JP2001218246A - Wireless communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively use a channel in a wireless zone. SOLUTION: When a portable phone 101 makes a request of communication with a portable phone 102 belonging to the same wireless zone A as that of the portable phone 101, a wireless base station 10 searches a dead channel of a local channel and assigns the searched idle channel s of the local channel to the portable phone 101. Thus, the portable phone 101 uses the local channel s to make direct communication with the portable phone 102 and not via the wireless base station 10. When no dead channel is available, the base station assigns a conventional cellular channel. In the case that two sets of the portable phones using the local channel are placed apart in a way of giving no interference, the base station can assign the same local channel to the two sets of the mobile phones.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system in which a plurality of mobile stations communicate using a plurality of radio zones.

[0002]

2. Description of the Related Art Automobile telephone systems and PDCs (Personal Digital Cellular telecommunications) which are known as analog cellular systems and digital cellular systems.
wireless telephone system such as a personal handyphone system (PHS).
In m), a base station and a plurality of mobile terminal stations perform communication via a time-division multiplexed (TDMA) wireless line. The base station is assigned a band of a unique frequency that does not cause interference with an adjacent base station, and a line composed of this band is subjected to a plurality of time division multiplexing (TDMA).
A plurality of telephone terminal stations and a base station can communicate with each other through the established line.

In such a cellular system, a small zone system is generally adopted, and a large number of wireless zones are arranged in a service area. It is the base station that performs communication control in each wireless zone. When a mobile phone as a mobile station talks with a general telephone, the base station controls communication in the wireless zone to which the mobile phone belongs. To the exchange, and from the exchange to the general telephone network. As a result, the mobile telephone can communicate with another telephone by being connected to a base station that controls communication in each wireless zone via a wireless line. In this case, one of the uplink channels is allocated for transmission from the mobile phone and reception by the base station,
One of the downlink channels is allocated for transmission from the base station and reception by the mobile phone. in this way,
By allocating a pair of channels, an up channel and a down channel, two-way communication can be performed.

[0004]

The above-mentioned channel assignment is similarly performed when portable telephones in the same wireless zone communicate with each other. The maximum number of channels assigned to each wireless zone is determined in advance, and a mobile phone that requests a new communication when the number of used channels reaches the maximum has no assigned channel, so it can communicate. Can not. That is, there is a problem that a call loss occurs. In particular, in recent years, information distribution such as weather forecasts and news and data distribution such as music data for ringing melody have been actively performed, and the frequency of occurrence of call loss has been increasing.

Accordingly, an object of the present invention is to provide a wireless communication system capable of preventing occurrence of a call loss by effectively using channels in a wireless zone.

[0006]

In order to achieve the above object, a wireless communication system according to the present invention is a wireless communication system having a plurality of wireless zones, and a communication system provided in each wireless zone. A base station for controlling, comprising a plurality of movable mobile terminal stations accommodated in each wireless zone, when one of the mobile terminal stations requests communication to the other mobile terminal station from the base station, The partner mobile terminal station exists in its own wireless zone or an adjacent wireless zone,
When there is a vacancy in a local channel for performing direct communication between mobile terminal stations, the vacant channel information is notified to the mobile terminal station. It is designed to directly communicate with a terminal station without passing through the base station.

In the wireless communication system according to the present invention, when the mobile terminal station that has received the notification cannot communicate with the partner mobile terminal station on the notified local channel, the mobile terminal station transmits the notification. Communication may be performed with the partner mobile terminal station via a base station. Further, in the wireless communication system of the present invention,
When a new local channel is assigned to first mobile terminal stations communicating with each other using a first local channel between second mobile terminal stations located apart from each other, the second mobile terminal When the first local channels are allocated to each other and the distances between them are so large that they do not hinder communication between the first mobile terminal stations, the second mobile terminal stations are also allocated to the second mobile terminal stations. One local channel may be allocated.

Further, in the wireless communication system of the present invention, when performing communication using a local channel, the transmission power may be controlled in accordance with the distance between the mobile terminal stations with which communication is performed. . Furthermore, in the wireless communication system of the present invention, a personal computer is connected to each of the mobile terminal station and the partner mobile terminal station, and information is transmitted between the personal computers via the mobile terminal station and the partner mobile terminal station. May be transmitted and received.

According to the present invention, when a partner mobile terminal station with which communication is to be performed exists in its own wireless zone or an adjacent wireless zone, the mobile terminal stations directly communicate with each other without passing through a base station. Since communication is performed on the local channel for communication, the channel can be used effectively. In addition, when assigning a local channel to a mobile terminal station located far from a mobile terminal station communicating using a local channel,
As long as they are separated from each other by a distance that does not hinder communication, the same local channel can be assigned, so that the channel can be used more effectively. At this time, if the transmission power is controlled in accordance with the mutual distance, even if the same local channel is assigned, communication will not be hindered.

