Unlimited data SIM plans are not uncommon in the UK and other countries. I have unlimited data on mine (obviously!) and some months I have exceeded 1TB in usage.
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U.S. Airlines Warn of 'Catastrophic' Crisis With Impending 5G Rollout, AT&T and Verizon Agree to Delay Around Airports
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Unlimited data SIM plans are not uncommon in the UK and other countries. I have unlimited data on mine (obviously!) and some months I have exceeded 1TB in usage.
Upload speeds with 5G are pretty much determined by how your carrier has configured their equipment.
Unlike LTE, which is mostly FDD-based (separate blocks of frequency for uploads and downloads), 5G NR uses TDD (upload and downloads share the same band using time division).
TDD gives the carrier more flexibility to prioritise downloads over uploads if that’s what they want, or alternatively to balance uploads/downloads more evenly based on demand.
Does anyone want to check my math on this, because these numbers are kind of amazing to me.
In my post above to @MacBH928, I was going through the power differences between WiFi and 5G and I pulled some numbers from the Report and Order:
3280 Watts/MHz in rural areas
1640 Watts/MHz everywhere else
That seemed crazy high to me. So I started looking around the web and eventually found an earlier letter AT&T and Verizon sent to the FCC offering to reduce their transmit power levels as a concession to the FAA. Their concession, for 6 months, was to reduce their transmission power to 62dBm/MHz up to the horizon with a taper function above the horizon. They offer further reductions within 1000 feet of the runway.
But I started doing the math— the reduced power level they’ve agreed to is:
10^((62-30)/10)= 1585 Watts/MHz
That’s 444kW of output power assuming they use the full 280MHz of bandwidth in the 3.7-3.98GHz bandwidth they’re licensed for. 158kW if they limit transmission to below 3.8GHz. Am I doing that math right?
I know these are EIRP numbers, but I’m not interested in the conducted power to the antenna, I’m thinking about the power seen by anything in the antenna pattern.
That’s more than most FM radio stations. If they go to full power after the 6mo window, it will be significantly more than any FM radio station. WBCT transmits at 320kW ERP, which is 525kW EIRP.
@827538 had been making a big deal over the fact that there’s currently a satellite band next to the altimeter radars. That seemed like a particularly weak argument to me, because this band is for downlinks from solar powered geostationary satellites 36,000,000 meters above the equator and the 5G towers are only agreeing to keep their terrestrial transmitters 1000m away for the next 6mos.
That November letter also agrees to temporarily limit their power flux density over airports to -30dBW/m^2/MHz so now I’ve got numbers to validate my assumption with. Part 25.208 limits power flux density at the earth to -142dBW/m^2 in a 4kHz bandwidth or less depending on elevation.
Again if I’m doing my math right:
C-Band 5G is about 1 x 10^-3 W per square meter per MHz
FSS downlink is about 6.3 x 10^-15 W per m^2 per 4kHz
or 1.6 x 10^-12 W per m^2 per MHz
So the temporarily reduced power levels look to be 634 million times higher than what the limits were when the radar was designed. When the restrictions are removed, the numbers will be well over a factor of a billion.
In my post above to @MacBH928, I was going through the power differences between WiFi and 5G and I pulled some numbers from the Report and Order:
3280 Watts/MHz in rural areas
1640 Watts/MHz everywhere else
That seemed crazy high to me. So I started looking around the web and eventually found an earlier letter AT&T and Verizon sent to the FCC offering to reduce their transmit power levels as a concession to the FAA. Their concession, for 6 months, was to reduce their transmission power to 62dBm/MHz up to the horizon with a taper function above the horizon. They offer further reductions within 1000 feet of the runway.
But I started doing the math— the reduced power level they’ve agreed to is:
10^((62-30)/10)= 1585 Watts/MHz
That’s 444kW of output power assuming they use the full 280MHz of bandwidth in the 3.7-3.98GHz bandwidth they’re licensed for. 158kW if they limit transmission to below 3.8GHz. Am I doing that math right?
I know these are EIRP numbers, but I’m not interested in the conducted power to the antenna, I’m thinking about the power seen by anything in the antenna pattern.
That’s more than most FM radio stations. If they go to full power after the 6mo window, it will be significantly more than any FM radio station. WBCT transmits at 320kW ERP, which is 525kW EIRP.
@827538 had been making a big deal over the fact that there’s currently a satellite band next to the altimeter radars. That seemed like a particularly weak argument to me, because this band is for downlinks from solar powered geostationary satellites 36,000,000 meters above the equator and the 5G towers are only agreeing to keep their terrestrial transmitters 1000m away for the next 6mos.
That November letter also agrees to temporarily limit their power flux density over airports to -30dBW/m^2/MHz so now I’ve got numbers to validate my assumption with. Part 25.208 limits power flux density at the earth to -142dBW/m^2 in a 4kHz bandwidth or less depending on elevation.
