JP2001333223A - Telephone communication system for discounting call tariff when making telephone call from fixed telephone set to portable telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discount a call tariff when a telephone call is made from a fixed telephone set to a portable telephone set of a calling party even without preparing a call originating side portable telephone set on the post-stage of the fixed telephone set on the user side (in the house or office of the user). SOLUTION: An interface device 3 for detecting calling from fixed telephone sets (1a-1m) to a portable telephone set 9 of the calling party and enabling communication between a radio base station 6 provided inside a prescribed area, where the fixed telephone sets (1a-1m) exist, and the fixed telephone sets (1a-1m) while utilizing an existent cable telephone line network 5 is provided between the fixed telephone sets (1a-1m) and the cable telephone line network 5 and by providing the radio base station 6 with devices (7 and 8a-8n) for enabling communication between the fixed telephone sets (1a-1m) and the portable telephone set 9 of the calling party) by calling the portable telephone set 9 of the calling party, calling from the fixed telephone set to the portable telephone set is converted into calling from the portable telephone set to the portable telephone set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone communication system for reducing a call charge when making a call from a fixed telephone to a portable telephone.

[0002]

2. Description of the Related Art Conventionally, as a means for realizing telephone communication for reducing a call charge when a call is made from a fixed telephone (general subscriber telephone; referred to as a fixed telephone in this specification) to a portable telephone, a caller has A calling mobile phone is prepared on the side of the fixed telephone, and a call (dial signal) from the calling fixed telephone to the called mobile phone is detected, and a signal related to the call is transmitted to the calling mobile phone. There has been known a communication device that transfers a call and forms a communication path between a fixed telephone and a mobile phone. Hereinafter, the communication device is referred to as a wireless transmission adapter. That is, in the conventional method of reducing the call charge when making a call from a fixed telephone to a mobile phone (hereinafter also referred to as a wireless transmission adapter method), a wireless transmission adapter is provided at the subsequent stage of the fixed telephone,
A transmitting side mobile phone is provided at a subsequent stage of the wireless transmitting adapter. In such a system, if the user also desires to perform telephone communication using a wired telephone network with the fixed telephone, the user can connect the wired telephone network to a stage subsequent to the wireless transmission adapter. What is necessary is just to comprise a wireless transmission adapter. The wireless transmission adapter is located between the fixed telephone and the wired telephone network, and is configured to control the connection between the fixed telephone and the wired telephone network.

[0003] The operation of a conventional wireless transmission adapter is as follows.
The outline is as follows. When the user calls the mobile phone of the called party from the fixed telephone of the calling party, that is, dials the telephone number of the mobile phone of the called party, the wireless calling adapter detects that, and the mobile phone sets the calling side. A call path is formed between the telephone and the fixed telephone, and the calling mobile telephone is called by the called mobile telephone. If the mobile phone of the other party answers the telephone (goes off-hook), a call path is formed between the fixed telephone and the mobile phone of the other party. You can talk to the other mobile phone. Since the call charge for making a call from a mobile phone to a mobile phone is lower than the call charge for making a call from a fixed telephone to a mobile phone, the user pays for this call. Is a call charge when a call is made from a mobile phone to a mobile phone, and the user obtains a call charge. The user pays a telephone charge for this call to a telecommunications carrier who pays a basic charge for the mobile phone of the caller (herein, the telecommunications carrier is referred to as a telecommunications carrier). By purchasing (or renting) a wireless transmission adapter manufactured by a communication device maker, a user can reduce a call charge when making a call from a fixed telephone to a mobile telephone.

[0004] However, the method of using a wireless transmission adapter to reduce the telephone charge from a fixed telephone to a mobile telephone has the following problems. First, there is a problem in that the originating mobile phone must always be provided after the wireless transmission adapter, or must be set each time a call is made to the mobile phone. Unless an existing mobile phone is used, the cost of purchasing and operating the mobile phone (the basic charge of the mobile phone) is added to the user. Assuming that a mobile phone to be set after the wireless transmission adapter uses an existing mobile phone that a user usually carries, every time a user tries to make a call from a fixed phone to a mobile phone of a called party, The user must set the calling mobile phone on the wireless calling adapter. Therefore, the conventional method is
In reality, the introduction of a system that requires the purchase of a mobile phone dedicated to a wireless calling adapter for the number of lines from which a call from a fixed phone to a mobile phone is to be discounted and paying the basic fee every month. There was a problem that operation cost was high. A product called a mobile phone has a short life cycle and new products frequently appear. When changing the mobile phone dedicated to the wireless transmission adapter, the user naturally bears the cost.

