It's probably switching cell towers.Hi guys, new to this forum and it's brilliant, some great info.
I've the same issues as most on here with the B535 router on 3 mobile us. I was on a BT landline giving ~ 1Mb DL and 0.3Mb UL. The issue I keep having is that my B535 is working perfectly on the green light with 5 bars of signal giving ~ 10Mb DL and 6Mb UL then it changes to the blue light on 1 Bar of signal and the UL and DL drop through the floor. Anyone know how to resolve this or limit it from going into the better blue bars?
Try pointing the router at the nearest tower, or use the carboard & tinfoil around the back of the router hack to see if you can lock it to the best tower, if so then getting a directional antenna might help.