4 ms·

And you haven't even mentioned the fact that mobile phones can move around, leading to high rates of dropped connections as devices come and go. There's no way

by angott 8y ago

And you haven't even mentioned the fact that mobile phones can move around, leading to high rates of dropped connections as devices come and go. There's no way this is going to work.

remyM 8y ago
Whoops, my phone connected to someone on a train that just went past! My phone call just dropped.
- sliken 8y ago
  Think of it the opposite way. You have no coverage, are trying to get a message out and the nearest gateway is miles away. A moving car/train is close to you for plenty of time to transfer a few 100 bytes, and someone in the car/train has a mesh aware widget. It stores a copy and waits to go near a gateway where it upload it for you. Sure, it's not as nice as a WAN connection, but the average cellular contract is pretty expensive per month. Something like $10 per GB, and often a $30 and up base rate. So sure, long distance multi-hop mesh stinks for real time voice, but could be quite usable for other use cases.
  - mirashii 8y ago
    Ah, but now you're talking about solving an additional problem, delay tolerant networking, on top of mesh networking. This adds a whole new layer of complexity on top of the mesh network, and would probably only work as you say for a subset of services that are made to handle this type of unreliable network. Also many common delay tolerant network implementations rely on message replication to increase the probability of delivery of the message. This puts additional bandwidth strain on the inter-node hops of the network, which as some of the other commenters pointed out, not actually all that high.
    - sliken 8y ago
      Indeed, seems only practical for things like SMS/IM type traffic where even a Long/LAT + 30 character message every few minutes would be quite useful.
- a3_nm 8y ago
  Why would your call be routed just via one single phone?
  - rocqua 8y ago
    Are you going to send the message over more than one route? That doubles the required bandwidth over the entire mesh.
    - awelkie 8y ago
      You could do something smarter with error correcting codes. Using a rateless code you split your message into an infinite number of chunks, then send these chunks out on your multiple paths, and then once enough chunks have been received you ACK each path. No bandwidth wasted. I think specifically with voice it should be possible to send two chunks such that if they both arrive then you get your audio, and if only one arrives then you still get your audio but at a lower quality.
    - angott 8y ago
      This is similar to Multipath TCP, for anybody interested: https://en.wikipedia.org/wiki/Multipath_TCP https://en.wikipedia.org/wiki/Multipath_TCP
cbsmith 8y ago
Cellular phone deal with this when you are in motion anyway. You just need redundant routes to offset the volatility of the network. A half mile per hop range could work, if the network is sufficiently dense (and the number of egress points is sufficiently high). This is the kind of thing you do a test with in a specific targeted community though...

by angott 8y ago

And you haven't even mentioned the fact that mobile phones can move around, leading to high rates of dropped connections as devices come and go. There's no way this is going to work.

remyM 8y ago

Whoops, my phone connected to someone on a train that just went past! My phone call just dropped.

sliken 8y ago
Think of it the opposite way. You have no coverage, are trying to get a message out and the nearest gateway is miles away. A moving car/train is close to you for plenty of time to transfer a few 100 bytes, and someone in the car/train has a mesh aware widget. It stores a copy and waits to go near a gateway where it upload it for you. Sure, it's not as nice as a WAN connection, but the average cellular contract is pretty expensive per month. Something like $10 per GB, and often a $30 and up base rate. So sure, long distance multi-hop mesh stinks for real time voice, but could be quite usable for other use cases.
- mirashii 8y ago
  Ah, but now you're talking about solving an additional problem, delay tolerant networking, on top of mesh networking. This adds a whole new layer of complexity on top of the mesh network, and would probably only work as you say for a subset of services that are made to handle this type of unreliable network. Also many common delay tolerant network implementations rely on message replication to increase the probability of delivery of the message. This puts additional bandwidth strain on the inter-node hops of the network, which as some of the other commenters pointed out, not actually all that high.
  - sliken 8y ago
    Indeed, seems only practical for things like SMS/IM type traffic where even a Long/LAT + 30 character message every few minutes would be quite useful.
a3_nm 8y ago
Why would your call be routed just via one single phone?
- rocqua 8y ago
  Are you going to send the message over more than one route? That doubles the required bandwidth over the entire mesh.
  - awelkie 8y ago
    You could do something smarter with error correcting codes. Using a rateless code you split your message into an infinite number of chunks, then send these chunks out on your multiple paths, and then once enough chunks have been received you ACK each path. No bandwidth wasted. I think specifically with voice it should be possible to send two chunks such that if they both arrive then you get your audio, and if only one arrives then you still get your audio but at a lower quality.
  - angott 8y ago
    This is similar to Multipath TCP, for anybody interested: https://en.wikipedia.org/wiki/Multipath_TCP https://en.wikipedia.org/wiki/Multipath_TCP

cbsmith 8y ago

Cellular phone deal with this when you are in motion anyway. You just need redundant routes to offset the volatility of the network. A half mile per hop range could work, if the network is sufficiently dense (and the number of egress points is sufficiently high). This is the kind of thing you do a test with in a specific targeted community though...