Cell selection for airborne mobile cellular communications equipment

• US 10,111,152 B2
• Filed: 12/09/2015
• Issued: 10/23/2018
• Est. Priority Date: 12/09/2015
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Axmon, Joakim, Alriksson, Peter, Lindoff, Bengt, Ekelund, Bjorn
• Primary Examiner(s): Eng, George
• Assistant Examiner(s): Ahsan, Umair
• Application Number:
  US14/963,398
• Publication Number:
  US 20170171792A1
• Time in Patent Office: 1,049 Days
• CPC Class Codes: H04B 7/18506 Communications with or from aircraft, i.e. aeronautical mobile service
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 36/083 wherein at least one of the access points is a moving node
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/324 by mobility data, e.g. speed data
• CPC Class Codes: H04W 36/328 by altitude
• CPC Class Codes: H04W 56/0035 detecting errors in frequency or phase
• CPC Class Codes: H04W 84/005 Moving wireless networks
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185

Abstract

A network node in a cellular telecommunications system hands over responsibility for serving a wireless communication equipment from a serving cell to a target cell, wherein the wireless communication equipment is situated in a first aircraft that is in-flight. An aircraft position, an aircraft velocity, and an aircraft direction are determined. For each candidate cell of a number of candidate cells, a level of beam distortion that would result from a beam directed from the candidate cell to the first aircraft is predicted. The target cell is selected from the candidate cells by identifying which of the candidate cells has a least amount of predicted beam distortion. The target cell is then signaled to prepare for a handover of responsibility for serving the wireless communication equipment.

Claims

1. A method of handing over responsibility for serving a wireless communication equipment from a serving cell to a target cell in a cellular telecommunications system, wherein the wireless communication equipment is situated in a first aircraft that is in-flight, wherein the method is performed by a network node of the cellular telecommunications system, the method comprising:

determining an aircraft position, an aircraft velocity, and an aircraft direction for the first aircraft;

for each candidate cell of a plurality of candidate cells, using at least one of the aircraft position, the aircraft velocity, and the aircraft direction to predict a level of Doppler shift that would result from a beam directed from the candidate cell to the first aircraft;

selecting the target cell from the plurality of candidate cells by identifying which of the plurality of candidate cells minimizes an amount of change between the predicted Doppler shift and a present Doppler shift through a candidate handover from the serving cell to the candidate cell, and selecting the identified candidate cell as the target cell, wherein the present Doppler shift results from a beam directed from the serving cell to the first aircraft; and

signaling the target cell to prepare for a handover of responsibility for serving the wireless communication equipment.

2. The method of claim 1, wherein determining the aircraft position, the aircraft velocity, and the aircraft direction comprises:

periodically acquiring, via an aircraft navigation broadcast receiver, acquired navigation information transmitted from the first aircraft, wherein the acquired navigation information comprises;

the position of the first aircraft;

an altitude of the first aircraft; and

a time value indicating when the position of the first aircraft was determined; and

determining the velocity and the direction from the periodically acquired navigation information.

3. A method of handing over responsibility for serving a wireless communication equipment from a serving cell to a target cell in a cellular telecommunications system, wherein the wireless communication equipment is situated in a first aircraft that is in-flight, wherein the method is performed by a network node of the cellular telecommunications system, the method comprising:

determining an aircraft position, an aircraft velocity, and an aircraft direction for the first aircraft;

for each candidate cell of a plurality of candidate cells, predicting a level of beam distortion through a handover that would result from a beam directed from the candidate cell to the first aircraft;

selecting the target cell from the plurality of candidate cells by identifying which of the plurality of candidate cells has a least amount of predicted beam distortion through the handover; and

signaling the target cell to prepare for a handover of responsibility for serving the wireless communication equipment,

wherein predicting the level of beam distortion through the handover that would result from the beam directed from the candidate cell to the first aircraft comprises;

predicting for a given future moment in time, an azimuth and direction of a beam from the candidate cell to the first aircraft;

predicting for the given future moment in time, an azimuth and direction of a beam from the candidate cell to a second aircraft having onboard wireless communication equipment in need of cellular communication system service;

determining a degree of similarity between the predicted azimuth and direction of the beam from the candidate cell to the first aircraft and the predicted azimuth and direction of the beam from the candidate cell to the second aircraft; and

using the degree of similarity as an indicator of the level of beam distortion.

