Abstract:
To provide a base station apparatus that can automatically update the parameters required for radio communication. A pair of identifier for identifying the self station and radio communication parameter is notified to another base station existing in the neighborhood of the self station, and the path loss value between another base station and a mobile station and the pair of identifier and radio communication parameter for another base station is acquired. The pair of identifier and radio communication parameter reported by the self station is set and updated, based on this acquired information. Since it is updated in consideration of the path loss value reported from the mobile station, the parameter can be updated at higher precision.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a base station apparatus, a mobile station apparatus, and a method for updating the radio communication parameters, and particularly to a base station apparatus of multiple access method in which a plurality of users make the communications at the same time by sharing a radio channel, a mobile station apparatus, and a method for updating the temporary radio communication parameters.  
         [0003]     2. Description of the Related Art  
         [0004]     As the multiple access methods in which a plurality of users make the communications by sharing a radio channel, a code division multiple access (CDMA), a time division multiple access (TDMA) and a frequency division multiple access (FDMA) are well known.  
         [0005]     For example, in a communication system of code division multiple access method in which the same frequency band is shared among a plurality of communication waves, individual communication waves are distinguished by the spreading codes of random code series. As the spreading code is better in the detection characteristic (auto-correlation characteristic) and the identification characteristic (cross-correlation characteristic) between different spreading codes, the system efficiency is improved. Therefore, all the random combinations of codes determined by the series length are not employed, but the code series to attain the required characteristics are selectively employed. Accordingly, when the high system efficiency is required, the spreading code is limited and the assignable number of spreading codes is below the total number of simultaneous communication waves supposed for the system.  
         [0006]     Particularly in the satellite downlink of a W-CDMA (Wideband CDMA) cellular system, the spreading code used is demanded to have the code orthogonality capable of reducing mutual interference between different spreading codes, in addition to the high detection characteristic and identification characteristic, to implement high quality communications even at low transmission power. Therefore, the assignable number of spreading codes is smaller than in the satellite uplink. This small number of spreading codes is repeatedly employed for effective use, but a different code for each cell is employed and superimposed to prevent radio interference between cells.  
         [0007]     In the W-CDMA cellular system, the spreading code for actually spreading the user data in the broadband is called a channelization code, and the code for preventing radio interference between cells superimposed for each cell is called a scrambling code.  
         [0008]     Each base station apparatus (hereinafter simply referred to as a base station) forming each cell of the W-CDMA cellular system reports the down scrambling code employed by its peripheral base station on the control channel so that a mobile station apparatus (hereinafter simply referred to as a mobile station) may detect the cell at high speed, and the mobile station makes the reception of the satellite downlink for the scrambling code notified on the control channel. Accordingly, when the down scrambling code is assigned to a certain base station, in order to enable the mobile station to make the reception on the satellite downlink of the base station, and then make the reception on another satellite downlink around the satellite downlink, it is required that the down scrambling code of the peripheral base station located around the base station is set on the control channel of the base station and reported to the mobile station belonging to the cell formed by the base station.  
         [0009]     A technique in which the mobile station acquires the information of the base station and reports it to the base station to which the self station is connected, and the bases station update the information was described in JP2001-54158A.  
       SUMMARY OF THE INVENTION  
       [0010]     In the case where the update method of base station information as described in the JP2001-54158A is adopted, the radio communication parameter such as scrambling code employed by the base station can not be automatically set up at high precision, because the path loss between the base station and the mobile station is not taken into consideration.  
         [0011]     This invention has been achieved to solve the above-mentioned problem associated with the prior art, and it is an object of the invention to provide a base station apparatus, a mobile station apparatus and a radio communication parameter update method in which the radio communication parameter employed by the peripheral base station can be automatically set up as the parameter reported by the self base station at high precision.  
         [0012]     According to claim  1  of the invention, there is provided a base station apparatus comprising radio communication parameter notification means (corresponding to a base station identifier and scrambling code notification part  108  and a transmitting part  102  in  FIG. 3  as will be described later) for notifying a pair of identifier for identifying a self station and radio communication parameter to another base station in the neighborhood of the self station, information acquisition means (corresponding to a receiving part  104  in  FIG. 3  as will be described later) for acquiring at least one of a path loss value between another base station and a mobile station, a reception level and an arrival time difference between control channels, and the pair of identifier and radio communication parameter for another base station, and radio communication report parameter update means (corresponding to a base station identifier and scrambling code setting part  106  and a base station identifier and scrambling code report update part  110  in  FIG. 3  as will be described later) for setting and updating the pair of identifier and radio communication parameter reported by the self station, based on the information acquired by the information acquisition means. This claim  1  is concerned with a newly established base station  1004  as will be described later. With this constitution, the parameter can be updated, based on the path loss measured value and the radio communication parameter for the peripheral base station, and therefore updated at higher precision.  
