Weekend Speed Problems

[#1]

Hi,
We seem to be expereiencing problems with speed particularly at weekends. This is what BY wholesale speed test says:
1. Best Effort Test:  -provides background information.
Download  Speed
10.42 Mbps
 
0 Mbps 21 Mbps
Max Achievable Speed
Download speedachieved during the test was - 10.42 Mbps
For your connection, the acceptable range of speeds is 4 Mbps-21 Mbps.
IP Profile for your line is - 10.65 Mbps
2. Upstream Test:  -provides background information.
Upload Speed
0.04 Mbps    
0 Mbps 0.83 Mbps
Max Achievable Speed
Upload speed achieved during the test was - 0.04Mbps
Additional Information:
Upstream Rate IP profile on your line is - 0.83 Mbps
I am very worried to see the upload speed is 0.04!
How can we go about starting to get this looked at?
Regards,
Doug

[#2]

Are you using a wired or wireless connection to the router?

[#3]

On this occasion I was using a wireless connection.

[#4]

You need to test the speed wired. It could be that a neighbour is also using a wireless connection on the same channel as you when you experience issues. If you prove it is just the wireless slowing down at certain times, manually selecting a different channel would likely improve things.