Power Control in a Local Network Node (Lln)

• US 20080069028A1
• Filed: 08/01/2005
• Published: 03/20/2008
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: Airvana Corporation (CommScope Holding Company, Inc.)
• Inventors: Richardson, Andrew
• Granted Patent: US 8,290,527 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04B 17/26 using historical data, averaging values or statistics
• CPC Class Codes: H04B 17/327 Received signal code power [RSCP]
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 52/247 where the output power of a terminal is based on a path parameter sent by another terminal
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 84/105 PBS [Private Base Station] network H04W84/12 - H04W84/16 take precedence

Abstract

The invention relates to a method and system of setting transmitter power levels, particularly in a Local Network Node transmitter, providing a pico cell for private use. A User Equipment (UE) is used to make measurements of the transmission link properties, such as downlink power and round trip time. Based on the measurements made at one or a plurality of locations, the power of the Local Network Node can be determined such that interference is minimised with any overlying cells of a macro-network. Call handovers between the UE and the cell of a macro network can also be arranged based on properties measure by the UE

Claims

1-49. -49. (canceled)

50. A local network node for providing a user equipment with a local connection to a mobile network, the network having one or more cells overlapping the coverage area of the local network node, comprising:

a processor arranged to receive from the user equipment one or more parameters related to the power of the downlink between the user equipment and the local network node, measured by the user equipment at a plurality of locations within the desired coverage area of the local network node;

a measurement processor for determining a transmit power for the downlink between the local network node and the user equipment, based on the measured parameters, and the minimum required power for the correct reception of a downlink signal at the user equipment.

51. The local network node of claim 50, comprising a controller arranged to request that the user equipment measure one or more parameters related to the power of the downlink between the user equipment and the local network node, and transmit the measured parameters to the local network node.

52. The local network node of claim 51, wherein the controller is arranged to request that the user equipment measure the one or more parameters at the boundary of the desired coverage area for the local network node.

53. The local network node of claim 51, wherein the processor is configured to detect a code dialed by the operator of a user equipment, and if detected, the controller requests that the user equipment measure the one or more parameters.

54. The local network node of claim 51, wherein the controller is arranged to request that the connection between the user equipment and the local network node be configured as a full duplex connection, with a constant data rate, and a constant transmit power for both the user equipment and the local network node.

55. The local network node of claim 51, wherein the controller is arranged to request that the user equipment measure one or more of:

the downlink received signal code power, the downlink Ec/Io measurement (where Ec is the energy per chip, Io is the interference), the downlink path loss and the UE transmit power.

56. The local network node of claim 51, wherein the measurement processor is arranged to determine the minimum signal power received by the user equipment at the plurality of locations, and determine the transmit power for the downlink as the minimum transmit power that would allow a signal to be received at the plurality of locations with the minimum required power.

57. The local network node of claim 51, wherein the measurement processor is arranged to determine the transmit power based on the average received signal code power measured at the plurality of locations, and a factor k derived from the link budget analysis of the downlink, the fading margins required to give a predetermined outage probability based on the number of measurements.

58. The local network node of claim 51, wherein the controller is arranged to set the transmit power in dependence on the result of the measurement processor determination.

59. The local network node of claim 51, wherein the controller is arranged to request that the user equipment measure at least the downlink received signal code power, and the processor of the LNN is arranged to measure the uplink signal code power, the transmit power being determined on the basis of both of the uplink and downlink signal power.

60. The local network node of claim 51, wherein the controller is arranged to request at intervals that the user equipment measure the one or more parameters, and the measurement processor determine the transmit power;

wherein the controller is arranged to set the transmit power in dependence on the determination of the measurement processor.

61. The local network node of claim 60, wherein the controller is arranged to request that the processor measure one or more parameters of the uplink between the user equipment and the local network node, and control the measurement processor in dependence on the one or more uplink parameters.

62. The local network node of claim 61, wherein the one or more parameters include the return trip time (RTT).

63. The local network node of claim 62, wherein the measurement processor is controlled to disregard power measurements of the downlink, when the return trip time indicates that the user equipment is more than a predetermined distance from the local network node.

