-stabilized 1300 bus. The modifications include a 12-meter antenna reflector deployed in orbit to transmit the MBC programming. Each of the 16 channels has 120W of power, which adds up to a massive EIRP. Also, figure that the antenna is shaped into a spot beam to concentrate most of the signal on Japan. Modulation is CDM (code division multiplex) with Reed-Solomon convolutional coding for error correction. The point being that I have to have a certain amount of faith that a consortium of companies such as Toyota, Toshiba, Fujitsu, Panasonic and Nippon TV (among others) are not going to launch a $50 Million satellite if they haven't done some basic research into whether it's going to work. You can check out MBco's site if you want more info.
The reason for the small number of channels isn't because of the frequency used, it's because of the bandwidth allocated: conventional C-, Ka- or Ku-band satellites operate with 500MHz of bandwidth (or more), but the MBSat will only be using 25MHz of bandwidth in the S-band. They will apparently be using MPEG-4 compression to get even that many channels to fit. Go here and grep for "mbsat" to find more technical info. My only concern with this sort of scheme would be terrestrial interference - I mean, 2.6GHz is awfully close to existing Rf allocations and they will be transmitting with a large amount of power to get a signal to tiny little cell phone antennas. Though it would be funny if they put a system like this over North America - certain lunatics would have a panic attack.
The $275 non-refundable portion does not seem reasonable under the FCC's definitions. Here is the actual FCC information on the subject. One huge problem with the FCC rules when it comes to satellite reception is that they only preserve your right to place antennas on property you directly control, which means that if you only have windows or balconies that face North, or if you have Southern exposure, but there are obstructions that prevent you from seeing the satellite, then you're out of luck.
Hmmm... I've had rain fade on a 5.6 meter dish that was thoroughly peaked and nulled. I could literally look outside at a big, fat cloud moving across the sky and then look inside at my spectrum monitor and watch everything on the satellite drop 10dB in a matter of seconds. If there is enough water in the path, a Ku signal will die, and there's nothing to be done except wait for the weather to improve.
It is in the Ku band (14-14.5 GHz up/11.7-12.2 GHz down). I would tend to disagree with the parent poster - the path attenuation on a CLEAR day can be on the order of 200dB each way, and atmospheric moisture over either your antenna or the SOC's antennas can screw your link budget no matter how dry your antenna is.
DSL Reports maintains a DirecWay forum as well.
All you need is a big old satellite antenna, a spectrum analyzer, a frequency generator capable of tuning to a stable 6 or 14 GHz (C or Ku) signal, an amplifier capable of amplifying that kind of signal up to about 100 watts, some waveguide... hmmm. It would probably also help to have a fast car for when the FCC arrives 30 minutes later.
This is sort of like saying that flying to the moon is easy - all you need is a big metal tube and some propellant.
Reminds me of the story (urban legend?) that goes around about the engineers who take key systems down for "routine maintenance" just before walking out - to make sure the managers can't run the shop. Of course, this won't exactly help you get a new job.
Actually, this raises a serious point, which is that a departmental walkout may give you visceral satisfaction, but most technical industries have a 'grapevine' of some sort. You could find yourself interviewing for a new job and having the interviewer say: "Oh, you're one of THOSE guys..."
Unless you have another job lined up, or know that there are lots of better places with openings, it's probably a good idea to stick with the devil you do know.
My $.02
The article did say live broadcast quality transmission. Looking at one of the manufacturer's sites (Swe-Dish) though, they mention their max data rate as being 2Mbps - which is under "standard" SNG digital video rates (ABC ABSAT, for example, uses 5.5Mbps) by a little. Of course, you can improve the signal by using more aggressive compression, but that's usually at the cost of heavier hardware demands and higher encoding latency, so you'll end up with the reporter staring at the camera for several seconds before responding to the anchor. Bottom line - this stuff is really cool and is definitely the trend to watch, but the networks aren't going to run out and sell their satellite trucks right away.