Further, a personal computer (hereinafter, referred to as a personal computer)
In order to perform communication between PCs (hereinafter referred to as "PCs"), conventionally, a LAN (Loca
(1) Area Network), data is exchanged, or a plurality of personal computers are connected via a provider to exchange data through a provider server. In such a communication system, an extension board such as a LAN board or a cable is required, or a contract with a provider is required. However, according to the present invention, by connecting a personal computer to a mobile terminal station (mobile phone), data can be exchanged with another personal computer using a local channel. Communication can be performed between personal computers without the need for such communication.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment of a Wireless Communication System of the Present Invention
1 is shown in FIG. The wireless communication system according to the present invention employs a zone system, as in a cellular system (PDC: Personal Digital Cellular), which is a mobile communication system in Japan, and has a number of wireless zones arranged in a service area. Communication control in each wireless zone is performed by a wireless base station. For example, in wireless zone A illustrated in FIG. 1, communication control is performed by a wireless base station 10. That is, when a mobile phone as a mobile station talks with another mobile phone or a general telephone, the mobile phone is connected to the exchange via a wireless base station that controls communication in a wireless zone to which the mobile phone belongs. Will be connected to the general telephone network. Thus, a mobile phone is
By connecting via a wireless line to a wireless base station that controls communication in each wireless zone, it becomes possible to make a call with another telephone.

FIG. 1 shows a partial configuration of the wireless zone A and the wireless zone B in such a wireless communication system of the present invention.
n of n units belong to the wireless zone A. However, since the mobile phones 101 to 10n are mobile stations, when they move out of the wireless zone A, they belong to the adjacent wireless zone. Mobile phone 10 belonging to wireless zone A
Communication control is performed on the mobile phones 1 to 10n by the wireless base station 10, and a description will be given below when the mobile phones 101 to 10n communicate with a mobile phone or a general phone belonging to another wireless zone.

For example, when the mobile telephone 101 communicates with a general telephone in a general telephone network, the mobile telephone 101 sends a call signal including the other party's telephone number information to the wireless base station 10 using a control channel. Upon receiving the call signal, the wireless base station 10 allocates an available channel in the wireless zone A to the mobile phone 101 and, since the other party is a general telephone, sends the call signal to the exchange 1 which also exchanges the general telephone network. . The exchange 1 sends an incoming signal to the other party's general telephone so that the line between the general telephone and the mobile telephone 101 is connected. Thereby, the mobile phone 1
01 and a general telephone can be communicated. Note that a predetermined number of wireless channels are assigned to the wireless zone A in advance as wireless channels. Hereinafter, this wireless channel is referred to as a “cellular channel”. In the example shown in FIG. 1, the mobile phone 101 and the mobile phone 10n are communicating with another phone, and the mobile phone 101 is assigned a cellular channel a.
0n is assigned a cellular channel q.

When the mobile phone 101 communicates with a mobile phone belonging to another wireless zone, the mobile phone 101
1 transmits a call signal including the other party telephone number information to the wireless base station 10 using the control channel. The radio base station 10
Upon receiving the call signal, the mobile phone 101 displays the wireless zone A
, And confirms that the other party does not belong to the wireless zone A managed by itself, and sends the call signal to the exchange 1. The exchange 1 sends an incoming call signal to the other wireless base station that manages the wireless zone to which the other mobile phone belongs, and the other wireless base station sends the incoming call signal to the other mobile phone through the control channel. When the other party's mobile phone responds, the other party's wireless base station allocates an empty channel among the cellular channels to the mobile phone, so that the line between the other party's mobile phone and the mobile phone 101 is connected. As a result, the mobile phone 101 can communicate with a partner mobile phone belonging to another wireless zone.

Further, there is a case where mobile phones belonging to the same wireless zone communicate with each other. Conventionally, even in such a case, a cellular channel is allocated to each mobile phone and communication is performed via a wireless base station. Had gone. The wireless communication system of the present invention has a feature when mobile phones belonging to the same wireless zone or adjacent wireless zones communicate with each other. Hereinafter, the description will be made. For example, when communicating with the mobile phone 102 belonging to the wireless zone A to which the mobile phone 101 belongs, the mobile phone 10
1 transmits a call signal including the telephone number information of the mobile phone 102 to the wireless base station 10 using the control channel. Upon receiving the call signal, the wireless base station 10 determines that the mobile phone 102 that is the other party belongs to the wireless zone A, and determines whether the mobile phone 102 is available in the local channel allocated to the wireless zone A separately from the cellular channel. Search for a channel. Then, the searched empty channel s is allocated.

