JP2012227792A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system capable of shifting to a voice call after confirming completion of establishment of synchronization, when a mobile station performs call connection to a base station.SOLUTION: A radio communication system comprises a base station and a mobile station which performs radio communication with the base station, and transmits communication request signals for synchronizing with the base station at previously stored N transmission times in communicating with the base station. The mobile station shifts to reception status after transmitting transmission termination information of the communication request signals included in Nth communication request signal. The base station has means for transmitting a signal notifying the mobile station of completion of establishment of the synchronization, when extracting the transmission termination information included in the communication request signal after the reception of the communication request signal and the establishment of the synchronization.

Description

  The present invention relates to a radio communication system including a base station and a mobile station, and more particularly to confirmation of synchronization establishment at the time of call connection from a mobile station to a base station.

  In digital wireless communication, as a method for establishing communication between two points (for example, between a mobile station and a base station) and performing communication, a method of transmitting a synchronous burst signal has been conventionally used. For example, by transmitting a synchronous burst signal as a communication request signal when performing call connection from a mobile station to a base station and performing call connection, it is possible to reliably perform subsequent voice communication, data communication, etc. Become.

As an example of communication using such a synchronous burst signal, for example, there is a digital radiotelephone device described in Patent Document 1. In Patent Document 1, once the value of the superframe synchronization counter SSC of the downlink synchronization burst SB3 is erroneously received, it is difficult to proceed to the transmission / reception of the communication channel TCH, or the transmission shifts from the transmission / reception of the synchronization burst SB to the transmission / reception of the communication channel TCH. To solve the conventional problem that the synchronization burst SB or the communication channel TCH sometimes took time without being clear, and to shorten the time required for resynchronization or switching to the communication channel It is intended.
Japanese Patent Application Laid-Open No. 08-84109

  In Patent Document 1, a duplex communication system using a telephone device is used, but a communication device that uses a simplex communication system such as a transceiver is also employed in a fire fighting radio or the like. In the case of the simplex system, communication with the other party cannot be received during transmission, so it is necessary to decide the communication method in advance.

The flow from the transmission of the communication request signal between the mobile station 12 and the base station 11 to the start of the voice call in the case of such a one-wave or two-wave simplex system will be described with reference to the schematic diagram of FIG. First, when a call connection is made from the mobile station 12, a communication request signal including its own identification number ID and a synchronization burst signal is continuously transmitted to the base station for a preset number of times. In the example of FIG. 4, transmission is performed six times as the predetermined number of times. This predetermined number of times is set to the number of times that the base station 11 can establish synchronization with the mobile station with certainty if the number of times of transmission is transmitted.
In the fire fighting radio, the transmitter transmits a synchronous burst signal, which is a communication request signal, a plurality of times, and then shifts to voice communication. Therefore, synchronization for communication with the base station 11 as the counterpart station is performed. Therefore, it is necessary to set the number of times that synchronization can be established reliably. In the example of FIG. 4, the base station 11 is synchronized by receiving the third communication request signal, but thereafter, the mobile station 12 transmits the fourth to sixth communication request signals.

  Thereafter, the mobile station 12 starts transmitting the audio signal on the assumption that synchronization is established with the base station 11 by transmitting the communication request signal six times. Since synchronization is established with the base station 11, the audio signal is transmitted to the base station 11 without any problem.

  Here, since the optimal number of transmissions of the communication request signal changes as appropriate according to the positional relationship between the base station 11 and the mobile station 12, the radio wave condition, etc., it is difficult to set the optimal number of times in advance. In many cases, the number of transmissions was given. However, as shown in FIG. 4, when the synchronization with the base station 11 has already been established by the third transmission of the communication request signal, the transmission of the fourth to sixth communication request signals is substantially performed. Since this is an unnecessary operation, there is a demerit that the time until the start of the call is delayed. However, if the number of transmissions of the communication request signal set in advance is set to a small number, the mobile station 12 starts a voice call before the synchronization is established. There is a problem that a situation in which the caller is unknown occurs. These problems are caused by the fact that there is no means for confirming the status of the other party on the way, such as whether or not the establishment of synchronization is completed due to the operation of the simplex system.

