"Someone please explain how a virus can update a Skype user's telephone book? Seems like a poorly-designed software that allows voice telephone messages to modify its database."
Easy. The skype user's telephone book is most likely (I don't use Skype so I can't be sure) a file on their PC.
A virus can enter that PC in any of the normal ways that they can propagate and go modify that file. (i.e. it isn't a "VoIP Virus", it's a traditional virus that attacks your address book once you're infected)
While my bank has quite a few online services, it appears that many require a phone call or in-person visit.
Of course, since my bank has a branch office right next to my company's cafeteria, I don't consider this an issue.:)
I don't store numbers in any address book that are on websites I frequently use, this includes all of my banks. (100% of phone calls to the bank are usually the result of a "you can't do this online, call 1-800-xyz-abcd".
Um, you really have your estimates of difficulty way off.
With the exception of the electronics (which are extremely simple, USB HID devices can be implemented in a $5-8 Atmel AVR chip which is still available in DIP packaging on a single-layer single-side circuit board), nothing needed to make a high-quality dance pad (at least in terms of tools, some of the specialty materials might need to be sourced elsewhere) can't be bought at your local Lowes or Home Depot.
On the other hand, equipment to produce a multilayer PCB or solder BGA ICs (which basically require using solder reflow techniques) is far harder and more expensive to obtain.
Yes, you can do reflow soldering with a skillet or toaster oven, but it's not the sort of thing I'd ever consider for anything but "personal use" one-off projects. Multilayer PCBs - to my knowledge there is no way to DIY them.
Yes, the DDR dance pads may be labor intensive, but they are not capital-intensive. Thus the price of the dance pads doesn't change much with volume, where as the cost of a custom motherboard for a modern computer would be thousands of dollars per unit in small quantities due to the initial capital expenditure needed.
Simple. They have not patented Bluetooth or anything related to the protocol itself, but have patented a specific way of designing an RF receiver.
That specific way is not specified in the Bluetooth protocol.
Also, this patent isn't limited in any way to Bluetooth only. It can be applied to any RF receiver that is designed in a similar way for any protocol.
Likewise, a Bluetooth chipset manufacturer can choose a receiver architecture that doesn't infringe on this patent. It just may suffer from reduced performance or increased cost. I haven't had time to read the details of the patent, but from what I've seen and other have said, the patent is on a method of implementing an RF receiver in silicon that reduces the number of external analog components needed (and hence the cost) without a significant negative impact on performance.
Whoever submitted the article was an idiot. There is nothing Bluetooth-specific about these patents, and you can't sell a patent under a brand name.
You can sell (or give) ownership of a patent to another entity You can license the right to use the patent to another entity
I would need to read the patent more to comment on it, but while the individual techniques are all well-known, the architecture of the whole receiver seems to be what this covers.
To me it looks like a very narrow patent, it would be extremely difficult to prove that an IC used this particular architecture, and would be reasonably easy to work around I think.
Sort of like how no one can patent a wheel (prior art) or a tire (prior art), but Goodyear could patent a specific tread pattern or novel method of manufacturing tires. A perfectly valid patent, but not as valid as having a broad patent on the wheel.
Excellent point. Discovering infringement of patents that cover integrated circuit internals is EXTREMELY difficult.
Decapping an IC properly and analyzing the internal circuitry is extremely expensive and time consuming. I wouldn't be surprised if they had spent 2-3 years simply determining whether the chips infringed or not. Of course, by that time the chips would be replaced with new models and UW would have to either: a) Prove the new chips were designed similarly to the old ones b) Seek only damages for past products sold and not licensing/royalties for future products
Netgear RangeMax WPN511 (NOT WPNT511 RangeMax 240, NOT any "RangeMax Next" products)
Actually, a better answer: Anything that advertises 108 Mbps "Super G". "Super G" is an Atheros trademark, and only WLAN cards with Atheros chipsets are allowed to carry that mark.
Also, anything Intel PRO/Wireless based works well under Linux. I keep on seeing people (actually, basically only Theo de Raadt...) bitch about Intel and wireless, but the fact is that all of their chipsets are very well supported, and Intel has provided much of the support to developers needed in order to write drivers. Unfortunately Intel PRO/Wireless chipsets are usually only available if it was bought with the system. Even Intel's newest IPW chipset (the 3945ABG) works well under Linux, my new laptop has one.
