Radio-parameter control in mobile radio communications system

The present invention relates to a mobile radio communication system and a method for controlling radio parameters thereof.

[0002] Conventional technology As shown in FIG. 2, a conventional mobile wireless communication system controls a wireless network control device (RNC) connected to a core network and a wireless network control device accommodated in the wireless network control device. It has a radio base station device (BTS) and a mobile device (MS) that moves within the radio area of the radio base station device. The radio base station device and the mobile device set the radio parameters received from the radio network control device (the reference level for transmission power control set for the radio base station device and the mobile device, and the threshold value used for determining whether or not to perform handover. Collectively, it is called "wireless parameter"), and wireless communication is performed.

[0003] The wireless network control device makes reception level measurement, interference level measurement, and other monitor requests to the wireless base station device and the mobile device, and sets a reference level for transmission power control based on the received monitor result. And determine whether to perform handover.

[0004] In this system, the wireless network control device sets the transmission power control reference power and determines whether or not to perform handover based on the monitoring results from the wireless base station device and the mobile device. However, although the position of the mobile device changes with time and the propagation environment changes accordingly, there is a problem that it is not possible to prepare for the change in the propagation environment by changing the set value of the radio parameter in advance.

[0005] On the other hand, as a technique for controlling the set value of the radio parameter at the time of handoff, state monitoring for measuring the electric field strength of the pilot signal from each radio base station device in the overlapping (boundary) area of the two radio areas. A technique has been proposed in which a device is provided and the set value of the radio parameter is controlled according to the measurement result of the electric field strength by the state monitoring device. (Refer to Patent Document 1.) [Patent Document 1] Japanese Unexamined Patent Publication No. 2001-136558 (pages 1-3, FIG. 1) [0006] [Problems to be Solved by the Invention] The above-mentioned prior art (Patent Document 1 technology) In), since the state monitoring device is installed only in the overlapping area of the radio area, the radio parameter according to the measurement result of the electric field strength of the downlink signal from the radio base station device only when the mobile device approaches the overlapping area. It is not possible to control the set value of.

[0007] An object of the present invention is a mobile wireless communication system that enables preset value control of wireless parameters for a mobile device approaching an arbitrary position specified in advance in a wireless area, and a wireless parameter control method thereof. Is to provide.

[Means for Solving the Problems] The mobile wireless communication system according to claim 1 of the present invention wirelessly transmits a downlink signal and receives an uplink signal, and is a mobile device in the wireless area of its own station. It has a position measuring means for detecting the current position of the own device, and wirelessly communicates between the wireless base station device that controls the communication of the wireless base station device and the corresponding wireless base station device while arbitrarily moving in the wireless area. A mobile device that receives a downlink signal and transmits an uplink signal, transmits and receives communication information of a user, and transmits current position information, and a radio that is arranged at a predetermined position in the radio area and corresponds to the radio. One or more fixed terminals that monitor the downlink signal from the base station apparatus, create monitor information, and transmit it as an uplink signal to the wireless base station apparatus, and the wireless base station apparatus are accommodated, and the wireless base station is accommodated. The communication between the mobile terminal and the other party is controlled through the device, the current position information from the mobile terminal is received to recognize the moving direction, and the monitor information from the fixed terminal is received, accumulated, and statistically processed. Based on the statistical processing result, it has the mobile device approaching the arrangement position of the fixed terminal and the wireless network control device that controls the radio parameters for the corresponding radio base station device in advance.

[0009] The mobile wireless communication system according to claim 2 of the present invention is a wireless base station device that wirelessly transmits a downlink signal and receives an uplink signal to control communication of a mobile device in the wireless area of its own station. And a position measuring means for detecting the current position of the own device, and wirelessly receiving a downlink signal and an uplink signal between the wireless base station apparatus and the corresponding wireless base station apparatus while arbitrarily moving in the wireless area. A mobile device that transmits, transmits and receives user communication information, and transmits current position information, and is placed at a predetermined position in the wireless area to monitor downlink signals from the corresponding wireless base station device. To create monitor information, accommodate one or more fixed terminals that output through a wired transmission line, and the wireless base station device, and control communication between the mobile terminal and the other party through the wireless base station device. The current position information from the mobile terminal is received to recognize the moving direction, and monitor information from the fixed terminal through the wired transmission path is received, accumulated and statistically processed, and based on the statistical processing result, the said It has the mobile device approaching the arrangement position of the fixed terminal and the wireless network control device that controls the radio parameters for the corresponding radio base station device in advance.

