Peak US energy consumption will be about 250 GW. So worst case 12h of storage is 3 TWh. Over 12h the consumption won't always be at the peak, so a good guess at what 12h US energy storage really means is about 1TWh of storage capacity and this storage must be capable of delivering 250GW peak !! Wow that I big dam with hundreds of massive turbo-generators attached.. Assuming that we need to call on that 12h of storage several times per year, say 5, that about 5TWh/yr of hydro-electric capacity
About the only storage mecanism actual capable of delivery that type of storage is hydro-electric, the question is now is that realistic. At the moment the US has 282 TWh/yr and a peak of 80 GW. About half of that 282 TW/h is probably run of the river type and so must be used immedately or risk severe local flooding. But even still 140 TWh/yr of other hydro-electric capacity is well and truly in the ball park of the author estimations, though might need bigger dams to store the water and deliver power over 12 hours rather than over shorter periods.
One remaining problem is the peak production capacity which would need to be tripled. The logistics of doing that without creating waves you could surf on in US rivers will be amusing but probably not insurmountable. In any case there would need to be a massive investment program in hydro-electric power as well.
The last problem is that last 10% of production that the authors haven't addressed. If its not wind, solar or hydro, what is it ? With current technology, about the only thing that would make sense is combined-cycle gas turbines, allowing for high efficiency and rapid deployment when the wind ain't blowing, the sun ain't shining and after you've used your 12h of energy storage. So the authors are asking the energy industry to build 250GW of production capacity that is only used 10% of the time. That's ok, but it means the infrastructure costs need to be amortized over few production hours, and the price of a MW/h from the combined-cycle generation will cost many times the current cost.
In short, yes the authors proposal seems highly possible on paper, though the US citizens must decide that they are willing to pay much more for power that they are now, and/or go without 10% of the time. Seems to me its a politico-economic choice in that case rather than a technological one. Unfortunately, recent history in the US with the massive exploitation of shale oil and reduction in cost per MW/h of power in the US is the reverse of the decision the authors are advocating, and I'm not sure that US political system has the balls to stand up tell everyone they have to pay more.
Again this is not about the peak power source but the replacement of a base power source by an intermittent one. The 10 hour number is a number that wouls allow the lack of an intermittent source to be replaced by battery for a reasonable period of time.
So storage is even further away from being needed?
As the title of the article is "Solar Could Lead In Power Production By 2050" and the only way Solar can do that is to replace a base power source then storage is needed to make an intermittent source like Solar look like a base source from the grids persepective then yes storage is needed.
Understand I work for a power company, and as I said I'm giving the electric companies perspective.
And energy use goes down on cloudy days (less A/C used). You are looking for a problem that doesn't exist. There are plenty of battery technologies out there. They aren't used because they aren't economical, not because they don't exist.
I'd say you live in a warm climate.. Cloudy days means more energy in colder climates. France uses at its peak about 100 GWatts of electricity. Say you'll need at least 10 hours of battery storage, then you are talking about 1 TWh of power storage for 100% replacement by PV. You can't seriously imagine that any current battery technology can supply that type of storage. Hydro can get you part of the way there, but the largeset damn in France has 800MW of generation and can only supply about 2h at that level. As well that dam is not a STEP (Pump water up hill when power is cheap to store energy) and there are only 5 such dams in France for geographical reasons. So as I said there is not storage technologies that are suitable
I never meant storage technologies don't exist just as you say they are not economically viable or available in large enough quantities to make any meanful difference.
There isn't enough solar production to make storage save anything.
Storage is not about "saving" anything, its about making the supplied energy meet exactly the demand. With an intermittent source such as PV you absolutely need another means to ensure demand meets supply, with the ultimate means availble to the power grid being of course a blackout.
And it's what, about 80% of usage during the day? So until that 40% approaches 80%, they obviously don't have over-production of solar that would allow storage. If they had "perfect" storage now, it wouldn't be used. So that's obviously not the problem..
If fact the 40% peak PV is for a Sunny Sunday afternoon, so a lot further away from 80% than you think..
"Production" needs to be 100% of usage before storage without parallel generation would be feasible. 40% is well below the ability to serve those areas, no matter what the storage was.
Why ? Storage already exists in the grid in reasonable quantities by pumping water up hill. I really think you have no idea how a power grid works.
