Abstract:
A reception sensitivity is measured at a high precision. An access terminal function portion includes the transmitter part and receiver part of a communication terminal in a radio communication system. A path switch part effects switching to connect the input ends of receivers to antennas or to terminate them. The path switch part switches the paths of a signal from a transmitter and signals toward the receivers. An access point controller adjusts a packet error rate into a predetermined range, and obtains the reception sensitivity based on the transmission power of the access terminal function portion after the adjustment.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     The present application is a continuation application of application Ser. No. 11/349,150, filed Feb. 8, 2006, now U.S. Pat. No. 7,353,020; which is a continuation-in-part of application Ser. No. 10/910,583, filed Aug. 4, 2004, now U.S. Pat. No. 7,366,508 which claims priority of Japanese Application No. 2005-139727, filed May 12, 2005 and Japanese Application No. 2003-386193, filed Nov. 17, 2003, all of the disclosure of which are hereby incorporated by reference into this application. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a radio access point testing apparatus and a method of testing a radio access point, and more particularly to a radio access point testing apparatus and a method of testing a radio access point in a mobile communication system. 
     In operating the mobile communication system, the stability of the system is one of important factors. For the stable operation of the system, it is required to prevent the occurrence of any failure leading to a system operation stop, and also to promptly detect the failure and resume the system operation in case of the occurrence of the failure. Accordingly, the failure detection circuit of the radio access point and a diagnostic method therefor are very important. 
     A transmitter and a receiver are mounted in the radio access point. The failure detection of the transmitter of them can be incarnated comparatively easily in such a way that part of a transmission main signal generated by the transmitter is branched and then monitored. In contrast, the failure detection of the receiver cannot be incarnated merely by branching and monitoring part of a reception signal. The reason therefor is that the power of the reception signal which is inputted to the receiver fluctuates every moment in accordance with an installation environment, the number of connected access terminals, etc., so a threshold value for deciding whether a reception power value is normal or abnormal cannot be determined. Accordingly, the failure detection of the receiver is generally incarnated in such a way that any known test signal is inputted to the receiver so as to monitor the reception state of the receiver. 
     The diagnostic scheme of the receiver is broadly classified into two schemes, depending upon a method of generating the test signal. One of them is a scheme wherein part of the output signal of the transmitter mounted in the same radio access point apparatus is branched so as to use the branched part as the test signal. This scheme is also called the “loopback test”. The other is a scheme wherein a test signal generator for outputting the test signal is mounted in the same radio access point apparatus. Neither of the methods, however, cannot perform a measurement in remote and on-line fashion. 
     A technique for confirming the normality of the radio access point remotely and on-line is disclosed in, for example, Patent Document 1. The technique is a method wherein a telephone within an operation center connected to a network including the radio access point apparatus, vocally communicates with a portable terminal within the access point, via the network, thereby to test the access point apparatus and the network. Besides, Patent Document 2, for example, discloses a technique wherein a similar test method has been expanded into a method of confirming the normality of a packet data call processing function, not the vocal communications. 
     [Patent Document 1] JP-A-2000-332679 
     [Patent Document 2] JP-A-2002-271280 
     SUMMARY OF THE INVENTION 
     Each of the two prior-art examples can detect the abnormality of the reception path of the radio access point apparatus, but it has the problem that a radio characteristic change such as a reception performance degradation attendant upon a slight degree of fault cannot be decided quantitatively. A further problem is that a faulty part cannot be specified. 
     In order to solve the problems, the reception sensitivity of the radio access point apparatus needs to be measured at a high precision. Besides, in performing the receiver sensitivity measurement, the influence of external noise from an antenna installation must be considered. In an installation environment of heavy external noise, the reception sensitivity is sometimes reported to be worse than the original reception sensitivity value of the access point. The reason therefor is that the external noise inputted via the antenna is superposed on the test signal, so the S/N (Signal To Noise Ratio) of the signal lowers to degrade the reception sensitivity of the access point. 
     In view of the above points, the present invention has its object to provide a radio access point testing apparatus and a method of testing a radio access point as measure a reception sensitivity at a high precision. Another object of the invention is to exclude the influence of external noise and to calibrate a measurement loop before a receiver sensitivity measurement, thereby to measure a reception sensitivity at a high precision. Still another object of the invention is to diagnose a receiver and a signal path. Yet another object of the invention is to specify a cause in a case, for example, where a receiver sensitivity measurement value as desired has not been attained. 
     In the invention, the reception sensitivity is measured by furnishing a radio access point apparatus with a test terminal called a “TAT (access terminal function portion)”. The TAT is the test terminal which is endowed with the same call processing function as that of a general access terminal. Owing to the endowment with the same call processing function as that of the general access terminal, the reception sensitivity can be measured without influence on a general service. Besides, a radio-frequency switch is connected to an antenna input end in order to exclude a measurement error ascribable to the external noise. During the receiver sensitivity measurement, the switch is set so as to cut off the section between the antenna and an access point receiver, so as to prevent the external noise from being inputted. 
     Further, the normality of the path between the TAT and the access point receiver is confirmed using the output signal of a transmitter mounted in the access point. Thus, when the receiver sensitivity measurement value as desired, for example, has not been acquired, it is permitted to specify the cause. 
     In order to incarnate these functions, the reception sensitivity of the access point is measured by the following procedure of steps in the invention, but the measurement may well be performed by an appropriate procedure of steps without being restricted to the indicated steps:
     (1) Confirmation of Normality of Path between TAT and Access point receiver   (2) Calibrations of Path loss between TAT and Access point receiver and Transmitter within TAT   (3) Receiver sensitivity measurement of Access point receiver   

