Reducing interference in cellular mobile communication networks

• US 20030186653A1
• Filed: 03/18/2003
• Published: 10/02/2003
• Est. Priority Date: 05/14/1998
• Status: Active Grant

• Current Assignee: Behzad Mohebbi, Michael John Shearme
• Original Assignee: Behzad Mohebbi, Michael John Shearme
• Inventors: Mohebbi, Behzad, Shearme, Michael John
• Granted Patent: US 6,925,303 B2
• Time in Patent Office: Days
• US Class Current: 455/67.11
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/20 for optimising the interference level
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/36 by user or terminal equipment
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/12 Access point controller devices

Abstract

In a cellular mobile communications network a mobile station is capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel. A transmission property of the downlink signals from the plurality of base stations to the mobile station is measured, and decided, in dependence upon the measure of the transmission property, a preferred base station transmitting the downlink signal with a preferred transmission property among the plurality of the base stations. The mobile station includes, in the uplink signal, data indicating the preferred base station(s) for transmitting the subsequent downlink signal to the mobile station. The base stations receiving the uplink signal identify from the data the preferred based station(s) and only the base station(s) identified as the preferred base station(s) transmits a subsequent downlink signal to the mobile station. Interference in such a cellular mobile telecommunications network can therefore be reduced.

Claims

1. A cellular mobile communications network in which a mobile station is capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel, comprising:

a monitoring means for measuring a transmission property of the downlink signals from the plurality of base stations to the mobile station; and

a comparison means for deciding, in dependence upon the measure of the transmission property, a preferred base station transmitting the downlink signal with a preferred transmission property among the plurality of the base stations.

2. The network of claim 1, wherein said mobile station includes said monitoring means and said comparison means.

3. The network of claim 2, wherein said comparison means is operable to include, in the uplink signal, data indicating the preferred base station for transmitting the subsequent downlink signal to the mobile station.

4. The network of claim 1, further comprising an identification means for identifying, among the plurality of base stations, the preferred base station as decided by said comparison means.

5. The network of claim 4, wherein each base station includes said identification means and said mobile station includes said comparison means, and wherein said comparison means is operable to include, in the uplink signal, data indicating the preferred base station for transmitting the subsequent downlink signal to the mobile station.

6. The network of claim 1, wherein the transmission property of the downlink signals from the plurality of base stations to the mobile station is represented by power levels of the received downlink signals.

7. The network of claim 1, wherein said identification means further selects a base station, among the plurality of base stations, to transmit a subsequent downlink signal to the mobile station responsive to the identification of the preferred base station.

8. A cellular mobile communications network, comprising:

a plurality of base stations each of which is capable of transmitting a downlink signal to a mobile station and receiving an uplink signal from the mobile station through a wireless channel, each base station including;

an identification means for identifying, among the plurality of base stations, a base station for transmitting a subsequent downlink signal to the mobile station upon receiving an uplink signal indicating a preferred base station, said preferred base station being determined in accordance with a measured transmission property of the downlink signals from said plurality of base stations; and

a base station controller, operatively connected to said plurality of base stations for delivering the downlink signals to said plurality of base stations for further transmission therefrom.

9. The network of claim 8, wherein each base station of said plurality of base stations further includes a switching means for preventing from transmitting a subsequent downlink signal to the mobile station unless the base station is identified as said base station for transmitting the subsequent downlink signal to the mobile station, among the plurality of the base stations.

10. The network of, claim 8, wherein the transmission property of the downlink signals from the plurality of base stations to the mobile station is represented by power levels of the received downlink signals.

11. A cellular mobile communications network, comprising:

a plurality of base stations each of which is capable of transmitting a downlink signal to a mobile station and receiving an uplink signal from the mobile station through a wireless channel, each base station including;

a disabling means for preventing the base station from transmitting a subsequent downlink signal to the mobile station unless the base station is identified, among the plurality of the base stations, as a transmitting base station, which identification occurs upon receiving an uplink signal, from the mobile station, indicating a preferred base station for transmitting a subsequent downlink signal, the preferred base station being determined responsive to a measured transmission property of the downlink signals; and

a base station controller, operatively connected to the plurality of base stations, for delivering the downlink signals to said plurality of base stations for further transmission therefrom.

