Method and apparatus for coordinating a wireless PAN network and a wireless LAN network

• US 20060215601A1
• Filed: 03/14/2006
• Published: 09/28/2006
• Est. Priority Date: 03/14/2005
• Status: Abandoned Application

• Current Assignee: Atmel Wi-Fi Solutions, Inc. (Microchip Technology Incorporated)
• Original Assignee: Ozmo, Inc. (Microchip Technology Incorporated)
• Inventors: Vleugels, Katelijn, Peeters, Roel
• Application Number:
  US11/376,737
• Publication Number:
  US 20060215601A1
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 52/0209 in terminal devices terminal devices per se H04W88/02
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 84/10 Small scale networks; Flat hierarchical networks
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: H04W 84/22 with access to wired networks
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• 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 88/10 adapted for operation in multiple networks, e.g. multi-mode access points
• CPC Class Codes: H04W 92/02 Inter-networking arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Devices of a personal area network (PAN) use a wireless medium that is shared with a wireless local area network (WLAN). WLAN devices communicate using protocols of the WLAN and PAN devices communicate using PAN protocols allowing for lower power transmissions over the wireless medium relative to transmissions over the WLAN. A PAN coordinator device obtains access to the wireless medium for the PAN devices by signalling a reservation of the medium by the PAN coordinator device, such that the other devices defer use of the wireless medium, including at least one WLAN device, for a reservation period. During the reservation period, the communication is done using the PAN protocol. The signalling can be implicit in that the PAN coordinator device transmits one or more frame using the PAN protocol but that is at least partially understandable by WLAN devices such that they defer upon receipt of one or more of the PAN protocol frames, which may be a standard or modified HCCA-CF poll frame, a CTS frame with an increased duration field, or other variation. A PAN coordinator might also signal an access point to set up a DLS link between the PAN coordinator and itself and use the DLS period for PAN traffic.

Claims

1. A method of communicating between devices of a personal area network (PAN) using a wireless medium that is shared with a wireless local area network (WLAN), wherein WLAN devices communicate using protocols of the WLAN and PAN devices communicate using PAN protocols allowing for lower power transmissions over the wireless medium relative to transmissions over the WLAN, the method comprising:

obtaining access to the wireless medium for a PAN coordinator device, wherein transmission access to the wireless medium is allocated to the PAN coordinator device to allow it to transmit while other devices defer;

signalling a reservation of the medium by the PAN coordinator device, such that the other devices defer use of the wireless medium, including at least one WLAN device, for a reservation period; and

communicating between the PAN coordinator device and a PAN device over the wireless medium during the reservation period, wherein communication is done using the PAN protocol.

2. The method of claim 1, wherein signalling a reservation of the medium is implicit in that the PAN coordinator device transmits one or more frame using the PAN protocol but that is at least partially understandable by WLAN devices such that they defer upon receipt of one or more of the PAN protocol frames.

3. The method of claim 2, wherein the one or more frame using the PAN protocol comprises a frame directed to a PAN device having an increased duration field.

4. The method of claim 3, wherein the WLAN network is an 802.11x network and one or more frame using the PAN protocol comprises an 802.11x frame of type “

data”

, or a modification thereof, directed to a PAN device and having an increased duration field.

5. The method of claim 3, wherein the one or more frame using the PAN protocol comprises an 802.11x CTS frame with an increased duration field.

6. The method of claim 3, wherein the one or more frame using the PAN protocol comprises an 802.11x frame or modification thereof, transmitted using a highest priority queue.

7. The method of claim 3, wherein the one or more frame using the PAN protocol comprises an HCCA-CF poll frame having a plurality of subtype fields including a “

data”

subtype field and a “

poll”

subtype field, wherein the HCCA-CF poll frame is sent with its “

data”

subtype field cleared and its “

poll”

subtype field set.

8. The method of claim 3, wherein the one or more frame using the PAN protocol comprises a modified HCCA-CF poll frame only partially compliant with a WLAN standard, the modified HCCA-CF poll frame having a plurality of subtype fields including a “

data”

subtype field and a “

poll”

subtype field, wherein the HCCA-CF poll frame is sent with its “

data”

subtype field cleared and its “

poll”

subtype field set.

9. The method of claim 3, wherein the PAN protocol frame includes data addressed to a PAN device.

10. The method of claim 3, wherein the one or more frame using the PAN protocol comprises an HCCA-CF poll frame having a plurality of subtype fields including a “

to DS”

subtype field and a “

from DS”

subtype field, wherein the HCCA-CF poll frame is sent with both subtype fields cleared, thereby distinguishing from a valid WLAN frame.