Here, the local channel is a special radio channel used for communication between portable telephones in the same wireless zone or for direct communication with portable telephones belonging to an adjacent wireless zone. And an interleaved channel that allows The local channel is assigned a plurality of local channels different from the wireless zone adjacent to each wireless zone. When allocating the searched empty local channel s, the wireless base station 10 transmits the channel information of the allocated local channel s to the mobile phone 101.
To the control channel. Also, the mobile phone 102 is notified of the channel information of the assigned local channel s by sending the incoming call signal on the control channel. Accordingly, the mobile phone 101 can directly communicate with the mobile phone 102 belonging to the same wireless zone without using the wireless base station 10 using the local channel s.

When allocating a local channel, the same local channel may be allocated in the same wireless zone. For example, as shown in FIG. 1, at one end of the wireless zone A, when the mobile phone 101 and the mobile phone 102 are communicating via the local channel s,
0n belongs to the same wireless zone A.
It is assumed that a communication request for (n-1) has been requested. The wireless base station 10 receiving the communication request determines that the wireless base station 10 does not interfere with each other's communication because the distance is large even if the same local channel s is assigned, and the mobile phone 10n and the mobile phone 10 (n− The local channel s is assigned to the communication with 1). In this case, in order to determine whether or not to interfere with each other's communication, the radio base station 10 determines the position of the mobile phone that is communicating and the position of the mobile phone that has newly requested communication based on the arrival direction of the signal. The distance is determined using the received power level of the signal.

However, since the degree of interference cannot be known until actual communication is performed, actual communication may be performed to notify the radio base station 10 of the situation. The radio base station 10 having received the communication status notification allocates a cellular channel again if the notification indicates that communication is not possible. Alternatively, an empty local channel may be searched again and an empty local channel may be allocated. When communication is performed using the local channel, the transmission power is controlled according to the distance between each other. By this means, when the distances are short, the transmission power can be reduced, so that the probability that the same local channel can be allocated doubly can be increased.

Further, a description will be given of a case where the portable telephone 10n belonging to the wireless zone A communicates with the portable telephone 201 belonging to the adjacent wireless zone B. In this case, the mobile phone 10n sends a call signal including the telephone number information of the mobile phone 201 to the wireless base station 10 using the control channel. Upon receiving the call signal, the wireless base station 10 determines that the mobile phone 201 that is the other party belongs to the adjacent wireless zone B, and determines the local channel assigned to the wireless zone A separately from the cellular channel. Search for available channels in. Then, the searched empty channel w is allocated. Wireless base station 1
0 assigns the searched empty local channel w and notifies the mobile phone 10n of the channel information of the assigned local channel w through the control channel. Also, the mobile phone 201 is notified of channel information of the allocated local channel w by sending an incoming call signal from a wireless base station (not shown) that manages the wireless zone B through a control channel. Thereby, the mobile phone 1
0n can directly communicate with the mobile phone 201 belonging to the adjacent wireless zone B via the local channel w without passing through any wireless base station. When communicating on the local channel, the other party's mobile phone scans the local channel at predetermined time intervals, instead of being notified of the local channel for communication,
A search may be made for a local channel having incoming call information of the own device. In this case, a local channel in an adjacent wireless zone is also scanned.

Next, FIG. 2 shows a flowchart of communication processing executed between the mobile phone and the wireless base station when a call is made in the wireless communication system of the present invention. In FIG. 2, when a call is detected in step S10 of the mobile phone,
In step S11, call information is transmitted to the wireless base station. The wireless base station receives the call information (Step S20)
Then, in step S21, the call information is interpreted to determine whether the partner station belongs to the wireless zone managed by the own wireless base station or an adjacent wireless zone. Here, if it is determined that it belongs, it is searched in step S22 whether or not the local channel has a free space. In this free channel search, even if the channel is in use, it may be assigned as a free channel if it does not interfere with communication with each other. If it is determined that there is a free channel in the local channel, step S is performed so as to allocate the free local channel.
Proceeding to 23, the channel information of the local channel allocated to the called mobile phone is notified through the control channel. At the same time, by transmitting an incoming call signal to the other station through the control channel, the assigned channel information is notified.