     According to a first solving means of this invention, there is provided a radio access point testing apparatus comprising: 
     an access terminal function portion which includes a transmitter part and a receiver part of a communication terminal in a radio communication system, and which serves to test a radio access point; 
     either of a receiver of one loop and receivers of two loops, for receiving forward signals that are transmitted from said access terminal function portion and said communication terminal; 
     a transmitter for transmitting reverse signals that are transmitted to said access terminal function portion and said communication terminal; 
     a path switch part for effecting switching so as to connect an input end of said receiver to an antenna or to terminate the input end, and for switching paths of the signal from said transmitter and the signal toward said receiver; and 
     an access point controller which controls said access point; 
     wherein said access point controller receives a test start command, terminates the input end of said receiver by said path switch part in compliance with the command, and connects a desired one of said transmitter and said receiver with said access terminal function portion, so as to control either or both of: 
     (1) a receiver sensitivity measurement in which a packet error rate is adjusted into a predetermined range, and in which a reception sensitivity is obtained on the basis of transmission power of said access terminal function portion after the adjustment; and 
     (2) a measurement path diagnosis which acquires a first reception power value of said receiver in the case of connecting said receiver with said transmitter part of said access terminal function portion, and a second reception power value of said access terminal function portion in the case of connecting said transmitter with said receiver part of said access terminal function portion, and in which failures of said receiver and the signal path are diagnosed depending upon whether or not a difference between the first reception power value and a predetermined first reception power expectation, and a difference between the second reception power value and a predetermined second reception power expectation lie within predetermined ranges, respectively. 
     According to a second solving means of this invention, there is provided in a radio access point having an access terminal function portion which includes a transmitter part and a receiver part of a communication terminal in a radio communication system, and which serves to test a radio access point; either of a receiver of one loop and receivers of two loops, for receiving forward signals that are transmitted from the access terminal function portion and the communication terminal; a transmitter for transmitting reverse signals that are transmitted to the access terminal function portion and the communication terminal; a path switch part for effecting switching so as to connect an input end of the receiver to an antenna or to terminate the input end, and for switching paths of the signal from the transmitter and the signal toward the receiver; and an access point controller which controls the access point; 
     a method of testing the radio access point, comprising: 
     receiving a test start command; and 
     terminating the input end of said receiver by said path switch part in compliance with the test start command, and connecting a desired one of said transmitter and said receiver with said access terminal function portion, so as to control either or both of: 
     (1) a receiver sensitivity measurement in which a packet error rate is adjusted into a predetermined range, and in which a reception sensitivity is obtained on the basis of transmission power of said access terminal function portion after the adjustment; and 
     (2) a measurement path diagnosis which acquires a first reception power value of said receiver in the case of connecting said receiver with said transmitter part of said access terminal function portion, and a second reception power value of said access terminal function portion in the case of connecting said transmitter with said receiver part of said access terminal function portion, and in which failures of said receiver and the signal path are diagnosed depending upon whether or not a difference between the first reception power value and a predetermined first reception power expectation, and a difference between the second reception power value and a predetermined second reception power expectation lie within predetermined ranges, respectively. 
     Incidentally, the receiver sensitivity measurement comprises by way of example: 
     that an access point controller sets a path switch part so as to connect a receiver with a transmitter of an access terminal function portion; 
     that the access terminal function portion establishes a calling connection state with a predetermined device through a modulation/demodulation process portion, and transmits packets; that the access point controller obtains a packet error rate; 
     that the access point controller commands the access terminal function portion to alter transmission power, in accordance with the obtained packet error rate; 
     that the access terminal function portion alters the transmission power in compliance with the command from the access point controller; 
     that the access terminal function portion transmits an altered transmission power value to the access point controller; 
     that the access point controller receives the transmission power value, and stores the received transmission power value in a storage unit; 
     that the access point controller obtains a packet error rate again; 
     that the access point controller judges if the obtained packet error rate lies within a predetermined range, and that it repeats commanding the access terminal function portion to alter transmission power and then receiving and storing a transmission power value until the packet error rate comes to lie within the predetermined range; 
     that the access point controller calculates a reception sensitivity on the basis of the transmission power value at a time when the packet error rate lies within the predetermined range; and 
     that the access point controller stores a test result which contains the calculated reception sensitivity and/or a failure decision result based on the reception sensitivity, in the storage unit, or transmits the test result to a maintenance device. 
     According to the present invention, it is possible to provide a radio access point testing apparatus and a method of testing a radio access point as measure a reception sensitivity at a high precision. Besides, according to the invention, the influence of external noise is excluded, and a measurement loop is calibrated before the measurement of the reception sensitivity, whereby the reception sensitivity can be measured at a high precision. According to the invention, a receiver and a signal path can be diagnosed. Moreover, according to the invention, in a case, for example, where a receiver sensitivity measurement value as desired has not been obtained, the cause of the situation can be specified. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a radio access point according to an embodiment of the present invention; 
         FIG. 2  is a detailed configurational diagram of the path switch part and test function unit of sector- 1  in the invention; 
         FIG. 3  is a diagram (1) for explaining a radio signal path in the case of measuring the reception sensitivity of the loop- 0  of the sector- 1  in the invention; 
         FIG. 4  is a diagram (2) for explaining a radio signal path in the case of measuring the reception sensitivity of the loop- 0  of the sector- 1  in the invention; 
         FIG. 5  is a diagram (3) for explaining a radio signal path in the case of measuring the reception sensitivity of the loop- 0  of the sector- 1  in the invention; 
         FIG. 6  is a diagram (4) for explaining a radio signal path in the case of measuring the reception sensitivity of the loop- 0  of the sector- 1  in the invention; 
         FIG. 7  is a diagram for explaining a sequence in the case of performing a measurement path diagnosis in the invention; 
         FIG. 8  is a diagram for explaining a sequence in the case of configuring a measurement system in the invention; 
         FIG. 9  is a diagram for explaining a sequence in the case of performing the receiver sensitivity measurement in the invention; 
         FIG. 10  is a block diagram in the case of performing a reception power measurement in the invention; 
         FIG. 11  is a diagram for explaining receiver diagnoses in the invention; 
         FIG. 12  is an example of a receiver correcting table in the invention; and 
         FIG. 13  is a flow chart of normality diagnoses. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will now be described with reference to the drawings by exemplifying a radio access point of 3-sector configuration which includes a transmitter of one loop and receivers of two loops per sector, and which incarnates diversity reception. 
       FIG. 1  is a configurational diagram of the radio access point. Included in the radio access point  100  are three sectors (sector- 1   110 , sector- 2   111  and sector- 3   112 ), a test function unit  113 , a line interface portion  114  and an access point controller  115 . 
