JP3319587B2 - Wireless local loop system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless local loop system in which a radio section exists in an access network between a subscriber terminal and a local exchange.

[0002]

2. Description of the Related Art In order to construct a subscriber telephone service economically, a wireless local loop (WLL: Wireless Local Lo) is provided in which an access network between a subscriber terminal and a local exchange is provided with a wireless section.
op) systems have been proposed.

FIG. 4 is a block diagram showing a configuration example of a general WLL system. In the example shown in FIG. 4, a WLL system 900 is constructed between a subscriber terminal and a local exchange. Subscriber terminal (hereinafter referred to as terminal) 6
Is connected to the access base station 400 via the access terminal unit 500 having a wireless transmission / reception function and a wireless line.
Exchange interface unit (exchange IF unit) 200 serves as an electrical and physical interface with exchange 1 and, when detecting an incoming call from exchange 1, notifies control unit 300 of the detection of the incoming call.

[0004] As an interface with the exchange 1, a two-wire metallic wire for an analog interface,
If it is a digital concentrator interface, ITU-T recommendation G. V5.1 and V5.2 defined by G.964 and G965
Is used. In any case, the exchange 1 accommodates a subscriber terminal using an analog line. Hereinafter, description will be made on the assumption that the switching device 1 is connected to the switching device 1 by a 2W interface.

[0005] The control unit 300 includes a time-division communication path switch (TSW) 301 and sets a connection between the exchange 1 and the terminal 6. Access base section 400 establishes a wireless link with access terminal section 500 in response to an instruction from control section 300.

[0006] Incidentally, a Calling Number Deliverer for notifying a called party of a calling party's telephone number and the like.
The y service (caller ID display service) has become popular. The caller number display service is a general term for a pre-call information notification service between subscribers, although the name and specifications are different in each country, as called a number display service in Japan and a Caller ID in the United States.

The operation for realizing a pre-call information notification service in a WLL system will be described below with reference to FIGS.
This will be described with reference to the sequence diagram of FIG. Here, it is assumed that the subscriber having the terminal 6 has exchanged a contract or the like with the communication company that operates the exchange 1 to enjoy the pre-call information notification service. Here, an NTT number display service provided in Japan as a pre-call information notification service is taken as an example.

First, an incoming call activation without a number display service will be described with reference to FIG. The exchange interface unit 200 has a detection function relating to the activation of an incoming call, such as the detection of the inversion from the exchange 1 or the detection of a call signal. As shown in FIG. The control unit 300 is notified that the signal has been detected. Further, switch interface section 200 notifies ringing and silent in the call signal to sequential control section 300. Therefore, control section 300 can identify the ringing pattern of the calling signal from the detection timing of ringing and silent.

[0009] As shown in FIG. 5, the control unit 300 activates the incoming call to the access base unit 400 when the switching interface unit 200 is notified of the detection of the inversion or the detection of the calling signal. In addition, a downstream (switch → terminal) connection of the TSW 301 is set. Access base section 400 activates an incoming call to access terminal section 500 in response to an incoming call from control section 300. As described above, the access base unit 400 immediately activates the incoming call immediately after the switching interface unit 200 detects the reversal or the call signal.
This is because it is expected that it will take a long time to establish a wireless communication link with 00. That is, since the access base unit 400 immediately activates the incoming call, the processing delay of the call processing sequence can be reduced.

[0010] As shown in FIG. 5, the control unit 300, which has already activated the incoming call, notifies the access base unit 400 of the identified pattern signal when the identification of the call signal pattern is completed. Upon receiving the pattern signal, access base section 400 notifies access terminal section 500 of the pattern signal if a communication link with access terminal section 500 has been established. Upon receiving the pattern signal, access terminal section 500 acts on terminal 6 as if it were an exchange.

That is, while performing the reversal control, a calling signal is given in accordance with the pattern signal received from access base section 400. Specifically, sounding is performed while timing is controlled in accordance with the pattern signal. Normally, at the time of general incoming call in Japan, a ringing is performed with a ringing pattern of 1 second / 2 seconds called IR.

If the terminal 6 is a telephone, the subscriber
Answering the handset, the access terminal 500
Detects off-hook and stops ringing. Then, as shown in FIG. 5, the access base unit 400 is notified of the subscriber's off-hook. When notified of the subscriber's off-hook from access terminal section 500, access base section 400 notifies control section 300 of the off-hook. Then
The control unit 300 notifies the exchange interface unit 200 of the off-hook, and the exchange interface unit 200 notifies the exchange 1 of the off-hook. The control unit 300
Sets an up (terminal-to-exchange) connection of the TSW 301.

