PPC iMac G5 / mac OS X 10.4.11 Tiger / Internet Issues

You are rolling the dice as to whether that ASUS WiFi adapter will be compatible with the ancient USB ports on that PPC Mac, or that the ASUS adapter comes with mandatory drivers that are not compatible with a PPC architecture.

Even if you can get the IP connectivity issues sorted out, https security protocol’s have changed since Mac OS X Tiger days.

You are unlikely to be able to connect to most modern https Web sites.

Regarding the wireless connection per se: As you already know, a USB Wi-Fi adapter connected to a USB port of the G5 would require a special driver. Not many Wi-Fi adapters support old Mac OS X systems, but an older version of Edimax EW-7811Un (plain, not V2) once appeared to have a 10.4 driver.

In order to avoid the driver problem a better way may be to connect a wireless Ethernet bridge (such as Linksys WET610N) to the Ethernet port of an old Mac computer. A more modern variant of this could be to use a Wi-Fi range extender (perhaps something similar to TP-Link RE200 or Edimax EW-7438RPn Mini) with an Ethernet port and Ethernet bridge capabilities (operating in a Wi-Fi adapter/client mode). This solution does not normally require special software/drivers. The setup can usually be carried out via a web browser (if necessary, on a newer computer). Modern security standards are typically supported.

The second problem is that browsers compatible with Mac OS X 10.4 Tiger are not capable of handling modern (secure, https) web pages, as Servant of Cats pointed out. You can really only expect the few remaining http sites to work (one example would be knubbelmac.de).

It sounds like there might be a compatibility issue with the internet sharing setup between the Mac Pro, PPC iMac G5, and the Android phone. You could try using a wired USB Ethernet adapter for more stable connection on the PPC iMac G5.

Just one question, why would you need a USB-to-Ethernet adapter? The iMac G5 has built-in Ethernet.