Again if I’m doing my math right:
C-Band 5G is about 1 x 10^-3 W per square meter per MHz
FSS downlink is about 6.3 x 10^-15 W per m^2 per 4kHz
or 1.6 x 10^-12 W per m^2 per MHz
So the temporarily reduced power levels look to be 634 million times higher than what the limits were when the radar was designed. When the restrictions are removed, the numbers will be well over a factor of a billion.
Speeds are determined by bandwidth, and how efficiently the radio technology makes use of that bandwidth, not by frequency.
We tend to associate higher frequencies with higher speeds because there is more spectrum (or radio “real estate”) available at higher frequencies. That is, it’s much easier to find an available 100 MHz block of spectrum at 5Ghz than it is at say 800 MHz!
However, a 100 MHz channel at 5 GHz will not be any faster than a 100 MHz channel at a lower frequency. It’s just that you’re more likely to have that channel at 5 GHz - at lower frequencies you’d usually have to settle for a smaller one.
If every cell tower/transmitter used that kind of power, operators would have some astronomical power bills!
But the actual figure is much lower than that:
“telecommunications equipment supplier Huawei estimates that a typical 5G site needs around 11.5Kw of power, around 70 percent more than a 2G/3G/4G base station”
Source:
I can't argue with you because I do not know much. All I understand is that longer waves have less frequency(slow) but can travel further (car radio) . Shorter waves are closer together(faster) but travel shorter distance (Wifi).
@Analog Kid
are you saying if the router was setup to consume 8W per hour it will travel further and faster? Who doesn't want that? why limit to 4W?
This way many people will skip on home internet and just use personal hotpot for home internet. I checked BT site, which I believe is the most dominant telecom in UK, and their highest tier is 100GB/month. What am I missing? [LINK]
----
Also they seem excited about fiber, has it just arrived to UK? Fiber is old news, there are videos on youtube about Google Fiber from like 10 years ago
I think you’re confusing EIRP and conducted power. EIRP is the effective isotopic radiated power. It is the power an antenna would need to be radiating if the power measured was the same every where. For a cell tower it is inefficient to radiate power into space and into the ground, so directional antennas are used.
For example, WiFi is allowed 1W conducted into a 6dBi antenna, which turns out to be 1W * 10^(6/10) = 4W EIRP. There is 1W of power going to the antenna, but it‘s strength inside the antenna pattern is essentially 4W.
When you say “the actual figure”, you mean an estimate of conducted power based on another county’s standards.
I’d argue the FCC part 27 limit of “an equivalent isotropically radiated power (EIRP) of 3280 Watts/MHz” is the permitted figure:
and the number of “62 dBm/MHz” published by AT&T and Verizon is the “actual figure” for US, C-band 5G:
Relinked in case you didn’t notice the embedded links above.
Your reference also included this estimate ”transmitting in the 3.5GHz frequency waveband will need 14kW on average and 19kW at peak load”. I’m not sure if that’s referring to the CBRS band in the US, but in that band you’re permitted a maximum of 40MHz per carrier and the power limit is lower (eventually up to 37dBm/MHz). The 3.7GHz band has a maximum of 280MHz per carrier and the carriers are temporarily holding their power down to 62dBm/MHz, but it will eventually go up to over 65dBm/MHz.
So if scaled for bandwidth, at least, a 280MHz tower would require 133kW to operate. That would imply an antenna gain of 10*log10(444/133)=5.25dBi.
The 444kW EIRP number doesn’t seem unreasonable in that context, does it?
You’re right that lower frequencies are longer waves, but the wavelength and frequency don’t affect how far they travel. It can affect how well they travel through obstacles, however. They all travel the same speed, but if you’re using more waves at once you can carry more information. Maybe an easy way to think of it is this:
If you have one frequency, say 1Hz, you can turn that wave on and off. That information will travel at the speed of light, but it will only carry one bit (on, or off). If you have two frequencies, 1Hz and 2Hz, you now are using more bandwidth but you can turn them both on or off separately. They still travel at the speed of light, but you can carry 2 bits (1Hz on and off, 2Hz on and off) and can the numbers 0-3 in the same amount of time.
It doesn't matter if the frequencies are 1Hz and 2Hz, or 1,000,000,001Hz and 1,000,000,002Hz. You still have two signals you can turn on and off independently, so you can carry 2 bits.
Frequencies don’t have to be integers, so 2.317Hz is a legitimate frequency, and when you turn them on and off you’re actually adding more frequencies to the signal because of how frequencies multiply, but maybe that basic explanation explains why if you’re using more bandwidth (more frequencies) you can send more data more quickly.
It doesn’t travel faster (it still travels at the speed of light), but it can carry more data more quickly.
Data rate (what I think you mean by speed) is limited by the Shannon Hartley theorem:
DataRate <= Bandwidth * log2(1+ SignalPower/NoisePower)
So the two obvious ways to improve data rate is more bandwidth or more power. Bandwidth isn’t one frequency, but the range of frequencies you’re using. When we talk about 2.4GHz WiFi, for example, we mean a group of frequencies near 2.4GHz.
So yes, if you could put 8W of power out on WiFi, you’d be able to run higher data rates and longer distances. As far as who doesn’t want that, it’s your neighbors. The more power you have, the more interference they have to put up with. So the FCC has limited power output for WiFi like technologies in those bands to 4W.
