Self-Backhauling in LTE

• US 20110044279A1
• Filed: 09/09/2008
• Published: 02/24/2011
• Est. Priority Date: 04/30/2008
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Hoymann, Christian, Lundsjö, Johan, Johansson, Niklas, Mildh, Gunnar, Ràcz, András
• Granted Patent: US 8,797,952 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 47/825 Involving tunnels, e.g. MPLS
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 92/20 between access points

Abstract

A method implemented in an anchor base station configured performing a proxy operation at an anchor base station in which the anchor base station acts as a proxy between a second S-GW or an MME node and a self-backhauled base station. The method includes receiving a data packet destined for the user equipment and mapping the received data packet from an incoming General Packet Radio Service (GPRS) Tunneling Protocol (GTP) tunnel to an outgoing GTP tunnel. The method also includes receiving a control message and modifying elements of the control message while copying other elements in the control message and forwarding the control message between the self-backhauled base station and the second S-GW or MME node.

Claims

1-22. -22. (canceled)

23. A method for sending packets to a user equipment (UE) implemented in a system that includes a self-backhauled base station which communicates via a radio interface with an anchor base station, wherein the anchor base station communicates with a serving gateway (S-GW) of a cellular network or a Mobility Management Entity (MME) node of the UE via a transport network, wherein the S-GW comprises a second S-GW and wherein the self-backhauled base station is accessible by the second S-GW or MME node via a first S-GW that serves—

the self-backhauled base station, the method comprising;

receiving, at the second S-GW, the packets destined for the UE, served by the self-backhauled base station;

classifying, at the second S-GW, the packets to one or more bearers associated with the UE served by the self-backhauled base station;

encapsulating, at the second S-GW, the packets for transmission over a General Packet Radio Service (GPRS) Tunneling Protocol (GTP) tunnel to the self-backhauled base station;

sending, from the second S-GW, the packets to an Internet Protocol (IP) address associated with the self-backhauled base station;

receiving, at the first S-GW, the packets, wherein the IP address associated with the self-backhauled base station is associated with the first S-GW;

classifying, at the first S-GW, the packets to one or more bearers of the self-backhauled base station;

encapsulating, at the first S-GW, the packets to a General Packet Radio Service (GPRS) Tunneling Protocol (GTP) tunnel towards the anchor base station;

sending, from the first S-GW, the packets to the anchor base station;

receiving, at the anchor base station, the packets sent from the first S-GW;

decapsulating, at the anchor base station, the packets received from the first S-GW;

mapping, at the anchor base station, the decapsulated packets to the one or more bearers of the self-backhauled base station;

sending, from the anchor base station, the decapsulated packets to the self-backhauled base station on a radio interface;

receiving, at the self-backhauled base station, the packets sent from the anchor base station;

mapping, at the self-backhauled base station, the packets received from the anchor base station to the one or more bearers of the UE; and

sending, from the self-backhauled base station, the packets received from the anchor base station on a radio interface to the UE.

24. The method of claim 23, wherein the first S-GW is integrated into the anchor base station.

25. The method of claim 23, wherein the first S-GW maps the packets to the one or more bearers of the self-backhauled base station based on:

different IP addresses used by the self-backhauled base station for different self-backhauled bearers;

transport network Quality of Service (QoS) indicators contained in headers of the packets;

a UE bearer identified by looking into an inner tunneling header in the packets;

or

tunneling between the second S-GW of the UE and the first S-GW of the self-backhauled base station.

26. The method of claim 23, wherein the second S-GW of the UE indicates in the packets sent to the self-backhauled base station a self-backhauled bearer that the packets should be mapped to in the first S-GW of the self-backhauled base station, wherein the indication is achieved by:

using a different IP address of the self-backhauled base station for each self-backhauled bearer of the one or more bearers;

using transport network Quality of Service (QoS) indicators contained in headers of the packets;

or using tunneling between the second S-GW of the UE and the first S-GW of the self-backhauled base station.

27. The method of claim 26, where the self-backhauled base station indicates for the second S-GW of the UE which bearer of the one or more bearers the second S-GW of the UE should use for a UE bearer by:

indicating an IP address corresponding to a self-backhauled bearer of the one or more bearers;

or indicating the transport network QoS indicator corresponding to the self-backhauled bearer.

28. The method of claim 23, wherein the one or more bearers of the self-backhauled base station are established during a configuration and initial setup of the self-backhauled base station.

29. An anchor base station for use in a system that includes a self-backhauled base station that communicates via a radio interface with the anchor base station, wherein the anchor base station is arranged to communicate with a cellular network'"'"'s serving gateway (S-GW) or Mobility Management Entity (MME) node of a user equipment via a transport network, wherein the S-GW comprises a second S-GW, wherein the self-backhauled base station is accessible by the second S-GW or MME node via the anchor base station and wherein the anchor base station is operable to:

act as a proxy between the second S-GW or MME node and the self-backhauled base station by translating control plane messages and by switching data packets resulting in the user equipment appearing to the second S-GW and the MME node as being directly connected to the anchor base station such that the self-backhauled base station is hidden from the second S-GW and MME node;

receive a data packet destined for the user equipment;

map the received data packet from an incoming General Packet Radio Service (GPRS) Tunneling Protocol (GTP) tunnel to an outgoing GTP tunnel;

receive a control message and modify elements of the control message while copying other elements in the control message by modifying a user equipment connection identifier or translating a setup of a bearer for the user equipment to a bearer towards the self-backhauled base station; and

forward the modified control message between the self-backhauled base station and the second S-GW or MME node.

30. A method implemented in an anchor base station configured in a system that includes a self-backhauled base station that communicates via a radio interface with the anchor base station, wherein the anchor base station communicates with a cellular network'"'"'s serving gateway (S-GW) or Mobility Management Entity (MME) node of a user equipment via a transport network, wherein the S-GW comprises a second S-GW, and wherein the self-backhauled base station is accessible by the second S-GW or MME node via the anchor base station, comprising:

performing a proxy operation at the anchor base station, wherein the anchor base station acts as a proxy between the second S-GW or MME node and the self-backhauled base station by translating control plane messages and by switching data packets resulting in the user equipment appearing to the second S-GW and the MME node as being directly connected to the anchor base station such that the self-backhauled base station is hidden from the second S-GW and MME node;

receiving a data packet destined for the user equipment;

mapping the received data packet from an incoming General Packet Radio Service (GPRS) Tunneling Protocol (GTP) tunnel to an outgoing GTP tunnel;

receiving a control message and modifying elements of the control message while copying other elements in the control message by modifying a user equipment connection identifier or translating a setup of a bearer for the user equipment to a bearer towards the self-backhauled base station; and

forwarding the control message between the self-backhauled base station and the second S-GW or MME node.

31. The method of claim 30, wherein the anchor base station performs a proxy operation by:

maintaining for a UE connection an S1-Control Plane (CP) connection toward the self-backhauled base station and another S1-CP connection toward the MME node; and

mapping UE connection identifiers.

32. The method of claim 30, wherein the anchor base station performs a proxy operation by:

maintaining for a UE bearer connection a GTP tunnel towards the self-backhauled base station and another GTP tunnel towards the second S-GW; and

mapping between the two tunnel connections.

33. The method of claim 32, wherein the anchor base station creates a mapping table of GTP tunnels or UE connection identifiers at the time when UE bearers are established.