I tried posting earlier to get more information, but nobody responded. I still don't understand how these devices received a grant from a functional perspective.
Even if a "lab queen" was used, how did they manage to stay below the FCC part 15.107 / 207 limits for powerline conducted emissions? The lab queen still has to have the same circuit design as the device that will be marketed. Lab queens are only supposed to allow for relaxations due to manufacturing variability.
On what frequency are they operating? If they are below 30MHz, then are they taking a risk by staying below the part 15 powerline conducted limits? Even if they are above 30MHz, I would still think that they would have trouble testing a device to the 15.109 / 209 radiated limits.
Did they receive a waiver to allow this or are they just so far down in the mud that any unintentional radiator can stomp them out?
Does anyone know how these guys are able to comply with the FCC part 15.107 & 207 regulations on conducted emissions? What frequency are they using? If they are above 30 MHz, what about 15.109 & 209 regulations for radiated emissions? Are they taking a risk by staying below the regulatory limits or are they operating on a waiver of some sort?
I cannot use any calculator besides my HP48G (aka secret weapon) any more. If I have to balance my checkbook and do not have secret weapon with me, then I do it by hand. No TI calculator will work for me.
Except ham has number one priority. I believe that the part 15 rules are WAY too lenient. Any interference that you have seen from part 15 devices is proof.
More expensive receiver technology can't compensate for noise. It's like trying to get a perfectly clear picture of the stars through an expensive telescope.
This is not true unless you go really high cost. In most cases, the noise in question comes from the noise floor of the receiver, not ambient conditions.
When there is noise on the channel, overly tight modulation schemes wind up with too many errors and retransmissions to compensate for the increased data rate.
... unless you invest in more expensive receiver technology. At one to one comparisons, you are correct. I am not talking about one to one comparisons for equipment used in different bands.
It's 26MHz, but it doesn't matter. Wireless Internet has NO BUSINESS being there. It causes interference and makes it so that NOBODY ELSE can function there (ask anybody who lives near a Waverider site).
The FCC needs to allocate spectrum for this for everybody's benefit, not just those interested in wireless internet. If path loss is a concern, then raise the power or manufacture equipment that can handle modulation schemes that make operation in the proposed 700MHz band feasible. Either way, STAY OUT OF THE UNLICENSED BANDS. They belong to those who can share.
Shannon's law has nothing to do with modulation schemes. There is no theoretical maximum when modulation is left open. Yes, more expensive receiver technology is required to reach those data rates, but it is not impossible.
"Lower frequencies that can penetrate walls and trees aren't likely going to give you anything you'd consider broadband speeds. You might be able to get a couple Mbits at 900Mhz, but once you get more than a few people sharing it, it's not going to be so hot. To go even lower means less and less bandwidth available."
This is not entirely true. Lower frequencies will require more complicated modulaction schemes to get the same data rates, but it is still possible.
Also, we should be careful when using the word "bandwidth" when talking wireless Internet. In the quote above, I think that it is supposed to mean datarates. However, bandwidth from an RF perspective can also mean frequency range.
Increasing RF bandwidth used is another way to get around the lower frequency issues with datarates.
Either way, this stuff does NOT belong in 900MHz. Make it at 700MHz, 2.1GHz, or somewhere else that does not require band sharing. Wireless Internet causes interference and should be given its own spectrum. We are all consumers and band hogs should NOT be tolerated.
"It sounds like Ricochet is going to use the unregulated 900 MHz band"
That's all that we need. More high duty cycle devices filling up the 902-928MHz unlicensed bands. Something has to be done about these "digitally modulated" band hogs. It has been less than a year since the FCC loosened the restrictions in the unlicensed bands and stuff like this is already happening.
I myself have experienced first hand interference from these unlicensed wireless 900MHz devices selfishly rendering the band useless.
The unlicensed bands belong to those who can coexist. If you can't share, then go somewhere else.