12. The network of claim 11, wherein each of the plurality of base stations further includes an identification means for identifying, among the plurality of base stations, the transmitting base station for transmitting a subsequent downlink signal to the mobile station.

13. The network of claim 11, wherein the transmission property of the downlink signals from the plurality of base stations to the mobile station is represented by power levels of the received downlink signals.

14. A mobile station capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of the base stations through a wireless channel, comprising:

a monitoring means for producing a measure of a transmission property of the downlink signals from the plurality of base stations; and

a comparison means, in dependence upon the measure of the transmission property, for determining the preferred base station with the preferred property among the plurality of the base stations for transmitting the downlink signal.

15. The mobile station of claim 14, further comprising:

a transmission means for transmitting an uplink signal including data identifying, among the plurality of base stations, a preferred base station for transmitting a subsequent downlink signal.

16. The mobile station of claim 14, wherein the transmission property of the downlink signals from the plurality of base stations is represented by power levels of the received downlink signals.

17. A base station which supports a wireless channel for a mobile station together with one or more other base stations, comprising:

a transmission means for transmitting a downlink signal to the mobile station, the mobile station being capable of receiving downlink signals from the other base stations as well;

a receiving means for receiving an uplink signal from the mobile station; and

an identification means for identifying, when the base station receives from the mobile station an uplink signal indicating a preferred base station, from among the base stations, if the base station is the preferred base station for transmitting a subsequent downlink signal to the mobile station, said preferred base station being determined responsive to a measure of a transmission property of the downlink signals.

18. The base station of claim 17, further comprising:

a switching means for preventing the transmission of a subsequent downlink signal to the mobile station responsive to said identification means.

19. A base station which supports a wireless channel for a mobile station together with one or more other base stations, comprising:

a transmission means for transmitting a downlink signal to the mobile station, the mobile station being capable of receiving downlink signals from the other base stations as well;

a receiver means for receiving an uplink signal from the mobile station; and

a switching means for preventing the transmission of a subsequent downlink signal to the mobile station unless the base station is identified as a transmitting base station upon the base station receiving, from the mobile station, an uplink signal indicating a preferred base station, from among the base stations, for transmitting a subsequent downlink signal, said preferred base station being determined responsive to a measure of a transmission property of the downlink signals.

20. The base station of claim 19, further comprising:

an identification means for identifying if the base station is the transmitting base station for transmitting a subsequent downlink signal to the mobile station responsive to receiving the uplink signal indicating a preferred base station.

21. An electronics device for use in a mobile station, comprising:

a receiving means for receiving a downlink signal from each of a plurality of base stations;

a transmitting means for transmitting an uplink signal to the plurality of the base stations;

a measuring means for measuring a transmission property of the downlink signals from each of the plurality of base stations; and

a determining means, in dependence upon the measured transmission property, for determining a preferred base station among the plurality of base stations for transmitting the downlink signal.

22. The electronics device of claim 21, further comprising:

an identification means for including, in the uplink signal, data identifying a preferred base station, among the plurality of base stations, for transmitting a subsequent downlink signal.

23. The electronics device of claim 21, wherein the transmission property of the downlink signals from the plurality of base stations is represented by power levels of the received downlink signals.

24. Control circuitry, for use in a mobile station capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of the base stations through a wireless channel, said control circuitry comprising:

a measuring means for producing a measure of a transmission property of the downlink signals from the plurality of base stations; and

a determining means, in dependence upon the measure of the transmission property, for determining a preferred base station, among the plurality of base stations, for transmitting the downlink signal with the preferred property.

25. The control circuitry of claim 24, further comprising:

a transmission means for transmitting an uplink signal including data identifying a preferred base station, among the plurality of base stations, for transmitting a subsequent downlink signal.

26. The control circuitry of claim 24, wherein the transmission property of the downlink signals from the plurality of base stations is represented by power levels of the received downlink signals.

