| 摘要 |
<p>Telephone service subscribers who are connected to a telephone network via local loop lines to local telephone switches are also connected to a data network without communication through the local telephone switches. The system has frequency translator devices for translating send and receive voiceband frequency signals used by voiceband data modems to different frequency bands above the voiceband used by the telephone network. The voiceband modems at the subscriber premises maintain a connection in the presence of transient signals caused by on-hook and off-hook activity of voiceband subscriber equipment. The system also has data network bridge equipment connected between the local loop lines and the data network for bidirectionally converting the translated voiceband frequency modem signals into digital data signals and bidirectionally relaying the digital data signals to the data network. Internet access is made possible using conventional voiceband modems at the subscriber premises and using out-of-band transmission over the local loop lines so as to provide the Internet access without loading the local telephone switches and without preventing use of voice telephone service at a same time as Internet access is in progress.</p> |