         [0013]     According to claim  2  of the invention, there is provided the base station apparatus according to claim  1 , wherein the radio communication report parameter update means sets the pair of identifier and radio communication parameter for the base station having a smaller preset path loss value as the preferentially reported pair, in which if the path loss value is equal, the pair having a greater number of appearances is set as the preferentially reported pair. The claim  2  is concerned with a newly established base station  1004  as will be described later. With this constitution, the parameter can be updated at high precision, based on the path loss measured value and the radio communication parameter, and appropriately updated based on the number of appearances, even if the path, loss value is equal.  
         [0014]     According to claim  3  of the invention, there is provided the base station apparatus according to claim  1 , wherein the radio communication report parameter update means sets the pair of identifier and radio communication parameter for the base station having a greater preset number of appearances as the preferentially reported pair, in which if the number of appearances is equal, the pair having a smaller preset path loss value is set as the preferentially reported pair. The claim  3  is concerned with a newly established base station  1004  as will be described later. With this constitution, the parameter can be updated at high precision, based on the path loss measured value and the radio communication parameter, and appropriately updated based on the path loss value, even if the number of appearances is equal.  
         [0015]     According to claim  4  of the invention, there is provided a base station apparatus comprising information acquisition means (corresponding to a receiving part  104  in  FIG. 3  as will be described later) for acquiring a pair of identifier for identifying a base station and radio communication parameter from a newly established base station that is newly provided, and radio communication parameter report means (corresponding to a base station identifier and scrambling code setting part  106  and a transmitting part  102  in  FIG. 3  as will be described later) for reporting the information acquired by the information acquisition means together with the pair of identifier for identifying the self station and radio communication parameter to a mobile station belonging to a cell formed by the self station. The claim  4  is concerned with the existent base stations  1001  and  1002  as will be described later. With this constitution, by acquiring the path loss value from the mobile station, the parameter can be updated at high precision, based on the path loss value.  
         [0016]     According to claim  5  of the invention, there is provided the base station apparatus according to claim  4 , further comprising path loss update means (corresponding to a base station identifier and scrambling code setting part  106  and a base station identifier and scrambling code report update part  110  in  FIG. 3  as will be described later) for updating the path loss value in the pair of identifier and radio communication parameter based on a measurement report, only if the measurement report including the path loss values in the pairs of identifier and radio communication parameter for the newly established base station and the self station is acquired from the mobile station, and path loss notification means (corresponding to a base station identifier and scrambling code setting part  106  and a transmitting part  102  in  FIG. 3  as will be described later) for transmitting the path loss value in the pair of identifier and radio communication parameter reported by the self station to the newly established base station, if the measurement report is acquired. The claim  5  is concerned with the existent base stations  1001  and  1002  as will be described later. With this constitution, the newly established base station acquiring the path loss value can update the parameter at higher precision, based on the path loss value.  
         [0017]     According to claim  6  of the invention, there is provided the base station apparatus according to claim  4 , further comprising radio communication report parameter notification request means (corresponding to a base station identifier and scrambling code notification part  108  and a transmitting part  102  in  FIG. 3  as will be described later) for making a request to the base station to notify all the pairs of identifier and radio communication parameter reported by the base station to the newly established base station, if the path loss values in the pairs of identifier and radio communication parameter for the newly established base station and the base station other than the self station are acquired from the mobile station. The claim  6  is concerned with the existent base stations  1001  and  1002  as will be described later. With this constitution, the pair of identifier and radio communication parameter can be set up more appropriately by taking into consideration the report information of the base station located in the distance from the newly established base station.  
         [0018]     According to claim  7  of the invention, there is provided the base station apparatus according to claim  5 , wherein the path loss update means makes any one of an average value of measurements of the path loss value and a minimum value of the measurements an update value of the path loss value, if the measurement reports are acquired from a plurality of mobile stations. The claim  7  is concerned with the existent base stations  1001  and  1002  as will be described later. With this constitution, the parameter can be updated at higher precision.  
         [0019]     According to claim  8  of the invention, there is provided the base station apparatus according to claim  5 , wherein the path loss notification means transmits the path loss value in the pair of identifier and radio communication parameter reported by the self station to the newly established base station, if the measurement reports are acquired from a predetermined number of mobile stations. The claim  8  is concerned with the existent base stations  1001  and  1002  as will be described later. With this constitution, the parameter can be updated at higher precision.  
         [0020]     According to claim  9  of the invention, there is provided a base station apparatus comprising radio communication report parameter notification response means (corresponding to a base station identifier and scrambling code setting part  106  and a transmitting part  102  in  FIG. 3  as will be described later) for notifying all the pairs of identifier and radio communication parameter reported by the self station to the newly established station, if another base station makes a request for notifying all those pairs to the newly established base station that is newly provided. The claim  9  is concerned with an existent base station  1003  as will be described later. With this constitution, the pair of identifier and radio communication parameter can be set up more appropriately by taking into consideration the report information of the base station located in the distance from the newly established base station.  