When the exchange 1 is notified of the off-hook,
It is determined that the terminal 6 has responded to the call, and the process returns. This signal is also transmitted to the exchange interface unit 200 and the control unit 30.
0, access base unit 400 and access terminal unit 500
Is transmitted to the terminal 6 via. At this time, the connection between the terminal 6 and the exchange 1 is established, and the terminal 6 shifts to a call state.

After the end of the call, when the subscriber of the terminal 6 hangs up, the access terminal unit 500 detects an on-hook as shown in FIG. The fact that the terminal 6 goes on-hook
The information is transmitted to the exchange 1 via the access base unit 400, the control unit 300, and the exchange interface unit 200. Further, the control unit 300 to which the on-hook has been notified notifies the access base unit 400 of the end of the call,
The connection of both upstream and downstream of 301 is released. The access base unit 400 that has received the end signal transitions to an idle state. At this point, all the connections between the terminal 6 and the exchange 1 are released, and the state shifts to an empty state.

The above description is of the operation in the case where the number display service is not involved. However, in the case where the number display service is accommodated, a delay from activation in a wireless section to establishment of a line in the WLL system is caused by the following. The problem is that the transmission of the terminal primary response (off-hook) to the exchange 1 is delayed. That is, the probability of the timeout of the waiting timer T0 from the incoming call activation to the terminal primary response in the exchange 1 increases, and it may not be possible to notify the terminal 6 of the caller telephone number.

Specifically, as shown in FIG. 6, when a number display service is involved, the exchange 1 outputs a call signal according to a CAR pattern which is a service start signal unique to the operator, and outputs a call signal until the terminal primary response. Wait timer T0
Start When the timer T0 times out for the above-described reason, the exchange 1 shifts to calling according to a normal pattern without outputting caller telephone number information.

In order to make effective use of channel resources in the radio section, the access terminal unit 500 sets the access base unit 400 as an upper station when the terminal 6 goes on-hook.
Has a function of autonomously opening a line when a line release signal is not transmitted from the device. This is also a problem when accommodating the number display service.

For example, as shown in FIG. 7, the terminal primary response is transmitted before the timer T0 of the exchange 1 times out, the information transmission such as the caller telephone number information is completed, and the on-hook which is the reception completion notification is transmitted. Even when the timer T1 (starting from completion of information transmission) for monitoring the reception completion notification wait in the exchange 1 is transmitted before the timeout, the access terminal unit 500 may temporarily open the line. That is, if the line release signal to be received at that time cannot be received before the timeout period of the line release signal waiting timer due to a delay in the wireless section, the access terminal unit 500 performs reverting control on the terminal 6. .

Then, the terminal 6 does not necessarily display the caller ID correctly because it is regarded as abandoned during the call. The terminal 6 responds to the incoming call based on an activation signal (IR) transmitted in response to the exchange 1 detecting the terminal primary response.

[0020]

As described above, in a WLL system in which a radio section is interposed in an access network between a subscriber terminal and a local exchange, there is a case where the pre-call information notification service does not function. There is a problem that there is.

[0021] Therefore, an object of the present invention is to provide a WLL system capable of reliably operating a pre-call information notification service.

Incidentally, an invention having a similar object is disclosed in
Although disclosed in Japanese Patent Publication No. 0-308811, the invention solves the problem by storing caller ID information from the exchange in the control unit. However, according to such a solution, although the problem due to the timeout of the timer T0 in the exchange can be avoided, it cannot cope with the problem due to the autonomous line release function of the access terminal unit.

[0023]

A WLL system according to the present invention detects a call signal pattern from an exchange and sets up a connection between the exchange and a subscriber terminal, and a call signal from the exchange. A signal analyzing unit that analyzes pre-call information from the exchange when the pattern is a call signal pattern of the pre-call information notification service, and the control unit transmits to the exchange in response to the call signal of the pre-call information notification service. On the other hand, the access terminal behaves as a subscriber terminal, and behaves as an exchange for the subscriber terminal when the access terminal receives a notification of the pre-call information notification service from the control unit.