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Even if a "lab queen" was used, how did they manage to stay below the FCC part 15.107 / 207 limits for powerline conducted emissions? The lab queen still has to have the same circuit design as the device that will be marketed. Lab queens are only supposed to allow for relaxations due to manufacturing variability.
On what frequency are they operating? If they are below 30MHz, then are they taking a risk by staying below the part 15 powerline conducted limits? Even if they are above 30MHz, I would still think that they would have trouble testing a device to the 15.109 / 209 radiated limits.
Did they receive a waiver to allow this or are they just so far down in the mud that any unintentional radiator can stomp them out?
Does anyone know how these guys are able to comply with the FCC part 15.107 & 207 regulations on conducted emissions? What frequency are they using? If they are above 30 MHz, what about 15.109 & 209 regulations for radiated emissions? Are they taking a risk by staying below the regulatory limits or are they operating on a waiver of some sort?
Lying in the digital age is a bad idea.
Why not? It worked for George O'Leary!
Vigilanteeism, however, is just malice operating under false pretenses.
Revenge of the nerds!!!
I cannot use any calculator besides my HP48G (aka secret weapon) any more. If I have to balance my checkbook and do not have secret weapon with me, then I do it by hand. No TI calculator will work for me.
Except ham has number one priority. I believe that the part 15 rules are WAY too lenient. Any interference that you have seen from part 15 devices is proof.
More expensive receiver technology can't compensate for noise. It's like trying to get a perfectly clear picture of the stars through an expensive telescope.
This is not true unless you go really high cost. In most cases, the noise in question comes from the noise floor of the receiver, not ambient conditions.
When there is noise on the channel, overly tight modulation schemes wind up with too many errors and retransmissions to compensate for the increased data rate.
... unless you invest in more expensive receiver technology. At one to one comparisons, you are correct. I am not talking about one to one comparisons for equipment used in different bands.
"The 900Mhz band is only what... 5mhz wide?"
It's 26MHz, but it doesn't matter. Wireless Internet has NO BUSINESS being there. It causes interference and makes it so that NOBODY ELSE can function there (ask anybody who lives near a Waverider site).
The FCC needs to allocate spectrum for this for everybody's benefit, not just those interested in wireless internet. If path loss is a concern, then raise the power or manufacture equipment that can handle modulation schemes that make operation in the proposed 700MHz band feasible. Either way, STAY OUT OF THE UNLICENSED BANDS. They belong to those who can share.
Shannon's law has nothing to do with modulation schemes. There is no theoretical maximum when modulation is left open. Yes, more expensive receiver technology is required to reach those data rates, but it is not impossible.
"Lower frequencies that can penetrate walls and trees aren't likely going to give you anything you'd consider broadband speeds. You might be able to get a couple Mbits at 900Mhz, but once you get more than a few people sharing it, it's not going to be so hot. To go even lower means less and less bandwidth available."
This is not entirely true. Lower frequencies will require more complicated modulaction schemes to get the same data rates, but it is still possible.
Also, we should be careful when using the word "bandwidth" when talking wireless Internet. In the quote above, I think that it is supposed to mean datarates. However, bandwidth from an RF perspective can also mean frequency range.
Increasing RF bandwidth used is another way to get around the lower frequency issues with datarates.
Either way, this stuff does NOT belong in 900MHz. Make it at 700MHz, 2.1GHz, or somewhere else that does not require band sharing. Wireless Internet causes interference and should be given its own spectrum. We are all consumers and band hogs should NOT be tolerated.
"It sounds like Ricochet is going to use the unregulated 900 MHz band" That's all that we need. More high duty cycle devices filling up the 902-928MHz unlicensed bands. Something has to be done about these "digitally modulated" band hogs. It has been less than a year since the FCC loosened the restrictions in the unlicensed bands and stuff like this is already happening. I myself have experienced first hand interference from these unlicensed wireless 900MHz devices selfishly rendering the band useless. The unlicensed bands belong to those who can coexist. If you can't share, then go somewhere else.