         [0021]     According to claim  10  of the invention, there is provided a mobile station apparatus comprising path loss measurement means (corresponding to a scrambling code/base station identifier/path loss measurement part  306  in  FIG. 6  as will be described later) for measuring the path loss value that is a power difference between the transmission power of abase station to which the self station can be connected and the reception power of the self station, and notification means (corresponding to a scrambling code/base station identifier/path loss measurement part  306  and a transmitting part  302  in  FIG. 6  as will be described later) for notifying the path loss value measured by the path loss measurement means to the base station. With this constitution, the path loss value can be acquired on the base station side, and the pair of identifier and radio communication parameter can be set up more appropriately on the base station side.  
         [0022]     A radio communication parameter update method according to claim  11  of the invention is provided in a radio communication system wherein a base station and a mobile station belonging to a cell formed by the base station communicate, the base station automatically setting up a parameter required for radio communication and incorporation into a radio access network when newly established, the radio communication parameter update method allowing the newly established base station to report a pair of identifier and radio communication parameter for an existent base station that exists to form a cell adjacent to the cell formed by the newly established base station that is newly provided to the mobile station belonging to the cell formed by the newly established base station, comprising:  
         [0023]     a step (corresponding to step S 1102  in  FIG. 5  as will be described later) at which the newly established base station sets up the pair of base station identifier and radio communication parameter for the self station;  
         [0024]     a step (corresponding to steps S 1104 , S 1108  and S 1112  in  FIG. 5  as will be described later) at which the newly established base station notifies the pair of base station identifier and radio communication parameter for the self station to the first existent base station in the neighborhood;  
         [0025]     a step (corresponding to steps S 1114  and S 1116  in  FIG. 5  as will be described later) at which the first existent base station reports the pair of base station identifier and radio communication parameter for the newly established base station, in addition to the pair of base station identifier and radio communication parameter reported to the mobile station belonging to the cell formed by the first existent base station, to the mobile station, based on a notification of the pair of base station identifier and radio communication parameter from the newly established base station;  
         [0026]     a step (corresponding to steps S 1118  and S 1122  in  FIG. 5  as will be described later) at which the first existent base station receives a measurement report including the path loss value from the mobile station, the path loss value being a power difference between the transmission power of the base station and the reception power of the mobile station in the pair of identifier and radio communication parameter for the base station to which the mobile station can be connected among all the pairs of identifier and radio communication parameter reported from the first existent base station;  
         [0027]     a step (corresponding to steps S 1120  and S 1124  in  FIG. 5  as will be described later) at which the first existent base station updates the hold value of the path loss value in the pair of identifier and radio communication parameter based on a measurement report of the path loss values, only if the measurement report including the path loss values in the pairs of identifier and radio communication parameter for both the newly established base station and the first existent base station is received from the mobile station;  
         [0028]     a step (corresponding to steps S 1128  and S 1130  in  FIG. 5  as will be described later) at which the second existent base station notifies the hold value of the path loss value to the newly established base station, the path loss value being in each of the pairs of identifier and radio communication parameter reported in the second existent base station receiving the measurement report including the path loss values in the pairs of identifier and radio communication parameter for both the self station and the newly established base station from the mobile station among the first base stations;  
         [0029]     a step (corresponding to step S 1126  in  FIG. 5  as will be described later) at which the second existent base station makes a request to the third existent base station to notify all the pairs of identifier and radio communication parameter reported by the third existent base station to the newly established base station, if a measurement report of the path loss values in the pairs of identifier and radio communication parameter for the third existent base station in addition to the newly established base station and the second existent base station is notified from the mobile station to the second existent base station;  
         [0030]     a step (corresponding to step S 1132  in  FIG. 5  as will be described later) at which the third existent base station notifies all the pairs of identifier and radio communication parameter reported by the third existent base station to the newly established base station based on the request; and  
         [0031]     a step (corresponding to step S 1134  in  FIG. 5  as will be described later) at which the newly established base station updates the pair of identifier and radio communication parameter reported by the newly established base station, based on all the identifiers notified from the second existent base station, the path loss hold value in the radio communication parameter, all the identifiers notified from the third existent base station and the radio communication parameter. With this constitution, the parameter can be updated at higher precision. Whether or not the base stations are located in the neighborhood is determined based on the path length between the base stations.  
