US 6,587,473 B2 · Information network access apparatus and methods for communicating information packets via telephone lines

Abstract

Access to a CSMA/CD (Carrier Sense Multiple Access with Collision Detection) network is provided via a telephone line by providing a master modem at the head end and a slave modem at the subscriber end of the line. The master modem provides a CSMA/CD interface to the network and controls half duplex communications with the slave modem via the line to avoid collisions of information packets on the line. The information packets are enveloped in frames on the line with error checking information; control information between the modems is contained in the same and/or in separate frames. The modulation method and signal bandwidth can be varied depending on errors to provide optimum communications capacity via any particular line, and a ratio of upstream to downstream information packets can be varied depending on buffer fills at the modems. The master modem can be multiplexed for multiple lines. The modulated signal frequencies are above telephone signal frequencies so that each line can be frequency diplexed for simultaneous telephone communications.

Claims42

Dependent claims

A method of communicating information packets to and from a CSMA/CD (Carrier Sense multiple Access with Collision Detection) path via communication of information corresponding to the information packets over a bidirectional communications path, the method comprising the steps of:

coupling a first end of the bidirectional communications path to the CSMA/CD path via a first modem having a CSMA/CD interface coupled to the CSMA/CD path, wherein the first modem is coupled to the first end of the bidirectional communications path via a first end interface;
communicating the information packets between the CSMA/CD path and the first modem via a CSMA/CD interface;
coupling a second end of the bidirectional communications path to a second modem, wherein the second modem is coupled to the second end of the bidirectional communications path via a second end interface;
communicating information corresponding to the information packets between the first and second modems via the bidirectional communications path using half duplex communications controlled by the first modem, wherein each of the information packets comprises a MAC-layer packet grouping of data that is grouped to fit into one MAC-layer packet of CSMA/CD networks, and wherein the half duplex communications are half-duplex with respect to MAC-layer packet groupings of data;
communicating control information for controlling the half duplex communications via the bidirectional communications path from the first modem to the second modem;
and
changing direction of flow on the bidirectional communications path for the information corresponding to the information packets, the direction of flow changing based at least upon completion of communication associated with conveying information corresponding to at least one MAC-layer packet grouping of data across at least one of the first end interface and the second end interface.

4 more elements

A method of communicating information packets to and from a CSMA/CD (Carrier Sense Multiple Access with Collision Detection) path via communication of information corresponding to the information packets over a bidirectional communications path, the information packets comprising upstream information packets and downstream information packets, the method comprising the steps of:

coupling a first end of the bidirectional communications path to a first modem, wherein the first modem is coupled to the first end of the bidirectional communications path via a first end interface;
communicating the information packets between the CSMA/CD path and the first modem via a CSMA/CD interface, wherein each of the information packets comprises a MAC-layer packet grouping of data that is grouped to fit into one MAC-layer packet of CSMA/CD networks, and wherein the half duplex communications are half-duplex with respect to MAC-layer packet groupings of data;
coupling a second end of the bidirectional communications path to a second modem, wherein the second modem is coupled to the second end of the bidirectional communications path via a second end interface;
communicating information corresponding to the downstream information packets and control information, for controlling operation of the second modem, from the first modem to the second modem via the bidirectional communications path;
changing direction of flow for the information corresponding to the information packets, the direction of flow changing based at least upon completion of communication associated with conveying information corresponding to at least one MAC-layer packet grouping of data across at least one of the first end interface and the second end interface;
and
communicating information corresponding to the upstream information packets from the second modem to the first modem via the bidirectional communications path under control of the control information, the control information providing half duplex communications for at least the information corresponding to the information packets on the bidirectional communications path.