     The signal processing unit (sector- 1 )  110  includes a radio signal transmission/reception portion  120  and a modulation/demodulation process portion  121 , and a loop- 0  antenna  116  shared by transmission and reception and a loop- 1  antenna  117  for reception, for example, are connected to this signal processing unit. The radio signal transmission/reception portion  120  includes a path switch part  132  for switching transmission/reception paths, and the transmitter  133  of one loop, as well as the receivers of two loops (receiver- 0   134  and receiver- 1   135 ). Further, the radio signal transmission/reception portion  120  includes a DUP (duplexer)  130  which separates a reverse radio signal  150  and a forward radio signal  151 , and a BPF (band-pass filter)  131  which limits the pass band of the forward radio signal  151 . Incidentally, the number of sectors is not limited to three, but one sector or an appropriate number of sectors may well be included. Besides, the receivers and the transmitter(s) may well be disposed in appropriate numbers of loops. 
     The transmitter  133  converts a reverse baseband signal  155  inputted from a modulator  136 , into a reverse radio signal  152 . The receiver- 0   134  receives the forward radio signal  151  transmitted by an access terminal  101 , through the DUP  130  (as a signal  153 ), so as to convert the received signal into a forward baseband signal  156 . On the other hand, the receiver- 1   135  receives the forward radio signal  151  transmitted by the access terminal  101 , through the BPF  131  (as a signal  154 ), so as to convert the received signal into a forward baseband signal  157 . Incidentally, since the configuration of each of the sector- 2   111  and sector- 3   112  may be identical to the configuration of the sector- 1   110 , it shall be omitted from description. 
     The modulation/demodulation process portion  121  includes the modulator  136  and a demodulator  137 , and it modulates and demodulates data. The line interface portion  114  is the interface between the radio access point  100  and a network  102 . The access point controller  115  has the functions of monitoring and controlling the radio access point  100 . The test function unit  113  includes, for example, an access terminal function portion  126  and a test function controller  127 . Incidentally, the practicable configuration of the test function unit  113  will be described later. 
     A maintenance terminal  103  is connected to the access point controller  115  via the network  102 , and it has the functions of remotely monitoring and controlling the radio access point  100 . A test server  104  is a server for testing, and the access terminal function portion  126  in the test function unit  113  connects this test server via the network  102 . 
       FIG. 2  is a detailed configurational diagram of the path switch part and the test function unit. Besides,  FIGS. 3-6  are diagrams (1)-(4) for explaining radio signal paths, respectively. A receiver sensitivity measurement according to the embodiment of the invention will be described with reference to  FIGS. 2-6 . Incidentally, although  FIG. 2  illustrates the internal configuration of the sector- 1   110 , each of the sector- 2   111  and the sector- 3   112  may be identical in configuration to the sector- 1   110  and shall therefore be omitted from description. 
     In this embodiment, the test function unit  113  is mounted in the radio access point  100 , and the path switch part  132  is mounted in the radio signal transmission/reception portion  120 . The path switch part  132  includes, for example, three CPLs (directional couplers) and six SWs (radio-frequency switches). Incidentally, the CPLs and the SWs may well be disposed in appropriate numbers without being limited to the above numbers. 
     The CPL  201  (second directional coupler) connects the transmitter is  133 , the DUP  130  (or a path to the antenna) and the SW  202  (or a path to the test function unit) to one another. Besides, the CPL  204  (first directional coupler) connects the SW  205  (the receiver- 0  or the transmitter), the SW  203  (a path to the antenna or a terminating part for termination) and the SW  209  (a path to the access terminal function portion) to one another. The CPL  207  connects the SW  208  (the receiver- 1  or the transmitter), the SW  206  (a path to the antenna or a terminating part for termination) and the SW  209  (the path to the access terminal function portion) to one another. 
     The CPL  201  extracts part of a reverse radio signal  221  so as to output the extracted part to the test function unit  113 . The CPL  204  extracts part of the reverse radio signal extracted by the CPL  201 , so as to output the extracted part to the test function unit  113 . Besides, the CPL  204  couples a forward test signal transmitted from the test function unit  113 , to a loop- 0  forward main signal path  227 , so as to output the forward test signal to the receiver- 0   134 . The CPL  207  extracts part of the reverse radio signal extracted by the CPL  201 , so as to output the extracted part to the test function unit  113 . Besides the CPL  207  couples the forward test signal transmitted from the test function unit  113 , to a loop- 1  forward main signal path  232 , so as to output the forward test signal to the receiver- 1   135 . 
     The SW  203  switches the input terminal of the receiver- 0   134  so as to be connected to the loop- 0  antenna  116  through the DUP  130 , or to be terminated (connected to the terminating part). Besides, the SW  206  switches the input terminal of the receiver- 1   135  so as to be connected to the loop- 1  antenna  117  through the BPF  131 , or to be terminated (connected to the terminating part). The SW  202  switches the part  221  of the reverse radio signal extracted by the CPL  201 , so as to be outputted to the test function unit  113 , to be outputted to the loop- 0  forward main signal path  227 , or to be outputted to the loop- 1  main signal path  232 . 
     The SW  205  switches, for example, the CPL  204  so as to be connected to the receiver- 0   134 , or to be connected to the transmitter  133 . The SW  208  switches, for example, the CPL  207  so as to be connected to the receiver- 1   135 , or to be connected to the transmitter  133 . By way of example, the SW  205  effects switching so as to output the forward test signal transmitted from the test function unit  113 , to the receiver- 0   134  (a signal path  303  in  FIG. 4 ), or to output the reverse radio signal extracted by the CPL  201 , to the test function unit  113  (a signal path  304  in  FIG. 5 ). The SW  208  effects switching so as to output the forward test signal transmitted from the test function unit  113 , to the receiver- 1   135 , or to output the reverse radio signal extracted by the CPL  201 , to the test function unit  113 . The SW  209  switches the test function unit  113  so as to be connected to the receiver- 0   134 , or to be connected to the receiver- 1   135 . 
     In an ordinary operation mode (a non-test mode), as shown in  FIG. 3  is by way of example, the SW  203  is set on the side of the loop- 0  antenna  116 , and the SW  205  on the side of the receiver- 0   134 . Besides, the SW  206  is set on the side of the loop- 1  antenna  117 , and the SW  208  on the side of the receiver- 1   135 . That is, a loop- 0  forward radio signal and a loop- 1  forward signal are respectively inputted to the demodulator  137  through a signal path  301  and a signal path  302 . 
     The test function unit  113  includes the access terminal function portion  126 , the test function controller  127 , three switches  210 ,  211  and  213 , and a DUP  212 . Incidentally, the switches may well be disposed in an appropriate number without being restricted to the above number. Besides, the test function unit  113  may well further include a forward link attenuator  222  and a reverse link attenuator. The access terminal function portion  126  is a testing terminal which has functions equivalent to those of the access terminal  101  which a general user uses. By way of example, the access terminal function portion  126  includes a transmitter part  214  and a receiver part  215 . The test function controller  127  controls the access terminal function portion  126 , and has the function of setting the three switches mounted in the test function unit  113 . The SWs  210  and  211  have the functions of switching the sectors to-be-tested. Besides, the SW  213  switches the path of the reverse radio signal outputted by the transmitter  133  of the access point, between a signal path which extends via the forward signal path and a signal path which does not extend via the same. The DUP  212  separates the reverse test signal and the forward test signal. 
       FIG. 10  is a configurational diagram of the receiver. By way of example, the receiver- 0   134  of the radio signal transmission/reception portion  120  includes an LNA (low-noise amplifier)  601  which amplifies a received signal at a low distortion, an ISO (isolator)  602 , an AMP (amplifier)  603 , a BPF (low-pass filter)  604  which attenuates unnecessary signal components other than the particular band of the receiver, and an AGC-AMP (automatic gain control amplifier)  605 . Besides, the receiver may well include, for example, a memory (such as ROM) which is readable from the access point controller  115 . The AGC-AMP  605  has the function of varying the gain of the amplifier in accordance with input power in order that signal power to be inputted to the demodulator  137  may be held constant. The receiver can measure a reception power value by using the gain value of the AGC-AMP  605 . 
     As an example, let&#39;s consider a case where the gain of the AGC-AMP  605  is subjected to a closed loop control in order that the signal power which is inputted to the demodulator  137  may become 0 (zero) dBm. Among the components constituting the receiver, only the AGC-AMP  605  is of variable gain, and the other components (for example, the LNA  601  and the AMP  603 ) are of fixed gains. Accordingly, when the total of the gain values of all the components except the AGC-AMP  605  is denoted as a “receiver fixed gain”, the following formula holds:
 