         [0032]     As described above, the invention has the effect that the pair of base station identifier and radio communication parameter, which the base station should report to the mobile station belonging to the cell formed by the base station, can be automatically set up at higher precision, based on the path loss measured value and the reporting radio communication parameter for the peripheral base station. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0033]      FIGS. 1A and 1B  are explanatory views showing the configuration of a radio access network in newly establishing a base station according to an embodiment of the invention;  
         [0034]      FIGS. 2A and 2B  are views showing a configuration example in which a server for managing the identifier of each base station is added in the radio access network of  FIGS. 1A and 1B ;  
         [0035]      FIG. 3  is a block diagram showing the configuration of the base station according to the embodiment of the invention;  
         [0036]      FIG. 4  is a block diagram showing the configuration of a control router according to the embodiment of the invention;  
         [0037]      FIG. 5  is a sequence diagram showing a process for updating the base station identifier and the scrambling code reported by the newly established base station;  
         [0038]      FIG. 6  is a block diagram showing the configuration of a mobile station according to the embodiment of the invention;  
         [0039]      FIG. 7  is a view showing the information reported from the mobile station to the base station;  
         [0040]      FIG. 8  is a view showing how the base station identifier, scrambling code and path loss hold value reported by the existent base station are notified to the newly established base station; and  
         [0041]      FIG. 9  is a view showing a process for setting the base station identifier and the scrambling code reported by the newly established base station based on the base station identifier, the scrambling code and the path loss reported by the peripheral base station. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0042]     The preferred embodiments of the present invention will be described below with reference to the drawings. In the following explanation, the parts having the same functions are designated by the same reference numerals or signs throughout the drawings, and the repeated explanation is omitted.  
         [0043]     (Configuration Example of Radio Access Network)  
         [0044]     Referring to  FIGS. 1A and 1B , a configuration example of a radio access network according to this embodiment will be described below.  FIG. 1A  shows a state before a base station is newly established, and  FIG. 1B  shows a state after the base station is newly established.  
         [0045]     In the radio access network of this example, a CDMA (Code Division Multiple Access) cellular system is adopted in which a mobile station belonging to a cell and each base station forming the cell make the communication by sharing the same frequency band in a plurality of adjacent cells. This network comprises a base station  100   i  (i is the natural number) and a control router  200   k  (k is the natural number). In this example, the base stations  1001  to  1003  and the control routers  2001  and  2002  are provided in the network, as shown in  FIGS. 1A and 1B . And the down scrambling code different for each base station forming the cell, namely, the spreading code used for transmission through the satellite downlink is set up. Also, for each base station forming the cell, a pair of base station identifier and scrambling code for the peripheral base station forming the cell located around the cell is set up, and reported to the mobile station belonging to the cell formed by the base station.  
         [0046]     Referring to  FIG. 1A , in this example, in the base station  1001 , the base stations to report the scrambling code and the base station identifier are the base station  1002  and the base station  1001  (i.e., self station). In the base station  1002 , the base stations to report the scrambling code and the base station identifier are the base station  1001  and the base station  1002  (i.e., self station). In the base station  1003 , the base station to report the scrambling code and the base station identifier is the base station  1003  (i.e., self station alone).  
         [0047]     The radio access network of this example may adopt a FDD (Frequency Division Duplex) or TDD (Time Division Duplex) method of the CDMA. Also, the radio access network according to this embodiment may be a TDMA (Time Division Multiple Access) cellular system or a FDMA (Frequency Division Multiple Access) cellular system, besides the CDMA (Code Division Multiple Access) cellular system.  
         [0048]     Each of the base stations  1001 ,  1002  and  1003  is accommodated in any of the control routers  2001  and  2002 . In this example, at first, the base stations  1001  and  1002  are accommodated in the control router  2001  and the base station  1003  is accommodated in the control router  2002 , as shown in  FIG. 1A . Thereafter, the base station  1004  is newly established and accommodated in the control router  2001 , as shown in  FIG. 1B . As a result, in the base station  1001 , the base stations to report the scrambling code and the base station identifier are the base stations  1002 , the base station  1004  and base station  1001  (i.e., self station) in this example, as shown in  FIG. 1B . In the base station  1002 , the base stations to report the scrambling code and the base station identifier are the base station  1001 , the base stations  1004  and the base station  1002  (i.e., self station). In the base station  1003 , the base station to report the scrambling code and the base station identifier is the base station  1003  (i.e., self station alone). In the base station  1004 , the base stations to report the scrambling code and the base station identifier are the base stations  1001 , the base station  1002  and the base station  1004  (i.e., self station).  
         [0049]     The base stations  1001  to  1004  are interconnected through the control routers  200  in combinations of base stations. Also, the base station  100  holds a pair of base station identifier and scrambling code for the peripheral base station to which the self base station makes a report, in which its contents can be inquired from another base station.  
         [0050]     The identifier of the base station  100   i  required to hold uniqueness in the entire system may be managed by providing a server, and inquired from the control router. For example, a server  400  for managing the identifier of each base station may be provided, and each base station  100   i  or the control router  200   k  may make access to the server  400  via the Internet  500  to make the inquiry, as shown in  FIGS. 2A and 2B .  
         [0051]     In  FIGS. 2A and 2B , the server  400  is logically connected to the control router  200   k  and the base station  100   i , but no hierarchical relationship between the control router and the base station may be employed in the node configuration. That is, when the base station identifier is transmitted or received between the server  400  and the base station  100   i , the data transfer may occur without interposition of the control router  200   k . Conversely, the base station identifier may be transmitted or received via the control router  200 k.  
         [0052]     The number of servers provided is not specifically limited. One server is provided in the entire system, as shown in  FIGS. 2A and 2B , but a plurality of servers may be provided to distribute the load, for example.  