11. The method of claim 3, wherein the PAN protocol frame is transmitted using a highest priority queue.

12. The method of claim 1, wherein signalling a reservation of the medium is explicit in that the PAN coordinator device transmits one or more frame using the WLAN protocol to signal WLAN devices, wherein the one or more frame signals a reservation of the wireless medium using WLAN protocol frames for that purpose.

13. The method of claim 12, wherein signaling to WLAN devices using WLAN protocol frames occurs prior to each communication event with a PAN device.

14. The method of claim 12, wherein signaling to WLAN devices using WLAN protocol occurs once for the start of a series of SWN communication events.

15. The method of claim 12, wherein the one or more frame using the WLAN protocol to signal WLAN devices comprises an HCCA frame to set up a traffic stream for the PAN coordinator device, the method further comprising using the agreed on timeslots to communicate with a PAN device.

16. The method of claim 12, wherein the one or more frame using the WLAN protocol comprises a CTS frame with an increased duration field.

17. The method of claim 1, wherein:

signalling a reservation of the medium by the PAN coordinator device comprises signalling a reservation of the medium for a plurality of PAN devices; and

communicating between the PAN coordinator device and a PAN device over the wireless medium comprises communicating between the PAN coordinator device and each of a plurality of PAN devices.

18. The method of claim 17, further comprising sending a frame from the PAN coordinator device to two or more of the plurality of PAN devices with an indication of time offsets for each of the two or more PAN devices indicating a scheduled time for the PAN device to respond to the frame.

19. The method of claim 17, further comprising sending a frame from the PAN coordinator device to two or more of the plurality of PAN devices with an indication of the two or more PAN devices expected to respond to the frame.

20. A wireless network interface circuit adapted to be coupled to a wireless network for communicating, the wireless network interface circuit comprising:

circuitry for conveying signals between the network interface circuit and a computing device to which the network interface circuit is electrically coupled;

logic for determining a length of time for PAN-computing device communication; and

logic for reserving the wireless medium for the length of time by signalling from the network interface circuit using a protocol of a PAN network, wherein the PAN network protocol is adapted such that devices operable in a second network will defer use of a shared wireless medium even without being able to completely interpret frames sent from the network interface circuit according to the PAN network protocol

logic for wirelessly communicating with a PAN device using the wireless medium and the PAN network protocol during the time, thereby allowing communication between the wireless network interface circuit and the PAN device without traffic expected from the second network.

21. A wireless network interface circuit adapted to be coupled to a wireless network for communicating, the wireless network interface circuit comprising:

circuitry for conveying signals between the network interface circuit and a computing device to which the network interface circuit is electrically coupled;

logic for wirelessly communicating with a network coordinator of a first network;

logic for wirelessly communicating with a node of a second network, wherein an effective broadcast range of the node of the second network is expected to be insufficient to communicate directly with the network coordinator of the first network;

logic for determining a length of time for PAN-computing device communication; and

logic for reserving the wireless medium with the network coordinator of the first network for the length of time, thereby allowing communication from the node without traffic expected from the network coordinator of the first network.

22. A method of interfacing a computing device to a wireless local area network (WLAN) and a wireless personal area network (PAN), wherein the WLAN is characterized by a plurality of nodes intercommunicating over a wireless medium and the wireless PAN is characterized by lower power transmissions over a wireless medium relative to transmissions over the WLAN, the method comprising:

adapting a network circuit, comprising logic and at least one antenna, for interfacing the computing device to the WLAN and to the wireless PAN;

setting up associations and communicating with devices over the WLAN and the wireless PAN using at least one common modulation scheme and at least one common frame formatting layer; and

coordinating with the WLAN coordinator and the wireless PAN device, usage of the WLAN such that the wireless PAN device and computing device can communicate without interference.

23. The method of claim 22, wherein the network circuit is configured to go into a power-save mode and to communicate to the access point device that it is entering the power-save mode, the method further comprising:

exiting the power-save mode to handle secondary network traffic while not informing the access point device of the wake-up, thereby reducing a chance that the access point will attempt to communicate with the network circuit while it is handling the secondary network traffic.

24. The method of claim 22, wherein the common modulation scheme is at least in part compliant with an 802.11x PHY layer specification, the common frame formatting layer is at least in part compliant with an 802.11x MAC layer specification and coordination with the WLAN coordinator and the wireless PAN device comprises reserving the wireless medium for a length of time for PAN-computing device communication.

25. The method of claim 22, further comprising:

determining an inactivity time;

communicating between the wireless PAN device and the computing device as needed to agree on the value of the inactivity time; and

disabling at least a part of a coordination function of the computing device following a start of the inactivity time, wherein disabling is such that less power per unit time is consumed by the network circuit relative to power consumed when not disabled.

