3 ms·

>The lower speed on 4G is mostly due to the number of devices on it. Is that the sole reason 5G is faster, or will being able to allocate less in idle situatio

>The lower speed on 4G is mostly due to the number of devices on it. Is that the sole reason 5G is faster, or will being able to allocate less in idle situations and utilize spatial multiplexing support faster speeds even with a comparable number of devices?

taeric 9y ago
Allocating less in idle situations sounds dangerous. What do you do when there is a real world event and everyone rushes to their device, pulling them out of idle? (I'm assuming this problem is already considered. Genuinely asking, in case someone has a good link to read on it.)
- jdietrich 9y ago
  It's straightforward QoS management. Public service users get absolute priority, even if that means kicking everyone else off the network. After that, voice and SMS get priority, because they're important to users and have very low data rates. IP traffic can have whatever's left on a fair queuing basis. Most operators use deep packet inspection and can perform fairly sophisticated traffic shaping.
  - taeric 9y ago
    That makes some sense. But "kicking people off" is a crappy answer. Especially since you are setting up a constant storm of users trying to reconnect. Easy to see how that will not play well with idle connections.
    - jdietrich 9y ago
      >Especially since you are setting up a constant storm of users trying to reconnect. The network isn't that dumb. The technical details are far beyond the scope of a HN comment, but the network can gracefully deny service to users. Think about what happens if you run out of data allowance or prepaid credit - your phone doesn't frantically spam the network, it just asks for service and is politely told to try again later. If all else fails, you can just de-register all the devices connected to a given cell site and revert them to emergency calls only.
      - taeric 9y ago
        Right, that was why I was asking if someone had a good link to read on. :) And, honestly, from the way I've seen phones behave on older wifi networks, I would be surprised if some aren't actually spamming the network. Unnecessarily fast. Worse, I would hope the network has some protection built in for the bad actors that do.
        Rjevski 9y ago
        > the network has some protection built in for the bad actors that do. They don't. It's extremely easy to DoS an off-the-shelf (Ericsson, etc) mobile network if you know what to do. All it takes is one packet per minute or so. ;)

taeric 9y ago

Allocating less in idle situations sounds dangerous. What do you do when there is a real world event and everyone rushes to their device, pulling them out of idle? (I'm assuming this problem is already considered. Genuinely asking, in case someone has a good link to read on it.)

jdietrich 9y ago
It's straightforward QoS management. Public service users get absolute priority, even if that means kicking everyone else off the network. After that, voice and SMS get priority, because they're important to users and have very low data rates. IP traffic can have whatever's left on a fair queuing basis. Most operators use deep packet inspection and can perform fairly sophisticated traffic shaping.
- taeric 9y ago
  That makes some sense. But "kicking people off" is a crappy answer. Especially since you are setting up a constant storm of users trying to reconnect. Easy to see how that will not play well with idle connections.
  - jdietrich 9y ago
    >Especially since you are setting up a constant storm of users trying to reconnect. The network isn't that dumb. The technical details are far beyond the scope of a HN comment, but the network can gracefully deny service to users. Think about what happens if you run out of data allowance or prepaid credit - your phone doesn't frantically spam the network, it just asks for service and is politely told to try again later. If all else fails, you can just de-register all the devices connected to a given cell site and revert them to emergency calls only.
    - taeric 9y ago
      Right, that was why I was asking if someone had a good link to read on. :) And, honestly, from the way I've seen phones behave on older wifi networks, I would be surprised if some aren't actually spamming the network. Unnecessarily fast. Worse, I would hope the network has some protection built in for the bad actors that do.
      - Rjevski 9y ago
        > the network has some protection built in for the bad actors that do. They don't. It's extremely easy to DoS an off-the-shelf (Ericsson, etc) mobile network if you know what to do. All it takes is one packet per minute or so. ;)