People could carry future phone network nodes →
Well, see the thing is, they already do. This is not new technology by any means, but is traversing to the consumer side of the playground. Let me explain.
Law enforcement and emergency response crews have the same thing. VRS or Vehicle Repeater System is a way of extending coverage at the scene of a natural disaster or crime. Without going into too many details, it is two radios one for RX and one for TX that are programed to repeat signals on the active frequency being used by personnel. Some jurisdictions, counties and states have these repeaters, both basic and advanced, mounted onto mobile trailers, with generators and portable towers. This is really the same thing, only a lot smaller. Now that consumer grade smart phones are powerful enough to handle it, it is now a possibility, even in your pocket.
Problems with people carrying their own nodes? Yep, I can think of a few. Say, all of the nodes are out of service or coverage. Think of a family home in the boonies, all four or five nodes have no connection, so no help there, unless another node is close enough to provide service. The issue is that, cellphones only being up to one watt of output power means that these tiny nodes, must either be:
a) close to one another and/or,
b) close enough to service and close to a node that needs service.
It almost has to be a chain of nodes from service to non service areas. For example, if you lived right outside of town, with the cell tower on the opposite side of town, this networking method could help you. Also another thought that I had was that nodes COULD in fact queue messages from out of service nodes, until they were able to send them out, so for non priority items such as SMS messages, it could also work. Things that are live, such as voice calls could suffer from drops if a node moves. Nodes would be almost in constant movement, being that they are phones and not towers planted in the ground.
Really, I think it is a good idea. Its along the same lines as the femto or nano cells that cell carriers can sell. Will it catch on? No. Not yet at least. Standardizing communications protocols to work on rigid networks that carriers have could take ages.