How do cable lines on telephone poles transmit and receive data along thousands of houses and not get interference?
In: Engineering
I see a lot of discussion about multiplexing but the answers seem tangential to the original question.
For coaxial cable, interference is absolutely a concern especially from cellular bands that use the same frequencies. The cable had an outer sheath that looks like aluminum foil that provides shielding from interference. However outside energy can still sneak in from bad or unterminated connectors, among other things. This is called ingress noise.
A good cable tech will connect a test set at the curb to compare the signal at the curb to the energy coming from your house. If ingress noise is present, expect them to start replacing connectors, wallplates, etc.
Also, the cable network can tolerate a fair amount of interference using a technique called Forward Error Correction. Basically extra redundant data is transmitted, and this extra data can correct a certain amount of bit errors from interference.
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