4. An apparatus for handing over responsibility for serving a wireless communication equipment from a serving cell to a target cell in a cellular telecommunications system, wherein the wireless communication equipment is situated in a first aircraft that is in-flight, wherein the apparatus is associated with a network node of the cellular telecommunications system, the apparatus comprising:

circuitry configured to determine an aircraft position, an aircraft velocity, and an aircraft direction for the first aircraft;

circuitry configured to use at least one of the aircraft position, the aircraft velocity, and the aircraft direction to predict, for each candidate cell of a plurality of candidate cells, a level of Doppler shift that would result from a beam directed from the candidate cell to the first aircraft;

circuitry configured to select the target cell from the plurality of candidate cells by identifying which of the plurality of candidate cells minimizes an amount of change between the predicted Doppler shift and a present Doppler shift through a candidate handover from the serving cell to the candidate cell, and selecting the identified candidate cell as the target cell, wherein the present Doppler shift results from a beam directed from the serving cell to the first aircraft; and

circuitry configured to signal the target cell to prepare for a handover of responsibility for serving the wireless communication equipment.

5. The apparatus of claim 4, wherein the circuitry configured to determine the aircraft position, the aircraft velocity, and the aircraft direction comprises:

circuitry configured to periodically acquire, via an aircraft navigation broadcast receiver, acquired navigation information transmitted from the first aircraft, wherein the acquired navigation information comprises;

the position of the first aircraft;

an altitude of the first aircraft; and

a time value indicating when the position of the first aircraft was determined; and

circuitry configured to determine the velocity and the direction from the periodically acquired navigation information.

6. An apparatus for handing over responsibility for serving a wireless communication equipment from a serving cell to a target cell in a cellular telecommunications system, wherein the wireless communication equipment is situated in a first aircraft that is in-flight, wherein the apparatus is associated with a network node of the cellular telecommunications system, the apparatus comprising:

circuitry configured to determine an aircraft position, an aircraft velocity, and an aircraft direction for the first aircraft;

circuitry configured to predict, for each candidate cell of a plurality of candidate cells, a level of beam distortion through a handover that would result from a beam directed from the candidate cell to the first aircraft;

circuitry configured to select the target cell from the plurality of candidate cells by identifying which of the plurality of candidate cells has a least amount of predicted beam distortion through the handover; and

circuitry configured to signal the target cell to prepare for a handover of responsibility for serving the wireless communication equipment,

wherein the circuitry configured to predict the level of beam distortion through the handover that would result from the beam directed from the candidate cell to the first aircraft comprises;

circuitry configured to predict for a given future moment in time, an azimuth and direction of a beam from the candidate cell to the first aircraft;

circuitry configured to predict for the given future moment in time, an azimuth and direction of a beam from the candidate cell to a second aircraft having onboard wireless communication equipment in need of cellular communication system service;

circuitry configured to determine a degree of similarity between the predicted azimuth and direction of the beam from the candidate cell to the first aircraft and the predicted azimuth and direction of the beam from the candidate cell to the second aircraft; and

circuitry configured to use the degree of similarity as an indicator of the level of beam distortion.

7. A nontransitory computer readable storage medium comprising program instructions that, when performed by one or more processors of a network node of a cellular telecommunications system, cause the network node to perform a method of handing over responsibility for serving a wireless communication equipment from a serving cell to a target cell in the cellular telecommunications system, wherein the wireless communication equipment is situated in a first aircraft that is in-flight, and wherein the method comprises:

determining an aircraft position, an aircraft velocity, and an aircraft direction for the first aircraft;

for each candidate cell of a plurality of candidate cells, using at least one of the aircraft position, the aircraft velocity, and the aircraft direction to predict a level of Doppler shift that would result from a beam directed from the candidate cell to the first aircraft;

selecting the target cell from the plurality of candidate cells by identifying which of the plurality of candidate cells minimizes an amount of change between the predicted Doppler shift and a present Doppler shift through a candidate handover from the serving cell to the candidate cell, wherein the present Doppler shift results from a beam directed from the serving cell to the first aircraft; and

signaling the target cell to prepare for a handover of responsibility for serving the wireless communication equipment.

