Adaptive Methods For Wireless Camera Communication

• US 20160173805A1
• Filed: 07/30/2014
• Published: 06/16/2016
• Est. Priority Date: 07/30/2013
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Chistopher Claus, Robert Bosch GmbH
• Inventors: Claus, Christopher, Schaut, Martin, Sejalon, Fred, Jain, Vivek, Keshavarzian, Abtin, Venkatraman, Lakshmi
• Granted Patent: US 9,894,311 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 3/40 Scaling of whole images or parts thereof, e.g. expanding or contracting
• CPC Class Codes: H04N 17/004 for digital television systems
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/164 Feedback from the receiver or from the transmission channel
• CPC Class Codes: H04N 21/23805 Controlling the feeding rate to the network, e.g. by controlling the video pump
• CPC Class Codes: H04N 21/2402 Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/41422 located in transportation means, e.g. personal vehicle arrangements specially adapted for transportation systems in broadcast systems H04H20/62
• CPC Class Codes: H04N 21/4223 Cameras H04N23/00 takes precedence
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04N 21/440263 by altering the spatial resolution, e.g. for displaying on a connected PDA
• CPC Class Codes: H04N 21/440281 by altering the temporal resolution, e.g. by frame skipping television signal recording using magnetic recording on tape for reproducing at a rate different from the recording rate H04N5/783
• CPC Class Codes: H04N 21/44227 Monitoring of local network, e.g. connection or bandwidth variations; Detecting new devices in the local network configuring of peripheral devices in general G06F9/4411; monitoring connectivity in data switched networks H04L43/0811
• CPC Class Codes: H04N 21/4524 involving the geographical location of the client retrieval from the Internet by querying based on geographical locations G06F16/9537; systems specially adapted for using geographical information in broadcast systems H04H60/70; protocols in which the network application is adapted for the location of the user terminal in communication control or processing H04L67/52; services making use of the location of users or terminals in wireless networks H04W4/02; locating users or terminals in wireless networks H04W64/00
• CPC Class Codes: H04N 21/64723 Monitoring of network processes or resources, e.g. monitoring of network load traffic related reporting in data switching networks H04L43/062
• CPC Class Codes: H04N 23/63 by using electronic viewfinders
• CPC Class Codes: H04N 23/661 Transmitting camera control signals through networks, e.g. control via the Internet
• CPC Class Codes: H04N 23/667 Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
• CPC Class Codes: H04N 5/44 Receiver circuitry for the reception of television signals according to analogue transmission standards H04N5/14 takes precedence
• CPC Class Codes: H04N 7/0127 : by changing the field or frame frequency of the incoming video signal, e.g. frame rate converter
• CPC Class Codes: H04W 28/24 : Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
• CPC Class Codes: H04W 52/04 : TPC
• CPC Class Codes: H04W 52/241 : taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo

Abstract

In a wireless transmission system, a transmitter sends a plurality of data packets to a receiver. The transmitter identifies channel quality indicators corresponding to properties of a communication channel between the transmitter and the receiver. During operation, the transmitter adjusts one or more parameters that affect the Quality of Service (QoS) of data transmission between the transmitter and receiver to enable data transmission at different quality levels over a range of channel quality levels. In one embodiment, the transmitter sends data packets corresponding to video from a camera to the receiver.

Claims

1. A method of operating an in-vehicle video monitoring system comprising:

generating with a camera in a vehicle a first image frame of an environment exterior to the vehicle, the first image frame having a first resolution and first image quality level;

transmitting with a transmitter operatively connected to the camera the first image frame to a receiver through a wireless channel;

generating with the camera in the vehicle a second image frame of the environment exterior to the vehicle, the second image frame having the first resolution and first image quality level, the second image being generated after generation of the first image frame and after the transmitter beings transmitting the first image frame to the receiver;

transmitting with the transmitter operatively connected to the camera the second image frame to the receiver through the wireless channel after the first image frame is transmitted to the receiver;

displaying with a display device in the vehicle the first image frame and the second image frame received by the receiver, the second image frame being displayed after the first image frame;

