JP2001054154A - Hand-off control system by mobile station in private communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the connection time for hand-off by allowing a base station to inform a mobile station of a radio condition assigned to its own base station zone and transmitting the radio condition of its own base station zone where the mobile station is in existence to a mobile station in existence in its own base station zone and other base station zone via a communication channel. SOLUTION: A mobile station 11 in existence in a zone of a base station 1 stores a radio condition of other zone obtained from other mobile stations through group simplex communication. Thus, even when the mobile station 11 moves to a zone of a base station 2 or 3 during inter-zone simplex communication, since the mobile station 11 recognizes in advance radio conditions f34, f36, the mobile station 11 can establish synchronization with a base station to the zone of which the mobile station 11 moves without the need for redialing. Thus, it is not required to confirm the radio zone through redialing and the mobile station can make hand-off in a short time. Since utilizing the function of the mobile station makes the transmission of the radio condition, the mobile station can reduce the connection time required for the hand-off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handoff control method by a mobile station in private communication, and more particularly to a handoff control method for shortening a connection time in a recalling type handoff during simplex communication in private communication by a mobile station.

[0002]

2. Description of the Related Art A channel specifying method in a conventional mobile communication system will be described with reference to FIGS.
In the following description, the channel is expressed as ch.

FIG. 1 is an example of a configuration diagram of a mobile communication system, and FIG. 8 is a flowchart showing a state transition in a mobile station in a conventional recalling type handoff in the system of FIG.

The channel designation message broadcast by the base station 1 broadcasts only the radio conditions used by the mobile stations 11 to 13 existing in the base station 1. The wireless receiving unit 54 in FIG.
Processes the received channel designation message in the control unit 59, and determines the communication channel (T_c in FIG. 8) allocated for communication.
The control unit 59 that has recognized h) issues a change instruction to the wireless transmission unit 53 and the wireless reception unit 54. The wireless transmission unit 53 and the wireless reception unit 54 control the designated communication channel by the control channel (C in FIG. 8).
_Ch) to establish synchronization and enter a communication state.

When the mobile station 11 moves during the group simplex communication and changes the communication zone, the reception level is detected by the radio reception section 54, and the level is detected by the level determination section 55 as level deterioration. At this time, the control section 59 searches for the frequency level of the control channel of the preset peripheral zone, and transmits the search result to the control section 59. The control unit 59 can determine which base station zone has been moved based on the search result. The control unit 59 recognizing the movement destination zone transmits the radio transmission unit 53 and the radio reception unit 5 to the control channel of the base station 2 which is the movement destination.
The frequency setting of No. 4 is switched.

The radio receiving unit 54 synchronizes with the control channel of the base station 2, collects information reported by the control channel of the base station 2, and transmits the information to the control unit 59. Then, the control unit 59 that has analyzed the information
Transmits a request message to the wireless transmission unit 53 in order to confirm the wireless conditions during which the group of the mobile stations 11 are communicating within the base station 2 to the wireless transmission unit 53. Then, the channel designation message request transmitted from the wireless transmission unit 53 is processed by the control station 100 via the base station 2 and is again transmitted from the base station 2 to the mobile station 11 as a channel designation message.

[0007] The mobile station 11 processes the channel designation message received by the radio receiving section 54 at the control section 59. The control unit 59 that has recognized the communication channel allocated for communication in the base station 2 issues a frequency change instruction to the wireless transmission unit 53 and the wireless reception unit 54. Then, the wireless transmission unit 53 and the wireless reception unit 5
4 switches from the control channel to the designated communication channel, establishes synchronization, and enters a communication state.

[0008]

However, in the above-mentioned conventional system, the mobile station needs to make a call again in order to confirm the radio conditions of the destination base station to the control station or the like. For this reason, when a mobile station in a communication state moves between zones, there occurs a problem that a handover time of communication returning to group simplex communication, that is, a so-called handoff time becomes longer.

[0009] The present invention has been made in view of such circumstances, and has as its object the purpose of not switching between a control channel and a communication channel when a mobile station moves to another base station zone. An object of the present invention is to shorten the connection time in handoff by directly establishing synchronization in a communication channel and entering a communication state.

