Cannot get an IP

I have a problem at the end of a quite simple Wifi network. Maybe someone could switch on a light for me?


This is my setup:

In town we have a TPLINK TL-WA5210G device connected via ethernet to a
DSL broadband router with DHCP server enabled.

4 km away, on top of a radio tower there is another TL-WA5210G
linking to the first one. Link is fast and stable (2.4 GHz) as there is a line of sight.

The first TPLINK is set to point to point (bridge mode) to the second one up the tower in point to multipoint.

From this last one we run down the tower a LAN cable for PoE supply and
connection to a one radio router. It gives WiFi and LAN connectivity to the
site flawless.

There is another house, at about 150 metres away, that we want to
provide also internet coverage. We have now another one radio router, a Belkin Wifi AP/router in bridge mode that links to the tower TPlink device. The Belkin thing works fairly good but it needs to be placed outside a window to have a good view to the tower's TPLINK. So I got an ARC Splitstation, an Outdoor / Indoor Dual Radio Set. After many tries I've got Internet on PC connected directly to the ARC router on LAN but via radio it was very difficult to get an IP, mostly it timed out getting the 169.x.x.x IP.

Got in contact to ARC Wireless Solution but they couldn't find a solution. So got another dual radio device.

It's the Airlive G-DUO with a 18 dBi external antenna for RADIO1 (ch 13).
RADIO2 is on ch 1.

I have tried WISP+AP, GATEWAY+AP, AP-AP, Client+AP modes. In any case
I cannot get the Airwell to provide a valid IP address in the segment
of the DSL router. Believe me, I have tried almost everything and
spent many hours digging on this.

With this device I'm just unable to get the LAN or Wifi to provide an
IP address from the main dsl router through the Wifi link. Keys and
channels are ok. Co-chanel interference is avoided.
I can see on Airlive status tha radio from TPLINK is connected. And on
the TPlink side the Airlive RADIO1 is associated properly and with
connected status. MAC address of the Airlive RADIO1 is set on the
TPLINK side correctly.

I have also a Linksys router with DD-WRT firmware and it works OK. But
it also has only one radio.

Perhaps what I'm trying to do is not possible.

Please kindly give me advise of anything that I could try.

Regards
JR