When receiving the channel information from the radio base station (step S12), the portable telephone sets a transmitting / receiving unit for the local channel and transmits the local channel to the partner station. Here, if the partner station replies and communication can be performed without any trouble, it is determined in step S13 that local communication is possible, and the local communication is maintained and communication is continued. If it is not determined in step S13 that the local communication is possible due to a problem in the local communication, a notification of the local communication inability is transmitted to the wireless base station through the control channel in step S14. When the wireless base station receives this local communication disable notification, it shifts to normal communication to allocate a cellular channel (step S26). At the same time, the mobile phone shifts to normal communication in step S15. Communication is thus established, and communication is continued.

Here, when the portable telephone operates the end button to end the communication, it is determined in step S16 that the communication has been ended, and the communication processing ends. Further, in the radio base station, when it is determined in step S21 that the partner station does not belong to the radio zone managed by the radio base station or an adjacent radio zone, and in step S22, an empty channel is If it is determined that there is no such communication, the process proceeds to step S26 to shift to normal communication for allocating a cellular channel. in this way,
When mobile phones belonging to the same wireless zone communicate with each other or communicate with mobile phones belonging to the adjacent wireless zone, the local channel is given priority and the traffic on the cellular channel must be reduced. And the occurrence of a call loss can be prevented as much as possible.

Next, a second embodiment of the wireless communication system of the present invention is shown in FIG. 3. In the second embodiment, communication between personal computers can be performed. As shown in FIG. 3, in the second wireless communication system of the present invention, personal computers 111 to 11n are connected to mobile phones 101 to 10n belonging to wireless zone A, respectively.
11n can transmit and receive data via the mobile phones 101 to 10n. 2. Description of the Related Art Conventionally, when data is exchanged between personal computers, a LAN (Local Area Network) that performs communication by connecting the personal computers with a cable.
rk), data is transmitted and received, and a plurality of personal computers are connected via a provider to exchange data via a provider server. However, in such a communication system, an extension board such as a LAN board or a cable is required to configure a LAN, and a contract with the provider is required to exchange data via the server of the provider.

In the second wireless communication system of the present invention, when exchanging data between personal computers, no special expansion board is required and no contract with a provider is required. Hereinafter, the second wireless communication system of the present invention will be described. For example, when the personal computer 111 communicates with the personal computer 112 connected to the mobile phone 102 belonging to the same wireless zone, the mobile phone 101 uses the control channel to transmit a call signal including the telephone number information of the mobile phone 102. And sends it to the wireless base station 10. The radio base station 10
Upon receiving the calling signal, it is determined that the mobile phone 102, which is the other party, belongs to the wireless zone A, and a search is made for a free channel in the local channel allocated to the wireless zone A separately from the cellular channel. Then, the searched empty channel s is allocated.

When allocating the searched free local channel s, the radio base station 10 notifies the mobile phone 101 of the channel information of the allocated local channel s through the control channel. Also, the mobile phone 102
Is notified of channel information of the assigned local channel s by sending an incoming call signal on the control channel. As a result, the personal computer 111 communicates with the wireless base station 1 via the mobile phone 101 using the local channel s.
It is possible to directly communicate with the personal computer 112 connected to the mobile phone 102 belonging to the same wireless zone without passing through the “0”.

As shown in FIG. 3, at one end of the wireless zone A, when the personal computer 111 and the personal computer 112 communicate with each other via the portable telephone 101 and the portable telephone 102 using the local channel s, Personal computer 1 connected to mobile phone 10n at the other end of the distance
Mobile phone 10 in which 1n belongs to the same wireless zone A
It is assumed that a request for communication with the personal computer 11 (1-n) connected to (n-1) is made. The wireless base station 10 receiving the communication request determines that the wireless base station 10 does not interfere with each other's communication because the distance is large even if the same local channel s is assigned, and the mobile phone 10n and the mobile phone 10 (n−
The local channel s is assigned to the communication with 1). In this case, the personal computer 11 (n-1) and the personal computer 1 are used even if the local channel s assigned twice is used.
In order to determine whether or not data can be transmitted and received satisfactorily to and from the mobile phone 1n, the radio base station 10 determines the position of the mobile phone that is currently communicating or the location of the mobile phone that has newly requested communication based on the arrival direction of the signal. In addition to the determination, the distance is determined using the received power level of the signal.

However, since the degree of interference cannot be known until actual communication is performed, actual communication may be performed to notify the radio base station 10 of the situation. The radio base station 10 having received the communication status notification allocates a cellular channel again if the notification indicates that communication is not possible. Alternatively, an empty local channel may be searched again and an empty local channel may be allocated. When communication is performed using the local channel, the transmission power is controlled according to the distance between each other. By this means, when the distances are short, the transmission power can be reduced, so that the probability that the same local channel can be allocated doubly can be increased.

