azazel1024
Very Senior Member
I am continuing to do lots and lots of wireless testing, mostly for fun, partly to try to stamp some wifi driver bugs I have on my tablet as well as optimize my setup the best I can in my house.
Last couple of days I tracked down a "wireless bug" related to inconsistent performance. It didn't seem to have a reason as to why sometimes I'd test and I'd get 48-62MB/sec (depending on exact positioning) on my laptop for a 867Mbps 11ac transfer and then other times I'd be lucky to see 42MB/sec and maybe more like 36-38MB/sec depending on where I was sitting with my laptop in my basement. Exact same location could easily have a 10-20MB/sec variation (or 20%+).
Then last night I realized why. It wasn't run to run variation, it was test session to test session variation. The window in my basement (hopper style, so it swings in from the top when opened) was open during the tests where performance was poor and it is located only 3ft from the router (about 16 inches when opened). Close the window sitting on my couch, 50MB/sec. Open the window, 41MB/sec. Rinse and repeat.
10 minutes of playing with router location on the shelf it sits on (only viable location) and moving the router 8 inches further from the window, instead of being 6 inches from the end of the shelf) and the open vs. closed difference is 2MB/sec. 52MB/sec with the window closed (baseline performance also went up a tiny bit with the new location, at least from sitting on the couch, 20ft line of sight from the router), 48MB/sec with it open.
Much better. My tablet sees no difference now (about 9.4MB/sec average 5GHz 40MHz transfers, instead of bouncing all over from 7.5-9MB/sec with it open).
What a weird, weird thing.
To add, I also got a chance to really play with channels. Looks like the router is using the old radiation standards. Using the 147+ channels the signal strength jumps 8dBm compared to 48 and below. Line of sight performance jumps about 10% when using the higher channels. Interestingly, in a couple of quick tests with obstructions in the way (such as one floor up and a few feet over, as well as one other basement location that is 30ft away and 1 wall in the way), signal strength is only ~2dBm higher than the lower channels and performance is within 2-3% (only 1-2MB/sec faster with the higher channels, instead of ~5MB/sec faster).
Now I just have to combine that channel performance information with another test location or two (such as a far location, as all have been close/medium distance) and then try out my N600 AP with the lower 5GHz channels (currently set on the higher UNI-III band channels) to see if there is a performance impact there. Its already slower than my AC1750 router on 5GHz (obviously), so I'd rather the extra performance when I need to be connected to the N600 router than I would the, generally, small performance benefit the AC1750 router seems to have with the higher channels.
Lesson here, come on manufacturers, use the higher power limits for UNI-I!!!
PS Of course other than the anecodotal signal strengths and performance figures, I don't have a proof-in-the-pudding measurement or answer from the manufacturer that the lower 5GHz channels are using reduce power output compared to the higher 5GHz band. It does seem like it though. It could maybe be that the higher band frequencies work a lot better for EBF, or reflections off the materials in my home or something similar and nothing to do with actual higher broadcast power with the higher part of the 5GHz band.
Last couple of days I tracked down a "wireless bug" related to inconsistent performance. It didn't seem to have a reason as to why sometimes I'd test and I'd get 48-62MB/sec (depending on exact positioning) on my laptop for a 867Mbps 11ac transfer and then other times I'd be lucky to see 42MB/sec and maybe more like 36-38MB/sec depending on where I was sitting with my laptop in my basement. Exact same location could easily have a 10-20MB/sec variation (or 20%+).
Then last night I realized why. It wasn't run to run variation, it was test session to test session variation. The window in my basement (hopper style, so it swings in from the top when opened) was open during the tests where performance was poor and it is located only 3ft from the router (about 16 inches when opened). Close the window sitting on my couch, 50MB/sec. Open the window, 41MB/sec. Rinse and repeat.
10 minutes of playing with router location on the shelf it sits on (only viable location) and moving the router 8 inches further from the window, instead of being 6 inches from the end of the shelf) and the open vs. closed difference is 2MB/sec. 52MB/sec with the window closed (baseline performance also went up a tiny bit with the new location, at least from sitting on the couch, 20ft line of sight from the router), 48MB/sec with it open.
Much better. My tablet sees no difference now (about 9.4MB/sec average 5GHz 40MHz transfers, instead of bouncing all over from 7.5-9MB/sec with it open).
What a weird, weird thing.
To add, I also got a chance to really play with channels. Looks like the router is using the old radiation standards. Using the 147+ channels the signal strength jumps 8dBm compared to 48 and below. Line of sight performance jumps about 10% when using the higher channels. Interestingly, in a couple of quick tests with obstructions in the way (such as one floor up and a few feet over, as well as one other basement location that is 30ft away and 1 wall in the way), signal strength is only ~2dBm higher than the lower channels and performance is within 2-3% (only 1-2MB/sec faster with the higher channels, instead of ~5MB/sec faster).
Now I just have to combine that channel performance information with another test location or two (such as a far location, as all have been close/medium distance) and then try out my N600 AP with the lower 5GHz channels (currently set on the higher UNI-III band channels) to see if there is a performance impact there. Its already slower than my AC1750 router on 5GHz (obviously), so I'd rather the extra performance when I need to be connected to the N600 router than I would the, generally, small performance benefit the AC1750 router seems to have with the higher channels.
Lesson here, come on manufacturers, use the higher power limits for UNI-I!!!
PS Of course other than the anecodotal signal strengths and performance figures, I don't have a proof-in-the-pudding measurement or answer from the manufacturer that the lower 5GHz channels are using reduce power output compared to the higher 5GHz band. It does seem like it though. It could maybe be that the higher band frequencies work a lot better for EBF, or reflections off the materials in my home or something similar and nothing to do with actual higher broadcast power with the higher part of the 5GHz band.