JP6992366B2 - Base station equipment, transmission method, program - Google Patents

Description

The present invention relates to communication technology, and more particularly to a base station device for transmitting data, a transmission method, and a program.

All base station devices in mobile communication systems may operate at a common frequency. When a packet signal transmitted from one terminal device is received by a plurality of base station devices, the control station connected to the upper level of each base station device is of quality among the packet signals sent from the plurality of base station devices. A packet with a high signal is selected and transmitted to the network (for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2002-335582

In such a process, a process based on a preliminary measurement result between the base station devices is executed. However, in the prior art, the delay of the network between the base station apparatus and the control station is not considered. For example, when a base station device is connected to an IP (Internet Protocol) network, a delay that is difficult to predict and measure in real time and quantitatively occurs in the IP network. Even if the quality of the packet signal sent from a certain base station device is good, if a large network delay occurs, the data may be delayed in reaching the control station and may not be selected by the control station. In such a case, the control station may not be able to select the packet of the best quality, and the communication quality may be deteriorated. Even when such a delay that is difficult to predict and measure in real time and quantitatively occurs, it is required to suppress the influence of the delay.

The present invention has been made in view of these circumstances, and an object of the present invention is to provide a technique for reducing the influence of delay on communication quality even when an unexpected delay occurs.

In order to solve the above problems, the base station apparatus of a certain aspect of the present invention includes a first acquisition unit that acquires first data from a terminal device, a second acquisition unit that acquires second data from a control device, and a second acquisition unit. Based on the comparison result of the judgment unit that compares the quality of the first data acquired by the 1 acquisition unit and the quality of the second data acquired by the second acquisition unit, and the comparison result of the determination unit, the first data and the second data Among them, a transmission unit for transmitting at least a part of the higher quality is provided. The second acquisition unit acquires, as the second data, the data selected as the highest quality data by the control device from the plurality of data received from the terminal devices by each of the plurality of base station devices .
Another aspect of the invention is also a base station device. This device includes a first acquisition unit that acquires the first data from the terminal device, a second acquisition unit that acquires the second data from the control device, the quality of the first data acquired by the first acquisition unit, and a second. Transmission that transmits at least a part of the first data and the second data, whichever has the higher quality, based on the comparison result between the judgment unit that compares the quality of the second data acquired by the acquisition unit and the judgment unit. It is equipped with a department. The first acquisition unit acquires a plurality of first data, and each of the plurality of first data includes time information indicating the time received from the terminal device, and the second acquisition unit acquires the second data. The data includes time information, and the determination unit determines the quality of the first data and the second when the difference between the time information contained in the first data and the time information contained in the second data satisfies a predetermined condition. Compare with the quality of the data.
Yet another aspect of the invention is also a base station device. This device includes a first acquisition unit that acquires the first data from the terminal device, a second acquisition unit that acquires the second data from the control device, the quality of the first data acquired by the first acquisition unit, and a second. Transmission that transmits at least a part of the first data and the second data, whichever has the higher quality, based on the comparison result between the judgment unit that compares the quality of the second data acquired by the acquisition unit and the judgment unit. It is equipped with a department. The transmission unit makes the transmission power when transmitting the first data smaller than the transmission power when transmitting the second data.

Another aspect of the present invention is a transmission method. In this method, the first acquisition step of acquiring the first data from the terminal device, the second acquisition step of acquiring the second data from the control device, the quality of the acquired first data, and the quality of the acquired second data. It includes a comparison step for comparing with and a transmission step for transmitting at least a part of the first data and the second data having higher quality based on the comparison result . In the second acquisition step, the data selected as the highest quality data by the control device from the plurality of data received from the terminal devices by each of the plurality of base station devices is acquired as the second data .
Another aspect of the invention is also a transmission method. In this method, the first acquisition step of acquiring the first data from the terminal device, the second acquisition step of acquiring the second data from the control device, the quality of the acquired first data, and the quality of the acquired second data. It includes a comparison step for comparing with and a transmission step for transmitting at least a part of the first data and the second data having higher quality based on the comparison result. In the first acquisition step, a plurality of first data are acquired, and each of the plurality of first data includes time information indicating the time received from the terminal device, and the second acquisition step is acquired. The data includes time information, and the comparison step is the quality of the first data and the second, when the difference between the time information contained in the first data and the time information contained in the second data satisfies a predetermined condition. Compare with the quality of the data .

It should be noted that any combination of the above components and the conversion of the expression of the present invention between methods, devices, systems, recording media, computer programs and the like are also effective as aspects of the present invention.

According to the present invention, even if an unexpected delay occurs, the influence of the delay on the communication quality can be reduced.

