JP2002094606A - Communication terminal, device and automatic setting method for transmission timing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic setting method wherein a transmission timing to a base station can be automatically adjusted, the installation construction work of a terminal can be performed easily, the reexamination of the setting of the terminal to be executed whenever the number of base stations is increased can be eliminated, and the concentration of a traffic operation can be improved. SOLUTION: In a fixed subscriber terminal device 104 which is applied to a WLL system using a TDMA system or a TDD duplex operating system, the electric field strength of a reception from the base station 103 is detected by a radio part 110. In a control unit 112, the initial value of the transmission timing is decided according to the electric field strength of the reception, the transmission timing which is communicable with the base station 103 is retrieved while the transmission timing is being deviated from the initial value, and the retrieved transmission timing is stored and set in a data storage part 114 as a nonvolatile memory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TDMA (Time Division M) for realizing a communication network with a semi-fixed radio network.
ultiple Access) or TDD (Time Division Duple)
x) is applied to a WLL (Wireless Local Loop) system using the duplexing method, and a system that automatically adjusts its transmission timing so that a terminal device far away from the base station matches the reception timing at which the base station waits. A communication terminal device and a transmission timing automatic device that are applied to a system that can automatically correct the transmission timing of a terminal device even when a service is started once and a new base station is added. Regarding the setting method.

[0002]

2. Description of the Related Art Conventionally, this type of communication terminal apparatus and transmission timing automatic setting method are disclosed in Japanese Patent Application Laid-Open No. 9-55979.
Is described in Japanese Patent Application Publication No.

FIG. 8 is a conceptual diagram of a WLL system.

[0004] The WLL system 800 shown in FIG.
Existing base station 802 and new base station 803 converged by base station concentrator 801 and terminal station (fixed subscriber terminal apparatus)
804 and 805.

[0005] However, the terminal station 804 is arranged at a position close to the existing base station 802, and the terminal device 705 is located in the existing base station 8
02 is located far from the newly installed base station 803.

[0006] When multiplexing or duplexing of channels is performed by time division, the time slots that can be used are limited in order to prevent interference with other channels. Therefore, when transmitting from the terminal stations 804 and 805, the base station 7
It must be transmitted in accordance with 02,803 receivable slots.

[0007] A terminal station 804 close to the base station 802 may transmit the signal in a predetermined time slot without worrying about the propagation delay of the transmission signal, but a terminal station 805 far from the base station 802 may transmit the signal. In consideration of the propagation delay, it is necessary to correct the delay of the propagation delay from the original timing and transmit the signal earlier.

[0008] However, the base stations 802 and 803 are frame-synchronized, and the system is configured so that there is no collision of a downlink broadcast signal due to a common channel.

In the prior art, if the locations where the terminal stations 804 and 805 are to be installed are determined, the locations of the base stations 80 and 805 are determined.
The propagation delay time was calculated from the distance up to 2,803, and the propagation delay time was corrected in advance so that the terminal stations 804 and 805 could remember the timing of the early delivery, so that the propagation delay time could be corrected. .

[0010]

However, the conventional WLL system has the following problems.

1. At the time of installation work of a terminal device, it is necessary for an installer to measure a distance from a desired base station, correct an optimal propagation delay time for each installation location, and store the correction in the terminal device in advance. Therefore, there is a problem that the construction is complicated.
Further, if an erroneous correction time is set due to a work error of a construction worker, there is a problem that location registration cannot be performed even if a base station signal is received.

2. If a base station is added later, there is a case where it is necessary to change the propagation delay correction value of the installed terminal device in order to perform location registration with the newly installed base station.
Each time a base station is added, it is necessary to review the settings of the terminal device, which causes a problem that the construction becomes complicated.

3. When traffic concentrates on a specific base station, even if an attempt is made to access another base station, if the transmission timing of the terminal device is not appropriate, access cannot be made and the concentration of traffic cannot be improved. is there.

The present invention has been made in view of the above points, and enables automatic adjustment of transmission timing to a base station, thereby facilitating terminal installation work, and An object of the present invention is to provide a communication terminal device and a transmission timing automatic setting method that can eliminate the review of terminal settings performed each time an extension is performed and can improve the concentration of traffic.