Further, the WLL system according to the present invention detects a pattern of a call signal from the exchange and sets a connection between the exchange and the subscriber terminal. A signal analysis unit for analyzing pre-call information from the exchange when the call signal pattern of the information notification service is provided, wherein the control unit makes a primary response to the exchange in response to a call signal of the pre-call information notification service When the signal analysis of the signal analysis unit is completed, the reception completion notification is sent to the exchange, and the pre-call information notification service and the pre-call information are transmitted to the access terminal unit via the access base unit, When the access terminal receives a notification of the pre-call information notification service from the control unit, the access terminal unit calls the pre-call information notification service to the subscriber terminal. And wherein the sending the call before information.

The access terminal unit is configured not to execute autonomous line release from transmitting the pre-call information to the subscriber terminal until transmitting the call signal transmitted after the primary response of the subscriber terminal. You may. According to such a configuration, the call processing sequence can be continued without always releasing the line, and the pre-call information is prevented from being transmitted to the subscriber terminal due to the autonomous line release.

[0026] The access base unit may be configured to transmit the pre-call information notification service and the pre-call information to the access terminal unit on a channel different from the call channel. According to such a configuration, a pre-call information notification service is realized without wastefully occupying channel resources in a wireless section.

When the control unit detects that the pattern of the call signal from the exchange is a call signal pattern of the pre-call information notification service, the control unit is configured to set up a connection between the exchange and the signal analysis unit. You may. According to such a configuration, the signal analysis unit can be brought into the operating state by using the switch for setting the connection in the control unit.

When the radio link between the access base unit and the access terminal unit is established, the control unit releases the connection between the exchange and the signal analysis unit and establishes a bidirectional connection between the exchange and the subscriber terminal. It may be configured to set. According to such a configuration, even if the signal analysis unit is operated using the connection setting switch in the control unit, the connection for the call is not affected.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of a WLL system according to the present invention. In the example shown in FIG. 1, the terminal 6 is connected to the access base station 4 via an access terminal unit 5 having a wireless transmission / reception function and a wireless line. The access base station 4 includes a WLL system control unit 10
Is connected to the exchange 1.

In the WLL system control section 10, the exchange interface section (exchange IF section) 2 has an electrical and physical interface with the exchange 1 and detects an incoming call from the exchange 1. Notify. The control unit 3 includes the TSW 31 and sets a connection between the exchange 1 and the terminal 6. The signal analysis unit 8 has a built-in demodulator, analyzes information from the exchange 1, and notifies the control unit 3 of the analysis result.

The access base unit 4 is connected to the WLL system control unit 10 by a digital line, and establishes a wireless link with the access terminal unit 5 connected to the terminal 6 according to an instruction from the control unit 3. .

The maintenance terminal 7 registers the terminal 6 in the WLL system, and notifies the control unit 3 in advance that the terminal 6 is a subscriber of the pre-call information notification service via an in-system maintenance operation signal transmission route. .

The access terminal unit 5 is installed in the subscriber's house or near the subscriber's house. In addition, the WLL system control unit 10 is installed in a station where the exchange 1 is installed or in a location related to a communication carrier. And
The WLL system includes an access terminal unit 5, an access base unit 4, and a WLL system control unit 10.

The signal analyzer 8 is interfaced with the TSW 31 via a digital highway. The processing capacity is optimized at the time of system design according to the number of accommodated pre-call information notification service subscribers, the number of simultaneous incoming calls, the maximum number of simultaneously accommodated channels in a wireless section, and the like.

Next, the operation will be described. even here,
The description will proceed on the assumption that the exchange interface unit 2 and the exchange 1 are connected by a 2W interface. Also,
It is assumed that the subscriber having the terminal 6 has exchanged a contract with the communication company that operates the exchange 1 to enjoy the pre-call information notification service.

When the exchange interface unit 2 detects information on the activation of the incoming call such as the reversal of the polarity from the exchange 1 or the ringing of the calling signal, the exchange interface unit 2 notifies the control unit 3 of the detection of the activation of the incoming call. Further, the exchange interface unit 2
The ringing and the silent in the call signal are sequentially notified to the control unit 3. Therefore, the control unit 3 can identify the ringing pattern of the call signal from the detection timing of ringing and silent.

When the identification of the call signal pattern is completed, the control unit 3 determines whether or not the pattern is a pre-call signal unique to the operator in the pre-communication information notification service. It is also determined whether the called subscriber is a pre-call information notification service subscriber registered in advance. If the incoming call is a call to the pre-call information notification service subscriber and the paging signal pattern is an operator-specific pre-call signal in the pre-communication information notification service, the control unit 3 sets the corresponding subscriber channel of the exchange interface unit 2 to the corresponding one. , A downlink connection to be connected to the signal analyzer 8 via the TSW 31 is set.