27. An electronics device for use in a base station which supports a wireless channel for a mobile station with one or more of other base stations, comprising:

a transmitter means for transmitting a downlink signal to the mobile station, the mobile station being capable of receiving downlink signals from the other base stations;

a receiving means for receiving an uplink signal from the mobile station; and

,

an identification means for identifying if the base station is a preferred base station, among the base stations, upon the base station receiving the uplink signal indicating the preferred base station for transmitting a subsequent downlink signal to the mobile station, said preferred base station being determined responsive to a measure of a transmission property of the downlink signals at the mobile station.

28. The electronics device of claim 27, further comprising:

a switching means for preventing the transmission of a subsequent downlink signal to the mobile station responsive to the identification means.

29. An electronics device for use in a base station which supports a wireless channel for a mobile station, comprising:

a transmission means for transmitting a downlink signal to the mobile station, the mobile station being capable of receiving downlink signals from each of a plurality of base stations;

a receiving means for receiving an uplink signal from the mobile station; and

,

a switching means for preventing the transmission of a subsequent downlink signal to the mobile station unless the base station is identified as a transmitting base station upon receiving the uplink signal indicating a preferred base station for transmitting the subsequent downlink signal, the preferred base station being determined responsive to a measure of a transmission property of the downlink signals at the mobile station.

30. The electronics device of claim 29, further comprising:

an identification means for identifying if the base station is the transmitting base station for transmitting a subsequent downlink signal to the mobile station.

31. Control circuitry, for use in a base station which transmits a downlink signal to a mobile station and receives an uplink signal from the mobile station through a wireless channel, the mobile station being capable of receiving downlink signals from each of a plurality of base stations, said control circuitry comprising:

a first controller to identify if the base station is a preferred base station upon the base station receiving an uplink signal indicating the preferred base station, among the plurality of base stations, for transmitting a subsequent downlink signal to the mobile station, the preferred base station being determined responsive to a measure of property of the downlink signals at the mobile station.

32. The control circuitry of claim 31, further comprising:

a second controller to enable the transmission of a subsequent downlink signal to the mobile station responsive to the base station being identified as the preferred base station.

33. Control circuitry for use in a base station which transmits a downlink signal to a mobile station and receives an uplink signal from the mobile station through a wireless channel, the mobile station being capable of receiving downlink signals from each of a plurality of other base stations, comprising:

a first controller to prevent the transmission of a subsequent downlink signal to the mobile station unless the base station is identified as a transmitting base station upon the base station receiving an uplink signal indicating a preferred base station, from among the plurality base stations, the preferred base station being determined responsive to a measure of a transmission property of the downlink signals from the mobile station.

34. The control circuitry of claim 33, further comprising:

a second controller to identify the transmitting base station for transmitting a subsequent downlink signal to the mobile station responsive to the uplink signal indicating the preferred base station.

35. A method for operating a cellular mobile communications network, comprising the steps of:

receiving a downlink signal from each of a plurality of base stations through a wireless channel;

measuring a transmission property of the downlink signals from the plurality of base stations;

deciding, in dependence upon the measured transmission property, a preferred base station, from among the plurality of base stations, for transmitting the downlink signal with a preferred transmission property; and

transmitting, to the plurality of base stations through the wireless channels, an uplink signal indicating the preferred base station to transmit a subsequent downlink signal from among the plurality of base stations.

36. The method of claim 35, further comprising the step of:

including, in the uplink signal, data indicating the preferred base station to transmit the subsequent downlink signal to the mobile station.

37. The method of claim 35, wherein the transmission property of the downlink signals from the plurality of base stations to the mobile station is represented by power levels of the received downlink signals.

38. A method for a cellular mobile communications network in which a mobile station is capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of the base stations through a wireless channel, comprising the steps of:

receiving the uplink signal indicating a preferred base station which is determined responsive to a measure of transmission property of the downlink signals at the mobile station; and

identifying, from among the plurality of base stations, the base station for transmitting a subsequent downlink signal to the mobile station responsive to the received uplink signal indicating a preferred base station.

39. The method of claim 38, further comprising the step of:

preventing the transmission of a subsequent downlink signal to the mobile station unless the base station was identified, from among the plurality of the base stations, as the base station for transmitting the subsequent downlink signal.