It is a figure which shows the structure of the communication system which concerns on Example. It is a figure which shows the outline of the processing by the communication system of FIG. It is a figure which shows the outline of the transmission processing by the communication system of FIG. It is a figure which shows the outline of the processing which is assumed when the delay of the IP network occurs in the communication system of FIG. It is a figure which shows the structure of the base station apparatus of FIG. It is a figure which shows the data structure of the data stored in the 1st acquisition part of FIG. It is a figure which shows the data structure of the packet signal transmitted from the communication part of FIG. It is a figure which shows the structure of the control device of FIG. It is a figure which shows the data structure of the data stored in the packet signal buffer part of FIG. It is a figure which shows the data structure of the packet signal transmitted from the communication part of FIG. It is a figure which shows the data structure of the data stored in the 2nd acquisition part of FIG. It is a flowchart which shows the transmission process by the base station apparatus of FIG. It is a figure which shows the arrangement of the communication area in the communication system of FIG. It is a figure which shows the data structure of the transmission power setting table stored in the determination part of FIG. It is a figure which shows the arrangement of the communication area in the case of FIG. It is a figure which shows the data structure of another transmission power setting table stored in the base station apparatus information control apparatus which concerns on embodiment.

Before explaining the present invention in detail, first, an outline will be given. An embodiment of the present invention relates to a communication system including a plurality of terminal devices that communicate with each other via a base station device. This communication system corresponds to, for example, a commercial wireless system. Further, the frequency of the uplink from the terminal device to the base station device (hereinafter referred to as “upstream frequency”) and the frequency of the downlink from the base station device to the terminal device (hereinafter referred to as “downstream frequency”) are different. The uplink frequency corresponds to the reception frequency in the base station apparatus, and the downlink frequency corresponds to the transmission frequency in the base station apparatus. On the other hand, the uplink frequency of each of the plurality of base station devices is the same, and the downlink frequency of each of the plurality of base station devices is also the same. In the following, the combination of one uplink frequency and one downlink frequency may be referred to as a "channel", but one of the uplink frequency and the downlink frequency may be referred to as a "channel". A plurality of base station devices are connected to a control device, and the control device controls each base station device and when the base station device receives call information (transmission information) from a terminal device, a plurality of base station devices are connected. Transfer the received call information to the base station device. This corresponds to the execution of simulcast communication across a plurality of base station devices.

One terminal device transmits call information including voice information. Each of the plurality of base station devices that have received the call information generates a packet signal by converting the call information into an IP packet, and transmits the packet signal to the control device via the IP network. At that time, the base station apparatus also stores information regarding the quality of the received call information (hereinafter referred to as “quality information”) in the packet signal. The control device compares the quality information in the packet signal received from each of the plurality of base station devices, and selects the call information of the packet signal containing the highest quality information. The control device generates a packet signal including information on the time when each of the plurality of base station devices should transmit the selected call information (hereinafter referred to as “transmission time”) and the call information. The control device transmits a packet signal to a plurality of base station devices via an IP network. When the plurality of base station devices receive the packet signal, they transmit the call information when the transmission time included in the packet signal arrives. The plurality of terminal devices receive the call information and reproduce the voice. Such processing is periodically repeated as long as the utterance of the user using one terminal device continues.

When a delay occurs in one of the routes from each of the plurality of base station devices to the control device, the reception of the packet signal from one base station device is not in time for the selection of the calling information in the control device. There is also. At that time, the control device selects the calling information contained in one of the remaining packet signals and executes the above-mentioned processing. When the one base station device receives the packet signal from the control device, it transmits the call information contained in the packet signal, but the received call is more important than the quality of the call information contained in the packet signal. The quality of the information may be higher. That is, there occurs a situation in which the quality of the received call information is lower than the quality of the received call information.

In this embodiment, the base station device provides the highest quality call information to the extent possible in case the packet signal from one base station device is not normally received by the control device due to the delay of the IP network. Means that enable transmission are provided. Each base station device stores call information contained in a packet signal to be transmitted to the control device in a buffer. Further, each base station device compares the quality of the stored call information with the quality of the call information contained in the packet signal from the control device, and if the former is higher than the latter, the stored call is stored. Send information.

FIG. 1 shows the configuration of the communication system 100. The communication system 100 is a first base station device 14a, a second base station device 14b, a third base station device 14c, and a terminal device 16 collectively referred to as an IP network 10, a control device 12, and a base station device 14. 1 terminal device 16a, 2nd terminal device 16b, 3rd terminal device 16c, 1st synchronous control reference device 20a collectively referred to as synchronous control reference device 20, 2nd synchronous control reference device 20b, 3rd synchronous control The reference device 20c and the fourth synchronization control reference device 20d are included. Here, the number of base station devices 14 included in the communication system 100 is not limited to "3", and the number of terminal devices 16 is not limited to "3" and may be more or less than them. May be good.

As described above, the plurality of terminal devices 16 and the plurality of base station devices 14 are compatible with commercial wireless systems, and each terminal device 16 executes voice communication via one or more base station devices 14. do. Each terminal device 16 is provided with a PTT (Push To Talk) button, and the terminal device 16 with the PTT button pressed down transmits the user's voice to the base station device 14 as call information. When the plurality of base station devices 14 receive the call information from the terminal device 16, they generate a packet signal including the call information and transmit the packet signal to the control device 12 via the IP network 10. At that time, the plurality of base station devices 14 measure the reception sensitivity (RSSI: Received Signal Strength Indicator), the error rate of the call information, etc. as the quality of the call information, and the quality information as the measurement result is also used as the packet signal. include.

