Network-Assisted Cell Selection at Connection Re-establishment

• US 20150092686A1
• Filed: 05/28/2014
• Published: 04/02/2015
• Est. Priority Date: 08/09/2013
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Cui, Tao, Xuan, Zhiyi, Mller, Walter
• Granted Patent: US 9,961,607 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 36/305 Handover due to radio link failure control signalling for hand-off failure H04W36/0079
• CPC Class Codes: H04W 36/36 by user or terminal equipment
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 76/19 Connection re-establishment

Abstract

According to several disclosed techniques, a wireless network provides assistance information to a mobile terminal for cell selection at re-establishment of a connection after a radio link failure. An example method is implemented in a mobile terminal served in a first cell of a wireless network, and includes receiving (510) a configuration message from the network, the configuration message identifying at least one carrier frequency. Upon subsequently losing connection with the first cell without receiving a handover command, the mobile terminal initiates (520) a cell search using the identified at least one carrier frequency, based on the configuration message.

Claims

1-41. -41. (canceled)

42. A method in a mobile terminal for controlling connection re-establishment between said mobile terminal and a wireless communication network, said mobile terminal being served in a first cell of said network, the method comprising:

receiving a configuration message from the network, the configuration message identifying at least one carrier frequency; and

,

upon subsequently losing connection with the first cell without receiving a handover command, initiating a cell search using the at least one carrier frequency.

43. The method of claim 42, wherein the configuration message indicates that one or more first carrier frequencies are to be searched, and wherein initiating the cell search comprises searching for the indicated one or more first carrier frequencies, based upon the configuration message.

44. The method of claim 42, wherein the configuration message indicates that one or more second carrier frequencies are not to be searched, and wherein initiating the cell search comprises searching only for carrier frequencies other than the indicated one or more second carrier frequencies, based on the configuration message.

45. The method of claim 42, wherein the configuration message is received via a first radio access technology (RAT) and further includes an indication that cell search should begin with an alternative RAT, and wherein initiating the cell search comprises beginning the cell search by searching for one or more carrier frequencies of an alternative RAT, based upon the indication.

46. The method of claim 45, wherein the configuration message further includes one or more third carrier frequencies corresponding to the alternative RAT, and wherein initiating the cell search comprises beginning the cell search by searching for one or more of the third carrier frequencies, based on the configuration message.

47. The method of claim 45, wherein the configuration message further includes an identifier of the alternative RAT, and wherein initiating the cell search comprises beginning the cell search by searching for a carrier frequency of the identified alternative RAT.

48. A method, in a wireless network node, for controlling connection re-establishment between a mobile terminal and a wireless communication network, the method comprising:

establishing a connection with the mobile terminal; and

,

prior to an initiation of a handover of the mobile terminal by the wireless network node, sending a configuration message to the mobile terminal, the configuration message identifying at least one carrier frequency for use by the mobile terminal in initiating a cell search upon losing connection with the wireless communication network.

49. The method of claim 48, wherein the configuration message indicates that one or more first carrier frequencies are to be searched in a cell search initiated upon losing connection with the wireless communication network.

50. The method of claim 48, wherein the configuration message indicates that one or more second carrier frequencies are not to be searched in a cell search initiated upon losing connection with the wireless communication network.

51. The method of claim 48, wherein the configuration message is received via a first radio access technology (RAT) and further includes an indication that a cell search initiated upon losing connection with the wireless communication network should begin with an alternative RAT.

52. The method of claim 51, wherein the configuration message further includes one or more third carrier frequencies corresponding to the alternative RAT.

53. The method of claim 51, wherein the configuration message further includes an identifier of the alternative RAT.

54. The method of claim 48, wherein the method further comprises first preparing at least one list of carrier frequencies for each of one or more cells, based on frequency relations for each cell obtained from statistical records or configuration information, wherein the configuration message is based on the at least one list corresponding to the cell serving the mobile terminal.

55. A mobile terminal comprising a radio transceiver circuit configured to communicate with a wireless communication network and a processing circuit configured to control the radio transceiver circuit, wherein the processing circuit is further configured to:

receive a configuration message from the network, via the radio transceiver circuit, the configuration message identifying at least one carrier frequency; and

,

upon subsequently losing connection with the first cell without receiving a handover command, initiate a cell search using the at least one carrier frequency.

56. The mobile terminal of claim 55, wherein the configuration message indicates that one or more first carrier frequencies are to be searched, and wherein the processing circuit is configured to initiate the cell search by searching for the indicated one or more first carrier frequencies, based on the configuration message.

57. The mobile terminal of claim 55, wherein the configuration message indicates that one or more second carrier frequencies are not to be searched, and wherein the processing circuit is configured to search only for carrier frequencies other than the indicated one or more second carrier frequencies, based on the configuration message.

58. The mobile terminal of claim 55, wherein the processing circuit is configured to receive the configuration message via a first radio access technology (RAT) wherein the configuration message further includes an indication that cell search should begin with an alternative RAT, and wherein the processing circuit is configured to begin the cell search by searching for one or more carrier frequencies of an alternative RAT, based on the indication.

59. The mobile terminal of claim 58, wherein the configuration message further includes one or more third carrier frequencies corresponding to the alternative RAT, and wherein the processing circuit is configured to begin the cell search by searching for one or more of the third carrier frequencies, based on the configuration message.

60. The mobile terminal of claim 59, wherein the configuration message further includes an identifier of the alternative RAT, and wherein the processing circuit is configured to begin the cell search by searching for a carrier frequency of the identified alternative RAT, based on the configuration message.

61. A wireless network node, comprising an interface circuit configured to communicate with a mobile terminal and for communication with one or more other wireless network nodes, and a processing circuit configured to control the radio transceiver circuit and the communications interface circuit, wherein the processing circuit is further configured to:

establish a connection with the mobile terminal, using the radio transceiver; and

,

prior to an initiation of a handover of the mobile terminal by the wireless network node, send a configuration message to the mobile terminal via the radio transceiver, the configuration message identifying at least one carrier frequency for use by the mobile terminal in initiating a cell search upon losing connection with the wireless communication network.

62. The wireless network node of claim 61, wherein the configuration message indicates that one or more first carrier frequencies are to be searched in a cell search initiated upon losing connection with the wireless communication network.

63. The wireless network node of claim 61, wherein the configuration message indicates that one or more second carrier frequencies are not to be searched in a cell search initiated upon losing connection with the wireless communication network.

64. The wireless network node of claim 61, wherein the processing circuit is configured to send the configuration message via a first radio access technology (RAT) and wherein the configuration message further includes an indication that a cell search initiated upon losing connection with the wireless communication network should begin with an alternative RAT.

65. The wireless network node of claim 64, wherein the configuration message further includes one or more third carrier frequencies corresponding to the alternative RAT.

66. The wireless network node of claim 64, wherein the configuration message further includes an identifier of the alternative RAT.

67. The wireless network node of claim 61, wherein the processing circuit is further configured to first prepare at least one list of carrier frequencies for each of one or more cells, based on frequency relations for each cell obtained from statistical records or configuration information, and to form the configuration message based on the at least one list corresponding to the cell serving the mobile terminal.