Hybrid access system with quality-based channel switching

• US 5,828,655 A
• Filed: 08/21/1996
• Issued: 10/27/1998
• Est. Priority Date: 04/21/1995
• Status: Expired due to Fees

• Current Assignee: Hybrid Patents Incorporated
• Original Assignee: Hybrid Networks, Inc. (Iowave, Inc.)
• Inventors: Moura, Eduardo J., Gronski, Jan Maksvmilian
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US08/700,991
• Time in Patent Office: 797 Days
• Field of Search: 370/201, 370/241, 370/237, 370/252, 370/227, 370/228, 370/236, 370/404, 370/486, 370/276, 455/67.1, 455/63, 455/33.2, 455/33.3, 455/34.2, 455/266.1, 375/227, 375/244
• US Class Current: 370/236
• CPC Class Codes: H04B 7/18523 Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service arrangements specially adapted for satellite broadcast receiving H04H40/90; picture transmission via satellite H04N1/00103; television transmission via satellite H04N7/20
• CPC Class Codes: H04B 7/18584 Arrangements for data networking, i.e. for data packet routing, for congestion control data switching networks H04L12/00
• CPC Class Codes: H04H 20/38 Arrangements for distribution where lower stations, e.g. receivers, interact with the broadcast
• CPC Class Codes: H04H 20/78 CATV [Community Antenna Television] systems
• CPC Class Codes: H04H 20/81 combined with telephone network over which the broadcast is continuously available
• CPC Class Codes: H04H 60/82 the transmission system being the Internet
• CPC Class Codes: H04J 3/1682 Allocation of channels according to the instantaneous demands of the users, e.g. concentrated multiplexers, statistical multiplexers
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2898 Subscriber equipments DSL modems H04M11/062; cable modems H04L12/2801
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04N 21/2381 Adapting the multiplex stream to a specific network, e.g. an Internet Protocol [IP] network transmission of MPEG streams over ATM H04L12/5601
• CPC Class Codes: H04N 21/2393 : involving handling client requests scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/2408 : Monitoring of the upstream path of the transmission network, e.g. client requests monitoring data switching networks utilization H04L43/0876; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/266 : Channel or content management, e.g. generation and management of keys and entitlement messages in a conditional access system, merging a VOD unicast channel into a multicast channel
• CPC Class Codes: H04N 21/437 : Interfacing the upstream path of the transmission network, e.g. for transmitting client requests to a VOD server flow control in data networks H04L47/10; streaming protocols, e.g. RTP or RTCP, H04L65/65; scheduling or organising the servicing of application requests in data packet switching networks H04L67/60
• CPC Class Codes: H04N 21/64322 : IP
• CPC Class Codes: H04N 7/10 : Adaptations for transmission by electrical cable H04N7/12 takes precedence
• CPC Class Codes: H04N 7/17309 : Transmission or handling of upstream communications
• CPC Class Codes: H04N 7/17345 : Control of the passage of the selected programme
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate
• CPC Class Codes: Y10S 370/911 : Bridge, e.g. brouter, bus extender

Abstract

An asymmetric network communication system for use in a client-server environment having independent forward and return channels operating at different speeds and/or under different protocols on the same or different communication media to provide efficient utilization of shared resources. A network manager, such as a hybrid access system, effects transmission of packetized data on a forward (downstream) channel from the host server to multiple client devices coupled with a shared downstream media at 10 or more megabits per second while simultaneously providing selectable multiple lower speeds of operation on shared or dedicated return (upstream) channels from the client devices to the host server depending on bandwidth availability, bandwidth demand, service level authorization, etc. for the return channel. Forward and return channels may be located on the same or different communication medium including a CATV network, direct broadcast satellite network, television or radio RF broadcast network, wireless or mobile cellular facilities or the like. The return channel may reside on a PSTN either directly coupled with the host server or connected with the network manager for subsequent transmission to the host server. The network manager handles or controls the forward and return communication to establish interactive full-duplex real-time network sessions between the host and a selected client device. The network manager switches upstream channel assignment based on quality of signals transmitted to the host. The system effects changes in the upstream transmitted power based on sensed conditions.

