Method and apparatus for controlling communication channels using contention and polling schemes

• US 6,275,497 B1
• Filed: 08/27/1997
• Issued: 08/14/2001
• Est. Priority Date: 02/10/1997
• Status: Expired due to Fees

• Current Assignee: Hybrid Patents Incorporated
• Original Assignee: Hybrid Networks, Inc. (Iowave, Inc.)
• Inventors: Varma, Subir, Enns, Frederick
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Sam, Phirin
• Application Number:
  US08/917,735
• Time in Patent Office: 1,448 Days
• Field of Search: 370/431, 370/443, 370/444, 370/445, 370/447, 370/449, 370/450, 370/455, 370/459, 370/461, 370/462, 370/333, 370/463, 370/487, 370/346, 370/347, 370/348, 370/451 , 370/322, 370/270, 370/420, 370/421, 370/423, 370/424, 370/432, 370/433, 370/460, 340/825.08, 340/825.5, 340/825.51, 340/825.52
• US Class Current: 370/431
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/62 Establishing a time schedule for servicing the requests
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A medium access controller for a multi-user network that assigns or changes the operating protocol of multiple upstream channels according to user loading, user status, and/or type of payload data transfers requested by the user or detected by the controller. One group of upstream channels utilizes a contention-only protocol for non-responding or off-line users, a second group utilizes a limited type polling protocol for users requiring only brief transfers of payload data, and a third group utilizes an exhaustive polling protocol user requiring large amounts of payload data transfers. Limited type polling provides low latency for quick response to accommodate multiple users, while exhaustive polling provides large data throughput at the expense of latency. Additional levels of limited or exhaustive polling may be employed to accommodate a larger variety of users needs. In addition, the channels themselves may be dynamically reclassified between and among contention and first and/or other level polling modes based on user loading and/or the nature and character of on-going data transfers in order to achieve maximum utilization of shared resources. After initiating a data transmission, the controller may also dynamically assign channels to a user based on detected changes in actual data transmissions. Thus, rules based on user activity level may be implemented to determine when a user is switched between channel groups. Essentially, the controller may effect switching of the users'"'"' upstream channels dynamically and intelligently on a packet-by-packet basis. Users may include modems and/or other terminal devices in a client-server or other data communication network.

Claims

1. A two way network communication system including a controller and plural client devices, said system comprising:

a downstream medium over which said client devices receive data;

an upstream medium including at least three upstream channels for conveying data from said client devices

one of said upstream channels operating in a contention mode, another of said upstream channels operating in a low-latency and yet another of said upstream channels operating in a burst mode, a relatively higher data throughput polling mode, wherein at least one of said channels is alterable between a polling mode and a contention mode;

said controller being operative to assign to a client device any one of said at least upstream channels based on a bandwidth characteristic of payload data transferred by said client device.

2. The system according to claim 1, wherein:

said controller monitors data transmissions of the client device over an upstream channel and dynamically effects assignment of the upstream channel based on a per data packet basis.

3. The system according to claim 1, further comprising:

a plurality of sets of said at least three upstream channels; and

said controller effects assignment of upstream channels from among said plurality of sets.

4. The system according to claim 1, wherein:

said characteristic is a frequency of payload data transmissions from the client device.

5. The system according to claim 1, wherein:

said characteristic is a length of payload data queued for transmission.

6. The system as recited in claim 1, wherein at least one of said polling modes channels is dedicated to a group of client devices.

7. The system as recited in claim 1, wherein at least one of said channels is alterable between a polling mode and a contention mode as a function of one of user loading.

8. The system as recited in claim 1, wherein said upstream and downstream medium are common.

9. The system as recited in claim 1, wherein said upstream medium and downstream medium are different.

10. The system as recited in claim 1, wherein said system provides asymmetric communication over said upstream and downstream media.

11. A method of utilizing a broadband channel for data communications between a controller and a plurality of user, said method comprising:

sub-dividing said broadband channel into at least three separate data channels for upstream communications;

assigning a first group of currently inactive ones of said plurality of users to a first channel of said at least three separate data channels for upstream communications;

assigning a second group of active ones of said plurality of users to a second channel of said at least three separate data channels, for upstream communications;

assigning a third group of relatively more active ones of said plurality of users to a third channel of said at least three separate data channels for upstream communications;

wherein said plurality of users are reassigned by said controller between one of the first, second and third channels for upstream communications based on a bandwidth characteristic of payload data transmitted by respective ones of said plurality of users.

12. The method of utilizing a plurality of communication channels according to claim 11, wherein:

said plurality of users are reassigned between said second and third channels to separate active ones of said plurality of users with a short packet latency requirement from relatively more active ones of said plurality of users with a high packet throughput requirement.

13. The method of utilizing a plurality of communication channels according to claim 11, wherein:

said first channel is operated in a contention mode; and

said second channel and said third channel are operated in different respective polling modes.

14. The method of utilizing a plurality of communication channels according to claim 13, wherein:

said second channel is operated in a limited polling scheme protocol; and

said third channel is operated in an approximately exhaustive polling scheme protocol.

15. The method of communicating according to claim 11, wherein:

said characteristic is a frequency of payload data transmissions from said user.

16. The method of communicating according to claim 11, wherein:

said characteristic is a length of said payload data packet queued for transmission.