(Reception power)+(Receiver fixed gain)+(Gain of  AGC - AMP )=0 dBm
 
That is,
 
(Reception power)=−(Receiver fixed gain)−(AGC-AMP gain)
 
Since the receiver fixed gain is a known value, the reception power can be measured in accordance with the above formula. Incidentally, each of the receiver- 1   135  and the receiver part  215  of the access terminal function portion  126  is similar in configuration to the receiver- 0   134 . Accordingly, the measurement of the reception power of each receiver can be incarnated by the same scheme.
 
(Measurement Path Diagnosis)
 
       FIG. 7  is a diagram for explaining a sequence in the case of performing a measurement path diagnosis. A method of diagnosing the receiver- 0  will be described with reference to  FIG. 7 . Incidentally, since the other receivers can be diagnosed by the same steps of procedure, they shall be omitted from description. Besides, signals “Ack” replying to requests shall be omitted because they are ordinarily existent. 
     The measurement path diagnosis is started, for example, in such a way that a maintenance engineer inputs an instruction for the measurement path diagnosis, to the maintenance terminal  103 . The measurement-path-diagnosis execution instruction contains measurement conditions such as the designation of the access point for the measurement and the designations of the sector to-be-handled and the receiver to-be-handled. Here, description will be made assuming the diagnosis of the loop- 0  of the sector- 1  in the access point  100 . Incidentally, apart from the input by the maintenance engineer, the measurement path diagnosis may well be started at an appropriate timing, for example, in such a way that the measurement is started at a predetermined time in accordance with a schedule stipulated beforehand. 
     At a step  701 , the maintenance terminal  103  notifies a diagnosis start instruction containing the designated measurement conditions, to the access point controller  115  of the designated radio access point  100 . Incidentally, the designations of the sector and the reception loop to-be-measured may well be omitted so as to successively conduct the tests of all the receivers of the radio access point  100 . 
     At a step  702 , the access point controller  115  receives the diagnosis start instruction, and it commands the test function controller  127  to turn ON the power source of the access terminal function portion  126  in compliance with the received instruction. At a step  703 , the test function controller  127  turns ON the power source of the access terminal function portion  126 . 
     At a step  704 , the access point controller  115  commands the path switch part  132  and the test function unit  113  to set the switches (SW settings ( 2 )). At a step  705 , the switches of the path switch part  132  and test function unit  113  are set so as to pass through signal paths  302  and  303  in  FIG. 4 . By way of example, the SW  203  is set onto the terminating side, and the SWs  205  and  209  are respectively set onto the receiver- 0  sides. Besides, the SW  210  of the test function unit  113  is set onto the sector- 1  side. Incidentally, how the individual SWs are set can be stipulated in accordance with SW setting commands beforehand. The signal path  302  is a path in the ordinary operation mode. Accordingly, the receiver- 1   135  which is connected to the loop- 1  antenna  117  does not incur the stop of service. 
     At a step  706 , the access point controller  115  commands the access terminal function portion  126  to transmit a test signal. The transmission command contains, for example, the settings of transmission power and a transmission frequency. Incidentally, the maintenance engineer may well be permitted to designate the power and the frequency from the maintenance terminal  103 . At a step  707 , the transmitter part  214  of the access terminal function portion  126  transmits the test signal. By way of example, the access terminal function portion  126  can transmit packets to the test server  104  by executing ping. Incidentally, apart from the ping, an appropriate command or application for transmitting the packets may well be executed. The transmitted signal passes through the signal path  303  in  FIG. 4 , and it is inputted to the receiver- 0   134 . The test signal is destined for, for example, the test server  104 , and the receiver- 0   134  and the demodulator  137  can process the test signal likewise to an ordinary reception signal. At a step  708 , the access terminal function portion  126  reports the transmission power (TAT transmission power value) to the access point controller  132 . The transmission power is reported, for example, after the test signal has been transmitted for a predetermined time period or in a predetermined quantity. 
     At a step  709 , the access point controller  115  requests the receiver- 0   134  to report reception power. At a step  710 , the receiver- 0   134  measures the reception power of the test signal. At a step  711 , the receiver- 0   134  reports the measured value of the reception power (access point reception power value) to the access point controller  115 . The access point controller  115  records the reported TAT transmission power value and access point reception power value in a RAM  123  at an appropriate timing (hereinbelow, the reported values shall be written as “measurement values (1)”). 
     At a step  712 , commands for setting the switches are sent from the access point controller  115  to the path switch part  132  and test function unit  113  (SW settings ( 3 )). At a step  713 , the switches of the path switch part  132  and test function unit  113  are set so as to pass through the path  304  in  FIG. 5 . By way of example, the SW  202  is set onto the side of the forward main signal path  227 , and the SW  205  onto the side of the transmitter  133 . Incidentally, the SWs  203 ,  209  and  210  are in the same states as in  FIG. 4 . Besides, the SW  213  of the test function portion  113  is set onto the side of the forward main signal path  227 . 
     At a step  714 , the access point controller  115  requests the transmitter  133  to report the transmission power of this transmitter  133  (transmission power report request). At a step  715 , the transmitter  133  reports the transmission power of this transmitter  133  (access point transmission power value) to the access point controller  115  in compliance with the transmission power report request. Either the transmission power for a predetermined time period or the instantaneous value of the transmission power may be reported as the transmission power value. 
     At a step  716 , the access point controller  115  requests the receiver part  215  to report a reception power value. At a step  717 , the receiver part  215  measures reception power which is being received. At a step  718 , the receiver part  215  reports the measured reception power value (TAT reception power value) to the access point controller  115 . The access point controller  115  records the reported access point transmission power value and TAT reception power value in the RAM  123  (hereinbelow, the reported values shall be written as “measurement values (2)”). 
     At a step  719 , the access point controller  115  diagnoses the normality of the path between the access terminal function portion  126  and the receiver- 0   134 , by using the measurement values (1) and (2) recorded in the RAM  123 . The diagnosis is made in accordance with the procedure of steps stated below. 
     Initially, the normalities of the transmitter  133  of the access point and the transmitter part  214  within the access terminal function portion  126  are diagnosed using the access point transmission power value and TAT transmission power value which are recorded in the RAM  123 . The access point controller  115  compares the access point transmission power value with the transmission setting power of the transmitter  133 . When the difference between both the power values lies within a prescribed value (predetermined range), the transmitter  133  is diagnosed to be normal, and when the difference lies outside the prescribed value, the transmitter  133  is diagnosed to be abnormal. Incidentally, the transmission setting power of the transmitter  133  can be managed by, for example, the access point controller  115 . Alternatively, the transmission setting power may well be acquired from another appropriate management portion or from the transmitter. 
     The access point controller  115  compares the TAT transmission power value with the TAT transmission setting power of the transmitter part  214 . When the difference between both the power values lies within a prescribed value, the transmitter part  214  is diagnosed to be normal, and when the difference lies outside the prescribed value, the transmitter part  214  is diagnosed to be abnormal. Incidentally, the value set at the step  706  can be employed as the TAT transmission setting power. In a case where the transmitter  133  and/or the transmitter part  214  have/has been diagnosed to be abnormal, the access point controller  115  notifies the contents of the abnormality to the maintenance terminal  103  without executing later steps, whereupon the test is ended. The steps to be stated below will be described assuming that the transmitters  133  and  214  are normal. 
     Subsequently, the normalities of the signal path  304 , the receiver- 0   134  and the receiver part  215  in the access terminal function portion  126  are diagnosed using the access point reception power value and TAT reception power value which have been recorded in the RAM  123 . The expected value or expectation of the access point reception power value and that of the TAT reception power value can be computed as follows:
 