[0015]

According to the present invention, there is provided a communication terminal apparatus, in a WLL system, a means for determining an initial value of a transmission timing according to a received electric field strength from a base station apparatus; A configuration is provided that includes means for searching for a transmission timing at which communication with the base station device is possible while shifting the transmission timing, and means for setting the searched transmission timing.

[0016] According to this configuration, the transmission timing to the base station device can be automatically adjusted, whereby the installation work of the communication terminal device can be easily performed. Since only two signals of transmission timing search, that is, a link channel establishment request from the communication terminal device and a link channel assignment from the base station device in response to this request are used, only the base station device and the communication terminal device need to use only two signals. The transmission timing setting can be completed, so that the traffic of the entire system is not significantly affected. Since the timing adjustment is started by associating the reception field strength with the initial value for setting the transmission timing, the transmission timing adjustment time can be reduced.

The communication terminal apparatus according to the present invention employs a configuration in which the transmission timing is set at the time of a request for establishing a link channel at the time of initial location registration immediately after power-on.

According to this configuration, the transmission timing to the base station device can be automatically adjusted at the time of the first location registration immediately after the power is turned on.

The communication terminal apparatus of the present invention employs a configuration in which the transmission timing is set at the time of searching for a new candidate base station apparatus that satisfies the reception electric field strength.

According to this configuration, when a new candidate base station device is found, the transmission timing to the base station device can be automatically adjusted.

In the above configuration, the communication terminal apparatus of the present invention, when the base station apparatus does not respond to the link channel establishment request at the time of location registration, even though the received electric field strength is higher than a predetermined value, A configuration to search and set the transmission timing is adopted.

According to this configuration, when there is no response from the base station apparatus to the link channel establishment request, and when the received electric field strength from the base station apparatus is high, the transmission timing to the base station apparatus is changed. Can be adjusted automatically.

In the communication terminal device according to the above-mentioned configuration, when setting the searched transmission timing, the transmission timing is associated with the unique information of the base station device relating to the transmission timing in the nonvolatile storage means. Take a configuration to memorize.

According to this configuration, the optimum transmission timing is stored in the communication terminal device, and can be used for the position registration at the next power-on. The startup operation after turning on the power can be performed quickly.

In the above configuration, the communication terminal device of the present invention, in the above configuration, periodically searches for a received electric field intensity from a peripheral base station device after completion of the location registration, and if the searched electric field intensity exceeds a predetermined value and When the unique information of the base station device of the electric field strength is other than the unique information stored in the non-volatile storage means, a link channel establishment request is made, and when the request is responded to, the transmission timing at this time is determined by the base station device. Is stored in the non-volatile storage means in association with the unique information.

According to this configuration, even after the location registration is completed, the transmission timing to another communicable base station can be found and set. Even after the completion of the position registration, the search for the peripheral base station device is continuously performed, so that it is not necessary to change the transmission timing setting of the communication terminal device every time the base station device is added.

The communication terminal apparatus of the present invention employs a configuration in which, in the above configuration, when a plurality of pieces of unique information are stored in the non-volatile storage means, the location registration of the unique information having a high received electric field strength is performed to the base station apparatus.

According to this configuration, even after the location registration is completed, it is possible to perform communication with the base station apparatus having the optimum communication state.

The communication terminal apparatus of the present invention employs a configuration in which, in the above configuration, when a plurality of pieces of unique information are stored in the non-volatile storage means, the location registration of the unique information having a low received electric field strength is performed to the base station apparatus.

According to this configuration, it is possible to communicate with a communicable base station.

In the communication terminal device according to the above configuration, when an incoming / outgoing call is detected during the search for the received electric field strength from the peripheral base station device, the search is stopped, and the process of the incoming / outgoing call is given priority. Is adopted.

According to this configuration, if there is an outgoing / incoming call during the transmission timing adjustment after the location registration, the outgoing / incoming call is prioritized, so that the dropped outgoing / incoming call can be reduced.