Claims

1. A method of providing two way asymmetric network communication between a host and a remote device that is capable of establishing client-server communication with said host, said method comprising:

providing a shared medium,

providing a high speed downstream channel and plural associated lower speed upstream channels wherein the downstream channel conveys data packets from the host to the remote device over said shared medium at rate that is higher than a rate of conveyance of data packets from the remote device to the host over said shared medium in a lower speed upstream channel,

providing an interface associated with said remote device for receiving high speed downstream data packets originating from said host over said downstream channel and for sending lower speed data packets destined for said host over one of said lower speed upstream channels,

controlling at least one of switching and routing functions of paths of both said downstream and upstream channels according to at least one of a request for access to a channel and a request to transfer data initiated by at least one of said host and remote device,

in response to said controlling step, transferring at least one of high speed data packets originating from said host according to a high speed downstream protocol and lower speed data packets originating from said remote device to said host according to a lower speed upstream protocol,

during said transferring step, detecting a level of a quality characteristic of signals in at least one of said upstream channels,

determining whether the level of detected quality characteristic deviates with respect to a predefined norm, and

switching to another channel, if sufficient deviation is determined.

2. The method according to claim 1, wherein said group of quality characteristics includes time from last operability indication, signal to noise ratio and error frequency.

3. A method of providing two way asymmetric network communication between a server and a plurality of remote clients comprising the steps of:

providing a shared medium,

providing said remote clients with associated interfaces for receiving high speed downstream information from said server over a downstream channel via said shared medium and for sending lower speed return information over a lower speed upstream channel via said shared medium,

controlling, at a network layer or link layer, at least one of switching and routing functions of paths of both said downstream and upstream channels according to at least one of a request for assignment of a channel and a request to transfer information initiated by at least one of said server and said plurality of remote clients,

in response to said controlling step, transferring at least one of high speed information from said host according to a high speed downstream protocol and lower speed information from said remote device to said server according to a lower speed upstream protocol, and

dynamically switching to a selected upstream communication channel in response to a detected quality characteristic by

detecting a quality characteristic with respect to an upstream communication channel and

switching to another communication channel based on the detected quality characteristic.

4. The method as in claim 3 wherein said step of switching comprises the step of

switching to another communication channel if the detected quality characteristic deviates sufficiently from a predetermined norm.

5. The method according to claim 3 wherein said quality characteristic is one of time from last operability indication, signal-to-noise ratio, error frequency and busy signal.

6. The method according to claim 3 wherein said shared medium comprises one of a hybrid fiber coaxial cable, an over-the-air broadcast medium, a cellular broadcast medium, a direct satellite broadcast medium, a CATV broadcast and an rf radio broadcast and wherein said upstream channel is one of a selected lower speed upstream channel located on said shared medium, a lower speed telephone return line, a lower speed cellular return channel, an over-the-air rf transmission and a point-to-point electromagnetic transmission.

7. The method according to claim 3, wherein said switching to another communication channel comprises the steps of:

determining the availability of at least one channel;

selecting as the other channel a suitable channel from the available channels; and

switching to the other channel.

8. The method according to claim 7, wherein said step of selecting a suitable channel is based on suitability factors of the available channels, said factors including at least one of channel quality, type of service required, operating characteristics of a client associated with said communication channel and configuration restrictions.

9. The method according to claim 7, wherein said switching to the other channel comprises the steps of:

sending a message to a client associated with said communication channel, said message requesting said client to switch to said other channel; and

receiving a response from said client on the other channel.

10. The method as in claim 3 wherein said communication channel is an upstream channel and wherein said step of detecting is performed at an upstream location.