64. The local network node of claim 60, wherein the controller is arranged to request GPS position information from the user equipment, and wherein the measurement processor is controlled to disregard power measurements of the downlink, when the GPS information indicates that the user equipment is more than a predetermined distance from the local network node.

65. A local network node for providing a user equipment with a local connection to a mobile network, the network having one or more cells overlapping the coverage area of the local network node, comprising:

a processor function arranged to;

receive from the user equipment one or more parameters related to the power of the downlink between the user equipment and the local network node; and

receive from the user equipment one or more parameters related to the noise and interference on the downlink as a result of overlapping cells of the network and any other competing local network nodes; and

a measuring processor for determining a transmit power for the downlink between the local network node and the user equipment, based on the received parameters, and the minimum required power for the correct reception of a downlink signal at the user equipment.

66. The local network node of claim 65, wherein the parameters related to the noise and interference on the downlink include the received signal code power, measured at the user equipment, for overlapping cells in the network and any competing local network nodes.

67. The local network node of claim 65, wherein the measuring processor uses the measured parameters related to the power to determine constants relating the radiation power of the transmitting antenna and the received power from the antenna, and the path loss exponent.

68. The local network node of claim 66, wherein the measurement processor determines the required transmit power based on the expression:

69. The local network node of claim 65, comprising a controller arranged to request that the user equipment measure the one or more parameters related to the power of the downlink, as well as the one or more parameters related to the noise or interference on the downlink.

70. A local network node for providing a user equipment with a local connection to a mobile network, the network having one or more cells overlapping the coverage area of the local network node, comprising:

a processor arranged to receive from the user equipment one or more parameters describing the downlink between the user equipment and the local network node, and/or to measure one or more parameters of the uplink between the user equipment and the local network node;

a measuring processor for determining from the parameters an estimate of the quality of the downlink or of the uplink between the local network node and the user equipment;

a controller for transmitting an indication to the user equipment that a handover is likely to occur, based on the estimate of the quality of the downlink or the uplink;

wherein the controller is arranged to receive a signal from the user equipment indicating whether a handover is desired, and control the handover in dependence on the received signal.

71. The local network node of claim 70, wherein the one or more parameters include the downlink transmit power level, uplink signal level, downlink signal level estimates, uplink signal quality estimates, downlink signal quality estimates, uplink path loss estimates, downlink path loss estimates, round-trip-time estimates and position location estimates.

72. The local network node of claim 70, comprising a DTMF tone generator, and wherein the controller is arranged to transmit the indication to the user equipment by DTMF tone.

73. The local network node of claim 70, comprising an SMS message generator, and wherein the controller is arranged to transmit the indication to the user equipment by SMS message.

74. A method of controlling the transmit power of the downlink between a local network node and a user equipment being provided with a local connection to a mobile network by the local network node, the network having one or more cells overlapping the coverage area of the local network node, comprising:

measuring, by means of the user equipment, one or more parameters related to the power of the downlink at a plurality of locations within the coverage area of the local network node;

transmitting the one or more measured parameters to the local network node;

determining a transmit power for the downlink between the local network node and the user equipment, based on the measured parameters, and the minimum required power for the correct reception of a downlink signal at the user equipment.

75. The method of claim 74, comprising transmitting a request from the local network node to the that the user equipment instructing it to measure one or more parameters related to the power of the downlink between the user equipment and the local network node, and transmit the measured parameters to the local network node.

76. The method of claim 75, wherein measurements of the one or more parameters are made at the boundary of the desired coverage area for the local network node.

77. The method of claim 75, comprising dialing a code, by means of the user equipment, to begin measurement of the one or more parameters.

78. The method of claim 75, comprising establishing a connection between the user equipment and the local network node that is a full duplex connection, with a constant data rate, and a constant transmit power for both the user equipment and the local network node.