Based on the pre-call information notification service specification of the exchange 1, the control unit 3
Alternatively, after acting as a pre-call information notification service terminal and instructing the exchange interface unit 2 to perform an off-hook corresponding to a primary response from the terminal 6 to make a primary response to the exchange 1, the signal analysis unit 8 Wait for an information signal sent from 1. The signal analysis unit 8 is connected to the TSW 31 in the control unit 3 by a data highway, and receives an FSK signal carrying an information signal from the exchange 1 for each subscriber. Since the corresponding subscriber channel is connected to a time slot specified in advance by the control unit 3 on the data highway, the signal analysis unit 8 outputs a valid FSK signal from the exchange 1 (an FSK signal corresponding to the corresponding subscriber). ) Can be received.

If a valid FSK signal is received,
The signal analyzer 8 outputs the data obtained by demodulation to the controller 3 as reception valid data (reception message). In addition, the signal analysis unit 8 is partly involved in the content of the received message. For example, the message length is identified from the data format based on the pre-call information notification service specification, and the number of received data is counted to identify the completion of the message reception. Then, the completion of the reception is notified to the control unit 3 together with the reception message. Since the control unit 3 can recognize the reception completion only by waiting for the notification from the signal analysis unit 8 without analyzing the message, the load required for the control unit 3 to receive the information is reduced.

The signal analyzer 8 also analyzes received data errors such as data length / parity determination, message format determination, checksum or CRC determination.
When an error is detected, the controller 3 is notified of the error. This also reduces the load required for the control unit 3 to receive information.

When receiving a notification of the completion of the message reception from the signal analysis unit 8, the control unit 3 notifies the exchange 1 of the completion of the reception by performing an on-hook notification when it is necessary to notify the reception completion. The exchange 1 thereafter shifts to a normal call signal transmission state and waits for an off-hook from the terminal 6.

The control unit 3 notifies the access base unit 4 of the incoming call start including the identified call signal pattern and the information indicating that the incoming call is a notification of the pre-call information notification service. In addition, a received message input from the signal analysis unit 8, for example, caller number display information is also notified. The access base unit 4 activates the incoming call to the access terminal unit 5, and notifies the identified call signal pattern, the fact that the incoming call is the pre-call information notification service, and the received message. Each piece of information is transmitted as out-of-band information instead of in-band information used for a call in a wireless section.

When a wireless communication link with the access terminal unit 5 is established, the access base unit 4 immediately notifies the control unit 3. Further, when the access terminal unit 5 receives the incoming call activation, the access terminal unit 5 behaves as if it were the exchange 1 to the terminal 6, performs the reversal control, and generates a call signal according to the pattern signal received from the access base unit 4. give. Specifically, sounding is performed while timing is controlled in accordance with the pattern signal.

When notified of the establishment of the communication link from the access base unit 4, the control unit 3
Release the downlink connection between the signal analyzer 8 and the
A bidirectional connection between the exchange 1 and the terminal 6 is set in the SW 31.

After notifying the caller number display information and the like, the access terminal unit 5 shifts to transmitting a normal call signal (IR) when a predetermined time elapses based on the pre-call information notification service specification. During this time, if there is a primary response (off-hook) or a reception completion notification (on-hook) from the terminal 6, the terminal 6 and the terminal 6 can communicate with each other without releasing the wireless communication link and without the notification of the access base unit 4. During this period, a series of incoming operations is continued, and a transition is made to ringing processing based on a normal ringing signal pattern.

The terminal 6 according to the normal calling signal pattern
Off-hook is detected by the access terminal unit 5. Information indicating off-hook is transmitted to the control unit 3 via the access base unit 4. When the off-hook is notified, the control unit 3 confirms that the connection has already been set, and instructs the exchange interface unit 2 to transmit information indicating the off-hook. The exchange 1 establishes a connection assuming that there is a secondary response in the pre-call information notification service by off-hook.

