3550MHz to 3550MHz? Very small range of frequencies there!
US regulator the FCC will hand over another 100MHz of radio spectrum to unlicensed wireless users, just as long as they let someone know they're using it, as the White Space expands to fill every gap. The band runs from 3550MHz to 3650MHz, making it slightly larger than the 2.4GHz band used for Wi-Fi. It's currently occupied …
...plus illegal radio transmissions are, by their nature, easily tracked down.
This is only true in the case of consistent transmissions. We have a case in my neck of the woods (southern Maine, USA) where a certain individual has been transmitting at high power on emergency channels -- but only sporadically, and only when there's actually emergency traffic on those channels.
This is definitely illegal, and certainly immoral, as the net result has been the endangering of several lives. However, to date, tracking the individual responsible has failed due to the short-term sporadic nature of the transmissions.
I'm not intimately involved with the investigation, so I'm not sure that this hasn't been tried. I do know from reports, however, that the perpetrator doesn't seem to interfere with test or other non-emergency traffic, and a few times, as investigation intensified, the perpetrator went silent, only to come back once things died down again.
Steve Knox, Tomislav, et al.,
I'm deeply disturbed to learn that there is some one intentionally jamming emergency communications channels, and what's worse, only when there is an emergency occurring. I had originally read these comments about four hours ago, and only just now had the chance to reply. Your second post, Mr. Knox, makes me fear that one of my suspicions is correct; the perpetrator is somehow receiving information about the investigation. I must surmise that he or she is either currently involved in the agency or agencies using those emergency channels, or has a person or persons working in or with this agency or agencies, feeding information to the person doing the transmitting.
It seems to me that the most simple way to get around this problem would be to switch to a different type of transmission. The most effective solution would be going to fully encrypted digital voice communications, but budgets, and most probably legislation, would prevent that. A less expensive alternative would be switching from analog to digital (if you haven't already), or switching to a trunked system. Although, I should point out that even fully encrypted digital transmissions can fall victim to something as simple as a third party pressing their transmit key at just the right time, even if all they're using is an analog transceiver.
It seems to me that the best bet in finding this bozo would be if the agency or agencies could set up, at separate locations, DF receivers (receivers that also show direction) capable of logging the direction a transmission comes from, and the date and time. Then, after a case of illegal transmission during an emergency, those records can be checked against dispatch log tapes and interviews with the personnel involved to rule out the locations of legitimate transmitters. At that time, only the illegitimate transmitter's location will remain.
If some how the agency or agencies involved have the budget to do this - and I hope that they do - either a), the perpetrator will catch wind of this plan, and stop transmitting, thus solving the problem, or b) will continue to transmit either because he/she was not aware of the plan to locate him/her, or he/she wants to be caught.
I'm guessing that the agencies are police and fire/EMT, and that it's either at the local or county level, and that a local or county sized budget is why a solution like this has not been tried yet.
I sincerely hope that the perpetrator is caught.
But selling spectrum to one owner, for their exclusive use, could eventually become history, with moves like this one ensuring no-one has reliably utilised radio spectrum.
Licence Free "White space" radio is only OK if it's the ONLY thing on a band. It may be feasible at 3.5GHz and higher to share as propagation is increasingly "line of Sight" only on the higher microwave bands.
But below 2GHz it becomes increasingly a disaster and isn't workable at all at 700MHz.
See what the Mobile phone companies think about sharing their 800, 900, 1800 and 2100 MHz "White spaces"?
"Ofcom has said it's keen to hand over the 600MHz band for White Space use until it's auctioned off some time around 2018 - the beauty of White Space being that one can just ask the band be cleared and in a matter of hours every device can be switched out"
So, they are encouraging us to buy devices, which, with little warning or fanfare, will all stop working within a few hours of the database being deactivated? How will Mr and Mrs Bloggs know what has happened to their device? Joe Public has enough problems understanding TV/radio reception problems, or why their Wi-Fi or mobile phone doesn't work, or works intermittantly........
Yes, the device can find another frequency, but whereas it works happily at 600Mhz, will it still be able to establish contact at a different frequency? Presumably devices sold for use at 600Mhz will be expected to move into white space somewhere else in the TV band (470-800) - what if that space is full? Will a 600Mhz device be able to work at "other" white space frequencies (eg. the 3550megs that the FCC is talking about?)
Sometimes I wonder how much Ofcom understand about about radio spectrum and engineering......
--- hand over the 600MHz band for White Space use until it's auctioned off some time around 2018 - the beauty of White Space being that one can just ask the band be cleared and in a matter of hours every device can be switched out, making it ready for sale.---
First you build a house. Then you open it rent-free to all the residents of Ursofruct, (Kent?) Then you offer to sell a "beautiful, classic country mansion."
"White Space devices are required to contact an online database to check out local conditions prior to transmitting, so they can safely make use of bands which are currently verboten nationally but only filled locally"
Imagine that - someone will be able to track every wireless device centrally, because those wireless devices have to "check in" and "check out" their usage. Wow, makes it easy, doesn't it?
Federated authority through distributed routing protocols of the current internet is very resilient... not sure how this will hold up under war or natural disaster.
When given the choice between central authority and federated authority - I choose federated every time... because if there is a local failure, one always has the opportunity to move to get a new signal... very good for wireless technology... interesting political implications.
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