79. The method of claim 75, wherein the user equipment measures one or more of:

the downlink received signal code power, the downlink Ec/Io measurement (where Ec is the energy per chip, Io is the interference) the downlink path loss and the UE transmit power,

80. The method of claim 75, wherein the determining step comprises determining the minimum signal power received by the user equipment at the plurality of locations, and determining the transmit power for the downlink as the minimum transmit power that would allow a signal to be received at the plurality of locations with the minimum required power.

81. The method of claim 75, wherein the determining step is arranged to determine the transmit power based on the average received signal code power measured at the plurality of locations, and a factor k derived from the link budget analysis of the downlink, the fading margins required to give a predetermined outage probability based on the number of measurements.

82. The method of claim 75, comprising:

making the one or more measurements at intervals, by means of the user equipment;

determining the transmit power; and

setting the transmit power at intervals in dependence on the determination.

83. The method of claim 75, comprising transmitting a request to the user equipment to cause it to measure at least the downlink received signal code power, measuring the uplink signal code power, and determining the transmit power on the basis of both of the uplink and downlink signal power.

84. The method of claim 83, comprising measuring at the local network node one or more parameters of the uplink between the user equipment and the local network node, and processing the one or more measured downlink parameters in dependence on the one or more uplink parameters.

85. The method of claim 84, wherein the one or more parameters include the return trip time (RTT).

86. The method of claim 85, wherein in the determining step power measurements of the downlink are disregarded when the return trip time indicates that the user equipment is more than a predetermined distance from the local network node.

87. The method of claim 84, comprising transmitting GPS position information describing the location of the user equipment, and wherein in the determining step power measurements of the downlink are disregarded when the GPS position information indicates that the user equipment is more than a predetermined distance from the local network node.

88. A method of controlling the transmit power of the downlink between a local network node and a user equipment being provided with a local connection to a mobile network by the local network node, the network having one or more cells overlapping the coverage area of the local network node, comprising:

measuring, by means of the user equipment, one or more parameters related to the power of the downlink between the user equipment and the local network node;

measuring, by means of the user equipment, one or more parameters related to the noise and interference on the downlink as a result of overlapping cells of the network and any other competing local network nodes;

transmitting the measured parameters to the local network node; and

determining a transmit power for the downlink between the local network node and the user equipment, based on the measured parameters, and the minimum required power for the correct reception of a downlink signal at the user equipment.

89. The method of claim 88, wherein the parameters related to the noise and interference on the downlink include the received signal code power measured at the user equipment for overlapping cells in the network and any competing local network nodes.

90. The method of claim 88, wherein the determining step comprises using the measured parameters related to the power to determine constants related to the power to determine constants relating the radiation power of the transmitting antenna and the received power from the antenna, and the path loss exponent.

91. The method of claim 90, wherein in the determining step required transmit power is determined based on the expression:

92. The method of claim 88, comprising transmitting a request from the local network node to the user equipment instructing the user equipment to measure the one or more parameters related to the power of the downlink, as well as the one or more parameters related to the noise or interference on the downlink.

93. A method of controlling the handover of user equipment being provided with a local connection to a mobile network by the local network node, from the local network node to the network, the network having one or more cells overlapping the coverage area of the local network node, comprising:

measuring by means of the user equipment one or more parameters describing the downlink between the user equipment and the local network node, and transmitting these to the local network node; and

/or

measuring by means of the local network node, one or more parameters of the uplink between the user equipment and the local network node;

determining from the parameters an estimate of the quality of the downlink or of the uplink between the local network node and the user equipment;

transmitting an indication to the user equipment that a handover is likely to occur, based on the estimate of the quality of the downlink or the uplink;

receiving a signal from the user equipment indicating whether a handover is desired; and

controlling the handover in dependence on the received signal.

94. The method of claim 93, wherein the one or more parameters include the downlink transmit power level, uplink signal level downlink transmit, downlink signal level estimates, uplink signal quality estimates, downlink signal quality estimates, uplink path loss estimates, downlink path loss estimates, round-trip-time estimates and position location estimates.

95. The method of claim 93, comprising transmitting the indication to the user equipment by generating a DTMF tone and including this in an active call.

96. The method of claim 93 comprising transmitting the indication to the user equipment by SMS message.