In the above configuration, the communication terminal apparatus of the present invention waits for a link channel allocation request from the peripheral base station apparatus so as not to lose the incoming call when searching for the received electric field strength from the peripheral base station apparatus. A configuration for simultaneously receiving a paging channel is employed.

According to this configuration, even if there is an incoming call during the transmission timing adjustment after the location registration, it is possible to search for the peripheral base station device.

The communication terminal apparatus according to the present invention, in the above-mentioned configuration, has a configuration in which the relation between the transmission timing and the reception electric field strength is tabulated and stored, and means for connecting an external device for changing the stored transmission timing is provided. take.

According to this configuration, the transmission timing can be arbitrarily changed from outside.

[0037] The communication terminal apparatus of the present invention employs, in the above-described configuration, means for correcting a table storage value in accordance with a unique information signal of the base station apparatus when the received field strength stored in the table is different. .

According to this configuration, the information value stored in the table can be made an appropriate value.

According to the communication terminal apparatus of the present invention, in the above configuration, when the transmission timing from the external device is changed, the transmission timing is shifted forward and backward around the standard transmission timing.
A configuration is adopted in which a movement can be made for each ΔX symbol within the range of X symbols.

According to this configuration, the transmission timing can be appropriately changed from outside.

In the above configuration, when the communication terminal device issues a link channel establishment request during the transmission timing search, the communication terminal device determines whether the request is a link channel establishment request during the transmission timing search or a normal link channel establishment request. A configuration is adopted in which information that can be distinguished by the device is inserted into an option bit of a link channel establishment request signal.

According to this configuration, the base station apparatus can again receive a link channel establishment request from the same communication terminal apparatus immediately after assigning a link channel,
It is possible to shorten the timing search time.

According to the communication terminal apparatus of the present invention, in the above-described configuration, when the transmission window is determined by searching for the transmission timing, the window width receivable by the base station apparatus is assumed to be _tw, and _tw / 2 is defined as the step width of the transmission timing. , it transmits a signal to the base station apparatus sequentially shifting the transmission timing in this width, a configuration that determines the optimal transmit timing by subtracting the correction width ± t _w / 4 according to the response state for the transmission.

According to this configuration, the transmission timing can be adjusted within ± _tw / 4 with respect to the center value of the reception window width of the base station device by optimizing the step size of the transmission timing of the communication terminal device. it can.

The fixed subscriber terminal of the present invention employs a configuration including a communication terminal having the same configuration as any one of the above.

According to this configuration, in the fixed subscriber terminal device, the same operation and effect as any of the above can be obtained.

The automatic transmission timing setting method according to the present invention comprises:
In the communication terminal device, an initial value of the transmission timing is determined according to the received electric field strength from the base station device, and a transmission timing capable of communicating with the base station device is searched while shifting the transmission timing from the determined initial value. And set it.

According to this method, the transmission timing to the base station device can be automatically adjusted, and thereby the installation work of the communication terminal device can be easily performed.

The automatic transmission timing setting method of the present invention comprises:
In the above method, a response to the link channel assignment signal from the base station device is not returned from the communication terminal device, and the link channel establishment request is completed when the timer of the base station device expires.

According to this method, the transmission timing can be adjusted without increasing useless traffic and without affecting existing base station equipment.

The automatic transmission timing setting method according to the present invention comprises:
In the above method, an instruction to complete the link channel establishment request is issued immediately after returning the link channel assignment signal in the base station apparatus by the option bit of the link channel establishment request signal.

According to this method, the time for adjusting the transmission timing can be reduced.

[0053]

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

(Embodiment) FIG. 1 is a block diagram showing a configuration of a fixed subscriber terminal device in a WLL system according to an embodiment of the present invention.

The WLL system shown in FIG. 1 includes a base station concentrator 102 connected to a network 101 such as a public or private line, a plurality of base stations 103 connected to this apparatus 102, A plurality of fixed subscriber terminal devices 104 for communication, and a fixed subscriber terminal device 10;
Telephone 105 and maintenance jig 10 connected to 4
6 is provided.

The fixed subscriber terminal device 104 includes a radio unit 110 and a BMC (Burst Mode Controller) unit 111.
, Control unit 112, and subscriber line IF (interface)
It comprises a unit 113 and a data storage unit 114.