The supply of electricity must meet the demand at all times, with a little bit of slack taken up in voltage or frequency drops. To meet this simple supply/demand equation, traditionnally there the power production means were split in the two types; "Base" and "Peak". The optimal base energy source is extremely cheap, in Europe on the order of 50€ to 100€ per MWh but with frakking in the US a bit cheaper on the other side of the pond, but difficult to put online, with lead times from hours to days. "Peak" power is optimised for the time it take to put online, of the order of minutes but not cost. A gas turbine might, basically a jet engine with a 200Wh inline generator, costs 1000€ or so for a MWh of prodution. PV and most other renewable energy sources are "Intermittent", so in periods where the base supply is sufficent, they subsitute foe the base supply source, but without storage you can you remove the base source because the source is intermittent. Any amount of storage can allow the removal of some base power source, but to make a meanful reduction in the base source you'd need at least 10h of storage of that base storage. For example to get rid of a 900 MW nuclear reactor at replace it with 900 MW of PV you'd need 9GWh of storage.
From an energy companies perspective the big problem with solar is that you need to think about what happens on a cloudy day or at night. Basically that means you need to have altenative capacity to produce energy that is in most cases 100% of the installed PV capacity, as the power storage technologies that are available now just aren't up to storing the PV from sunny days for later use. For example PV represents upto 40% of the power for the French operator SEI (sei.edf.fr) who supply power to Corsica, Martinique, Guadoloupe, etc. However, they have enormous diesel generators they replace the PV at night and cloudy days.
Until we have better power storage technologies, wind and solar can never represent more than a fraction of the power mix because it is just not economically feasible to have the replacement generation capacity that is sitting around doing nothing when its sunny.
as well as they the human body radiates about 100Watts or 500 times more power than the maximum allowed power from a WiFi access point. Going out it sun is definitely out as at 1kW per square meter of 5000 times strong than WiFi that definitely going to be fatal...
You do of course realize that DSK was the man most likely to be the next president of France up until this accusation? French politics is not really that clean either. Lookup "clearstream sarkozy" and look at how another party infight turned to corrupt means to taint Sarkozy's image before the last election, which backfired and ended up even boasting his popularity, eliminated the other presidential candidates.
The next presidential election in France is in May 2012 and the socialist party is just about to select their candidate. The timing of this scandal is just "too" convenient. If he is guilty most French people I know say "let him hang", but most also have serious doubts given the political context surrounding the case.
Except that from my days working with ADCs and coherent demodulation I know that 1deg of phase error between the two transmit signals will reduce the isolation between the two transmitted signal to 40dB. That 1deg of phase difference is 0.3mm at 2.4GHz
The authors say they need 50dB of isolation, whereas as my guess they need more like 60dB for a reasonable transmit power. There is a need to precisely place three antennas probably about 10cm apart with a positioning error of a very very small fraction of a mm. Difficult to do and mechanically fragile
Not to speak about the fact that the positioning is frequency dependent and so this is going to be an extremely narrowband radioband system.
And have you seen that their first active component in the receive path is an intersil qhx220 that is a noise cancelling LNA. The IIP3 of this LNA is about -21dBm at 2.4GHz, so the P1dB will be about 10dB under that, and OFDM signals typically needing 5dB backoff from the P1Bb to get in the PER specs of 802.11x. So lets assume they are transmitting 15dBm from their transmit antennas (typical for a portable WiFi device) to avoid your LNA going non-linear you want to the cancellation of the transmit signals at the receive antenna to be more like 60dB of cancellation. Even if they get that in the antennas I hope their receive electronics are well shielded because even ignoring the antennas, getting the isolation between the transmit and receive paths better than 60dB is going to be a challenge in a low cost and/or small device. So this thing is going to be gold plated and hand tuned to even get it to partially work
These things have been sold for over 10 years by the French company Satimo for the type of rapid antenna measurements that are needed when you're measuring in the presence of a human. Look at the website
Except supratentorial gilomas being tumors that form outside the membrane of the brain are a type of tumor that is more likely to be in close proximity to the ear (rather than deeper in the brain) where the specific absorption of microwaves will be the highest.. Seems like a good type of brain tumor to base a study of the effects of mobile phones on the brain on.