The control device 12 receives the packet signals from the plurality of base station devices 14, and selects the call information of the packet signal including the highest quality information based on the quality information included in each packet signal. Further, the control device 12 generates a transmission time for the selected call information, and transmits a packet signal including the transmission time and the call information to the plurality of base station devices 14 via the IP network 10. .. Here, the fourth synchronization control reference device 20d is connected to the control device 12, and the fourth synchronization control reference device 20d is, for example, a high-precision NTP (Network Time Protocol) server, GPS (Global Positioning System). ) It is a receiving device. The fourth synchronous control reference device 20d generates a reference time (hereinafter referred to as “reference time”), and the control device 12 generates a transmission time based on the reference time.

Upon receiving the packet signal, the plurality of base station devices 14 extract the transmission time and the call information from the packet signal. A synchronization control reference device 20 is also connected to each base station device 14, and the base station device 14 transmits call information when the reference time acquired from the synchronization control reference device 20 has passed the transmission time. do. Here, since the first synchronous control reference device 20a to the fourth synchronous control reference device 20d are synchronized, the first base station device 14a to the third base station device 14c transmit call information at the same timing. Send with. Therefore, it can be said that the communication system 100 is a simulcast system. The terminal device 16 receives the call information from the base station device 14.

FIG. 2 shows an outline of processing by the communication system 100. Call information was received from the packet signal transmitted from the first base station device 14a to the control device 12 from the third base station device 14c via the IP network 10, and the base station device 14 received the call information from the terminal device 16. The call reception time is included. The control device 12 stores the packet signal received from each base station device 14 in a buffer, and the same call information is sent to each of the packet signals in which the call reception time in the packet signal is included in a fixed period of several millisec. Considered to be included. The control device 12 selects the highest quality call information from the plurality of call information considered to be the same call information.

The control device 12 generates a packet signal including the selected call information and the transmission time, and transmits the packet signal from the first base station device 14a to the third base station device 14c via the IP network 10. Since this transmission time is set for the purpose of matching the transmission timings in all the base station devices 14, the same value is set for all the base station devices 14. Further, the transmission time is a value considering the delay time of the IP network 10.

FIG. 3 shows an outline of transmission processing by the communication system 100. The control device 12 transmits the packet signal N + 5 from the packet signal N to the base station device 14 at regular intervals. After storing in each buffer, the base station apparatus 14 extracts the transmission time included in the packet signal, and when the reference time obtained from the synchronization control reference apparatus 20 arrives at the transmission time, the call information is transmitted. Send. Therefore, the call information N + 5 is transmitted from the call information N included in each of the packet signals N + 5 from the packet signal N at regular intervals.

FIG. 4 shows an outline of processing assumed when an IP network delay occurs in the communication system 100. As mentioned above, in the IP network 10, unexpected network delay may occur due to its nature. This network delay depends on the installation status of the line (best effort / guarantee, etc.) and the usage status of traffic, and it is extremely difficult to predict it quantitatively. Therefore, if an unexpected network delay occurs after each base station device 14 transmits a packet signal to the control device 12, the control device 12 cannot normally receive the packet signal. The packet signal transmitted from the third base station device 14c is in a state of not arriving at the control device 12 within a certain period due to the network delay. Therefore, the quality evaluation of the call information in the control device 12 is targeted only for the packet signals from the first base station device 14a and the second base station device 14b.

Here, it is assumed that the quality of the call information received by each base station device 14 from the terminal device 16 is the highest in the third base station device 14c and the lowest in the first base station device 14a. However, since the call information from the third base station device 14c is not subject to evaluation, each base station device 14 has the highest quality of the call information from the third base station device 14c. 2 Call information from the base station device 14b is distributed. As a result, each base station device 14 transmits call information that is not of the highest quality.

This embodiment for dealing with this will be described, but here, according to the time series of processing, (1) reception processing by the base station device 14, (2) selection processing by the control device 12, and (3) base. The transmission process in the station apparatus 14 will be described in this order.

(1) Reception processing in the base station device 14 FIG. 5 shows the configuration of the base station device 14. The base station device 14 includes a radio reception unit 30, a first acquisition unit 32, a determination unit 34, a communication unit 36, a second acquisition unit 38, a detection unit 40, a control unit 42, and a radio transmission unit 44. The detection unit 40 is connected to the synchronization control reference device 20 of FIG. 1, and sequentially acquires the reference time from the synchronization control reference device 20. The wireless receiving unit 30 receives a signal from the terminal device 16 by executing a receiving process corresponding to the commercial wireless system. Here, when the wireless reception unit 30 receives the call information from one terminal device 16, the wireless reception unit 30 acquires the reference time as the call reception time from the detection unit 40. Call information includes voice information. Further, the wireless reception unit 30 generates a packet signal so as to include the call reception time and the call information. Here, the packet signal is generated in units of 100 milliseconds, for example. The wireless receiving unit 30 outputs the packet signal to the first acquisition unit 32.