As described above, in this embodiment, when the signal analysis unit 8 detects a received message including caller number display information and the like, the control unit 3 sends an incoming call notification including the information to the access base unit 4. The information is transmitted to the access terminal unit 5 via the communication terminal 1 and a primary response is sent to the exchange 1. Also, the access terminal unit 5 continues a series of incoming operations with the terminal 6 until a ringing process based on a normal call signal pattern. Therefore, in the exchange 1, the timer T0 waiting for the primary response does not time out, and the timer T1 monitoring the reception completion notification waiting of the pre-call information notification service does not time out. Further, there is no possibility that the access terminal unit 5 autonomously opens the line.

Next, a more specific operation will be described with reference to the sequence diagram of FIG. 2 and the explanatory diagram of FIG. 3, taking as an example the NTT number display service provided in Japan as a pre-call information notification service. I do.

Here, description will be made on the assumption that the exchange interface unit 2 and the exchange 1 are connected by a 2W interface. In addition, the subscriber having the terminal 6 has NT
It is assumed that the company has exchanged a contract with Company T to enjoy the number display service. Therefore, the maintenance terminal 7
Registers the terminal 6 in the WLL system, and notifies the control unit 3 in advance that the terminal 6 is a subscriber of the number display service via a system operation / operation signal transmission route.

When the switching interface unit 2 detects information on the incoming call activation such as the reversal of the switching signal or the ringing of the calling signal, the switching unit interface unit 2 notifies the control unit 3 that the incoming call activation has been detected. Further, the exchange interface unit 2
The ringing and the silent in the call signal are sequentially notified to the control unit 3.

When the identification of the pattern of the call signal is completed, the control unit 3 determines that the pattern is a CA which is a service start signal unique to the carrier in the number display service.
It is determined whether the pattern is an R pattern. It is also determined whether the called subscriber is a previously registered number display service subscriber. An incoming call to the number display service subscriber and the call signal pattern is CAR
If it is a pattern, the control unit 3 sets a downlink connection for connecting the corresponding subscriber channel of the exchange interface unit 2 to the signal analysis unit 8 via the TSW 31. Note that the CAR pattern is a repetition of ringing and silent of 0.5 seconds / 0.5 seconds.

Based on the number display service specification, the control unit 3 corresponds to the primary response from the terminal 6 to the exchange interface unit 2 within T0 (6 seconds) including the time from the detection of the incoming call to the identification of the call pattern. To send off-hook. That is, the operation is performed prior to the primary response from the actual terminal. Note that, as described above, C
Since the AR pattern is a repetition of 0.5 seconds / 0.5 seconds of ringing and silent, it does not take much time to detect the pattern. Further, the control unit 3 sets a downlink connection for connecting the corresponding subscriber channel of the exchange interface unit 2 to the signal analysis unit 8 via the TSW 31, and after a fixed time (0.3 to 1 second) from the primary response, the exchange unit 1 instructs the signal analysis unit 8 to wait for the information signal transmitted from 1.

The control unit 3 in advance on the data highway
Since the corresponding subscriber channel is connected to the time slot designated by, the signal analyzer 8 can receive a valid FSK signal from the exchange 1. When a valid FSK signal is received, the signal analyzer 8 outputs the data obtained by demodulation to the controller 3 as a received message. The signal analysis unit 8 identifies the message length from the data format based on the number display service specification, counts the number of received data, and identifies the completion of message reception. Then, the control unit 3 is notified of the completion of the reception. Further, the signal analysis unit 8 also performs received data error analysis such as data length / parity determination, message format determination, and CRC determination. When an error is detected, the controller 3 is notified of the error.

FIG. 3 is an explanatory diagram showing the format of data sent from the exchange to the terminal in the NTT pre-communication information notification service. The signal analysis unit 8 that has received the data of the format shown in FIG. 3 determines the message length and the like and performs a CRC check. When normal data is successfully received, the signal analysis unit 8 notifies the control unit 3 of the completion of message reception together with the received message.

When notified of the completion of the message reception from the signal analysis unit 8, the control unit 3 starts from the primary response for T1 seconds (7 seconds).
Within this time, an on-hook notification as a reception completion notification is sent to the exchange 1, and the process proceeds to the next process. When the on-hook is notified as the message reception completion notification, the exchange 1 shifts to a calling state as shown in FIG. That is, a normal call signal (IR) is transmitted, and the terminal 6 waits for an off-hook.

The control section 3 identifies the pattern of the call signal received from the exchange 1 via the exchange interface section 2. At this point, the call signal of the normal IR pattern is identified, but the control unit 3 identifies the previously identified call signal pattern (CAR) and the information indicating that the incoming call is a notification of the number display service. The access base unit 4 is notified of the incoming call activation (CND). Further, it also notifies the received message input from the signal analyzer 8, that is, the caller number display information.