11. A method of providing two way asymmetric communication over a shared medium comprising:

providing a high speed downstream channel and plural lower speed upstream channels in said share medium,

providing a host,

providing a plurality of remote interfaces that communicate with said host over said shared medium via said plural lower speed upstream channels,

controlling assignment of an upstream channel to at least one of said remote interfaces by polling said remote interfaces to detect a request for channel access by at least one of said remote interfaces,

in response to said controlling, assigning an upstream channel to said at least one of said remote interfaces,

transferring information from one of said remote interfaces over an assigned upstream channel,

during said transferring, dynamically responding to a quality characteristic of said assigned upstream channel by detecting said quality characteristic with respect to said upstream channel; and

switching to another communication channel based on a predetermined detected quality characteristic.

12. The method as in claim 11 wherein said step of switching comprises the step of switching to another communication channel if at least one of the detected quality characteristics deviates sufficiently from corresponding predetermined norm.

13. The method as in claim 11 wherein said step of switching comprises the step of

switching to another communication channel based on sufficient deviation of detected quality characteristics from corresponding predetermined norms.

14. The method according to claim 11 wherein said quality characteristics are selected from time from last operability indication, signal-to-noise ratio, error frequency and busy signal.

15. A two way asymmetric communication system for transferring information between a host and a remote device comprising:

a shared medium,

at least one downstream channel in said shared medium,

plural lower speed upstream channels in said share medium,

a remote interface associated with said remote device for receiving high speed downstream information from said host over said downstream channel and for sending lower speed return information over at least one of said lower speed upstream channels,

a control system common to both upstream and downstream channels that is co-located with a headend facility of a data distribution network for managing access to said upstream channels by said remote interfaces and for enabling the transfer of information over said downstream and upstream channels,

said control system dynamically responding to quality of a communication channel and including

a detector that detects a quality characteristic with respect to the communication channel and

a channel switching device for switching to another communication channel based on the detected quality characteristic.

16. The system as in claim 15 wherein said switching device comprises means for switching to another communication channel if the detected quality characteristic deviates sufficiently from a predetermined norm.

17. The system according to claim 15 wherein said quality characteristic is one of time from last operability indication, signal-to-noise ratio, error frequency and busy signal.

18. The system according to claim 15 wherein said shared medium comprises one of a hybrid fiber coaxial cable, an over-the-air broadcast medium, a cellular broadcast medium, a direct satellite broadcast medium, a CATV broadcast and an rf radio broadcast and wherein said upstream channel is one of a selected lower speed upstream channel located on said shared medium, a lower speed telephone return line, a lower speed cellular return channel, an over-the-air rf transmission and a point-to-point electromagnetic transmission.

19. The system according to claim 15, wherein said means for switching to another communication channel comprises:

equipment for determining the availability of at least one channel;

a channel selector for selecting as the other channel a suitable channel from the available channels; and

a switching device for switching to the other channel.

20. The system according to claim 19, wherein said channel selector operates to switch channels based on suitability factors of the available channels, said factors including at least one of channel quality, type of service required, operating characteristics of a client associated with said communication channel and configuration restrictions.

21. The system according to claim 19, wherein said channel selector comprises:

means for sending a message to a client associated with said communication channel, said message requesting said client to switch to said other channel; and

a receiver for receiving a response from said client on the other channel.

22. The system as in claim 15 wherein said communication channel is an upstream channel and wherein said detector operates at an upstream location.

23. A two way asymmetric network communication system for transferring information between a server and a plurality of remote clients over a shared medium comprising:

a high speed downstream channel in said shared medium,

a lower speed upstream channel,

plural remote interfaces associated with respective remote clients for receiving high speed downstream information from said server over said downstream channel and for sending lower speed return information over said lower speed upstream channel,

a network management system common to both upstream and downstream channels and being located at a central facility for simultaneously effecting control of information transfers over said downstream and upstream channels, said network management system further including,

a device for dynamically responding to quality of a communication channel including,

a detector that detects a plurality of quality characteristics with respect to the communication channel and

a switching device for switching to another communication channel based on the detected quality characteristics.

24. The system as in claim 23 wherein said switching device comprises means for

switching to another communication channel if at least one of the detected quality characteristics deviates sufficiently from corresponding predetermined norm.