It is another object of the present invention to provide a mobile station having means for shortening a connection time in handoff.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a system for enabling a handoff during a simplex communication in a private communication from a base station to a mobile station. When the mobile station having the transmission right performs the group simplex communication, the mobile station having the transmission right performs the wireless condition of the base station zone where the mobile station is located. By transmitting to the other mobile stations existing in the zone and the other base station zone, when the mobile station moves to the other base station zone during the inter-zone simplex communication, without performing the handoff process in the control channel, directly, The communication channel is handed off. Thus, when the mobile station moves to another base station zone, synchronization can be established in the communication channel, so that a communication state can be entered in a short time.

The wireless condition is information necessary for performing communication, such as a frequency code, a scramble pattern, a slot number (for a TDMA system), and a call number of a communication channel.

In other words, the handoff control method by the mobile station in the private communication according to the present invention is a handoff control method for a system in which the handoff can be performed during the simplex communication in the private communication. Before the start of communication, the mobile station notifies the mobile station of a radio condition assigned to the own base station zone of the communication channel via a control channel by a channel designation message, and the mobile station having a transmission right performs group simplex communication. When performing, the wireless condition of the own base station zone in which the mobile station is present is transmitted to other mobile stations present in the own base station zone and other base station zones via a communication channel, and the other mobile station transmits the wireless condition. When the mobile station moves to another base station zone during the simplex communication between zones, the mobile station of the other base station zone that has been recognized in advance is stored. Based on the matter, characterized in that handoff in synchronization with the communication channel of the moved the other base station.

The radio conditions include at least a base station number, a communication channel frequency code, a scramble pattern, a slot number in the case of a TDMA system, a call number assigned to a call in base station units, and It is characterized by being information necessary for performing communication on a communication channel including a calling mobile station number when transmitting from a mobile station.

Further, the mobile station includes a transmitting / receiving antenna for transmitting / receiving radio waves to / from the base station, a duplexer for controlling switching between transmitted and received waves, a radio transmitting unit for transmitting transmission data, A radio reception unit for receiving, a level determination unit for analyzing a reception level, a scramble processing unit for descrambling received data, a processing unit for a voice mode and a processing unit for a non-voice mode for processing an output of the scramble processing unit; A control unit that creates and analyzes transmission / reception data and controls each unit, a memory unit that temporarily stores data received and analyzed by the control unit, and outputs audio data processed by the audio mode processing unit. A mobile communication system comprising a voice output unit, wherein the mobile station can switch between a non-voice mode and a voice mode, and cannot switch between a non-voice mode and a voice mode Characterized in that that can be applied to both of the moving body communication system.

When the mobile station performs group simplex communication, the mobile station acquires the transmission right and transmits the radio conditions assigned by the base station in a non-voice mode to another mobile station for a certain period of time. Then, the mobile station transmits a mode change instruction message from the non-voice mode to the voice mode, transmits voice data in the voice mode, and the mobile station that has completed necessary communication releases the transmission right, It is characterized by the following.

Further, when the mobile station performs group simplex communication and receives received data,
When the mobile station is applied to a mobile communication system capable of switching between a non-voice mode and a voice mode, the radio reception unit that has received the reception data sends the reception data to the scramble processing unit, and the scramble is performed. Descramble the scramble determined by the processing unit and send it to the control unit, the control unit recognizes a mode change instruction, and the control unit determines whether the received data after recognition is in a non-voice mode or a voice mode, The non-voice mode processing unit or the voice mode processing unit instructs the reception data to be processed by an appropriate processing unit, and the reception data is processed by the non-voice mode processing unit. In the case, the wireless condition is extracted from the received data and stored in the memory unit, and if the received data is processed by the voice mode processing unit, From the received data by extracting the audio data and outputs from the audio output unit.