No tunnel vision (hell, compared to glasses my peripheral vision is incredible!:) , I had haloing at night for about a year but it's gone now.
There's a slight possibility I might eventually need a tuneup, although after 5 years I can still fully function without any additional correction, most likely if I ever need more "oomph" I'll get glasses with a very low correction for that tweaking when I want REALLY sharp vision.
FYI, in my case my vision was HORRIBLE prior to LASIK - +6.25 diopters in one eye and +6.75 in the other I believe, combined with awful astigmatism which prevented contacts from ever working well for me and made even glasses with high-index lenses extremely thick. In the 5 years since I had the procedure performed, equipment and techniques have improved even more.
I'm not sure how anyone you know didn't see vast improvement with LASIK unless: a) The doctor screwed up. Sadly, there are a lot of shlocky doctors who shouldn't ever be allowed near anyone's eyes doing the procedures. I had mine done by a reputable doctor that was recommended by another opthamologist who was a friend of the family. It cost far more (over twice as much per eye) than the "el cheapo" shlocky advertises-on-TV-and-radio doctors, but you get what you pay for. b) They had such low correction needs they probably didn't really need LASIK anyway. The good LASIK doctors refuse to treat such patients. (Ones with too little need for correction to justify the risk or with "difficult" correction needs, such as astigmatism + farsightedness or a cornea that is too thin to begin with.)
I find it amusing that at least one of their "predictions" came true in even better form years ago.
"Implantable contact lenses" - why implant something when you can just fix the cornea itself? I had LASIK performed five years ago, and it wasn't even that new then. It has improved even more in the past five years too. Corneal implants for those with cataracts have existed for even longer.
"the second is, is it that much cheaper to use a simulator than small craft? i'm not sure what the slowdown is there. unless maybe a single instructor can watch over more than one student at a time in simulators. if the pros think this training is important, i would give that a lot of weight."
The good simulators cost far more than a small craft, to the point where I believe many airlines rent sim time from larger airlines because they can't afford to buy their own sims.
The sims are more expensive, but the theory here is most likely a combination of: 1) High-end sims are more representative of a large aircraft than a small aircraft. 2) High-end sims are far safer
"Well, it used to be the case that Ipod had some *real* technical and usability advantages over their competitors, not just "style" (which is a stupid reason to buy something, IMO). Competition is clearly catching up, and if Apple doesn't makes big innovative updates to the ipod, others will have the chance to do and steal market share from Apple." Even once the competition catches up in usability (they already may have?), Apple has a good reputation of usability. So many people have been burned by buying consumer electronics that they will often go with the "safe bet" from a vendor with a proven track record.
That's why I bought an iPod - Even if the competition has caught up, the iPod has the best track record in terms of UI design, and simply put, when you buy an iPod you know what you're getting. With the competition, often you don't. (This is made even worse by the fact that some of the most attractive alternatives were not available in any brick & mortar store anywhere nearby, anything I couldn't at least play with for a few minutes before buying was out of the question.)
S3 Texture Compression (S3TC) - The initial cause of ATI going closed-source with their drivers after a long track record of being (nearly) fully open source.
I'm sure there are plenty of other examples, but S3TC (the reason Unreal Tournament 2003 only ran with NVidia cards with the NV binary drivers until ATI released their first binary drivers) is the first well-known example.
Implementing S3TC goes WAY beyond documenting a few registers. Modern video drivers do far more than you realize, they aren't just some low-level glue.
Speaking of low-level glue, most if not all of the NVidia kernel module is in this category and source is available, but it's useless without the (non-kernel) userspace X11 driver.
"You aren't switching your graphics card and buying a linux-compatible one (something you can fix with money)."
Please, show me how you can fix this with money.
All the money in the world won't help if that which you are looking for isn't sold.
OK, I admit, enough money and you can pay for development of a new chipset that has open drivers and acceptable performance (no, the Intel GMA-series does NOT count as acceptable performance for many users, and the original poster is using a GeForce 6800, which says he is in this class of users like myself.), but that's not within the reach of any Slashdot reader I know of.