         [0053]     While in  FIGS. 1A, 1B ,  2 A and  2 B, the base stations  1001 ,  1002  and  1004  are under the control router  2001 , and the base station  1003  is under the control router  2002 , they are not limited to such affiliated relation but may be in any other affiliated relation.  
         [0054]     (Configuration Example of Base Station)  
         [0055]     Referring to  FIG. 3 , a configuration example of the base station  100   i  in  FIGS. 1A and 1B  will be described below. In  FIG. 3 , the base station  100   i  of this example comprises a transmitting part  102  for transmitting various signals to the outside, a receiving part  104  for receiving various signals from the outside, a base station identifier and scrambling code setting part  106  connected to the transmitting part  102  and the receiving part  104 , a base station identifier and scrambling code notification part  108  connected to the transmitting part  102  and the scrambling code setting part  106 , and a base station identifier and scrambling code report update part  110  connected to the transmitting part  102 , the receiving part  104 , the scrambling code setting part  106  and the base station identifier and scrambling code notification part  108 .  
         [0056]     In this configuration, the setting contents of the identifier and the down scrambling code for the base station  100   i  are set up by the base station identifier and scrambling code setting part  106 . The transmitting part  102  starts to transmit the base station identifier on the control channel spread by the down scrambling code.  
         [0057]     The base station identifier and scrambling code notification part  108  transmits the base station identifier and the down scrambling code set in the self base station to another base station  100  via the transmitting part  102 . Also, the receiving part  104  receives all the pairs of base station identifier and down scrambling code reported by the peripheral base station forming the cell located around the cell formed by the self base station and the path loss hold value in the pair of base station identifier and down scrambling code stored in the peripheral base station, and the base station identifier and scrambling code report update part  110  updates the pair of base station identifier and radio communication parameter reported to the mobile station belonging to the cell formed by the self base station.  
         [0058]     (Configuration Example of Control Router)  
         [0059]     Referring to  FIG. 4 , a configuration example of the control router  200   k  of  FIGS. 1A and 1B  will be described below. In  FIG. 4 , the control router  200   k  of this example comprises a transmitting part  202  for transmitting various signals to the outside, a receiving part  204  for receiving various signals from the outside, and a base station identifier assignment part  206  connected to the transmitting part  202  and the receiving part  204 .  
         [0060]     In this configuration, the identifier of the newly established base station is transmitted from the server and received by the receiving part  204 . The base station identifier assignment part  206  transmits the base station identifier to the newly established base station via the transmitting part  202 .  
         [0061]     (Communication of Signals Between Base Stations)  
         [0062]     Referring to  FIG. 5 , the operation of automatically setting the pair of base station identifier and down scrambling code reported by the newly established base station after starting to transmit the identifier of the newly established base station on the control channel spread by the down scrambling code set by the newly established base station will be described below. In  FIG. 5 , communication of signals between the newly established base station  1004  and the existent base stations  1001  to  1003  is shown.  
         [0063]     In  FIG. 5 , the newly established base station  1004  starts to transmit the identifier of the self station on a common control channel spread by the down scrambling code set in the self station (step S 1102 ). Thereafter, the newly established base station  1004  makes a request to the existent base stations  1001  to  1003  to add the pair of base station identifier and down scrambling code for the newly established base station  1004  to the pair of base station identifier and down scrambling code reported by the existent base stations  1001  to  1003  (steps S 1104 , S 1108  and S 1112 ).  
         [0064]     The existent base stations  1001  and  1002 , which have been able to receive the request signal for adding the base station identifier and the scrambling code from the newly established base station  1004  under the condition of at least one of within a certain required time and within a certain number of router relays, adds the pair of base station identifier and down scrambling code for the newly established base station  1004  to the pair of base station identifier and down scrambling code reported by the self base station  1004  (steps S 1106  and S 1110 ). On the other hand, the existent base station  1003  that has not been able to receive the request under the above condition does not add the pair of base station identifier and down scrambling code for the newly established base station  1004  (step S 1112 ).  
         [0065]     The existent base stations  1001  and  1002  that have added the pair of base station identifier and down scrambling code for the newly established base station  1004  to the pair of base station identifier and down scrambling code reported returns a response to the request for adding the base station identifier and the scrambling code from the newly established base station  1004  (steps S 1114  and S 1116 ).  
         [0066]     The mobile stations (Mobile Station: MS)  3001  and  3002  that are receivable on the common control channel for the newly established base station  1004  newly identify the down scrambling code and the base station identifier for the newly established base station  1004 , and notify a measurement report of the path loss for the pairs of base station identifier and down scrambling code for the existent base stations  1001  and  1002  and the newly established base station  1004 , to which the mobile station belongs, to the affiliated existent base stations  1001  and  1002 , and the existent base station  1001  and  1002  receive this report (steps S 1118  and S 1122 ). The existent base stations  1001  and  1002  update the path loss hold value held in the existent base stations  1001  and  1002 , based on the measurement report of the path loss (steps S 1120  and S 1124 ).  