Further, when the mobile station performs group simplex communication and receives received data, the mobile station is connected to a mobile communication system that cannot switch between the non-voice mode and the voice mode. When applied, the wireless receiving unit receiving the received data stores the received data in the wireless receiving unit, descrambles the data in the scramble processing unit, and then creates two pieces of descrambled data. Then, each of the non-voice mode processing unit and the voice mode processing unit is processed, and when the data is normally processed by the non-voice mode processing unit, the wireless condition is extracted from the received data to extract the wireless condition. When the data is stored and stored in the memory unit and the data is normally processed by the audio mode processing unit, the audio data is extracted from the received data and the audio data is extracted from the audio output unit. Output, characterized in that.

Further, when the radio receiving section receives the channel designation message, the mobile station sends the received data to the control section via the scramble processing section and the non-voice mode processing section, and the control section Analyzing the channel designation message, confirming the radio condition assigned to the base station where the mobile station is located, issuing an instruction to the radio transmitting unit and the radio receiving unit, and synchronizing with the given radio condition. Control to be in an established / communication state, the memory unit stores the wireless condition of the own base station zone, and when communication between the mobile station and another mobile station is started, the other mobile station The wireless receiving unit receives data of the assigned wireless condition, the received data is descrambled by the scramble processing unit, and after being processed by the non-voice mode processing unit, The control unit recognizes the wireless condition of the other base station zone and stores it in the memory unit.If the mobile station moves during the group simplex communication and changes the communication zone, the wireless receiving unit changes the reception level. The level determination unit detects the reception level as level deterioration, further searches for a preset control channel frequency level of another base station zone, and transmits a search result to the control unit. The control unit determines a destination base station zone of the mobile station based on a search result, and the control unit that recognizes the destination base station zone communicates with the memory unit when communicating in the destination base station zone. Confirming the radio conditions, issuing an instruction to the radio transmitting unit and the radio receiving unit based on the confirmed radio conditions, and performing communication in the base station zone after the movement from the communication channel in the base station zone before the movement of the mobile station; Performing control so to become synchronization establishment and communication state change to Yaneru, characterized in that.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 1, according to the present invention, in the mobile stations 11 to 17 receiving the channel designation message broadcast from the base stations 1, 2, and 3, when the mobile station having the transmission right starts communication, the mobile station starts communication. Ch previously notified by the base station
It is characterized in that the contents of the radio conditions assigned to the own zone in the designated message are transmitted to another mobile station. Here, the channel designation messages broadcast from the base stations 1, 2, and 3 are broadcast via control channels f31, f33, and f35, the communication channel in the base station 1 is f32, and the communication channel in the base station 2 is f32. Is f34, and the communication channel in the base station 3 is f34.
36.

The mobile station 11 existing in the base station 1 holds the radio conditions of another zone obtained from another mobile station by the group simplex communication, so that the mobile station 11 Even when moving to the station 2 or the base station 3 between zones, since the radio conditions of f34 and f36 in FIG. 1 are recognized in advance, synchronization can be established at the moved base station without recalling.

Therefore, there is no need to confirm the wireless condition by re-calling, and the effect that handoff can be performed in a short time is obtained. In addition, since the transmission of the wireless condition is performed by using the function of the mobile station, an effect is obtained that the connection time in handoff can be shortened by the mobile station.

FIG. 2 is a simplified flowchart from transmission of a connection request to transmission of wireless conditions in the system shown in FIG. That is, in FIG. 2, the mobile station 11 existing in the base station 1 enters the communication state after transmitting the inter-zone simplex communication request, and the mobile station 11 having the transmission right is
The flow of processing from communication to the mobile station 17 to transmission of the wireless condition of the communication channel in the own station zone is shown. Also,
FIG. 3 shows a communication channel notified by a mobile station to another mobile station.
5 is a structural example of the wireless condition. FIG. 4 is a flowchart of wireless condition transmission in a mobile communication system capable of mode switching. That is, FIG.
In the access permission state of (13), after the mobile station acquires the transmission right and then transmits the radio conditions to other mobile stations, the mode is switched from a data signal to a voice signal by mode switching. It is a flowchart until it becomes a talking state and performs transmission right release. FIG. 5 is a flowchart of wireless condition transmission in a mobile communication system in which mode switching cannot be performed. That is, in the access permission state of (13) in FIG. 2, the flowchart is from when the mobile station acquires the transmission right to when the wireless condition is transmitted to other mobile stations and the transmission right is released. FIG. 6 is a diagram showing a configuration inside the mobile station in the system of FIG. FIG. 7 is a flowchart showing a state transition inside the mobile station of FIG.

