REDIRECTING HANDOVERS IN LTE NETWORKS

• US 20120040662A1
• Filed: 08/12/2010
• Published: 02/16/2012
• Est. Priority Date: 08/12/2010
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Rahman, Moshiur, Opara, Christopher
• Granted Patent: US 8,644,832 B2
• Time in Patent Office: Days
• US Class Current: 455/423
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 36/0016 Hand-off preparation specially adapted for end-to-end data sessions
• CPC Class Codes: H04W 36/0022 for transferring data sessions between adjacent core network technologies
• CPC Class Codes: H04W 36/0079 in case of hand-off failure or rejection
• CPC Class Codes: H04W 40/20 based on geographic position or location
• CPC Class Codes: H04W 40/36 due to handover

Abstract

The disclosed subject matter relates to an architecture that can redirect communications upon detection of a handover failure in a Long Term Evolution (LTE) network. In particular, the architecture can obtain information indicative of a handover failure that is available in a first portion of the LTE network that has no control over the communication path. Furthermore, the architecture can utilize the information to instruct a second portion of the LTE network, one that can control the communication path but conventionally has no access to the information, to reroute the communication path to avoid unresponsive or failing network entities.

Claims

1. A system that redirects communications upon detection of a handover failure in a Long Term Evolution (LTE) network, comprising:

a monitor component operatively coupled to a serving gateway (SGW) of a LTE-access network, wherein the monitor component is configured to identify a failure associated with a LTE handover procedure and to provide a failure notification; and

a routing component operatively coupled to a mobility management entity (MME) of the LTE-access network, wherein the routing component is configured to instruct the MME to select an alternative communication path upon receipt of the failure notification.

2. The system of claim 1, wherein the routing component is further configured to instruct the MME to select an alternate radio access technology (RAT) for the alternative communication path, wherein the alternate RAT differs from a LTE-based evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (eUTRAN).

3. The system of claim 2, wherein the alternate RAT is associated with at least one of a second generation partnership project (2GPP) communication standard, a third generation partnership project (3GPP) communication standard, or a satellite-based communication standard.

4. The system of claim 2, wherein the MME is configured to redirect the communication path by way of the alternate RAT prior to losing a network data connection.

5. The system of claim 1, wherein the monitor component is further configured to identify the failure based upon an unavailability condition associated with a target evolved NodeB (eNB).

6. The system of claim 1, wherein the monitor component is further configured to identify the failure based upon a degraded air interface between user equipment (UE) and a source evolved NodeB (eNB) or between the UE and a target eNB.

7. The system of claim 1, wherein the monitor component is further configured to identify the failure based upon a buffer overflow condition or a packet loss condition associated with at least one of a source evolved NodeB (eNB) or a target eNB.

8. The system of claim 1, wherein the monitor component is further configured to identify the failure based upon a threshold crossing alarm (TCA) count associated with at least one of a source evolved NodeB (eNB) or a target eNB.

9. The system of claim 1, wherein the routing component further instructs the MME to interact with a home subscriber server (HSS) by way of non access stratum (NAS) signaling for determining parameters associated with quality of service (QoS) or service level agreement (SLA).

10. The system of claim 1, wherein the LTE handover procedure is directed to a backward handover initiated by a source evolved NodeB (eNB) or to a forward handover initiated by user equipment (UE).

11. A system that predicts handover difficulties in a Long Term Evolution (LTE) network, comprising:

a monitor component operatively coupled to a serving gateway (SGW) of a LTE-access network, wherein the monitor component is configured to identify a failing evolved NodeB (eNB) that is potentially unable to accept a LTE-based handover;

a tracking component configured to store information associated with the failing eNB; and

a routing component operatively coupled to a mobility management entity (MME) of the LTE-access network, wherein the routing component is configured to instruct the MME to select an alternative communication path upon receipt of a LTE handover request associated with the failing eNB.

12. The system of claim 11, wherein the monitor component is further configured to identify the failing eNB based upon a threshold crossing alarm (TCA) count associated with the failing eNB.

13. The system of claim 11, wherein the monitor component is further configured to identify the failing eNB based upon a degraded air interface between user equipment (UE) and the failing eNB.

14. The system of claim 11, wherein the monitor component is further configured to identify the failing eNB based upon a buffer overflow condition or a packet loss condition associated with the failing eNB.

15. The system of claim 11, wherein the routing component is further configured to instruct the MME to select an alternate radio access technology (RAT) for the alternative communication path, wherein the alternate RAT differs from an LTE-based evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (eUTRAN).

16. The system of claim 15, wherein the alternate RAT is associated with at least one of a second generation partnership project (2GPP) communication standard, a third generation partnership project (3GPP) communication standard, or a satellite-based communication standard.

17. The system of claim 15, wherein the routing component is further configured to instruct the MME to employ the alternate RAT to bypass the failing eNB in connection with the LTE-based handover.

18. A method for rerouting handover transactions in a Long Term Evolution (LTE) network, comprising:

executing, using at least one processor, computer-readable instructions for performing acts, including;

monitoring information received by a serving gateway (SGW) of a LTE-access network;

employing the information for determining a failure associated with a LTE handover procedure;

transmitting a failure notification to a mobility management entity (MME) upon determining the failure; and

instructing the MME to select an alternative communication path upon receipt of the failure notification.

19. The method of claim 18, further comprising at least one of the following:

selecting a disparate radio access technology (RAT) for the alternative communication path;

selecting the disparate RAT based upon non-access stratum (NAS) signaling associated with a home subscriber server (HSS);

selecting at least one second generation partnership project (2GPP) network entity for the alternative communication path;

selecting at least one third generation partnership project (3GPP) network entity for the alternative communication path;

selecting at least one satellite network entity for the alternative communication path;

or

rerouting communication via the alternate communication path prior to dropping a network data connection.

20. The method of claim 18, further comprising at least one of the following:

determining the failure based upon a degraded air interface condition between user equipment (UE) and a source evolved node B (eNB) or between UE and a target eNB;

determining the failure based upon a buffer overflow condition or a packet loss condition associated with at least one of a source eNB or a target eNB;

determining the failure based upon an unavailability condition associated with a target eNB;

determining the failure based upon a threshold crossing alarm (TCA) count associated with at least one of a source eNB or a target eNB;

or

determining the failure in connection with a backward handover initiated by a source eNB or with a forward handover initiated by UE.