JP2012160989A - Radio quality determination apparatus, program and system for determining radio quality from allowable transmission power value - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio quality determination apparatus and the like which can determine radio quality by an allowable transmission power value in view of variation in a transmission power value based on a communication state of a mobile station when determining radio quality by the transmission power value.SOLUTION: A radio quality determination apparatus comprises transmission power value accumulation means in which a transmission power value acquired by a mobile station is accumulated in relation to existence or non-existence of user data transmission when the transmission power value is acquired, transmission power value correction means for correcting the transmission power value acquired when the user data is not transmitted by adding a predetermined offset value to the transmission power value and radio quality determination means for determining radio quality based on the corrected transmission power value.

Description

  The present invention relates to a technique for determining radio quality of a mobile station in a mobile communication network.

  In mobile communication networks, a CDMA (Code Division Multiple Access) communication system is common. The wireless communication system has a so-called “far / near problem” in which the longer the distance between the base station and the mobile station, the greater the amount of radio wave attenuation from the mobile station. In particular, this problem becomes significant with CDMA technology in which user signals from a plurality of mobile stations are mixed in the same frequency band. That is, transmission radio waves from mobile stations located near the base station interfere with transmission radio waves from other mobile stations.

Therefore, according to the CDMA technology, “transmission power control” in the mobile station is executed for the uplink (mobile station-> base station). According to transmission power control, the base station measures the radio quality of radio waves transmitted from the mobile station, and returns a transmission power control bit (TPC (Transmit Power Control) bit) corresponding to the radio quality to the mobile station. Yes (inner loop). Thereby, the mobile station controls transmission power.
・ If the radio quality of radio waves from the mobile station is poor,
Increase the transmission power of the mobile station.
・ If the radio quality of radio waves from the mobile station is excessive,
Such transmission power control for reducing the transmission power of the mobile station is controlled at high speed (for example, every 0.625 milliseconds) in consideration of the influence of fading (variation of reception intensity).

Specifically, the base station measures the following radio quality for radio waves from the mobile station.
(1) Eb / No (ratio of the received energy per bit to noise power spectral density)
Eb / No of the radio wave from the mobile station ≧ predetermined value: Control to reduce the transmission power of the mobile station Eb / No of the radio wave from the mobile station <predetermined value: Control to increase the transmission power of the mobile station (2) FER (Frame Erasure Rate)
FER of mobile station ≧ predetermined value: control to increase transmission power of mobile station FER of mobile station <predetermined value: control to decrease transmission power of mobile station

Conventionally, there is a technique for determining radio quality from a mobile station to a base station based on the transmission power value of the mobile station using such transmission power control (see, for example, Patent Document 1). According to this technique, the wireless quality is determined as follows.
High transmission power value of mobile station: Radio quality “bad”
Low transmission power value of mobile station: Radio quality “good”

Special table 2009-528803 gazette

FIG. 1 is a system configuration diagram in which a mobile station transmits user data to a base station.
FIG. 2 is a graph showing transmission power values according to the passage of time in FIG.

(S11) According to FIG. 1, the mobile station 2 is transmitting user data during the time period of 16:33 to 16:34. At this time, according to FIG. 2, the transmission power value (dBm) exceeds a predefined “radio quality determination threshold”. As described above, this is because Eb / No is low or FER is high, which means that transmission degradation occurs for user data transmitted from the mobile station 2 and the packet loss rate is high. . At this time, if the wireless quality is determined based on the transmission power value, it is determined as “bad”.

  The “radio quality determination threshold” refers to a transmission power value that should be determined as “bad” radio quality. This threshold is preferably the minimum quality that allows data to be transmitted from the mobile station to the base station.

  For example, assume that TCP (Transmission Control Protocol) equipped with a congestion control algorithm is used as a transport protocol for transmitting user data. In that case, the mobile station 2 does not transmit the next user data unless the data delivery confirmation message can be received. Therefore, it shifts to a state where user data is not transmitted.

(S12) Thereafter, according to FIG. 1, the mobile station 2 does not transmit user data during the time period of 16:35 to 16:36. At this time, according to FIG. 2, the transmission power value (dBm) does not exceed the predefined radio quality determination threshold. At this time, when the wireless quality is determined based on the transmission power value, it is determined as “good”.