The radio section 110 performs radio communication with the base station 103 and has a configuration (not shown) for measuring the received electric field strength.

The BMC unit 111 performs burst mode control for controlling burst communication for the TDMA or TDD communication system, and generates or reproduces a voice codec and a baseband signal necessary for modulation and demodulation. Also,
The control unit 11 also has a function of adjusting the transmission timing.
2 is controlled.

The control unit 112 performs various controls of the communication protocol and the fixed subscriber terminal device 104, and has an external IF.
Arbitrarily, so that the data in the data storage unit 114 can be updated.

The subscriber line I / F unit 113 includes a telephone 105
And other communication devices.

The data storage unit 114 uses a non-volatile memory, and includes subscriber data for authentication required for communication and an identification code (hereinafter referred to as I) of the base station 103 capable of registering a location.
D), transmission timing information that differs for each base station 103, and the like, so that data is retained even when the power is turned off. Further, such data can be updated / changed from outside via the control unit 112.

The operation of such a configuration will be described. First, a description will be given with reference to FIG. FIG. 2 is a state transition diagram of an automatic transmission timing setting operation by the fixed subscriber terminal device in the WLL system according to the embodiment of the present invention.

The state shown in FIG. 2 is significantly different from the conventional state in that states 30 to 311 are different from state 30 in FIG.
9, 310, and 311 are added.

First, after power is turned on in state 300, in state 301, a search is made for a base station 103 that can be a candidate for a nearby location registration. The condition is that the base station 103 that can be a candidate has the base station ID of the own system and that the average value of the received electric field level is a certain value or more. In this case, the candidate base station is stored in a volatile memory as temporary data.

Here, if the location registration is completed even once, and there is no new candidate base station 103, the state immediately transits to the state 302 in order to perform the location registration with respect to the previously registered base station 103. .

The conventional state after the transition to the state 302 and before the transition to the battery saving mode in the state 307 is as described in FIG.

In the state 301, if the location registration is the first time, or if a new candidate base station 103 is found, the state transits to the state 309.

Hereinafter, the state transition which is a feature of the present invention will be described.

In state 309, the initial value of the transmission timing is determined according to the reception electric field level of candidate base station 103. That is, if the level of the received electric field from the candidate base station 103 is low, it is determined that the base station 103 is far, and the initial value at the time of determining the timing is set to a long distance, and the timing adjustment is started. If the base station 103 has both high and low transmission powers, the base station 103 is identified by the ID of the base station 103 so that the timing can be corrected.

Further, the purpose here is to shorten the search time for the optimum transmission timing only by determining the initial value of the transmission timing. Therefore, if the optimum timing of the base station 103 cannot be found with the initial value, the initial value can be changed and the search can be performed again. When the transmission timing search initial value is determined for each new candidate base station 103, the initial value is temporarily stored, and the state transits to the state 310 in which the optimum transmission timing is determined.

In state 310, the transmission timing of candidate base station 103 for performing location registration is determined. The transmission timing is slightly shifted from the initial value for each base station 103, a link channel establishment request is attempted, and this is repeated until there is a response from the base station 103.

When the optimum transmission timing is determined, it is stored in the data storage unit 114, which is a non-volatile memory, in association with the base station ID. So that there is no

FIG. 3 shows a communication flow at this time. As shown in FIG. 3, a request 301 for establishing a link channel is sent from the terminal device 104 to the base station 103 using a common control channel, and if the base station 103 can accept the request, a link channel allocation 302 Will be returned.

At this time, the link channel establishment request 30
1 is the earliest stage of communication link establishment, and it is assumed that the response process is completed only by the base station 103. Therefore,
This processing does not extend to the base station concentrator 102,
The impact on communication traffic is small.

At the time of timing adjustment, the terminal device 104 does not respond to the link channel allocation from the base station 103. Therefore, the base station 103 responds to the request from the terminal device 104 in response to the request from the terminal device 104. Only by the expiration of the timer waiting for the response, the difference between the timing adjustment link channel establishment request and the normal link channel establishment request will be distinguished.