40. A method for a cellular mobile communications network in which a mobile station is capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of the base stations through a wireless channel, comprising the steps of:

receiving, from the mobile station, the uplink signal indicating a preferred base station which is determined responsive to a measure of a transmission property of the downlink signals; and

preventing from transmitting a subsequent downlink signal to the mobile station unless the base station is identified as the preferred base station, from among the plurality of the base stations.

41. The method of claim 40, further comprising the step of:

identifying the preferred base station, from among the plurality of base stations, for transmitting a subsequent downlink signal to the mobile station.

42. A cellular mobile communications network wherein

a mobile station is capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of the base stations through a wireless channel,

the mobile station produces a measure of a transmission property of the downlink signals from the plurality of base stations, and decides, in dependence upon the measure of the transmission property, a preferred base station, among the plurality of base stations transmitting the downlink signal with the preferred property, and,

each of the plurality of the base stations receives, from the mobile station, the uplink signal indicating the preferred base station, for transmitting a subsequent downlink signal to the mobile station.

43. The network of claim 42, wherein the mobile station transmits, to the plurality of base stations, the uplink signal including data which indicates the preferred base station for transmitting the subsequent downlink signal to the mobile station.

44. The network of claim 42, wherein the transmission property of the downlink signals from the plurality of base stations to the mobile station is represented by power levels of the received downlink signals.

45. A cellular mobile communications network wherein

a mobile station is capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel,

the mobile station produces a measure of a transmission property of the downlink signals from the plurality of base stations, and decides, in dependence upon the measure of the transmission property, a preferred base station, among the plurality of base stations, for transmitting the downlink signal with a preferred transmission property,

each of the plurality of the base stations receives, from the mobile station, the uplink signal indicating the preferred base station, among the plurality of base stations, for transmitting a subsequent downlink signal to the mobile station,

one or more of the base stations other than the preferred base station being prevented from transmitting a subsequent downlink signal to the mobile station.

46. The network of claim 45, wherein the mobile station transmits, to the plurality of base stations, the uplink signal including data which indicates the preferred base station for transmitting the subsequent downlink signal to the said mobile station.

47. The network of claim 45, wherein the transmission property of the downlink signals from the plurality of base stations to the mobile station is represented by power levels of the received downlink signals.

48. A cellular mobile communication network having a plurality of base stations, and a mobile station capable of receiving a downlink signal from each of said plurality of base stations and transmitting an uplink signal to the plurality of base stations, said cellular mobile communications network comprising:

a measuring unit for measuring a transmission characteristic of each downlink signal received at said mobile station;

a processing unit for comparing the measured transmission characteristic of each downlink signal and selecting a preferred downlink signal;

a selection unit for selecting a sub-set of said plurality of base stations to transmit a subsequent downlink signal responsive to said processing unit; and

a control unit for disabling the transmission of a subsequent downlink signal from non-selected base stations.

49. The cellular mobile communication network of claim 48, wherein

said mobile station includes said measuring unit and said processing unit.

50. The cellular mobile communication network of claim 48, further comprising:

a generation unit for generating a selection message for indicating the selected sub-set of said plurality of base stations to transmit a subsequent downlink signal base station.

51. The cellular mobile communication network of claim 50, wherein

said selection message is included in the uplink signal and includes data for indicating the selected sub-set of said plurality of base stations for transmitting a subsequent downlink signal.

52. The cellular mobile communication network of claim 50, wherein

said mobile station further includes said generation unit.

53. The cellular mobile communication network of claim 48, wherein

each of said base stations includes said control unit.

54. The cellular mobile communication network of claim 48, wherein

the transmission characteristic of the downlink signals from the plurality of base stations to the mobile station is represented by power levels of the received downlink signals.

55. A cellular mobile communications network, comprising:

a plurality of base stations each of which is capable of transmitting a downlink signal to a mobile station and receiving an uplink signal from the mobile station through a wireless channel, each base station including;

soft hand-off control unit for processing the uplink signal and identifying from the uplink signal a preferred base station for transmitting a subsequent downlink signal;

a mobile station for receiving the downlink signal from each of said plurality of base stations and transmitting the uplink signal to each of said plurality of base stations, said mobile station including;

a downlink signal processing unit for comparing the received downlink signals, selecting a preferred downlink signal and generating a message specifying the preferred base station transmitting the preferred downlink signal, said message to be transmitted by said mobile station; and

a base station controller, operatively connected to the plurality of base stations for delivering the downlink signals thereto for further transmission to the mobile station.

