Method of handover in a cellular radio network

• US 9,161,283 B2
• Filed: 12/07/2010
• Issued: 10/13/2015
• Est. Priority Date: 12/07/2010
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Kallin, Harald, Olin, Birgitta
• Primary Examiner(s): Magloire, Vladimir
• Assistant Examiner(s): Zewari, Sayed T
• Application Number:
  US13/990,734
• Publication Number:
  US 20130344871A1
• Time in Patent Office: 1,771 Days
• Field of Search: 455/436, 455/437, 455/438, 455/439, 455/440, 455/441, 455/442, 455/443, 455/444, 455/445, 455/446
• US Class Current: 1/1
• CPC Class Codes: H04W 36/302 due to low signal strength
• CPC Class Codes: H04W 36/38 by fixed network equipment

Abstract

A method in a radio network node (105) for handling handover of a user equipment (110) from a first cell (115) to a second cell (120) is provided. A first scenario (410, 510), associated with a radio quality of the first cell (115) and a radio quality of the second cell (120), and a second scenario (420, 520), associated with a radio quality of the first cell (115) and a radio quality of the second cell (120), are defined. Also defined is at least one individual handover parameter (210, 220) for each one of the scenarios. Measured radio qualities of the first and second cells, associated with the user equipment (110) are obtained. The user equipment (110) is then classified into one of the scenarios based on the measured radio qualities, and a handover decision is established based on the individual handover parameter (210, 220) for the chosen scenario.

Claims

1. A method in a radio network node for handling handover of a first user equipment from a first cell to a second cell, which first cell, second cell and which radio network node are comprised in a wireless communication system, the method comprising:

defining a first scenario associated with a first radio quality of the first cell, a second radio quality of the second cell, and a first border crossing between the first and second cells,

defining a second scenario associated with a third radio quality of the first cell, a fourth radio quality of the second cell, and a second border crossing between the first and second cells,

defining at least one individual handover parameter for each one of the respective first scenario and second scenario,

obtaining a measurement report comprising a first measured radio quality of the first cell and a second measured radio quality of the second cell, which first measured radio quality and second measured radio quality are associated with the first user equipment,

classifying the first user equipment into one of the first scenario or the second scenario based on the first measured radio quality and the second measured radio quality,

establishing a handover decision based on the at least one individual handover parameter defined for the scenario into which the first user equipment is classified,

wherein the radio network node has obtained a third measured radio quality associated with a second user equipment within the wireless communication system and/or the radio network node has obtained a first handover result associated with the first user equipment and a second handover result associated with a third user equipment within the wireless communication system,

the method further comprises;

performing a first analysis of said first measured radio quality, said second measured radio quality and/or said third measured radio quality, and/or performing a second analysis of said first handover result and/or said second handover result,

and

tuning one or more of the at least one individual handover parameter based on the first analysis of said first measured radio quality, said second measured radio quality and/or said third measured radio quality and/or based on the second analysis of said first handover result and/or said second handover result.

2. The method according to claim 1, wherein said tuning is performed adaptively.

3. The method according to claim 1, further comprising:

redefining the first scenario and/or the second scenario based on the first analysis and/or the second analysis.

4. The method according to claim 3, wherein said redefining is performed adaptively.

5. The method according to claim 1, further comprising:

obtaining a position measurement associated with the first user equipment and wherein said classifying further is based on the obtained position measurement.

11. The method of claim 1,

wherein the first and second scenarios correspond to different respective first and second travel routes for user equipment between the first and second cells, and

wherein defining at least one individual handover parameter for each one of the respective first scenario and second scenario comprises defining different respective handover parameters for the first and second scenarios.

13. The method of claim 1,

wherein the first scenario corresponds to a first combination of the first radio quality of the first cell and the second radio quality of the second cell, and

wherein the second scenario corresponds to a second combination of the third radio quality of the first cell and the fourth radio quality of the second cell.

6. A radio network node for handling handover of a first user equipment from a first cell to a second cell, which first cell, second cell and which radio network node are comprised in a wireless communication system, said radio network node comprising a processor, which processor comprises:

a defining unit configured to define a first scenario associated with a first radio quality of the first cell, a second radio quality of the second cell, and a first border crossing between the first and second cells,

which defining unit further is configured to define a second scenario associated with a third radio quality of the first cell, a fourth radio quality of the second cell, and a second border crossing between the first and second cells,

and which defining unit further is configured to define at least one individual handover parameter for each one of the respective first scenario and second scenario,

the radio network node further comprising

a receiver configured to obtain a measurement report comprising a first measured radio quality of the first cell and a second measured radio quality of the second cell, which first measured radio quality and second measured radio quality are associated with the first user equipment,

the processor further comprising

a classification unit configured to classify the first user equipment into one of the first scenario or the second scenario based on the first measured radio quality and the second measured radio quality,

the processor further comprising

a decision unit configured to establish a handover decision based on the at least one individual handover parameter defined for the scenario into which the first user equipment is classified, wherein the receiver is configured to obtain a third measured radio quality associated with a second user equipment and/or configured to obtain a first handover result associated with the first user equipment and a second handover result associated with a third user equipment within the wireless communication system,

said radio network node further comprising;

an analysing unit configured to perform a first analysis of said first measured radio quality, said second measured radio quality and/or said third measured radio quality and/or perform a second analysis of said first handover result and/or said second handover result,

and the processor further comprises;

a tuning unit configured to tune one or more of the at least one individual handover parameter based on the first analysis of said first measured radio quality, said second measured radio quality and/or said third measured radio quality and/or based on the second analysis of said first handover result and/or said second handover result.

7. The radio network node according to claim 6, wherein said tuning unit is configured to tune said one or more of the at least one individual handover parameter adaptively.

8. The radio network node according to claim 6, wherein the processor further comprises:

a redefining unit configured to redefine the first scenario and/or the second scenario based on the first analysis and/or second analysis.

9. The radio network node according to claim 8, wherein said redefining unit is configured to redefine said first scenario and/or second scenario adaptively.

10. The radio network node according to claim 6, wherein the receiver further is configured to:

obtain a position measurement associated the first user equipment and wherein said classification unit further is configured to classify said first user equipment into one of the first scenario or the second scenario based on the first measured radio quality, the second measured radio quality and on the obtained position measurement.

12. The radio network node of claim 6,

wherein the first and second scenarios correspond to different respective first and second travel routes for user equipment between the first and second cells, and

wherein the defining unit is configured to define different respective handover parameters for the first and second scenarios.

14. The radio network node of claim 6,

wherein the first scenario corresponds to a first combination of the first radio quality of the first cell and the second radio quality of the second cell, and

wherein the second scenario corresponds to a second combination of the third radio quality of the first cell and the fourth radio quality of the second cell.