[0005] Second, there is a problem that a large cost is required every time an attempt is made to increase the number of lines for reducing the call charge from the fixed telephone to the mobile telephone. Like a user at a private home, the number of lines from a fixed phone to a mobile phone is one or two, which is cheaper.
If the book is sufficient for the user, even if the system uses a wireless calling adapter to reduce the call charge from the fixed telephone to the mobile phone, the initial one-time installation cost and the subsequent operation of the mobile phone Only cost. However, in the case of large corporate users, many caller mobile phones must be purchased at the beginning of the introduction of a call charge discount system (to mobile phones) using a wireless call adapter, A basic fee is required for the number of mobile phones. In addition, the required number of wireless outgoing adapters must be purchased. How many wireless transmission adapters must be purchased depends on the number of extensions that can be connected to the wireless transmission adapter or the number of mobile phones dedicated to the wireless transmission adapter that can be connected to the wireless transmission adapter. It is assumed that there is an establishment (user) who has drawn in 20 subscriber lines and has subscribed to a wired telephone network. It is assumed that the number of extension fixed telephones at this office is 400, for example. A private branch exchange is usually placed after the 400 fixed telephones, and if a wireless transmission adapter (single or plural) is provided, it is the latter stage of the private branch exchange. In addition, the 20 subscriber lines are drawn into the wireless transmission adapter (single or plural). If one transmitting side mobile phone is provided after the wireless transmission adapter,
One fixed telephone at a time via the calling mobile phone,
You can talk to the other party's mobile phone. However, a call cannot be made from two fixed telephones using the calling wireless telephone at the same time. Therefore, if it is desired to make a call at a reduced price when a call is made from five fixed telephones to the other party's mobile phone at a time, five outgoing mobile phones are prepared. Must be provided after the outgoing adapter. In other words, it is necessary to purchase five mobile phones and pay the basic usage fee of five mobile phones every month. In addition, for this user,
If you want to increase the number of lines to reduce the cost of calling when you make a call from your landline phone to the other party's mobile phone, you need to add six lines,
The six extensions (communication lines from the fixed telephone to the wireless transmission adapter) must be connected to the wireless transmission adapter, and an additional set of six transmitting mobile phones must be set to the wireless transmission adapter. As described above, the conventional telephone communication system for reducing the call charge when making a call from a fixed telephone to a mobile phone is desired by a large corporate user who uses a large number of extension fixed telephones. As the number of lines from a fixed telephone to a called mobile phone (the number of fixed phones that can talk to the called mobile phone at one time) increases, the cost of introducing a calling mobile phone and the cost of installing a wireless calling adapter increase. In addition, there is a disadvantage that the cost required for operating the transmitting-side mobile phone increases. This problem is caused by the fact that, in the case of a wireless transmission adapter system, in order to reduce the cost of introducing and operating the system, if the number of lines that can make a call from the fixed telephone to the other party's mobile phone at a time is small, the fixed telephone This also means that the probability of being busy when dialing into the other party's mobile phone from is increased. Therefore, in other words, it is difficult for the user to set an appropriate number of lines at which the call charge to the call destination mobile phone is discounted. If you increase the number of lines where call charges are discounted,
The cost of introducing and operating the system is high, and the use efficiency of the line for which the call charge is discounted becomes poor. Reducing the number of lines for which call rates are discounted lowers the cost of installing and operating the system, but has the annoying problem of increased busyness.

Thirdly, the conventional telephone communication system that uses a wireless transmission adapter to reduce the telephone charge when making a call from a fixed telephone to a mobile telephone has a problem of call quality. In the conventional method, that is, the wireless transmission adapter method, when a communication path is formed by a call from a mobile phone dedicated to the wireless transmission adapter, it is apparent that the communication quality becomes the communication quality of the user as it is. .
As is well known, a mobile phone does not always connect to the other party's phone no matter where it is dialed, nor does it ensure a constant call quality no matter where it is dialed. In places where radio is difficult to reach, such as in the valleys of buildings or underground, call quality is poor, sometimes it is not possible to call the other party, and sometimes the line once connected is disconnected. In the wireless calling adapter method, a calling mobile phone is installed in a place where the user is located for each user. Therefore, a call through the calling mobile phone is performed in a wireless environment where the calling mobile phone is located. And the performance of the calling mobile phone. That is, the call quality is not always guaranteed.

