Method and apparatus for controlling communication within a computer network

• US 7,251,231 B2
• Filed: 02/21/2003
• Issued: 07/31/2007
• Est. Priority Date: 09/11/1998
• Status: Expired due to Term

• Current Assignee: Cirrus Logic Incorporated
• Original Assignee: Cirrus Logic Incorporated
• Inventors: Gubbi, Rajugopal
• Primary Examiner(s): Phunkulh, Bob A.
• Application Number:
  US10/371,824
• Publication Number:
  US 20030219030A1
• Time in Patent Office: 1,621 Days
• Field of Search: None
• US Class Current: 370/336
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 12/2816 Controlling appliance services of a home automation network by calling their functionalities arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station; in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom H04Q9/00
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 2012/2841 Wireless
• CPC Class Codes: H04L 2012/2849 Audio/video appliances
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/2866 Architectures; Arrangements
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 21/43615 Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals home Audio Video Interoperability [HAVI] data switching networks H04L12/2805
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 84/02 Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]

Abstract

A communication channel is controlled so as to dynamically accommodate network client requests for access thereto. The communication channel may be supported on a wireless link, such as a spread spectrum wireless link, and client requests for access thereto may be dynamically accommodated by allocating time slots for client transmissions on the wireless link. Providing a quiet time slot within which clients may request access to the communication channel may accommodate various client requests for access to the communication channel. These quiet slots may exist with other forward and reverse time slots which are superimposed on the communication channel, each forward and reverse time slot including one or more data frames. The forward and reverse time slots are preferably fixed, but negotiable, time periods. Each of the data frames may include a plurality of data packets, each of the data packets being variable in length. Preferably, each of the data packets includes error correction coding information as well as information which may be used to synchronize pseudo-random number generators of a transmitter and a receiver operating according to the communication protocol. Each of the data frames may further include link identification information that uniquely identifies a wireless link supporting the communication protocol.

Claims

1. A method for data communication in a wireless network including a server and a plurality of existing clients, the method includes a protocol for the wireless network comprising:

organizing data transmission within the wireless network into a sequence of data frames wherein each frame includes;

a first portion having a plurality of forward time slots for transmission of data from the server to the plurality of existing clients;

a second portion having a plurality of reverse time slots for transmission of data from the plurality of existing clients to the server;

a turn-around portion selectively inserted between the first and second portions for selectively supporting half-duplex communications between the server and the plurality of existing clients; and

a dedicated quiet portion independent from the first and second portions during which neither the server nor the existing clients transmit;

wherein, one or more forward and reverse time slots are assigned to each client by the server, and the assignments remain in effect for succeeding data frames until changed by the server;

transmitting data from the server to the one of the plurality of existing clients over one or more of the assigned forward time slots; and

transmitting data from one of the plurality of existing clients to the server over one or more of the assigned reverse time slots.

2. The protocol of claim 1, wherein each of the forward time slots and each of the reverse time slots are of a predetermined fixed duration.

3. The protocol of claim 2, wherein the number of forward and reverse time slots assigned to an existing client is based on the bandwidth requirements of the existing client.

4. The protocol of claim 3, wherein the number of forward time slots assigned to a client is different from the number of reverse time slots assigned to the existing client.

5. The protocol of claim 1, wherein the duration of each forward time slot and each reverse time slot is assigned by the server.

6. The protocol of claim 5, wherein the assigned duration of each forward and reverse time slot remains constant for successive frames until changed by the server.

7. The protocol of claim 6, wherein the duration of an assigned forward or reverse time slot is based on the bandwidth requirements of the client to which the time slots are assigned.

8. The protocol of claim 1, wherein a new client:

monitors data frames on the wireless network to discover the quiet portion of the data frame; and

transmits a request to join the wireless network during the quiet portion of the data frame.

9. The protocol of claim 8, wherein the quiet portion of a data frame has a duration substantially shorter than the duration of either the forward or reverse portions of the data frame.

10. The protocol of claim 1, wherein the duration of a data frame on the network corresponds to the duration of a video frame.

11. A system for efficiently utilizing bandwidth in a wireless network including a server and plurality of existing clients, by enabling a new client to join the network without the use of a separate reservation channel or period, the system comprising:

the server, including a radio for transmitting and receiving data over the wireless network, wherein the sewer and radio cooperate to control data transmission on the network and to organize data transmission in the wireless network into frames, wherein each frame includes a plurality of time slots, each of which is assigned to an existing client for transmissions between that client and the server, and wherein the server and radio provide a dedicated quiet period independent of the plurality of time slots during which the server and the existing clients do not transmit;

a plurality of clients, each including a radio for transmitting and receiving data over the wireless network, wherein each client receives data transmissions from the server during a first time slot assigned to that client, and transmits data to the server during a second time slot assigned to that client; and

a new client, including a radio for transmitting and receiving data over the wireless network, the new client monitoring data transmissions on the wireless network to detect the dedicated quiet period and transmitting data to the server during the detected quiet period;

wherein, a turn-around slot selectively inserted between the first and second time slots for selectively supporting half-duplex communications between the server and the plurality of existing clients.

12. The system of claim 11, wherein the server starts data frames at a rate corresponding to a video frame rate.

13. The system of claim 11, wherein all time slots for transmission from the server are grouped together and all time slots for transmission of data by the existing clients are grouped together.

14. The system of claim 13, wherein the time slots for data transmission by the server are of the same duration, and one or more time slots are assigned to each existing client based on the amount of data being sent to that client.

15. The system of claim 14, wherein the number of time slots assigned to an existing client is maintained for at least two successive data frames.

16. The system of claim 15, wherein the number of number of time slots assigned to an existing client is maintained for successive data frames until changed by the server.

17. The system of claim 13 wherein the time slots for data transmission are of the variable duration, and the length of a time slot assigned to each existing client is based on the amount of data being transmitted between the server and that client.

18. The system of claim 17, wherein the length of a time slot assigned to an existing client is maintained for at least two successive data frames.

19. The system of claim 17, wherein the length of a time slot assigned to an existing client is maintained far successive data frames until changed by the server.

20. The system of claim 11, wherein the length of the quiet period is approximately the same length as a time slot.