56. The cellular mobile communications network of claim 55, wherein

each of the plurality of base stations further comprises:

a switching unit for preventing the transmission of a subsequent downlink signal to the mobile station unless the base station is identified as the preferred base station.

57. The cellular mobile communications network of claim 55, wherein the downlink signal processing unit compares a transmission characteristic of the downlink signals.

58. The cellular mobile communications network of claim 57, wherein the transmission characteristic of the downlink signals from the plurality of base stations to the mobile station is represented by power levels of the received downlink signals.

59. A mobile station capable of receiving a downlink signal from each of a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel, comprising:

a downlink signal input unit for receiving the downlink signals from each of said base stations;

a comparison unit coupled to said downlink signal input unit and providing a comparison of a transmission characteristic of the downlink signals; and

a selection unit coupled to said comparison unit and responsive to said comparison unit, and providing a selection message identifying a preferred base station for transmitting a subsequent downlink signal to said mobile station, said selection message to be transmitted in the uplink signal.

60. The mobile station of claim 59, wherein

said downlink signal input unit receives the downlink signals from the plurality of base stations while each of the base stations are in a soft hand-off mode.

61. The mobile station of claim 59, wherein said selection message provided by said selection unit includes data for identifying the preferred base station from among a plurality of base stations in a soft hand-off mode.

62. The mobile station of claim 59, wherein said transmission characteristic is represented by power levels of the received downlink signals.

63. A base station of a cellular mobile communications network, the network having a plurality of base stations each capable of transmitting downlink signals to a mobile station, said mobile station capable of receiving the downlink signals from said plurality of base stations and transmitting an uplink signal to said plurality of base stations, said base station comprising:

an uplink signal input unit for receiving the uplink signal from said mobile stations;

a soft hand-off control unit coupled to receive the uplink signal from said uplink signal input unit, and determining from the uplink signal if the base station is a selected base station for transmitting a subsequent downlink signal;

wherein said uplink signal has data identifying a preferred base station for transmitting a subsequent downlink signal.

64. The base station of claim 63, further comprising:

a transmitter for transmitting the downlink signals to said mobile station; and

wherein said soft hand-off control unit further provides a disable signal to said transmitter to disable the transmission of the subsequent downlink signal when said base station is not said selected base station.

65. The base station of claim 63, wherein said preferred base station is determined responsive to a transmission characteristic of each of the downlink signals received at said mobile station while in a soft hand-off mode.

66. The base station of claim 65, wherein said transmission characteristic is represented by power levels of the received downlink signals.

67. A method of a soft hand-off operation in a mobile communications network where a plurality of base station are capable of transmitting downlink signals to and receiving uplink signals from a mobile station, comprising the steps of:

measuring transmission characteristic of each downlink signal received at said mobile station;

selecting a preferred downlink signal based on the measured transmission characteristic;

determining one or more preferred base stations of said plurality of base stations for transmitting a subsequent downlink signal responsive to said selecting step; and

disabling the transmission of the subsequent downlink signal from a base stations responsive to the determining step.

68. The method of claim 67, further comprising the step of:

generating a selection message for indicating the preferred base station; and

transmitting the selection message in the uplink signal.

69. The method of claim 68, wherein

said selection message includes a data for indicating the preferred base station for transmitting a subsequent downlink signal.

70. The base station of claim 67, wherein said transmission characteristic is represented by power levels of the received downlink signals.

71. A method for disabling the transmission of downlink signals in a mobile communications network wherein a base station controller provides downlink signals to a plurality of base stations, each capable of further transmitting the downlink signals to and receiving uplink signals from a mobile station, comprising the steps of:

comparing a transmission characteristic of each downlink signal received at said mobile station;

selecting a preferred downlink signal based on,the measured transmission characteristic;

identifying a preferred base station for transmitting a subsequent downlink signal based on the preferred downlink signal;

generating and transmitting a selection message in the uplink signal indicating the preferred base station;

identifying in each base station of said plurality of base stations whether said base station is the preferred base station responsive to the received uplink signal;

determining in each base station whether the base station should transmit the subsequent downlink signal responsive to the identifying step; and

disabling in each base station, the transmission of the subsequent downlink signal received from said base station controller when the base station determines it should not transmit.