[0007]

SUMMARY OF THE INVENTION A telephone communication system according to the present invention for reducing a call charge when a call is made from a fixed telephone to a portable telephone in view of the above-mentioned problems of the prior art. It is an object of the present invention to solve the following problem in realizing a telephone communication system for reducing a call charge when making a call from a fixed telephone to a mobile telephone. First, at the user side (user's home or user's office), it is possible to reduce the call charge when making a call from a fixed telephone to a mobile telephone without preparing a mobile telephone after the fixed telephone. Enable. That is, the introduction cost and the operation cost of the transmitting side mobile phone are not required. Second, there is a large number of lines for which the call charge is low when a call is made from a fixed telephone to a mobile telephone, and there is no difference in user's cost burden due to the small number of lines. Users can convert up to a predetermined number of lines to lines that reduce the call charge when making a call from a fixed telephone to a mobile telephone without incurring new costs. . Unless all of the predetermined number of lines are used, it is also possible to prevent a line that reduces a call charge when a call is made from a fixed telephone to a mobile telephone from being busy. Third, it is an object of the present invention to provide a telephone communication system which can secure the quality of a call and which reduces a call charge when making a call from a fixed telephone to a mobile telephone.

[0008]

SUMMARY OF THE INVENTION A telephone communication system according to the present invention for reducing a call charge when a call is made from a fixed telephone to a mobile telephone solves the above-mentioned problems. Things.

The invention according to claim 1 has the following configuration. Paying attention to the fact that the call charge for making a call from a mobile phone to a mobile phone is lower than the call charge for making a call from a fixed phone to a mobile phone, and constructing the following communication system I do. An interface device that detects a call from a fixed telephone to a mobile phone and enables communication between the fixed telephone and a wireless base station provided in a predetermined area where the fixed telephone is located, using an existing wired telephone network. Is provided between the fixed telephone and the wired telephone network. Further, the wireless base station is provided with a device that calls the mobile phone and enables communication between the fixed telephone and the mobile phone, thereby enabling a call from the fixed telephone to the mobile phone to be transmitted from the mobile phone to the mobile phone. It is configured to be able to convert to a call.

[0010] The invention of claim 2 has the following configuration. 3. A telephone communication system according to claim 1 or 2, wherein the call charge is reduced when a call is made from the fixed telephone to the mobile telephone, wherein the predetermined area is the same as the local area code assigned to the fixed telephone. It is a local area code area.

The invention according to claim 3 is as follows. 3. A telephone communication method according to claim 1 or 2, wherein the telephone device calls the fixed telephone at a low cost when making a call from the fixed telephone to the mobile telephone. And transmits it to the radio base station. It should be noted that I in this specification
D is a number or code for specifying the subscriber line to be drawn into the user's home or the user's side of the fixed telephone as a whole or individually. Alternatively, it is a number or code for specifying the interface device.

The invention of claim 4 is as follows. 4. A telephone communication system according to claim 3, wherein a call charge is reduced when a call is made from a fixed telephone to a mobile phone. And a device for calculating a call charge between the fixed telephone and the mobile telephone based on the time of the call.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of the invention of a telephone communication system according to the present invention for reducing a call charge when making a call from a fixed telephone to a portable telephone. The communication carrier who intends to implement the present invention has a lower call charge when making a call from a mobile phone to a mobile phone than when making a call from a fixed telephone to a mobile phone. And a wireless base station 6 is provided in an area where a user who intends to obtain a communication service contract using the present invention exists. At least one fixed telephone is required on the calling side or on the side of the user's office. The fixed telephone is a wired telephone such as a key telephone, and a so-called cordless telephone is also included in the fixed telephone. On the user's side, a desired number of fixed telephones (1a, 1b
１1 m) can also be provided. Fixed telephones (1a, 1
The private branch exchange 2 is usually provided at the subsequent stage of b-1m). However, the private branch exchange 2 is not an essential component for the present invention. When there is only one or two fixed telephones at the user's home (user side), it is usual that no private branch exchange is provided. Fixed telephones (1a, 1b
１1 m) or an interface device 3 is always provided at the subsequent stage of the private branch exchange 2. The interface device 3 performs an interface between the fixed telephone and the radio base station 6 (or the subscriber line 4 or the wired telephone network 5). , Ie, the fixed telephones (1a, 1b-
1m), it is detected that the telephone number of the mobile telephone has been dialed, and the fixed telephones (1a, 1b-
1m) is a communication device that enables communication between a wireless base station 6 and a fixed telephone (1a, 1b to 1m) provided in a predetermined area where an existing wired telephone network 5 is provided. Here, the description will be continued on the assumption that a call is made from the fixed telephone 1a to the called mobile phone 9. The following description similarly applies when a call is made from another fixed telephone (1b to 1m) to the other party's mobile phone 9.

