Communication network having a plurality of bridging nodes which transmit a beacon to terminal nodes in power saving state that it has messages awaiting delivery

• US 6,895,450 B2
• Filed: 04/16/2002
• Issued: 05/17/2005
• Est. Priority Date: 10/01/1991
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Meier, Robert C., Mahany, Ronald L., Luse, Ronald E.
• Primary Examiner(s): PEYTON, TAMMARA R
• Application Number:
  US10/123,873
• Publication Number:
  US 20030051080A1
• Time in Patent Office: 1,127 Days
• Field of Search: 710/18, 710/46, 709/227, 709/304, 713/320, 713/321, 713/323, 713/324, 455/342, 455/524, 455/517, 455/343, 375/132, 375/202, 375/220, 370/329, 370/351
• US Class Current: 710/18
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 15/0225 User interface arrangements, e.g. keyboard, display; Interfaces to other computer systems
• CPC Class Codes: G06K 7/1098 the scanning arrangement having a modular construction
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: H01Q 1/007 specially adapted for indoor communication
• CPC Class Codes: H01Q 1/241 used in mobile communications, e.g. GSM H01Q1/247, H01Q1/248 take precedence
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H04B 1/1615 Switching on; Switching off, e.g. remotely battery saving circuits associated with selective call operation H04W52/00; details of power consumption reduction in a PLL, H03L7/0802, H03L7/14, H03L2207/08, H03L2207/18; muting amplifiers by gain control see H03G3/34
• CPC Class Codes: H04B 1/3833 Hand-held transceivers
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 17/0085 using test signal generators
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0007 by modifying the frame length
• CPC Class Codes: H04L 1/0014 by adapting the source coding
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04L 45/00 : Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/04 : Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/44 : Distributed routing
• CPC Class Codes: H04L 45/48 : Routing tree calculation
• CPC Class Codes: H04L 45/488 : using root node determination
• CPC Class Codes: H04L 47/6225 : Fixed service order, e.g. Round Robin
• CPC Class Codes: H04L 49/90 : Buffering arrangements
• CPC Class Codes: H04L 49/9057 : Arrangements for supporting packet reassembly or resequencing
• CPC Class Codes: H04L 69/14 : Multichannel or multilink protocols
• CPC Class Codes: H04L 69/32 : Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
• CPC Class Codes: H04L 69/324 : in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 69/325 : in the network layer [OSI layer 3], e.g. X.25 H04L69/16 takes precedence
• CPC Class Codes: H04L 69/326 : in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 9/40 : Network security protocols
• CPC Class Codes: H04W 40/02 : Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 40/08 : based on transmission power
• CPC Class Codes: H04W 40/10 : based on available power or energy
• CPC Class Codes: H04W 40/246 : Connectivity information discovery
• CPC Class Codes: H04W 40/248 : Connectivity information update
• CPC Class Codes: H04W 40/26 : for hybrid routing by combining proactive and reactive routing
• CPC Class Codes: H04W 40/30 : for proactive routing
• CPC Class Codes: H04W 40/36 : due to handover
• CPC Class Codes: H04W 52/0225 : using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/029 : reducing the clock frequency of the controller
• CPC Class Codes: H04W 68/00 : User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 84/12 : WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/02 : Terminal devices
• CPC Class Codes: H04W 88/06 : adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/08 : Access point devices
• CPC Class Codes: H04W 88/14 : Backbone network devices
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

An apparatus and a method for routing data in a radio data communication system having one or more host computers, one or more intermediate base stations, and one or more RF terminals organizes the intermediate base stations into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Communication between the host computer and the RF terminals is achieved by using the network of intermediate base stations to transmit the data.

Claims

1. A multi-hop data communication network having RF capability comprising:

a plurality of terminal nodes; and

a plurality of bridging nodes which dynamically create and revise communication pathways between any two nodes in the network, each of the bridging nodes independently storing and maintaining local information that specifies how communication traffic should flow through that bridging node, and the plurality of bridging nodes, together, providing a complete specification for the communication pathways in the multi-hop communication network; and

said nodes using HELLO messages with a backward learning technique independently create and maintain locally stored information to specify how communication traffic should flow through that bridging node.

2. The multi-hop data communication system of claim 1 further comprising means for offsetting the time period between HELLO message broadcasts.

3. The multi-hop data communication system of claim 2 further comprising means for calculating the time period between HELLO message broadcasts to be received.

4. The multi-hop data communication system of claim 3 wherein said means for offsetting further comprising a first pseudo-random number generator for generating an offset.

5. The multi-hop data communication system of claim 4 wherein said means for calculating further comprising a second pseudo-random number generator used for computing the offset.

6. The multi-hop data communication system of claim 5 further comprising means for passing a seed value between said means for offsetting and said means for calculating so as to synchronize said first and second pseudo-random number generators.

7. A multi-hop data communication system having RF capability comprising:

a plurality of terminal nodes;

a plurality of bridging nodes; and

said bridging nodes further comprising, means for maintaining communication pathways between any two nodes in the network by repeatedly broadcasting messages identifying itself, means for determining the timing between the identifying message broadcasts.