(S13) When the user data is not transmitted, a wireless quality acquisition request message may be transmitted from the wireless quality determination server 1 to the mobile station 2, for example. In this case, the mobile station 2 transmits the wireless quality at that time, that is, the determination result of “good” in S12 to the wireless quality determination server 1. At this time, the mobile station 2 may transmit a history of transmission power values continuously measured in S11 to S12.

(S14) As long as the wireless quality received from the mobile station 2 is viewed, the wireless quality determination server 1 can only determine that the wireless quality is “good”. Further, even when looking at the history of the transmission power value, it can be recognized that the wireless quality is simply changed to “bad” or “good”. In addition, when the wireless quality determination server 1 determines the average transmission power value from the history, the wireless quality determination server 1 may determine that the wireless quality is “good” even though the transmission of user data has deteriorated.

  As is clear from FIG. 2, the transmission power from the mobile station varies greatly depending on whether or not user data is transmitted. That is, even in the same environment, the transmission power value differs greatly between a mobile station that is transmitting user data and a mobile station that is not transmitting user data (transmits only pilot signals and MAC channels). . If the wireless quality is determined by the technique described in Patent Document 1 using such a transmission power value, the determination is greatly mistaken.

  Therefore, according to the present invention, when the radio quality is determined based on the transmission power value, the radio quality can be determined based on the valid transmission power value in consideration of the change in the transmission power value based on the communication state of the mobile station. An object of the present invention is to provide a wireless quality determination device, a program, and a system.

According to the present invention, in a radio quality determination device for determining radio quality in a mobile station,
Transmission power value accumulating means for accumulating the transmission power value acquired by the mobile station in association with the presence or absence of transmission of user data when the transmission power value is acquired;
Transmission power value correcting means for adding a predetermined offset value to correct the transmission power value for which user data is not transmitted;
Wireless quality determination means for determining wireless quality based on the corrected transmission power value.

According to another embodiment of the wireless quality determination device of the present invention,
The transmission power value storage means stores RSSI (Received Signal Strength Indication) (reception signal strength) in association with each transmission power value,
It is also preferable to further include data transmission determination means for determining that user data is being transmitted when the transmission power value fluctuation ratio is greater than a predetermined threshold value compared to the RSSI fluctuation ratio.

  According to another embodiment of the wireless quality determination device of the present invention, the predetermined offset value is a second value when user data is transmitted with respect to a first number of transmission chips when user data is not transmitted. It is also preferable that the calculation is based on the ratio of the number of transmission chips.

According to the present invention, in a wireless quality determination program for determining wireless quality in a mobile station using a computer installed in the apparatus,
Transmission power value accumulating means for accumulating the transmission power value acquired by the mobile station in association with the presence or absence of transmission of user data when the transmission power value is acquired;
Transmission power value correcting means for adding a predetermined offset value to correct the transmission power value for which user data is not transmitted;
The computer is caused to function as a wireless quality determination unit that determines wireless quality based on the corrected transmission power value.

According to the present invention, in a system having a mobile station and a radio quality determination server connected to the mobile station via a mobile communication network,
The mobile station
A transmission power value measuring means for measuring a transmission power value at predetermined time intervals;
Data transmission detecting means for detecting the presence or absence of transmission of user data of the mobile station when the transmission power value is measured;
Transmission power value transmission means for associating the transmission power value for each predetermined time interval with the presence / absence of transmission of user data and transmitting to the wireless quality determination server,
The wireless quality judgment server
Transmission power value correcting means for adding a predetermined offset value to correct the transmission power value for which user data is not transmitted;
Wireless quality determination means for determining wireless quality based on the corrected transmission power value.

According to the present invention, in a system having a mobile station and a radio quality determination server connected to the mobile station via a mobile communication network,
The mobile station
A transmission power value measuring means for measuring a transmission power value at predetermined time intervals;
Data transmission detecting means for detecting the presence or absence of transmission of user data of the mobile station when the transmission power value is measured;
Transmission power value correcting means for adding a predetermined offset value to correct the transmission power value detected that user data is not transmitted;
Transmission power value transmitting means for transmitting the corrected transmission power value to the server,
The radio quality determination server includes radio quality determination means for determining radio quality based on a transmission power value received from a mobile station.

