Comparative-throughput triggered handoff

• US 8,798,005 B1
• Filed: 12/21/2009
• Issued: 08/05/2014
• Est. Priority Date: 12/21/2009
• Status: Active Grant

• Current Assignee: Sprint Spectrum LLC (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Vargantwar, Sachin R., Shetty, Manoj
• Primary Examiner(s): TRAN, PHUC H
• Application Number:
  US12/643,023
• Time in Patent Office: 1,688 Days
• Field of Search: 370331-332
• US Class Current: 370/332
• CPC Class Codes: H04W 36/0044 of quality context information
• CPC Class Codes: H04W 36/0094 Definition of hand-off measurement parameters
• CPC Class Codes: H04W 36/26 by agreed or negotiated communication parameters
• CPC Class Codes: H04W 8/087 for preserving data network PoA address despite hand-offs

Abstract

Disclosed herein are methods for comparative-throughput triggered handoff. According to one embodiment of the method, the RAN may determine that a higher priority AT is receiving a lower level of throughput than a lower priority AT in the same sector, and as a response, the RAN will cause the higher priority AT to hand off from the current serving sector. According to another embodiment of the method, the RAN may identify which of the ATs being served in a particular sector are receiving lower than a threshold level of throughput, and subsequently determine the highest service priority level of these identified ATs. The RAN will then cause one or more of the identified ATs that have the highest service priority level to hand off from the current serving sector.

Claims

1. A method of managing radio resources in a wireless communication system, the method comprising:

a radio access network (RAN) detecting that a first access terminal served by the RAN in a given coverage area has been receiving a lower throughput level than a second access terminal served by the RAN in the given coverage area, even though the first access terminal has a higher service priority level than the second access terminal,

wherein the RAN detecting that the first access terminal served by the RAN in a given coverage area has been receiving a lower throughput level than the second access terminal served by the RAN in the given coverage area comprises the RAN detecting that the first access terminal has been served less often than the second access terminal, wherein detecting that the first access terminal has been served less often than the second access terminal comprises detecting that fewer data packets per unit time have been transmitted to the first access terminal than have been transmitted to the second access terminal,

wherein throughput comprises a measure of an amount of data communicated between an access terminal and the RAN per a unit of time; and

responsive to the detecting, the RAN causing the first access terminal to hand off from the given coverage area to another coverage area.

2. The method of claim 1, wherein the RAN detecting that the first access terminal served by the RAN in a given coverage area has been receiving a lower throughput level than the second access terminal served by the RAN in the given coverage area comprises:

the RAN detecting that the second access terminal served by the RAN in the given coverage area has been receiving a higher throughput level that the first access terminal served by the RAN in the given coverage area.

3. The method of claim 1, wherein detecting that the first access terminal has been served less often than the second access terminal comprises detecting that there is more time between successive transmissions to the first access terminal compared with time between successive transmissions to the second access terminal.

4. The method of claim 1, wherein throughput comprises a data rate.

5. The method of claim 1, wherein the RAN causing the first access terminal to hand off from the given coverage area to another coverage area comprises:

the RAN transmitting to the first access terminal an instruction to hand off to another coverage area.

6. The method of claim 5, wherein the RAN transmitting to the first access terminal an instruction to hand off to another coverage area comprises:

the RAN transmitting to the first access terminal over a control channel a DRCLock command.

7. A method of managing radio resources in a wireless communication system in which a plurality of access terminals are served by a radio access network (RAN) and are operating in a given coverage area defined by the RAN, the method comprising:

the RAN evaluating throughput of each access terminal of the plurality and thereby identifying, as a subset of the plurality, a group of access terminals that are each receiving lower than a threshold level of throughput in the given coverage area, wherein throughput comprises a measure of an amount of data communicated between an access terminal and the RAN per a unit of time;

of the identified subset of access terminals, the RAN identifying an access terminal having a highest service priority level among service priority levels of the access terminals of the identified subset;

of the identified subset of access terminals, the RAN identifying a second access terminal having the highest service priority level among service priority levels of the access terminals of the identified subset;

the RAN causing the identified access terminal to hand off from the given coverage area to another coverage area; and

the RAN causing the second access terminal to hand off from the given coverage area to another coverage area.

8. The method of claim 7, wherein the RAN evaluating throughput of each access terminal of the plurality and thereby identifying, as a subset of the plurality, a group of access terminals that are each receiving lower than a threshold level of throughput in the given coverage area comprises:

the RAN determining how often each access terminal of the plurality is being served and thereby identifying, as a subset of the plurality, a group of access terminals that are each being served less often than a threshold level in the given coverage area.

9. The method of claim 8, wherein determining how often each access terminal of the plurality is being served comprises determining the amount of time between successive transmissions from the RAN to each access terminal of the plurality, and

wherein identifying, as a subset of the plurality, a group of access terminals that are each being served less often than a threshold level comprises identifying, as a subset of the plurality, a group of access terminals that each have greater than a threshold level of time between successive transmissions from the RAN.

10. The method of claim 8, wherein determining how often each access terminal of the plurality is being served comprises determining how many data packets are being transmitted to each access terminal per unit time.

11. The method of claim 7, wherein throughput comprises a data rate.

12. The method of claim 7, wherein the RAN causing the identified access terminal to hand off from the given coverage area to another coverage area comprises:

the RAN transmitting to the identified access terminal an instruction to hand off to another coverage area.

13. The method of claim 12, wherein the RAN transmitting to the identified access terminal an instruction to hand off to another coverage area comprises:

the RAN transmitting to the identified access terminal over a control channel a DRCLock command.

14. A radio access network (RAN) for serving a plurality of wireless communication devices, the RAN comprising:

one or more antennas for radiating to define two or more coverage areas in which to serve the plurality of wireless communication devices; and

a control node,

wherein the control node detects that a first access terminal served by the RAN in a given coverage area has been receiving a lower throughput level than a second access terminal served by the RAN in the given coverage area and that the first access terminal has a higher service priority level than the second access terminal,

wherein the control node detecting that the first access terminal served by the RAN in a given coverage area has been receiving a lower throughput level than the second access terminal served by the RAN in the given coverage area comprises the RAN detecting that the first access terminal has been served less often than the second access terminal, wherein detecting that the first access terminal has been served less often than the second access terminal comprises detecting that fewer data packets per unit time have been transmitted to the first access terminal than have been transmitted to the second access terminal,

wherein throughput comprises a measure of an amount of data communicated between an access terminal and the RAN per a unit of time, and

wherein, responsive to the detecting, the control node causes the first access terminal to hand off from the given coverage area to another coverage area.

15. The RAN of claim 14, wherein the control node detects that a first access terminal served by the RAN in a given coverage area has been receiving a lower throughput level than a second access terminal served by the RAN in the given coverage area by detecting that the first access terminal is being served less often than the second access terminal.