8. The multi-hop data communication system of claim 7 wherein said terminal nodes further comprising means for calculating the time period between HELLO message broadcasts to be received.

9. The multi-hop data communication system of claim 8 wherein the means for determining the timing and the means for calculating the time both further comprise pseudo-random number generator using a common seed value.

10. The multi-hop data communication system of claim 9 further comprising means for passing a seed value between said means for determining the timing and the means for calculating the time.

11. In a multi-hop data communication network having a plurality of bridging nodes and RF communication capability, a plurality of terminal nodes comprising:

a RF transceiver;

means for segmenting digitally encoded data to be transferred into discrete data packets;

means responsive to said segmenting means for individually transmitting each discrete data packet; and

means for reconstructing discrete data packets into digitally encoded data.

12. The multi-hop data communication network of claim 11 wherein said terminal nodes further comprise means for digitally encoding voice signals, and means for generating audio signals from digitally encoded voice signals.

13. The multi-hop data communication network of claim 11 wherein the length of said discrete data packets are chosen based on correlation distance.

14. The multi-hop data communication network of claim 12 wherein the length of said discrete data packets are chosen based on correlation distance.

15. A communication network comprising:

a plurality of terminal nodes;

a plurality of bridging nodes which, together, form a spanning tree that specifies wireless communication pathways for relaying messages between said plurality of terminal nodes;

one of said plurality of terminal nodes selectively enters or exits a sleep mode through direct, wireless communication with one of said plurality of bridging nodes;

the one of said plurality of bridging nodes attempts to forward messages to the one of said plurality of terminal nodes when the one of said plurality of terminal nodes is not in the sleep mode;

the one of said plurality of bridging nodes stores messages destined for the one of said plurality of terminal nodes when the one of said plurality of terminal nodes is in the sleep mode; and

the one of said plurality of bridging nodes forwards stored messages to the one of said plurality of terminal nodes operating in the sleep mode upon request from the one of said plurality of terminal nodes.

16. The communication network of claim 15 further comprising means within the one of said plurality of bridging nodes for determining whether the one of said plurality of terminal nodes has been disconnected from the network.

17. The communication network of claim 16 wherein the determining means considers whether the one of said plurality of terminal nodes is in the sleep mode in making a determination of disconnection.

18. The communication network of claim 15 wherein the one of said plurality of terminal nodes comprises a receiver, and the one of said plurality of terminal nodes, when in the sleep mode, enters a power saving state that disables the receiver.

19. The communication network of claim 18 wherein the power saving state is entered for a period of time after which the one of said plurality of terminal nodes reactivates the receiver to receive communication from the one of said plurality of bridging nodes.

20. The communication network of claim 19 wherein the period of time is of such length as to permit the one of said plurality of terminal nodes to maintain time synchronization with communications from the one of said plurality of bridging nodes.

21. A wireless communication network comprising:

a plurality of terminal nodes;

a plurality of bridging nodes which, together, form a spanning tree that specifies wireless communication pathways for forwarding messages between said plurality of terminal nodes;

each of said plurality of terminals selectively enters or exits a sleep mode through communication with at least one of said plurality of bridging nodes; and

said plurality of bridging nodes forward messages to those of said plurality of terminal nodes that are in the sleep mode only upon request, and immediately attempt to forward messages to those of said plurality of terminal nodes that are not in the sleep mode.

22. The communication network of claim 21 further comprising means within said plurality of bridging nodes for determining whether any of said plurality of terminal nodes has been disconnected from the network.

23. The communication network of claim 22 wherein the determining means considers whether said plurality of terminal nodes are in the sleep mode in making a determination of disconnection.

24. The communication network of claim 21 wherein each of said plurality of terminal nodes comprises a receiver, and each of said plurality of terminal nodes, when in the sleep mode, enters a power saving state that disables the receiver.

25. The communication network of claim 24 wherein the power saving state is entered for a period of time after which each of said plurality of terminal nodes reactivates the receiver to receive communications from said plurality of bridging nodes.

26. The communication network of claim 25 wherein the period of time is of such length as to permit said plurality of terminal nodes to maintain time synchronization with communications from said plurality of bridging nodes.

27. A communication network supporting wireless communication throughout an area comprising:

a plurality of roaming terminal nodes;

a plurality of bridging nodes which, together, form wireless communication pathways for relaying messages between said roaming terminal nodes;

each of the plurality of bridging nodes transmits at predetermined intervals hello messages that indicated the presence of pending messages; and

each of the plurality of roaming terminal nodes comprising a controller and a wireless receiver, wherein the controller synchronizes use of the wireless receiver at the predetermined intervals to receive the hello messages transmissions.

28. The communication network of claim 27 wherein the plurality of roaming terminal nodes operate under limited battery power in a low power consumption state by disabling the wireless receiver;

and each of the plurality of roaming terminal nodes enables the wireless receiver at the predetermined intervals to receive hello message transmissions.

29. The communication network of claim 28 wherein the plurality of roaming terminal nodes leave the lower power consumption state to receive pending messages.