The determination unit 34 determines the quality of the call information included in the packet signal received by the first acquisition unit 32. As described above, RSSI, error rate, etc. are used as indicators of the quality of call information. The determination unit 34 outputs the measurement result as quality information to the first acquisition unit 32. The first acquisition unit 32 acquires the packet signal from the wireless reception unit 30, and also acquires the quality information of the call information included in the packet signal from the determination unit 34. The first acquisition unit 32 stores the packet signal after including the quality information in the packet signal. Therefore, the first acquisition unit 32 can be said to be a transmission packet signal buffer unit.

FIG. 6 shows a data structure of data stored in the first acquisition unit 32. The call reception time indicates the time information when the call information from the terminal device 16 is received, and the call information and the quality information from the terminal device 16 are recorded in the data area. The first acquisition unit 32 can store a fixed number of packet signals (5 as an example), and when a new packet signal is added while the number of buffers has reached the upper limit, the packet signal having the oldest call reception time is used first. Delete in order. Here, when a packet signal having a call reception time of "10:10:32:502" is newly added, the call reception time is "10:10:32:002". The packet signal of 01 is deleted. Return to FIG.

The first acquisition unit 32 outputs the added packet signal to the communication unit 36. The communication unit 36 receives the packet signal from the first acquisition unit 32. The communication unit 36 is connected to the IP network 10 of FIG. 1 and transmits a packet signal to the control device 12 via the IP network 10. It can be said that the communication unit 36 that executes such a transmission process is a transmission unit. FIG. 7 shows the data structure of the packet signal transmitted from the communication unit 36. As shown in the figure, call reception time, call information, and quality information are included. The description of the other components in FIG. 5 will be described later.

(2) Selection process in the control device 12 FIG. 8 shows the configuration of the control device 12. The control device 12 includes a communication unit 50, a packet signal buffer unit 52, a determination unit 54, a detection unit 56, and a packet signal distribution unit 58. The communication unit 50 is connected to an IP network 10 (not shown), and receives a packet signal from each base station device 14 via the IP network 10. The communication unit 50 outputs the packet signal to the packet signal buffer unit 52.

The detection unit 56 is connected to the synchronization control reference device 20 of FIG. 1, and sequentially acquires the reference time from the synchronization control reference device 20. The packet signal buffer unit 52 receives the packet signal from the communication unit 50 and also receives the reference time for receiving the packet signal from the detection unit 56. The packet signal buffer unit 52 stores the packet signal received from the communication unit 50. FIG. 9 shows a data structure of data stored in the packet signal buffer unit 52. The name of the base station device 14 that transmitted the packet signal is stored in the source base station device name, the time when the control device 12 receives the packet signal is shown in the packet signal reception time, and the call reception time and the data area. The contents of the packet signal are recorded as they are. Return to FIG.

The packet signal distribution unit 58 refers to the call reception time in the packet signal stored in the packet signal buffer unit 52, and is a packet signal of call information that is not the same as the previously received call information (new call information). Packet signal). When the time difference between the call reception time of the newly received packet signal and the call reception time of the packet signal received in the past is equal to or less than a predetermined value, it is determined as new call information. For example, this predetermined value is 5 milliseconds. In the case of FIG. 9, No. The call reception time of the packet signal of 03 is "10:10:32:002", and No. The call reception time of the packet signal of 04 is "10:10:32:102". Since these have an interval of 100 milliseconds, No. Calling information of 03 and No. It is determined that the call information of 04 is not the same. At that time, the packet signal distribution unit 58 is No. The timer T is operated starting from the reception time of the packet signal of the packet signal of 04. That is, when it is determined that the packet signal is new call information, the packet signal distribution unit 58 operates the timer T with the reception time of the packet signal as the starting point. The end time of the timer T is set by the line speed of the IP network 10 or the like, and in this embodiment, it is set to, for example, 50 milliseconds.

At the end of the timer T, in the case of FIG. 9, No. The packet signal from the second base station apparatus 14b of 05 and No. The packet signal from the third base station device 14c of 06 is received. No. 05 and No. The call reception time of the packet signal of 06 is "10:10:32:102" and "10:10:32:103", respectively, and the time difference from the reception time of the packet signal operated by the timer T is equal to or less than a predetermined value. be. Therefore, No. It is determined that the call content is the same as the call information of 04. The packet signal distribution unit 58 tells the determination unit 54 that No. 04, No. 05, No. Instructs the comparison of the quality information of the packet signal of 06. The determination unit 54 is No. 04, No. 05, No. The highest quality packet signal is identified from the quality information of 06, and the packet signal distribution unit 58 is notified.

