DOWNLINK TRANSMISSION IN A RAN INACTIVE MODE

• US 20180368196A1
• Filed: 05/22/2018
• Published: 12/20/2018
• Est. Priority Date: 06/16/2017
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: GAGE, William Anthony
• Granted Patent: US 10,820,192 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 9/0816 Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04W 12/03 Protecting confidentiality, e.g. by encryption
• CPC Class Codes: H04W 12/041 Key generation or derivation
• CPC Class Codes: H04W 12/69 Identity-dependent
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 68/04 multi-step notification using statistical or historical mobility data
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 76/11 Allocation or use of connection identifiers
• CPC Class Codes: H04W 76/12 Setup of transport tunnels
• CPC Class Codes: H04W 76/19 Connection re-establishment
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A network node of a Radio Access network (RAN) is configured for delivering downlink data to a user equipment (UE) operating in an inactive mode. The network node receives, via a network interface, downlink data destined for the UE and constructs a downlink protocol data unit (PDU) comprising the downlink data. The network node identifies a set of one or more target nodes within a RAN notification area, and transmits the downlink PDU and an inactive mode identifier associated with the UE to the identified set of target nodes using UE context information associated with the UE. One or more of the target nodes forwards the downlink PDU to the UE using delivery information provided by the network node.

Claims

1. A method at a network node of a radio access network (RAN) for delivering downlink data to a user equipment (UE) operating in an inactive mode, the method comprising:

receiving, via a network interface of the network node, the downlink data destined to the UE;

retrieving stored UE context information and an inactive mode identifier associated with the UE;

constructing a downlink protocol data unit (PDU) using the stored UE context information, the downlink PDU including the received downlink data;

identifying one or more target nodes using the stored UE context information; and

transmitting, via the network interface, the inactive mode identifier and the downlink PDU to the identified one or more target nodes to cause at least one of the identified one or more target nodes to transmit the downlink PDU to the UE.

2. The method as claimed in claim 1, wherein each one of identified one or more target nodes is configured to control communication within at least one cell of the RAN.

3. The method as claimed in claim 2, wherein identifying the one or more target nodes comprises:

identifying cells of the RAN in which the UE may be located, based on the stored UE context information; and

selecting nodes of the RAN configured to control communication within the identified cells as the target nodes.

4. The method as claimed in claim 2, wherein the stored UE context information comprises information identifying a RAN notification area associated with the UE.

5. The method as claimed in claim 4, wherein identifying the one or more target nodes comprises selecting nodes of the RAN configured to control communication within the identified RAN notification area as the target nodes.

6. The method as claimed in claim 1, wherein the stored UE context information comprises at least one cryptographic key, and wherein constructing the downlink PDU comprises cryptographically securing the downlink PDU using the at least one cryptographic key.

7. The method as claimed in claim 6, wherein cryptographically securing the downlink PDU comprises either one or both of:

encrypting the downlink PDU using the at least one cryptographic key; and

computing a message integrity check value using the downlink PDU and the at least one cryptographic key.

8. The method as claimed in claim 1, wherein causing at least one of the identified one or more target nodes to transmit the downlink PDU to the UE comprises causing at least one of the identified one or more target nodes to transmit a downlink transmission notification comprising one or more of:

the inactive mode identifier, a preamble identifier, and an ephemeral device identifier associated with the UE.

9. The method as claimed in claim 8, wherein the downlink transmission notification comprises the preamble identifier, and wherein causing at least one of the identified one or more target nodes to transmit the downlink PDU to the UE further comprises causing at least one of the one or more target nodes to:

receive, following transmission of the downlink transmission notification, a preamble associated with the preamble identifier; and

at least partially in response to receipt of the preamble associated with the preamble identifier, transmit the downlink PDU.

10. The method as claimed in claim 8, wherein the downlink transmission notification comprises the ephemeral device identifier, and wherein causing at least one of the identified one or more target nodes to transmit the downlink data PDU to the UE further comprises causing at least one of the one or more target nodes to:

transmit, following transmission of the downlink transmission notification, the downlink PDU in association with the ephemeral device identifier.

11. The method as claimed in claim 1, wherein transmitting the downlink PDU to the identified one or more target nodes further comprises transmitting delivery instructions to the identified one or more target nodes.

12. The method as claimed in claim 11, wherein the delivery instructions comprise a user device paging identifier associated with the UE, and wherein causing at least one of the identified one or more target nodes to transmit the downlink PDU to the UE comprises causing at least one of the identified one or more target nodes to transmit a downlink transmission notification comprising the user device paging identifier.

13. The method as claimed in claim 11, wherein the delivery instructions comprise one or more conditions to cause at least one of the one or more target nodes to transmit a delivery status report to the network node.

14. The method as claimed in claim 13, wherein the one or more conditions comprise any one or more of:

successful delivery of the downlink PDU;

no response to a downlink transmission notification;

downlink data transmission failure over a radio link to the UE; and

downlink data transmission attempted over a radio link to the UE.

15. The method of claim 1, wherein constructing the downlink PDU further comprises incorporating an indication into the downlink PDU to cause the UE to transmit an acknowledgement to the network node.

16. A network function comprising:

a network interface configured to receive data from and transmit data to other network functions connected to a network;

at least one processor; and

a non-transient computer readable memory storing software instructions configured to control the at least one processor to implement a process comprising;

receiving, via the network interface, downlink data destined for a user equipment (UE), the UE operating in an inactive mode;

retrieving stored UE context information and an inactive mode identifier associated with the UE;

constructing a downlink protocol data unit (PDU) using the stored UE context information, the downlink PDU including the received downlink data;

identifying one or more target nodes using the stored UE context information; and

transmitting the inactive mode identifier and the downlink PDU to the identified one or more target nodes, to cause at least one of the identified one or more target nodes to transmit the downlink PDU to the UE.

17. The network function as claimed in claim 16, wherein each one of identified one or more target nodes is configured to control communication within at least one cell of the RAN.

18. The network function as claimed in claim 16, wherein identifying the one or more target nodes comprises:

identifying cells of the RAN in which the UE may be located, based on the stored UE context information; and

selecting nodes of the RAN configured to control communication within the identified cells as the target nodes.

19. The network function as claimed in claim 16, wherein the stored UE context information comprises information identifying a RAN notification area associated with the UE,

20. The network function as claimed in claim 16, wherein identifying the one or more target nodes comprises selecting nodes of the RAN configured to control communication within the identified RAN notification area as the target nodes.

21. The network function as claimed in claim 16, wherein the stored UE context information comprises at least one cryptographic key, and wherein constructing the downlink PDU comprises cryptographically securing the downlink PDU using the at least one cryptographic key

22. A network function comprising:

a network interface configured to receive data from and transmit data to other network functions connected to a network;

at least one processor;

a radio receiver configured to receive data through a radio link;

a radio transmitter configured to transmit data through the radio link; and

a non-transient computer readable memory storing software instructions configured to control the at least one processor to implement a process comprising;

receiving, via the network interface, a data delivery request comprising;

an inactive mode identifier associated with a user equipment (UE); and

a downlink PDU destined for the UE, the UE operating in an inactive mode; and

transmitting via the radio transmitter a downlink transmission notification comprising one or more of;

the inactive mode identifier, a preamble identifier, an ephemeral device identifier associated with the UE, and a user device paging identifier associated with the UE.

23. The network function as claimed in claim 22, wherein the non-transient computer readable memory further stores software instructions configured to control the at least one processor to implement steps of:

receiving, via the radio receiver, a preamble associated with the preamble identifier; and

at least partially in response to receiving the preamble, transmitting via the radio transmitter the downlink PDU.