Method and apparatus for medium reservation and medium reservation modification in a communication system

• US 8,102,871 B1
• Filed: 06/09/2006
• Issued: 01/24/2012
• Est. Priority Date: 11/10/2005
• Status: Active Grant

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Ozmo, Inc. (Microchip Technology Incorporated)
• Inventors: Vleugels, Katelijn, Thompson, Barry, Bunger, Nils, Minkin, Ilya
• Primary Examiner(s): Ferris, Derrick
• Assistant Examiner(s): Yeung, Mang
• Application Number:
  US11/423,351
• Time in Patent Office: 2,055 Days
• Field of Search: 370/395.4, 370/395.41, 370/236.1, 370/229, 370/237, 370/447, 370/445, 370/461, 370/462, 370/477
• US Class Current: 370/447
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 74/0816 with collision avoidance

Abstract

In a network environment, a wireless medium is reserved for transmissions. Medium reservation modifications can be requested and granted wherein a master device allocates a medium using reservations that are observed by other devices sharing the medium and a slave device complies with reservations by holding data for transmission until its reservation in time arrives by determining a reserved length of an upcoming transmitting opportunity reserved for a slave device, determining a desired length for transmitting data from the slave device over the medium, comparing the reserved length and the desired length to determine if a medium reservation modification is warranted, if the medium reservation modification is warranted, requesting, during the reserved time covered by the medium reservation, the medium reservation modification, and determining whether to grant or deny the medium reservation modification and conveying the determination to the slave device.

Claims

1. A method for requesting and granting of a medium reservation modification wherein a master device allocates a medium using reservations that are observed by other devices sharing the medium and a slave device complies with reservations by holding data for transmission until its reservation in time arrives, the method comprising:

contending, by the master device, for the medium to obtain a reserved service period, wherein contending is performed between a plurality of devices that each have an ability to take over the medium during a contention period, wherein the plurality of devices does not include the slave device;

determining, at the slave device, a reserved length of an upcoming transmitting opportunity reserved for that slave device, wherein the upcoming transmitting opportunity is part of the reserved service period reserved by the master device after contending for the medium and making a medium reservation;

determining, at the slave device, a desired length for transmitting data from the slave device over the medium;

comparing the reserved length and the desired length to determine if a medium reservation modification is warranted;

if the medium reservation modification is warranted, requesting the medium reservation modification during the reserved service period, using the slave device and the medium; and

determining, at the master device, whether to grant or deny the medium reservation modification and conveying the determination to the slave device.

2. The method of claim 1, wherein the medium reservation modification comprises one of a medium reservation extension or a medium reservation contraction.

3. The method of claim 1, wherein the medium reservation for the slave device is an explicit medium reservation and the medium reservation was a reservation made using a duration field of a packet sent by the master device.

4. The method of claim 1, further comprising transmitting data from the slave device during a modified reservation period if the medium reservation modification is granted.

5. The method of claim 1, wherein the slave device requests a longer or shorter medium reservation instead of, or in addition to, a current reservation, wherein the slave device'"'"'s request occurs before the slave device'"'"'s data transfer begins.

6. The method of claim 1, wherein the medium is part of a wireless communication system.

7. The method of claim 1, wherein the medium is part of a wireless communication system according to an 802.11 specification.

8. The method of claim 1, wherein the medium is part of a wireless communication system according to an 802.11 specification, and the master device is an 802.11 station comprising hardware compatible with the 802.11 specification.

9. The method of claim 8, wherein the master device is associated with a wireless local area network and is also associated with a second network containing the master device and the slave device.

10. The method of claim 9, wherein the wireless local area network is an 802.11 compliant network and the second network is a network that uses 802.11 frame formatting and extensions thereof, but is not entirely compliant with the 802.11 specification.

11. The method of claim 1, wherein the medium is part of a wireless communication system according to an overlay protocol that reuses elements of an 802.11x protocol such that an 802.11x-only device that hears an overlay protocol packet will be able to decode the overlay protocol packet enough to determine that the packet is not for the 802.11x-only device so that the 802.11x-only device can appropriately defer.