72. The method of claim 71, wherein

said selection message includes data for indicating the preferred base station for transmitting a subsequent downlink signal.

73. The base station of claim 71, wherein said transmission characteristic is represented by power levels of the received downlink signals.

74. A method for a mobile station to select a preferred base station for transmitting a subsequent downlink signal from among a plurality of base stations, each base station capable of transmitting downlink signals to and receiving uplink signals from the mobile station while the mobile station is in a soft hand-off region, comprising the steps of:

receiving the downlink signals from each of the plurality of base stations;

comparing a transmission characteristic of the downlink signals;

selecting the preferred base station having a preferred transmission characteristic; and

transmitting the uplink signal indicating the preferred base station for transmitting a subsequent downlink signal to the mobile station.

75. The method of claim 74, wherein the uplink signal includes data for identifying the preferred base station from among the plurality of base stations in a soft hand-off mode.

76. The method of claim 74, wherein the transmission characteristic is represented by power levels of the received downlink signals.

77. A method for a base station to determine whether to transmit a downlink signal which is received from a base station controller, to a mobile station in a mobile communications network, wherein the base station controller provides downlink signals to a plurality of base stations, each capable of further transmitting the downlink signals to and receiving uplink signals from the mobile station, comprising the steps of:

receiving the uplink signal from the mobile station in a soft hand-off mode;

identifying from the uplink signal whether the base station is a preferred base station responsive to the received uplink signal;

determining whether to transmit a subsequent downlink signal responsive to the identifying step; and

disabling the transmission of the subsequent downlink signal received from said base station controller responsive to the determining step.

78. The method of claim 77, wherein

the uplink signal includes data for indicating the preferred base station for transmitting a subsequent downlink signal.

79. The method of claim 78, wherein the preferred base station is determined by a transmission characteristic of the downlink signal received at the mobile station.

80. The method of claim 79, wherein the transmission characteristic is represented by power levels of the received downlink signals.

81. A cellular mobile communications network in which a mobile station is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel, the mobile station being operable in one of operation modes selected from a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode, in which all of the plurality of base stations transmit the downlink signals to the mobile station.

82. The network of claim 81, wherein the mobile station is switchable between the first mode and second mode.

83. The network of claim 81, comprising a network controller, operatively connected to the plurality of base stations, for delivering the downlink signals to the plurality of base stations, and for selecting one of the operation modes from the first mode and the second mode.

84. The network of claim 81, comprising:

processing means for deciding the single base station transmitting the downlink signal with a preferred transmission property among the plurality of base stations in response to a measure of a transmission property of the downlink signals from the plurality of base stations to the mobile station when the mobile station operates in the first mode; and

,

identifying means for identifying, among the plurality of base stations, the single base station as decided by the processing means.

85. The network of claim 84, wherein the mobile station includes the processing means and the plurality of base stations include the identifying means.

86. The network of claim 85, wherein the processing means is operable to include, in the uplink signal, data indicating the single base station for transmitting the downlink signal to the mobile station.

87. The network of claim 85, wherein the transmission property of the downlink signals from the plurality of base stations to the mobile station is represented by power levels of the received downlink signals.

88. A cellular mobile communications network, comprising:

a mobile station capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel, and,

a network controller, operatively connected to the plurality of base stations, for delivering the downlink signals to the plurality of base stations, and for selecting one of operation modes including a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode, in which all of the plurality of base stations transmit the downlink signals to the mobile station.

89. The network of claim 88, wherein the network controller switches the operation mode between the first mode and the second mode.

90. The network of claim 88, wherein the mobile station operates in the operation mode selected by the network controller.

91. A mobile station which is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel,

and is operable in one of operation modes including a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode, in which all of the plurality of base stations transmit the downlink signals to the mobile station.