(Access point reception power expectation)=(TAT transmission power value)−(Path loss)
 
(TAT reception power expectation)=(Access point transmission power value)−(Path loss)
 
Here, the TAT transmission power value and the access point transmission power value are measured values, and they have been recorded in the RAM  123 . Further, the path loss is a known value (design value). Therefore, the expected values or expectations of the access point reception power value and TAT reception power value can be computed using the above values. Since, however, error factors exist in the expected values on account of the individual dispersions of the components, a deciding threshold value is provided and is set at, for example, ±3 dB. When the differences between the expected values and the reception power values recorded in the RAM  123  lie within ±3 dB, the components are decided to be normal, and when the differences exceed ±3 dB, the components are decided to be abnormal. Using the decided results, the normalities of the signal path  304 , the receiver- 0   134  and the receiver part  215  in the access terminal function portion  126  are diagnosed as stated below.
 
       FIG. 13  is a flow chart of the normality diagnoses. Now, the normality diagnoses of the signal path, the receiver- 0   134  and the receiver part  215  in the access terminal function portion  126  will be described with reference to  FIG. 13 . 
     First, the access point controller  115  diagnoses the transmitters (S 101 ). Since the details of the transmitter diagnoses are as stated above, they shall be omitted from description. Subsequently, the access point controller  115  obtains the expected value of the access point reception power and that of the TAT reception power. By way of example, the access point controller  115  reads out the TAT transmission power value, the access point transmission power value and the path loss from the RAM  123 , and it obtains the expected values of the access point reception power and TAT reception power in accordance with the above formulae (S 103 ). 
     Subsequently, the access point controller  115  judges the signal paths  303  and  304 , access terminal function portion  126  and receiver part  215  to be normal (S 109 ), in a case where the difference between the access point reception power value reported at the step  718  and the expected value of the access point reception power lies within a first range (for example, ±3 dB) (“YES” at S 105 ), and where the difference between the TAT reception power value reported at the step  711  and the expected value of the TAT reception power lies within a second range (for example, ±3 dB) (“YES” at S 107 ). This case is denoted as “Case- 1 ”. 
     Subsequently, the access point controller  115  diagnoses the receiver part  215  of the access terminal function portion  126  to be abnormal (S 11 ), in a case where the difference between the access point reception power value and the expected value of the access point reception power lies within the first range (“YES” at S 105 ), and where the difference between the TAT reception power value and the expected value of the TAT reception power lies outside the second range (“NO” at S 107 ). In this case, the access point reception power value is normal, and hence, the signal path  303  (including a part common to the path  304 ) is normal. Further, the transmitter  133  of the access point is normal in view of the step S 101 . Accordingly, the receiver part  215  of the access terminal function portion  126  is diagnosed to be abnormal. This case is denoted as “Case- 2 ”. 
     Subsequently, the access point controller  115  diagnoses the receiver  134  to be abnormal (S 115 ), in a case where the difference between the access point reception power value and the expected value of the access point reception power lies outside the first range (“NO” at S 105 ), and where the difference between the TAT reception power value and the expected value of the TAT reception power lies within the second range (“YES” at S 113 ). This case is the case of deciding the access point reception power value to be abnormal, and the TAT reception power value to be normal. In this case, the TAT reception power value is normal, and hence, the signal path  304  (including the part common to the path  303 ) is normal. Further, the transmitter part  214  of the access terminal function portion  126  is normal in view of the step S 101 . Accordingly, the receiver- 0   134  is diagnosed to be abnormal. This case is denoted as “Case- 3 ”. 
     In a case where the difference between the access point reception power value and the expected value of the access point reception power lies outside the first range (“NO” at S 105 ), and where also the difference between the TAT reception power and the expected value of the TAT reception power lies outside the second range (“NO” at S 113 ), the access point controller  115  can judge the paths to be abnormal, or both the receiver  134  of the access point and the receiver part  215  of the access terminal function portion to be abnormal. Besides, diagnoses can be made in more detail as stated below. 
     The access point controller  115  judges if the difference between the value of the access point reception power and the expected value thereof is equal to or substantially equal to the difference between the value of the TAT reception power and the expected value thereof (S 117 ). Incidentally, regarding the judgment on the substantial equality, by way of example, when both the differences have a difference lying within a predetermined threshold value, they may well be judged to be substantially equal. When the two differences are substantially equal (“YES” at S 117 ), the access point controller  115  can make the diagnosis that the path loss of the signal path  304  is excessive (S 119 ). The reason therefor is that, in the case of the excessive path loss, both the access point reception power value and the TAT reception power value become smaller than the expected values in correspondence with the excessive loss. This case is denoted as “Case- 4 ”. 
     In a case where the difference between the access point reception power value and the expected value of the access point reception power, and the difference between the TAT reception power value and the expected value of the TAT reception power lie outside the first and second ranges, respectively (“NO” at S 105  and “NO” at S 113 ), where the difference between the value of the access point reception power and the expected value thereof is not equal to the difference between the value of the TAT reception power and the expected value thereof (“NO” at S 117 ), and where both the access point reception power value and the TAT reception power value are judged to have lower-limit values (“YES” at S 121 ), the access point controller  115  can make the diagnosis that the signal path  304  is disconnected (S 123 ). The reason therefor is that, in the case of the disconnection of the path itself, quite no signal is inputted to the receiver- 0   134  and the receiver part  215  of the access terminal function portion  126 , so both the access point reception power value and the TAT reception power value become the lower-limit values. Incidentally, the lower-limit values can be stipulated beforehand. This case is denoted as “Case- 5 ”. 
     In a case where the difference between the access point reception power value and the expected value of the access point reception power, and the difference between the TAT reception power value and the expected value of the TAT reception power lie outside the first and second ranges, respectively (“NO” at S 105  and “NO” at S 113 ), where the difference between the value of the access point reception power and the expected value thereof is not equal to the difference between the value of the TAT reception power and the expected value thereof (“NO” at S 117 ), and where neither of the access point reception power value and the TAT reception power value is judged to have the lower-limit value (“NO” at S 121 ), the access point controller  115  can diagnose the signal path  304  to be normal, and both the receiver- 0   134  and the receiver part  215  of the access terminal function portion  126  to be abnormal (S 125 ). This case is denoted as “Case- 6 ”. 