  The present invention has been made in view of the above problems, and confirms that establishment of synchronization is completed when a call connection is made from a mobile station operating in a simplex mode to a base station. An object of the present invention is to provide a wireless communication system capable of shifting.

  Claim 1 of the present invention comprises a mobile station that performs radio communication with the base station, and when the mobile station communicates with the base station, a communication request signal for synchronizing with the base station is previously provided. In the wireless communication system that transmits the stored transmission number N, the mobile station transmits the N-th communication request signal including transmission end information of the communication request signal, and then enters a reception state. When synchronization is established by receiving the communication request signal and the transmission end information included in the communication request signal is extracted, a synchronization establishment signal indicating that synchronization is established is transmitted to the mobile station. A wireless communication system is characterized.

  According to a second aspect of the present invention, in addition to the first aspect, the mobile station includes a transmission counter that counts the number of transmissions of the communication request signal, and stores the count value of the transmission counter and the pre-stored in the communication request signal. A transmission system including the value of the number of transmissions performed, and transmitting that the count value of the transmission counter matches the value of the number of transmissions stored in advance as the transmission end information .

  According to a third aspect of the present invention, in addition to the first or second aspect, the base station receives a count value of the transmission counter included in the communication request signal when the communication request signal is received and synchronized. Extracted as a synchronization establishment count value, transmits the synchronization establishment count value as the synchronization establishment signal, the mobile station receives the synchronization establishment count value, and uses the synchronization establishment count value as the number N of transmissions of new communication request signals. A wireless communication system is characterized by storing.

  According to the first aspect of the present invention, the mobile station transmits the communication request signal including the transmission end information of the communication request signal included in the final transmission, and then enters the reception state, and the base station receives the communication request signal. When the transmission end information included in the communication request signal is extracted, a synchronization establishment signal indicating that synchronization is established is transmitted to the mobile station. Since it is possible to shift to a voice call after recognizing that synchronization has been established, there is no situation where the call is interrupted or the caller is unknown. When a signal notifying that synchronization has been established cannot be received, it is also possible to perform processing such as moving to transmission of a communication request signal again without shifting to a voice call.

  According to the second aspect of the present invention, the mobile station includes a transmission counter that counts the number of transmissions of the communication request signal, and sets the count value of the transmission counter and the value of the number of transmissions stored in advance in the communication request signal. The transmission end information indicates that the count value of the transmission counter matches the value of the number of transmissions stored in advance, so that the total number of transmissions of the communication request signal and the number of transmissions The end of transmission was understood.

  According to the invention of claim 3, the base station extracts the count value of the transmission counter included in the communication request signal when the communication request signal is received and synchronized as a synchronization establishment count value, Since the synchronization establishment count value is transmitted as the synchronization establishment signal, the mobile station receives the synchronization establishment count value and stores the synchronization establishment count value as the number N of transmission times of a new communication request signal. When a call connection is made again to a base station that has made a call connection, if the newly stored communication request signal transmission count is smaller than the previous count, the communication request signal transmission count will be less than the previous count, and synchronization will occur early. Therefore, it is possible to eliminate the disadvantage that the time until the start of the call is delayed due to the transmission of an unnecessary communication request signal.

(A) is the schematic diagram showing the flow from the transmission of the synchronous burst signal between the mobile station 12 and the base station 11 of the single-wave simplex operation in the present invention to the start of the voice call, and (b) FIG. 5 is a schematic diagram showing a flow from the time when a call connection is made and a synchronization establishment count value from a base station is received to the start of a voice call at the time of call connection. It is a flowchart showing the flow of the process in the radio | wireless communications system by this invention. (A) is the schematic diagram showing the radio | wireless communication format of the synchronous burst signal, (b) is the schematic diagram showing the radio | wireless communication format of the audio | voice channel. It is the schematic diagram showing the flow from transmission of the synchronous burst signal between the mobile station 12 and the base station 11 of the operation | movement of the simplex system in a prior art to the start of a voice call.

