OK, I've just set up me new SIM router with a DTAC annual SIM described as 15Mbps. The GoMo one didn't pan out. It's successfully connected to my phone, laptop and TV stick. All seems good and running normally.
However, when I run testmy.net it gives results around 4Mbps download. This is from my laptop and is not much different using a LAN cable or using wifi. Phone is similar speed on wifi. DTAC signal is strong according to the router status screen.
I understand the location of the router can be important so will try it in a couple of different places, but apart from that should I be getting a higher speed and how do I go about it?