Further, a description will be given of a case where the personal computer 11n connected to the mobile phone 10n belonging to the wireless zone A communicates with the personal computer 211 connected to the mobile phone 201 belonging to the adjacent wireless zone B. In this case, the mobile phone 10n transmits a call signal including the telephone number information of the mobile phone 201 using the control channel to the radio base station 10n.
Send to Upon receiving the call signal, the wireless base station 10 determines that the mobile phone 201 that is the other party belongs to the adjacent wireless zone B, and determines the local channel assigned to the wireless zone A separately from the cellular channel. Search for available channels in.

Then, the searched empty channel w is allocated. When allocating the searched empty local channel w, the wireless base station 10 notifies the mobile phone 10n of the channel information of the allocated local channel w via the control channel. In addition, mobile phone 2
01 is notified of channel information of the assigned local channel w by sending an incoming call signal from a wireless base station (not shown) managing the wireless zone B through a control channel. Thereby, the personal computer 11n can directly communicate with the personal computer 211 connected to the mobile phone 201 belonging to the adjacent wireless zone B via the mobile phone 10n using the local channel w without any wireless base station. become able to.

In the above description, when communication is performed between personal computers connected to mobile phones belonging to the same wireless zone,
Although the description has been given of the case where communication is performed with a personal computer connected to a mobile phone belonging to an adjacent wireless zone, the second wireless communication system of the present invention is not limited to this, and belongs to a non-adjacent wireless zone. It is possible to communicate using a cellular channel with a personal computer connected to a mobile phone, and to communicate using a cellular channel with a personal computer connected to a general telephone belonging to a general telephone network.

[0031]

As described above, according to the present invention, when a partner mobile terminal station with which communication is to be performed is present in its own wireless zone or an adjacent wireless zone, the mobile terminal stations can communicate with each other without passing through a base station. Since the communication is performed on the local channel for performing the direct communication, the channel can be used effectively. Also, when allocating a local channel to a mobile terminal station that is communicating with a mobile terminal station using a local channel, if the mobile terminal station is separated from each other by a distance that does not hinder communication with each other, the same Since the local channels are assigned, the channels can be used more effectively. At this time, if the transmission power is controlled in accordance with the mutual distance, even if the same local channel is assigned, communication will not be hindered.

Further, according to the present invention, by connecting a personal computer to a mobile terminal station (mobile phone), data can be exchanged with another personal computer using a local channel. Communication can be performed between personal computers without making a contract. Also in this case, since the local channel is assigned as the communication channel, the channel can be used effectively.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a wireless communication system according to the present invention.

FIG. 2 is a flowchart of communication processing executed between a mobile phone and a wireless base station when a call is made in the wireless communication system of the present invention.

FIG. 3 is a diagram showing a second embodiment of the wireless communication system of the present invention.

[Description of Signs] 1 switchboard, 10 wireless base stations, 101 to 10n mobile phones, 111 to 111n personal computers, 201 mobile telephones, 211 personal computers, a, q cellular channels, A, B wireless zones, s, w local channels

Claims (5)

[Claims] 1. A wireless communication system having a plurality of wireless zones, comprising: a base station provided in each wireless zone for controlling communication in the wireless zone; and a plurality of movable vehicles accommodated in each wireless zone. A terminal station, wherein when one of the mobile terminal stations requests the base station to communicate with the partner mobile terminal station, the partner mobile terminal station exists in its own wireless zone or an adjacent wireless zone, and the mobile terminal station When there is a vacancy in the local channel that directly communicates with each other, the vacant channel information is notified to the mobile terminal station, and the mobile terminal station that has received the notification communicates with the partner mobile terminal station on the notified local channel. A wireless communication system wherein direct communication is performed without passing through the base station. 2. When the mobile terminal station that has received the notification cannot communicate with the partner mobile terminal station on the notified local channel, the mobile terminal station transmits the partner mobile station via the base station. 2. The wireless communication system according to claim 1, wherein communication is performed with a terminal station. 3. A method according to claim 1, further comprising: allocating a new local channel to second mobile terminal stations located apart from each other with respect to the first mobile terminal stations communicating using the first local channel. If the distances are large enough to prevent communication between the first mobile terminal stations even if the first local channel is allocated to the second mobile terminal stations, the second mobile terminal station The wireless communication system according to claim 1, wherein the first local channel is allocated to each other. 4. The communication system according to claim 1, wherein when performing communication using a local channel, transmission power is controlled in accordance with a distance between mobile terminal stations performing communication.
A wireless communication system as described. 5. A personal computer is connected to each of the mobile terminal station and the partner mobile terminal station, and information is exchanged between the personal computers via the mobile terminal station and the partner mobile terminal station. The wireless communication system according to any one of claims 1 to 4, wherein: