Commodore64 love, you said
"When you think of it on a kilobyte level it costs us $1.09 per text message Kilobyte. The markup for costs is 7300%."
I'm partially convinced it comes from ignorance rather than a B5 joke or troll. To suggest that phones are constantly texting the tower completely ignores the fact that there is a lot of overhead to carry those 160 bytes. It's not like you can send 160 bytes for free on a cellular system or a wired system for that matter. Signalling to page the phone and establishing connections and packet headers for those messages are not free. Due to mobility the overhead is much more than a wired system. If you had ever read the various cellular standards, you would realize the complexity involved in texting 160 bytes of data.
In GSM/GPRS/EDGE systems (1G, 2G, 2.5G) text messages are carried as a single voice frame. It takes a large amount of signaling overhead to locate the handset and route information to it. In fact, to send 160 bytes of text takes the same overhead as a call setup and release and endless location updates.
In UMTS/HSPA/HSPAplus systems/LTE (3G, 4G) text messages are carried as packets. It still takes a large amount of signaling overhead to constantly track the handset and route information to it. To send the 160 bytes requires packet headers for each of the layers and many more packets just to set up the data transfer. Consider that TCP layers have to be brought up to exchange two layer three packets that carry the 160 byte payload. The messages that are constantly sent to track the phone. Those are signalling overhead.
It's very difficult to compare a data connection being used to carry a 160 byte text messages with a data connection being used to carry a huge payload such as a huge JPG, MP3, etc. A 160 byte text message is dominated by signalling and setting up of various data layers. Downloading an MP3 song is dominated by the data payload.
The rates are outrageously high for the minuscule data passed due to the large overhead involved. It's like asking UPS or FedEX to ship an air sample across the country for free. Afterall, air is free!
The oil plateau is clearly a fact. This means a fixed amount of oil is being produced in the world (86 Mbpd). The US consumes about 1/4 of that. Refineries are about as efficient as they can get. The overall mpg efficiency of passenger cars is pretty steady at 22.5 mpg. --> overall car mileage probably has plateaued.
Clearly it stands to reason that if we have hit peak oil (the rate of oil production), the refineries are not becomming more efficient and if the efficiency of vehicles is not really significantly increasing, then the miles the vehicles travel have also peaked.
* World oil production - 86 million barrels per day (Mbpd) - This has been pretty flat over the last five years.
* US consumption of world oil - The US consumes around 1/4 of the world's oil. Due to the decline in the economy, US oil consumption has fallen some 9%, down nearly 2 million barrels per day (mbpd) from 20.7 mbpd in mid 2007, to about 18.8 mbpd in October 2009
* American Petroleum Institute reports that 1 barrel of oil produced 19.4 gallons of gasoline per barrel based on average yields for U.S. refineries.
Beekeepers earn much more renting their bees out to pollinate crops than in producing honey, and researchers are concerned that trucking colonies around country to pollinate crops could add to bees' stress and help spread viruses and mites of crops that rely on pollination.
(see http://select.nytimes.com/gst/abstract.html?res=F1 0B1FF8355A0C748EDDAB0894DF404482)
Flaws in Harts, Kuhn, Stever (2006) experiment
(the German study that all the papers are referring to)
http://agbi.uni-landau.de/material_download/IAAS_2 006.pdf
The Harts, Kuhn, Stever (2006) experiment is flawed in several ways. It's not a double-blind, randomized study and the controls are not identical to the test unit. I understand it's a preliminary investigation and not a complete study. But even a good science fair project does some things to remove as much bias as possible from its experiment. I'm sorry this is JUNK SCIENCE.
The researchers know which hives are control and which hives have the DECT cordless base unit in it. And, the bees should not be able to detect whether their hive is control or one with a DECT base in it. The problem with this is that the researchers may inadvertently record data wanting a certain result.
Note that the eight control hives had no DECT base unit in them. The bees may not have liked the smell of the DECT base unit or its additional warmth. Perhaps if the hive is warmer, maybe the bees insctinctively know not to collect as much pollen/honey.
In a well designed experiment, both the control and the active bee hives would have antennas mounted in them. The RF source would have been located in a separate enclosure, far away from the bee hive so that it's heat did not change conditions in the hive and connected to the antenna via low-loss transmission line.
The experiment was not re-run so that the bees used as controls in one experiment were then exposed to RF in a subsequent experiment and vise-versa. The bees that got the DECT base station installed into their hive may have been contaminated in one way or another. The bee hives that contained the DECT base units may have been made sick due to the installation of the base units. Perhaps the test hives were at one end of the row of hives and the controls were at the other end. The test hives could have gotten more or less sun exposure than the control hives. The experiment should have removed that variable completely by randomizing which hives were test and which were controls.
The hives could also have been run as self-controls. I.e. the behavior of the hive should have been recorded before and after the experiment with a control period. This would have ensured that the RF was the only variable applied.
The article does not explain the technical flaws they encountered in detail nor do they adequately explain the gaps in the weather data.
They claimed they were looking for "Non-thermal effects of RF" nut did not adequately record temperatures inside of the control and the test hives. They needed to adequately prove that their experiment was not heating the test hive. I also did not see the data on how much the bees had actually eaten when they were fed. They should have taken a much closer look at metabolic changes such as the level of activity in the hive.
The article was not peer reviewed to uncover the above flaws in the experiment. ==> Junk Science
Microwave ovens have are about 30% efficient and output at 2.45Ghz. Their output could be matched to a feedhorn. The problem is that they are difficult to modulate. You can use them to send chirpy CW and maybe AM. But they will not work to send a complex waveform like 64QAM which requires linear characteristics.
Konrad WA4OSH
Having the wrong polarity only induces a 6dB loss. This may be significant to reject a minimallt interfering signal, but it's not enough to block a jammer.
I don't usually reply to my own posts. However, take a close look at Intersil's response. It's
poor engineering on the DARS providers part:
http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?na tive_or_pdf=pdf&id_document=6513081279
Sirius's whole story is starting to sound like Global Crossing. Their previous CEO David Margolese bailed from the project last year and probably collected a small fortune to keep his mouth shut.
iamroot,
It's 67.5 Mhz and obviously crappy receivers. The engineers just did not think too much about putting good front ends on their radios. Or... they are about to go bankrupt. They can't blame it on themselves for being 9 months late with their product.
Of the two DARS bands, Sirius has the LOWER frequency band at 2320.0 to 2332.5 Ghz (at least 67.5 Mhz away where signals are way down in the noise according to my spectrum analyzer) and XM has the higher frequency licences at 2.3325 to 2.3450 Ghz which are much closer to the 2.4 Ghz band (only 50 Mhz away).
The three Sirius satellites on an elliptical orbit are expected to transmit at 15KW signals. One of the three satellites is expected to cover the US at one time.
However, this is not just a satellite service, but it's a ground-based system as well. They are building ground stations to prevent buildings and other obstructions from blocking signals in local areas. In many cities, Sirius and XM expect to cover the entire town with one omni-directional cylindrical antenna approximately 57" tall and 5" in diameter. Perhaps they tried to depend on too few ground repeaters in highly populated areas.
Each service XM and Sirius have 100 channels a piece. It's interesting to note that XM which is directly adjacent to Sirius in its frequency allocations, and also having ground based transmissions is not expected to interfere with Sirius - right. XM will be transmitting at a much higher power lever (~10-100 watts ERP) from the ground-based locations. So why does XM not interfere???
Also, hams are licensed for much more power than part 15 on 2300-2310 and 2390-2450 and are much closer to Sirius's and XM's service than the ISM band. So quite possibly, hams could interfere with their systems as well - we are allowed much more power on these bands than what is allowed on the ISM band by part 15 users (4 watts ERP). My guess is that it won't be due to out of band operations, but probably due to Sirius's poor front-end design.
BTW The 2.4 Ghz band has been and will be full of ISM stuff like 802.11, 802.11b, 802.11g (soon), HomeRF, Bluetooth, 2.4 Cordless phones, microwave ovens, security cameras, SCADA systems, door openers and dozens of other gadgets that have been there for years already.
BTW cell phones use 800Mhz and PCS phones use 1.9Ghz. And should not interfere with their system.
If their system is so great, why did their CEO David Margolese bail??
Konrad Roeder, WA4OSH
Consulting Systems Engineer
http://www.springswireless.com
See http://www.fcc.gov/oet/spectrum/table/fcctable.pdf
I find their claim that the agregate sum of all part 15 use in the 2.4Ghz band is causing them interference a bit hard to understand. It's not like the cars are transmitting up to the satellite and the satellite needs to hear them. Their receivers have a problem rejecting adjacent channel interference. When you want to tune a signal from the satellite at -115dBM with an omnidirectional antenna, they get noise from everything in the area and have a bit of trouble rejecting signals that are in the -30 dBM region inside the same car (or most likely truck), or signals eminating from nearby buildings at -60 dBm?
Here is some more background to consider...
Sirius has the lower frequency band at 2320.0 to 2332.5 Ghz (at least 67.5 Mhz away where signals are way down in the noise according to my spectrum analyzer) and XM has the higher frequency licences at 2.3325 to 2.3450 Ghz which are much closer to the 2.4 Ghz band (only 50 Mhz away). Why is XM not complaining???
Ahhh they paid millions for their licenses and perhaps their receivers are wide as a barnyard door...and their protocol is suceptible to interference? (more than XM?) Perhaps they were so late in the market with XM radio already selling and they can't afford to redesign their radios. And the radios with a better front-end would put their product at a disadvantage with XM?
I think Sirius is serious financial do-do. Sirius Radio service will be available nationwide by the third-quarter of 2002. (9 months later than XM) Until then, it's a ground-based operation. Furthermore, they have had trouble getting Ford and Chrisler on board. Both will offer the radios in '03. (XM has GM as a partner and is selling now) Sirius Radio reported a net loss of $57 million for third quarter '01. Losses are Sirius Radio has also publicly announced that they have enough cash to last until the fourth-quarter of 2002. Their insiders are selling their shares.
I get it -- call in the lawyers and eliminate all part 15. Yeah that's the ticket.
Konrad Roeder
Consulting Systems Engineer
http://www.springswireless.com
Slashdot Mirror
7 digit number? BS Telephone numbers should be type E.164, not integer You send a text message to +15105551234 it should go to Fred.
That customer support is overhead provided by the carrier. When something goes wrong, who are you going to call?
Commodore64 love, you said "When you think of it on a kilobyte level it costs us $1.09 per text message Kilobyte. The markup for costs is 7300%." I'm partially convinced it comes from ignorance rather than a B5 joke or troll. To suggest that phones are constantly texting the tower completely ignores the fact that there is a lot of overhead to carry those 160 bytes. It's not like you can send 160 bytes for free on a cellular system or a wired system for that matter. Signalling to page the phone and establishing connections and packet headers for those messages are not free. Due to mobility the overhead is much more than a wired system. If you had ever read the various cellular standards, you would realize the complexity involved in texting 160 bytes of data. In GSM/GPRS/EDGE systems (1G, 2G, 2.5G) text messages are carried as a single voice frame. It takes a large amount of signaling overhead to locate the handset and route information to it. In fact, to send 160 bytes of text takes the same overhead as a call setup and release and endless location updates. In UMTS/HSPA/HSPAplus systems/LTE (3G, 4G) text messages are carried as packets. It still takes a large amount of signaling overhead to constantly track the handset and route information to it. To send the 160 bytes requires packet headers for each of the layers and many more packets just to set up the data transfer. Consider that TCP layers have to be brought up to exchange two layer three packets that carry the 160 byte payload. The messages that are constantly sent to track the phone. Those are signalling overhead. It's very difficult to compare a data connection being used to carry a 160 byte text messages with a data connection being used to carry a huge payload such as a huge JPG, MP3, etc. A 160 byte text message is dominated by signalling and setting up of various data layers. Downloading an MP3 song is dominated by the data payload. The rates are outrageously high for the minuscule data passed due to the large overhead involved. It's like asking UPS or FedEX to ship an air sample across the country for free. Afterall, air is free!
The oil plateau is clearly a fact. This means a fixed amount of oil is being produced in the world (86 Mbpd). The US consumes about 1/4 of that. Refineries are about as efficient as they can get. The overall mpg efficiency of passenger cars is pretty steady at 22.5 mpg. --> overall car mileage probably has plateaued.
I don't think the roads are a limiting factor. I think it's how much gasoline people are willing to consume each month.
Clearly it stands to reason that if we have hit peak oil (the rate of oil production), the refineries are not becomming more efficient and if the efficiency of vehicles is not really significantly increasing, then the miles the vehicles travel have also peaked. * World oil production - 86 million barrels per day (Mbpd) - This has been pretty flat over the last five years. * US consumption of world oil - The US consumes around 1/4 of the world's oil. Due to the decline in the economy, US oil consumption has fallen some 9%, down nearly 2 million barrels per day (mbpd) from 20.7 mbpd in mid 2007, to about 18.8 mbpd in October 2009 * American Petroleum Institute reports that 1 barrel of oil produced 19.4 gallons of gasoline per barrel based on average yields for U.S. refineries.