The packet signal distribution unit 58 generates a packet signal based on the packet signal notified from the determination unit 54 and the transmission time. FIG. 10 shows a data structure of a packet signal transmitted from the communication unit 50. As shown in the figure, transmission time, call reception time, call information, and quality information are included. Although not shown in FIG. 10, the packet signal transmitted from the communication unit 50 may include information about the source base station device (information indicating the base station device 14 that has received the packet signal). Return to FIG. The transmission time is set according to the line speed of the IP network 10 and the like. For example, the time 100 milliseconds after the earliest call reception time is set. In addition, the packet signal No. with which the quality information was compared. 04, No. 05, No. 06 may be deleted from the packet signal buffer unit 52 after a certain period of time.

The quality is determined by the determination unit 54, for example, as follows.
(A) The first method is a method using RSSI. In this case, the quality information indicates the RSSI value when the radio receiving unit 30 in the base station apparatus 14 receives the call information. The determination unit 54 selects the quality information having the largest RSSI value among the quality information to be compared.
(B) The second method is a method using information about an error. In this case, the quality information is corrected by a numerical value indicating the number of errors (number of errors, error rate, etc.) that occurred in the wireless communication when the wireless receiving unit 30 received the call information, or by error correction processing. A numerical value indicating the number of errors (number of errors, error rate, etc.) is shown. The determination unit 54 selects the quality information to be compared, which has the smallest numerical value indicating the degree of error.

(C) The third method is a method using call information. The determination unit 54 analyzes the call information of each packet signal and detects noise components other than voice. For example, a frequency component other than the band peculiar to voice or a component having a temporal amplitude change of a predetermined value or more may be used as a noise component. Then, among the call information to be compared, the one having the smallest noise component is selected. The determination unit 54 may calculate both the voice component and the noise component, calculate the SN ratio which is the ratio between them, and select the call information having the largest SN ratio. When this third method is used, the quality information of each packet signal can be omitted.

Further, the quality may be determined by combining the first method to the third method. For example, the overall score S is calculated by the calculation shown in the equation (1), where R is the RSSI value, E is the numerical value indicating the degree of error, and N is the numerical value indicating the noise component. Here, α, β, and γ are weighting coefficients, and α> 0, β <0, and γ <0. Then, the packet signal having the highest total score S is selected.
S = αR + βE + γN equation (1)
The packet signal distribution unit 58 outputs the generated packet signal to the communication unit 50. The communication unit 50 transmits a packet signal from the first base station device 14a to the third base station device 14c via the IP network 10.

(3) Transmission processing in the base station device 14 When the communication unit 36 of the base station device 14 shown in FIG. 5 receives the packet signal from the control device 12 via the IP network 10, the communication unit 36 acquires the packet signal second. Output to unit 38. The communication unit 36 that executes such reception processing can be said to be a reception unit. Further, the reception process is performed even when the transmission process is not performed.

The second acquisition unit 38 acquires the packet signal from the communication unit 36. The second acquisition unit 38 stores the packet signal. Therefore, the second acquisition unit 38 can be said to be a received packet signal buffer unit. The second acquisition unit 38 receives the reference time from the detection unit 40, and does not store the packet signal when the transmission time in the packet signal has passed the reference time. FIG. 11 shows a data structure of data stored in the second acquisition unit 38. As shown in the figure, a transmission time, a call reception time, and a data area are included, and the data area includes call information and quality information. Such a second acquisition unit 38 is selected by the control device 12 as the highest quality data from the plurality of call information received by each of the plurality of base station devices 14 from the terminal device 16. It can be said to acquire information. Return to FIG.

Here, FIG. 12 is used to explain the processing of the determination unit 34 and the control unit 42. FIG. 12 is a flowchart showing a transmission process by the base station apparatus 14. The control unit 42 acquires the reference time from the detection unit 40 (S100). The control unit 42 monitors the transmission time in the packet signal in the second acquisition unit 38, and determines whether or not there is a packet signal whose reference time has passed the transmission time (S110). If there is no packet signal whose reference time has passed the transmission time (N in S110), the process returns to S100. Before returning to S100, the processing may be stopped (sleep) for a predetermined time. If there is a packet signal whose reference time has passed the transmission time (Y in S110), the process proceeds to S120.

The control unit 42 acquires the call reception time in the packet signal (scheduled transmission packet signal) determined by S110 that the reference time has passed the transmission time (S120). Next, the control unit 42 targets the packet signal in the first acquisition unit 32, and the call reception time is included in the range of the call reception time acquired in S120 and a certain period (for example, several millisec). It is determined whether or not the packet signal is present (S130). When the packet signal included in the fixed period does not exist (N in S130), the control unit 42 transmits the call information included in the packet signal in the second acquisition unit 38 (S200). After that, the control unit 42 deletes the packet signal including the call information transmitted from the second acquisition unit 38 (S300).

When the packet signal included in the fixed period exists (Y in S130), the following processing is performed. The packet signal in the first acquisition unit 32 included in a certain period is hereinafter referred to as a “directly received packet signal”. The control unit 42 notifies the determination unit 34 of the packet signal to be transmitted and the directly received packet signal. The call information or the quality information itself of the two packet signals may be notified, or the address of the buffer storing these information may be notified.