First, the configuration of the system shown in FIG. 1 will be described.
The base station 1 has a frequency f3 assigned to the base station 1.
A wireless communication zone 41 is formed by 1 · f32 and the like. Similarly, the base station 2 / base station 3 form a wireless communication zone 42 / wireless communication zone 43 with frequencies f33 / f34 / f35 / f36 and the like, respectively.

Here, the mobile stations 11 to 17 are in the same group, the mobile stations 11 to 13 are registered in the zone of the base station 1, and the mobile stations 14 to 16 are registered in the zone of the base station 2. The mobile station 17 has registered in the zone of the base station 3. Also, base station 1, base station 2, base station 3
Are controlled by the control station 100 via the control line 21, the control line 22, and the control line 23, respectively. Further, communication ch_f32 / f34 / f is transmitted between the mobile stations 11 to 17.
36, the mobile station 1 is in the simplex communication state between zones.
1 shows a state where the mobile phone 1 has moved from the wireless communication zone 41 to the wireless communication zone 42 in a call state.

Next, the operation of the embodiment of the present invention will be described.

FIG. 2 shows that the mobile station 11 requests the base station 1 for group simplex communication between the mobile stations 11 to 17.
FIG. 2 shows a flow until a communication state is established.
The messages (1) to (27) shown in FIG.
There are sequences such as NACK and confirmation of radio resources,
In this flowchart, only the contents of messages necessary for implementing the present invention will be described.

(1) in FIG. 2 is a connection request signal for group simplex communication between the mobile station 11 and the mobile station 17 from the mobile station 11 to the base station 1. The mobile station 11 is (1)
Is transmitted on the control channel at f31. In (2), the connection request signal is transferred from the radio unit to the control unit inside the base station 1 and transmitted. (3) is a connection request signal transmitted from the control unit of the base station 1 to the control station 100 via the control line 21.

Next, a base station zone in which the group of the mobile station 11 is registered is selected in the control station 100, and a channel designation message signal of each base station is sent to the registered base stations 1 to 3. Data is transmitted to the control unit via the control lines 21 to 23 ((4), (6), (5)). In addition, each channel designation message signal (4), (6), (5)
Includes all the radio conditions of the communication channels transmitted by each base station.

(7) is a transfer signal from the control unit to the wireless unit of the message (ch designation message) of (4) in the base station 1.

Similarly, (11) and (9) are equivalent to (6)
This is a relocation signal in the base station 2 and the base station 3 of (5). (8) is a channel designation message transmitted to the mobile stations 11 to 13 by the control channel_f31 of the base station 1. This includes the communication channel (f32) of the base station 1.
Wireless conditions are included.

Similarly, (12) and (10) correspond to the base station 2
-Mobile stations 14 to which base station 3 is registered in its own zone
This is a channel designation message to the mobile station 16 and the mobile station 17, and notifies the wireless condition of the communication channel of the own station.

(13), (15), and (14) show a state in which an access waiting signal from a mobile station is transmitted to the entire zone in a communication channel assigned by each base station.

In (16), the mobile station 11 communicates with the base station 1 using the communication channel ch_f32 according to the assigned radio conditions. At that time, the assigned wireless condition is included in the communication. In (17), it is reloaded in the base station 1, and (1)
The data is transmitted to the control station 100 in 8). (19) ・ (21)
-The base station 1 and the base station 2 from the control station 100 by (20)
And the communication channel (f32) of each base station.
· F34 and f36), (22) · (26) ·
(24) and the mobile station 11 to the mobile station 12 to the mobile station 17 existing in the base station via (23), (27), and (25).
The transmission data of arrives. The mobile stations 12 to 17 take out and store the wireless conditions of the communication channel f_32 of the base station 1 where the mobile station 11 is located. When the mobile stations 12 to 17 perform communication, the communication c similarly allocated from the base station.
h is included in the communication.

