There are 2 roles of router in the camper:
No all routers with owned firmware can provide functions as need for the Camper assistant, others can. Anyway the OpenWrt OS can be installed on the router in most cases. Here described customization of the Netgear R6220 with OpenWrt OS installed. This one model is not the best choice for the Camper assistant's functions realization because of modest power of Wi-Fi radio. But this case described as "general case". In next articles will be described the making and mounting of antennas for this case at the camper. With some other routers (as a rule - outdoor Wi-Fi routers), the making additional antennas may be not needed.
All settings were made via Windows PC. In some cases will need switch off the PC firewall while settings. The Netgear R6220 router was attached to the PC via RJ-45 patch cord while settings.
OpenWRT was logged in on IP 192.168.1.1 with login root and password 1234.
The "Hostname" was set to CA-RTR (mean Camper Assistant Router) in System.System menu, and was click on to "Sync with browser" next to "Local Time".
With this name this router will broadcast in the Camper's network.
At this moment was switched on Wi-Fi access point name "CA-WFE" as described in article about Internet Wi-Fi extender. But it can be any other method of Wi-Fi hotspot deployment used, for example on a mobile device.
In Network.Wireless menu was pressed "Scan" next to "radio0".
In text tab was "Join Network" next to "CA-WFE".
In next tab was changed: "WPA passphrase" to CA-WFE password, "Name of the new network" to "wwan" (can be any other name), "Create / Assign firewall-zone" to "LAN", then was clicked "Submit".
In next tab was changed "Operating frequency Channel" to "11", "Operating frequency Width" to "40", "BSSID" to blanked, "Netwrork" to "wwan" (was setted on previous step) and to "lan", then was clicked "Save & Apply".
Setting the Wi-Fi channel to 11 permanently in this case allows the radio0 to be switched on for all time while the router is need for the Camper assistant's purposes. This is the channel of the acces point of the EDUP EP-AC1621 USB Wi-Fi adapter used for the Internet Wi-Fi extender. Most of USB Wi-Fi adapters broadcasts on the 11 channel of 2.4 band.
Then in Network.Wireless menu was pressed "Edit" next to "SSID: OpenWrt" in "radio0" section.
In next tab was changed "ESSID" to "CA-APR" (mean Access Point & Router 2.4 band), "Netwrork" to "lan", "Wireless Security Encryption" to "WPA2-PSK", and was entered Wi-Fi password in "Wireless Security Key" field, then was clicked "Save & Apply".
In menu Network.Firewall was clicked "Add".
In next tab was changed "Name" to "brgzone" (can be any), "Forward" to "accept", "Masquerading" to On, "MSS clamping" to On, "Covered networks" to "lan" and to "wwan", then was clicked "Save & Apply".
In menu Network.Diagnostics was pressed "Ping" for the checking of Internet connection.
Note: one of the latest version of OpenWrt OS can used for router Netgear R6220 where function of "bridging" between interfaces is built in. But if will be used some router which can only launch an old versions of OpenWrt OS, the "bridging" function must be especially deployed, for example as described in article Video recorder and streamer (wireless IP camera).
Then in Network.Interfaces menu was pressed "Edit" next to "LAN" box.
In opened tab was changed "IPv4 address" to "192.168.8.1", "IPv4 netmask" to "255.255.255.0", then was clicked "Save & Apply".
Optional may be helpful to add custom DNS servers in this form:
In opened tab (need time to wait) was clicked "Apply unchecked".
From this point, the router can be accessed on IP 192.168.8.1 in the Camper's network. Any LAN devices can be switched to RJ-45 ports of the router, any Wi-Fi devices can be connected to Camper's AP named "CA-APR" on 2.4 band. All of them can take Internet if Internet Wi-Fi extender or any other mobile device distributes Internet via access point named "CA-WFE" at this time.
Then, after new login in OpenWrt had, in Network.Wireless menu was pressed "Edit" next to "SSID: OpenWrt" in "radio1" section.
In next tab was changed "Mode" to "AC", "Channel" to "48", "Width" to "80 MHz", "ESSID" to "CA-APR5" (mean Access Point & Router 5.x band), "Netwrork" to "lan", "Wireless Security Encryption" to "WPA2-PSK", and was entered Wi-Fi password in "Wireless Security Key" field, then was clicked "Save & Apply".
The router was disconnected to the PC.
From this point, any Wi-Fi devices can be connected to Camper's AP named "CA-APR5" on 5.x band. But need keep in mind that this band for "Indoor" use often required by regulatory rules, and that 5.x band works on short distances. Good idea to use connection on 5.x band only within a camper.
Being tuned as here described and based on OpenWrt properties, the access point "CA-APR5" (i.e. on 5.x band) can work all time, but access point "CA-APR" (i.e. on 2.4 band) can work only if "CA-WFE" broadcasts (no matter distribute Internet in this time or not). If "CA-WFE" distributes Internet, the global net will on both bands.
Summarizing this notes about tuned Wi-Fi bands, preferably the use AP "CA-APR5" for interconnections within a camper while AP "CA-APR" for Internet surfing and connection to camper's equipment for long distances.
Attention! There are many routers with Wi-Fi radio on a market. When buying a router in one country from an official dealer, no questions about the use may arise. But while traveling with this router to different countries, need to comply with the regulatory rules of these countries for the use of Wi-Fi. This rules can very differ.
For any Wi-Fi radio, no matter client this or master broadcasts, need to set "Country code" according to current location (in Network.Wireless menu in section "Advanced settings").
OpenWrt being tuned as here described, provide acces for this function in the camper's network anytime on IP 192.168.8.1.
In the following articles will be described how to switch "Country code" automatically based GPS parameters.
With used router Netgear R6220 (and most others), If more then four camper assistant's devices will be wired in network, then a switch required. This switch need only attach to LAN port of the router.