The determination unit 34 evaluates the quality of the call information included in the packet signal to be transmitted (S140). The determination unit 34 evaluates the quality of the call information included in the directly received packet signal (S150). The determination unit 34 determines which of the scheduled transmission packet signal and the directly received packet signal has the better quality of the call information (S160). That is, the determination unit 34 compares the quality of the call information included in the directly received packet signal with the quality of the call information included in the scheduled transmission packet signal. It should be noted that such a comparison is performed when the difference between the time information included in the directly received packet signal and the time information included in the scheduled transmission packet signal satisfies a predetermined condition. Further, for the comparison, at least one of the RSSI, the degree of error, and the noise included in the voice data is used as in the determination unit 54 of the control device 12.

When it is determined that the quality of the directly received packet signal is high (Y in S160), the control unit 42 transmits the call information included in the packet signal in the first acquisition unit 32 (S210). When it is determined that the quality of the directly received packet signal is not high (N of S160), the control unit 42 transmits the call information included in the packet signal in the second acquisition unit 38 (S200). After that, the control unit 42 deletes the packet signal including the call information transmitted from the second acquisition unit 38 (S300).

Although not shown in FIG. 12, the "source base station device name" received the packet signal after including the "source base station device name" in the packet signal delivered from the control device 12. If it matches the "base station device name" of the base station device (the base station device), the process of searching in the first acquisition unit 32 (S130) is omitted, and the packet signal in the second acquisition unit 38 is transmitted. It may be (S200). Return to FIG.

By executing the transmission process corresponding to the commercial wireless system, the wireless transmission unit 44 stores the call information included in the packet signal stored in the first acquisition unit 32 or the second acquisition unit 38. The call information included in the packet signal is transmitted to the terminal device 16. That is, the wireless transmission unit 44 has the quality of the call information contained in the packet signal stored in the first acquisition unit 32 or the call information contained in the packet signal stored in the second acquisition unit 38. Sends the higher one. When the terminal device 16 has a monitoring function of a wireless communication system or the like, the wireless transmission unit 44 may transmit the entire packet signal including the quality data.

Here, the effect of such a configuration will be specifically described. It is assumed that FIGS. 6 and 11 are data stored in the first acquisition unit 32 and the second acquisition unit 38 of the third base station device 14c, respectively. In the packet signal buffer unit 52 in the control device 12 of FIG. 9, as shown in FIG. 9, the same call information is No. At 07, the first base station apparatus 14a, No. At 08, the packet signal from the second base station device 14b is received. On the other hand, the third base station apparatus 14c has the same call information as No. 6 in FIG. Although the data of 03 is received, the data is in a state where the packet signal from the third base station device 14c has not reached the control device 12 at a normal time due to the delay of the IP network 10. Further, the quality of the call information received from the terminal device 16 is "3rd base station device 14c (high quality)> 2nd base station device 14b (medium quality)> 1st base station device 14a (low quality)". Imagine if there was one.

In that case, since the packet signal of the third base station device 14c is not subject to the quality comparison process in the control device 12, the packet signal of the second base station device 14b (medium quality) is delivered to each base station device 14. .. According to the prior art, each base station apparatus 14 transmits medium-quality call information received by the second base station apparatus 14b, but according to the present embodiment, the third base station apparatus 14c owns the first acquisition. The high-quality call information held in the unit 32 is transmitted. As a result, even if a delay occurs in the IP network 10 and the packet signal cannot be normally transmitted from the base station device 14 to the control device 12, each base station device 14 can transmit higher quality call information to the extent possible.

When each base station device 14 switches the call information to be transmitted by determining the quality of the call information, one base station device 14 transmits the call information from the control device 12, and another base station device 14 transmits the call information. 14 may transmit its own call information. This corresponds to transmission of call information different from each other from the plurality of base station devices 14. FIG. 13 shows the arrangement of the communication area 18 in the communication system 100. Each base station device 14 forms a communication area 18 as a communicable area. Specifically, the first base station apparatus 14a forms the first communication area 18a, the second base station apparatus 14b forms the second communication area 18b, and the third base station apparatus 14c forms the third communication area 18c. To form. Further, since the same channel is used in the first base station apparatus 14a to the third base station apparatus 14c, the same channel is used in the first communication area 18a to the third communication area 18c.

Interference may occur if different calling information is transmitted in the overlapping communication areas 18. Here, it is assumed that the first base station device 14a and the second base station device 14b transmit the call information from the control device 12, and the third base station device 14c transmits its own call information. In that case, interference occurs in the portion where the first communication area 18a and the third communication area 18c overlap and the portion where the second communication area 18b and the third communication area 18c overlap.

