Mobile communication system and method for performing communication control within a base station and a mobile station

A mobile communication system includes a base station and a mobile station, the base station including reporting unit that reports information to the mobile station, considering the transmission output difference to the mobile station; the mobile station including receiving unit that receives the broadcast information reported from the reporting unit of the base station and control unit that controls with a communication control information of each of the mobile stations according to the broadcast information received by the receiving unit and implements a communication control when a desired receiving level is bidirectionally obtained between the base station and the mobile station. The object is to always ensure a predetermined quality in up and down directional communications.

BACKGROUND OF THE INVENTION 
1) Field of the Invention 
The present invention relates to a mobile communication system for digital 
automobile telephones or the like. Particularly, the present invention 
relate to a mobile communication system for digital automobile telephone 
services, a communication control method for a mobile communication 
system, a base station in a mobile communication system, and a mobile 
station in a mobile communication system. 
2) Description of the Related Art 
In general digital automobile telephone systems, concepts about 
communication level and communication out level have been employed. 
The communication level means a receiving level at which waiting is 
permitted so that the receiving level of each mobile station allows 
communications to a base station without any trouble. 
The communication out level means a receiving level which is judged that a 
mobile station is out of communicable zone when the receiving level of the 
mobile station in communication state is less than a communication out 
level. 
A base station transmits only one communication level and one communication 
out level. If a mobile station has a receiving level more than a 
communication level, it is displayed that the mobile station is in a 
communicable zone, thus performing originating and destination calls. If 
the receiving level is not less than a communication out level, the mobile 
station once entering a communicable zone can perform originating and 
destination calls. If the receiving level is less than a communication out 
level, it is displayed that the mobile station is out of a communicable 
zone so that the originating and destination calls cannot be established. 
In other words, the mobile station within the area for a base station 
depends on only a down receiving level value (or judged only at a down 
receiving level) to judge whether the receiving level is a communication 
level or communication out level level. Hence the up receiving level (the 
receiving level received by a base station while a mobile station 
originates) is not used as a communication control judgment. 
In the current mobile communication systems, it cannot be assured that the 
communication qualities in up and down directions are well-balanced in 
view of system design (line design). The transmission output of a mobile 
station depends on a variety of transportable machine, portable machine, 
and mobile stations. 
Now let us consider that the transmission output of a mobile station is 
considerably smaller than that of the base station. Even if the down link 
(from a base station to a mobile station) has a receiving level sufficient 
in the connection or communication quality, a question in a connection 
quality such as an erroneous connection of an originating signal may occur 
or a question in communication quality such as a bad up-link connection 
may occur, because of the small transmission output of the up link (from 
the mobile station to the base station). 
Let us consider the cases, for example, shown in FIG. 24. When the base 
station has its transmission power of 1.0 W (electric field intensity 30 
dBm: 143 dB.mu.V) and its propagation loss is 135 dB, the receiving level 
of the mobile station is 8 dB.mu.V, thus satisfying the desired quality of 
the down transmission (1). 
In consideration of the up transmission (2) with the transmission output of 
the mobile station of 3.0 W (electric field intensity 34.7 dBm: 147.7 
dB.mu.V), the receiving level of the base station is 12.7 dB.mu.V, whereby 
the desired quality in an up link is satisfied. 
In consideration of the up transmission (3) with the transmission output of 
the mobile station of 2.0 W (electric field intensity 33.0 dBm: 146.0 
dB.mu.V), the receiving level of the base station is 11.0 dB.mu.V, whereby 
the desired quality in an up link is satisfied. 
In consideration of the up transmission (4) with the transmission output of 
the mobile station of 0.8 W (electric field intensity 29.0 dBm: 142.0 
dB.mu.V), the receiving level of the base station is 7.0 dB.mu.V, whereby 
the desired quality in an up link is not satisfied. 
In consideration of the up transmission (5) with the transmission output of 
the mobile station of 0.3 W (electric field intensity 24.7 dBm: 137.7 
dB.mu.V), the receiving level of the base station is 2.7 dB.mu.V, whereby 
the desired quality is not satisfied. 
As described above, there are the case where the transmission output of the 
mobile station side satisfies the quality in an up link and the case where 
the transmission output of the mobile station side does not satisfy the 
quality in an up link. 
Next, the case shown in FIG. 25 is considered. With the transmission output 
of the base station of 3.0 W (electric field intensity 34.7 dBm: 147.7 
dB.mu.V) and the propagation loss of 139.7 dB, the receiving level of the 
mobile station is 8 dB.mu.V, whereby the desired quality in the down 
transmission (6) is satisfied. 
In consideration of the up transmission (7) with the transmission output of 
the mobile station of 3.0 W (electric field intensity 34.7 dBm: 147.7 
dB.mu.V), the receiving level of the base station is 8.0 dB.mu.V, whereby 
the desired quality is satisfied in an up link. 
In consideration of the up transmission (8) with the transmission output of 
the mobile station of 2.0 W (electric field intensity 33.0 dBm: 146.0 
dB.mu.V), the receiving level of the base station is 6.3 dB.mu.E, whereby 
the desired quality is not satisfied in an up link. 