In this case, at the time of timing search, the time for issuing a new link channel establishment request for the next timing search is restricted by the time length of this timer.
However, in order to indicate that the link channel establishment request from the terminal device 104 is a link channel establishment request signal whose timing is being adjusted, it is possible to give meaning to the option bits in this message.

In this way, immediately after allocating the link channel, base station 103 can again receive a link channel establishment request from same terminal apparatus 104,
It is possible to shorten the timing search time.

The terminal device 104 cannot transmit the next link channel establishment request until the base station 103 returns the link channel allocation request after requesting the link channel establishment. However, if the transmission timing is not appropriate and the base station 103 cannot correctly receive the link channel establishment request, the terminal device 104 transmits the next link channel establishment request until the timer for waiting for the link channel allocation expires. Shall not be issued.

FIG. 4 shows a detailed state transition diagram of the state 309 in FIG. 2, and a supplementary explanation will be given.

In the states 401 to 407 in FIG. 4, the transmission timing is sequentially shifted, and a link channel establishment request is made within a range not exceeding the limit value of the transmission timing.
03 describes a method for determining whether a signal from the terminal device 104 can be normally received.

If a new base station 103 is found while waiting, if it is necessary to perform location registration as shown in a state 407, the state transits to the state 302 in FIG. Otherwise state 307 as shown
Transitions to.

This criterion is, for example, a case where the newly found base station 103 has a received electric field larger than that of the base station 103 whose location is already registered. However, this criterion is not necessarily restricted by the request of the system.

In the state 403, when the transmission timing exceeds the limit value, the base station 103 is deleted from the candidate base station 103 table in the immediate state 404. This is an example, and the state may be changed to the state 401 so as to change the initial value and retry.

The state 406 describes the process from the first link channel assignment to the determination of the optimum transmission timing. As an example, the operation in this state 406 will be supplementarily described with reference to FIG. 5, but setting the optimum timing is not necessarily based on the present method.

FIG. 5 is a supplementary state transition diagram of the state 406 in FIG.

In the states 501 to 508 in FIG. 5, after the first link channel request is made, the transmission timing is determined by at least two more link channel establishment requests until the optimum timing is determined. It shows a method of falling within (± _tw / 4) with respect to the receiving window width center value of 103. Here, _tw is the receivable window width of the base station 103.

FIG. 6 shows how the base station 103 can receive the window width _tw and how the terminal device 104 adjusts the transmission timing at this time.

The basic principle is that the transmission timing adjustment width of the terminal device 104 is shifted a little at a time ( _tw / 2), and the base station 103 responds to the link channel establishment request.
The optimal timing is determined by dividing the situation of the response from the four cases into four cases as shown in FIG.

In the first to third cases, the optimum transmission timing can be determined by two link channel establishment requests, but in the fourth case, n link channel establishment requests are required.

In the first and second cases, since the base station 103 allocates a link channel in the second link channel establishment request, (t)
_The timing obtained by subtracting _w / 4) is set as the optimum timing.

In the third case, since the base station 103 does not respond to the second link channel establishment request, the timing obtained by subtracting ( _tw / 4) from the first transmission timing is defined as the optimum timing. I do.

In the case of the fourth case, the base station 103 continuously responds to the (n-1) th link channel establishment request without any response, and the link channel is allocated for the first time by the nth link channel establishment request. The timing obtained by subtracting ( _tw / 4) from the n-th transmission timing is set as the optimum timing.

If such an algorithm is used, the center value of the reception window width of base station 103 is (± t
The transmission timing of the terminal device 104 can be adjusted within _w / 4).

If the base station 103 cannot receive the link channel assignment even if the base station 103 can receive the signal from the terminal device 104 for some reason, it is possible to determine the correct timing by the method shown in FIGS. Can not.

In order to prevent this, a link channel for confirmation is established in state 507 in FIG. 5. If the base station 103 does not return the link channel assignment,
Next, the timing adjustment for the base station 103 is performed once again. The state 311 in FIG. 2 will be described. This state 311 is provided for the following two purposes.

One is that, after the terminal device 104 is installed once, in order to improve communication traffic accompanying an increase in the number of subscribers,
This is because even when the base station 103 is newly installed, the optimum transmission timing to the new base station 103 is automatically searched for.