The method of detecting that the fixed telephone 1a dials the mobile telephone is a matter of design choice by those skilled in the art. For example, it is detected that the beginning of the telephone number is 090 indicating the call of the mobile telephone. You can do this by doing Alternatively, a method may be used in which a predetermined code is determined, and when a predetermined code is first sent from the fixed telephone 1a, it is detected that the call is a call to a mobile phone. The fact that the fixed telephone 1a has dialed the telephone number of the mobile phone 9 of the other party
Is detected, the interface device 3
When the wireless base station 6 answers, that is, answers the telephone, the telephone number of the destination mobile phone 9 is transmitted 4 to the subscriber line (after sending predetermined data if necessary). The telephone number transmitted to the subscriber line 4 is transmitted to the wireless base station 6 via the wired telephone network 5.

The radio base station 6 is provided with a device for calling the other party's mobile phone 9 and enabling communication between the fixed telephone 1a and the other party's mobile phone 9. The fact that the wireless base station 6 can call the called party mobile phone 9 means that the telephone number of the called party mobile phone 9 output from the interface device 3 is received and the phone number, That is, a device capable of making a call to the destination telephone 9 is provided. Specifically, the subscriber line-mobile phone interface device 7 and the mobile phone (8
a, 8b to 8n). At least one mobile phone installed in the wireless base station 6 is required. The number of the subscriber lines 4k to be drawn into the radio base station 6 and the number of the mobile phones (8a to 8n) can be determined from the fixed telephone provided by the communication carrier according to the present invention. This is a matter to be determined by taking into account how many subscribers (users) have been obtained for a service as a business for reducing the call charge when making a call to a telephone.

As shown in this embodiment, in the present invention, the fixed telephone 1a and the wired telephone network 5
(Or the subscriber line) 4 with the interface device 3
The wireless base station 6 is provided with, for example, a subscriber line-mobile phone interface device 7 and mobile phones (8a, 8b to 8n). The call from the fixed telephone 1a to the destination mobile phone 9 is made by the interface device 3 placed on the user side and the wireless base station 6 operated by the communication carrier, and the destination is called from the mobile phones (8a, 8b to 8n). Conversion into a call to the mobile phone 9 is a feature of the present invention. Here, when the telephone number of the destination telephone 9 is dialed by the fixed telephone 1a and a communication path is formed between the interface device 3 and the wireless base station 6, the wireless base station 6 switches the mobile telephone 8b. Use the other party's mobile phone 9
, The call charge when making a call from the fixed telephone 1a to the other party's mobile phone 9 is the same as the call charge when making a call from the mobile phone 8b to the other party's telephone 9 and the fixed telephone 1a. -The sum of the call charges between the wireless base stations 6.

Since the radio base station 6 is located within a predetermined area where the fixed telephone 1a is located, the call charge is small. In particular,
As described in claim 2, if the wireless base station 6 is provided in the same local station number area as the local station number assigned to the fixed telephone 1a, the distance between the fixed telephone 1a and the wireless base station 6 is limited to the local area. Since the call charge is sufficient, the call charge when making a call from the fixed telephone 1a to the other party's portable telephone 9 can be reliably reduced. At present, when making a call from a fixed telephone to a mobile phone through a normal call route, the standard call charge is 110 yen / 3 minutes, and the standard call charge for a local wired telephone line is 10 yen / 3. This is because the standard call charge when calling from a mobile phone to a mobile phone is 60 yen / 3 minutes. Therefore, according to the present invention, a call charge from a fixed telephone to a mobile phone, which costs 110 yen / 3 minutes on a normal call route, is 70 yen when a call is made from the fixed telephone 1a and a call is made to the other party's mobile phone 9. / 3 minutes. The difference between a call charge of 110 yen / 3 minutes on a normal call route and a call charge of 70 yen / 3 minutes on a call route realized by implementing the present invention, 40 yen / 3
The share is the share between the user and the carrier that implements the present invention. If the telecommunications carrier provides this to the contractor (user) for 90 yen / 3 minutes, the contractor will be 20
Yen and call charges are cheaper, and the carrier can get a gross profit of 20 yen.