In order to deal with this, when the call information is transmitted depending on whether the call information from the control device 12 is transmitted or the call information held in the base station device 14 is transmitted. The transmission power may be switched. FIG. 14 shows the data structure of the transmission power setting table stored in the control unit 42. In the transmission power setting table, the transmission power for each call information source (control device 12 or base station device 14) is set. When the call information source is the control device 12, a value for forming the normal communication area 18 is set for the transmission power. On the other hand, when the calling information source is the base station device 14, a value is set for the transmission power so that the adjacent base station device and the communication area 18 do not overlap. For example, when transmitting the call information from the control device 12, the transmission power is set to 50 W, and when transmitting the call information held by the base station device 14, the transmission power is set to 30 W. .. That is, the wireless transmission unit 44 reduces the transmission power when transmitting the call information held by the base station device 14 as compared with the case where the call information from the control device 12 is transmitted.

FIG. 15 shows the arrangement of the communication area 18 in the case of FIG. This is shown in the same manner as in FIG. The third communication area 18c is narrower than the first communication area 18a and the second communication area 18b. As a result, the third communication area 18c does not overlap with the first communication area 18a and the second communication area 18b. As a result, interference between the first communication area 18a and the third communication area 18c and between the second communication area 18b and the third communication area 18c is less likely to occur.

The transmission power setting table may be stored not in the base station device 14 but in the base station device information control device (not shown) connected to the IP network 10. The base station device information control device centrally manages the overlapping state of the communication area 18 of each base station device 14 and the transmission power when each base station device 14 transmits call information.

FIG. 16 shows a data structure of another transmission power setting table stored in the base station device information control device. The name of each base station device 14 is shown in the base station device name, the call information source type of the control device 12 or the base station device 14 is shown as the call information source, and the control device 12 or the base station is shown as the transmission power. The transmission power value of the device 14 is shown. The transmission power setting table is updated when the operator of the communication system 100 installs the base station device 14, or when the installation location of the installed base station device 14 is changed. Each base station device 14 acquires a transmission power value from the base station device information control device at an arbitrary timing, and switches the transmission power when transmitting the call information for each call information. Further, the base station device information control device may be included in the control device 12.

The control device 12 and the base station device 14 described above can be realized by the CPU, memory, or other LSI of an arbitrary computer in terms of hardware, and can be realized by a program loaded in memory in terms of software. , Here, the functional blocks realized by their cooperation are drawn. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms only by hardware and by a combination of hardware and software.

According to this embodiment, the higher quality call information is transmitted based on the comparison result between the quality of the call information from the terminal device and the quality of the call information from the control device. When the quality of the call information from the terminal device is higher than the quality of the call information from the device, the call information from the terminal device can be transmitted. Further, even when the control device receives the highest quality call information from the plurality of call information received by each of the plurality of base station devices, the terminal has a higher quality than the call information. Call information from the device can be transmitted. Further, since the call information from the terminal device is transmitted to the control device, the call information from the terminal device can be compared with the call information from another base station device in the control device.

In addition, since the higher quality call information is transmitted based on the comparison result between the quality of the call information from the terminal device and the quality of the call information from the control device, the route to the control device Even if an unexpected delay or failure occurs, the effect of the delay or failure on the communication quality can be reduced. In addition, even if the packet signal cannot be normally transmitted from the base station device to the control device due to the delay of the IP network, the base station device holds a certain number of packet signals, so that higher quality call information can be transmitted. .. In addition, even if a network delay occurs between the base station device and the control device, the highest quality call information can be transmitted.

Further, when the difference between the time information for the call information from the terminal device and the time information for the call information from the control device satisfies a predetermined condition, the qualities of these are compared, so that the contents of the same voice information are the same. You can compare the quality of the call information that includes. Also, since at least one of RSSI, error degree, and noise is compared, quality can be compared accurately. Further, since the transmission power when transmitting the call information from the terminal device is smaller than the transmission power when transmitting the call information from the control device, the influence of interference can be reduced.

The present invention has been described above based on the examples. This embodiment is an example, and it is understood by those skilled in the art that various modifications are possible for each of these components and combinations of each processing process, and that such modifications are also within the scope of the present invention. ..

According to this embodiment, the communication system 100 uses a commercial wireless system. However, the present invention is not limited to this, and for example, a wireless communication system such as a mobile phone other than a commercial wireless system may be used. According to this modification, the degree of freedom of the system can be improved.

According to this embodiment, the control device 12 is configured separately from the base station device 14, and is connected to the base station device 14 via the IP network 10. However, the present invention is not limited to this, and for example, the control device 12 may be integrally configured by being included in any of the base station devices 14. According to this modification, the degree of freedom of configuration can be improved.

According to this embodiment, the transmission time is used as a parameter instructing the transmission timing of the call information from the control device 12. However, the present invention is not limited to this, and for example, a counter value derived based on a PPS (Pulse Pulse second) signal obtained from the synchronization control reference device 20 may be used. According to this modification, the degree of freedom of configuration can be improved.

In this embodiment, the IP network 10 will be described as an example. However, the present invention is not limited to this, and for example, another network may be used in which the transmission delay time of the network varies. According to this modification, the degree of freedom of configuration can be improved.