The access base unit 4 activates the incoming call to the access terminal unit 5, and notifies the identified call signal pattern, the incoming call is the number display service, and the caller ID display information. The access terminal unit 5 starts establishing a communication link with the terminal 6 in response to the incoming call notification.

When a wireless communication link with the access terminal unit 5 is established, the access base unit 4 immediately notifies the control unit 3. When notified of the establishment of the communication link from the access base unit 4, the control unit 3 releases the downlink connection between the exchange interface unit 2 and the signal analysis unit 8 and sends the TSW 31 a connection between the exchange 1 and the terminal 6. Set up a two-way connection.

Upon receiving the incoming call, the access terminal unit 5 behaves as if it were the exchange 1 to the terminal 6, and performs the reversal control as shown in FIG. A calling signal is given according to the pattern signal received from the access base unit 4. Specifically, sounding is performed while timing is controlled in accordance with the CAR pattern signal.

As shown in FIG. 2 (B), the terminal 6 which is a terminal supporting the number display service goes off-hook as a primary response upon detecting a sound by the CAR pattern. When detecting the off-hook, the access terminal unit 5 stops the ringing and sets a predetermined time (0.3 second to 1 second) based on the number display service specification.
Seconds) later, the reception message notified from the access base unit 4 is FSK-modulated and transmitted to the terminal 6.

Upon receiving an on-hook indicating completion of message reception from terminal 6, access terminal section 5 receives a normal I
A call signal based on the R pattern is sent to the terminal 6. Then, the response (off-hook) of the terminal 6 is monitored. here,
Since the access terminal unit 5 is aware that the incoming call response control of the number display service is being performed, even if the timer for waiting for the line release signal from the access base unit 4 times out, the communication link with the terminal 6 is timed out. Do not release.

As described above, after notifying the terminal 6 of the caller ID display information, the access terminal unit 5 elapses a predetermined time (0.3 to 1 second) based on the number display service specification. Then, without releasing the wireless communication link, the access base unit 4
, Without receiving the notification, a series of incoming operations with the terminal 6 are continued, and a transition is made to a ringing process based on a normal calling signal (IR) pattern.

The terminal 6 according to the normal call signal pattern
The off-hook as a secondary response is detected by the access terminal unit 5 as shown in FIG. Information indicating off-hook is transmitted to the control unit 3 via the access base unit 4. When the off-hook is notified, the control unit 3 confirms that the connection has already been set, and instructs the exchange interface unit 2 to transmit information indicating the off-hook. The exchange 1 establishes a connection assuming that there is a secondary response in the number display service due to off-hook.

As described above, in this embodiment, the pre-call information (received message) transmitted from the exchange 1 is not directly transmitted to the terminal 6 but the WLL system control unit 1
0 once received by the signal analysis unit 8, the control unit 3
Can operate prior to the actual response of the terminal 6 to the exchange 1. Therefore, it is possible to accommodate a pre-call information notification service that is not affected by a processing delay in a wireless section in the WLL system.

When the access terminal unit 5 receives the incoming call activation, the information indicating that the incoming call is the pre-call information notification service is included in the incoming call start notification information. Even if the condition for autonomously releasing the line during the incoming call operation is satisfied, the call processing sequence can be continued without releasing the line.

Further, in a call processing sequence for realizing the pre-call information notification service, the received message received from the exchange 1 is transmitted to the radio section between the access base unit 4 and the access terminal unit 5 for a call. It becomes possible to transmit as out-band information as a message instead of in-band information to be used, and a pre-call information notification service is realized without uselessly occupying channel resources in a limited wireless section.

In the above embodiment, the number display service is taken as an example, especially in the embodiment shown in the sequence of FIG. 2, but the present invention is not limited to the various pre-call services provided by the telecommunications carriers in each country. It can be applied to the information notification service. Further, in the above-described embodiment, a 2W analog interface has been described as an example of the interface of the exchange 1, but a V5.1 or V5.2 interface may be used.

The signal analysis unit 8 can be realized by digital signal processing by an embedded processor such as a DSP or RISC processor. After the conversion, it may be configured to be processed by a logic circuit.

[0069]

As described above, according to the present invention, WLL is provided.
Since the control unit is configured so that the control unit behaves as a subscriber terminal to the exchange in response to a call signal of the pre-call information notification service, the control unit performs an operation prior to the actual operation of the subscriber terminal. This prevents the pre-call information from being transmitted to the subscriber terminal due to the time-out of the exchange.