[0097] The second reason is that a call can be made or received while the peripheral base station 103 is being searched. New candidate base station 1
03 is detected, and when the state transits to the state 309 or 310 in order to adjust the optimal timing, the outgoing / incoming call processing cannot be performed. However, this can have less impact on operation. For example, the effect can be reduced if the notification signal transmission of the newly installed base station 103 is started during a time period when communication traffic is low, such as at midnight.

As described above, according to the fixed subscriber terminal device 104 in the WLL system of the embodiment, it is not necessary to change the conventional communication protocol. The terminal device with the automatic transmission timing adjustment function can be installed without changing the program of the existing system.

Further, a dummy link channel establishment request is repeated many times in order to adjust the transmission timing. If the system has no restriction on the use of the option bit in the link channel establishment request message, this is actively performed. , It is also possible to shorten the time for adjusting the timing of the existing base station equipment.

Also, when adjusting the transmission timing, only two signals, ie, a link channel establishment request from the terminal device and a link channel assignment from the base station, are used.
It can be completed with only the base station and the terminal device, and at first glance it seems that a useless protocol runs, but it does not greatly affect the traffic of the entire system.

Further, it is possible to reduce the data timing adjustment time for starting the timing adjustment by associating the reception field strength with the initial value of the transmission timing setting.

Further, when the optimum transmission timing is determined, this timing is stored in the non-volatile memory, so that there is no need to adjust the transmission timing after power-on after setting the transmission timing, and the operation after power-on can be performed quickly. .

Further, even after the installation, the search for the peripheral base station is continuously performed, so that it is not necessary to change the timing setting of the terminal device every time the base station is added.

Further, even when there is an outgoing / incoming call during the timing adjustment after the location registration, the outgoing / incoming call is given priority, so that the drop of the incoming / outgoing call can be reduced.

By optimizing the step width of the transmission timing of the terminal device, the transmission timing of the terminal device can be adjusted within (± _tw / 4) with respect to the center value of the reception window width of the base station.

[0106]

As described above, according to the present invention,
It is possible to automatically adjust the transmission timing to the base station, which makes it possible to easily perform terminal installation work, eliminates the need to review terminal settings every time a base station is added, and reduces traffic. Concentration can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a fixed subscriber terminal device in a WLL system according to an embodiment of the present invention.

FIG. 2 is a state transition diagram of an automatic transmission timing setting operation by the fixed subscriber terminal device in the WLL system according to the above embodiment.

FIG. 3 is a transmission flowchart at the time of automatic setting of transmission timing by a fixed subscriber terminal device in the WLL system according to the above embodiment.

FIG. 4 is a supplementary state transition diagram of the state transition 310 of the automatic transmission timing setting operation by the fixed subscriber terminal device in the WLL system according to the above embodiment.

FIG. 5 is a supplementary state transition diagram of the state transition 406 of the automatic transmission timing setting operation by the fixed subscriber terminal device in the WLL system according to the above embodiment.

FIG. 6 is a state diagram of a step width at the time of transmission timing adjustment by the fixed subscriber terminal device in the WLL system according to the above embodiment.

FIG. 7 is a diagram illustrating a correspondence between a base station response status and a transmission timing setting time of a fixed subscriber terminal device in the WLL system according to the above embodiment.

FIG. 8 is a conceptual diagram of a WLL system.

[Explanation of symbols]

 101 Network 102 Base Station Concentrator 103 Base Station 104 Fixed Subscriber Terminal 105 Telephone 106 Maintenance Jig 110 Radio Unit 111 BMC Unit 112 Control Unit 113 Subscriber Line I / F Unit 114 Data Storage Unit

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) DD25 EE10 GG01 HH21 HH23 JJ66 KK15

Claims (19)