12. The method of claim 1, wherein the medium is part of a wireless communication system according to a modified 802.11x wireless PAN protocol using modified 802.11x frame formats.

13. The method of claim 1, wherein the medium is part of a wireless communication system according to a modified 802.11x wireless PAN protocol using modified 802.11 frame formats, wherein the slave device is a low-power peripheral and the master device includes hardware and/or firmware and/or software to communicate the low-power peripheral according to the modified 802.11 WPAN protocol, thereby providing a stand-alone WPAN network built on the modified 802.11 WPAN protocol, wherein the low-power peripheral is a peripheral configured to consume less power than if the peripheral were entirely compliant with an 802.11 protocol.

14. The method of claim 13, wherein the master device is a cell phone.

15. The method of claim 14, wherein the cell phone does not include an 802.11 chip.

16. The method of claim 1, wherein requesting the medium reservation modification comprises:

requesting a first medium reservation extension; and

prior to the end of a current service period, requesting a second medium reservation extension, thereby allowing the slave device to request medium extensions multiple times in the same service period.

17. The method of claim 16, further comprising, following the second medium reservation extension request and prior to the end of a current service period, requesting subsequent medium reservation extensions.

18. The method of claim 16, wherein the second medium reservation extension request is for sending additional data that became available at the slave device since the first medium reservation extension.

19. The method of claim 1, wherein the reserved length of an upcoming transmitting opportunity is determined from fields of a poll frame at the start of the transmitting opportunity.

20. A method for requesting and granting of a medium reservation modification wherein a master device allocates a medium using reservations that are observed by other devices sharing the medium and a slave device complies with reservations by holding data for transmission until its reservation in time arrives, the method comprising:

contending, by the master device, for the medium to obtain a reserved service period;

determining, at the slave device, a reserved length of an upcoming transmitting opportunity reserved for that slave device, wherein the upcoming transmitting opportunity is part of the reserved service period reserved by the master device after contending for the medium and making a medium reservation;

determining, at the slave device, a desired length for transmitting data from the slave device over the medium;

comparing the reserved length and the desired length to determine if a medium reservation modification is warranted;

if the medium reservation modification is warranted, requesting the medium reservation modification during the reserved service period, using the slave device and the medium,

wherein requesting the medium reservation modification comprises;

(a) requesting a first medium reservation extension; and

(b) prior to the end of a current service period, requesting a second medium reservation extension, thereby allowing the slave device to request medium extensions multiple times in the same service period; and

determining, at the master device, whether to grant or deny the medium reservation modification and conveying the determination to the slave device,

wherein the second medium reservation extension request is for sending data that exceeds one or more of a maximum packet size, a maximum fragmentation threshold, or a maximum data transfer size.

21. A method for requesting and granting of a medium reservation modification in a communication system that operates according to an 802.11 specification or variation or modification thereof, wherein a master device allocates a medium using reservations that are observed by other devices sharing the medium and a slave device complies with reservations by holding data for transmission until its reservation in time arrives, the method comprising:

contending, by the master device, for the medium to obtain a reserved service period, wherein contending is performed between a plurality of devices that each have an ability to take over the medium during a contention period, wherein the plurality of devices does not include the slave device;

determining, at the slave device, a reserved length of an upcoming transmitting opportunity reserved for that slave device, wherein the upcoming transmitting opportunity is part of the reserved service period reserved by the master device after contending for the medium and making a medium reservation;

determining, at the slave device, a desired length for transmitting data from the slave device over the medium;

comparing the reserved length and the desired length to determine if a medium reservation modification is warranted;

if the medium reservation modification is warranted, requesting the medium reservation modification during the reserved service period, using the slave device and the medium; and

determining, at the master device, whether to grant or deny the medium reservation modification and conveying the determination to the slave device.