Further, the control unit makes a primary response to the exchange in response to the call signal of the pre-call information notification service, and when the signal analysis of the signal analysis unit is completed, sends a reception completion notification to the exchange and transmits the pre-call information. The notification service and the pre-call information are transmitted to the access terminal unit via the access base unit, and the access terminal unit receives the notification of the pre-call information notification service from the control unit, and the subscriber terminal In this case, the call signal and the pre-call information of the pre-call information notification service are transmitted, so that the pre-call information notification service can be reliably functioned in the WLL system.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of a WLL system according to the present invention.

FIG. 2 is a sequence diagram showing an incoming call activation process when an NTT number display service is performed.

FIG. 3 is an explanatory diagram showing a format of data transmitted from an exchange to a terminal in the NTT pre-communication information notification service.

FIG. 4 is a block diagram illustrating a configuration example of a conventional WLL system.

FIG. 5 is a sequence diagram showing a conventional incoming call activation process without a number display service.

FIG. 6 is a sequence diagram showing a conventional incoming call activation process with a number display service.

FIG. 7 is a sequence diagram showing a conventional incoming call activation process involving a number display service.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 switch 2 switch interface 3 controller 4 access base 5 access terminal 6 subscriber terminal 7 maintenance terminal 8 signal analyzer 9 WLL system 10 WLL system controller 31 time division communication path switch (TSW)

Continuation of the front page (72) Inventor Masayuki Hagiwara 5-7-1 Shiba, Minato-ku, Tokyo Within NEC Corporation (58) Field surveyed (Int.Cl. ⁷ , DB name) H04M 3/00 H04M 1 / 26-1/57 H04M 11/00-11/10

Claims (6)

(57) [Claims] 1. A wireless local loop system provided with an access terminal unit connected to a subscriber terminal and connected to an access base unit in a wireless section in an access network between the subscriber terminal and the exchange, A control unit that detects a pattern of a call signal from the exchange and sets a connection between the exchange and the subscriber terminal; and the control unit determines that a pattern of the call signal from the exchange is a call signal of a pre-call information notification service. A signal analysis unit that analyzes pre-call information from the exchange when it is detected that the pattern is a pattern, wherein the control unit subscribes to the exchange in response to a call signal of a pre-call information notification service. before you dance to shake as terminal
Call with a primary response to serial switch, the access terminal unit is notified that a call before information notification service from the control unit performs polarity reversal control I dance to shake as exchange to the subscriber terminal
Wireless local loop system characterized Rukoto give out signals. 2. A wireless local loop system in which an access terminal for connecting a subscriber terminal and connected to an access base unit in a wireless section is provided in an access network between the subscriber terminal and the exchange, A control unit that detects a pattern of a call signal from the exchange and sets a connection between the exchange and the subscriber terminal; and the control unit determines that a pattern of the call signal from the exchange is a call signal of a pre-call information notification service. A signal analysis unit that analyzes pre-call information from the exchange when it is detected that the pattern is a pattern, wherein the control unit performs a primary operation on the exchange in response to a call signal of a pre-call information notification service. In response, when the signal analysis by the signal analysis unit is completed, a reception completion notification is sent to the exchange and a pre-call information notification service is provided. Service and the pre-call information are transmitted to the access terminal unit via the access base unit, and the access terminal unit receives a pre-call information notification service notification from the control unit. A wireless local loop system for transmitting a call signal of a pre-call information notification service and pre-call information to a subscriber terminal. 3. The access terminal unit does not execute autonomous line release from transmitting pre-call information to the subscriber terminal until transmitting a call signal transmitted after the primary response of the subscriber terminal. 3. The wireless local loop system according to 2. 4. The wireless local loop system according to claim 2, wherein the access base unit transmits the pre-call information notification service and the pre-call information to the access terminal unit on a channel different from the call channel. . 5. The control unit sets a connection between the exchange and the signal analysis unit when detecting that the pattern of the call signal from the exchange is a call signal pattern of a pre-call information notification service. A wireless local loop system according to claim 4. 6. The control unit, when a wireless link between the access base unit and the access terminal unit is established, releases the connection between the exchange and the signal analysis unit and performs bidirectional communication between the exchange and the subscriber terminal. 6. The wireless local loop system according to claim 5, wherein a connection is set.