identifying with a controller operatively connected to the receiver a plurality of channel quality indicators, corresponding to;

an average frame rate corresponding to the received transmissions of the first and second images;

a first ratio corresponding to an average frame transmission time for the first image frame and the second image frame to a constant time interval for frame transmission corresponding to a first selected rate of frame transmission from the transmitter;

a second ratio corresponding to a sum of the average frame transmission time with an average channel access delay for the first image frame and the second image frame to the constant time interval for frame transmission;

generating with the controller a command to reduce at least one of a frame transmission rate, frame resolution, and frame quality level for a subsequent frame from the camera in response to at least one of the plurality of channel quality indicators being beneath a predetermined quality threshold;

transmitting with the receiver the command to the transmitter and the camera; and

transmitting with the transmitter a third image frame from the camera a second selected frame rate that is less than the first selected frame rate in response to the command.

2. The method of claim 1, the transmission of the first image further comprising:

selecting with the transmitter and the receiver a sub-channel in the wireless channel having a minimum level of interference relative to at least one other sub-channel in the wireless channel; and

transmitting with the transmitter the first image to the receiver using the selected sub-channel.

3. The method of claim 1, the transmission of the first image further comprising:

transmitting with the transmitter the first image to the receiver using a plurality of packets, each packet including a portion of data in the first image and a first packet in the plurality of packets is transmitted at a maximum power level for the transmitter;

receiving with the transmitter a message from the receiver indicating a signal to noise ratio (SNR) of the first packet at the receiver; and

transmitting with the transmitter at least one subsequent packet in the plurality of packets a reduced power level from the transmitter in response to the message from the receiver indicating that the SNR of the first packet exceeds a predetermined threshold.

4. The method of claim 1 further comprising:

generating with the camera the third image frame of the environment exterior to the vehicle, the third image frame having at least one of a second image quality level that is less than the first image quality level and a second resolution that is less than the first resolution in response to the command from the controller.

5. The method of claim 1 further comprising:

generating with the controller another command to increase at least one of the frame transmission rate, frame resolution, and frame quality level for another subsequent frame from the camera in response to each of the plurality of channel quality indicators being above the predetermined quality threshold;

transmitting with the receiver the other command to the transmitter and the camera; and

transmitting with the transmitter a fourth image frame from the camera at an increased average frame rate from the average frame rate corresponding to the received transmissions of the first and second images in response to the command.

6. The method of claim 5 further comprising:

generating with the camera the fourth image frame of the environment exterior to the vehicle, the fourth image frame having at least one of a second image quality level that is greater than the first image quality level and a second resolution that is greater than the first resolution in response to the other command from the controller.

7. The method of claim 1 further comprising:

identifying with a global positioning system device in the vehicle a location of the vehicle; and

generating with the controller another command specifying the frame transmission rate, frame resolution, and frame quality level for generation of the first image frame and the second image frame with reference to predetermined frame transmission rate, frame resolution, and frame quality level for generation that are stored in a memory in association with the location of the vehicle identified by the global positioning system;

transmitting with the receiver the other command to the transmitter and the camera;

generating with the camera the first image frame and the second image frame having the frame resolution and the frame quality level specified in the other command; and

transmitting with the transmitter the first image frame and the second image frame at the frame transmission rate specified in the other command.

8. The method of claim 7 further comprising:

identifying with a clock in the vehicle a time of day; and

generating with the controller the other command specifying the frame transmission rate, frame resolution, and frame quality level for generation of the first image frame and the second image frame with reference to predetermined frame transmission rate, frame resolution, and frame quality level for generation that are stored in a memory in association with the location of the vehicle identified by the global positioning system and the time of day identified by the clock.

9. The method of claim 1, further comprising:

identifying with the controller a plurality of frame resolutions for a plurality of image frames received with the receiver prior to receiving the first image frame;

identifying with the controller one resolution in the plurality of frame resolutions that occurs with a greatest frequency; and

scaling with the controller the first image frame from the first resolution to the one resolution for display with the display device at the one resolution in response to the first resolution being different than the one resolution.