Personal Area WiFI networks

The first step to getting my devices working for me is to set up a consistent network for them to use. To do this I am going to use a small pocket sized router that can be run from a usb battery to act as a hot spot for my devices, but also as a bridge to an internet connected wifi network.

The network I want to setup looks something like this:

                                                   +
  +---------+                                      |
  |  phone  <<-------+                             |
  +---------+        |                             |
                     |                             |
  +---------+        |  DHCP     PANWIFI           | DHCP    PUBLIC WIFI
  |  laptop <<-------+      +-----------------+    |    +-----------------+
  +---------+        |      |                 |    |    |                 |
                     +---->>>   OpenWRT       <<<----->>>                 +---->  INTERNET
  +---------+        |      |                 |    |    |                 |
  |  camera <<-------+      +-----------------+    |    +-----------------+
  +---------+        |             192.168.x.x/xx  |
                     |10.10.10.0/24                |
  +---------+        |                             |
  |  pda    <<-------+                             |
  +---------+                                      |
                                                   |
        Personal area wifi network                 |  Upstream wifi network
+--------------------------------------------------+---------------------------------------+

I struggled to find a network configuration like this in the OpenWRT wiki. I wondered for a while if it was because the network was an impossible (seemed unlikely) or if it was so obvious to not be worth documenting.

Eventually google turned up a bitbucket page with a config that worked perfectly.

I need to find a method which makes it straight forward to configure a new outgoing network. I think at the moment I am going to have to edit the wifi config files to make any changes. On the road that will be less than ideal.