a a snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:
Retarded word salad? MMHS huh? wow... better inform the world man or we're all doomed.
Idiots like you?
Oh boy! Both immediate AND serious! Oh my!
More word salad.
a a snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:
You are an idiot. Get on Amazon, and uy a block of salt. You know... a deer lick.
Then start licking it.
Exposure to you and your inane utter stupidity is a health danger. You should lose your Internet hooks.
a a snipped-for-privacy@gmail.com wrote in news:ef32ee2f-7d16-4146-a49f- snipped-for-privacy@googlegroups.com:
You are an idiot, and someone should come by, and stuff your head into a microwave oven that has had the door switch defeated and turn it loose on you for a spell.
On a sunny day (Sun, 28 Aug 2022 12:41:15 -0700 (PDT)) it happened a a snipped-for-privacy@gmail.com wrote in snipped-for-privacy@googlegroups.com:
Yea, and there is always a bit microwave leakage from your oven too. Man the whole house is hot here, I have a cheap RF detector from ebay that goes into alarm mode upstairs, probably WiFi from the neighbors or the radar
But being a radio ham ... now uplink to that Oscar100 ham satellite also needs about 2.4 GHz high power (few hundred Watt for video DVB-S2).
So, am still around getting closer to 80 years now :-) Going to a market in the US is more dangerous it seems, chances are you get shot! Or you get robbed for your smartphone! And now Chernobyl lurking from Ukrain...
How is this relevant to microwave transmissions? Band 14 is at around 700MHz, in the UHF band that has been used for terrestrial television transmissions for a very long time. Of course the power level used for band 14 transmissions is vastly lower than traditional TV transmitters, so it is even less relevant.
John
If "a a" went anywhere near a psychiatrist he'd promptly get locked away for his own protection.
"A a" may not be actively dangerous to other people, unless they take his lunatic delusions seriously, but he must be a danger to himself.
While space based systems are useful for planes, cruse ships and very rural villages, this is not usably for delivering broad band internet to even modertely densely populated areas.
The real problem is the available number of radio frequencies (RF) available. You can not allocate a single frequency worldwide for a single signal. The same frequency must be reused at different locations for other signals. By limiting a signal to a small geographical area, the same frequency can be reuse more times, thus increasing the number of signals word wide.
This is the idea behind all cellular systems. In fact the same principle was already used with TV-channels and audio broadcasts since the 1920's.
A single broadband internet connection requires similar RF-bandwidths as a traditional TV-channel (5-10 MHz) which 100 km coverage. If there are a million internet users in that area, all RF frequencies would have been overloaded a long time ago.
To allow such per user bandwidths, the cell size will have to be reduced significantly. In 5 G (and 6 G), the cell area could be as small as the area illuminated by a single street lamp. This has also the advantage that the hand set transmit power can be reduced, minimizing battery consumption.
In satellite internet using phased arrays in some MIMO (Multiple Input Multiple Output) will help make small multiple beams and hence produce smaller cell sizes, the satellite antennas sizes proposed are too small so it is hard to make cell sizes much smaller than 1 km. Thus, only a limited number of customers can be serviced in that cell.
You can pump a terabit/sec over a small fiber bundle, so a microcell can have all the bandwidth it needs. And it can ricochet to a bunch of other overlapping microcells. Cheap dishes can spread data locally too.
Satellite internet is useful to really rural locations, but I'd expect the economics to be bad unless government funded.
About half the world's population doesn't have internet access. Satellites could get a lot of them low-bandwidth connections.
For more than two decades it has been possible to transfer that amount in a _single_ fiber using DWDM (80 wavelengths with 10 GB/s each). At certain IR wavelengths, the fiber losses are so small that you require an optical (Erbiun) amplifier only every 100 km. Nice for making transatlantic optical cables.
The losses at IR are much greater in free air than in ffibers due to the atmospheric gases.
IR distribution might be viable within a room or above your seat in a pane.
How do you constantly aim the antenna when either station is moving ? I haven't hear of MIMO antennas for IR
Since about 70 % of Earth is covered by water, the LEO satellites spend most of the time over water, servicing planes and ships. During part of the orbit when it is over land, it can service rural areas.
When the paying customers are in planes and ships, third world countries van be served by excess satellite capacity cheaply.
So we can be sure that when something breaks, everything is down. A bit of diversity is good.
Jeroen Belleman
On a sunny day (Sun, 04 Sep 2022 07:28:15 -0700) it happened snipped-for-privacy@highlandsniptechnology.com wrote in snipped-for-privacy@4ax.com:
It is not so easy to protect satellite links against eavesdroppers Anybody can read your stream, and many will know how to decode it, Some internet links on the current satellite are even unencrypted, I can see and record what people download (tried it). But I cannot select what I want to see unless I have the password and encryption interface (usually users select content via a land line / phone line).
Do you really think that around 200Mbit/s downlink, around 30ms latency and the ability to stream multiple video channels at once is slow and a dead horse?
How fast is your internet connection then?
John
Who said anything about broadcasting. I am referring to individual users watching a video of their choice at the time they choose. Multiple family members can watch different HD videos at the same time all over a single satellite link. I agree, it has little to do with TCP/IP packets. Most streaming protocols are build on top of UDP/IP packets.
It seems to work remarkably well.
Per single user.
That would be a bit extreme for one user. Even those lucky people who have
1Gbit/s fibre will seldom find servers that can deliver anything like such speeds.John
You would need to ask Starlink that question as I don't know the answer. Alternatively, there is probably enough information out there to work it out. What I am giving you is real data from one user in the UK which clearly contradicts your claims about Starlink. I can ask about uplink speeds, but probably not until Wednesday. The user I know will undoubtedly have measured them. Something to bear in mind is that there will never be a situation where all the users are downloading at 200Mbit/s at the same time. The whole internet (and global telephone system) rely on the fact that most users only need peak bandwidth for a very small proportion of the time. So long as the system bandwidth is wide enough compared to the peak bandwidth allocated to any one user the statistics of multiple users allow a great deal of smoothing out of peak requirements.
John
Starlink are not actually using multi-hop laser links in space at the moment. Connections go via one satellite at a time to a nearby ground station. The locations of these seem to be well chosen. In the southern UK they are at Goonhilly in the far southwest and north London. Goonhilly is probably one of the best connected places in the world. London is a majot internet exchange point.
There are many places where such speeds are not otherwise available at an affordable price.
I think you got that backwards. I know that Starlink IS supported by a network of ground stations connected to high-bandwidth fibre links for multi-200Mbit/s links in the region of each ground station.
It all depends on just how limited the uplink and downlink are. It appears that the total bandwidth of each satellite is currently about 20Gbit/s. While the ideas are easily 30 years old or more (as Globalstar had a similar architecture) the implementation is certainly impressive to me at least. Given the typical traffic levels of ordinary internet users, each satellite should comfortable support a few thousand users. After all, streaming HD video only needs a few Mbit/s. It looks a very cost effective solution for rural areas. Here is a good article about the satellite bandwidth.
It would be great to have fibre internet in all those places. It is available to around 40% of UK addresses at the moment and this is likely to double in the next five years or so. There will still be places where it is not economically viable to install fibre. There must be huge areas of the USA where it will never be viable. Why do you think that Africa offers the highest speed internet? Vast areas don't even have a reliable electricity supply. I do have some concerns about Starlink, particularly relating to the adverse effects on visible and radio astronomy and the risk of collisions with such large numbers of satellites.
John
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