[leot]

Feel as though it's worth mentioning here that using LTE Direct (https://www.qualcomm.com/news/onq/2014/11/true-or-false-gett...) every phone could become a node in a long-range mesh network in an emergency. This approach takes advantage of both the strong radios in smartphones and the available node density provided by smartphone ubiquity.

The tech has already been proven—carriers just need to be mandated to add it because there's no business reason to do so.

[arcticbull]

> The tech has already been proven—carriers just need to be mandated to add it because there's no business reason to do so.

People say that but in the decades since it was thought up mesh networks have never actually managed to work, not at any scale. Routing efficiently is extremely complex especially when all the nodes keep moving around. I concede it may be better than nothing in an emergency but I strongly suspect it's just not very useful in general, which is probably why carriers haven't mandated it. After all if it worked you wouldn't need carriers at all, yet here they are...

[Karrot_Kream]

A route on a mesh network is only as big as the smallest link. Of course as a general substitute for connectivity it holds little promise. Like any technology it has its pluses and minuses.

In situations without access to a fat, centralized link or situations where resilience is more important than bandwidth or latency, mesh networks are a great choice. Emergencies are such situations but remote areas or low power needs are other situations suited for mesh networks.

[genewitch]

i really don't want to be this person, but Starlink is a mesh network, i have a crap connection to it, and i still routinely get over 200mbit download and 30-50mbit uploads. and a ping 1/3rd of my at&t connection (minimums around 19ms, which i haven't seen since i lived on the west coast)

> After all if it worked you wouldn't need carriers at all, yet here they are...

It'd work fine in more dense areas. Probably not the higher band 5G stuff, but lower bands and 4G. There's no carrier incentive to do this, that's why OP said "mandated".

[RF_Savage]

Does any handset anywhere actually implement LTE Direct? My understanding has been that it was specified for Public Safety LTE to have feature parity with TETRA.

Especially the infrastructure-less TETRA DMO Direct Mode Operation for ad-hoc communications with the trunking infrastructure down, out of range or over capacity.

And everybody in the Public Safety radio space seems to always laugh when LTE Direct is brought up. Apparently poorly specified and adopted by no vendors.

[ISL]

How does LTE Direct impact battery-life? Seems like something that could obliterate a handset's battery in the space of an hour or so?