  A radio communication system according to the present invention includes a base station and a mobile station that performs radio communication with the base station, and the mobile station communicates with the base station when communicating with the base station. In a wireless communication system for transmitting a request signal for a pre-stored number of transmissions N, the mobile station transmits a communication request signal including the communication request signal transmission end information to the Nth transmission, and then enters a reception state. The base station receives the communication request signal, establishes synchronization, and extracts the transmission end information included in the communication request signal, the synchronization establishment signal indicating that synchronization is established for the mobile station Is transmitted.

  A wireless communication system according to the present invention will be described with reference to the drawings. In the present invention, when a call connection is made from the mobile station 12 of the simplex operation to the base station 11, the establishment of synchronization is completed after the communication request signal is transmitted a plurality of times and before the voice call is started. It is possible to confirm this. Specifically, in the SCPC (Single Channel Per Carrier) system adopted for fire fighting radio, etc., it is assumed that at least the mobile station operates in the single-wave simplex system, and the mobile station calls the base station. By devising the synchronization burst signal that is transmitted when connection is established, it is possible to confirm the establishment of synchronization before shifting to a voice call without destroying the conventional wireless communication format.

  Here, the format of wireless communication in the present invention will be described with reference to FIG. In the wireless communication according to the present invention, signals are configured in units of frames (or packets) and wireless communication is performed, and the format in the frame is defined in detail. Here, each frame is composed of either a physical channel of a synchronization burst or a voice (communication) channel. FIG. 3A shows the radio signal format of the synchronization burst signal, which is the frame format of the synchronization burst signal. FIG. 3B shows a radio channel radio signal format, which is a frame format such as audio signal transmission and data transmission.

  Of the radio signal format of the synchronization burst, PICH is a parameter information channel, and the content of the synchronization burst signal is determined by this PICH. The PICH contains information such as identification information indicating a burst signal, message type information identifying a message type such as a communication request signal and a synchronization establishment signal, an identification information ID of a transmission station, and identification information of a transmission partner station. ing. If the message type is a communication request signal, the total number of transmissions of the communication request signal and the order information for each transmission are entered. If the message type is a synchronization establishment signal, information on the synchronization establishment count value is entered.

  The characteristics of the present invention will be described with reference to FIG. 1 in consideration of the above radio signal format. FIG. 1A is a schematic diagram showing a flow from transmission of a communication request signal to start of a voice call between the mobile station 12 and the base station 11 in the simplex operation in the present invention. First, when a call connection is made from the mobile station 12 to the base station 11, the communication request signal is transmitted N times, which is the number of transmissions of the communication request signal that is preset and stored in the memory. In the example of FIG. 1, N = 6 and six communication request signals are transmitted. Apart from the number of transmissions N, an initial value of the number of transmissions of the communication request signal is also stored in the memory. In the example of FIG. 1, it is assumed that the initial value = 6.

  In the example of FIG. 1A, the first and second communication request signals transmitted from the mobile station 12 cannot be received by the base station 11, but can be received without problems after the third time. In the base station 11, the recognition information ID of the mobile station 12 and the communication counter value included in the third communication request signal are set as a synchronization establishment count value, and memory (not shown) of the base station is used as information to be put on the synchronization establishment signal. ).

  The mobile station 12 switches to the reception state only for the period of the seventh frame after the sixth transmission, which is the final communication request signal (transmission count N). The communication request signal includes information on the number of times of transmission based on the transmission counter value and the number of transmissions N (N = 6 in FIG. 1A). Accordingly, in the final communication request signal, the transmission counter value and the number of transmissions N match, so this is transmission end information.

  Since the base station 11 obtains transmission end information included in the communication request signal and synchronization has already been established, after the transmission of the communication request signal from the mobile station is completed (the seventh frame in FIG. 1A). At this timing, a synchronization establishment signal is transmitted to notify the mobile station 12 that synchronization has been established. Information of synchronization establishment count value = 3 is added to this synchronization establishment signal. In the mobile station 12 that has received the synchronization establishment signal, the synchronization establishment count value = 3 is stored in the memory as the number of transmissions of a new communication request signal, and then the process proceeds to a voice call.