         [0067]     If the measurement report of the mobile station (Mobile Station: MS)  3002  includes the path loss for the pair of base station identifier and down scrambling code for the existent base station  1003 , in addition to the existent base station  1002  and the newly established base station  1004  to which the mobile station belongs, the existent base station  1002  receiving this measurement report makes a request to the existent base station  1003  to notify all the pairs of base station identifier and down scrambling code reported by the existent base station  1003  to the newly established base station  1004  (step S 1126 ).  
         [0068]     Herein, the existent base station makes a request to the newly established base station to notify the measurement report to the other existent base station, if the measurement report includes the path loss for the pair of base station identifier and down scrambling code for the other existent base station, in addition to the self station and the newly established base station. However, if only the path losses for the self station and the newly established base station are included (i.e., the path loss for the other existent base station is not included), no notification request is made. In this example, the existent base station  1002  has received the measurement report including the path loss for the pair of base station identifier and down scrambling code for the existent base station  1003 , in addition to the self station and the newly established base station. On the contrary, the existent base station  1001  has received the measurement report including only the path losses for the self station and the newly established base station, whereby the existent base station  1002  alone issues a notification request to the existent base station  1003 .  
         [0069]     The existent base stations  1001  and  1002  receiving the measurement report of the path loss from the mobile stations MS 3001  and  3002  transfer all the pairs of base station identifier and down scrambling code reported by the self base station and the path loss hold values in those pairs to the newly established base station  1004  (steps S 1128  and S 1130 ).  
         [0070]     The existent base station  1003  receiving the request from the existent base station  1002  to notify the pair of base station identifier and down scrambling code reported by the existent base station  1003  to the newly established base station  1004  transfers the pair of base station identifier and down scrambling code reported by the self base station to the newly established base station  1004  (step S 1132 ).  
         [0071]     The scrambling code setting part  106  of the newly established base station  1004  sets the pair of base station identifier and down scrambling code reported by the newly established base station  1004  by referring to all the transferred pairs of base station identifier and down scrambling code reported by the existent base stations  1001  and  1002  with the path loss hold values corresponding to those pairs and all the pairs of base station identifier and down scrambling code reported by the existent base station  1003  (step S 1134 ).  
         [0072]     Also, the newly established base station  1004  makes a request to the existent base station  1003  to add the pair of base station identifier and down scrambling code for the newly established base station  1004 , the existent base station  1003 , among the existent base stations  1001  to  1003  corresponding to all the pairs of base station identifier and down scrambling code reported by the self base station, having not yet added the pair of base station identifier and scrambling code for the newly established base station  1004  as the pair of base station identifier and scrambling code to report (step S 1136 ). The existent base station  1003  receiving this request adds the pair of base station identifier and down scrambling code for the newly established base station  1004  to the pair of base station identifier and down scrambling code reported by the self base station (step S 1138 ). And the existent base station  1003  makes a notification of completion of adding the pair of base station identifier and down scrambling code fore the newly established base station  1004  to the newly established base station  1004  (step S 1140 ).  
         [0073]     In the above manner, when the reporting radio communication parameter for the newly established station is setup, the parameter is updated based on the path loss measured value of the peripheral base station notified from the mobile station and the reporting radio communication parameter of the peripheral base station, whereby the parameter can be updated at higher precision.  
         [0074]     (Configuration Example of Mobile Station)  
         [0075]     Referring to  FIG. 6 , a configuration example of the mobile station  300   m  (m is the natural number) will be described below. In  FIG. 6 , the mobile station  300   m  comprises a transmitting part  302  for transmitting various signals to the outside, a receiving part  304  for receiving various signals from the outside, and a scrambling code/base station identifier/path loss measurement part  306  connected to the transmitting part  302  and the receiving part  304 . This mobile station is the mobile terminal equipment such as a cellular phone, a PDA (Personal Digital Assistant) or a notebook type computer.  
         [0076]     The scrambling code/base station identifier/path loss measurement part  306  reports the identifier of the base station  100   i  and the down scrambling code of the base station  100   i  to the existent base station  100   i  via the transmitting part  302 . Also, the scrambling code/base station identifier/path loss measurement part  306  measures a difference (i.e., path loss) between the transmission power of the base stations  100   i  and the reception power of the mobile station and reports it to the existent base station  100   i  via the transmitting part  302 .  
         [0077]     The scrambling code/base station identifier/path loss measurement part  306  of the mobile station  300   m  reports the identifier, the down scrambling code and the path loss for the base station that could be measured at the same time, other than the base stations  1001  to  1003  and the newly established base station  1004 , to which the measurement report is addressed. However, for the convenience&#39;s sake of explanation, it is supposed that the path loss with only the base stations  1001  to  1003  and the newly established base station  1004  to which the measurement report is addressed can be measured.  