     Incidentally, regarding the Case- 4  through Case- 6 , by way of example, even when the difference between the value of the access point reception power and the expected value thereof is equal to the difference between the value of the TAT reception power and the expected value thereof at the step S 117 , both the receivers might be abnormal. By way of example, accordingly, in any of the Case- 4  through Case- 6 , the access point controller  115  judges the path to be abnormal, or both the receiver- 0   134  and the receiver part  215  of the access terminal function portion to be abnormal, and it may well render a judgment to the effect that the radio access point might be in any of the Case- 4  through Case- 6  stated above. 
       FIG. 11  is a diagram for explaining the diagnosing procedure of steps. The diagnosing procedure of steps will be described by exemplifying numerical values, with reference to  FIG. 11 . By way of example, the deciding threshold values (first and second ranges) are set at ±3 dB. Besides, assuming, for example, that the TAT transmission power value is −30 dBm and that the path loss is 40 dBm, the expected value of the access point reception power becomes −70 dBm in view of the above formula. Likewise, assuming, for example, that the access point transmission power value is −30 dBm and that the path loss is 40 dBm, the expected value of the TAT reception power becomes −70 dBm in view of the above formula. Although the two expected values will be described as the same values here, they may well be different values. 
     The Case- 1  corresponds to a case, for example, where the access point reception power value is −72 dBm, where the expected value of the access point reception power is −70 dBm, where the measured value of the TAT reception power is −71 dBm, and where the expected value of the TAT reception power is −70 dBm. The difference between the access point reception power values becomes −2 dBm, which lies within the deciding threshold value, and the difference between the TAT reception power values becomes −1 dBm, which lies within the deciding threshold value. Therefore, the receivers  134  and  215  and the path are diagnosed to be normal. 
     The Case- 2  corresponds to a case, for example, where the access point reception power value is −72 dBm, where the expected value of the access point reception power is −70 dBm, where the measured value of the TAT reception power is −80 dBm, and where the expected value of the TAT reception power is −70 dBm. The difference between the access point reception power values becomes −2 dBm, which lies within the deciding threshold value, and the difference between the TAT reception power values becomes −10 dBm, which lies outside the deciding threshold value. Therefore, the receiver part  215  is diagnosed to be faulty. 
     The Case- 3  corresponds to a case, for example, where the access point reception power value is −85 dBm, where the expected value of the access point reception power is −70 dBm, where the measured value of the TAT reception power is 69 dBm, and where the expected value of the TAT reception power is −70 dBm. The difference between the access point reception power values becomes −15 dBm, which lies outside the deciding threshold value, and the difference between the TAT reception power values becomes 1 dBm, which lies within the deciding threshold value. Therefore, the receiver  134  is diagnosed to be faulty. 
     The Case- 4  corresponds to a case, for example, where the deciding threshold values are similarly set at ±3 dBm, where the access point reception power value is −82 dBm, where the expected value of the access point reception power is −70 dBm, where the measured value of the TAT reception power is −83 dBm, and where the expected value of the TAT reception power is −70 dBm. The difference between the access point reception power values becomes −12 dBm, which lies outside the deciding threshold value, and the difference between the TAT reception power values becomes −13 dBm, which lies outside the deciding threshold value. The difference between the access point reception power values is substantially equal to the difference between the TAT reception power values. Therefore, the path  304  is diagnosed to undergo the excessive loss. Incidentally, the numerical value examples of the Case- 5  and Case- 6  shall be omitted. 
     In this way, the normalities of the receivers are diagnosed. Although the diagnoses can be made before the receiver sensitivity measurement by way of example, they are not restricted thereto, but they may well be made after the receiver sensitivity measurement. Incidentally, the deciding threshold values can also be set at the start of the diagnoses. Besides, the deciding threshold values need not always be set, but the maintenance engineer can also render decisions in such a way that the measured values (1) and (2) are transmitted to the maintenance terminal  103  so as to be displayed on the display unit of this maintenance terminal  103 . Further, the computations of the differences between the measured values and the expected values can be performed on either of the side of the access point controller and the side of the maintenance terminal. 
     (Calibrations) 
       FIG. 8  is a sequence diagram for performing the calibrations of each measurement loop. The calibrations of the measurement loop will be described with reference to  FIG. 8 . Incidentally, a process to be stated below may be executed after the above step  719 , or it may well be executed upon receiving a test start command for performing the calibrations of the measurement loop, from the maintenance terminal  103 . 
     At a step  720 , the access point controller  115  commands the path switch part  132  and the test function unit  113  to set the switches (SW settings ( 4 )). At a step  721 , in compliance with the SW setting command, the switches of the path switch part  132  and test function unit  113  are set so as to pass through, for example, the path  303  in  FIG. 4 . 
     At a step  722 , the access point controller  115  commands the access terminal function portion  126  to transmit a test signal. The test signal may well contain, for example, the designations of a transmission level and a frequency. By way of example, the test signal designates the transmission level of −70 dBm and the frequency of f 2 . Incidentally, the level and frequency of the test signal may well be designated from the maintenance terminal  103  by the maintenance engineer. At a step  723 , the transmitter part  214  of the access terminal function portion  126  transmits the test signal. The transmitted signal passes through the path  303  in  FIG. 4 , and is inputted to the receiver- 0   134 . At a step  724 , the access terminal function portion  126  reports transmission power to the access point controller  115 . The access point controller  115  stores the reported transmission power in the RAM  123 . 
     At a step  725 , the access point controller  115  requests the receiver- 0   134  to report a reception power value. At a step  726 , the receiver- 0   134  measures power being received, in compliance with the report request. At a step  727 , the receiver- 0   134  reports the measured value of the received power to the access point controller  115 . The access point controller  115  stores the reported received power in the RAM  123 . 
     At a step  728 , the access point controller  115  reads the correction value of each individual receiver from a ROM which is mounted in the receiver  134 . By way of example, the correction value corresponding to the frequency f 2  is read. 
       FIG. 12  shows a configurational example of a receiver correcting table which is included in each receiver. By way of example, correction values are stored for respective frequencies beforehand. Each of the correction values indicates, for example, the error between an actual reception power value in the receiver and the reported reception power value. Incidentally, although the correction values for the receivers of the loop- 0  and loop- 1  are listed in the single table in  FIG. 12 , the receivers of the individual loops may well include the correction values for the respective frequencies separately. 
     At a step  729 , the access point controller  115  calibrates a section from the test function unit  113  to the input end of the receiver- 0   134 , on the basis of the value reported from the receiver- 0   134 . A method for the calibrations will be described below.
     (1) The reception power value at the receiver-O end is computed in accordance with the following computational formula:
 