17. An asymmetric data communication system comprising:

a controller;

a plurality of users;

a downstream channel for conveying information from said controller to said plurality of users; and

a plurality of upstream channels for conveying information from said plurality of users to a host, said plurality of users having accessibility to all or some of said plurality of upstream channels but being assigned to only one of said plurality of upstream channels for transmission at any one time;

a first of said plurality of upstream channels operating in a contention mode;

a second of said plurality of upstream channels operating in a more limited polling mode;

a third of said plurality of upstream channels operating in a burst mode, a relatively higher data throughput mode;

said plurality of users being assigned and reassigned between said first and second of said plurality of upstream channels based on a bandwidth characteristic of payload data transmitted by said respective plurality of users; and

said plurality of users being assigned and reassigned between said second and third of said plurality of upstream channels based on a different bandwidth characteristic of payload data transmitted by said respective plurality of users.

18. The asymmetric communication system according to claim 17, wherein:

said characteristic is a frequency of payload data transmissions from said user.

19. The asymmetric communication system according to claim 17, wherein:

said characteristic is a length of payload data queued for transmission.

20. In an asymmetric network communication system including a server, plural clients and asymmetric communication channels interposed between said server and client that include a downstream channel and plural upstream channels, the improvement comprising:

a controller that enables said clients to share said plural upstream channels wherein respective ones of said plural upstream channels operate under respective protocols including a contention protocol, a limited polling protocol and a more exhaustive polling protocol;

at least one of said clients including a first status indicator indicative of at least an inactive status and an active status thereof depending on a need to transfer data and an associated second status indicator indicative of bandwidth needs during active data tansfers of payload data by said at least one of said clients; and

said controller being responsive to said first indicator to assign a client to an upstream channel having said contention protocol in the absence of a data transfer request and responsive to said second indicator to dynamically assign said at least one client to said upstream channel having one of said limited and more exhaustive polling protocols according to the instantaneous bandwidth reguest or consumption of said client during active transfer of said payload data by said at least one client.

21. A media access control system for use in an asymmetric network communication system which includes a server, plural client devices and asymmetric channels interposed between said server and client devices, said asymmetric network including at least one downstream channel and plural upstream channels that operate under respective protocols including a contention protocol, a low bandwidth polling protocol and a high bandwidth polling protocol, said low bandwidth polling protocol being adapted to handle data transfers at relatively low average rates and said high bandwidth polling protocol being adapted to handle data transfers at relatively higher average rates, said control system comprising:

a demand indicator associated with at least one client device indicative of a status depending on a data transfer request by said client;

a consumption indicator indicative of data transfer needs of said client device during active data transfers of payload data by said client device; and

a controller responsive to said demand indicator to assign said client to an upstream channel having a contention protocol in the absence of said data transfer request and responsive to said consumption indicator to dynamically assign said client device to said upstream channel having one of said high and low bandwidth polling protocols according to the payload data transfer needs of said client device for active transfers of payload data by said client device.

22. A two way networking communication system including a controller and plural client devices, said system comprising:

a shared downstream medium over which data is conveyed to said client devices,

an upstream medium including at least three available upstream channels over which data is conveyed from said client devices;

one of said at least three upstream channels operating in a contention mode and two of said at least three upstream channels operating in respective different polling modes;

said controller being operative to assign to said client device any one of said at least three upstream channels based on a bandwidth characteristic of payload data transferred by said client device;

wherein one of said two polling mode upstream channels has a limited polling scheme; and

the other of said two polling mode upstream channels has an approximately exhaustive polling burst mode.

23. A method of communicating between a controller and a plurality of client devices, comprising:

providing a downstream communication channel over a shared medium;

providing a plurality of upstream communication channels within said medium;

assigning currently inactive ones of said plurality of client devices to one of said plurality of upstream communication channels operating in a contention mode;

assigning currently active ones of said plurality of client devices to either of said at least two of said plurality of upstream communication channels operating in respective polling modes, one polling mode operating in a more limited mode, the second operating in a relatively higher data throughput mode active burst mode; and

said assignment being based on a bandwidth characteristic of payload data transmitted by respective ones of said plurality of client devices.

24. The method of communicating according to claim 23, further comprising:

providing one of said two others of said plurality of upstream channels with a limited polling scheme; and

providing the other of said two others of said plurality of upstream channels with an approximately exhaustive polling scheme.

25. The method of communicating according to claim 23, wherein:

said characteristic is a recurrence of payload data transmissions from said user.

26. The method of communicating according to claim 23, wherein:

said characteristic is a length of said payload data packet queued for transmission.

27. A method of communicating between the controller and a plurality of users, comprising:

providing a downstream communication channel;

providing a plurality of upstream communication channels;

assigning currently inactive ones of said plurality of users to one of said plurality of upstream communication channels operating in a contention mode;

assigning currently active ones of said plurality of users to either of at least two of said plurality of upstream communication channels operating in respective polling modes, said assignment being based on a bandwidth characteristic of payload data transmitted by respective ones of said plurality of users;

from the perspective of said users, providing one of said two others of said plurality of upstream channels with a low latency polling scheme; and

providing the other of said two others of said plurality of upstream channels with polling scheme providing a relatively higher data throughput also from the perspective of said users.

28. A method of communicating between a controller and a plurality of users in a communication network, comprising:

providing a downstream communication channel;

providing a plurality of upstream channels operable in a burst mode, a more limited polling mode, or a contention mode, each mode having different user latency and/or throughput rates;

altering the mode of at least one of said plurality of upstream channels between said burst mode, more limited polling mode, and said contention mode as a function of user loading; and

assigning respective ones of said plurality users to one of said plurality of upstream channels.