         [0078]     (Example of Measurement Report)  
         [0079]     Referring to  FIG. 7 , the information (measurement report) reported from the mobile station  300  to the base station  100  will be described below.  
         [0080]     As shown in  FIG. 7 , the scrambling code/base station identifier/path loss measurement part  306  of the mobile station MS 3001  transmits the path loss “PL#1” in the pair of down scrambling code “Sc#1 and base station identifier “BSid#1” for the base station  1001  at the destination and the path loss “PL#4” in the pair of down scrambling code “Sc#4 and base station identifier “BSid#4” for the newly established base station  1004 , as the measurement report, to the existent base station  1001 .  
         [0081]     Also, the scrambling code/base station identifier/path loss measurement part  306  of the mobile station MS 3002  transmits the path loss “PL#2” in the pair of down scrambling code “Sc#2 and base station identifier “BSid#2” for the base station  1002  at the destination and the path loss “PL#4” in the pair of down scrambling code “Sc#4 and base station identifier “BSid#4” for the newly established base station  1004 , as the measurement report, to the existent base station  1002 . Further, in the mobile station MS 3002 , the path loss “PL#3” in the pair of down scrambling code “Sc#3 and base station identifier “BSid#3” for the base station  1003  connectable in addition to the base station  1002  and the newly established base station  1004  is transmitted as the measurement report.  
         [0082]     The scrambling code/base station identifier/path loss measurement part  306  of the mobile station MS 300   m  may report the reception level and the arrival time difference of the control channel, other than the identifier, the down scrambling code and the path loss for the base station.  
         [0083]     (Method for Transmitting Information to Newly Established Base Station)  
         [0084]     Referring to  FIG. 8 , a method for allowing the base stations  1001  to  1003  to transmit all the pairs of base station identifier and down scrambling code reported by the existent base stations  1001  and  1002  with the path loss hold values in those pairs and all the pairs of base station identifier and down scrambling code reported by the base station  1003  to the newly established base station  1004  will be described below.  
         [0085]     In  FIG. 8 , the existent base stations  1001  and  1002  update the path loss hold value in each pair of base station identifier and down scrambling code, only if the path loss in the pair of base station identifier and down scrambling code in the newly established base station  1004 , in addition to the existent base stations  1001  and  1002  being connected, is included in the reception report of the path loss received from the mobile station  300   m  belonging to the cell formed by the self base station. For example, the existent base station  1001  updates the path loss hold value for the measurement report acquired from the mobile station  3001  in  FIG. 8  (S 1   a ). On the other hand, the measured report (× sign in  FIG. 8 ) that could not be acquired is not subject to updating the path loss hold value (S 1   b ). The existent base station  1002  likewise updates the path loss hold value for the measurement report acquired from the mobile station  3002  in  FIG. 8  (S 2   a ), and the measurement report (× sign in  FIG. 8 ) that could not be acquired is not subject to updating the path loss hold value (S 2   b ). The path loss hold value may be updated based on the average value or minimum value of the path loss measured values received up to the present time in each pair of base station identifier and down scrambling code.  
         [0086]     If the existent base stations  1001  and  1002  receive a certain number of path loss measurement reports subject to updating the path loss hold value, an update process for the path loss hold value is ended. And the existent base stations  1001  and  1002  notify all the pairs of base station identifier and down scrambling code reported by the existent base stations  1001  and  1002  and the path loss hold values in those pairs to the newly established base station  1004 . This notification is transmitted via the control router  2001  to the newly established base station  1004  (S 3 ).  
         [0087]     Also, if the existent base stations  1001  and  1002  store the path loss hold value in the pair of base station identifier and down scrambling code other than the self base station and the newly established base station  1004 , they make a request to the existent base station  1003  corresponding to the pair of base station identifier and down scrambling code to transmit all the pairs of base station identifier and down scrambling code reported by the existent base stations  1003  to the newly established base station  1004  (S 4 ). Based on this request, the existent base station  1003  transmits all the pairs of base station identifier and down scrambling code reported by the self base station to the newly established base station  1004  (S 5 ).  
         [0088]     In the newly established base station  1004 , the base station identifier and scrambling code report update part  110  sets the pair of base station identifier and down scrambling code reported by the newly established base station  1004  to the self station, based on all the notified pairs of base station identifier and down scrambling code reported by the base stations  1001  and  1002  with the path loss hold values in those pairs, and all the pairs of base station identifier and down scrambling code reported by the base station  1003 .  
         [0089]     (Example of Pair of Base Station Identifier and Down Scrambling Code)  
         [0090]      FIG. 9  is a view showing the examples of the pair of base station identifier and down scrambling code reported by the newly established base station  1004 , which are generated in the base station identifier and scrambling code report update part  110 .  
         [0091]     Referring to  FIG. 9 , in the existent base station  1001 , the pair of down scrambling code “Sc#2” and base station identifier “BSid#2”, the pair of “Sc#3” and “BSid#3”, the pair of “Sc#a” and “BSid#a”, the pair of “Sc#b” and “BSid#b” and the pair of “Sc#1” and “BSid#1” with the path loss (PL) hold value “a” are set up in the descending order of priority.  