FIGS. 3, 4, and 5 show the above-mentioned (16) to (27) in more detail.

First, the communication channel transmitted in (16) of FIG.
3 will be described in detail with reference to FIG.

Six octets, octet 1 to octet 6, store the radio conditions of the communication channel allocated by the base station 1. Octet 1 stores the base station number. In FIG. 3, the system code of the base station 1 is used. Octet 2 stores the frequency code of the communication channel. Octet 3 stores a scramble pattern. Octet 4 stores the slot number. This is FDM
A (frequency multiplexing multi)
ple access (frequency division multiple access) system is not required, but TDMA (time division)
This is because in a system of the "sion multiple access (time division multiple access)" system, since the frequency is multiplexed, it is necessary to recognize the used slot number.

Octet 5 stores the call number assigned by the base station. This is because the call number is arbitrarily assigned by each base station, so that the call number is different depending on the base station even if the call is for the same inter-zone communication. Octet 6 stores the originating mobile station number.

The mobile station communicates with the communication c assigned by the base station.
When transmitting the wireless condition of h, since this information is data, FACCH (fast as
associated control channel:
High-speed associated control channel and SACCH (slow as
associated control channel:
Transmission is performed using a non-voice mode such as a low-speed associated control channel. On the other hand, when performing voice communication, transmission is performed using a TCH (traffic channel), which is a voice mode.

In various mobile communication systems, there are a system that can switch between the non-voice mode and the voice mode within the same transmission right, and a system that cannot switch between the non-voice mode and the voice mode.

Next, referring to FIG. 4, the operation of the system capable of mode switching will be described.

In FIG. 4, after acquiring the transmission right, the mobile station 11 transmits the radio conditions of the communication ch_f32 assigned by the base station 1 in the non-voice mode to the mobile stations 12 to 17 for a certain period of time. Thereafter, the mobile station 11 transmits a mode change instruction message from the non-voice mode to the voice mode, and transmits voice data in the voice mode. The mobile station 11 that has completed the necessary communication releases the transmission right. In FIG. 4, after that, the mobile station 17 secures the transmission right and transmits the radio conditions of the communication ch_f36 allocated from the base station 3 in the non-voice mode to the mobile stations 11 to 16, and then switches to the voice mode to perform voice communication. I do.

Next, the internal operation of the mobile station when the operation shown in FIG. 4 is performed will be described with reference to FIG.

FIG. 6 is a diagram showing a configuration inside the mobile station in the system of FIG.

In FIG. 6, a mobile station includes a transmission / reception antenna 51 for transmitting / receiving radio waves to / from a base station, a duplexer 52 for controlling transmission / reception wave switching, and radio transmission for transmitting transmission data. Unit 53, a wireless reception unit 54 for receiving reception data, and a level determination unit 5 for analyzing a reception level
5, a scramble processing unit 56 for descrambling received data, an audio mode processing unit 57 for processing the output of the scramble processing unit 56, and a non-audio mode processing unit 58
And a control unit 59 for creating and analyzing transmission / reception data and controlling each unit, a memory unit 60 for temporarily storing data received and analyzed by the control unit, and audio data processed by the audio mode processing unit 57. Is output from the audio output unit 61.

The internal operation of the mobile station when the operation shown in FIG. 4 is performed will be described. The radio receiving unit 54 which has received the received data descrambles the predetermined scramble in the scramble processing unit 56 and sends the mode change instruction to the control unit. 59 recognizes. The control unit 59 determines whether the received data after the recognition is in the non-voice mode or the voice mode, and processes the received data to the non-voice mode processing unit 58 or the voice mode processing unit 57 by an appropriate processing unit. To instruct.