If the wireless base station 6 is located at a location corresponding to the area code of the fixed telephone 1a, the call charge between the fixed telephone 1a and the wireless base station 6 and the mobile telephone 8b-the call destination mobile telephone 9 The sum of the call charges and the fixed telephone 1
The difference between the call charge and the call charge when a call is made from a to the other party's mobile phone 9 through a normal call route is a problem. If the former fee is lower than the latter fee, it is worth implementing the present invention even if the wireless base station 6 is located in an area corresponding to the area code of the fixed telephone 1a.

FIG. 2 is a block diagram showing an outline of the interface device 3. The main component is a communication path control unit 11 that controls connection and disconnection of some subscriber lines 4 drawn from the wired telephone network and the same number of local subscriber lines 4a. The interface device 3 has an ID, and stores the ID in a recording medium such as the ID recording unit 12, for example. The ID recording unit 12 is usually a ROM. As the ID, different IDs may be recorded for the number of the subscriber lines 4, or one ID may be recorded regardless of the number of the subscriber lines 4. The communication path control unit 12 is configured to read an ID from the ID recording unit 12 and transmit the ID to the subscriber line 4. Note that the ID of the subscriber line 4 may be used as the ID. In this case, the ID recording unit 12 is not always necessary. Based on an instruction from a private branch exchange (not shown) preceding the interface 3 device, the number of the subscriber line 4 selected by the interface device 3 to carry out the present invention, that is, the telephone number is I
D. The interface device 3 may or may not transmit a telephone number as an ID. In particular, the reason why the telephone number need not be transmitted is that the number of the subscriber line 4 selected by the interface device 3 is unique. This is because the ID signal to be specified is transmitted to the wireless base station 6 via a communication company that operates a wired telephone network. Specifically, if a service such as caller ID notification is used, the interface device 3, that is, a user can be specified in the wireless base station 6. In the present invention, when the configuration described in claim 3 is adopted, the interface device 3 can transmit an ID specifying the interface device 3 to the wireless base station 6 via the wired telephone network 5. It must be kept as a configuration. The ID may be the (telephone) number of each of the plurality of subscriber lines 4 drawn into the user's house, or a single number assigned to the entire plurality of subscriber lines 4 drawn into the user's house. A number for identifying the interface device 3 attached to the interface device 3 may be used. In any case, the ID specifies the user or user's home where the interface device 3 is located, and is output from the interface device 3 to the subscriber line 4 and received by the wireless base station 6. The fact that the interface device 3 transmits the ID to the wireless base station 6 means that the wireless base station 6 makes a call from the user (home) to the mobile phone based on the ID and makes a call via the wireless base station 6. This means that you can calculate call charges.

In the present invention, as described in claim 4,
The wireless base station 6 performs a call between the fixed telephone (1a, 1b to 1m) and the other party's mobile phone 9 based on the time of the call made between the fixed phone and the other party's mobile phone 9. A call charge calculation device 10 for calculating a charge for a call can be provided. The call charge calculation device 10 is specifically, for example, a personal computer system. If a personal computer system on which predetermined call charge calculation software is installed is connected to the subscriber line-mobile phone interface device 7 as the call charge calculation device 10, the call charge calculation device 10 can be connected to the fixed telephones (1a, 1b to 1). 1m) It is possible to calculate the call charge of the wired telephone line between the wireless base station 6 and the call charge of the wireless telephone line between the wireless base station 6 and the destination mobile phone 9. In the wireless base station 6, the interface device 3
Since the ID of the calling user has been received, the communication carrier implementing the present invention can calculate the call fee for each user at the wireless base station 6 and charge the user for a predetermined amount. .

