A dual-mode filter network for an Asymmetric Digital Subscriber Line (ADSL) has a first frequency response when the Plain Old Telephone Service (POTS) telephone is on-hook and has a second frequency response when the POTS telephone is off-hook. A detector is used to determine the on-hook/off-hook status....http://www.google.fr/patents/US6137880?utm_source=gb-gplus-shareBrevet US6137880 - Passive splitter filter for digital subscriber line voice communication for complex impedance terminations
Passive splitter filter for digital subscriber line voice communication for ...