When the received data is processed by the non-voice mode processing unit, the wireless condition is extracted from the received data and stored in the memory unit, and the received data is processed by the voice mode processing unit. In this case, audio data is extracted from the received data and output from the audio output unit. Next, the transmission operation of wireless conditions in a system in which mode switching is not performed will be described with reference to FIG.

In FIG. 5, the mobile station 1 that has acquired the transmission right
Numeral 1 transmits the wireless condition of the communication channel ch_f32 assigned from the base station 1 in the non-voice mode to the mobile stations 12 to 17 for a certain period of time.

Since the mobile station 12 to the mobile station 17 do not know whether the mode of the received data is non-voice or voice, after storing the received data in the radio receiving unit 54 of FIG. 6, the scramble processing unit 56 descrambles the received data. Thereafter, two pieces of descrambled data are created, and the non-voice mode processing unit 58 is used.
And the voice mode processing unit 57 respectively. Since the data transmitted first from the mobile station 11 is data in a non-voice mode for notifying wireless conditions, the voice-mode processing unit 57 cannot properly process the received data and discards it.
On the other hand, the non-voice mode processing unit 58 normally processes data and recognizes the wireless condition of the communication channel ch_f32.
9 stores the wireless condition in the memory unit 60.

[0051] The mobile station 11 keeps the communication ch_f32 for a certain period of time.
If the mode is changed to the voice mode at an arbitrary timing after the transmission of the wireless condition and the voice communication is started, the mobile station 12
After the mobile station 17 stores the received data in the wireless reception unit 54 of FIG. 6, the mobile station 17 descrambles the data in the scramble processing unit 56. Thereafter, two pieces of descrambled data are created, and the non-voice mode processing unit 58 and the voice mode processing unit 5
The processing is performed in step S7. Since the data transmitted from the mobile station 11 is data in the voice mode, the non-voice mode processing unit 58 cannot process the data normally and discards the data. The received data processed by the audio mode processing unit 57 is processed by the audio output unit 61 as received audio. The mobile station 11 releases the transmission right when the transmission of the required voice communication is completed.

In FIG. 5, after the mobile station 11 releases the transmission right, the mobile station 17 acquires the transmission right and the radio conditions of the communication ch_f 36 assigned by the base station 3 are changed to the mobile stations 11 to 1.
6 is described.

Next, the flow of processing when a mobile station recognizing the radio conditions of another zone performs handoff will be described with reference to FIG. 6 and FIG.

FIG. 7 is a flowchart showing a state transition inside the mobile station of FIG. 6, and is a flowchart showing an operation inside the mobile station when the mobile station 11 performs a handoff during the group simplex communication.

The mobile station 11 receives the channel designation message from the base station 1 and, after confirming the radio conditions to be used as the communication channel (T_ch in FIG. 7), the control unit 59
3 and an instruction to switch from the control channel (C_ch in FIG. 7) to the communication channel to the wireless receiving unit 54, and the memory unit 60
The wireless condition of the communication channel of the own zone is stored in advance.

The wireless receiving section 54 enters the synchronization established / communication state under the wireless conditions instructed by the control section 59. When communication with another mobile station is started, the wireless receiving unit 54 receives data on wireless conditions to which another mobile station is assigned. After the received data is descrambled by the scramble processing unit 56 and processed by the non-voice mode processing unit 58, the control unit 59 recognizes the wireless condition of the other zone. The wireless conditions of the communication channel of each base station recognized in this way are stored in the memory unit 60.

Thereafter, when the mobile station 11 moves during the group simplex communication and changes the communication zone, the reception level is detected by the radio reception section 54, and the level is detected as level deterioration by the level determination section 55. At this time, the frequency level of the control channel of another zone set in advance is searched,
The search result is transmitted to the control unit 59. The control unit 59 can determine which base station zone has been moved based on the search result. The control unit 59 recognizing the destination zone checks the wireless condition for communication in the destination zone with respect to the memory unit 60. The wireless transmission unit 53 and the wireless reception unit 5
4, the communication channel of the zone before the movement is changed to the communication channel of the new zone, and control is performed such that the synchronization is established and the communication state is established.

