Should be a Signal to Noise Ratio (SNR)
You are looking for the largest number possible from your setup. Try right next to your AP and move until you find the place you want.
Don't forget if your AP has an adjustable antenna, you can tilt them and angle the signal towards the area you want to have the laptop in.
Though under appreciated, the usb adapter can be coupled with a few household parabolic dishlike items for a big signal gain.
Of course you will get the raised eyebrows from this.