JP2006086923A - Digital radio system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital radio system capable of transmitting information to a mobile station, which cannot receive transmission from a base station. <P>SOLUTION: A digital radio system includes a base station 300 and two or more mobile stations 301, 302, 303. From each information on position transmitted from two or more mobile stations, the base station 300 judges the first mobile station, which cannot receive the information from the base station, and the second mobile station 301 locating near to the first mobile station 302. The base station 300 directs the second mobile station 301 to replace the self transmission frequency by the transmission frequency of the base station 300 and transmit the previously decided information to the first mobile station 302. The second mobile station 301, which received the direction, transmits the information to the first mobile station 302. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to communication control in a digital wireless system.

  The configuration of a conventional digital radio system will be described with reference to FIG. 3 (not related to the known literature invention). The digital radio system shown in FIG. 3 is composed of two types of equipment, a base station 300 and mobile stations 301, 302, and 303, and uplink and downlink pair radio frequencies are assigned to the system and transmitted from the base station 300. The transmitted wave is referred to as a downstream wave f1, and the transmitted wave transmitted from the mobile station 301 in the transmission state is referred to as an upstream wave f2. Communication between the base station 300 and the mobile stations 301, 302, and 303 or between the mobile stations 301, 302, and 303 and the mobile stations 301, 302, and 303 via the base station 300 is performed using these uplink and downlink pair waves.

  In the example illustrated in FIG. 3, the mobile station 301 is in a transmission state due to a press talk, and the information transmitted from the mobile station 301 is in the base zone via the base station 300, and the other reception state mobile station 302. , 303, the base station 300 receives the upstream wave f2 from the mobile station 301 and transmits it in place of the downstream wave f1. It is not possible to make a call from the mobile stations 302 and 303 that are receiving. Further, in the base station 300, all the location information of the mobile station is managed by the base station 300 based on the location information from the mobile station, and is managed to be updated at regular time intervals.

  A region surrounded by an ellipse including the base station 300 and the mobile stations 301, 302, and 303 in FIG. 3 is a base zone of the base station 300. Such a system is called a SCPC system (Single Channel Per Carrier), and is a system that allocates one carrier per voice channel. As a standard of the system, “Narrowband Digital Communication System (SCPC / FDMA) Standard (ARIB) STD T-61), which defines the data frame format and connection procedure, where a base station or a mobile station makes a call according to the connection procedure according to the standard by the press talk, The station is a digital wireless system that only receives and can make a call after the other party completes the call.

  The voice reception operation of the mobile station used in the digital radio system shown in FIG. 3 will be described with reference to FIG. FIG. 2 is a block diagram showing a functional configuration of the mobile station. The system control unit 102 that demodulates and analyzes the received signal and thereby recognizes voice reception issues an instruction for voice reception to the channel codec unit 104.

  The voice frame from the base station is demodulated by the RE unit 101 of the mobile station, the modulated signal is demodulated by the A / D converter in the modulation / demodulation unit 103, and the channel codec unit 104 as a predetermined numerical sequence by a predetermined demodulation method. Is output. The channel codec unit 104 outputs a numerical value at a predetermined position in the frame to the audio codec unit 105, and the audio codec unit 105 decodes the input numerical value to audio and outputs it to the audio input / output unit 106. 106 is output as sound.

  The LCD display unit 201 is used for displaying the status of the wireless device and displaying messages from the base station, and the LED display unit 201 displays the function supplementing the LCD display unit 201 and the power state of the wireless device by turning on and off. . A key input unit 203 is used to select a radio station function or to select a partner station when making an individual call. The buzzer unit 204 is used to sound an audible sound, and further notifies the operator of the state of the wireless device by vibration using the vibration motor 205.

  In the above-described PressTalk digital wireless communication system, among mobile stations using the same system, sometimes even when the base station is in a transmission state, the received electric field strength is not at a level that can be demodulated, and communication from the base station is not possible. Some mobile stations cannot be received. If it can move to a position where the received electric field strength can be demodulated, information can be obtained by receiving communication from the base station again. However, if the signal cannot be received, there is a problem in terms of system efficiency. is there.

  An object of the present invention is to provide a digital radio system capable of sending information to a mobile station that cannot receive communication from a base station.

  The present invention provides a digital radio system having a base station and a plurality of mobile stations, wherein the base station cannot receive information from the base station from position information transmitted from each of the plurality of mobile stations. And a second mobile station close to the first mobile station, and information determined in advance for the second mobile station by replacing the transmission frequency of the local station for a predetermined period of time with the transmission frequency of the base station Is transmitted to the first mobile station, and the second mobile station receiving the instruction transmits the information to the first mobile station.

  ADVANTAGE OF THE INVENTION According to this invention, the digital radio system which can send information also to the mobile station which cannot receive the communication from a base station can be obtained.

  Embodiments according to the present invention will be described in detail with reference to FIGS. 1, 4, 5, and 6.

  FIG. 1 is a diagram showing a configuration of an embodiment of a digital radio system according to the present invention. In FIG. 1, in response to an instruction from the base station 300, the received electric field strength is deteriorated by a building between the mobile station 301 that transmits at the downlink frequency f <b> 1 of the base station 300 and the base station 300 and the mobile station 302. 3 shows an example of a mobile station 302, a mobile station 303 in which reception field strength is not degraded, and a range 310 in which the reception field strength is degraded in the base zone.