I think switching to Windows is extreme. Even if the patch referred to by this story made it into the stock tree, the patch would be patched within days.
I think if the Linux kernel ever has a substantial fork (as opposed to a seperate branch that tracks the main tree such as the RedHat and Gentoo kernels), it'll probably be over this issue.
Diamonds are hard in terms of "they don't scratch" but are (relatively) brittle. I believe if you smash a diamond with a hammer it WILL shatter along its crystal faces. (I could be wrong on this)
For eyeglasses, while scratchproofing is nice, impact resistance is far more important. I don't want diamond lenses that will shatter into a bunch of tiny sharp pieces when a hockey player with no aim sends a puck into the opposing team's pepband and not the goal. (Yes, Harvard hockey players are THAT bad.) Polycarbonate shatterproof lenses (yes, that's right, PLASTIC is one of the toughest lens materials available in terms of impact resistance) saved my eyesight that day. I took a puck right to the lens, the lens distributed the impact around my eyes, resulting in a lot of stitches but no blindness. Oh, and after getting stitched up I bent the frame back into shape and popped the lens right back in.
FYI, Verizon sets their phone's programming mode password to 000000 on nearly every phone I've ever used. In the old days, CS reps would even give you this password when activating a phone that was mailed to you (before the age of automatic OTA programming) or when changing your phone's number assignment (again, before automatic OTA programming).
Thus, nothing is ever needed to unlock a Verizon phone, for all practical purposes. Yes, they have a password, there's no way for the phone NOT to have one without massive customization, but unlike a certain other CDMA provider ("The clear alternative to ourselves!"), they set the password to the same default on every phone they cell.
Not like it'll help you, as that "Clear Alternative" (basically the only CDMA competition unless you live in one of the relatively small Alltel areas) keeps a whitelist of the ESNs of every phone that they have ever sold, and will refuse to activate any phone not on that whitelist, unlocked or not.
Verizon, on the other hand, happily would activate ex-"Clear Alternative" phones if you actually managed to unlock the thing and change its password to 000000 (the method people used for about a year to activate Treo 650s on VZW before it finally got through Verizon QA testing.) I hear this has changed though.
The difference has to do with how multiplexing of multiple calls on a single channel is done.
GSM uses a TDMA scheme, where each user is allocated a timeslot and transmits only in that timeslot. This "bursty" nature of the transmissions is why you often hear interference at the same frequency as the GSM frame repetition rate. (I forget the exact rate.)
CDMA is a different scheme. It operates by assigning each user an orthogonal or semi-orthogonal code. (If I recall correctly, CDMA codes are not quite orthogonal, but are very close). As a result, instead of transmitting short bursts in their assigned timeslot, all users transmit continuously at the same time in a manner that allows the base station to seperate out their transmissions.
Note that there are multiple CDMA-based implementations: cdmaOne aka IS-95 (2G) , CDMA2000 (2.5G/3G depending on which specific CDMA2000 variant), and UMTS, which is 3G GSM
Something doesn't sound right there, as last time I checked, Verizon had a cross-roaming agreement with Sprint that let Verizon users use Sprint towers.
Sprint users can also use Verizon towers, but it requires (or at least required) an extra fee of around $5/month and had a limitation of the percentage of non-Sprint usage.
Perhaps your PRL on the Verizon phone was outdated. *228 option 2 is your friend. (Which reminds me, I haven't done a PRL update in a few months.)
This is one of the reasons why minute-per-minute, Verizon is more expensive than other carriers. You get what you pay for.
I am an incredibly happy Verizon customer, at least for voice service. I think Verizon's data pricing is awful though - Unlike voice service, Verizon's data services are NOT a case of "you get what you pay for". As a result, despite having a Treo 650, I'm still on a voice-only plan.
Re:Why was 192 picked as private?
on
Map of the Internet
·
· Score: 2, Informative
192 = 128*1.5 or 128 + 64
i.e. while not strictly a power of two, it is closely related to one.
More specifically, the bit pattern for 192 is a nice clean 11000000
It looks like they are relying on using two photons of half the required excitation energy (twice the wavelength) rather than one photon of the exact excitation energy. The probability of two photons arriving close enough in time is far less than the probability of one, and as a result it appears the excitation response is a very nonlinear function of light intensity.
