zw123456

what is the optimal voltage based on empirical data ?

Right, agree. But then there is the tradeoff of the popularity and availability of 12VDC devices due to RV/Boating. But strictly from a technical point of view you are spot on.

There is some validity to using DC distribution within a building or domicile, it can make it cheaper and more reliable to have a central power supply and battery system.

That is not a new idea obviously, that exact approach has been in use in the telecom industry for decades. There is a AC feed to a system of rectifiers that converts the AC from the grid to -48VDC and continuously charge a string of batteries. There is a Generator that will go on automatically if the power from the grid fails and takes over.

The -48VDC is distributed throughout the central office to the equipment bays. There are a number of benefits to doing it this way, the batteries help maintain a constant voltage level and provide back up until the generator can fire up or if the generator should fail to start it buys you time to get it going.

For a home, I could see having a DC distribution system using USB 48V standard or maybe a 12VDC system with a wall battery and perhaps Solar system. Assuming that you could power all your devices off DC, it would eliminate the need for an Inverter. Most devices in homes today can be powered with 12VDC versions, with some exceptions.

It's an interesting idea.

Always thanks to Ken for all the fun "memory" lane stuff.

That board reminded me of an old PDP1 board from way back when I was doing undergrad in the 1970's and we had a "junker" PDP1 that no longer ran (replaced with new PDP8) but people would salvage things off it. It had that same old timer Resistor, Diode, Transistor type logic circuits on it.

Would love to see some of the old PDP's stuff reversed engineered if they have any of it around there. Ken if you take requests :)

This reminds me of back when I was at Bell Labs back in the 1980's and there was a "user manual" of how to crash the Unix OS on the PDP11's in our lab. The idea being if you just tell people how to do it they won't try to show how clever they were by doing it. Also, it was a warning what not to do, but it also discouraged anyone from thinking they found a new flaw or whatever.

Yup, it's an age old ham gag for sure. We were doing it to show off the power of our invention of course. The funny part was how when we demo'ed it for some exec's they sort of covered their privates when they saw that neon glow. It was in an anechoic chamber so there was of course no danger anyway. But it was still good fun.

There were a number of very interesting items in R17, the one I have been keeping an eye on since they started the study group on it is:

> Non-terrestrial networks (NTN): following the Release 16 study, Release 17 introduced 5G NR support for satellite communications. It includes two distinct projects, one focusing on satellite backhaul communications for CPEs and direct low data rate services for handhelds, and a second project adapting eMTC/NB-IoT operation to satellite communications.

Specifically, "satellite backhaul communications for CPEs"

i.e 5G from LEOS direct to a CPE, perhaps a small Starlink type antenna out the window?

Very interesting.

It's all about the watts baby.

When I was a kid I made an AM radio receiver with a safety pin and a piece of zinc and a crystal earphone.

Later in life, working on an experimental MW system at Bell Labs, a fun gag was to put a Neon lamp in front of the transmitter horn antenna and watch it light up when you switched on the transmitter, then nonchalantly say, oh ya she's working.

Very famous study https://en.wikipedia.org/wiki/Stanford_marshmallow_experimen...

Delayed gratification is hard, believe me, had my Dad not literally screamed at me to sign up for the 401K when I was 24 and entering the workplace, too many years ago to admit... Well, I am glad I had a Dad that screamed at me.

It always seems like a bad time to invest. But, if past is prescient, it is always a good time to invest.

ya, it was stupid, the interest was about $300 or something. I would have paid the original amount but I just screwed up and mis-placed the 1099. It was a gotchya game. I think this could be why people hate taxes so much, of course we all hate taxes but the way you do it matters IMO.

Exactly my complaint as well!

They could send me a monthly statement like my city government does. Instead, they wait a year to let me know I slipped up and then charge me interest. Guys, if you know I slipped up now you could have told me a year ago.

German efficiency!

I like it, my city government sends me a statement once a month, says you owe this amount for police, that amount for fire, some other amount for sewer and water, some amount for schools. Maybe I disagree with some of the amounts, fair to discuss, that's democracy. But they don't play that idiotic game the feds do, you owe a certain amount, if you guess it correctly, or if you on purpose short it but we don't catch you at it, then nothing happens. But if we randomly catch you getting it wrong then we fuck with you. I hate that.

