Radio frequency local area network

• US 6,400,702 B1
• Filed: 03/21/2000
• Issued: 06/04/2002
• Est. Priority Date: 10/01/1991
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Inventors: Meier, Robert C.
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US09/531,880
• Time in Patent Office: 805 Days
• Field of Search: 370/256, 370/278, 370/282, 370/285, 370/338, 370/401, 370/402, 370/403, 370/404, 370/405, 370/406, 370/407, 370/408, 370/411, 370/437, 370/465, 370/466, 370/349, 370/328
• US Class Current: 370/338
• 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: 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 1/3833 Hand-held transceivers
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• 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 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 69/323 : in the physical layer [OSI layer 1]
• 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 40/22 : using selective relaying for reaching a BTS [Base Transceiver Station] or an access point
• CPC Class Codes: H04W 40/246 : Connectivity information discovery
• CPC Class Codes: H04W 40/28 : for reactive routing
• CPC Class Codes: H04W 40/30 : for proactive routing
• CPC Class Codes: H04W 40/36 : due to handover
• CPC Class Codes: H04W 8/26 : Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/04 : Large scale networks; Deep hierarchical networks
• CPC Class Codes: H04W 84/12 : WLAN [Wireless Local Area Networks]
• 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: H04W 92/20 : between access points

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 communication network for exchanging communication packets between a plurality of network computing devices, said communication network comprising:

a first subnet;

a plurality of intermediate wireless access points utilizing routing tables indexed by address entries to provide wireless routing pathways with the communication network;

a first wired access point connected both directly to said first subnet and wirelessly to at least one of said plurality of intermediate wireless access points, said first wired access point utilizing a first forwarding table indexed by address entries to provide bridging between said first subnet and said plurality of intermediate wireless access points; and

said first wired access point and said plurality of intermediate wireless access points, together, forming a spanning tree to communicatively couple network computing devices.

2. The communication network of claim 1 further comprising:

a second subnet;

a second wired access point connected both directly to said second subnet and wirelessly to at least one of said plurality of intermediate wireless access points, said second wired access point utilizing a second forwarding table indicated by address entries to provide bridging between said second subnet and said plurality of intermediate wireless access points; and

said second wired access point participating with said first wired access point and said plurality of intermediate wireless access points in the spanning tree.

3. The communication network of claim 2 wherein each of said plurality of network computing devices having a unique address, and said first and second wired access points and said plurality of intermediate wireless access points selectively providing communication connectivity among said plurality of network computing devices through reference to the unique address identified in each communication packet.

4. The communication network of claim 2 wherein said network computing devices comprise a plurality of terminal nodes which utilize said first and second wired access points and said plurality of intermediate wireless access points for network communication.

5. The communication network of claim 2 wherein said network computing devices further comprising a first remote station, attached to the first subnet, having a first address and a second remote station, attached to the second subnet, having a second address;

and wherein said first and second wired access points and said plurality of intermediate wireless access points providing communication connectivity between said first and second remote stations with reference to the first or second address associated with each communication packet.

6. The communication network of claim 3 wherein at least one of said network computing devices communicates wirelessly to one of said plurality of intermediate wireless access points, and at least one of said network computing devices communicates directly via said first subnet.

7. A communication network for exchanging communication packets that have addresses identified therein, said communication network comprising:

a first subnet;

a plurality of computing devices each of which having a unique address;

a plurality of access points utilizing tables indexed by addresses to deliver communication packets along pathways between said plurality of computing devices;

each of said plurality of access points providing wireless communication with select others of said plurality of access points;

at least one of said plurality of access points providing direct, hard-wired communication to said first subnet; and

said plurality of access points dynamically arranging and rearranging the pathways to maintain efficient delivery of communication packets among said plurality of computing devices.

8. The communication network of claim 7 wherein said plurality of computing devices comprising:

at least one mobile terminal that wirelessly communicates with said plurality of access points; and

at least one stationary computer directly attached to said first subnet.

