Scalable wireless network topology systems and methods

• US 6,728,514 B2
• Filed: 12/13/2000
• Issued: 04/27/2004
• Est. Priority Date: 09/08/2000
• Status: Expired due to Fees

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Wi-LAN Inc.
• Inventors: Poulsen, Lars, Bandeira, Nuno
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Miller, Brandon J
• Application Number:
  US09/736,642
• Publication Number:
  US 20020072329A1
• Time in Patent Office: 1,231 Days
• Field of Search: 455/305, 455/306, 455/423-425, 455/446, 455/457, 455/63, 455/11.1, 455/25, 455/13.1, 455/428-429
• US Class Current: 455/13.1
• CPC Class Codes: H04B 7/2609 Arrangements for range control, e.g. by using remote antennas
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

Wireless broadband data access is provided to and from a plurality of locations distributed randomly over a large geographic area. The network can be deployed one node at a time, with a new node incorporated into the network if within radio frequency range of any existing node in the network. The newly incorporated node can then be the attaching point for another new node that requires incorporation into the network. Data can be forwarded over multiple hops to reach its destination in the network, with the data-polling scheme self-synchronizing with minimal transmission overhead.

Claims

1. A wireless communications network comprising:

a plurality of locations;

a transceiver coupled to each of the locations and adapted to transmit or receive a radio frequency signal by selecting a channel from at least two non-conflicting channels, the transceiver further adapted to connect to two distinct antennas;

wherein one of the locations is designated a root node and the other locations are designated as non-root nodes, with each non-root node within radio frequency range of either the root node or another non-root node and forming a tree structure originating at the root node and branching out from the root node to one or more of the non-root nodes, the locations not within radio frequency range of the root node communicating with the root node through non-root nodes that function as repeaters, with the repeaters designated as parents and the non-root nodes that communicate with the repeaters designated as children for each level of the tree structure;

a broadbeam antenna coupled to the transceiver of the root node to transmit or receive wireless communications with the non-root nodes that are within radio frequency range of the root node; and

a directional antenna coupled to the transceivers of the non-root nodes that are within radio frequency range of the root node to transmit or receive wireless communications with the root node.

2. The network of claim 1, further comprising:

a broadbeam antenna connected to each transceiver of a parent to transmit or receive wireless communications with its children; and

a directional antenna connected to each transceiver of a child to transmit or receive wireless communications with its parent.

3. The network of claim 2, wherein the broadbeam antennas further comprise an omnidirectional antenna or a sector antenna.

4. The network of claim 1, wherein the wireless communications flows either upstream towards the root node or downstream away from the root node relative to the tree structure.

5. The network of claim 1, wherein the broadbeam antenna or the directional antenna is polarized.

6. The network of claim 2, further comprising the addition of a new node by forming appropriate parent-child relationships with one of the locations.

7. The network of claim 1, wherein the wireless communications further comprise variable length packets.

8. The network of claim 1, wherein the wireless communications directed away from the root node utilize a first channel and the wireless communications directed towards the root node utilize a second channel that does not conflict with the first channel.

9. The network of claim 1, wherein each of the locations further comprises an interface couplable with another network.

10. The network of claim 6, further comprising a network identification that is identical for each of the transceivers and a source address that is unique for each of the transceivers in the wireless communications network.

11. The network of claim 1, wherein the transceiver further comprises a control module to execute a polling scheme for managing the wireless communications between the locations, the locations having a master-slave node relationship, with the master node upstream of the slave node that must communicate through the master node to transmit data upstream one level towards the root node in the tree structure, the polling scheme comprising:

transmitting, from the master node to the slave node, a poll message;

transmitting, from the slave node to the master node, inbound data or a poll acknowledge message; and

transmitting, from the master node to the slave node, outbound data.

12. The network of claim 11, wherein a slave node, upon completion of the polling scheme with its master node, becomes a master node to poll its slave nodes prior to reverting back to being a slave node.

13. The network of claim 11, wherein the polling scheme further comprises switching to the next slave node and beginning the polling scheme immediately after a timeout period when the inbound data or the poll acknowledge message is not received from the current slave node.

14. The network of claim 11, wherein the poll message further comprises new RF link parameters to change the transmission parameters of the slave node or the poll acknowledge message further comprises new RF link parameters to change the transmission parameters of the master node.

15. The network of claim 11, wherein the control module further executes a new node polling scheme to incorporate a new location into the network, the new location within radio frequency range of the root node or a non-root node that functions as the master node to the new location, the new node polling scheme comprising:

transmitting, from the master node to the new location, a new node poll message;

transmitting, from the new location to the master node, an attach request message; and

transmitting, from the master node to the new location, an attach request acknowledge message.