Do you believe that the last mile bandwidth to the Internet has anything to do with the demand for storage capacity? I believe it has also stalled.
Beekeepers earn much more renting their bees out to pollinate crops than in producing honey, and researchers are concerned that trucking colonies around country to pollinate crops could add to bees' stress and help spread viruses and mites of crops that rely on pollination. (see http://select.nytimes.com/gst/abstract.html?res=F1 0B1FF8355A0C748EDDAB0894DF404482)
CCD has been happening since the mid 1970's (see http://en.wikipedia.org/wiki/Colony_Collapse_Disor der) Cell phones did not even exist until the mid 80's.
The problem is that the German study did not even involve cell phones. It used Digital Enhanced Cordless Telecommunications (DECT) cordless phones.
(see http://agbi.uni-landau.de/material_download/IAAS_2 006.pdf)
(also see http://en.wikipedia.org/wiki/DECT)
Flaws in Harts, Kuhn, Stever (2006) experiment (the German study that all the papers are referring to) http://agbi.uni-landau.de/material_download/IAAS_2 006.pdf
The Harts, Kuhn, Stever (2006) experiment is flawed in several ways. It's not a double-blind, randomized study and the controls are not identical to the test unit. I understand it's a preliminary investigation and not a complete study. But even a good science fair project does some things to remove as much bias as possible from its experiment. I'm sorry this is JUNK SCIENCE.
The researchers know which hives are control and which hives have the DECT cordless base unit in it. And, the bees should not be able to detect whether their hive is control or one with a DECT base in it. The problem with this is that the researchers may inadvertently record data wanting a certain result.
Note that the eight control hives had no DECT base unit in them. The bees may not have liked the smell of the DECT base unit or its additional warmth. Perhaps if the hive is warmer, maybe the bees insctinctively know not to collect as much pollen/honey.
In a well designed experiment, both the control and the active bee hives would have antennas mounted in them. The RF source would have been located in a separate enclosure, far away from the bee hive so that it's heat did not change conditions in the hive and connected to the antenna via low-loss transmission line.
The experiment was not re-run so that the bees used as controls in one experiment were then exposed to RF in a subsequent experiment and vise-versa. The bees that got the DECT base station installed into their hive may have been contaminated in one way or another. The bee hives that contained the DECT base units may have been made sick due to the installation of the base units. Perhaps the test hives were at one end of the row of hives and the controls were at the other end. The test hives could have gotten more or less sun exposure than the control hives. The experiment should have removed that variable completely by randomizing which hives were test and which were controls.
The hives could also have been run as self-controls. I.e. the behavior of the hive should have been recorded before and after the experiment with a control period. This would have ensured that the RF was the only variable applied.
The article does not explain the technical flaws they encountered in detail nor do they adequately explain the gaps in the weather data.
They claimed they were looking for "Non-thermal effects of RF" nut did not adequately record temperatures inside of the control and the test hives. They needed to adequately prove that their experiment was not heating the test hive. I also did not see the data on how much the bees had actually eaten when they were fed. They should have taken a much closer look at metabolic changes such as the level of activity in the hive.
The article was not peer reviewed to uncover the above flaws in the experiment. ==> Junk Science
If you read the "explorative study" in detail, it says that bees are so small, that their resonant frequencies (fs) are much higher than cell phones (375 GHz). http://www.bienenarchiv.de/forschung/2004_lernproz esse/Electromagnetic%20Exposure_Learning%20Process es.doc.pdf
Essentially, they don't have body part large enough to receive anything at 850 MHz where US cell phones operate and 1.9 GHz where US PCS phones operate.
Microwave ovens have are about 30% efficient and output at 2.45Ghz. Their output could be matched to a feedhorn. The problem is that they are difficult to modulate. You can use them to send chirpy CW and maybe AM. But they will not work to send a complex waveform like 64QAM which requires linear characteristics. Konrad WA4OSH
Having the wrong polarity only induces a 6dB loss. This may be significant to reject a minimallt interfering signal, but it's not enough to block a jammer.