(Actual power value at Receiver-0 end)=(Reported value of Reception power)+Correction value
   (2) The transmitter part  214  mounted in the access terminal function portion  126 , and the reception path are calibrated on the basis of the computed value of the above step (1).   

     There will be described an example in the case where the transmission power of the access terminal function portion  126  is −30 dBm, while the reported value of the reception power of the receivers  134  is −72 dBm, and where the correction value for the frequency f 2  and the loop- 0  to-be-handled is −0.3 in view of the receiver correcting table shown in  FIG. 12 . First, the access point controller  115  computes the power at the receivers end.
 
(Actual power value at Receiver-0 end)=Reception power+Correction value=−72+(−0.3)=−72.3 dBm
 
The actual reception power at the receivers end becomes −72.3 dBm in accordance with the above formula.
 
     Subsequently, the access point controller  115  calibrates the access terminal function portion  126  and the reception loop. First, the access point controller  115  takes the difference between the transmission power of the access terminal function portion  126  and the actual reception power at the receiver end. The transmission power of the access terminal function portion  126  is −30 dBm, and the actual power at the receivers end is −72.3 dBm, so that the difference between the two values becomes 42.3 dBm. This is the loss value of the transmitter part  214  of the access terminal function portion  126  and the signal path by way of example. Assuming that a predetermined path loss stored in, for example, a memory is 40 dBm, a deviation of 2.3 dBm is involved. 
     When the access terminal function portion transmits power at −27.7 dBm which is 2.3 dBm (calibration value) higher, inclusive of the calibration of the path, the actual power at the receiver- 0  end becomes −70 dBm. In this way, the measurement path is calibrated. Besides, the access point controller  115  may well store the obtained loss value and/or a configurational value in a memory or the like. By way of example, the access point controller  115  may use the stored loss value instead of a path loss value in a receiver sensitivity measurement to be described later, or it may well make a transmission power value to-be-designated higher in correspondence with the stored calibration value, at the time of a packet transmission start command. 
     (Receiver Sensitivity Measurement) 
       FIG. 9  is a sequence diagram of the receiver sensitivity measurement. Incidentally, a process to be stated below may be executed after the above step  729 , or it may well be executed upon receiving a test start command for performing the receiver sensitivity measurement, from the maintenance terminal  103 . 
     At a step  829 , the access point controller  115  sets the individual SWs as shown in  FIG. 6  by way of example. At a step  730 , the access point controller  115  commands the test function controller  127  to start a calling connection. At a step  731 , the test function controller  127  dials up the test server  104  and establishes a calling connection state. Incidentally, connection destination information items such as the dial number of the test server  104  can be stored in an appropriate memory within the access point controller  115  or test function unit  113  beforehand. At a step  732 , the access terminal function portion  126  gives the access point controller  115  “TAT-State alteration notification” which contains information indicating that calling has been connected. Incidentally, the access terminal function portion  126  and the access point controller  115  are capable of transmitting and receiving data therebetween through, for example, the test function controller. 
     At a step  733 , the access point controller  115  commands the access terminal function portion  126  to start packet transmission (packet transmission start command). The packet transmission start command can contain, for example, the calibrated power value stated before (for example, −27.7 dBm). At a step  734 , the access terminal function portion  126  having received the packet transmission start command starts the packet transmission to the server. At a step  735 , the access terminal function portion  126  gives the access point controller  115  “TAT-State alteration notification” which contains information indicating that the packet transmission has been started. 
     At a step  736 , the access point controller  115  requests the access terminal function portion  126  to report the transmission power of this access terminal function portion  126  (transmission power report request). At a step  737 , in compliance with the transmission output report request, the access terminal function portion  126  reports its transmission power to the access point controller  115 . By way of example, the access terminal function portion  126  reports the mean value of the transmission power for a predetermined time period before or after the reception of the transmission power report request. Alternatively, it may well report the instantaneous value of the transmission power at the time of the reception of the transmission power report request. The access point controller  115  stores the reported transmission power value P 1  in the memory. 
     At a step  738 , the access point controller  115  acquires a PER (packet error rate). The PER can be measured as stated below by way of example. Each of the sectors has the function of requesting the access terminal function portion  126  to retransmit packets which cannot be demodulated due to errors, in demodulating a forward signal transmitted from this access terminal function portion  126 . It is accordingly possible to count the number of the packets for which the re-transmission request was made on account of the errors (hereinbelow, called the “number of the error packets”), and the number of packets which were normally received, among the packets of the forward signal as were received by each sector. Each sector counts the number of the error packets and the number of the packets normally received, and calculates the PER in accordance with the following formula:
 
 PER [%]=(Number of Error packets)/(Total number of Received packets)
 
Incidentally, the total number of received packets is the total of the number of the error packets and the number of the packets normally received.
 