Yes its standard practice, but no it doesn't produce the best strategy in the context of 802.11. The problem is that the 802.11 MAC clear channel assessment minimizes the opportunity for interference but in fact reduces the opportunity to transmit even in cases that won't interfere. That is I might be trying to communicate with an AP that is 10 metres away, but can see a transmission on the same channel from an AP 100 metres away and the CCA will prevent me from transmitting, even though I probably won't interfere with the other transmission and he certainly won't interfere with me.
The CCA in 802.11ag is defined in two different manners. The first is that if I can synchronize with a preamble in the channel then I consider the channel occupied. This basically means that anything I can hear at the receiver sensitivity (-85dBm for 802.11ag) in my channel I won't transmit. However this doesn't help for the issue of overlapping channels or non 802.11 transmissions in band. So the second definition is a simple RMS power measurement at 20dB above the receiver sensitivity level. That is if I hear something at -65dBm in my band I don't transmit regardless of what type of signal it is. So I'd rather have someone transmitting on the same channel as I am as far away as possible, and adding more, but overlapping channels, giving the frequency planner more opportunities to do that.
Therefore a better frequency plan in the 2.4GHz band that gains a 20dB advantage from the CCA definition is 1, 7, 13, 2, 8, 14, as that minimizes channel overlaps while maximizing the distance. However channel 14 isn't always available and so 1, 6, 12, 2, 7, 13 is a compromise that is reasonable.
Note that the 802.11n "green-fields" preambles have a better definition of the CCA that is basically the same whether or not your on the same channel. However, I don't think anyones really using these new preambles in 802.11n yet.
If you used a frequency divider chain to bring the frequency down to the same as that of a quartz resonator, or if you expressed the noise from the oscillator in terms of a jitter then yes. However, the phase noise of an oscillator goes up by 3dB for each doubling of frequency, and there is a well known relationship between the Q-factor and the phase noise and a doubling of the Q-factor gives you 6dB of improvement in your phase noise. However, without knowing more its not easy to convert from the Q-factor to a phase noise number..
For a system with 802.11a you need about -110dBc/Hz of phase noise at 1MHz offset. OFDM systems like 802.11a are a bit special with respect to the phase noise as the OFDM modulation (in particular the OFDM pilot tones) is designed to correct for the phase noise that is closer to the carrier than an OFDM carrier spacing (ie about 300kHz). Therefore a really interesting application for such an oscillator is inclusion on chip of the high-Q oscillator for WLAN/Cellular radios, where current commercial designs typically have at least the tank of the VCO off chip. Though for that the oscillator needs to be tunable, and I'm not sure these designs are.
I remember seeing this stuff more than 10 years ago. Being Australian the stuff I saw ten years ago was from an Australian University grant from the DSTO (military research organisation), with information that can be found at http://wwwrsphysse.anu.edu.au/~ggb112/
In fact a Typical Fluroscent tube makes a reasonable HF antenna with its frequency dependent on its length. For those that think the glowing plasma makes the antenna detectable in the visible spectrum, its easy to have a material that is opaque in the visible spectrum but transparent in the radio spectrum. A piece of stryofoam is enough to do the job.
There is one big difference of WiMaX over upgrades of the 3GPP cellular offers. They aren't upgrades, its more or less a clean slate, and new supplier of WiMaX services can break the strangle hold that existing cellular operators have over the mobile communications market. This is a chance for the consumer to get a better deal, from these new operators. With SiP over WiMaX I'd tell my existing cellular operator to go screw themselves..
It should be noted that the CSIRO had a spin-off called RADIATA, and that they had access to this patent. RADIATA was later bought by CISCO, so it seems to me at a first look that CISCO is protected from this patent.. So Buy CISCO....
Although you can't get it there yet, check http://opensource.motorola.com/ where it appears the discussion on this is suppossed to take place, at least from Motorola's point of view..