According to another embodiment of the system of the present invention,
The data transmission detection means
Received signal strength measuring means for measuring RSSI (received signal strength) when the transmission power value is measured;
It is also preferable to comprise data transmission determination means for determining that user data is being transmitted when the rate of variation in transmission power value is greater than a predetermined threshold value compared to the rate of variation in RSSI.

According to the present invention, in a system having a mobile station and a radio quality determination server connected to the mobile station via a mobile communication network,
The mobile station
A transmission power value measuring means for measuring a transmission power value at predetermined time intervals;
Received signal strength measuring means for measuring RSSI (received signal strength) when the transmission power value is measured;
A transmission power value transmitting means for transmitting the transmission power value and RSSI for each predetermined time interval to the server;
The wireless quality judgment server
Data transmission determination means for determining that user data is being transmitted when the transmission power value fluctuation rate is greater than a predetermined threshold value compared to the RSSI fluctuation rate;
Transmission power value correcting means for adding a predetermined offset value to correct the transmission power value detected that user data is not transmitted;
Wireless quality determination means for determining wireless quality based on the corrected transmission power value.

  According to another embodiment of the system of the present invention, the predetermined offset value is the second number of transmission chips when transmitting user data relative to the number of first transmission chips when not transmitting user data. It is also preferable that it is calculated based on the ratio of.

  According to the wireless quality determination device, program, and system of the present invention, when determining wireless quality based on a transmission power value, the wireless power is determined based on a valid transmission power value in consideration of a change in the transmission power value based on the communication state of the mobile station. Quality can be determined.

1 is a system configuration diagram in which a mobile station transmits user data to a base station. It is a graph showing the transmission power value according to the time passage in FIG. It is a functional block diagram of the radio | wireless quality determination apparatus in this invention. It is a graph showing the corrected transmission power value in this invention. It is a 1st system block diagram in this invention. It is a 2nd system block diagram in this invention. It is a 3rd system block diagram in this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 3 is a functional configuration diagram of the wireless quality judgment device according to the present invention.

  According to FIG. 3, the wireless quality determination device 1 includes a transmission power value accumulation unit 11, a data transmission determination unit 12, a transmission power value correction unit 13, a wireless quality determination unit 14, and an application unit 15. These functional components are realized by executing a program that causes a computer installed in the apparatus to function.

  The transmission power value accumulation unit 11 accumulates the transmission power value for each time acquired by the mobile station. The transmission power value is measured from the wireless communication interface in the mobile station, and may be a representative value (for example, an average value) every predetermined time (for example, every 100 milliseconds) or an instantaneous value. Good.

  Further, the transmission power value accumulation unit 11 may be associated with a flag indicating whether or not user data is transmitted for each transmission power value. This may be detected by monitoring the wireless communication interface for the mobile station. In addition, when a state in which user data is being transmitted or stopped is known in advance, the state is assigned as a flag.

  As another embodiment, the transmission power value accumulation unit 11 may be associated with a received signal strength indication (RSSI) for each transmission power value. Based on RSSI, the data transmission determination unit 12 can determine whether or not user data is transmitted.

The data transmission determination unit 12 determines the presence / absence of transmission of user data of the mobile station from the fluctuation of the RSSI using the RSSI for each transmission power value. In general, the transmission power value and RSSI have the following relationship.
-When RSSI increases, the transmission power value decreases.
-When RSSI becomes low, the transmission power value becomes high.
Using this relationship, it is determined that “if the rate of fluctuation of the transmission power value is greater than a predetermined threshold value compared to the rate of fluctuation of RSSI, user data is transmitted”. The determination result of the data transmission determination unit 12 is output to the transmission power value correction unit 13.