The embodiment described above is an example for describing the present invention, and the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the invention. is there. For example, although the basic configuration is the same as that of the above-described embodiment, the management of the communication state by the control station 100 as the system configuration example of FIG. It is needless to say that the present invention can be applied even if the system configuration is such that the communication station 3 manages the communication state and the control station 100 only manages the wired connection lines with the base station 1, the base station 2, and the base station 3. Absent.

In the above-described embodiment, the control channel and the communication channel are described as different frequencies. However, the TDM (time dime) for allocating the control channel and the communication channel at the same frequency is described.
The present invention is also applicable to a system of a vision multiplex (time division multiplex) system.

[0060]

As described above, according to the present invention,
The connection / confirmation time due to re-calling can be saved. For this reason, even if the mobile station moves to another base station zone in the communication state, the communication state can be returned to the communication state in a shorter time than before.

Further, the shortening of the connection time in the handoff can be realized only by the function of the mobile station, and the mobile station of the present invention is a mobile communication system that can switch between the non-voice mode and the voice mode. Applicable to both body communication systems.

Further, it is possible to reduce the traffic of the control channel for the infrastructure equipment including the base station.

[Brief description of the drawings]

FIG. 1 is an example of a configuration diagram of a mobile communication system.

FIG. 2 is a simplified flowchart from transmission of a connection request to transmission of wireless conditions in the system shown in FIG. 1;

FIG. 3 shows a communication channel notified by a mobile station to another mobile station.
5 is a structural example of the wireless condition.

FIG. 4 is a flowchart of wireless condition transmission in a mobile communication system capable of performing mode switching.

FIG. 5 is a flowchart of wireless condition transmission in a mobile communication system in which mode switching cannot be performed.

FIG. 6 is a diagram showing a configuration inside a mobile station in the system of FIG. 1;

FIG. 7 is a flowchart showing a state transition inside the mobile station of FIG. 6;

FIG. 8 is a flowchart showing a state transition in a mobile station in a conventional recalling type handoff.

[Explanation of symbols]

 1, 2, 3 Base station 11, 12, 13, 14, 15, 16, 17 Mobile station 21, 22, 23 Control line f31, f33, f35 Control channel f32, f34, f36 Communication channel 41, 42, 43 Wireless communication Zone 100 Control station 51 Transmission / reception antenna 52 Duplexer 53 Radio transmission unit 54 Radio reception unit 55 Level determination unit 56 Scramble processing unit 57 Processing unit for voice mode 58 Processing unit for non-voice mode 59 Control unit 60 Memory unit 61 Voice output unit

Claims (7)