     The access point controller  115  requests, for example, the sector- 1  (for example, the demodulator  137 ) to report the value of the PER, and it can acquire the PER transmitted in compliance with the request. Incidentally, the access point controller  115  may well acquire the number of the error packets and the number of the packets normally received (or the total number of the received packets), so as to obtain the PER in accordance with the above formula. Besides, the access point controller  115  stores the acquired PER in the memory. 
     At a step  739 , the access point controller  115  commands the access terminal function portion  126  to alter the transmission power, in accordance with the PER (transmission power alteration command). By way of example, in a case where the measured PER is lower than prescribed threshold values, the access point controller  115  commands the access terminal function portion  126  to lower the transmission power, and conversely, in a case where the PER is higher than the prescribed threshold values, the former  115  commands the latter  126  to heighten the transmission power. Incidentally, the transmission power of the access terminal function portion  126  may well be altered by changing the attenuation magnitude of the forward link attenuator  222  in a state where this transmission power is once fixed at its value at the above calibration. 
     At a step  740 , the access terminal function portion  126  alters the transmission power in compliance with the command from the access point controller  115 . At a step  741 , the access terminal function portion  126  reports the altered transmission power to the access point controller  115 . At a step  742 , the access point controller  115  acquires the PER again and stores the acquired PER in the memory  123 . 
     At a step  743 , the access point controller  115  judges if the PER lies within the prescribed range of the threshold values. In a case where the PER lies within the prescribed range of the threshold values, the access point controller  115  shifts to the processing of a step  744 . On the other hand, in a case where the measured PER does not lie within the prescribed range of the threshold values, the access point controller  115  returns to the processing of the step  739  and repeats the processing of the steps  739 - 742  and  743 , thereby to adjust the transmission power of the access terminal function portion  126  so that the PER may come to lie within the prescribed range of the threshold values. 
     At the step  744 , the access point controller  115  records the reported value of the transmission power of the access terminal function portion  126  in the memory  123  as a reception sensitivity value. Alternatively, the access point controller  115  may well calculate the reception sensitivity from the reported value of the transmission power of the access terminal function portion  126  and the value of the loss of the section of the access terminal function portion  126 —the receiver  134 . By way of example, the access point controller  115  reads out the reported transmission power value of the access terminal function portion  126  and the path loss value by referring to the RAM  123 , and it calculates the reception sensitivity in accordance with the following formula:
 
Reception sensitivity=(Transmission power value of Access terminal function portion)−(Path loss value)
 
     The transmission power of the access terminal function portion  126  as employed here is the transmission power whose PER has been brought into the prescribed range of the threshold values by repeating the above processing, and it is stored in the memory by way of example. Besides, the value of the path loss can be fixed to a value which can attenuate the transmission power of the access terminal function portion  126  down to a reception sensitivity point. That is, a value which is fixedly stipulated at the design of the apparatus may well be employed as the path loss value. Alternatively, the loss value (−42.3 dBm by way of example) obtained by the above calibration may well be employed. Since a manufactural dispersion is involved in the path loss value, the value of the loss can be measured at the manufacture of the apparatus so as to store the measured value in an appropriate memory. Here, the “reception sensitivity point” indicates that power value of the reception power of the access point  100  below which the reception becomes impossible. 
     Further, the access point controller  115  may well judge whether or not a receiver failure has occurred, on the basis of the reception sensitivity and in accordance with, for example, whether the reception sensitivity is greater or less than a predetermined threshold value, or whether it lies within or outside a predetermined range, so as to store a judged result in the memory. 
     At a step  745 , the access point controller  115  commands the access terminal function portion  126  to stop the packet transmission (packet transmission stop command). At a step  746 , the access terminal function portion  126  stops the packet transmission in compliance with the packet transmission stop command. At a step  747 , the access terminal function portion  126  gives the access point controller  115  “TAT-State alteration notification” which contains information indicating that the packet transmission has been stopped. 
     At a step  748 , the access point controller  115  commands the access terminal function portion  126  to release the calling connection (calling connection release command). At a step  749 , the access terminal function portion releases the calling connection in compliance with the calling connection release command. At a step  750 , the access terminal function portion  126  gives the access point controller  115  “TAT-State alteration notification” which contains information indicating that the calling connection has been released. 
     At a step  751 , the access point controller  115  commands the test function controller  127  to turn OFF the power source of the access terminal function portion  126  (power source turn-OFF command). At a step  752 , the test function controller  127  having received the power source turn-OFF command turns OFF the power source of the access terminal function portion  126 . 
     At a step  753 , the access point controller  115  commands the path switch part  132  and the function unit  113  to set the switches. At a step  754 , the switches of the path switch part  132  and test function unit  113  are set so as to pass through the paths  301  and  302  in  FIG. 3  (SW settings ( 1 )). Thus, an ordinary operation state is resumed. 
     At a step  755 , the access point controller  115  reports a test result to the maintenance terminal  103 . The test result can contain, for example, the reception sensitivity and/or the judged result based on the reception sensitivity. At a step  756 , the maintenance terminal  103  receives the test result, and it displays the received test result and/or stores the same in a storage portion, whereupon the test is ended. 
     Incidentally, the test can also be carried out as the three divided stages of the measurement path diagnosis (reception path diagnosis) in  FIG. 7 , the measurement loop calibrations (reception sensitivity correction) in  FIG. 8  and the receiver sensitivity measurement in  FIG. 9 . Alternatively, the test may well be carried out in the combination of the reception sensitivity correction and the receiver sensitivity measurement, or that of the receiver sensitivity measurement and the reception path diagnosis. Further, it may well be performed in an appropriate sequence. By way of example, in a case where the reception sensitivity has not been normally obtained in the receiver sensitivity measurement in  FIG. 9 , the reception path diagnosis in  FIG. 7  may well be performed so as to specify a failing part. 
     According to the invention, the reception sensitivity of a radio access point can be precisely measured without involving a service interruption, remotely and on-line, and without being affected by external noise. Also, it is possible to provide means for specifying a cause in a case where a desired sensitivity has not been attained. 
     The invention is applicable to, for example, industries which concern a mobile communication system or access point.