Exceptional != Best

well, I am walking around free so, for sure you don't go to prison but you pay a penalty perhaps. In my case I just paid it. It was an honest mistake and they did not bust my chops over it, they did charge interest, which is stupid. But, fine, if your computer can figure it out why not just send me the bill monthly like my city government does?

Yup, dumb mistake on my part, so I track it better now. The point is, do I really have to do all this work tracking everything to guess which card they are hiding behind their backs. It's kinda dumb IMO.

ya, I am sure you are right, I get a bunch of them and I missed a small one. But whatever, the point is, they could just send me a statement.

I remember when I first started working at Bell Labs, way way back in 1978, I had just got my MSEE and had the world by the tail. But there was some old timers there that, I learned to really respect. They spoke more slowly than I did and sometimes stumbled a little. But, man, the knowledge there! It is something that stuck with me over the years.

Now, I am, I guess one of those old timers. But, I am pretty lucky to work with a lot great people and I try to remember that experience of mine and relate to some of the younger people that are a little quicker than me on some things. I feel that, I provide a lot of value still, and, I get feedback from a lot of younger people that helps confirm that for me.

I would advise, to try to convey your wisdom, don't try to mimic being young, be you, slower, but wiser perhaps. You have valuable experience, offer that for what it is worth and do not worry if you cannot find the perfect word or phrase, just share your knowledge, wisdom and experience.

ya, so why not just send me a statement once a month, the power company does that, the cell phone company does that, the city I live in does that, etc.

Just send me a statement, you made this, you get this much deduction for the other crap or whatever.

No stupid W2, W4 1040, bunch of mumbo jumbo from the 1950's that a few companies are ripping us off over IMO.

I have had that similar feeling and have joked around that Amazon is reading my mind. I go outside and see bird poo on my deck and driveway and they send me an add for a pressure washer. Wow, how did they do that, ESP? It sure feels like it, but no, they know I own a home (based on previous purchases, perhaps other things, but really they can tell by what I have bought before). It's spring, and what do homeowners do in the spring ? they pressure wash their decks. They send me adds for other spring home related things. But it sort of felt creepy for a minute until I thought about it.

A few years back I got audited, and it was called an "electronic audit" by the IRS. Which basically meant that they had their computer systems scour a bunch of the bank records and discovered that I had forgotten to claim a 1099 for some contract work I had. OK, so they sent me a computer print out and they had cross checked everything on my return electronically, my property tax deductions, my stock dividends so on and so on.

Ok, so if they can do all that automatically for an "electronic audit" why am I filing a return, just run that thing and send it to me and I can file an exception if there is something on it I disagree with.

I think the answer has already been identified in several other comments here, a heavy lobby effort on the part of Intuit, H&R and whoever else to keep it tricky and complex so you have to buy their B.S> software or services.

The basics are this, the lower the frequency because lower frequencies propagate better (https://en.wikipedia.org/wiki/Free-space_path_loss)

but...

you will get less capacity, because at the lower frequencies there is less spectrum (it is simple arithmetic there is 1000Mhz of spectrum below 1Ghz, but there is 100Ghz of spectrum below 100Ghz (setting aside the details about how it gets allocated etc.)

The amount of capacity you can achieve is based on Shannon limit https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theore...

it's the classic engineering trade off, better propagation vs. more capacity.

that is why the carriers want low, medium and high band in their inventory,

low is considered < 1Ghz, medium is considered 1Ghz - 10Ghz, high is > 10Ghz, roughly speaking

Both wired and wireless are regulated by the FCC, neither have net neutrality restrictions anymore, the went bye bye in the U.S. at least, a couple years ago and I seriously doubt it will come back ever.

> The FCC declared mm-wave a national defense priority and it is not subject to any local regulation.

I am not sure where you are getting that but mm-wave is absolutely still regulated locally just like anything else. The main difference is the size of the radios for mm-wave are small and go on poles and the FCC did set a price ceiling on what utilities can charge for pole space. But there are also low and mid-band small cells that go on poles as well. But the wireless companies absolutely still have to get local permits to install any wireless system on poles or pretty much anything.

