Greg Moore wrote: ↑Thu Apr 09, 2020 4:28 pm
You realize every car already is equipped with a repeater. And to server as many as 160 or so devices (imagine worst case scenario, every passenger on their laptop AND their cell phone connects automatically) typical $50 repeaters won't cut it.
I'm looking at quality ones for my home and they're up in the several hundred dollar range. I suspect that's similar to what Amtrak uses.
Not all of them. The wifi signal was barely there when I did my Pittsburgh trip last year. I ended up tying to my phone 99% of the time.
I also really doubt these are just off-the-shelf consumer-grade repeaters. They're probably Cisco or Juniper repeaters, bought at bulk with a purchase order and *maybe* a contract for support.
That said, lets assume worst case: Every passenger has a laptop, a tablet, and a smart phone, and they all are streaming video. Most likely they're pulling from a major provider (Netflix, Hulu, Disney+, Youtube, etc) that auto-drops the quality down to 480p (aka DVD quality). Going through some of the movies I have in my Plex library (Godzilla 2014, Serenity, Ghost in the Shell, Guardians of the Galaxy, Ghostbusters, etc) finds a good average bitrate of 1500 kilobits/second. The California Zephyr on average has a maximum capacity of 300 passengers. So 300*3*1500 = 1350000 kilobits per second, or 1.35 gigabits/second.
802.11n (Wifi 4) is 0.054 to 0.6 gigabits per second. 802.11ac (Wifi 5) is 1 gigabit/second. 802.11ax (Wifi 6) is slated to get 1.37 gigabit/second nominal (even though it's been hyped at 4 to 11 gigabit/second). That assumes everyone's device has that level of Wifi!
Worst case is someone
has a 802.11g device (Wifi 3), the backhaul network is the same as what's being used for passengers, and now the entire freakin' network is maxing out at 0.054 gigabits/second (because of how the standard is set).
You're right, the 802.11n bearing Vocore 2 won't cut it. But then I doubt anything will given how Wifi is spec'ed out.
Not that it matters much because you can't get gigabit speed cellular currently on a good day and out in the boonies, what service? It's basically recreating a Boeing 777-8 on the track.
Thus my shift in stance. Might as well have Gogo do it for Amtrak. Technically, even I can recreate such a portal with cheap equipment, but I definitely will need to impose the no-streaming limit and offer in-cabin movies for cheap. You might as well go with a provider that already deals with that headache.