  Each of the mobile stations 301, 302, and 303 has a means for determining the received electric field strength, a means for measuring its own position, a means for transmitting the measured position information to the base station 300, and an instruction from the base station 300. Means for changing the transmission frequency of the own station to the transmission frequency of the base station 300, and the base station 300 manages the position information from the mobile stations 301, 302, 303, and the mobile station 302 from the position information. -301 and means for determining the perspective relationship between the mobile stations 302-303.

  The base station 300 manages the location information of all the mobile stations 301, 302, and 303, and performs management for updating at regular time intervals.

  In the example of FIG. 3, the mobile station 302 is in a state 310 in which the position information cannot be updated for a certain period in a range 310 where the received electric field strength deteriorates caused by the structure between the mobile station and the base station 300. Based on the update status of the location information of the mobile stations 301, 302, 303 managed by the base station 300, the location information from the mobile station 302 is not updated for a certain period, so that the base station 300 determines that reception is not possible. . In addition, the base station 300 determines the mobile station 301 closest to the mobile station 302 from the position information.

  In such a state, when an event occurs in which some information is desired to be transmitted from the base station 300 to the mobile stations in the system, the base station 300 first transmits information to all the mobile stations 301, 302, and 303. Subsequently, the mobile station 301 is instructed to transmit the predetermined information by changing the transmission frequency of the local station to the transmission frequency of the base station 300 for a certain period of time by an individual call. The mobile station 301 autonomously restores the frequency relationship after transmission for a certain period and shifts to the reception state. As a result, the mobile station 301 that has received the instruction transmits the information to the mobile station 302 whose position information does not change for a certain period of time, notifying that the base station 300 has notified some information.

  Although the mobile station 302 that has not received the first information of the base station 300 does not recognize the state of the base station 300, the mobile station 302 is in the base zone due to the deterioration of the received electric field strength and the information on its own position. It is recognized that the mobile phone is out of service and cannot be received from the base station 300. In such a state, in response to an instruction from the base station 300, the received electric field strength of transmission from the mobile station 301 that is transmitting information is input larger than that from the base station 300, and is received, analyzed, and confirmed. As a result, it is possible to recognize whether the base station 300 is transmitting information and receive information from the mobile station 301.

  FIG. 4 is a diagram illustrating a configuration of an audio frame transmitted by the base station 300. Elements constituting the audio frame are defined in advance by the standard.

  FIG. 5 is a diagram clarifying the relationship between the frames on the time axis of the downlink from the base station 300 and the uplink from the mobile station 301 described in FIG. The mobile station 301 instructed by the base station 300 described with reference to FIG. 1 changes the frequency, and then maintains the relationship between the downlink and the uplink, and determines the timing at which the mobile station transmits the downlink signal. Transmit according to the timing.

  FIG. 6 is a diagram showing a bit arrangement of the RICH channel in the standard shown in FIG. An undefined 600 is a part open to the user. For example, if it is information from the base station 300, bits 8 and 7 are set to “00”, and the mobile station 301 transmits according to the instruction of the base station 300. In this case, the setting of “11” is determined in advance in the system.

  Thus, the mobile station 302 that has demodulated this part can determine that the reception is from the mobile station 301 that has received an instruction from the base station 300, and the mobile station that can receive the frames transmitted by the base station 300 until then. 301 can recognize that this demodulated frame is not addressed to the own station together with the mismatch of individual calls. Further, the mobile station 302 that cannot receive the frame transmitted by the base station 300 can be more reliably recognized together with the individual call.

  Here, there is another undefined portion in the standard described above. For example, information on the base station 300 can be transmitted from the mobile station 301 to the mobile station 302 by using the undefined 601.

  As described above, according to the present embodiment, when the base station recognizes a mobile station whose location information is not updated in the system for a certain period as a mobile station that cannot be received, and wants to notify the mobile station of information, By selecting the mobile station closest to the mobile station and issuing an individual instruction, the information transmitted by the base station can be transmitted through the mobile station. These are performed based on instructions from the base station and do not require the operation of the mobile station operator.

It is a figure which shows the structure of embodiment of the digital radio system which concerns on this invention. It is a block diagram which shows the function structure of a mobile station. It is a figure which shows the structure of the conventional digital radio system. It is a figure which shows the structure of the audio | voice frame utilized by this invention. It is a figure which shows the offset of the audio | voice frame utilized by this invention. It is a figure which shows the bit allocation figure of the RICH channel in the audio | voice frame utilized by this invention.

Explanation of symbols

  101: RF unit 102: System control unit 103: Modulation / demodulation unit 104: Channel codec unit 105: Audio codec unit 106: Audio input / output unit 107: Audio memory 201: LCD display unit 202: LED display , 203: Key input unit, 204: Buzzer unit, 205: Vibration motor unit, 300: Base station, 301, 302, 303: Mobile station, 600, 601: Undefined area.

Claims (1)

  In a digital radio system having a base station and a plurality of mobile stations, the base station can receive from the position information transmitted from each of the plurality of mobile stations a first mobile station that cannot receive information from the base station and the first mobile station A second mobile station that is close to the first mobile station, and the first mobile station replaces the transmission frequency of the base station with the transmission frequency of the base station for a predetermined period of time for the first mobile station. A digital radio system characterized by instructing to transmit to the mobile station, and the second mobile station receiving the instruction transmits the information to the first mobile station.

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