9. The communication network of claim 8 further comprising:

a second subnet;

at least one of said plurality of access points providing direct, hard-wired communication to said second subnet; and

at least one of said plurality of computing devices directly attached to said second subnet.

10. The communication network of claim 7 wherein said plurality of access points utilize routing and bridging tables indexed by address entries to maintain communication pathways within the communication network.

11. The communication network of claim 7 wherein said plurality of access points utilize spanning tree routing tables indexed by addresses to wirelessly route communication packets between said plurality of computing devices.

12. The communication network of claim 9 wherein said plurality of access points utilize spanning tree routing tables indexed by addresses to wirelessly route communication packets between said plurality of computing devices.

13. A communication network for exchanging communication packets, each communication packet having a destination field for storing an address of a destination device, comprising;

a first wired subnet; and

a second wired subnet;

a plurality of computing devices, each of said plurality of computing devices having a unique address associated with the said first and second wired subnets;

a plurality of access points utilizing tables indexed by the unique addresses of said plurality of computing devices, said tables providing pathway information for delivering communication packets to said plurality of computing devices;

each of said plurality of computing devices constructs communication packets with the destination field containing the unique address of a selected other of said plurality of computing devices;

each of said plurality of access points providing wireless communication with select others of said plurality of access points;

said plurality of access points comprising first and second wired access points providing direct, hard-wired communication to said first wired subnet and said second wired subnet, respectively; and

said plurality of access points comprising said first wired access point and said second wired access point dynamically arranging and rearranging the pathway information in said tables to maintain efficient delivery of communication packets among said plurality of computing devices.

14. The communication network of claim 13 wherein at least one of said plurality of computing devices using a direct, serial communication link to exchange communication through said first wired subnet.

15. The communication network of claim 13 wherein said plurality of access points utilize spanning tree routing tables indexed by addresses to wirelessly route communication packets between said plurality of computing devices.

16. The communication network of claim 13 said plurality of computing devices comprising:

at least one mobile terminal that wirelessly communicates with at least one of said plurality of access points; and

at least one computing device that communicates using a hard-wired link to the first wired subnet.

17. The communication network of claim 13 further comprising:

at least one of said plurality of computing devices directly attached to said second wired subnet.

18. The communication network of claim 17 wherein at least one of said plurality of computing devices comprising a mobile terminal that wirelessly communicates via at least one of said plurality of access points.

19. The communication network of claim 13 wherein said first wired subnet comprises a wired link, and said unique addresses associated with said first wired subnet comprise unique addresses associated with said wired link.

20. A communication network for exchanging communication packets, each communication packet having a destination field for storing an address of a destination device, comprising:

at least three wired subnets;

a plurality of terminal devices, each of said plurality of terminal devices having a unique address associated with said at least three wired subnets;

a plurality of access points utilizing tables indexed by the unique addresses of said plurality of terminal devices, said tables providing information for delivering communication packets to said plurality of terminal devices;

each of said plurality of terminal devices constructs communication packets with the destination field containing the unique address of a selected other of said plurality of terminal devices;

each of said plurality of access points providing wireless communication with at least one of the other of said plurality of access points;

for each of said at least three wired subnets, at least one of said plurality of access points providing direct, hard-wired communication thereto; and

said plurality of access points providing communication pathways for exchanging communication packets between said plurality of terminal devices.

21. The communication network of claim 20 wherein said plurality of access points utilize spanning tree routing tables indexed by said unique addresses to route and bridge communication packets between said plurality of terminal devices.

22. The communication network of claim 21 said plurality of terminal devices comprising at least one mobile terminal that wirelessly communicates via at least one of said plurality of access points.

23. The communication network of claim 20 wherein said at least three wired subnets comprising wired links, and said unique addresses associated with said at least three wired subnets comprise unique addresses associated with said wired links.

24. The communication network of claim 20 wherein at least one of said plurality of terminal devices using a direct, serial communication link to exchange communication with one of said at least three wired subnets.