The other thing to notice is the less-than-or-equal to in the equation— it’s a theoretical limit. Another way to improve data rate is to improve the way we modulate and encode data in the signal and share the channel with multiple devices to make the DataRate closer to the limit. There have been enormous improvements since the old 802.11a/b days, for example— this is one of the reasons WiFi keeps getting faster with each generation even if the spectrum and power don’t change much.
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So much for it being delayed around airports. Here's the current ATIS, at KLAS (Harry Reid Int'l Airport, Las Vegas):
Wash/rinse/repeat for all other major airports. What I've seen for those NOTAMs is this:
So there are multiple Airworthiness Directives out for this, let alone this NOTAM.. plus it's in effect for the next 2 years, so this is going to be a brutal rollout of 5G, especially for any aircraft, not just airlines.
BL.
Wash/rinse/repeat for all other major airports. What I've seen for those NOTAMs is this:
So there are multiple Airworthiness Directives out for this, let alone this NOTAM.. plus it's in effect for the next 2 years, so this is going to be a brutal rollout of 5G, especially for any aircraft, not just airlines.
BL.
Is that current? I don't know how to read those notices, but this caught my attention: "CREATED: 13 JAN 07:39 2022". I think that date is before the carriers agreed to changes in how they'd roll out.
Yep. all of it is current. the NOTAM (Notices to Airmen) was created on 1/13/22. The NOTAM went into effect in 1/19/22. The expiration date of that NOTAM is 1/19/2024.
This isn't relative to when the carriers would roll things out, but for when all pilots need to be aware of what is happening or going to happen in relation to what the carriers are doing. I'll translate:
AD AP RDO ALTIMETER UNREL. AUTOLAND, HUD TO TOUCHDOWN, ENHANCED FLT VISION SYSTEMS
TO TOUCHDOWN, HEL OPS REQUIRING RDO ALTIMETER DATA TO INCLUDE HOVER AUTOPILOT
MODES AND CAT A/B/PERFORMANCE CLASS TKOF AND LDG NOT AUTHORIZED EXC FOR ACFT
USING APPROVED ALTERNATIVE METHODS OF COMPLIANCE DUE TO 5G C-BAND INTERFERENCE
PLUS SEE AIRWORTHINESS DIRECTIVES 2021-23-12, 2021-23-13. 19 JAN 05:01 2022 UNTIL
19 JAN 05:01 2024. CREATED: 13 JAN 07:39 2022
Airworthiness Directive: Autopilot radio altimeters unreliable. Autoland, HUD (Head-up Display) to touchdown, Enhanced Flight visions systems, Helicopter operations requiring radio altimeter data to include hover autopilot modes and Category A and B performance class takeoffs and landings not authorized except for aircraft using approved alternative methods of compliance due to 5G C-band interference. Additionally, see Airworthiness directives 2021-23-12 and 2021-23-13.
Basically, any radio-based altimeter readouts, all autolands, any HUD devices down to landing, any enhanced vision systems, Helo ops that use radio-based altimeter readouts, hovering autopilot modes, and those particular takeoffs and landings are not authorized unless they are using approved alternative methods. All of this is because of 5G. The problem is that while almost all aircraft are capable of using ADS-B for altitude readouts, as a backup all aircraft use radio-based altimeters for readouts for indication of altitude.
In short, the FAA is preparing all pilots for what could happen because of 5G ahead of the main rollout; in fact, that rollout is supposed to be happening, except for around major airports. Unfortunately, it appears that it is already happening because these notices are now out for every airport, major or otherwise.
BL.
The issues with the major web sites is the limit on web hosting, not download speed. That's why Meta and Twitter uses a lot of Amazon Web Services (AWS) web server farms, though alas we've had the rare failure of a server farm with disastrous results.
Data rates are mostly driven by available bandwidth and modulation techniques. Higher carrier frequencies typically come with more bandwidth, thus higher data rates. But also consider that within any given bandwidth, the signal modulation techniques also allow much faster data rates (3G, 4G, and 5G all have different modulation schemes, even within their respective classifications).
He is a specialist in Chronic Fatigue Syndrome, multiple chemical sensitivity, and the effects of low-intensity microwave frequency electromagnetic fields (MWV-EMF) on the human body. In other words a pseudo science wackadoodle
I can't respond to this the way I want to without getting kicked off the site.
This important topic deserves an update.
Turns out AT&T and Verizon delayed implementing their 5G C-bands near airports until July 2023 and the FAA gave all aircraft until February 2024 to "be equipped to safely operate in the vicinity of 5G C-Band wireless signals."
And it looks like the airlines came in before the deadline!
Source: https://www.faa.gov/5g
Turns out AT&T and Verizon delayed implementing their 5G C-bands near airports until July 2023 and the FAA gave all aircraft until February 2024 to "be equipped to safely operate in the vicinity of 5G C-Band wireless signals."
And it looks like the airlines came in before the deadline!
Source: https://www.faa.gov/5g
Thank you for posting that update here - very good information!