92. The mobile station of claim 91, wherein the operation mode is switchable between the first mode and the second mode.

93. The mobile station of claim 91, wherein the operation mode of the mobile station is selected in response to an operation mode selection made by a network controller, operatively connected to the plurality of base stations, delivering the downlink signals to the plurality of base stations.

94. A mobile station which is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel, comprising:

a processor for selecting an operation mode from amongst a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode, in which all of the plurality of base stations transmit the downlink signals to the mobile station.

95. The mobile station of claim 94, wherein the operation mode is switchable between the first mode and the second mode.

96. The mobile station of claim 94, wherein the processor decides the single base station transmitting the downlink signal with a preferred transmission property among the plurality of base stations in response to a measure of a transmission property of the downlink signals from the plurality of base stations to the mobile station in case of selecting the first mode.

97. The mobile station of claim 94, wherein the processor selects one of the operation modes in response to an operation mode selection made by a network controller, operatively connected to the plurality of base stations, delivering the downlink signals to the plurality of base stations.

98. Control circuitry for use in a mobile station which is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel, comprising:

a processor for selecting an operation mode from amongst a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode, in which all of the plurality of base stations transmit the downlink signals to the mobile station.

99. The mobile station of claim 98, wherein the operation mode is switchable between the first mode and the second mode.

100. The control circuitry of claim 98, wherein the processor decides the single base station transmitting the downlink signal with a preferred transmission property among the plurality of base stations in response to a measure of a transmission property of the downlink signals from the plurality of base stations to the mobile station in case of selecting the first mode.

101. The control circuitry of claim 98, wherein the processor selects one of the operation modes in response to a selection from the operation modes made by a network controller, operatively connected to the plurality of base stations, delivering the downlink signals to the plurality of base stations.

102. A network controller which manages a cellular mobile communications network in which a mobile station is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel, comprising:

means, operatively connected to the plurality of base stations, for delivering the downlink signals to the plurality of base stations; and

means for selecting an operation mode from amongst a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode in which all of the plurality of base stations transmit the downlink signals to the mobile station.

103. The network controller of claim 102, wherein the operation mode is switchable between the first mode and the second mode.

104. The network controller of claim 102, further comprising:

means for informing the mobile station of the selected operation mode.

105. A network controller which manages a cellular mobile communications network in which a mobile station is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel;

comprising;

a transmitter, operatively connected to the plurality of base stations, for delivering the downlink signals to the plurality of base stations; and

a processor for selecting an operation mode from amongst a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode in which all of the plurality of base stations transmit the downlink signals to the mobile station.

106. The network controller of claim 105, wherein the processor switches one of the operation modes between the first mode and the second mode.

107. The network controller of claim 105, wherein the processor informs the mobile station of the selected operation mode.

108. Control circuitry for use in a network controller which manages a cellular mobile communications network in which a mobile station is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel, comprising:

a processor for selecting one of operation modes including a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode in which all of the plurality of base stations transmit the downlink signals to the mobile station.

109. The control circuitry of claim 108, wherein the processor switches the operation mode between the first mode and second mode.

110. The control circuitry of claim 108, wherein the processor produces a signal for informing the mobile station of the selected operation mode.

111. A method for a cellular mobile communications network in which a mobile station is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel;

comprising;

providing operation modes including a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode, in which all of the plurality of base stations transmit the downlink signals to the mobile station; and

selecting one of the operation modes from the first mode and second mode.

112. The method of claim 111, further comprising:

switching the operation mode between the first mode and second mode.

113. A method for a mobile station which is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel, comprising:

receiving operation mode information specifying an operation mode selected from amongst a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode, in which all of the plurality of base stations transmit the downlink signals to the mobile station; and

controlling the operation mode in accordance with the specified one of the operation modes.

114. A method for a network controller which manages a cellular mobile communications network in which a mobile station is capable of receiving downlink signals from a plurality of base stations and transmitting an uplink signal to the plurality of base stations through a wireless channel;

comprising;

selecting an operation mode from amongst a first mode, in which a single base station of the plurality of base stations transmits the downlink signal to the mobile station, and a second mode in which all of the plurality of base stations transmit the downlink signals to the mobile station; and

,

informing the mobile station of the selected operation mode.