Bzzz, sorry you don't know what you are talking about. UWB systems we are talking about here are typically very sensitive to other sources of interference. The reason is that they are NOT frequency hopping as you assume, but systems with either 25% BW for greater than 500MHz bandwidth (the definition of UWB of the FCC). They transmit in all of this bandwidth at the same time. The result is that the low noise amplifier in the receiver is very wideband and very open to interference. A typical UWB communications systems will fail in the presence of an interferer long before the interefering source has any effect from the UWB system. Upshot, It'll be easier to jam this WiMedia device than most other technologies. If you don't believe me go at look at the 802.15.3a documents (they are public) and consider why the IEEE avoided the 5 to 6GHz band for UWB in the US. (I'll give you a hint, 802.11a has a similar deployment pattern).
The military applications of UWB are in two areas. Firstly the wideband signals give extremely good time of arrival information that can be used in ranging or for radar (think through wall radar for looking for that terrorist you US critters are so worried about), and the second is in chaotic UWB where the emitted UWB signal is a train of UWB psuedo random pulse shapes, that is effectively noise like and unless you are capable of reproducing the same psuedo random pulse shapes impossible to recognize as a communications signal (thick lovely devices to bug that terrorist with). Sorry, the game is very firmly in the court of the existing miltary as you can be sure that the above is not available to just anyone.
Perhaps you should look at 802.11h, where the CSMA techniques are only used for the contention based resource reservation slots and to support legacy older 802.11 systems. Once you have true resource reservation the hidden node problem goes away. So perhaps it isn't so much that 802.11 needs to "fucking die", but rather it needs to get its act together..
Why? Well they aquired the company Radiata a few years back that worked closely with the CSIRO group responsible for this patent. For 400 million dollars in shares (at the cisco share value at the time) they bought a preliminary 802.11a design.I presume part of the deal was full access to this patent...
Perhaps the author needs to see what research is currently going on in the area of optimizing spectrum usage. The google search is probably a good start. With such techniques the question of freeing up the spectrum is moot.
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Peak US energy consumption will be about 250 GW. So worst case 12h of storage is 3 TWh. Over 12h the consumption won't always be at the peak, so a good guess at what 12h US energy storage really means is about 1TWh of storage capacity and this storage must be capable of delivering 250GW peak !! Wow that I big dam with hundreds of massive turbo-generators attached.. Assuming that we need to call on that 12h of storage several times per year, say 5, that about 5TWh/yr of hydro-electric capacity
About the only storage mecanism actual capable of delivery that type of storage is hydro-electric, the question is now is that realistic. At the moment the US has 282 TWh/yr and a peak of 80 GW. About half of that 282 TW/h is probably run of the river type and so must be used immedately or risk severe local flooding. But even still 140 TWh/yr of other hydro-electric capacity is well and truly in the ball park of the author estimations, though might need bigger dams to store the water and deliver power over 12 hours rather than over shorter periods.
One remaining problem is the peak production capacity which would need to be tripled. The logistics of doing that without creating waves you could surf on in US rivers will be amusing but probably not insurmountable. In any case there would need to be a massive investment program in hydro-electric power as well.
The last problem is that last 10% of production that the authors haven't addressed. If its not wind, solar or hydro, what is it ? With current technology, about the only thing that would make sense is combined-cycle gas turbines, allowing for high efficiency and rapid deployment when the wind ain't blowing, the sun ain't shining and after you've used your 12h of energy storage. So the authors are asking the energy industry to build 250GW of production capacity that is only used 10% of the time. That's ok, but it means the infrastructure costs need to be amortized over few production hours, and the price of a MW/h from the combined-cycle generation will cost many times the current cost.
In short, yes the authors proposal seems highly possible on paper, though the US citizens must decide that they are willing to pay much more for power that they are now, and/or go without 10% of the time. Seems to me its a politico-economic choice in that case rather than a technological one. Unfortunately, recent history in the US with the massive exploitation of shale oil and reduction in cost per MW/h of power in the US is the reverse of the decision the authors are advocating, and I'm not sure that US political system has the balls to stand up tell everyone they have to pay more.
D.
And I thought Wikileaks was the preferred source of NSA source code !!
D.
So a peak that lasts 10 hours?
Again this is not about the peak power source but the replacement of a base power source by an intermittent one. The 10 hour number is a number that wouls allow the lack of an intermittent source to be replaced by battery for a reasonable period of time.
So storage is even further away from being needed?
As the title of the article is "Solar Could Lead In Power Production By 2050" and the only way Solar can do that is to replace a base power source then storage is needed to make an intermittent source like Solar look like a base source from the grids persepective then yes storage is needed.
