The invention includes a telephone using the PSTN, a control module, an ADSL module, and an access and display unit. Using the above, conventional telephone lines are employed for providing a video telephone capable of bi-directional video and audio transmissions. The video telephone is connected with...http://www.google.com/patents/US6924831?utm_source=gb-gplus-sharePatent US6924831 - Video telephone integrating public-switch telephone network and asymmetric digital subscriber line
