A site on a local network on a server and the Internet, where there is no network?

Question

linux

Hello!
The question is such a new task was received:
Multimedia in a suburban bus, an idea.
There is a wi-fi user is authorized from the device. Gets to the site that is installed on the server, which is located in the bus.
On the site you can choose a movie that you want to watch (which is uploaded to the server)
Read news, and other interesting things.
Question 1.: what power should the server have in order for the site to spin on it and so that 20 people can watch streaming
video at the same time (how much power is needed when you never thought about it)
weighs 500 MB each
Any options? Link to the model.
When the bus is moving, is there any interruptions in the Wi-Fi?? (in my understanding it should not be)
Regarding the Internet, how can you get it if there is no network on the highway, it works on planes (satellite?)
How much does it cost and traffic.
The new interesting task is planned 150 such buses.
They are ready to pay for a competent explanation, they are also ready to cooperate with people who have implemented this, the main thing is not on their knees, but using modern solutions.

Answer 1

Let's guess.
If we take an average stream of 1 Mbit / s, we get 1 movie (2 hours) that will take up to 1 GB, which is enough with a margin, the h264 480p codec with such a bit rate will look good on mobile devices.
A dual-band 2.4\5GHz n\AC standard access point will give 20-30 users at 1Mbps in 2.4 mode and 50 or more at 5GHz. Even if we estimate that the majority have old devices, then we will definitely meet 20. Total stream up to 50Mbps.
You can take rpi 3 and try to run on it, but most likely its performance will not be enough for 5-10 clients already. I advise you to immediately look at something like the Intel NUC or its analogues, it will definitely be enough with a margin.
You can probably even raise the bitrate to 2Mbps and video resolution to 720p.
Articleabout how to make streaming on nginx.

Answer 2

Instead of difficulties with wifi and the hope that users will have normal devices sufficient for viewing, plus the hope that all users will be able to connect on their own, plus the fact that this is a local network and not every adequate user will be ready to connect his device to an incomprehensible network -
better budget tablets with seat back mounts and stock travel media.
We need a specific solution in the form of anti-vandal cases or, in general, a special order for tablets with a ready-made case, with closed home buttons, so that only the user interface is available.
Pros -
*No connection required at all. A sufficient number of films fit almost any tablet.
* No need for a server at all and its maintenance/location/setting up networks/possible hacking of the server by bored scriptkiddies.
* In the event of a breakdown, simply reboot the device. In case of a serious breakdown, any driver simply opens the anti-vandal housing with his key and replaces the device with a spare one in 2 minutes (1-2 spare ones are enough for a flight). If there are free places, the stock of spare devices grows similarly.
* No streaming video - each passenger can choose what he wants to watch. Children are cartoons, adults are porn action movies. You can add free or cheap disposable video headphones to your flight.
* By agreement with cinemas, you can play all sorts of teasers, etc.
* Viewer software can intelligently show the right ads, earning you money.
* In addition to movies / cartoons, you can also add simple toys / audio books / etc. or just interesting articles (from habr)

Answer 3

Let's start with simple technical requirements.
Data storage. In the modern world, a film of average quality at least in 720p takes 1 GB/Hr. Those. 2 GB per movie. 50 movies = 100 GB hard drive.
I recommend staying with a 256 GB SSD. An SSD is necessary for 2 reasons - working on a bus involves a significant amount of vibration, which will lead to the failure of ordinary hard drives, in addition, multi-threaded streaming requires access to 20 different files at the same time at a fairly significant rate, which a regular one cannot give you HDD.
As for the rest of the computer - it's best to take some mini-computer without a fan, like this. Without a fan, it is very important because you are tired of cleaning dust and changing fans. To the computer, a converter-stabilizer from the on-board network of the bus is required. You can look for these on AliExpress, but it's better to find electronics / radio amateurs, they will do everything right.
Regarding the network, it turns out from 2.5 MBit / s per client. Plus, to support authorization and the page, you will need a captive portal . For stable distribution at such a speed for such a number of clients, ordinary home access points are not suitable, corporate-level access points are needed. I advise you to look at dual-band points from Ubiquiti or Microtik. The task of the access point is simply to redirect the person to the server.
In terms of software for the server, definitely Linux, nginx + hls + mp4streaming. The video must be converted to mp4 with optimization for the web. For the server, you will need to write a small script that will bypass the movie directories and generate an index plus a small page for each file.
Since the PCs themselves also have wi-fi, they can be configured to connect to your home "bus-to-bus network". Its meaning lies in a simple thing. syncthing is installed on each computer, which will synchronize videos between computers. Those. it will be enough to put the video on one computer and all the others will be synchronized with each other. Not very fast, but easy to maintain.
If you really want modern solutions, then look here https://mobileonboard.com/beam-bus-wifi-systems/ and herehttps://www.quora.com/What-is-the-best-system-for-...
But the topic is such that you need a specialized hardware and software system. Alas, it will cost more than the bus. Just in a good way, you need to take a computer and an access point, assemble power adapters for them, put everything in a normal case that is resistant to vibrations and temperature extremes. Yes, and attach to it all the software. Despite the external simplicity, this is a complex technical solution.

Answer 4

Also the budget stove?
There are many options for connecting to the network: a satellite, a lot of mocks from different operators, your own radio towers, caching from roadside objects + you can look at various Internet protocols for cars. The cost also depends on many factors, such as the route.
There should be no interruptions in the work of Wi-Fi. Bandwidth depends on video quality: from 20 Mb/s to 1 Gb/s. Well, the power of the server is corresponding.