Can I use 1 wireless card for both LAN (AP) and WAN (Infrastructure)?

[jptech]

Hi,

I'm wondering what kind of limitations I should expect, if any, when using aliased wireless devices.  My goal is a dual WAN config where the 2nd WAN can connect to the hotspot of a cell phone to provide a small amount of fail over to a wireless network, but without the added cost that comes along with a 3G/4G module and dedicated wireless service.

I've made 2 attempts so far.  The first using an ALIX 2D13 and a Wistron DNMA-92 (Atheros AR9220) wireless card.  For the second attempt I used an ALIX APU1C4 and a WLE200NX (Atheros AR9280) wireless card.  In both cases I can get the configuration set up like I want.  This uses two WLAN devices; the main (parent) device and an aliased device.  I use the main one in AP mode bridged to the LAN.  I use the aliased one in Infrastructure mode and connect it to the AP on my phone.

In both cases, I can't get the wireless interfaces to stay up consistently enough to make it usable.  I have more wireless hardware I can test, but wanted to make sure I'm not trying to do the impossible by using only 1 wireless card.  Should it be possible to do what I want?