Source: http://www.google.com/patents/US7353020?dq=system+for+measuring+web+traffic&ei=Lg8FT__TIIr-sQKzxaGRCg
Timestamp: 2014-09-19 11:58:30
Document Index: 677845941

Matched Legal Cases: ['art 215', 'art 215', 'art 215', 'art 215', 'art 215', 'art 215', 'art 214', 'art 215', 'art 215', 'art 215', 'art 214']

Patent US7353020 - Radio access point testing apparatus and method of testing radio access point - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA 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 so as to connect the input ends of receivers to antennas or to...http://www.google.com/patents/US7353020?utm_source=gb-gplus-sharePatent US7353020 - Radio access point testing apparatus and method of testing radio access pointAdvanced Patent SearchPublication numberUS7353020 B2Publication typeGrantApplication numberUS 11/349,150Publication dateApr 1, 2008Filing dateFeb 8, 2006Priority dateNov 17, 2003Fee statusPaidAlso published asUS20060217073Publication number11349150, 349150, US 7353020 B2, US 7353020B2, US-B2-7353020, US7353020 B2, US7353020B2InventorsAkihiro Saitou, Yoshiaki Hasegawa, Masao YamayaOriginal AssigneeHitachi Communication Technologies, Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (22), Referenced by (1), Classifications (15), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetRadio access point testing apparatus and method of testing radio access pointUS 7353020 B2Abstract 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 so as 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 on the transmission power of the access terminal function portion after the adjustment.
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.
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.
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 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.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a radio access point according to an embodiment of the present invention;
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.
As an example, let'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:
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.
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 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)�).
(Access point reception power expectation)=(TAT transmission power value)−(Path loss)(TAT reception power expectation)=(Access point transmission power value)−(Path loss)
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 (S109), 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 S105), 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 S107) 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 (S111), 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 S105), 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 S107). 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 S101. 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 (S115), 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 S105), 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 S113). 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 S101. 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 S105), 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 S113), 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 (S117). 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 S117), the access point controller 115 can make the diagnosis that the path loss of the signal path 304 is excessive (S119). 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 S105 and �NO� at S113), 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 S117), and where both the access point reception power value and the TAT reception power value are judged to have lower-limit values (�YES� at S121), the access point controller 115 can make the diagnosis that the signal path 304 is disconnected (S123). 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 S105 and �NO� at S113), 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 S117), 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 S121), 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 (S125). This case is denoted as �Case-6�.
(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 receiver-0 134 is −72 dBm, and where the correction value for the frequency f2 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 receiver-0 end.
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 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:
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:
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.
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.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS5710984 *Oct 20, 1995Jan 20, 1998Sharp Microelectronics Technology, Inc.Radio transceiver with impedance matched test portUS5930707 *Sep 25, 1996Jul 27, 1999Alcatel N.V.System for remotely testing a cellphone base stationUS6094577 *Jul 2, 1998Jul 25, 2000Samsung Electronics Co., Ltd.Method for fault diagnosis of a RF receive path in a CDMA digital cellular base-station systemUS6128474 *Dec 29, 1997Oct 3, 2000Lg Information & Communications, Ltd.Test circuit of base station for mobile radio communication systemUS6131020 *Nov 18, 1997Oct 10, 2000Adc Solitra OyArrangement for measuring condition of antenna in mobile telephone systemUS6151482 *Sep 30, 1997Nov 21, 2000Telefonaktiebolaget Lm (Publ)Operation and maintenance link for antenna equipmentUS6289216 *Mar 31, 1998Sep 11, 2001Samsung Electronics Co., Ltd.Method and system for measuring standing wave ratio in a mobile communications systemUS6308065 *Dec 7, 1998Oct 23, 2001Agilent Technologies, Inc.Apparatus for testing cellular base stationsUS6310579 *May 12, 2000Oct 30, 2001Radio Frequency Systems, Inc.Method and apparatus for calibrating antenna apparatus and testing an antenna connected theretoUS6453152 *Jul 20, 1999Sep 17, 2002Samsung Electronics, Co., Ltd.Method and apparatus for measuring a base station's performance in a mobile communication systemUS6766164 *Jan 19, 1999Jul 20, 2004Lucent Technologies Inc.System and method for providing radio frequency conditions for testing wireless communications equipmentUS6812885 *May 24, 2002Nov 2, 2004Honeywell International Inc.Radio altimeter test method and apparatusUS20020119772 *Feb 25, 2002Aug 29, 2002Nec CorporationBase station testing apparatus and method for testing a base station in a CDMA communication systemUS20040152431 *Jan 21, 2004Aug 5, 2004Samsung Electronics Co., Ltd.High accuracy receiver forward and reflected path test injection circuitUS20050176375 *Feb 11, 2004Aug 11, 2005Kenneth BednaszGSM radiated sensitivity measurement techniqueUS20050202859 *Nov 24, 2004Sep 15, 2005Interdigital Technology CorporationMethod and apparatus for utilizing a directional beam antenna in a wireless transmit/receive unitUS20060274657 *Jun 1, 2005Dec 7, 2006Christian OlgaardMethod for measuring sensitivity of data packet signal receiverJP2000332674A Title not availableJP2002271280A Title not availableJP2005151189A Title not availableJPH0514291A Title not availableJPH11154903A Title not available* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS7848745Feb 16, 2010Dec 7, 2010Hitachi, Ltd.Radio access point testing method and testing apparatusClassifications U.S. Classification455/424, 455/115.1, 455/67.11, 455/423, 455/561International ClassificationH04W52/20, H04W52/24Cooperative ClassificationH04W52/20, H04W52/242, H04B17/0062, H04W52/245, H04W52/24European ClassificationH04B17/00B2, H04W52/24, H04W52/20Legal EventsDateCodeEventDescriptionAug 31, 2011FPAYFee paymentYear of fee payment: 4Jan 7, 2010ASAssignmentOwner name: HITACHI, LTD.,JAPANFree format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100211;REEL/FRAME:23741/708Effective date: 20090701Owner name: HITACHI, LTD.,JAPANFree format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100218;REEL/FRAME:23741/708Effective date: 20090701Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100304;REEL/FRAME:23741/708Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100309;REEL/FRAME:23741/708Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100311;REEL/FRAME:23741/708Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100318;REEL/FRAME:23741/708Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100329;REEL/FRAME:23741/708Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100408;REEL/FRAME:23741/708Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100511;REEL/FRAME:23741/708Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;US-ASSIGNMENT DATABASE UPDATED:20100525;REEL/FRAME:23741/708Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;REEL/FRAME:23741/708Free format text: MERGER;ASSIGNOR:HITACHI COMMUNICATION TECHNOLOGIES, LTD.;REEL/FRAME:023741/0708Owner name: HITACHI, LTD., JAPANRotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google