System, method, and computer-readable medium for user equipment handoff within an IP-femtocell network

• US 8,532,054 B2
• Filed: 10/15/2008
• Issued: 09/10/2013
• Est. Priority Date: 06/21/2007
• Status: Active Grant

• Current Assignee: Open Invention Network LLC
• Original Assignee: UbeeAirwalk, Inc. (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Osborn, Christopher Martin Edward
• Primary Examiner(s): LY, ANH VU H
• Application Number:
  US12/252,202
• Publication Number:
  US 20090131049A1
• Time in Patent Office: 1,791 Days
• Field of Search: None
• US Class Current: 370/331
• CPC Class Codes: H04L 2101/385 Uniform resource identifier for session initiation protocol [SIP URI]
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1073 Registration or de-registration
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04M 3/42314 in private branch exchanges
• CPC Class Codes: H04M 3/44 Additional connecting arrangements for providing access to frequently-wanted subscribers, e.g. abbreviated dialling at the subscriber's set H04M1/27; automatic redialling H04M3/424
• CPC Class Codes: H04M 7/009 in systems involving PBX or KTS networks
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/00 Hand-off or reselection arrangements
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/0083 Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/0088 Scheduling hand-off measurements
• CPC Class Codes: H04W 36/08 : Reselecting an access point
• CPC Class Codes: H04W 36/30 : by measured or perceived connection quality data
• CPC Class Codes: H04W 4/14 : Short messaging services, e.g. short message services [SMS] or unstructured supplementary service data [USSD]
• CPC Class Codes: H04W 40/02 : Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 40/20 : based on geographic position or location
• CPC Class Codes: H04W 72/20 : Control channels or signalling for resource management
• CPC Class Codes: H04W 72/27 : between access points
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 76/12 : Setup of transport tunnels
• CPC Class Codes: H04W 84/045 : using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: H04W 88/085 : Access point devices with remote components
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

A system, method, and computer readable medium for provisioning communication services by an IP-based femtocell network is provided. Service of a user equipment may be transferred from one femtocell to another femtocell via a femtocell handoff procedure. Femtocell systems of the femtocell network perform link quality measurements and may distribute the link quality measurements to neighbor femtocells. A femtocell system may periodically evaluate the link quality with the user equipment. If an evaluation is made that the user equipment needs to be transferred to another site, the servicing femtocell site may evaluate the most recent link quality measurements received from neighboring femtocell sites and select a femtocell site for handoff. In the event that the femtocell network is deployed in an area serviced by a macrocellular network, handoff routines may provide preference for transferring the user equipment to a target femtocell system rather than a macrocell site.

Claims

1. A method of providing communication services to a user equipment, comprising:

communicatively coupling a plurality of femtocell systems with a packet-switched backhaul, wherein the packet-switched backhaul communicates with a core network via an internet connection and wherein the plurality of femtocell systems are communicatively coupled with one another via the packet-switched backhaul to enable the plurality of femtocell systems to communicate with one another and wherein one or more of the plurality of femtocell systems periodically transmits one or more link quality metrics to one or more others of the plurality of femtocell systems;

registering the user equipment with a first femtocell system of the plurality of femtocell systems;

measuring a first radio interface quality between the user equipment and the first femtocell system;

measuring a second radio interface quality between the user equipment and a second femtocell system of the plurality of femtocell systems;

transmitting an indication of the second radio interface quality from the second femtocell system to the first femtocell system; and

invoking a handoff procedure from the first femtocell system to the second femtocell system.

2. The method of claim 1, further comprising:

determining, by the first femtocell system, that the first radio interface quality is below a predefined quality threshold; and

determining, by the first femtocell system, that the second radio interface quality is sufficient for the handoff.

3. The method of claim 1, further comprising:

transmitting, by the first femtocell system, a request for handoff to the second femtocell system; and

receiving, by the first femtocell system, a response accepting the handoff from the second femtocell system.

4. The method of claim 1, further comprising allocating, by the second femtocell system, a user agent for the user equipment.

5. The method of claim 4, further comprising transmitting, by the second femtocell system, a registration message to a location service on behalf of the user equipment, wherein the registration message includes an Internet Protocol address assigned to the second femtocell system as a contact for the user equipment.

6. The method of claim 5, further comprising:

receiving the registration message by the location service; and

updating, by the location service, a location associated with the user equipment that specifies an Internet Protocol address assigned to the first femtocell system to the Internet Protocol address assigned to the second femtocell system.

7. The method of claim 1, further comprising maintaining, by the first femtocell system, radio interface quality measurements respectively obtained by at least a subset of the plurality of femtocell systems for evaluation of a candidate femtocell system for handoff when the first radio interface quality is determined to be less than a quality threshold.