See http://belfield.cos.ucf.edu/one%20vs%20two-photon% 20excitation.html - It appears that the big difference in this "two photon" excitation method is that excitation only occurs at the very focal point of the beam where the intensity is at a maximum, as opposed to basically any point in the beam.
Well, I did mention that in my post - "BTW, yes, it IS true that at higher carrier frequencies, there is more free spectrum available to use wider channels, but there is no direct link between carrier frequency and channel capacity as you claim."
In addition to there being more free spectrum, it's also true that many aspects of transmitter and receiver construction become more difficult as the ratio of bandwidth to carrier frequency increases. i.e. an antenna covering 1 GHz of bandwidth with a 2 GHz carrier frequency would be rather difficult (without the antenna being severely nonoptimal for its size at any part of the covered frequency range), while 1 GHz bandwidth with a 50 GHz carrier is much easier.
As others have said, 2.4 bits/sec/Hz isn't particularly amazing, although that number implies over 2 GHz of actual channel bandwidth for a 6 gigabit/sec channel, which IS rather impressive, if only for the fact that a receiver for that signal would have to do baseband processing of at least 4-5 gigasamples/sec of data (2x the channel bandwidth at a minimum), and a 4-5 gigasample/sec ADC is no small feat, neither is the processing power needed to deal with the output of that ADC. It's not something that we will see any time soon in the real world though - any part of the RF spectrum below 10-20 GHz is too crowded to have routine usage of a communications system with 2 GHz of raw channel bandwidth, and above those frequencies you start running into severe line of sight restrictions and high path losses due to water absorption in the air. Not too big of a problem for point-to-point links with fixed high-gain antennas, but a big problem for mobile devices, and mobile devices are the future of wireless. (In my opinion, freespace optical and/or plain old optical fiber buried in the ground are far better options for fixed point-to-point links.)
Slashdot Mirror
Don't think yours would be worth much, it's kinda high.
"Someone please explain how a virus can update a Skype user's telephone book? Seems like a poorly-designed software that allows voice telephone messages to modify its database."
Easy. The skype user's telephone book is most likely (I don't use Skype so I can't be sure) a file on their PC.
A virus can enter that PC in any of the normal ways that they can propagate and go modify that file. (i.e. it isn't a "VoIP Virus", it's a traditional virus that attacks your address book once you're infected)
While my bank has quite a few online services, it appears that many require a phone call or in-person visit.
:)
Of course, since my bank has a branch office right next to my company's cafeteria, I don't consider this an issue.
I don't store numbers in any address book that are on websites I frequently use, this includes all of my banks. (100% of phone calls to the bank are usually the result of a "you can't do this online, call 1-800-xyz-abcd".
The limit is probably on how many times the unburned file can be viewed on a PC.
Which is really nonsensical since the first thing most people are likely to do is burn it to an "unlimited" DVD-R.
Good point.
Still, an expensive and time-consuming process to start.
Um, you really have your estimates of difficulty way off.
With the exception of the electronics (which are extremely simple, USB HID devices can be implemented in a $5-8 Atmel AVR chip which is still available in DIP packaging on a single-layer single-side circuit board), nothing needed to make a high-quality dance pad (at least in terms of tools, some of the specialty materials might need to be sourced elsewhere) can't be bought at your local Lowes or Home Depot.
On the other hand, equipment to produce a multilayer PCB or solder BGA ICs (which basically require using solder reflow techniques) is far harder and more expensive to obtain.
Yes, you can do reflow soldering with a skillet or toaster oven, but it's not the sort of thing I'd ever consider for anything but "personal use" one-off projects. Multilayer PCBs - to my knowledge there is no way to DIY them.
Yes, the DDR dance pads may be labor intensive, but they are not capital-intensive. Thus the price of the dance pads doesn't change much with volume, where as the cost of a custom motherboard for a modern computer would be thousands of dollars per unit in small quantities due to the initial capital expenditure needed.
Simple. They have not patented Bluetooth or anything related to the protocol itself, but have patented a specific way of designing an RF receiver.
That specific way is not specified in the Bluetooth protocol.
Also, this patent isn't limited in any way to Bluetooth only. It can be applied to any RF receiver that is designed in a similar way for any protocol.