D.
Understand I work for a power company, and as I said I'm giving the electric companies perspective.
And energy use goes down on cloudy days (less A/C used). You are looking for a problem that doesn't exist. There are plenty of battery technologies out there. They aren't used because they aren't economical, not because they don't exist.
I'd say you live in a warm climate.. Cloudy days means more energy in colder climates. France uses at its peak about 100 GWatts of electricity. Say you'll need at least 10 hours of battery storage, then you are talking about 1 TWh of power storage for 100% replacement by PV. You can't seriously imagine that any current battery technology can supply that type of storage. Hydro can get you part of the way there, but the largeset damn in France has 800MW of generation and can only supply about 2h at that level. As well that dam is not a STEP (Pump water up hill when power is cheap to store energy) and there are only 5 such dams in France for geographical reasons. So as I said there is not storage technologies that are suitable
I never meant storage technologies don't exist just as you say they are not economically viable or available in large enough quantities to make any meanful difference.
There isn't enough solar production to make storage save anything.
Storage is not about "saving" anything, its about making the supplied energy meet exactly the demand. With an intermittent source such as PV you absolutely need another means to ensure demand meets supply, with the ultimate means availble to the power grid being of course a blackout.
And it's what, about 80% of usage during the day? So until that 40% approaches 80%, they obviously don't have over-production of solar that would allow storage. If they had "perfect" storage now, it wouldn't be used. So that's obviously not the problem..
If fact the 40% peak PV is for a Sunny Sunday afternoon, so a lot further away from 80% than you think. .
"Production" needs to be 100% of usage before storage without parallel generation would be feasible. 40% is well below the ability to serve those areas, no matter what the storage was.
Why ? Storage already exists in the grid in reasonable quantities by pumping water up hill. I really think you have no idea how a power grid works.
The supply of electricity must meet the demand at all times, with a little bit of slack taken up in voltage or frequency drops. To meet this simple supply/demand equation, traditionnally there the power production means were split in the two types; "Base" and "Peak". The optimal base energy source is extremely cheap, in Europe on the order of 50€ to 100€ per MWh but with frakking in the US a bit cheaper on the other side of the pond, but difficult to put online, with lead times from hours to days. "Peak" power is optimised for the time it take to put online, of the order of minutes but not cost. A gas turbine might, basically a jet engine with a 200Wh inline generator, costs 1000€ or so for a MWh of prodution. PV and most other renewable energy sources are "Intermittent", so in periods where the base supply is sufficent, they subsitute foe the base supply source, but without storage you can you remove the base source because the source is intermittent. Any amount of storage can allow the removal of some base power source, but to make a meanful reduction in the base source you'd need at least 10h of storage of that base storage. For example to get rid of a 900 MW nuclear reactor at replace it with 900 MW of PV you'd need 9GWh of storage.
D.
From an energy companies perspective the big problem with solar is that you need to think about what happens on a cloudy day or at night. Basically that means you need to have altenative capacity to produce energy that is in most cases 100% of the installed PV capacity, as the power storage technologies that are available now just aren't up to storing the PV from sunny days for later use. For example PV represents upto 40% of the power for the French operator SEI (sei.edf.fr) who supply power to Corsica, Martinique, Guadoloupe, etc. However, they have enormous diesel generators they replace the PV at night and cloudy days.
Until we have better power storage technologies, wind and solar can never represent more than a fraction of the power mix because it is just not economically feasible to have the replacement generation capacity that is sitting around doing nothing when its sunny.
D.
as well as they the human body radiates about 100Watts or 500 times more power than the maximum allowed power from a WiFi access point. Going out it sun is definitely out as at 1kW per square meter of 5000 times strong than WiFi that definitely going to be fatal...
What a load of Bollocks!
D.
You do of course realize that DSK was the man most likely to be the next president of France up until this accusation? French politics is not really that clean either. Lookup "clearstream sarkozy" and look at how another party infight turned to corrupt means to taint Sarkozy's image before the last election, which backfired and ended up even boasting his popularity, eliminated the other presidential candidates.
The next presidential election in France is in May 2012 and the socialist party is just about to select their candidate. The timing of this scandal is just "too" convenient. If he is guilty most French people I know say "let him hang", but most also have serious doubts given the political context surrounding the case.