26. A method of interacting with a primary network and a secondary network, wherein a plurality of wireless local area network (WLAN) devices communicate using protocols of the primary network and a wireless medium and wherein one or more personal area network (PAN) devices communicate using the protocols of the secondary network and the wireless medium using lower power transmissions over the wireless medium relative to transmissions over the WLAN, the method comprising:

configuring a dual-net device that is capable of communicating over the primary network using its protocols and over the secondary network using its protocols;

determining, at the dual-net device, that a reservation of the wireless medium is needed for a PAN device that is not also a dual-net device;

signalling a request for a reservation of the wireless medium from the dual-net device such that the request can be received and understood by at least one other WLAN device;

determining, at the dual-net device, if the reservation was successful;

if the reservation was successful, signalling, using the protocols of the secondary network, to the PAN device that is not also a dual-net device that the wireless medium is reserved for that device for communications using the protocols of the secondary network.

27. The method of claim 26, wherein the primary network is an 802.11x WLAN and the secondary network is an overlay network wherein protocols of the overlay network are only partially compliant with the protocols of the primary network.

28. The method of claim 26, wherein the plurality of WLAN devices includes at least one access point.

29. The method of claim 26, wherein signalling the reservation request comprises signalling the reservation request using the protocols of the secondary network, wherein the protocols of the secondary network are such that frames transmitted according to those protocols are sufficiently compliant with the protocols of the primary network such that the reservation request can be received and understood by at least one other WLAN device.

30. The method of claim 26, wherein signalling the reservation request comprises signalling the reservation request using the protocols of the primary network.

31. The method of claim 30, wherein the reservation request comprises setting up a traffic stream with the primary network and having an access point grant a transmission opportunity for transmissions between the dual-net device and the access point, then using that transmission opportunity for communicating with PAN devices of the secondary network.

32. The method of claim 26, wherein signalling the reservation request comprises signalling the reservation request within a reduced radius selected such that at least one of the WLAN devices would not hear the reservation request, thereby allowing for continued use of the wireless medium by WLAN devices outside the reduced radius while the dual-net device and/or PAN devices inside the reduced radius use the wireless medium.

33. The method of claim 32, wherein the dual-net device adjusts its reservation request to vary the radius within which the request is likely to be correctly received and the adjustment is based on common wireless networking space activity.

34. The method of claim 32, wherein the dual-net device adjusts its reservation request to vary the radius within which the request is likely to be correctly received and the adjustment is based on present activity in one or more of the primary network or a second secondary network.

35. The method of claim 37, the dual-net device determines the present activity at least in part by requesting activity information from an access point with which the dual-net device is associated in the primary network.

36. The method of claim 26, wherein the dual-net device adjusts its reservation request based on present or future activity in the primary network determined at least in part by requesting activity and/or scheduling information from an access point with which the dual-net device is associated in the primary network.

37. The method of claim 36, wherein the dual-net device is further configured to coordinate and time secondary network traffic during periods of expected inactivity in the primary network as the dual-net device determines from activity and/or scheduling information.

38. The method of claim 37, wherein the activity and/or scheduling information includes information about the access point'"'"'s Controlled Access Phase (CAP).

39. The method of claim 26, wherein determining, at the dual-net device, if the reservation was successful comprises sending a poll frame with an increased duration field to reserve the wireless medium.

40. A method of communicating in a wireless network between a device as a station and an access point over a first network and between the device as a coordinator and a peripheral over a second network, comprising:

communicating with the access point over the first wireless network being an 802.11x network;

communicating with the peripheral over the second wireless network, wherein the second wireless network operates using protocols are only partially compliant with protocols of the first wireless network;

transmitting a first frame transmitted by the coordinator with increased duration field, thereby reserving a wireless medium for transmissions in the second network.

41. The method of claim 40, further comprising transmitting an HCCA-CF poll frame addressed to the peripheral with the duration field increased, with a subtype field “

data”

cleared and a subtype field “

poll”

set.

42. The method of claim 40, further comprising transmitting an HCCA-CF poll frame addressed to the peripheral with the duration field increased, with the subtype fields “

data” and

“

poll”

both set and including data in this frame addressed to the peripheral.

43. The method of claim 40, further comprising transmitting an HCCA-CF poll frame addressed to the peripheral using a medium access scheme regularly used by non-AP STAs.

44. The method of claim 43, further comprising transmitting the HCCA-CF poll using a highest priority queue.

45. A method of communicating in a wireless network between a device as a station and an access point over a first network and between the device as a coordinator and a peripheral over a second network, comprising:

communicating with the access point over the first wireless network, wherein the first wireless network is an 802.11x network;

signalling, from the device to the access point, for the use of DLS, DLS being a protocol that allows for two stations associated with the access point to communicate directly; and

signalling, from the device to a second device, using DLS, wherein the second device is not a device associated with the access point.

46. The method of claim 45, further comprising associating the device with the access point as a second associated device to cover traffic between the device and the second device.