SNR is one of the most significant factor in determining the quality and therefore speed of your broadband internet connection. As we have already seen, ( refer http://hubpages.com/hub/DataOneSignificanceofSNRandAttenuation ) SNR is nothing but the ratio of signal to noise. Higher the SNR, higher will be the quality of service. As a customer can't do anything eith the transmitted signal power, to improve SNR only thing we can do is to minimise the noise part.

Source of Noise :

Noise can be anything other than the intended signal. Various signal sources that may affect ADSL broadband spectrum are

1) Other electronic appliances like fluorescent tubes with electronic choke which may interfere ADSL band

2) Noise due to imperfect joints in the line.

3) Poor quality of wiring cables.

4) Poor earthing in the house

Remedies :

All of the above mentioned sources of noise can be minimised by taking proper care. In most cases, the problem may be due to unwanted joints in the line or improper earthing. Making a perfect earth will help reduce noise in a better manner. To check earth linkage, emasure the neutral -> earth voltage in the supply line. For a good earth the measured value should be below 2V ( theorotically 0V).

Look for any improper joints ocuring in the connection line, as joints are the most important sources of noise.

Be sure to minimise the length of the connection line, since the length determines the resistance of the line.