Protocol for improved utilization of a wireless network using interference estimation

Abstract

Disclosed is a protocol used by wireless stations sharing a single wireless channel. When a local station senses a communication between remote stations using the channel, the local station estimates whether its local transmissions would disrupt this on-going remote communication. To estimate, the local station forms capture models of the remote stations. From the capture models, the local station determines if its local transmission would prevent each remote station from capturing the signal from the other remote station. If the local transmission would not disrupt the remote communications, the local station transmits its message over the channel at the same time the remote stations use the channel. The local station performs the estimation using parameters of the remote stations. The stations could share their parameters by including them in headers of frames. The protocol can be implemented as an enhancement to the IEEE 802.11 standard.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a illustrates a wired computer network.

FIG. 1 b illustrates two devices in a network exchanging frames.

FIG. 1 c illustrates a device in a wired network transmitting a frame over a channel.

FIG. 1 d illustrates a frame format.

FIG. 2 a illustrates a wireless network

FIG. 2 b illustrates a station in a wireless network transmitting a frame.

FIG. 3 a illustrates a wireless station receiving two signals concurrently.

FIG. 3 b illustrates a timeline of frames transmitted over a wireless network.

FIG. 4 a illustrates a physical carrier sensing method.

FIGS. 4 b and 4c illustrate a virtual carrier sensing method.

FIG. 5 a illustrates a local wireless station receiving a signal from a remote wireless station.

FIG. 5 b illustrates a local wireless station receiving signals from two remote wireless stations.

FIGS. 6 a and 6b illustrate wireless stations communicating over a wireless network.

FIG. 7 illustrates a channel access method using interference estimation.

FIGS. 8 and 9 illustrate an interference estimation method in greater detail.

FIG. 10 illustrates an enhanced frame format.

Claims

1. A method of operating a local wireless station comprising: detecting a remote communication between a transmitting station and a receiving station over a wireless channel;determining whether a local transmission using the wireless channel would interfere with the remote communication using a model of the capture effects at the receiving station; andin response to the determination, broadcasting a local transmission over the wireless channel concurrently with a transmission from the transmitting station.

2. The method of claim 1, wherein the model of the capture effects at the receiving station is based on: a power of a transmission from the transmitting station at the location of the receiving station; anda power of a transmission from the local station at the location of the receiving station.

3. The method of claim 2, wherein at least one of the powers is calculated using a signal propagation model.

4. The method of claim 3, wherein the signal propagation model is based on information describing the physical location of the receiving station relative to a reference.

5. The method of claim 4, wherein the information is acquired using a radio frequency based localization method.

6. The method of claim 1, wherein the transmitting station transmits a frame that includes a parameter used in the model of the capture effects.

7. The method of claim 6, wherein all frames transmitted by the transmitting station include a field for storing a parameter used in the model of the capture effects.

8. The method of claim 6, wherein the local station stores the parameter in a memory and updates the stored parameter in response to receiving an updated value from the transmitting station.

9. The method of claim 8, wherein the local station performs the determining every time it updates the stored parameter.

10. The method of claim 6, wherein the parameter describes the location of one of the transmitting or receiving stations relative to a reference.

11. An apparatus that performs any one of the methods according to claims 1-10.

12. A computer readable medium storing a program that causes a computer to perform any one of the methods according to claims 1-10.

13. A method of operating a local wireless station, comprising: detecting a frame transmitted wirelessly from a first wireless station to a second wireless station over a wireless communication channel;extracting from a header in the frame characteristics of the first and second stations;based on the extracted characteristics and a signal propagation model, calculating the powers of: a signal transmitted from the local station at the locations of the first and second stations,a signal transmitted from the first station at the location of the second station, anda signal transmitted from the second station at the location of the first station;estimating whether the signal transmitted from the local station would prevent the first station from capturing a signal transmitted from the second station and would prevent the second station from capturing a signal transmitted from the first station using a capture effect model; andin response to the estimating, transmitting a frame addressed to a third wireless station over the wireless communication channel concurrently with a transmission from either the first or second stations.