[Claims] 1. In a handoff control method for a system that enables a handoff to be performed during a simplex communication in a private communication, each base station transmits to a local base station zone of a communication channel before starting communication of a mobile station. The assigned radio conditions are reported to the mobile station via a control channel in a channel designation message, and when the mobile station having transmission right performs group simplex communication, the mobile station in the base station zone where the mobile station is located The wireless condition is transmitted to other mobile stations existing in the own base station zone and the other base station zone via a communication channel, the other mobile station stores and holds the wireless condition, and the mobile station performs inter-zone simplex. When moving to another base station zone during communication, handover is performed in synchronization with the communication channel of the moved other base station based on the radio conditions of the other base station zone recognized in advance. A handoff control method by a mobile station in private communication, characterized in that: 2. The radio conditions include at least a base station number, a communication channel frequency code, a scramble pattern, a slot number in the case of a TDMA system,
2. The information according to claim 1, wherein the information is necessary for performing communication on a communication channel including a call number assigned to a call on a base station basis and a calling mobile station number when transmitting from a mobile station. A handoff control method by a mobile station in the private communication described in the above. 3. The mobile station includes: a transmitting / receiving antenna for transmitting / receiving radio waves to / from a base station; a duplexer for controlling switching between transmission waves and reception waves; a radio transmission unit for transmitting transmission data; A radio reception unit for receiving, a level determination unit for analyzing a reception level, a scramble processing unit for descrambling received data, a processing unit for a voice mode and a processing unit for a non-voice mode for processing an output of the scramble processing unit; A control unit that creates and analyzes transmission / reception data and controls each unit, a memory unit that temporarily stores data received and analyzed by the control unit, and outputs audio data processed by the audio mode processing unit. A mobile communication system comprising a voice output unit, wherein the mobile station can switch between a non-voice mode and a voice mode, and a mobile communication system which cannot switch between a non-voice mode and a voice mode. 3. A handoff control method by a mobile station in private communication according to claim 1, wherein the handoff control method can be applied to both communication systems. 4. When the mobile station performs group simplex communication, the mobile station acquires the right to transmit and transmits the radio conditions assigned by the base station in a non-voice mode to another mobile station for a certain period of time. Then, the mobile station transmits a mode change instruction message from the non-voice mode to the voice mode, transmits voice data in the voice mode, and the mobile station that has completed necessary communication releases the transmission right, 4. The handoff control method by a mobile station in private communication according to claim 1, wherein 5. When the mobile station performs group simplex communication and receives received data, the mobile station is applied to a mobile communication system capable of switching between a non-voice mode and a voice mode. If the received data is received, the wireless receiving unit sends the received data to the scramble processing unit, descrambles the scrambled data by the scramble processing unit, and sends it to the control unit. Recognizes a mode change instruction, the control unit determines whether the received data after recognition is a non-voice mode or a voice mode, and sends the received data to the non-voice mode processing unit or the voice mode processing unit. And instructing the appropriate processing unit to process, and if the received data is processed by the non-voice mode processing unit, extract the wireless condition from the received data. Then, when the received data is processed by the audio mode processing unit, the audio data is extracted from the received data and output from the audio output unit. Claim 1
5. A handoff control method by a mobile station in private communication according to claim 4. 6. A mobile communication system in which the mobile station performs group simplex communication and receives received data, wherein the mobile station cannot switch between a non-voice mode and a voice mode. When applied, the wireless receiving unit receiving the received data stores the received data in the wireless receiving unit, descrambles the data in the scramble processing unit, and then creates two pieces of descrambled data. Then, each of the non-voice mode processing unit and the voice mode processing unit is processed, and when the data is normally processed by the non-voice mode processing unit, the wireless condition is extracted from the received data to extract the wireless condition. Store in the memory section,
The method according to claim 1, wherein when the data is normally processed by the voice mode processing unit, the voice data is extracted from the received data and output from the voice output unit. Handoff control method by mobile station in private communication. 7. The mobile station, when the channel receiving message is received by the radio receiving unit, received data is sent to the control unit via the scramble processing unit and the non-voice mode processing unit, and the control unit Analyzing the channel designation message, confirming the radio condition assigned to the base station where the mobile station is located, issuing an instruction to the radio transmitting unit and the radio receiving unit, and synchronizing with the given radio condition. Control to be in an established / communication state, wherein the memory unit is
The wireless condition of the own base station zone is stored, and when communication between the mobile station and another mobile station is started, the wireless receiving unit receives data of the wireless condition to which the other mobile station is assigned. The received data is descrambled by the scramble processing unit, and after being processed by the non-voice mode processing unit, the control unit recognizes a radio condition of another base station zone and stores it in the memory unit, When the mobile station moves during the group simplex communication and changes the communication zone, the radio receiving unit detects a reception level, and the level determination unit detects the reception level as level deterioration, and further sets in advance. A search is made for the frequency level of the control channel of the other base station zone, and a search result is transmitted to the control unit. Based on the search result, the control unit determines the destination base station zone of the mobile station. The controller recognizing the destination base station zone checks radio conditions for communication in the destination base station zone with respect to the memory unit, and based on the confirmed radio conditions, the radio transmitter and the radio Give instructions to the receiver,
2. The communication system according to claim 1, wherein a communication channel of the base station zone before the movement of the mobile station is changed to a communication channel of the base station zone after the movement, and control is performed such that synchronization is established and a communication state is established. 7. A handoff control method by a mobile station in the private communication according to 6.