  FIG. 1B shows communication when the mobile station 12 that has made a call connection once and received the synchronization establishment signal from the base station 11 as shown in FIG. 1A makes a call connection to the mobile station 11 again. It is a schematic diagram showing the flow from transmission of a request signal to the start of a voice call. Since the mobile station uses the synchronization establishment count value = 3 included in the synchronization establishment signal as the number of times of transmission of a new communication request signal, transmission end information is added to the third communication request signal this time.

  As in FIG. 1A, the base station 11 completes establishment of synchronization with the third communication request signal and acquires transmission end information. Therefore, after the transmission of the communication request signal from the mobile station is completed ( A synchronization establishment signal is transmitted at the timing of the fourth frame). The mobile station 12 that has received the synchronization establishment signal at the timing of the fourth frame recognizes that synchronization has been established, and thereafter shifts to a voice call.

  In the mobile station 12, when the fourth frame after completion of transmission of the communication request signal is switched to the reception state but the synchronization establishment signal from the base station 11 cannot be received, the initial value of the number of transmissions of the communication request signal 6 is stored as the new communication count.

Next, the flow of the above processing in the base station 11 and the mobile station 12 will be described based on the flowchart of FIG. First, the flow of processing when a call connection is made from the mobile station 12 to the base station 11 will be described with reference to steps S11 to S15. First, the value of the transmission counter of the communication request signal is set to “1” (S11), and a communication request signal including the transmission counter value and the number N of transmissions is transmitted (S12). Thereafter, the value of the transmission counter is compared with the number N of transmissions of the communication request signal (S13). When the value of the transmission counter is smaller than the number N of transmissions of the communication request signal (S13-N), the value of the transmission counter is incremented by +1 (S14), and the communication request signal is transmitted according to the value of the transmission counter after the increment. (S12). Thereafter, until the value of the transmission counter = the number of transmissions N of the communication request signal, the value of the transmission counter is incremented by +1 to transmit the communication request signal. In step S13, the value of the transmission counter = the number of transmissions N of the communication request signal At the determined stage (S13-Y), a reception waiting state is entered in order to receive the synchronization establishment signal from the base station (S15).

  Next, the flow of processing in the base station 11 that has received the communication request signal will be described with reference to S31 to S39. The base station 11 stands by in a reception waiting state. Here, if any signal is received, it is determined whether it is a communication request signal (S31). If it is a communication request signal (S31-Y), the mobile station identification information ID, the value of the transmission counter, and the number N of transmissions are extracted from the communication request signal, and the transmission counter is used as the ID at the time of establishing synchronization and the synchronization establishment count value. Is stored in a memory (not shown) of the base station 11 (S32), and it is determined whether the transmission counter knowledge has reached the number N of transmissions (S34). If the transmission counter value has not reached the number of transmissions N (S34-N), a communication request signal sent continuously from the mobile station 12 is received (S35), and steps S34 to S35 are repeated until it reaches. When the transmission counter value reaches the number of transmissions N (S34-Y), it is determined as transmission end information, and the communication request signal from the mobile station ends, so that the base station determines that synchronization has been established. 12 is transmitted to notify 12 (S36). The synchronization establishment signal includes identification information ID of the mobile station and a synchronization establishment count value. After transmitting the synchronization establishment signal, the reception state is set in order to receive the voice signal transmitted from the mobile station 12. Thereafter, a transmission signal from the mobile station 12 is received, and if it is a voice signal, a voice call is received. Thereafter, the voice signal reception state is maintained until the voice call ends (S37 to S38). When the received signal is not a voice signal (S37-N), the process proceeds to step S39, and when the signal from the mobile station 12 does not receive an idle signal for notifying the end of the voice signal (S39-N). Then, it is determined that the voice call is likely to be continued, and the process proceeds to steps S37 to S38. However, if the idle signal is received (S39-Y), it is determined that the voice call has ended.

  When the received signal is not a communication request signal in step S31 (S31-N), the communication request signal cannot be received, or even if it can be received, synchronization cannot be established, and synchronization can be established with a subsequent audio signal Therefore, it is determined whether it is an audio signal for this purpose (S33). If the voice signal is determined, the process proceeds to step S38 to receive a voice call. If it is not an audio signal, it returns to the reception waiting state.