Likewise, a Bluetooth chipset manufacturer can choose a receiver architecture that doesn't infringe on this patent. It just may suffer from reduced performance or increased cost. I haven't had time to read the details of the patent, but from what I've seen and other have said, the patent is on a method of implementing an RF receiver in silicon that reduces the number of external analog components needed (and hence the cost) without a significant negative impact on performance.
Whoever submitted the article was an idiot. There is nothing Bluetooth-specific about these patents, and you can't sell a patent under a brand name.
You can sell (or give) ownership of a patent to another entity
You can license the right to use the patent to another entity
I would need to read the patent more to comment on it, but while the individual techniques are all well-known, the architecture of the whole receiver seems to be what this covers.
To me it looks like a very narrow patent, it would be extremely difficult to prove that an IC used this particular architecture, and would be reasonably easy to work around I think.
Sort of like how no one can patent a wheel (prior art) or a tire (prior art), but Goodyear could patent a specific tread pattern or novel method of manufacturing tires. A perfectly valid patent, but not as valid as having a broad patent on the wheel.
Excellent point. Discovering infringement of patents that cover integrated circuit internals is EXTREMELY difficult.
Decapping an IC properly and analyzing the internal circuitry is extremely expensive and time consuming. I wouldn't be surprised if they had spent 2-3 years simply determining whether the chips infringed or not. Of course, by that time the chips would be replaced with new models and UW would have to either:
a) Prove the new chips were designed similarly to the old ones
b) Seek only damages for past products sold and not licensing/royalties for future products
Netgear RangeMax WPN511 (NOT WPNT511 RangeMax 240, NOT any "RangeMax Next" products)
Actually, a better answer: Anything that advertises 108 Mbps "Super G". "Super G" is an Atheros trademark, and only WLAN cards with Atheros chipsets are allowed to carry that mark.
Also, anything Intel PRO/Wireless based works well under Linux. I keep on seeing people (actually, basically only Theo de Raadt...) bitch about Intel and wireless, but the fact is that all of their chipsets are very well supported, and Intel has provided much of the support to developers needed in order to write drivers. Unfortunately Intel PRO/Wireless chipsets are usually only available if it was bought with the system. Even Intel's newest IPW chipset (the 3945ABG) works well under Linux, my new laptop has one.
No tunnel vision (hell, compared to glasses my peripheral vision is incredible! :) , I had haloing at night for about a year but it's gone now.
There's a slight possibility I might eventually need a tuneup, although after 5 years I can still fully function without any additional correction, most likely if I ever need more "oomph" I'll get glasses with a very low correction for that tweaking when I want REALLY sharp vision.
FYI, in my case my vision was HORRIBLE prior to LASIK - +6.25 diopters in one eye and +6.75 in the other I believe, combined with awful astigmatism which prevented contacts from ever working well for me and made even glasses with high-index lenses extremely thick. In the 5 years since I had the procedure performed, equipment and techniques have improved even more.
I'm not sure how anyone you know didn't see vast improvement with LASIK unless:
a) The doctor screwed up. Sadly, there are a lot of shlocky doctors who shouldn't ever be allowed near anyone's eyes doing the procedures. I had mine done by a reputable doctor that was recommended by another opthamologist who was a friend of the family. It cost far more (over twice as much per eye) than the "el cheapo" shlocky advertises-on-TV-and-radio doctors, but you get what you pay for.
b) They had such low correction needs they probably didn't really need LASIK anyway. The good LASIK doctors refuse to treat such patients. (Ones with too little need for correction to justify the risk or with "difficult" correction needs, such as astigmatism + farsightedness or a cornea that is too thin to begin with.)
I find it amusing that at least one of their "predictions" came true in even better form years ago.
"Implantable contact lenses" - why implant something when you can just fix the cornea itself? I had LASIK performed five years ago, and it wasn't even that new then. It has improved even more in the past five years too. Corneal implants for those with cataracts have existed for even longer.
I think he was replying to his parent post, which was something along the line of "what about laptops?"
"the second is, is it that much cheaper to use a simulator than small craft? i'm not sure what the slowdown is there. unless maybe a single instructor can watch over more than one student at a time in simulators. if the pros think this training is important, i would give that a lot of weight."