[Claims] In a WLL system, means for determining an initial value of a transmission timing according to a received electric field intensity from a base station device, and communication with the base station device while shifting the transmission timing from the determined initial value. A communication terminal device comprising: means for searching for possible transmission timing; and means for setting the searched transmission timing. 2. The communication terminal device according to claim 1, wherein the transmission timing is set when a link channel establishment request is made at the time of first location registration immediately after power-on. 3. The communication terminal device according to claim 1, wherein the setting of the transmission timing is performed at the time of searching for a new candidate base station device satisfying the reception electric field strength. 4. A method for retrieving and setting a transmission timing when a base station apparatus does not respond to a link channel establishment request at the time of location registration, even though a received electric field strength is higher than a predetermined value. The communication terminal device according to any one of claims 1 to 3, characterized in that: 5. The non-volatile storage unit according to claim 1, wherein when setting the retrieved transmission timing, the transmission timing is stored in a nonvolatile storage unit in association with the unique information of the base station apparatus related to the transmission timing. The communication terminal device according to any one of claims 1 to 3. 6. After the location registration is completed, the reception electric field strength from the peripheral base station apparatus is periodically searched, and the search reception electric field strength exceeds a predetermined value, and the unique information of the base station apparatus of the search reception electric field strength is included. A request for establishing a link channel when the request is other than the unique information stored in the nonvolatile storage means, and in response to the request, the transmission timing at this time is associated with the unique information of the base station apparatus and the nonvolatile storage is performed. 6. The communication terminal device according to claim 5, wherein the information is stored in a means. 7. The communication terminal apparatus according to claim 6, wherein when a plurality of pieces of unique information are stored in the non-volatile storage means, the location of the unique information having a high received electric field strength is registered in the base station apparatus. 8. The communication terminal device according to claim 6, wherein when a plurality of pieces of unique information are stored in the nonvolatile storage means, the location of the unique information having a low received electric field strength is registered in the base station apparatus. 9. When an outgoing / incoming call is detected during a search for a received electric field strength from a peripheral base station apparatus, the search is stopped,
7. The communication terminal device according to claim 6, wherein the outgoing / incoming call processing is performed with priority. 10. A search for a received paging channel at the same time as a request for a link channel allocation request from said peripheral base station device so that an incoming call is not lost when searching for a received electric field strength from a peripheral base station device. The communication terminal device according to claim 6, wherein 11. The apparatus according to claim 1, further comprising means for storing a relation between the transmission timing and the received electric field strength in a table, and connecting an external device for changing the stored transmission timing. The communication terminal device according to any one of the above. 12. The communication terminal device according to claim 11, further comprising means for correcting a table storage value according to a unique information signal of the base station device when the received field strength stored in the table is different. . 13. The system according to claim 11, wherein when the transmission timing is changed from an external device, the transmission timing can be moved forward and backward by ± X symbols within a range of ± X symbols around the standard transmission timing. The communication terminal device according to claim 1. 14. When a link channel establishment request is made during a transmission timing search, information that allows the base station apparatus to distinguish between the link channel establishment request during the transmission timing search and a normal link channel establishment request is transmitted. 4. The communication terminal device according to claim 1, wherein the communication terminal device is inserted into an option bit of the request signal. 15. A time determination by searching transmission timing, when a receivable window width of the base station apparatus and a t _w, the t _w / 2 and step size of the transmission timing, by shifting the transmission timing in this width sequential to the base station apparatus transmits a signal, the correction width ± t _w according to the response state for the transmission
4. The communication terminal device according to claim 1, wherein an optimal transmission timing is determined by reducing / 4. 16. A fixed subscriber terminal device comprising the communication terminal device according to claim 1. Description: 17. A communication terminal device, wherein an initial value of a transmission timing is determined according to a received electric field strength from a base station device, and communication with the base station device can be performed while shifting the transmission timing from the determined initial value. A transmission timing automatic setting method characterized by searching for and setting a proper transmission timing. 18. The communication terminal apparatus according to claim 17, wherein a response to the link channel assignment signal from the base station apparatus is not returned from the communication terminal apparatus, and the link channel establishment request is completed when the timer of the base station apparatus expires. Automatic transmission timing setting method. 19. The automatic transmission timing according to claim 18, wherein an instruction bit for completing the link channel establishment request is issued immediately after returning the link channel assignment signal in the base station apparatus by an option bit of the link channel establishment request signal. Setting method.