D:
PS: Though I live in Paris, I'm not French
Except that from my days working with ADCs and coherent demodulation I know that 1deg of phase error between the two transmit signals will reduce the isolation between the two transmitted signal to 40dB. That 1deg of phase difference is 0.3mm at 2.4GHz
The authors say they need 50dB of isolation, whereas as my guess they need more like 60dB for a reasonable transmit power. There is a need to precisely place three antennas probably about 10cm apart with a positioning error of a very very small fraction of a mm. Difficult to do and mechanically fragile
Not to speak about the fact that the positioning is frequency dependent and so this is going to be an extremely narrowband radioband system.
D.
And have you seen that their first active component in the receive path is an intersil qhx220 that is a noise cancelling LNA. The IIP3 of this LNA is about -21dBm at 2.4GHz, so the P1dB will be about 10dB under that, and OFDM signals typically needing 5dB backoff from the P1Bb to get in the PER specs of 802.11x. So lets assume they are transmitting 15dBm from their transmit antennas (typical for a portable WiFi device) to avoid your LNA going non-linear you want to the cancellation of the transmit signals at the receive antenna to be more like 60dB of cancellation. Even if they get that in the antennas I hope their receive electronics are well shielded because even ignoring the antennas, getting the isolation between the transmit and receive paths better than 60dB is going to be a challenge in a low cost and/or small device. So this thing is going to be gold plated and hand tuned to even get it to partially work
D.
Never reached the market? What about the squarial from BSB in the UK in the 90s (http://en.wikipedia.org/wiki/Squarial)
D.
These things have been sold for over 10 years by the French company Satimo for the type of rapid antenna measurements that are needed when you're measuring in the presence of a human. Look at the website
http://www.satimo.com/content/products/sg-64
This is hardly a sign that Apple is modern, but rather they are following behind the antenna measurement industry,
D.
Except supratentorial gilomas being tumors that form outside the membrane of the brain are a type of tumor that is more likely to be in close proximity to the ear (rather than deeper in the brain) where the specific absorption of microwaves will be the highest.. Seems like a good type of brain tumor to base a study of the effects of mobile phones on the brain on.
D.
Yes its standard practice, but no it doesn't produce the best strategy in the context of 802.11. The problem is that the 802.11 MAC clear channel assessment minimizes the opportunity for interference but in fact reduces the opportunity to transmit even in cases that won't interfere. That is I might be trying to communicate with an AP that is 10 metres away, but can see a transmission on the same channel from an AP 100 metres away and the CCA will prevent me from transmitting, even though I probably won't interfere with the other transmission and he certainly won't interfere with me.
The CCA in 802.11ag is defined in two different manners. The first is that if I can synchronize with a preamble in the channel then I consider the channel occupied. This basically means that anything I can hear at the receiver sensitivity (-85dBm for 802.11ag) in my channel I won't transmit. However this doesn't help for the issue of overlapping channels or non 802.11 transmissions in band. So the second definition is a simple RMS power measurement at 20dB above the receiver sensitivity level. That is if I hear something at -65dBm in my band I don't transmit regardless of what type of signal it is. So I'd rather have someone transmitting on the same channel as I am as far away as possible, and adding more, but overlapping channels, giving the frequency planner more opportunities to do that.
Therefore a better frequency plan in the 2.4GHz band that gains a 20dB advantage from the CCA definition is 1, 7, 13, 2, 8, 14, as that minimizes channel overlaps while maximizing the distance. However channel 14 isn't always available and so 1, 6, 12, 2, 7, 13 is a compromise that is reasonable.
Note that the 802.11n "green-fields" preambles have a better definition of the CCA that is basically the same whether or not your on the same channel. However, I don't think anyones really using these new preambles in 802.11n yet.
D.
Opppss. Yes.. Typed too quick
D.
If you used a frequency divider chain to bring the frequency down to the same as that of a quartz resonator, or if you expressed the noise from the oscillator in terms of a jitter then yes. However, the phase noise of an oscillator goes up by 3dB for each doubling of frequency, and there is a well known relationship between the Q-factor and the phase noise and a doubling of the Q-factor gives you 6dB of improvement in your phase noise. However, without knowing more its not easy to convert from the Q-factor to a phase noise number..
