What technology to choose for local positioning with an accuracy of 1 m (distance up to 100 m) and data exchange (video, speech)?

Question

satellite navigation

The question is the choice of technology, at first I chose positioning using GPS and refinement using Zigbee. Data transmission via Wi-fi, namely voice and sound. I have doubts about my decision, and want to see people's opinions on the use for this task. For subscribers, I chose raspberry pi 2 B, insert wifi and zigbee via usb into it, and bluetooth to communicate with the heart rate monitor. the strongholds will be equipped with a zigbee modem. on the zu there will be a laptop and the wifi access point is external, it should be suitable here according to the characteristics. Raspbperry has already bought, about the rest of the questions. I think maybe it's better all the same for transmitting GSM information. and nothing is known about building a UWB network, maybe this is the best solution? Are there any experts in this field who can help with the task?
The task itself is this: the system consists of a control center and auxiliary points, which serves 20 subscribers. Service area 70m is better than 100m. Subscribers performing special work (firefighters, riot police, etc. may be rescuers or climbers), i.e. the conditions are unpredictable and the system must be wireless. Subscribers must talk to each other and tsu and transmit video to the control center. Through auxiliary points, the m / n is determined and transmitted to the control center. Other devices of subscribers, in addition to the camera and audio, must be equipped with a heart rate monitor.

Answer 1

local positioning, if not from gov ^ W acorns and plasticine, these are solutions like Ekahau
> Subscribers ... firefighters, riot police, etc.
> For subscribers, I chose raspberry pi 2
Fire danger!! 1
You can’t choose consumer electronics for such work, otherwise it will be like in a file with a black box from an airplane flying over the Turkish border.

Answer 2

firefighters, riot police, etc.

And how are you going to certify your crap for special forces?
There are sensors and tablets for firefighters - we are talking about people's lives, everything is very serious and expensive.
There is also for the military .

Answer 3

There are ground stations for GPS correction, though I have no idea how mobile they are and how much they cost. https://ru.wikipedia.org/wiki/%D0%A1%D0%B8%D1%81%D...
But if it works out, then almost any smartphone can act as a subscriber device.