8. The method of claim 1, wherein measuring the first radio interface quality is performed by the user equipment, the method further comprising transmitting, by the user equipment, a request for handoff to the first femtocell system.

9. A non-transitory computer-readable medium having computer-executable instructions for execution by a processing system, the computer-executable instructions for providing communication services to a user equipment, the computer-readable medium comprising instructions for:

communicatively coupling a plurality of femtocell systems with a packet-switched backhaul, wherein the packet-switched backhaul communicates with a core network via an internet connection and wherein the plurality of femtocell systems are communicatively coupled with one another via the packet-switched backhaul to enable the plurality of femtocell systems to communicate with one another and wherein one or more of the plurality of femtocell systems periodically transmits one or more link quality metrics to one or more others of the plurality of femtocell systems;

registering the user equipment with a first femtocell system of the plurality of femtocell systems;

measuring a first radio interface quality between the user equipment and the first femtocell system;

measuring a second radio interface quality between the user equipment and a second femtocell system;

transmitting an indication of the second radio interface quality from the second femtocell system to the first femtocell system;

invoking a handoff procedure from the first femtocell system to the second femtocell system; and

allocating, by the second femtocell system, a session initiation protocol user agent for the user equipment.

10. The non-transitory computer-readable medium of claim 9, further comprising instructions for:

determining, by the first femtocell system, that the first radio interface quality is below a predefined quality threshold; and

determining, by the first femtocell system, that the second radio interface quality is sufficient for the handoff.

11. The non-transitory computer-readable medium of claim 9, further comprising instructions for:

transmitting, by the first femtocell system, a request for handoff to the second femtocell system; and

receiving, by the first femtocell system, a response accepting the handoff from the second femtocell system.

12. The non-transitory computer-readable medium of claim 11, further comprising instructions for transmitting, by the second femtocell system, a registration message to a location service on behalf of the user equipment, wherein the registration message includes an Internet Protocol address assigned to the second femtocell system as a contact for the user equipment.

13. The non-transitory computer-readable medium of claim 12, further comprising instructions for:

receiving the registration message by the location service; and

updating, by the location service, a location associated with the user equipment that specifies an Internet Protocol address assigned to the first femtocell system to the Internet Protocol address assigned to the second femtocell system.

14. The non-transitory computer-readable medium of claim 9, further comparing instructions for maintaining, by the first femtocell system, radio interface quality measurements respectively obtained by at least a subset of the plurality of femtocell systems for evaluation of a candidate femtocell system for handoff when the first radio interface quality is determined to be less than a quality threshold.

15. The non-transitory computer-readable medium of claim 9, wherein measuring the first radio interface quality is performed by the user equipment, the method further comprising transmitting, by the user equipment, a request for handoff to the first femtocell system.

16. A system for providing communication services to a user equipment, the system comprising:

a packet-switched network having a domain with which the user equipment has a session initiation protocol service subscription;

an Internet Protocol multimedia subsystem communicatively interfaced with the packet-switched network, the Internet Protocol multimedia subsystem providing a connection between the packet-switched network and a mobile operator Core Network; and

a femtocell network including a plurality of femtocell systems communicatively coupled with one another via an access device that provides access for the plurality of femtocell systems with the packet-switched network to enable the plurality of femtocell systems to communicate with one another and wherein one or more of the plurality of femtocell systems periodically transmits one or more link quality metrics to one or more others of the plurality of femtocell systems, wherein each of the femtocell systems is adapted to provide a radio interface with the user equipment, wherein the femtocell network includes a first femtocell system with which the user equipment is registered and that measures a first radio interface quality between the user equipment and the first femtocell system, wherein a second femtocell system of the femtocell network measures a second radio interface quality between the user equipment and the second femtocell system, and transmits an indication of the second radio interface quality to the first femtocell system, wherein a handoff procedure is invoked to transfer service from the first femtocell system to the second femtocell system, wherein the second femtocell system allocates a session initiation protocol user agent for the user equipment and submits a registration message to a location service on behalf of the user equipment.

17. The system of claim 16, wherein the first femtocell system determines that the first radio interface quality is below a predefined quality threshold and determines that the second radio interface quality is sufficient for the handoff.

18. The system of claim 16, wherein the first femtocell system transmits a request for handoff to the second femtocell system and receives a response accepting the handoff from the second femtocell system.

19. The system of claim 16, wherein the registration message includes an Internet Protocol address assigned to the second femtocell system as a contact for the user equipment.

20. The system of claim 16, wherein the location service receives the registration message and updates a location associated with the user equipment that specifies an Internet Protocol address assigned with the first femtocell system to the Internet Protocol address assigned to the second femtocell system.