  Next, the flow of processing in the mobile station 12 after the end of transmission of the communication request signal (S13-Y) will be described with reference to S15 to S21. After the end of the communication request to the base station 11 (S13-Y), the mobile station 12 enters a standby state for receiving a synchronization establishment signal from the base station 11 (S15). When the synchronization establishment signal is received from the base station 11 (S16-Y), it is confirmed that the identification information ID of the own station is specified from the synchronization establishment signal, the synchronization establishment count value is extracted, and the value Is stored in the memory (not shown) of the mobile station as the new transmission count N of the communication request signal (S17), and then the voice signal is transmitted (S19). If the synchronization establishment signal from the base station 11 cannot be received (N in S16), it is determined that the synchronization is not transmitted because the base station 11 cannot establish synchronization, and the transmission request signal transmission count N is transmitted. The number of times is set to an initial value (S18). The initial value of the number of transmissions is the number of transmissions (six times in this embodiment) that can be surely synchronized stored in the memory. Thereafter, the steps S19 to S20 are repeated until the voice call (sending of the voice signal) is finished. When the voice call is finished, an idle signal for notifying the end of the voice call is set a predetermined number of times (for example, 3). Times) (S21).

  As described above, according to the present invention, the mobile station 12 adds the transmission end information so that the mobile station 12 can recognize that it is the final communication request signal in the communication request signal transmitted to the base station 11, and transmits. The base station 11 receives the communication request signal for the last time by switching to the reception state for one or a specified frame period and receiving a synchronization establishment signal (a signal notifying that synchronization has been established) from the base station 11. After that, if synchronization is established, it is possible to confirm whether synchronization has been established before shifting to the voice call by transmitting a synchronization establishment signal to the mobile station 12. There will be no situation where the head of the phone or the caller is unknown. When the mobile station 12 cannot receive the synchronization establishment signal, it is possible to perform processing such as moving to transmission of a communication request again without shifting to voice call.

  Further, according to the present invention, by adding information (transmission counter value) information for counting the number of transmissions for each transmission to the communication request signal, the base station 11 can determine the communication request signal at the time when synchronization can be established. The number of transmissions (synchronization establishment count value) is extracted, added to the synchronization establishment signal and transmitted to the mobile station 12, and the mobile station 12 that has received the synchronization establishment signal receives the communication request signal for the next call connection. Since the number of transmissions is set based on the information on the synchronization establishment count value when the call connection is made again to the base station 11 that has once established the call connection, the number of transmissions is set early. Since it is possible to confirm the establishment of synchronization, it is possible to eliminate the disadvantage that the time until the start of the call is delayed due to the transmission of an unnecessary communication request signal.

11: Base station, 12: Mobile station.

Claims (3)

A base station, and a mobile station that performs radio communication with the base station,
When the mobile station communicates with the base station, the mobile station transmits a communication request signal for synchronization with the base station for a pre-stored number of transmissions N.
The mobile station transmits the N-th communication request signal including transmission end information of the communication request signal, and then enters a reception state.
The base station receives the communication request signal, establishes synchronization, and extracts the transmission end information included in the communication request signal, a synchronization establishment signal indicating that synchronization is established for the mobile station. A wireless communication system characterized by transmitting.   The mobile station includes a transmission counter that counts the number of transmissions of the communication request signal, and transmits the communication request signal including the count value of the transmission counter and the value of the number of transmissions stored in advance. 2. The wireless communication system according to claim 1, wherein the transmission end information is transmitted when the count value matches the value of the number of transmissions stored in advance. The base station extracts, as a synchronization establishment count value, a count value of the transmission counter included in the communication request signal when the communication request signal is received and synchronized, and the synchronization establishment count value is extracted from the synchronization establishment count value. Send as a signal,
The wireless communication system according to claim 2, wherein the mobile station receives the synchronization establishment count value and stores the synchronization establishment count value as the number N of transmissions of a new communication request signal.

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