11g / Super-G overlap
Figure 6 shows another spectrum analyzer composite shot supplied by Atheros.
Figure 6: Super-G and normal 11g signal overlap (from Atheros)
This time, it shows normal 11g signals on channels 1 and 11 and a Super-G "static turbo" signal centered on channel 6 from a WLAN approximately 35 feet away from the normal 11g devices. The amount of overlap between the normal 11g and Super-G signals would have more clearly illustrated if all had been plotted at the same distance so that all peak signal levels were equal, but this is what Atheros supplied.
Figure 7: Super-G and normal 11g signal overlap (from Broadcom)
Broadcom's shot in Figure 7, though, shows a full-strength Super-G signal overlapping into drawn-in markings for channels 1 and 11 so that you're sure to see that the Super-G signal is pretty much at full strength when it first overlaps into both "non-overlapping" channels.
A few notes about Super-G:
- Super-G has dynamic (auto) and static modes. Static mode is intended to be used in all Super-G WLANs and kicks in all of Super-G's features, including channel bonding.
- Super-G mode is centered on channel 6 and can't be moved.
- Dynamic mode is intended to be used in mixed WLANs and takes into account the types of stations (clients) in the WLAN and their bandwidth demands.
- The Super-G signal shown in Figures 6 and 7 is what you'd see in static mode or dynamic mode under maximum bandwidth demand conditions.
So now we've established a second key point:
Key Point #2: Under similar range and bandwidth demand conditions, Super-G signals can have a greater degree of overlap into channel 1 and 11 than a normal 11g channel 6 signal.
With those points in mind, it's now time to put them to the test.