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Re: Monkey Brains
On Wednesday, August 22, 2018 at 8:31:27 AM UTC-7, John Larkin wrote:

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How odd; from here I can see eight networks that advertise, and there
may be some silent ones, too.  If  my home is any example, there's a smartphone,
tablet, Chumby, two blue-ray players, TiVO, Roku, and videocam that
connect at various times...dozens of talkers between those networks.

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Not anachronisms as long as they make money.  Cable systems are
currently losing customers to broadcast.

The charm of 'open vast spectrums' is lost on me; I'd want a bit of broadcast
spectrum for voice/data/video (DTV and FM suffice), and a parallel point-to-point
scheme that doesn't slosh data to any and all neighbors.   If net neutrality
were as strong a protection as postal regulations, I'd be happy with
a TCP/IP fast channel.

OK, I'm enough of a nerd to also want AM broadcast, if only because crystal
radios are SO cool.   Shortwave optional.



Re: Monkey Brains
wrote:

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But many cable customers are only buying internet service and not
paying for "channels." Watching a show at some specific time is so
last millenium.


--  

John Larkin         Highland Technology, Inc

lunatic fringe electronics  


Re: Monkey Brains
On Tue, 21 Aug 2018 18:21:19 +0100, Tom Gardner

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The FCC has a hard limit on maximum EIRP but raised it dramatically in
2013:
<http://stevencrowley.com/2013/08/11/fcc-boosts-power-limit-for-outdoor-60-ghz-links/
    The average equivalent isotropically radiated power (EIRP)  
    limit is raised from 40 dBm (10 watts) to a maximum of  
    82 dBm (158,489 watts) depending on how high the antenna  
    gain is. The peak power limit is 3 dB higher. The new  
    power limit is comparable to others the FCC has in the  
    fixed microwave services.This increase is expected to  
    enable higher-capacity outdoor links extending to about  
    one mile.

I would guess(tm) that you're thinking about the maximum power output
that could be delivered by a smartphone style handset at 60GHz. Todays
handsets typically deliver about 250 mW maximum RF output at 1.9GHz.
Mine seem to spend their time running at about 50 mW output. I
couldn't find anything on the efficiency of 60Ghz transmitters, but I
think it's a fair assumption that it would be much less than todays
smartphones.  It's likely that the battery is going to limit the
transmit power output to the low milliwatt range or less if it's a
phased array crammed into a handset.

However, if you don't care about miniaturization, there's always TWT
(traveling wave tubes) for V band that will deliver up to 200 watts
with 30-60% efficiency:
<https://www2.l3t.com/edd/products/twt_hp.htm
All that needs to be done figure out how to make it fit in a handset
or Small Cell package.


--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: Monkey Brains
On 22/08/18 04:31, Jeff Liebermann wrote:
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The limit I was referring to at 60GHz was simply that the
transistors have to be small relative to the wavelength, and
the consequent power density.

But that is from the memory of a conversation in 1996, and
that conversation was of a report by the 60GHz transistor
manufacturer. It was regarded as plausible by those with
more direct knowledge than me.

FCC regulations were irrelevant at that stage; indeed
they asked us to help set some!

Re: Monkey Brains
On Tuesday, 21 August 2018 17:00:10 UTC+1, John Larkin  wrote:
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only upto a point. 100x as many transmitters can only get you in the ideal case 100x the data throughput.


NT

Re: Monkey Brains
On 21/08/18 17:59, John Larkin wrote:
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Oh, wireless is certainly very useful.  I just don't think it is useful
for /everything/.

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Re: Monkey Brains
On Wed, 22 Aug 2018 10:13:51 +0200, David Brown

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Not for power, water, or gas. But why not one wireless network for all
data to your house? I'd love to get rid of phone boxes, dsl modems,
wifi routers, hubs, poking CAT5 and coax through walls, sprinkler
controllers, garage door openers, light timers, separate security
systems, scattered smoke and CO detectors, cable TV contracts and
wiring.

On the commercial side, even low voltage/data wiring is run in conduit
here. That's fabulously expensive and inflexible and ugly.

I'm always impressed by how many people refuse to consider progress,
and fight against speculation on what their own profession is capable
of. Most people spend their energy shooting down ideas instead of
playing with them.


--  

John Larkin         Highland Technology, Inc

lunatic fringe electronics  


Re: Monkey Brains
On 22/08/18 16:41, John Larkin wrote:
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Eggs in basket?
Security?
Physics of the propagation channel?

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Wouldn't we all, but that all has a different non-financial cost.