Konrad WA4OSH
I don't usually reply to my own posts. However, take a close look at Intersil's response. It's poor engineering on the DARS providers part: http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?na tive_or_pdf=pdf&id_document=6513081279
Sirius's whole story is starting to sound like Global Crossing. Their previous CEO David Margolese bailed from the project last year and probably collected a small fortune to keep his mouth shut.
iamroot, It's 67.5 Mhz and obviously crappy receivers. The engineers just did not think too much about putting good front ends on their radios. Or... they are about to go bankrupt. They can't blame it on themselves for being 9 months late with their product. Of the two DARS bands, Sirius has the LOWER frequency band at 2320.0 to 2332.5 Ghz (at least 67.5 Mhz away where signals are way down in the noise according to my spectrum analyzer) and XM has the higher frequency licences at 2.3325 to 2.3450 Ghz which are much closer to the 2.4 Ghz band (only 50 Mhz away). The three Sirius satellites on an elliptical orbit are expected to transmit at 15KW signals. One of the three satellites is expected to cover the US at one time. However, this is not just a satellite service, but it's a ground-based system as well. They are building ground stations to prevent buildings and other obstructions from blocking signals in local areas. In many cities, Sirius and XM expect to cover the entire town with one omni-directional cylindrical antenna approximately 57" tall and 5" in diameter. Perhaps they tried to depend on too few ground repeaters in highly populated areas. Each service XM and Sirius have 100 channels a piece. It's interesting to note that XM which is directly adjacent to Sirius in its frequency allocations, and also having ground based transmissions is not expected to interfere with Sirius - right. XM will be transmitting at a much higher power lever (~10-100 watts ERP) from the ground-based locations. So why does XM not interfere??? Also, hams are licensed for much more power than part 15 on 2300-2310 and 2390-2450 and are much closer to Sirius's and XM's service than the ISM band. So quite possibly, hams could interfere with their systems as well - we are allowed much more power on these bands than what is allowed on the ISM band by part 15 users (4 watts ERP). My guess is that it won't be due to out of band operations, but probably due to Sirius's poor front-end design. BTW The 2.4 Ghz band has been and will be full of ISM stuff like 802.11, 802.11b, 802.11g (soon), HomeRF, Bluetooth, 2.4 Cordless phones, microwave ovens, security cameras, SCADA systems, door openers and dozens of other gadgets that have been there for years already. BTW cell phones use 800Mhz and PCS phones use 1.9Ghz. And should not interfere with their system. If their system is so great, why did their CEO David Margolese bail?? Konrad Roeder, WA4OSH Consulting Systems Engineer http://www.springswireless.com See http://www.fcc.gov/oet/spectrum/table/fcctable.pdf
I find their claim that the agregate sum of all part 15 use in the 2.4Ghz band is causing them interference a bit hard to understand. It's not like the cars are transmitting up to the satellite and the satellite needs to hear them. Their receivers have a problem rejecting adjacent channel interference. When you want to tune a signal from the satellite at -115dBM with an omnidirectional antenna, they get noise from everything in the area and have a bit of trouble rejecting signals that are in the -30 dBM region inside the same car (or most likely truck), or signals eminating from nearby buildings at -60 dBm? Here is some more background to consider... Sirius has the lower frequency band at 2320.0 to 2332.5 Ghz (at least 67.5 Mhz away where signals are way down in the noise according to my spectrum analyzer) and XM has the higher frequency licences at 2.3325 to 2.3450 Ghz which are much closer to the 2.4 Ghz band (only 50 Mhz away). Why is XM not complaining??? Ahhh they paid millions for their licenses and perhaps their receivers are wide as a barnyard door ...and their protocol is suceptible to interference? (more than XM?) Perhaps they were so late in the market with XM radio already selling and they can't afford to redesign their radios. And the radios with a better front-end would put their product at a disadvantage with XM?
I think Sirius is serious financial do-do. Sirius Radio service will be available nationwide by the third-quarter of 2002. (9 months later than XM) Until then, it's a ground-based operation. Furthermore, they have had trouble getting Ford and Chrisler on board. Both will offer the radios in '03. (XM has GM as a partner and is selling now) Sirius Radio reported a net loss of $57 million for third quarter '01. Losses are Sirius Radio has also publicly announced that they have enough cash to last until the fourth-quarter of 2002. Their insiders are selling their shares.
I get it -- call in the lawyers and eliminate all part 15. Yeah that's the ticket.
Konrad Roeder
Consulting Systems Engineer
http://www.springswireless.com