For a system with 802.11a you need about -110dBc/Hz of phase noise at 1MHz offset. OFDM systems like 802.11a are a bit special with respect to the phase noise as the OFDM modulation (in particular the OFDM pilot tones) is designed to correct for the phase noise that is closer to the carrier than an OFDM carrier spacing (ie about 300kHz). Therefore a really interesting application for such an oscillator is inclusion on chip of the high-Q oscillator for WLAN/Cellular radios, where current commercial designs typically have at least the tank of the VCO off chip. Though for that the oscillator needs to be tunable, and I'm not sure these designs are.
D.
I remember seeing this stuff more than 10 years ago. Being Australian the stuff I saw ten years ago was from an Australian University grant from the DSTO (military research organisation), with information that can be found at http://wwwrsphysse.anu.edu.au/~ggb112/
In fact a Typical Fluroscent tube makes a reasonable HF antenna with its frequency dependent on its length. For those that think the glowing plasma makes the antenna detectable in the visible spectrum, its easy to have a material that is opaque in the visible spectrum but transparent in the radio spectrum. A piece of stryofoam is enough to do the job.
D.
There is one big difference of WiMaX over upgrades of the 3GPP cellular offers. They aren't upgrades, its more or less a clean slate, and new supplier of WiMaX services can break the strangle hold that existing cellular operators have over the mobile communications market. This is a chance for the consumer to get a better deal, from these new operators. With SiP over WiMaX I'd tell my existing cellular operator to go screw themselves..
D.
hold on whilst I just run "apt-get install.."
In fact the Motorola EZX phones can already do "apt-get install". See http://www.mkezx.org/
D.
It should be noted that the CSIRO had a spin-off called RADIATA, and that they had access to this patent. RADIATA was later bought by CISCO, so it seems to me at a first look that CISCO is protected from this patent.. So Buy CISCO....
D.
Although you can't get it there yet, check http://opensource.motorola.com/ where it appears the discussion on this is suppossed to take place, at least from Motorola's point of view..
D.
Bzzz, sorry you don't know what you are talking about. UWB systems we are talking about here are typically very sensitive to other sources of interference. The reason is that they are NOT frequency hopping as you assume, but systems with either 25% BW for greater than 500MHz bandwidth (the definition of UWB of the FCC). They transmit in all of this bandwidth at the same time. The result is that the low noise amplifier in the receiver is very wideband and very open to interference. A typical UWB communications systems will fail in the presence of an interferer long before the interefering source has any effect from the UWB system. Upshot, It'll be easier to jam this WiMedia device than most other technologies. If you don't believe me go at look at the 802.15.3a documents (they are public) and consider why the IEEE avoided the 5 to 6GHz band for UWB in the US. (I'll give you a hint, 802.11a has a similar deployment pattern).
The military applications of UWB are in two areas. Firstly the wideband signals give extremely good time of arrival information that can be used in ranging or for radar (think through wall radar for looking for that terrorist you US critters are so worried about), and the second is in chaotic UWB where the emitted UWB signal is a train of UWB psuedo random pulse shapes, that is effectively noise like and unless you are capable of reproducing the same psuedo random pulse shapes impossible to recognize as a communications signal (thick lovely devices to bug that terrorist with). Sorry, the game is very firmly in the court of the existing miltary as you can be sure that the above is not available to just anyone.
Perhaps you should look at 802.11h, where the CSMA techniques are only used for the contention based resource reservation slots and to support legacy older 802.11 systems. Once you have true resource reservation the hidden node problem goes away. So perhaps it isn't so much that 802.11 needs to "fucking die", but rather it needs to get its act together..
D.
Why? Well they aquired the company Radiata a few years back that worked closely with the CSIRO group responsible for this patent. For 400 million dollars in shares (at the cisco share value at the time) they bought a preliminary 802.11a design.I presume part of the deal was full access to this patent...
D.
Before you buy a canon check http://www.linuxprinting.org/ and see if you can use your shiny new printer on your linux machine...
D.
Perhaps the author needs to see what research is currently going on in the area of optimizing spectrum usage. The google search is probably a good start. With such techniques the question of freeing up the spectrum is moot.
D.