In consideration of the up transmission (9) with the transmission output of 
the mobile station of 0.3 W (electric field intensity 24.7 dBm: 137.7 
dB.mu.V), the receiving level of the base station is -1.9 dB.mu.V, whereby 
the desired quality is not satisfied in an up link. 
As described above, even when the transmission output of the base station 
is as high as 3.0 W, there are the case where the transmission output of 
the mobile station satisfies the quality in up link and the case where the 
transmission output of the mobile station does not satisfy the quality in 
up link. 
SUMMARY OF THE INVENTION 
The present invention is made to overcome the above mentioned problems. An 
object of the present invention is to provide a mobile communication 
system that can ensure always a desired communication quality in up and 
down directions. 
Another object of the present invention is to provide a communication 
control method used in a mobile communication system that can ensure 
always a desired communication quality in up and down directions. 
Still another object of the present invention is to provide a base station 
used in a mobile communication system that can ensure always a desired 
communication quality in up and down directions. 
Further another object of the present invention is to provide a mobile 
station used in a mobile communication system that can ensure always a 
desired communication quality in up and down directions. 
In order to achieve the above objects, according to the present invention, 
the mobile communication system is characterized by a base station and a 
mobile station, the base station including broadcasting means that reports 
information to the mobile station, the information being considered in a 
transmission output difference to the mobile station; the mobile station 
including receiving means that receives the broadcast information reported 
from the broadcasting means of the base station and control means that 
controls with communication control information of each of the mobile 
stations according to the broadcast information received by the receiving 
means and implements a communication control when a desired receiving 
level is bidirectionally obtained between the base station and the mobile 
station. 
According to the present invention, the mobile communication system has a 
simple configuration and can provide the following effect and advantage. 
(1) Good line quality and communication quality can be obtained in the up 
and down directions without depending on the difference in transmission 
output between the base station and the mobile station. This feature 
greatly contributes to improved services in mobile communication systems 
such as digital automobile telephones. 
(2) Even if a current base station is switched by a channel switching and a 
zone shifting, broadcast information is immediately received from a 
switched base station, so that communication control can be performed 
using plural pieces of communication control information according to the 
transmission output after the switching operation, or communication 
control can be performed using a correction value that corrects uniform 
communication control information. Hence good quality can be obtained in 
the up and down directions even when communication is established to any 
base station. 
According to the present invention, the communication control method in a 
mobile communication system including a base station and a mobile station 
is characterized by the steps of controlling communication control 
information in the mobile station, according to a transmission output 
difference between the base station and the mobile station; and 
performing a communication control when a desired receiving level is 
bidirectionally obtained between the base station and the mobile station. 
According to the present invention, the communication control method in the 
mobile communication system has a simple configuration and can provide the 
following effect and advantage. 
(1) Good line quality and communication quality can be obtained in the up 
and down directions without depending on the difference in transmission 
output between the base station and the mobile station. This feature 
greatly contributes to improved services in mobile communication systems 
such as digital automobile telephones. 
(2) Even if a current base station is switched by a channel switching and a 
zone shifting, broadcast information is immediately received from a 
switched base station, so that communication control can be performed 
using plural pieces of communication control information according to the 
transmission output after the switching operation, or communication 
control can be performed using a correction value that corrects uniform 
communication control information. Hence good quality can be obtained in 
the up and down directions even when communication is established to any 
base station. 
Furthermore, according to the present invention, the base station in a 
mobile communication system, the base station including a base station and 
a mobile station, is characterized by broadcasting means for reporting 
information to the mobile station, the information being considered in a 
transmission output difference to the mobile station. 
According to the present invention, the base station in the mobile 
communication system has a simple configuration and can provide the 
following effect and advantage. 
(1) Good line quality and communication quality can be obtained in the up 
and down directions without depending on the difference in transmission 
output between the base station and the mobile station. This feature 
greatly contributes to improved services in mobile communication systems 
such as digital automobile telephones. 
(2) Even if a current base station is switched by a channel switching and a 
zone shifting, broadcast information is immediately received from a 
switched base station, so that communication control can be performed 
using plural pieces of communication control information according to the 
transmission output after the switching operation, or communication 
control can be performed using a correction value that corrects uniform 
communication control information. Hence good quality can be obtained in 
the up and down directions even when communication is established to any 
base station. 
According to the present invention, the mobile station in a mobile 
communication system including a base station and a mobile station is 
characterized by receiving means for receiving broadcast information, in 
which a transmission output difference to the mobile station is 
considered, reported from the base station; and control means for 
controlling with communication control information of each mobile station, 
according to broadcast information received by the receiving means, and 
implementing a communication control when a desired receiving level is 
bidirectionally obtained between the base station and the mobile station. 
According to the present invention, the mobile station in the mobile 
communication system has a simple configuration and can provide the 
following effect and advantage. 