[0010] The mobile wireless communication system according to claim 3 of the present invention is, in the mobile wireless communication system according to claim 1 or 2, maintenance for notifying the wireless network control device of weather information in the wireless area. It has an operation center, and the wireless network control device has a configuration in which the statistical processing including the weather information is performed.

[0011] The mobile wireless communication system according to claim 4 of the present invention is the mobile wireless communication system according to claim 1, 2 or 3, and is CDMA as a wireless access system between the wireless base station apparatus and the mobile device. A method is adopted, and the fixed terminal has a configuration in which the received power value of the pilot channel transmitted from the radio base station apparatus is used as the monitor information.

[0012] The wireless parameter control method according to claim 5 of the present invention performs wireless communication between a wireless base station apparatus having jurisdiction over a wireless area and the wireless base station apparatus while arbitrarily moving within the wireless area. In a wireless parameter control method in a mobile wireless communication system including a mobile device to be performed and a wireless network control device that accommodates the wireless base station device and controls wireless communication of the mobile device through the wireless base station device. A fixed terminal arranged at a predetermined position in the wireless area monitors the downlink signal from the wireless base station device, creates monitor information, transmits the monitor information to the wireless network control device, and uses the mobile device. During communication through the wireless base station device, the built-in position measuring means acquires the current position information and notifies the wireless network control device, and the wireless network control device uses the current position information from the mobile device to obtain the current position information. Recognizes that is approaching the arrangement position of the fixed terminal, and has a step of preliminarily correcting the radio parameters for the mobile device and the corresponding radio base station device based on the result of statistically processing the monitor information.

[0013] The wireless parameter control method according to claim 6 of the present invention is the wireless parameter control method according to claim 5, wherein the wireless network control device statistically processes the monitor information including the weather information of the wireless area. Has a step of performing.

BEST MODE FOR CARRYING OUT THE INVENTION First, an outline of the present invention will be described. In the present invention, the monitor information (reception level value of the pilot channel signal from the wireless base station device) received from a fixed terminal arranged at an arbitrary location in the wireless area of each wireless base station device is transmitted by the wireless network control device. Statistical processing (calculation of average value in a predetermined time unit) is performed and stored in the memory. The mobile device has a position detecting means of its own device and notifies the current position information to the wireless network control device. The wireless network control device corrects the wireless parameters in advance by referring to the statistical information stored in the memory based on the number of mobile units around the mobile unit, the moving direction, the current time, the weather, and the like. It becomes possible for the radio base station device and the mobile device to communicate with each other based on more accurate radio parameters. Since the statistical results stored in the memory are constantly updated, it is possible to flexibly respond to changes in the geographical environment around the fixed terminal installation location. Further, by installing a plurality of fixed terminals, the accuracy of the statistical result can be improved regardless of the position of the mobile device.

[0015] Even when the transmission line connecting the fixed terminal and the wireless network control device is a wireless line via a wireless base station, there is no increase in interference power with respect to the downlink wireless line, and monitor information is also communicated with respect to the uplink wireless line. Only the amount of interference power required for this is increased. If the increase in the interference component related to the uplink wireless line cannot be ignored, the fixed terminal and the wireless network control device may be connected by a wired line.

[0016] Next, embodiments of the present invention will be described in detail with reference to the drawings.

[0017] FIG. 1 is a block configuration diagram showing an embodiment of the present invention. In FIG. 1, the mobile wireless communication system of this example is an example applied to a CDMA (Code Division Multiple Access) communication system, and is a core network 10 composed of an exchange or the like and a core network 10. The wireless network control device (RNC) 20 housed in the wireless network control device 20, the maintenance operation center 30 connected to the wireless network control device 20, and each wireless area 41 (41-1, 41-2) housed in the wireless network control device 20. ), And multiple fixed terminals (FS) 50 (50-1 to 50) arranged at predetermined positions in each radio area 41. -4) and a mobile device (MS) 60 having a GPS position measuring device 61 for detecting the current position by the received signal from the GPS satellite 70 and arbitrarily moving in each radio area 41.