4 more elements

A method of communicating Ethernet frames on a CSMA/CD (Carrier Sense Multiple Access with Collision Detection) path via communication of information corresponding to the Ethernet frames over a bidirectional communications path, the method comprising the steps of:

coupling the information corresponding to the Ethernet frames between the CSMA/CD path and a first modem via a CSMA/CD interface, wherein the first modem is further coupled to the bidirectional communications path via a first end interface;
and
coupling the information corresponding to the Ethernet frames between the first modem and a second modem via the bidirectional communications path, wherein each of the Ethernet frames comprises a MAC-layer packet grouping of data that is grouped to fit into one MAC-layer packet of CSMA/CD networks, wherein the second modem is coupled to the bidirectional communications path via a second end interface, wherein the first and second modems are master and slave modems respectively, and the master modem controls the slave modem by control information communicated via the bidirectional communications path so that communications of at least the information corresponding to the Ethernet frames on the bidirectional communications path take place in a half-duplex manner, wherein the half-duplex manner is half-duplex with respect to MAC-layer packet groupings of data, the half duplex manner of communications changing direction of flow for the information corresponding to the Ethernet frames, the direction of flow changing based at least upon completion of communication associated with conveying information corresponding to at least one MAC-layer packet grouping of data across at least one of the first end interface and the second end interface.

A method of communicating information corresponding to information packets in both directions between a CSMA/CD (Carrier Sense Multiple Access with Collision Detection) path and a bidirectional communications path, the information packets being, the method comprising the steps of:

coupling the information corresponding to the information packets from the CSMA/CD path via a CSMA/CD interface to a first buffer, wherein the first buffer is coupled to the bidirectional communications path via a first end interface;
supplying the information corresponding to the information packets from the first buffer to the bidirectional communications path under control of a control unit, wherein each of the information packets comprises a MAC-layer packet grouping of data that is grouped to fit into one MAC-layer packet of CSMA/CD networks;
changing direction of flow for the information corresponding to the information packets, the direction of flow changing based at least upon completion of communication associated with conveying information corresponding to at least one MAC-layer packet grouping of data across at least one of the first end interface and the second end interface, the changing of the direction of flow being a characteristic of communications in a half duplex manner, wherein the half duplex manner is half-duplex with respect to MAC-layer packet groupings of data;
receiving the information corresponding to the information packets from the first buffer to the bidirectional communications path in a second buffer, wherein the second buffer is coupled to the bidirectional communications path via a second end interface;
coupling the information corresponding to the information packets from the second buffer to the CSMA/CD path via the CSMA/CD interface;
and
producing in the control unit and supplying to the bidirectional communications path, or receiving from the bidirectional communications path and supplying to the control unit, control information, the control information communicated to provide that communications of the information corresponding to the information packets via the bidirectional communications path take place in the half duplex manner.

4 more elements

coupling a first end of the bidirectional communications path to the first CSMA/CD path via a first modem coupled to the CSMA/CD path, wherein the first modem is coupled to the first end of the bidirectional communications path via a first end interface;
communicating the information packets between the CSMA/CD path and the first modem via a CSMA/CD interface;
coupling a second end of the bidirectional communications path to a second modem, wherein the second modem is coupled to the second end of the bidirectional communications path via a second end interface;
communicating information corresponding to the information packets between the first and second modems via the bidirectional communications path using half duplex communications controlled by the first modem, wherein each of the information packets comprises a MAC-layer packet grouping of data that is grouped to fit into one MAC-layer packet of CSMA/CD networks, and wherein the half duplex communications are MAC-layer half-duplex such that once information corresponding to a first MAC-layer packet grouping of data has begun to be transmitted into the bidirectional communications path the information corresponding to the first MAC-layer packet grouping of data is completely transmitted into the bidirectional communications path before information corresponding to a second MAC-layer packet grouping of data is allowed to begin to be transmitted into the bidirectional communications path;
and
communicating control information for controlling the MAC-layer half duplex communications via the bidirectional communications path from the first modem to the second modem.

3 more elements

Dependencies are inferred from the claim text.

Information network access apparatus and methods for communicating information packets via telephone lines

Life of this patent

Information network access apparatus and methods for communicating information packets via telephone lines

Life of this patent

Abstract

Claims42