The transmission power value correction unit 13 adds a predetermined offset value to the transmission power value for which user data is not transmitted and corrects the transmission power value. Here, the “predetermined offset value” is calculated as follows.
Predetermined offset value (dB) = Number of transmission chips when transmitting user data /
Number of transmitted chips when user data is not transmitted

  For example, according to the uplink of CDMA2000 1xEV-DO (mobile station-> base station), the "reverse traffic channel mode" can be used. The “reverse traffic channel mode” is a channel mode used for transmitting user data and signaling information to the base station.

The reverse traffic channel mode includes transmissions on the following physical channels:
“Pilot channel / RRI (Reverse Rate Indicator) channel”:
The RRI is transmitted by being included in the pilot channel.
Every 16 slots (every 32768 chips)
“DRC channel”: configured with 1024 chips per slot (every 2048 chips) “ACK channel”: configured with 1024 chips “DATA channel”: configured with 16 slots (32768 chips (1 slot 2048 chips))

  Here, compared to the case where the mobile station is transmitting user data (RRI + DRC + DATA) and the case where user data is not transmitted (only RRI + DRC), the amount of transmission data (number of transmission chips) is 2.8 times. There is a difference. For example, when the number of transmission chips per slot is counted, the pilot channel / RRI is 2048 chips / 16 slots, that is, 128 chips / slot. The DRC channel is 1024 chips / slot and the DATA channel is 2048 chips / slot. Then, “(128 + 1024 + 2048) / (128 + 1024) = 2.8” times is calculated. Here, since it is assumed that user data is transmitted as shown in FIG. 1, the influence of the ACK channel is not included in the calculation of the offset value.

In this case, the transmission power value correction unit 13 corrects the transmission power value not transmitting user data as follows.
Corrected transmission power value [dBm] = acquired transmission power value [dBm] +4.4 [dB]
The transmission power value correction unit 13 outputs the corrected transmission power value to the radio quality determination unit 14.

  On the other hand, the transmission power value correction unit 13 outputs the transmission power value as it is to the radio quality determination unit 14 without correcting the transmission power value to which the user data is transmitted.

  FIG. 4 is a graph showing the corrected transmission power value in the present invention.

  According to FIG. 4, compared with FIG. 2, only the transmission power value in the time range in which user data is not transmitted is corrected by adding 4.4 dB. Accordingly, it can be understood that the wireless quality determination threshold is exceeded even in a time range in which user data is not transmitted. That is, even when user data is not transmitted, a result that the radio quality is “good” cannot be obtained.

  The radio quality determination unit 14 determines radio quality based on the corrected transmission power value (see, for example, FIG. 4). The wireless quality determination unit 14 is based on existing technology (see, for example, Patent Document 1). Based on the determined wireless quality, the application unit 15 can provide various services. That is, it is possible to avoid the determination that the wireless quality is “good” because the user data is simply not transmitted even though the wireless quality does not actually satisfy the predetermined quality. As a result, a monitor for the wireless quality determination server can monitor with more accurate wireless quality.

  FIG. 5 is a first system configuration diagram in the present invention.

  According to FIG. 5, the mobile station 2 includes a radio communication interface 20, a transmission power value measurement unit 21, a data transmission detection unit 22, and a transmission power value transmission unit 23. On the other hand, the wireless quality determination server 1 includes a communication interface 10, a transmission power value accumulation unit 11, a transmission power value correction unit 13, a wireless quality determination unit 14, and an application unit 15. The processing of each functional component is exactly the same as in FIG.

  According to FIG. 5, the mobile station 2 associates the transmission power value for each predetermined time interval with the presence / absence of transmission of user data and transmits it to the wireless quality determination server 1. On the other hand, the wireless quality determination server 1 corrects the transmission power value for which user data is not transmitted by adding a predetermined offset value, and determines the wireless quality based on the corrected transmission power value.

  The data transmission detection unit 22 can detect the presence / absence of transmission of user data for the wireless communication interface 20 from, for example, a baseband signal. The data transmission detection unit 22 may include an RSSI measurement unit 221 and a data transmission determination unit 222. When the transmission power value is measured, the RSSI measurement unit 221 measures RSSI (reception signal strength) from the wireless communication interface 20 and outputs the RSSI to the data transmission determination unit 222. The data transmission determination unit 222 determines that user data is being transmitted when the rate of change in transmission power value is greater than a predetermined threshold value compared to the rate of change in RSSI. The “variation” is calculated by the difference between the maximum value and the minimum value in a predetermined unit time. The presence / absence of transmission of user data as a determination result is output to the transmission power value transmission unit 23.