[0018] Although only one wireless network control device (RNC) 20 is shown in FIG. 1, a plurality of wireless network control devices (RNC) 20 can be provided. Along with this, wireless base station equipment (BTS) 40 and fixed terminal (FS) 50 can also be added. In addition, any number of mobile devices (MS) 60 can be provided.

[0019] In FIG. 1, the radio area 41 of each radio base station apparatus (BTS) 40 is limited to only one area (cell), but the present invention is not limited to this, and a plurality of areas (sectors) are not limited thereto. ) Can be divided. In this case, the fixed terminal (FS) 50 is also placed in each sector.

[0020] Other networks accommodating terminals can be connected to the core network 10, and communication between the terminal and the mobile device 60 (MS) and between the mobile devices 60 is possible.

[0021] The maintenance operation center 30 manages information necessary for system operation, and gives instructions for various processes to the wireless network control device 20. In addition, the maintenance operation center 30 grasps the weather information of each wireless area 41 and transmits it to the wireless network controller (RNC) 20. This weather information may be transferred from an appropriate meteorological observation system or may be manually entered by the operator.

The wireless network control device (RNC) 20 is an ordinary means for controlling communication of the mobile device 60 via the wireless base station 40 based on various wireless parameters and the position information of the mobile device (MS) 60. In addition to (not shown), the monitor information storage unit 21 that stores monitor information (pilot channel downlink received power value, etc.) and the stored monitor information are statistically processed, and wireless parameters (reference level for transmission power control) are processed. It also has a statistical processing unit 22 that is reflected in (such as a threshold used for determining whether or not to perform handover). Calendar information such as the day of the week and the current time generated by a clock circuit (not shown), weather information from the maintenance and operation center 30, and the like are input to the statistical processing unit 22, and the statistics of monitor information are taken into consideration. Performs processing (calculation of the average value of downlink reception power and signal deterioration degree in predetermined time units).

The wireless network control device (RNC) 20 is connected to each wireless base station device (BTS) 40 through a wired transmission line. The wireless network controller 20 can also be connected to each fixed terminal (FS) 50 by a wired transmission line (shown by a dotted line in FIG. 1). The monitor information from each fixed terminal 50 is directly transmitted to the wireless network control device 20 through this wired transmission line, or is transmitted to the wireless network control device 20 via the wireless link with the wireless base station device 40.

[0024] Each radio base station apparatus (BTS) 40 is arranged so that the service area of the system can be covered by its own radio area 41 while partially overlapping. As described above, each radio area 41 can be divided into a plurality of (for example, three) sectors.

[0025] In each fixed terminal (FS) 50, the mobile device (MS) 60 is concentrated in a place where the radio wave propagation environment is liable to fluctuate within the radio area 41 (in the sector when divided into sectors). It is placed in a place that tends to be. Each fixed terminal 50 receives a known downlink common pilot channel (CPICH: Common Pilot Channel) signal (pilot signal: reference signal) from the corresponding radio base station apparatus (BTS) 40, and receives the signal by sector / frequency. It monitors the power level and signal deterioration status, and transmits it as monitor information to the wireless network control device (RNC) 20 via the wireless base station device 40 or directly.

[0026] The mobile device (MS) 60 desires by moving within or between each radio area 41 and communicating with the radio base station device (BTS) 40 corresponding to the radio area 41 in which the mobile device (MS) 60 stays, through a radio link. Communicate with the other party. At that time, the mobile device 60 notifies the wireless network control device (RNC) 20 of the position information of its own device obtained based on the received signals from the plurality of GPS satellites 70 through the radio base station device 40.

[0027] Next, the operation will be described.

[0028] Each fixed terminal (FS) 50 (50-1 to 50-4) is located in each radio area 41 (41-1, 41-2) in advance in a place where the radio wave propagation environment is likely to fluctuate. MS) 60 is located in a place where it tends to be concentrated.

[0029] Each fixed terminal 50 constantly receives the pilot channel transmitted by the corresponding radio base station apparatus (BTS) 40 (40-1, 40-2), measures the reception level thereof, and monitors the measurement result as monitor information. Notify the wireless network controller (RNC) 20 via a random access channel as (monitor information of each peripheral area 51 (51-1 to 51-4)).