[0021]

The present invention is configured as described above and has the following effects. First, at the user side (user's home or user's office), it is possible to reduce the call charge when making a call from a fixed telephone to a mobile telephone without preparing a mobile telephone after the fixed telephone. Enabled. That is, the introduction cost and the operation cost of the transmitting side mobile phone are not required. Only the interface device 3 is newly installed on the user side in order to carry out the present invention.
Can be purchased from a telecommunications carrier or borrowed free of charge from a telecommunications carrier. According to the present invention, the communication carrier can obtain a part of the discounted call charge as a profit as compared with the call charge of the normal route by implementing the present invention. It can be lent. In the past, those skilled in the art have benefited from selling wireless calling adapters. Therefore, the wireless transmission adapter could not be made free of charge. Secondly, in the present invention, the cost and operating cost for introducing a low-cost telephone call from a fixed telephone to a mobile phone are reduced when the call from the fixed telephone to the mobile phone is made. The price is constant regardless of the number of lines used to make the price lower. The user simply borrows the interface device 3 from the telecommunications carrier free of charge and has it provided between the fixed telephones (1a, 1b-1m) and the subscriber line 4. In other words, the user uses a telephone line that reduces the telephone charge when making a call from a fixed telephone to a mobile telephone at a time, up to the number of existing subscriber lines 4 that are being pulled in. can do.
The fee for the subscriber line 4 must be originally borne by the user, whether or not the present invention is implemented. According to the implementation of the present invention, the amount newly paid by the user is zero. There is no relation between the number of lines that can reduce the call charge when making a call from a fixed telephone to a mobile telephone and the amount paid by the user. Therefore, up to the maximum number of existing subscriber lines 4, the number of lines that can reduce the call charge when making a call from the fixed telephone (1a, 1b to 1m) to the destination mobile phone 9 is secured. Therefore, when dialing the telephone number of the other party's mobile phone 9 from the fixed telephone (1a, 1b to 1m), the probability that the user is busy is extremely low. Third, the call quality can be ensured.
It is possible to provide a telephone communication system for reducing a call charge when making a call from a fixed telephone to a mobile telephone. A person skilled in the art can freely select a place where the wireless base station 6 is operated in a place excellent in communication circumstances or a communication environment. In addition, the mobile phones (8a, 8b to
This is because it is possible to enhance the transmission radio wave of 8n). In other words, in the present invention, the communication quality is determined by the radio base station 6, and the radio base station 6 can be designed and operated at the discretion of the communication carrier implementing the present invention.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a telephone communication system according to the present invention for reducing a call charge when making a call from a fixed telephone to a mobile telephone.

FIG. 2 is a block diagram showing an outline of an interface device 3;

[Explanation of symbols]

 1a, 1b, 1m Fixed telephone 2 Private branch exchange 3 Interface device 4 Subscriber line 4a Private subscriber line 5 Wired telephone line network 6 Wireless base station 7 Subscriber line-mobile telephone interface device 8a, 8b, 8n Mobile telephone 9 Call partner Destination mobile phone 10 Call charge calculation device 11 Call path control unit 12 ID storage unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K025 AA08 DD06 5K067 AA21 BB04 DD17 EE02 EE10 EE16 HH24 5K101 LL01 LL12 MM06 NN48 QQ07 QQ11

Claims (4)

[Claims] Focusing on the fact that the call charge for making a call from a mobile phone to a mobile phone is lower than the call charge for making a call from a fixed telephone to a mobile phone, An interface device that detects a call to a mobile phone and enables communication between a wireless base station provided in a predetermined area where the fixed telephone is located and the fixed telephone using an existing wired telephone network, In addition to providing between the fixed telephone and the wired telephone network, the wireless base station is provided with a device for calling the mobile telephone and enabling communication between the fixed telephone and the mobile telephone. When a call is made from a fixed telephone to a mobile phone, the call to the telephone is converted into a call from the mobile phone to the mobile phone. A telephone communication system that reduces the cost of telephone calls. 2. The call charge for making a call from a fixed telephone to a mobile phone according to claim 1, wherein said predetermined area is the same local office number area as a local office number assigned to said fixed telephone. Telephone communication system to be cheaper. 3. The fixed telephone to the mobile telephone according to claim 1, wherein said interface device transmits an ID specifying itself to said wireless base station via said wired telephone network. A telephone communication system that reduces the cost of calling when making a call to. 4. An apparatus for calculating, by the radio base station, a call charge between the fixed telephone and the mobile phone based on a time of a call made between the fixed telephone and the mobile phone as a communication partner. 4. A telephone communication system according to claim 3, wherein a call charge is reduced when a call is made from a fixed telephone to a mobile telephone.