  FIG. 6 is a second system configuration diagram according to the present invention.

  According to FIG. 6, the mobile station 2 includes a radio communication interface 20, a transmission power value measurement unit 21, a data transmission detection unit 22, a transmission power value correction unit 24, and a transmission power value transmission unit 23. On the other hand, the wireless quality determination server 1 includes a communication interface 10, a transmission power value accumulation unit 11, a wireless quality determination unit 14, and an application unit 15. The processing of each functional component is exactly the same as in FIG.

  According to FIG. 6, compared with FIG. 5, the transmission power value correction unit exists not in the radio quality determination server 1 but in the mobile station 2. For this purpose, the mobile station 2 transmits the corrected transmission power value to the wireless quality determination server 1. On the other hand, the wireless quality determination server 1 determines the wireless quality based on the corrected transmission power value.

  Also in FIG. 6, the data transmission detection unit 22 may include an RSSI measurement unit 221 and a data transmission determination unit 222.

  FIG. 7 is a third system configuration diagram in the present invention.

  According to FIG. 7, the mobile station 2 includes a radio communication interface 20, a transmission power value measurement unit 21, an RSSI measurement unit 221, and a transmission power value transmission unit 23. On the other hand, the wireless quality determination server 1 includes a communication interface 10, a transmission power value accumulation unit 11, a data transmission determination unit 12, a transmission power value correction unit 13, a wireless quality determination unit 14, and an application unit 15. Have. The processing of each functional component is exactly the same as in FIG.

  According to FIG. 7, the mobile station 2 has the RSSI measurement unit 221 and the wireless quality determination server 1 has the data transmission determination unit 12 as compared with FIGS. 5 and 6. For this purpose, the mobile station 2 associates the transmission power value for each predetermined time interval with the RSSI and transmits it to the radio quality determination server 1. On the other hand, the wireless quality determination server 1 determines the presence / absence of transmission of user data based on RSSI, and corrects by adding a predetermined offset value to the transmission power value where the user data is not transmitted. The radio quality is determined based on the transmitted power value.

In addition, the following two are assumed as a trigger for a mobile station to transmit a transmission power value to the wireless quality determination server.
(1) The wireless quality determination server transmits a transmission power value request message to the mobile station at predetermined time intervals or at predetermined timing. On the other hand, the mobile station transmits the transmission power value to the wireless quality determination server.
(2) For example, the mobile station transmits a transmission power value to the radio quality determination server, triggered by retransmission of user data in the transport layer. However, in this case, user data is not transmitted until the TCP retransmission timer times out. Therefore, although the transmission power value in this time interval looks relatively good, a correct transmission power value can be obtained by correcting the transmission power value according to the present invention.

  As described above in detail, according to the wireless quality determination device, program, and system of the present invention, when determining the wireless quality based on the transmission power value, the change of the transmission power value based on the communication state of the mobile station is considered. Thus, the wireless quality can be determined based on the valid transmission power value.

  Note that, for example, acquisition of the transmission power value of only the pilot channel and acquisition of downlink Reverse Power Control channel information enables grasping of the radio quality status regardless of the presence / absence of data transmission and reception, and thus accurate quality measurement. Such values are generally not available. The present invention focuses on how to perform accurate quality measurement under conditions where acquirable information is limited, such as the total transmission power value normally acquired in a mobile station.