[0030] Each mobile device (MS) 60 communicates with the other party through the radio base station device 40 having jurisdiction over the existing radio area 41 under the control of the radio network control device 20. Each mobile device 60 also receives a signal from the GPS satellite 70 by the built-in GPS position measuring device 61, detects the current position of its own device, and notifies the wireless network control device 20. Instead of calculating the current position from the data received from the GPS satellite 70 by each mobile device 60, the data received from the GPS satellite 70 is transferred to the wireless network control device 20 and the mobile device 20 is used to transfer the data received from the GPS satellite 70. It is possible to calculate the current position of 60.

The wireless network control device 20 calculates the current position, the moving direction, the moving speed, and the like of the mobile device 60 based on the current position information from each mobile device 60. Further, the wireless network control device 20 can recognize the number of other mobile devices existing in the vicinity of each mobile device 60.

[0032] The wireless network control device 20 also stores the monitor information from each fixed terminal 50 in the monitor information storage unit 21, and statistically processes the monitor information in the statistical processing unit 22. The content of the statistical processing is to calculate the downlink received power for each day of the week and time zone, and the average value of fluctuations in the degree of signal deterioration.

Here, as shown by an arrow in FIG. 1, while the mobile device 60 is communicating, the radio area 41-1 of the radio base station device 40-1 to the radio area 41-2 of the radio base station device 40-2. The case of moving to will be described as an example.

[0034] The mobile device 60 periodically measures the current position of its own device as it moves, and notifies the wireless network control device 20 of the obtained current position information.

[0035] The wireless network control device 20 performs reception level measurement, interference level measurement, and other monitoring requests to the wireless base station device 40-1 and the mobile device 60 during communication, and performs the wireless base station device 40-1 and the mobile device 60. Based on the monitor result and position information received from the mobile device 60, the current position of the mobile device 60 and the future traveling direction are recognized, the transmission power control reference level is set, and whether or not handover is performed is determined.

[0036] In the example shown in FIG. 1, the mobile device 60 passes through the peripheral area 51-2 of the fixed terminal 50-2 in the wireless area 41-1 and then passes through the fixed terminal 50-3 in the wireless area 41-2. It is estimated to reach the surrounding area 51-3.

[0037] In the wireless network control device 20, the fixed terminal 50-2 and the fixed terminal 50 stored in the corresponding monitor information storage unit 21 before the mobile device 60 approaches the areas 51-2 and 51-3, respectively. With reference to the result of the statistical processing of -3, the radio parameters for the radio base station devices 40-1 and 40-2 and the mobile device 60 are corrected in advance. For example, if the reception level in Area 51-2 is expected to be lower than usual due to conditions such as the day of the week, time of day, and weather, the radio base station device 40-1 (or 40-2) or move. Instruct the machine 60 to increase the transmission power for communication by that amount. In addition, even if interference is expected, such as when there are many other mobile devices in Area 51-2, the wireless network control device 20 can recognize this, so the transmission power to the mobile device 60 can be increased. Alternatively, it is possible to appropriately give a correction instruction in advance of lowering.

[0038] In the above description, the wireless access system is the CDMA system, but the present invention is not limited to this, and can be applied to any system that transmits a known reference pilot signal to the radio area under the jurisdiction of the base station. is there.

According to the present invention, monitor information received from a fixed terminal is statistically processed by a wireless network control device and stored in a memory, and the number of mobile devices in the vicinity, the moving direction of the mobile devices, and the current time are stored. , The radio base station device and the mobile device communicate with each other based on the more accurate radio parameters by correcting the radio parameters in advance with reference to the statistical information stored in the memory under the condition of weather, etc. Is possible. Since the statistical results stored in the memory are constantly updated, it is possible to flexibly respond to changes in the geographical environment around the fixed terminal installation location.

BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1] Fig. 1 is a system configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional mobile communication system.

[Code description] 20 Wireless network controller (RNC) 30 Maintenance and operation center 40 (40-1, 40-2) Radio base station device (BTS) 41 (41-1, 41-2) Radio area 50 (50- 1 ~ 50-4) Fixed terminal (FS) 51 (51-1 ~ 51-4) Area around fixed terminal 60 Mobile (MS)