16. The network of claim 15, wherein the attach request message further comprises optimal radio frequency link parameters for transmissions from the master node to the new location, and the attach request acknowledge message further comprises optimal radio frequency link parameters for transmissions from the new location to the master node.

17. The network of claim 15, further comprising transmitting, from the master node to the new location, an attach request denied message, instead of the attach request acknowledge message, if the network ID transmitted from the new location is not valid.

18. The network of claim 11, wherein the control module further comprises:

a central processor unit; and

a memory, connected to the central processor unit, that stores instructions for causing the central processor unit to execute the polling scheme.

19. A wireless communications network comprising:

a root node;

a broadbeam antenna coupled to the root node;

at least one non-root node;

a directional antenna coupled to each of the non-root nodes and directed at the broadbeam antenna of the root node to exchange wireless communications with the root node, wherein at least one of said non-root nodes functions as a repeater node, with the repeater node further having a broadbeam antenna;

at least one child node of the repeater node; and

a directional antenna coupled to each of the child nodes of the repeater node and directed at the broadbeam antenna of the repeater node to exchange wireless communications with the repeater node, wherein the broadbeam antennas in the network are adapted to provide wireless communications with downstream nodes in the network and the directional antennas in the network are adapted to provide wireless communications with upstream nodes in the network.

20. The network of claim 19, wherein transmissions of the wireless communications to downstream nodes are adapted to use a first channel and the transmissions of the wireless communications to upstream nodes are adapted to use a second channel.

21. The network of claim 20, wherein the first channel and the second channel are separated in frequency, or by codes of a code division multiple access scheme.

22. The network of claim 19, wherein the wireless communications further comprises a downstream data poll message, followed by upstream data, followed by downstream data between respective nodes.

23. The network of claim 19, wherein the root node, the non-root nodes, and the child nodes each further comprises a transceiver adapted to provide half-duplex operation, the transceiver comprising:

a transmit path comprising a low noise amplifier, a downconverter, and a demodulator;

a receive path comprising a modulator, an upconverter, and an amplifier;

a control system connected to the transmit path and the receive path and adapted to provide a baseband signal to the transmit path and adapted to receive a baseband signal from the receive path, the control system determining frequencies of mixing signals provided to the downconverter, the demodulator, the modulator, and the upconverter;

a first switch adapted to connect to the transmit path or the receive path, the first switch controlled by the control system; and

a second switch connected to the first switch and controlled by the control system, the second switch adapted to connect to the directional antenna or the broadbeam antenna.

24. The network of claim 19, wherein at least one of the root node, the non-root node, and the child node further comprises a host interface adapted to couple to a second network.

25. The network of claim 19, wherein the wireless communications network is self-synchronized, with the root node exchanging wireless communications with each of the non-root nodes in a consecutive polling fashion and each of the non-root nodes that function as repeaters polling their child nodes in a consecutive polling fashion immediately after the corresponding non-root node is polled by the root node.

26. The network of claim 19, wherein the network can be segmented into more than one network by designating one of the repeater nodes as a second root node and terminating the wireless communications between the repeater node and the root node.

27. A method of communicating in a wireless communications network, the network comprised of a root node and at least one repeater node and at least one leaf node which forms a tree structure having a master-slave relationship at each level of the tree structure, the root node having an antenna for wireless communication with its slaves, the repeater nodes and the leaf nodes each having only one master and having a directional antenna pointed at the respective master, the repeater nodes having an additional antenna for wireless communication with their slaves for when the repeater nodes are functioning as masters, the method performed by each root, repeater, and leaf node comprising:

determining the node type;

performing a master cycle repeatedly if the node is the root node;

performing an attach cycle if unattached or becomes detached from the network and if the node is not the root node; and

performing a slave cycle followed the master cycle repeatedly, if the node is not the root node.

28. The method of claim 27, wherein the master cycle further comprises:

transmitting from the master a new node poll;

transmitting from the master an attach request acknowledge if a valid attach request is received from a new slave;

transmitting to a slave a data poll message; and

receiving data or a message from the slave.

29. The method of claim 28, wherein the master cycle further comprises transmitting from the master an attach request denied if an invalid network identification is received from a new slave.

30. The method of claim 28, further comprising transmitting data or a message to the slave.

31. The method of claim 27, wherein the attach cycle further comprises:

receiving a new node poll message from a master attached to the network;

transmitting to the master an attach request message; and

receiving an attach request acknowledge from the master.

32. The method of claim 31, wherein the attach request message further comprises optimal radio frequency link parameters for transmission from the master to the slave.

33. The method of claim 31, further comprising setting a response probability equal to one and decreasing by one-half for each failed attach request message.

34. The method of claim 27, wherein the slave cycle further comprises:

receiving a data poll message from the master;

transmitting data to the master; and

receiving data from the master.