25. The system as in claim 23 wherein said switching device comprises:

means for switching to another communication channel based on sufficient deviation of detected quality characteristics from corresponding predetermined norms.

26. The system according to claim 23 wherein said quality characteristics are selected from time from last operability indication, signal-to-noise ratio, error frequency and busy signal.

27. In an asymmetric network communication system including a first node, a plurality of second nodes, spacially removed from the first node, a first channel for sending packets from the first node to the plurality of second nodes over a downstream channel at a high speed data rate in a shared medium, and a plurality of second channels for sending packets from the second nodes to the first node over an upstream channel at a lower speed data rate in the shared medium, a method comprising the step, performed in one of the second nodes, of:

sending a signal on a second channel in the plurality of second channels at the lower speed data rate,

and the steps, performed at a location spacially removed from the one of the second nodes, of;

controlling at least one of switching and routing functions of both the downstream and upstream channels according to at least one of a request for access to a channel and a request to transfer data initiated at one of the first node and the second nodes;

in response to the controlling step, transferring at least one of high speed packets originating at the first node according to a high speed downstream protocol and lower speed packets originating at the second node according to a lower speed upstream protocol;

monitoring a quality of the second channel to generate a result; and

conditionally directing the one of the second nodes to send the signal on another channel, depending on the monitoring step.

28. The method of claim 27 wherein the plurality of second channels are in the cable network, and the sending step includes;

sending the signal over the cable network.

29. The method of claim 27 wherein the first channel is in a cable network, and the plurality of second channels are in the cable network, each of the plurality of second channels having respective frequencies in the cable network, each of the plurality having second channels operating at a lower speed than a speed of the first channel, and the sending step includes:

sending the signal over the cable network.

30. The method of claim 27 wherein the first channel is in a cable network, and the plurality of second channels are in the cable network, each of the plurality of second channels having a respective time slot within the cable network, and the sending step includes:

sending the signal over the cable network.

31. The method of claim 27 wherein the first channel is in a wireless broadcast network, and the plurality of second channels are in the wireless broadcast network, each of the plurality of second channels having respective frequencies in the wireless broadcast network, each of the plurality having second channels operating at a lower speed than a speed of the first channel, and the sending step includes;

sending the signal over the wireless broadcast network.

32. The method of claim 27 wherein the first channel is in a wireless broadcast network, and the plurality of second channels are in the wireless broadcast network, each of the plurality of second channels having a respective time slot in the wireless broadcast network, and the sending step includes:

sending the signal over the wireless broadcast network.

33. The method of claim 27 wherein the first channel is in a wireless broadcast network, and the plurality of second channels are in the wireless broadcast network, and the sending step includes:

sending the signal over the wireless broadcast network.

34. The method of claim 27 wherein the first channel is in a selected one of:

a CATV network, over-the-air wireless broadcast, an RF broadcast, an electromagnetic transmission, a coaxial cable network, direct broadcast satellite transmission, telephone network, hybrid fiber coaxial network and a cellular broadcast system, and the plurality of second channels are in a selected one of;

a CATV network, over-the-air wireless broadcast, an RF broadcast, an electromagnetic transmission, a coaxial cable network, direct broadcast satellite transmission, telephone network, hybrid fiber coaxial network and a cellular broadcast system, and the sending step includes;

sending the signal over the selected one of;

a CATV network, over-the-air wireless broadcast, an RF broadcast, an electromagnetic transmission, a coaxial cable network, direct broadcast satellite transmission, telephone network, hybrid fiber coaxial network and a cellular broadcast system.

35. An asymmetric network communication system comprising:

a first node;

a plurality of second nodes, spacially removed from the first node;

a first channel for sending packets from the first node to the plurality of second nodes at a high data rate over a downstream channel in a shared medium; and

a plurality of second channels for sending packets from the second nodes to the first node at a lower data rate over an upstream channel in the shared medium, wherein each second node includes

circuitry that sends a signal on a respective second channel in the plurality of second channels,

and the system further includes,

a control unit that controls at least one of switching and routing functions of both the downstream and upstream channels according to at least one of a request for access to a channel and a request to transfer data initiated at one of the first node and the second nodes, the control unit enabling the transfer of at least one of high speed packets originating at the first node according to a high speed downstream protocol and lower speed packets originating at the second node according to a lower speed upstream protocol in response to control of at least one of the switching and routing, and

a monitor, spacially removed from the second nodes, that monitors a quality of each of the plurality of second channels, to conditionally direct one of the second nodes to send the signal on another channel.