The good simulators cost far more than a small craft, to the point where I believe many airlines rent sim time from larger airlines because they can't afford to buy their own sims.
The sims are more expensive, but the theory here is most likely a combination of:
1) High-end sims are more representative of a large aircraft than a small aircraft.
2) High-end sims are far safer
"Well, it used to be the case that Ipod had some *real* technical and usability advantages over their competitors, not just "style" (which is a stupid reason to buy something, IMO). Competition is clearly catching up, and if Apple doesn't makes big innovative updates to the ipod, others will have the chance to do and steal market share from Apple."
Even once the competition catches up in usability (they already may have?), Apple has a good reputation of usability. So many people have been burned by buying consumer electronics that they will often go with the "safe bet" from a vendor with a proven track record.
That's why I bought an iPod - Even if the competition has caught up, the iPod has the best track record in terms of UI design, and simply put, when you buy an iPod you know what you're getting. With the competition, often you don't. (This is made even worse by the fact that some of the most attractive alternatives were not available in any brick & mortar store anywhere nearby, anything I couldn't at least play with for a few minutes before buying was out of the question.)
S3 Texture Compression (S3TC) - The initial cause of ATI going closed-source with their drivers after a long track record of being (nearly) fully open source.
I'm sure there are plenty of other examples, but S3TC (the reason Unreal Tournament 2003 only ran with NVidia cards with the NV binary drivers until ATI released their first binary drivers) is the first well-known example.
Implementing S3TC goes WAY beyond documenting a few registers. Modern video drivers do far more than you realize, they aren't just some low-level glue.
Speaking of low-level glue, most if not all of the NVidia kernel module is in this category and source is available, but it's useless without the (non-kernel) userspace X11 driver.
"You aren't switching your graphics card and buying a linux-compatible one (something you can fix with money)."
Please, show me how you can fix this with money.
All the money in the world won't help if that which you are looking for isn't sold.
OK, I admit, enough money and you can pay for development of a new chipset that has open drivers and acceptable performance (no, the Intel GMA-series does NOT count as acceptable performance for many users, and the original poster is using a GeForce 6800, which says he is in this class of users like myself.), but that's not within the reach of any Slashdot reader I know of.
I think switching to Windows is extreme. Even if the patch referred to by this story made it into the stock tree, the patch would be patched within days.
I think if the Linux kernel ever has a substantial fork (as opposed to a seperate branch that tracks the main tree such as the RedHat and Gentoo kernels), it'll probably be over this issue.
Um, that wouldn't help.
Diamonds are hard in terms of "they don't scratch" but are (relatively) brittle. I believe if you smash a diamond with a hammer it WILL shatter along its crystal faces. (I could be wrong on this)
For eyeglasses, while scratchproofing is nice, impact resistance is far more important. I don't want diamond lenses that will shatter into a bunch of tiny sharp pieces when a hockey player with no aim sends a puck into the opposing team's pepband and not the goal. (Yes, Harvard hockey players are THAT bad.) Polycarbonate shatterproof lenses (yes, that's right, PLASTIC is one of the toughest lens materials available in terms of impact resistance) saved my eyesight that day. I took a puck right to the lens, the lens distributed the impact around my eyes, resulting in a lot of stitches but no blindness. Oh, and after getting stitched up I bent the frame back into shape and popped the lens right back in.
FYI, Verizon sets their phone's programming mode password to 000000 on nearly every phone I've ever used. In the old days, CS reps would even give you this password when activating a phone that was mailed to you (before the age of automatic OTA programming) or when changing your phone's number assignment (again, before automatic OTA programming).
Thus, nothing is ever needed to unlock a Verizon phone, for all practical purposes. Yes, they have a password, there's no way for the phone NOT to have one without massive customization, but unlike a certain other CDMA provider ("The clear alternative to ourselves!"), they set the password to the same default on every phone they cell.
Not like it'll help you, as that "Clear Alternative" (basically the only CDMA competition unless you live in one of the relatively small Alltel areas) keeps a whitelist of the ESNs of every phone that they have ever sold, and will refuse to activate any phone not on that whitelist, unlocked or not.
