Put it in a different location in the house. Near a window on the correct side of the house (what is "correct" you find by experiment!). I think you can get an external aerial fitted too.
Are you still experiencing an issue with the signal strength? Or did moving the device around as suggested by @Psmithson resolve this?
If not, I'd recommend checking out our Network Status Checker as this will shed light on any reported issues or work being carried out that could be impacting you.