         [0092]     Also, in the existent base station  1002 , the pair of down scrambling code “Sc#1” and base station identifier “BSid#1”, the pair of “Sc#3” and “BSid#3” with the path loss (PL) hold value “γ”, the pair of “Sc#b” and “BSid#b”, the pair of “Sc#a” and “BSid#a” and the pair of “Sc#2” and “BSid#2” with the path loss (PL) hold value “β” are set up in the descending order of priority.  
         [0093]     Further, in the existent base station  1003 , the pair of down scrambling code “Sc#1” and base station identifier “BSid#1”, the pair of “Sc#2” and “BSid#2”, the pair of “Sc#a” and “BSid#a”, the pair of “Sc#c” and “BSid#c” and the pair of “Sc#3” and “BSid#3” are set up in the descending order of priority.  
         [0094]     In the above set-up states, the setting contents for the base station  1004  are decided in the following manner. That is, at the top level of the priority order for the pair of base station identifier and down scrambling code, the pair of base station identifier and down scrambling code are set for the adjacent base station (hereinafter referred to as a first adjacent base station), to which the path loss hold value is notified, among all the pairs of base station identifier and down scrambling code reported by the existent base stations  1001  to  1003 . At its lower level, the pair of base station identifier and down scrambling code for the adjacent base station (hereinafter referred to as a second adjacent base station), to which the path loss hold value is not notified, is set up. In this example, the base stations  1001  and  1002  are the “first adjacent base stations” and the base station  1003  is the “second adjacent base station”.  
         [0095]     Herein, for the priority order between the first adjacent base stations, the first adjacent base station having the smaller path loss hold value notified from the existent base stations  1001  and  1002  is placed at higher level. In this example, the path loss values in the measurement report are “α”, “β” and “γ” in the ascending order of value. If the path loss hold values for the pair of down scrambling code and base station identifier at the same first adjacent base station are received from a plurality of base stations  100 , the average value or minimum value of path loss hold values maybe employed and compared with the path loss hold value of the other first adjacent base station.  
         [0096]     Also, for the priority order between the second adjacent base stations, the second adjacent base station having the greater number appearances among the pairs of base station identifier and down scrambling code reported by the first adjacent base station is placed at higher level. If the second adjacent base stations have the same number of appearances, the second adjacent base station with smaller path loss value of the measurement report in the pair of base station identifier and down scrambling code reported by the first adjacent base station is placed at higher level. Further, if the second adjacent base stations have smaller path loss value of the measurement report in the pair of base station identifier and down scrambling code reported by the same first adjacent base station, the second adjacent base station with higher priority order among the pairs of base station identifier and down scrambling code reported by the first adjacent base station with smaller path loss value of the measurement report is placed at higher level. That is, the setting sequence is decided in the sequence of the “number of appearances”, “base station with smaller path loss value” and “priority order”. Finally, the base station identifier and down scrambling code for the newly established base station  1004  are set as the pair of base station identifier and down scrambling code reported by that base station.  
         [0097]     In the above manner, in the newly established base station  1004 , the pair of down scrambling code “Sc#1” and base station identifier “BSid#1”, the pair of “Sc#2” and “BSid#2”, the pair of “Sc#3” and “BSid#3”, the pair of “Sc#a” and “BSid#a” and the pair of “Sc#4” and “BSid#4” are set up in the descending order of priority.  
         [0098]     By the way, the number of pairs of base station identifier and down scrambling code reported by the base station  100  is limited. Therefore, if the set number of pairs of base station identifier and down scrambling code exceeds an upper limit value (“5” in this example), the base station identifier and scrambling code report update part  110  deletes the terms having lower priority order while the term of the down scrambling code and identifier for the self base station is left. And if this upper limit value is exceeded, a setting process for the pair of base station identifier and down scrambling code is completed.  
         [0099]     With this embodiment, in the case where the pair of base station identifier and down scrambling code reported by the newly established base station is set up, if more than one pair of scrambling code and base station identifier with the same number of appearances exists among the pairs of base station identifier and down scrambling code reported at a plurality of base stations located adjacent to the cell formed by the newly established base station, the pair of base station identifier and down scrambling code reported by the newly established base station can be set up by giving the priority level to the pair of scrambling code and base station identifier.  
         [0100]     (Variant Example)  
         [0101]     While in the above embodiment, the down scrambling code not overlapping the down scrambling code of another base station is set in the CDMA system, the invention may be applied to the TDMA system or FDMA system. That is, the radio communication parameter can be set up for the pair of time slot and base station identifier reported by the newly established base station in the TDMA cellular system, or the pair of frequency band and base station identifier reported by the newly established base station in the FDMS cellular system.  
         [0102]     The invention is applicable to a multiple access system for allowing a plurality of users to make the communications at the same time by sharing a radio channel.