Mechanism to avoid interference and improve communication latency in mmWave WPANs

• US 8,149,806 B2
• Filed: 10/16/2008
• Issued: 04/03/2012
• Est. Priority Date: 03/11/2008
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Kesselman, Alex, Bachrach, Yuval
• Primary Examiner(s): Ly, Anh-Vu
• Application Number:
  US12/252,607
• Publication Number:
  US 20090232105A1
• Time in Patent Office: 1,265 Days
• Field of Search: None
• US Class Current: 370/338
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H04B 7/0682 using phase diversity (e.g. phase sweeping)
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Briefly, a mechanism to avoid interference and improve channel efficiency in mmWave Wireless Personal Area Networks (WPANs) is disclosed. In particular, interference information during various time periods is tracked and used to optimize transmission scheduling. Further, a mechanism is provided to improve communication latency by distributing responsibility for coordination of slots amongst multiple transmitting devices.

Claims

1. A method for transmissions in a wireless personal area network (WPAN), the WPAN operating pursuant to standards of a WPAN standardization body, the method comprising:

registering one or more transmission flows, wherein a transmission flow comprises a transfer of data from a transmitting device of the WPAN to a receiving device of the WPAN;

receiving by a coordinator of the WPAN a bandwidth request for at least one of the one or more transmission flows;

scheduling by the coordinator of the WPAN the at least one of the one or more transmission flows to a time slot in a super-frame;

receiving by the coordinator of the WPAN an interference report from one or more devices of the WPAN; and

generating by the coordinator of the WPAN a transmission schedule for a subsequent super-frame based on the interference report from the one or more devices of the WPAN;

wherein the scheduling comprises scheduling by the coordinator of the WPAN a plurality of transmission flows in time slots of the super-frame;

the generating comprises generating by the coordinator of the WPAN a transmission schedule for a subsequent super-frame based on the interference report from the one or more devices of the WPAN, wherein the same plurality of transmission flows are scheduled in the subsequent super-frame as in the super-frame, and the order of the transmission flows in the subsequent super-frame is changed from the order of the transmission flows in the super-frame, the change in order to reduce interference.

2. The method as recited in claim 1, wherein the scheduling comprises assigning two or more flows to a same time slot, wherein the two or more flows are a bidirectional flow, comprising a transmission from a first device of the WPAN to a second device of the WPAN and a transmission from the second device of the WPAN to the first device of the WPAN.

3. The method as recited in claim 2, wherein:

the scheduling comprises assigning by the coordinator of the WPAN a primary flow to a time slot; and

the method further comprises;

a transmitter of the primary flow taking channel access control; and

the transmitter of the primary explicitly activating one or more secondary flows within the time slot.

4. The method as recited in claim 1, wherein the scheduling by the coordinator of the WPAN comprises assigning by the coordinator of the WPAN the at least one of the one or more transmission flows to a time slot where an un-registered flow is active.

5. The method as recited in claim 1, wherein the interference report includes interference information during periods of time when the one of the one or more devices of the WPAN is active and during periods of time when the one of the one or more devices of the WPAN is inactive.

6. The method as recited in claim 5, where the interference information during the periods of time when the one of the one or more devices of the WPAN is active includes signal to noise ratio information.

7. The method as recited in claim 5, where the interference information during the periods of time when the one of the one or more devices of the WPAN is inactive includes noise strength and power information.

8. The method as recited in claim 1, wherein:

the interference report is received by the coordinator of the WPAN during a pre-scheduled time slot in the super-frame, the pre-scheduled time slot separate from time slots in the super-frame scheduled for transmission flows; and

each receiving device in the WPAN scheduled to receive during the super-frame transmits an interference report during the pre-scheduled time slot.

9. The method as recited in claim 1, wherein the interference report is received on a non-periodic basis;

and

the interference report is triggered by a substantial change in an interference level during a time slot of a super-frame or by signal quality degradation during a time slot of a super-frame.

10. The method as recited in claim 1, wherein the one or more transmission flows are directional communications.

17. The method as recited in claim 1, wherein:

the generating comprises generating by the coordinator of the WPAN the transmission schedule for the subsequent super-frame, wherein at most one transmission flow is scheduled per time slot of the subsequent super-frame.

18. The method as recited in claim 1, wherein the WPAN operates pursuant to the standards of IEEE 802.15.3 for millimeter-wave WPANs.

19. The method as recited in claim 3, wherein:

the primary flow comprises TCP data;

the one or more secondary flows comprise a plurality of TCP ACKs; and

the transmitter of the primary flow explicitly activating the one or more secondary flows within the time slot comprises a transmitter of the TCP data explicitly coordinating the plurality of TCP ACKs.

11. An apparatus of a coordinator of a wireless personal area network (WPAN), the WPAN operating pursuant to standards promulgated by a WPAN standardization body, the apparatus comprising:

an antenna system;

a receiver to receive on the antenna system a bandwidth request for one or more transmission flows from one or more devices of the WPAN, wherein a transmission flow comprises a transfer of data from a transmitting device to a receiving device, and to receive an interference report or interference reports from one or more devices of the WPAN; and

a scheduler to generate a transmission schedule for a super-frame based on the interference report or interference reports from the one or more devices of the WPAN;

wherein the scheduler schedules a plurality of transmission flows to a time slot of the super-frame; and

generates a transmission schedule for a subsequent super-frame based on the interference report from the one or more devices of the WPAN, wherein the same plurality of transmission flows are scheduled in the subsequent super-frame as in the super-frame, and the order of the transmission flows in the subsequent super-frame is changed from the order of the transmission flows in the super-frame, the change in order to reduce interference.

12. The apparatus as recited in claim 11, further comprising the scheduler to assign two or more flows to a same time slot, wherein the two or more flows are a bidirectional flow, comprising a transmission from a first device to a second device and a transmission from the second device to the first device.

13. The apparatus as recited in claim 11, further comprising the scheduler to assign a primary flow to a time slot, wherein a transmitter of the primary flow is to coordinate any secondary flows within the time slot, the coordinating comprising the transmitter of the primary flow to take channel access control and to explicitly activate one or more secondary flows within the time slot.

14. The apparatus as recited in claim 11, the receiver further comprising an out-of-band channel communication interface to receive the interference report.

15. A method for transmissions in a wireless personal area network (WPAN), the WPAN operating pursuant to standards of a WPAN standardization body, the method comprising:

registering by a device of the WPAN with a coordinator of the WPAN one or more transmission flows from the device of the WPAN to one or more other devices of the WPAN, wherein a transmission flow comprises a transfer of data from a transmitting device to a receiving device;

transmitting to the coordinator of the WPAN a bandwidth request for at least one of the one or more transmission flows;

receiving from the coordinator of the WPAN a super-frame, the super-frame scheduling the at least one of the one or more transmission flows, wherein the scheduling comprises assigning a primary flow to a time slot of the super-frame;

transmitting by the device of the WPAN the primary flow;

taking channel access control by the device of the WPAN; and

explicitly activating by the device of the WPAN one or more secondary flows within the time slot of the super-frame.

16. The method as recited in claim 15, wherein the one or more transmission flows are directional communications.

20. The method as recited in claim 15, wherein:

the primary flow comprises TCP data;

the one or more secondary flows comprise a plurality of TCP ACKs; and

the explicitly activating the one or more secondary flows comprises a transmitter of the TCP data explicitly coordinating the plurality of TCP ACKs.