In other words
My super magnificent 'Thing' is better than your (putrid little) 'thing'
What these tests don't bother to ask is 'do the users notice?'
Qualcomm is getting ready to ship one of the relatively boring bits of the 5G puzzle – well, perhaps boring for you, but fascinating for electronics geeks: a compact transceiver/antenna combo that fits inside phones to provide 5G millimetre-wave communications. Mm-wave transmissions are a crucial part of ultrafast next- …
"'do the users notice?'"
Since the radio spectrum is always shared, achieving higher bit rates and throughputs per channel implies that they can support more customer per channel. This would mean more potential revenue for cell operators and a better data experience for customers in congested areas.
After all, one meter is 1000mm, so . . .
That said, the custom when using the mm measure is to deal with a few of them, unless you're in the construction business when practically everything is measured in mm, even if there's 250 of them. Looks like the comms business is using the same approach.
isn't it (IUPAC?) convention to use 10^3 scales, ... so millimetres, metres, kilometres, but never centimetres?
On schematics of almost everything, its generally best to keep all measurements in a single unit... in fact, in the box of details found at the bottom, it should specify what the units are...
Aerial designs are fundamentally decided by the wavelength, about 300/(Freq in MHz) metres.
Then gain. Higher gain are more directional once you get past the gain of a 1/4 wave whip. Omni-directional aerials have poor to terrible gain, especially if smaller than 1/4 wave and not in free space.
Frequencies below 900MHz give progressively too much range and poor control of cell size, so poor frequency reuse. The channel size and number of channels is limited. Frequencies above 2.5GHz are progressively poor range, more line of sight and useful only in open plan offices or roof top point to point links.
Speed is related to channel size and signal to noise (power, interference, more aerial gain = more directional). Basically you are very limited in aerial gain (usually negative) due to handset & needed omnidirectional, you are very limited in power. So the signal to noise can't be much different to EDGE on GSM (0.2MHz Channel), or HSPA on 3G (5MHz channnels) or LTE /WiMax on 4G (Up to 20MHz channels). See where the speed is coming from?
The 5G is about integration of bands, infrastructure and logical operators (RAN). Not more speed in the same channel size, nor more bands. More bands are an effort by regulators to make more money and higher ones by Mobile to replace "free" WiFi.
Only the new 2.3GHz and 2.5GHz bands are much use for cellular mobile (3G & 4G are already on 2.1GHz and the old 1.8GHz and 900MHz (0.9GHZ) that used to be GSM only now have 3G and 4G too, depending on country/location.
So can we all ignore the "5G" hype. Almost all of it is totally misleading.
Of course an aerial for a higher band is small!
28GHz is garbage for mobile. Nice for a pair of dishes with LOS, or for up to 10km, a panel array of aerials about 10cm x 10cm x 2cm on your chimney. Totally useless for a handset, except with a pico base-station on the ceiling in each room.
I've a lot of 10GHz terrestrial gear and worked with Ku and Ka band satellite gear. I was working on projects 12 years ago using these bands.
Took me a while but now I see what you're getting at. You're saying that you're smarter than all the comms engineers at Mediatek, Qualcomm, and Intel, and all the mobile network base station equipment manufacturer engineers in East Asia, Europe, and North America.
“Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.” should actually have been phrased as “Only two things are infinite, the universe and *the human ego*, and I'm not sure about the former.”
Yes, yes, yes, etc, but no. Kind of. It depends.
I very much doubt that they're planning on replacing all the current 4G spectrum with 25GHz+, but then again I'm not an industry 'expert'.
What I would imagine is that there will be a high number of relatively very small 5G cells, covering anything from a patch of street to an open office area; small because of the inherent frequency limitations, but fast.
To complement this, 4G LTE will carry on alongside, to fill in the larger yet sparsely-populated spaces and also the numerous areas that don't have dedicated 5G cells. I would hope that this would also mean that the 4G cell bandwidth will be less congested, which ideally would mean better service. I've long lost count of the number of times in Central London that I had full 4G+ signal and yet I couldn't get any data through.
It'll be a small miracle to see clients roam between 5G & 4G cells seamlessly though, and for the telcos to actually provide the required backhaul to each cell...
Mage claimed, "Frequencies below 900MHz give progressively too much range and poor control of cell size..."
It's quite trivial to (conceptually) reach over and turn down the RF power (at both ends). There's no reason why the range can't be dynamically controlled to be whatever is required. I understand that the mobile end is typically limited to something like five steps, as remote-controlled by the network. In principle, it could be infinitely adjustable.
In summary, the range can be adjusted as required to whatever you like. This applies to any RF link where it's Line of Sight and internal noise floor (i.e. VHF and up; HF has too many wildcards, but isn't applicable to this discussion anyway).
PS: Antennas can be dielectrically loaded, hugely. Thus the phased array in a very tiny package.
Mage noted: "Omni-directional aerials have poor to terrible gain..."
Omni-directional antennas don't have to be isotropic. An omni antenna can concentrate the signal along the horizon to provide up to moderately-high gain and signal at all azimuths. Classic example is the vertical collinear array.
An isotropic antenna is the one that illuminates the entire sphere equally. And by definition thus provides 0dBi gain in all directions.
For mobile communications, where the platform (human hand-held phone, aircraft, or spacecraft) is tumbling around in all directions, then high gain antennas on the platform are generally a bad idea. The exception is where they're dynamically and actively controlled to electronically steer the signal in the desired direction. It's complicated but increasingly feasible.
The far end (the tower) can use an electronically steered antenna to focus a high gain signal on the mobile user. If they're far away, then the direction is stable. If they're close, then it doesn't matter.
It’s still all non-ionizing radiation, so it won’t cause cancer. It would only cause ill effects if you’re standing next to a cell tower broadcasting at 30+ Watts. 5G is more about more plentiful cell sites all with a lower average power, so they should be even better than the current situation, not worse
"The trouble is that mm-wave communications don't have much range, are quite narrow and focused, and can't penetrate walls and get into buildings"
So using 5G indoors will not work. You can't even get a 3G signal in Tesco!
Should be a market opportunity for 5G repeaters somewhere.
BR mentioned, "...wireless prices in Canada..."
Worse than the price, Rogers occasionally forgets to plug the Ethernet cable into the "tower". So I sit here with a lovely 4G signal with 4 or 5 bars, and essentially zero data throughput. Being in the forest, I don't suspect heavy data usage from all the spruce trees. So I'm left to conclude that Rogers are idiots.
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