36. The system of claim 35 further including:

a cable network,

wherein the first channel is in the cable network, and the plurality of second channels are in the cable network.

37. The system of claim 35 further including:

a cable network,

wherein the first channel is in the cable network, and the plurality of second channels are in the cable network, each of the plurality of second channels having respective frequencies in the cable network, each of the plurality having second channels operating at a lower speed than a speed of the first channel.

38. The system of claim 35 further including:

a cable network,

wherein the first channel is in the cable network, and the plurality of second channels are in the cable network, each of the plurality of second channels having a respective time slot within the cable network.

39. The system of claim 35 further including:

a wireless broadcast network,

wherein the first channel is in the wireless broadcast network, and the plurality of second channels are in the wireless broadcast network, each of the plurality of second channels having respective frequencies in the wireless broadcast network, each of the plurality having second channels operating at a lower speed than a speed of the first channel.

40. The system of claim 35 further including:

a wireless broadcast network,

wherein the first channel is in the wireless broadcast network, and the plurality of second channels are in the wireless broadcast network, each of the plurality of second channels having a respective time slot in the wireless broadcast network.

41. The system of claim 35 further including:

a satellite broadcast network; and

a wireless broadcast network,

wherein the first channel is in the satellite broadcast network, and the plurality of second channels are in the telephone network, each of the plurality of second channels having a respective time slot in the wireless broadcast network.

42. The system of claim 35 wherein the first channel is in a selected one of:

a CATV network, over-the-air wireless broadcast, an RF broadcast, an electromagnetic transmission, a coaxial cable network, direct broadcast satellite transmission, telephone network, hybrid fiber coaxial network and a cellular broadcast system, and the plurality of second channels are in a selected one of;

a CATV network, over-the-air wireless broadcast, an RF broadcast, an electromagnetic transmission, a coaxial cable network, direct broadcast satellite transmission, telephone network, hybrid fiber coaxial network and a cellular broadcast system.

43. A method of providing two way asymmetric network communication between a host and a remote device that is capable of establishing client-server communication with said host, said method comprising:

providing a shared medium,

providing a high speed downstream channel and plural associated lower speed upstream channels wherein the downstream channel conveys data packets from the host to the remote device over said shared medium at a rate that is higher than a rate of conveyance of data packets from the remote device to the host over said shared medium in a lower speed upstream channel,

providing an interface associated with said remote device for receiving high speed downstream data packets originating from said host over said downstream channel and for sending lower speed data packets destined for said host over one of said lower speed upstream channels,

controlling at least one of switching and routing functions of both said downstream and upstream channels according to at least one of a request for access to a channel and a request to transfer data initiated by at least one of said host and remote device, and

in response to said controlling step, transferring at least one of high speed data packets originating from said host according to a high speed downstream protocol and lower speed data packets originating from said remote device to said host according to a lower speed upstream protocol.

44. A method of providing two way asymmetric network communication between a server and a plurality of remote clients comprising the steps of:

providing a shared medium,

providing said remote clients with associated interfaces for receiving high speed downstream information from said server over a downstream channel via said shared medium and for sending lower speed return information over a lower speed upstream channel via said shared medium,

controlling, at a network layer or link layer, at least one of switching and routing functions of both said downstream and upstream channels according to at least one of a request for assignment of a channel and a request to transfer information initiated by at least one of said server and said plurality of remote clients, and

in response to said controlling step, transferring at least one of high speed information from a host according to a high speed downstream protocol and lower speed information from a remote device to said server according to a lower speed upstream protocol.