8. A method of handing over responsibility for serving a wireless communication equipment from a serving cell to a target cell in a cellular telecommunications system, wherein the wireless communication equipment is situated in a first aircraft that is in-flight, wherein the method is performed by a network node of the cellular telecommunications system, the method comprising:

determining an aircraft position, an aircraft velocity, and an aircraft direction for the first aircraft;

for each candidate cell of a plurality of candidate cells, using at least one of the aircraft position, the aircraft velocity, and the aircraft direction to predict for a given future moment in time, a beam angle between a first vector representing the trajectory of the first aircraft and a second vector between the first aircraft and a candidate cell antenna, wherein the first and second vectors are vectors in a Euclidean three-dimensional space; and

selecting the target cell from the plurality of candidate cells by identifying which of the plurality of candidate cells minimizes an amount of change between the predicted beam angle and a present beam angle, and selecting the identified candidate cell as the target cell, wherein the present beam angle is between the first vector and a third vector between the first aircraft and a serving cell antenna; and

signaling the target cell to prepare for a handover of responsibility for serving the wireless communication equipment.

9. The method of claim 8, wherein:

selecting the target cell from the plurality of candidate cells comprises;

identifying which of the candidate cells has the beam angle that is closest to being normal to the first aircraft direction.

10. The method of claim 8, wherein:

selecting the target cell from the plurality of candidate cells comprises;

identifying which of the candidate cells has the beam angle that is closest to being tangential to the first aircraft direction.

11. The method of claim 8, comprising:

predicting for the given future moment in time, a first angle between the first vector representing the trajectory of the first aircraft and the third vector between the first aircraft and the serving cell antenna, wherein the third vector is a vector in the Euclidean three-dimensional space; and

wherein;

selecting the target cell from the plurality of candidate cells comprises;

identifying which of the candidate cells has the beam angle that is most like the first angle.

12. An apparatus for handing over responsibility for serving a wireless communication equipment from a serving cell to a target cell in a cellular telecommunications system, wherein the wireless communication equipment is situated in a first aircraft that is in-flight, wherein the apparatus is associated with a network node of the cellular telecommunications system, the apparatus comprising:

circuitry configured to determine an aircraft position, an aircraft velocity, and an aircraft direction for the first aircraft;

circuitry configured to use at least one of the aircraft position, the aircraft velocity, and the aircraft direction, to predict for each candidate cell of a plurality of candidate cells, for a given future moment in time, a beam angle between a first vector representing the trajectory of the first aircraft and a second vector between the first aircraft and a candidate cell antenna, wherein the first and second vectors are vectors in a Euclidean three-dimensional space; and

circuitry configured to select the target cell from the plurality of candidate cells by identifying which of the plurality of candidate cells minimizes an amount of change between the predicted beam angle and a present beam angle, and select the identified candidate cell as the target cell, wherein the present beam angle is between the first vector and a third vector between the first aircraft and a serving cell antenna; and

circuitry configured to signal the target cell to prepare for a handover of responsibility for serving the wireless communication equipment.

13. The apparatus of claim 12, wherein:

the circuitry configured to select the target cell from the plurality of candidate cells comprises;

circuitry configured to identify which of the candidate cells has the beam angle that is closest to being normal to the first aircraft direction.

14. The apparatus of claim 12, wherein:

the circuitry configured to select the target cell from the plurality of candidate cells comprises;

circuitry configured to identify which of the candidate cells has the beam angle that is closest to being tangential to the first aircraft direction.

15. The apparatus of claim 12, comprising:

circuitry configured to predict for the given future moment in time, a first angle between the first vector representing the trajectory of the first aircraft and the third vector between the first aircraft and the serving cell antenna, wherein the third vector is a vector in the Euclidean three-dimensional space; and

wherein;

the circuitry configured to select the target cell from the plurality of candidate cells comprises;

circuitry configured to identify which of the plurality of candidate cells has the beam angle that is most like the first angle.