Verizon, on the other hand, happily would activate ex-"Clear Alternative" phones if you actually managed to unlock the thing and change its password to 000000 (the method people used for about a year to activate Treo 650s on VZW before it finally got through Verizon QA testing.) I hear this has changed though.
The difference has to do with how multiplexing of multiple calls on a single channel is done.
GSM uses a TDMA scheme, where each user is allocated a timeslot and transmits only in that timeslot. This "bursty" nature of the transmissions is why you often hear interference at the same frequency as the GSM frame repetition rate. (I forget the exact rate.)
CDMA is a different scheme. It operates by assigning each user an orthogonal or semi-orthogonal code. (If I recall correctly, CDMA codes are not quite orthogonal, but are very close). As a result, instead of transmitting short bursts in their assigned timeslot, all users transmit continuously at the same time in a manner that allows the base station to seperate out their transmissions.
Note that there are multiple CDMA-based implementations: cdmaOne aka IS-95 (2G) , CDMA2000 (2.5G/3G depending on which specific CDMA2000 variant), and UMTS, which is 3G GSM
Something doesn't sound right there, as last time I checked, Verizon had a cross-roaming agreement with Sprint that let Verizon users use Sprint towers.
Sprint users can also use Verizon towers, but it requires (or at least required) an extra fee of around $5/month and had a limitation of the percentage of non-Sprint usage.
Perhaps your PRL on the Verizon phone was outdated. *228 option 2 is your friend. (Which reminds me, I haven't done a PRL update in a few months.)
This is one of the reasons why minute-per-minute, Verizon is more expensive than other carriers. You get what you pay for.
I am an incredibly happy Verizon customer, at least for voice service. I think Verizon's data pricing is awful though - Unlike voice service, Verizon's data services are NOT a case of "you get what you pay for". As a result, despite having a Treo 650, I'm still on a voice-only plan.
192 = 128*1.5 or 128 + 64
i.e. while not strictly a power of two, it is closely related to one.
More specifically, the bit pattern for 192 is a nice clean 11000000
That's designed for small form factor servers.
2.5 inch form factor does not automatically mean "laptop drive".
Please show me a laptop that uses SAS instead of SATA or PATA.
One of the other links gives better detail.
% 20excitation.html - It appears that the big difference in this "two photon" excitation method is that excitation only occurs at the very focal point of the beam where the intensity is at a maximum, as opposed to basically any point in the beam.
It looks like they are relying on using two photons of half the required excitation energy (twice the wavelength) rather than one photon of the exact excitation energy. The probability of two photons arriving close enough in time is far less than the probability of one, and as a result it appears the excitation response is a very nonlinear function of light intensity.
See http://belfield.cos.ucf.edu/one%20vs%20two-photon
Well, I did mention that in my post - "BTW, yes, it IS true that at higher carrier frequencies, there is more free spectrum available to use wider channels, but there is no direct link between carrier frequency and channel capacity as you claim."
In addition to there being more free spectrum, it's also true that many aspects of transmitter and receiver construction become more difficult as the ratio of bandwidth to carrier frequency increases. i.e. an antenna covering 1 GHz of bandwidth with a 2 GHz carrier frequency would be rather difficult (without the antenna being severely nonoptimal for its size at any part of the covered frequency range), while 1 GHz bandwidth with a 50 GHz carrier is much easier.
As others have said, 2.4 bits/sec/Hz isn't particularly amazing, although that number implies over 2 GHz of actual channel bandwidth for a 6 gigabit/sec channel, which IS rather impressive, if only for the fact that a receiver for that signal would have to do baseband processing of at least 4-5 gigasamples/sec of data (2x the channel bandwidth at a minimum), and a 4-5 gigasample/sec ADC is no small feat, neither is the processing power needed to deal with the output of that ADC. It's not something that we will see any time soon in the real world though - any part of the RF spectrum below 10-20 GHz is too crowded to have routine usage of a communications system with 2 GHz of raw channel bandwidth, and above those frequencies you start running into severe line of sight restrictions and high path losses due to water absorption in the air. Not too big of a problem for point-to-point links with fixed high-gain antennas, but a big problem for mobile devices, and mobile devices are the future of wireless. (In my opinion, freespace optical and/or plain old optical fiber buried in the ground are far better options for fixed point-to-point links.)