Handover method with link failure recovery, wireless device and base station for implementing such method

Patent metadata

Field	Value
Publication number	US-2016192253-A1
Application number	US-201615065419-A
Country	US
Kind code	A1
Filing date	Mar 9, 2016
Priority date	Aug 12, 2007
Publication date	Jun 30, 2016
Grant date	—

Abstract

For each target cell determined by a handover decision process, a first message is transmitted from a source base station ( 20 S) to a target base station ( 20 T) servicing that target cell. The first message includes an identifier of a wireless device ( 10 ) having a communication link with the source base station and information for obtaining authentication data for this wireless device. The authentication data depends on a secret key available to the wireless device and the source base station and on an identity of the target cell. Upon failure of the communication link, a cell is selected at the wireless device, which transmits to that cell a reestablishment request message including its identifier and authentication data depending on the secret key and on an identity of the selected cell. If the selected cell is a target cell serviced by a target base station that received a first message, conformity of the authentication data included in the reestablishment request message with the authentication data obtained from this first message is verified to authorize transfer of the communication link to the selected cell.

First claim

1 . (canceled)

2 . A method of communicating with a network in a wireless communication system, the method performed by a user equipment (UE) and comprising:
detecting a radio link failure; performing cell selection upon detection of the radio link failure; and transmitting a message to request a connection re-establishment to the network, wherein the message includes an identifier of the UE and an authentication vector depending on a shared key available to the UE and the network and on an identity of a selected cell, and wherein the authentication vector is to be used for verifying the UE at the selected cell.

3 . The method according to claim 2 , wherein the identifier of the UE is a cell-radio network temporary identifier (C-RNTI) and the message is an Radio Resource Control (RRC) connection reestablishment request message.

4 . The method according to claim 2 , wherein the C-RNTI is a C-RNTI used in a source cell.

5 . The method according to claim 2 , wherein the shared key is used for the protection of RRC traffic.

6 . The method according to claim 5 , wherein the shared key is derived from a high level secret key.

7 . The method according to claim 6 , wherein the shared key is a K RRCint key and the high level secret key is a K eNB key which is available to both the UE and an eNodeB.

8 . The method according to claim 2 , wherein the authentication vector further depends on a common time reference between the UE and at least one base station.

9 . The method according to claim 8 , wherein the authentication vector is calculated using a cryptographic algorithm based on input parameters including the secret key, the identity of the selected cell and the common time reference.

10 . The method according to claim 2 , wherein the authentication vector is a message authentication code for integrity (MAC-I).

11 . A user equipment (UE) for communicating with a network in a wireless communication system, the UE comprising:
a transmitter; and a controller configured to control the transmitter for communicating with the network, wherein the UE is configured to: detect a radio link failure; perform cell selection upon detection of the radio link failure; and transmit a message to request a connection re-establishment to the network by controlling the transmitter, wherein the message includes an identifier of the UE and an authentication vector depending on a shared key available to the UE and the network and on an identity of a selected cell, and wherein the authentication vector is to be used for verifying the UE at the selected cell.

12 . The UE according to claim 11 , wherein the identifier of the UE is a cell-radio network temporary identifier (C-RNTI) and the message is an Radio Resource Control (RRC) connection reestablishment request message.

13 . The method according to claim 11 , wherein the C-RNTI is a C-RNTI used in a source cell.

14 . The method according to claim 11 , wherein the shared key is used for the protection of RRC traffic.

15 . The method according to claim 14 , wherein the shared key is derived from a high level secret key.

16 . The method according to claim 15 , wherein the shared key is a K RRCint key and the high level secret key is a K eNB key which is available to both the UE and an eNodeB.

17 . The method according to claim 11 , wherein the authentication vector further depends on a common time reference between the UE and at least one base station.

18 . The method according to claim 17 , wherein the authentication vector is calculated using a cryptographic algorithm based on input parameters including the secret key, the identity of the selected cell and the common time reference.

19 . The method according to claim 11 , wherein the authentication vector is a message authentication code for integrity (MAC-I).

Assignees

• Lg Electronics Inc

Inventors

• Fischer Patrick

Classifications

• H04W28/0278

  using buffer status reports (dynamic wireless traffic scheduling definition H04W72/12) · CPC title

• H04W36/0094 Primary

  Definition of hand-off measurement parameters · CPC title

• H04L69/04 Primary

  Protocols for data compression, e.g. ROHC · CPC title

• H04L47/38

  by adapting coding or compression rate · CPC title

• H04W72/52

  based on load · CPC title