Re: Monkey Brains
On 22/08/18 17:41, John Larkin wrote:
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Again, I can agree that it would be great to have everything wireless.
And I agree that it is certainly useful and practical for many things.
Just not for all communication.

For many people, wireless /is/ the way they do all their data traffic in
their house.  They have a router (DSL, fibre, cable, whatever) and it's
Wifi to their telephones, pads, laptops.  You can do a great deal that
way.  But it is not good enough for everything.  It is simply not fast
enough, stable enough, or long enough reach - and this comes from
physical limitations.  Sure, you can get a wireless link that is fast
and stable enough for top-quality video - but that won't go through the
floors or walls.  Sure, you can have a wireless link that will reach to
the garage - but that won't be fast enough if you want to copy large
files around.  Sure, you can have wireless streamed video to 3
teenager's bedrooms - but that is for small screens, and they might get
problems if the surrounding flats are doing the same thing.

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You just have to understand there are trade-offs.  Often wireless /is/
the right way - but it most certainly is not /always/ the right way.


Re: Monkey Brains
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You should not confuse the use of wireless inside a home for local
area networking with the use of wireless for point-to-point outdoors
connections as described in this thread.  They are really different
things, although they unfortunately (partly) share the same spectrum.

Re: Monkey Brains
On 23/08/18 09:55, Rob wrote:
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I am not confusing them - but I wonder if John Larkin has been, in
thinking that because it is good for his internet connection at the
office we could use wireless for everything.

There are also point-to-many-point links, such as satellite TV dishes,
which are also very useful in their niches but can't be used for
/everything/.


Re: Monkey Brains
On 22/08/18 16:41, John Larkin wrote:
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The first link I found about security and some the applications
you mention. It outlines some of the hazards.

https://blog.compass-security.com/2013/02/advanced-metering-infrastructure-architecture-and-components/

If I had time I'd look at what Ross Anderson's group at the
University of Cambridge has written about the topic.

Re: Monkey Brains
On 20/08/2018 18:33, John Larkin wrote:
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Nice! We have that here on the Isle of Wight (small island off the south  
coast of England) Population ~140K. Only 150 MBps at the moment...

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Re: Monkey Brains
On Tuesday, August 21, 2018 at 7:29:37 PM UTC+10, TTman wrote:
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<snip>
  
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It's not that far off the south coast. When I was post-doc in Southampton, I played hockey there from time to time, and even took the hovercraft ferry over to the Isle of Wight when I missed the regular ferry.

It was a windy day, and got windier - the hovercraft flipped on the next trip.  

https://www.portsmouth.co.uk/lifestyle/heritage/fatal-hovercraft-accident-was-an-unenviable-first-1-2910611

--  
Bill Sloman, Sydney

Re: Monkey Brains
On 21/08/2018 11:52, snipped-for-privacy@ieee.org wrote:
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Small world eh ? We built fancy Laser Controllers for a spin off company  
formed by Soton Uni ex grads....
IOW is no match for Sydney :)

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Re: Monkey Brains
On Tuesday, August 21, 2018 at 9:43:38 PM UTC+10, TTman wrote:
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The Isle of Wight has its own charms. I grew up in Tasmania, which is rather larger - about the same size as Ireland - but only about three times the population (515,00 versus 140,500).

--  
Bill Sloman, Sydney

Re: Monkey Brains
wrote:

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How far is that hop? How does weather affect it?


--  

John Larkin         Highland Technology, Inc

lunatic fringe electronics  


Re: Monkey Brains

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Not sure about weather, I'm not on it. Island is ~14 miles wide by 7  
miles 'tall' . I think they have a few repeaters across the island as it  
is very hilly in parts.I guess it's affected by rain storms as is any  
other microwave link...No idea what the link frequency is but they use  
small dishes maybe 15" dia.

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Re: Monkey Brains
On Mon, 20 Aug 2018 10:33:59 -0700, John Larkin wrote:

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Spectrum business service, and they are charging me $119 / mo right now  
for 100 mbits/sec down and 4 mbit/sec upload.  The download is great, but  
I'd like to get more upload.  I get a HUGE runaround from Spectrum about  
it, but mostly they seem to say if I go up to $175/mo, I can get 100/10.
(These prices include one business phone line, too.)

So, I've been looking for alternatives, but in our area, there are VERY  
few options.

Thanks,

Jon

Re: Monkey Brains
On Mon, 20 Aug 2018 10:33:59 -0700, John Larkin wrote:

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Ah, looks like San Francisco area, only.  TOO bad!

Jon

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