10 IP network, 12 control device, 14 base station device, 16 terminal device, 18 communication area, 20 synchronous control reference device, 30 wireless receiver, 32 first acquisition unit, 34 judgment unit, 36 communication unit, 38 second Acquisition unit, 40 detection unit, 42 control unit, 44 wireless transmission unit, 50 communication unit, 52 packet signal buffer unit, 54 judgment unit, 56 detection unit, 58 packet signal distribution unit, 100 communication system.

Claims (8)

The first acquisition unit that acquires the first data from the terminal device,
The second acquisition unit that acquires the second data from the control device,
A determination unit that compares the quality of the first data acquired by the first acquisition unit with the quality of the second data acquired by the second acquisition unit.
Based on the comparison result of the determination unit, the transmission unit that transmits at least a part of the first data and the second data having the higher quality, and the transmission unit.
Equipped with
The second acquisition unit acquires, as the second data, the data selected as the highest quality data by the control device from the plurality of data received from the terminal devices by each of the plurality of base station devices. Characteristic base station equipment. The first acquisition unit that acquires the first data from the terminal device,
The second acquisition unit that acquires the second data from the control device,
A determination unit that compares the quality of the first data acquired by the first acquisition unit with the quality of the second data acquired by the second acquisition unit.
Based on the comparison result of the determination unit, the transmission unit that transmits at least a part of the first data and the second data having the higher quality, and the transmission unit.
Equipped with
The first acquisition unit acquires a plurality of first data, and each of the plurality of first data includes time information indicating a time received from the terminal device.
The second data acquired by the second acquisition unit includes time information and includes time information.
The determination unit compares the quality of the first data and the quality of the second data when the difference between the time information included in the first data and the time information included in the second data satisfies a predetermined condition. A base station device characterized by that. The first acquisition unit that acquires the first data from the terminal device,
The second acquisition unit that acquires the second data from the control device,
A determination unit that compares the quality of the first data acquired by the first acquisition unit with the quality of the second data acquired by the second acquisition unit.
Based on the comparison result of the determination unit, the transmission unit that transmits at least a part of the first data and the second data having the higher quality, and the transmission unit.
Equipped with
The transmission unit is a base station apparatus characterized in that the transmission power when transmitting the first data is smaller than the transmission power when transmitting the second data . The first acquisition step of acquiring the first data from the terminal device,
The second acquisition step of acquiring the second data from the control device,
A comparison step that compares the quality of the acquired first data with the quality of the acquired second data,
Based on the comparison result, the transmission step of transmitting at least a part of the first data and the second data having the higher quality, and
Including
In the second acquisition step, the data selected by the control device as the highest quality data from the plurality of data received from the terminal devices by each of the plurality of base station devices is acquired as the second data . Characteristic transmission method. The first acquisition step of acquiring the first data from the terminal device,
The second acquisition step of acquiring the second data from the control device,
A comparison step for comparing the quality of the acquired first data with the quality of the acquired second data,
Based on the comparison result, the transmission step of transmitting at least a part of the first data and the second data having the higher quality, and
Including
The first acquisition step acquires a plurality of first data, and each of the plurality of first data includes time information indicating a time received from the terminal device.
The second data acquired in the second acquisition step includes time information and includes time information.
The comparison step compares the quality of the first data and the quality of the second data when the difference between the time information contained in the first data and the time information contained in the second data satisfies a predetermined condition. A transmission method characterized by that. The first acquisition step of acquiring the first data from the terminal device,
The second acquisition step of acquiring the second data from the control device,
A comparison step for comparing the quality of the acquired first data with the quality of the acquired second data,
Based on the comparison result, it is a program for causing a computer to execute a transmission step of transmitting at least a part of the first data and the second data having higher quality .
In the second acquisition step, the data selected by the control device as the highest quality data from the plurality of data received from the terminal devices by each of the plurality of base station devices is acquired as the second data. Characterized program. The first acquisition step of acquiring the first data from the terminal device,
The second acquisition step of acquiring the second data from the control device,
A comparison step for comparing the quality of the acquired first data with the quality of the acquired second data,
Based on the comparison result, it is a program for causing a computer to execute a transmission step of transmitting at least a part of the first data and the second data having higher quality .
The first acquisition step acquires a plurality of first data, and each of the plurality of first data includes time information indicating a time received from the terminal device.
The second data acquired in the second acquisition step includes time information and includes time information.
The comparison step compares the quality of the first data and the quality of the second data when the difference between the time information contained in the first data and the time information contained in the second data satisfies a predetermined condition. A program characterized by that . The first acquisition step of acquiring the first data from the terminal device,
The second acquisition step of acquiring the second data from the control device,
A comparison step for comparing the quality of the acquired first data with the quality of the acquired second data,
Based on the comparison result, it is a program for causing a computer to execute a transmission step of transmitting at least a part of the first data and the second data having higher quality .
The transmission step is a program characterized in that the transmission power when transmitting the first data is smaller than the transmission power when transmitting the second data .

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