Me too, nothing beats fiber if you can get it. I used to have Fios where I used to live and nothing beats it, but where I live now, you cannot get any fiber to the home, but I can get the mm-wave 5G and that is a pretty close second, the speed on my mm-wave is actually faster than the Fios I had before but now there is NGPON2 which is the new tech behind it and that can actually get you to 10Gbps. Fiber will always be faster most likely.

I agree with you on this. I search for tech topics a lot and google offers an option to search "scholarly articles". I like that option as sometimes a tech term gets confused with something else. It would be great if there was a way to select from some check boxed, like an advanced search, "search only for semiconductor datasheets" or "search all Jazz music" or upload a picture and "identify an insect" (agree that does not work well yet) or whatever someone might be interested in.

The question is if such an approach would lure a lot of people away, I could see an entry angle might be a front end to google with an app that does that.

You make an interesting point because here Verizon and ATT are local telcos as well so they can potentially cannibalize some of their own customer based in their serving areas, but both have had wired broadband service options in their serving areas which as stalled in terms of growth over the past few years. So I think they are looking at wireless, which is a cash cow for them, and probably figure they may win more customers from the cableco in their serving areas with a wireless option that does not require any installation or retrofit work at their homes. Bringing fiber into the home can be expensive, and DSL (copper) will not get you the speeds people are looking for these days for broadband service.

You are right, this is all a very U.S. skewed view of things. I do not know the European market but my guess is those providers are probably also looking for some revenue boost from 5G.

Yes, Tmo is catching up with ATT and VZ on quality, the main reason they bought Sprint (remember them) is because Sprint had a shit ton of spectrum but they weren't building it out because they were capital starved (for a bunch of reasons). So now, TMo has the most low and medium band spectrum and they are catching up on build out. Vz has the most spectrum if you include the mm-wave, but it's difficult to build out.

All the bandwidth competition is a good thing for the consumer and hopefully some cool stuff gets developed to take advantage of it.

Basically, 5G introduces some new technology that increases the so called spectral efficiency (bps/hz) that is how much tput you can deliver over the allocated spectrum. 5G introduces things like mm-wave tech using phased array antennas, better massive MIMO etc.

But even with the tech, it's probably not enough to handle the demand they are hoping for, hence they spectrum buying spree they have been on lately.

It goes back to the Shannon law talked about here, you either have to build more cells to make the signal better (better signal lets you pack more bps per hz, or you need more spectrum. Both are expensive, and most of them are doing both.

One of the primary reasons that carriers are interested in 5G is because for the last decade they have been swapping spit (trading customers between each other, carrier A lowers the prices and take customers from carrier B, who responds in kind and takes from carrier C who responds with a marketing campaign with some deal on a phone etc. and etc.)

What they all are craving is new revenue. Once everyone who wants a cell phone, has one, it becomes a commodity item and service and that means, if anything, one price war after another. This is why they are interested in 5G and MEC (Mobile Edge Cloud) they are looking for new revenue. Right now, as part of the 5G push is the idea of wireless home internet, which is basically just a wifi AP that connects to the internet via the wireless network. To do that of course, you need a lot more capacity, 5G offers that to some extent, but realistically you need a ton more spectrum, which is why you have seen a spate of auctions lately.

Make no mistake here, 5G Home internet is most certainly not a cost savings approach for the carriers, they are literally spending billions on it, in hopes of luring customers away from the cable cos and telcos or other wired providers. Will it work? Perhaps. Time will tell. But to be sure, in my view, this is very good for the consumer of internet services, it will almost assuredly provide the customer with a lower cost per Mbps due to increased competition particularly with all the LEOS (Low Earth Orbit Sats) also in the mix.

This reminded me very much of the old mag core memory from early days of computers https://en.wikipedia.org/wiki/Magnetic-core_memory

Hi, another 5G UW user here, I am getting pretty consistently 1.8Gbps to 2.1Gbps on mine. But I played around with the CPE placement quite a bit. I don't know if you are able to try that. UW will drop you down to lower speeds or a lower band if the mm-wave signal is not good. mm-wave is really touchy dues to the small beam size.