  Various changes, modifications, and omissions of the above-described various embodiments of the present invention can be easily made by those skilled in the art. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

DESCRIPTION OF SYMBOLS 1 Radio quality determination apparatus, radio quality determination server 10 Communication interface 11 Transmission power value accumulation | storage part 12 Data transmission determination part 13 Transmission power value correction | amendment part 14 Wireless quality determination part 15 Application part 2 Mobile station 20 Wireless communication interface 21 Transmission power value measurement Unit 22 data transmission detection unit 221 RSSI measurement unit 222 data transmission determination unit 23 transmission power value transmission unit 3 base station

Claims (9)

In a radio quality judgment device for judging radio quality in a mobile station,
Transmission power value storage means for storing the transmission power value acquired by the mobile station and the presence / absence of transmission of user data when the transmission power value is acquired;
Transmission power value correcting means for adding a predetermined offset value to correct the transmission power value for which user data is not transmitted;
A radio quality judgment device comprising radio quality judgment means for judging radio quality based on the corrected transmission power value. The transmission power value accumulation means accumulates RSSI (Received Signal Strength Indication) (reception signal strength) in association with each transmission power value,
The apparatus further comprises data transmission determination means for determining that user data is being transmitted when the rate of fluctuation of the transmission power value is greater than a predetermined threshold value compared to the rate of fluctuation of the RSSI. Item 2. The wireless quality determination device according to Item 1.   The predetermined offset value is calculated based on a ratio of the second number of transmission chips when transmitting the user data to the number of first transmission chips when not transmitting the user data. The radio quality determination apparatus according to claim 1, wherein the radio quality determination apparatus is provided. In a wireless quality determination program for determining wireless quality in a mobile station using a computer installed in the apparatus,
Transmission power value storage means for storing the transmission power value acquired by the mobile station and the presence / absence of transmission of user data when the transmission power value is acquired;
Transmission power value correcting means for adding a predetermined offset value to correct the transmission power value for which user data is not transmitted;
A wireless quality determination program for causing a computer to function as wireless quality determination means for determining wireless quality based on the corrected transmission power value. In a system having a mobile station and a wireless quality determination server connected to the mobile station via a mobile communication network,
The mobile station
A transmission power value measuring means for measuring a transmission power value at predetermined time intervals;
Data transmission detecting means for detecting whether or not user data of the mobile station is transmitted when the transmission power value is measured;
Transmission power value transmission means for associating the transmission power value for each predetermined time interval with the presence or absence of transmission of user data, and transmitting to the wireless quality determination server,
The wireless quality judgment server
Transmission power value correcting means for adding a predetermined offset value to correct the transmission power value for which user data is not transmitted;
And a radio quality determination unit that determines radio quality based on the corrected transmission power value. In a system having a mobile station and a wireless quality determination server connected to the mobile station via a mobile communication network,
The mobile station
A transmission power value measuring means for measuring a transmission power value at predetermined time intervals;
Data transmission detecting means for detecting whether or not user data of the mobile station is transmitted when the transmission power value is measured;
Transmission power value correcting means for correcting the transmission power value detected as not being transmitted by adding a predetermined offset value;
Transmission power value transmitting means for transmitting the corrected transmission power value to the server,
The radio quality judgment server includes radio quality judgment means for judging radio quality based on the transmission power value received from the mobile station. The data transmission detecting means is
Received signal strength measuring means for measuring RSSI (received signal strength) when the transmission power value is measured;
And a data transmission determining section for determining that user data is being transmitted when the transmission power value fluctuation ratio is greater than a predetermined threshold value compared to the RSSI fluctuation ratio. Item 7. The system according to Item 5 or 6. In a system having a mobile station and a wireless quality determination server connected to the mobile station via a mobile communication network,
The mobile station
A transmission power value measuring means for measuring a transmission power value at predetermined time intervals;
Received signal strength measuring means for measuring RSSI (received signal strength) when the transmission power value is measured;
Transmission power value transmission means for transmitting the transmission power value and the RSSI for each predetermined time interval to the server;
The wireless quality judgment server
Data transmission determination means for determining that user data is being transmitted when the transmission power value fluctuation rate is greater than a predetermined threshold value compared to the RSSI fluctuation rate;
Transmission power value correcting means for correcting the transmission power value detected as not being transmitted by adding a predetermined offset value;
And a radio quality determination unit that determines radio quality based on the corrected transmission power value.   The predetermined offset value is calculated based on a ratio of the second number of transmission chips when transmitting the user data to the number of first transmission chips when not transmitting the user data. 9. System according to any one of claims 5 to 8, characterized in that it is.

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