(1) Good line quality and communication quality can be obtained in the up 
and down directions without depending on the difference in transmission 
output between the base station and the mobile station. This feature 
greatly contributes to improved services in mobile communication systems 
such as digital automobile telephones. 
(2) Even if a current base station is switched by a channel switching and a 
zone shifting, broadcast information is immediately received from a 
switched base station, so that communication control can be performed 
using plural pieces of communication control information according to the 
transmission output after the switching operation, or communication 
control can be performed using a correction value that corrects uniform 
communication control information. Hence good quality can be obtained in 
the up and down directions even when communication is established to any 
base station.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
(a) Aspect of Invention 
First an aspect of the present invention will be described below with 
reference to the attached drawings. 
The mobile communication system according to the present invention is 
constructed like the block diagram showing the aspect in FIG. 1. Referring 
to FIG. 1, numeral 1 represents a base station and 2 represents a mobile 
station. 
This mobile communication system includes the base station 1 and the mobile 
station 2. 
Numeral 3 represents broadcasting means. The broadcasting means 3 is 
arranged in the base station 1 to broadcast information considering the 
transmission output difference to the mobile station 2, to the mobile 
station 2. 
Numeral 4 represents receiving means. The receiving means 4 is arranged in 
the mobile station 2 to receive broadcast information reported from the 
broadcasting means 3 in the base station 1. 
Numeral 5 represents control means. The control means 5 controls with 
communication control information from each mobile station 2 according to 
broadcast information received by the receiving means 4 and implements a 
communication control when a predetermined receiving level is 
bidirectionally satisfied between the mobile station 2 and the base 
station 1. 
In the mobile communication system according to the present invention, as 
shown in FIG. 2, the broadcasting means 3(3A) in the base station 1 is 
constituted as means that report plural pieces of communication control 
information according to the transmission output P2 of the mobile station 
2. The mobile station 2 includes selecting means 6(6A) that selects 
communication control information corresponding to the transmission output 
P2 of the self station 2 among plural pieces of communication control 
information sent from the base station 1, and judging means 7 that judges 
whether the self station 2 implements a communication control according to 
the communication control information selected by the selecting means 
6(6A). 
In the mobile communication system according to the present invention, as 
shown in FIG. 3, the base station 1 includes broadcasting means 3(3B) that 
is constituted as means that reports fixed communication control 
information and plural pieces of correction value information H to correct 
communication control information, according to the transmission output P2 
of the mobile station 2; and the mobile station 2 includes control means 
5(5B), the control means 5(5B) includes selecting means 6(6B) that selects 
a correction value HT corresponding to the transmission output P2 of the 
self station 2 among communication control information and plural pieces 
of correction value information H sent from the base station 1, and 
discriminating means 7 that corrects the communication control information 
with the correction value HT selected by the selecting means 6(6B) (this 
correction is made by the correction value calculating unit 8(8B)) and 
then discriminates whether the self station 2 implements a communication 
control according to the corrected communication control information. 
Moreover, in the mobile communication system of the present invention, as 
shown in FIG. 4, the base station 1 includes broadcasting means 3(3C) that 
is constituted as means that reports the information regarding 
transmission output P1 of the base station 1 itself in addition to fixed 
communication control information. In the mobile station 2, the control 
means 5(5C) includes correcting means 8(8C) that calculates a difference 
.DELTA.P between the transmission output P1 of the base station 1 and the 
transmission output P2 of the mobile station 2 itself, based on the 
information regarding the transmission output P1 received by the base 
station 1 (this difference .DELTA.P is calculated by the transmission 
output difference calculating means 13), and then corrects communication 
control information, using the difference .DELTA.P as a correction value 
HT, and discriminating means 7 that discriminates whether the self station 
performs a communication control according to communication control 
information obtained after correction by the correcting means 8(8C). 
In the mobile communication system of the present invention, in the mobile 
station 2, the control means 5(5C) is constituted as means that 
establishes a communication permission on the condition that the receiving 
level of the self station 2 is more than a predetermined communication 
level and the receiving level corrected with the transmission output 
difference .DELTA.P between the transmission output of the base station 1 
and the transmission output of the self station 2 is more than the 
communication level. In the mobile station 2, the control means 5(5C) 
establishes a communication out level on the condition that the receiving 
level corrected with the transmission output difference .DELTA.P between 
the transmission output of the base station 1 and the transmission output 
of the self station 2 is less than the predetermined communication out 
level. 
According to the present invention, the communication control means in a 
mobile communication system includes the following procedures. 
The mobile communication system including the base station 1 and the mobile 
station 2 includes the steps of considering the transmission output 
difference between the base station 1 and the mobile station 2 (procedure 
1), controlling with communication control information from each of the 
mobile station 2 (procedure 2), and performing a communication control 
when a predetermined receiving level is bidirectionally satisfied between 
the mobile station 2 and the base station 1 (procedure 3). 
Furthermore, according to the present invention, the communication control 
means in a mobile communication system includes the following procedures. 
In the base station 1, plural pieces of communication control information 
is reported according to the transmission output P2 of the mobile station 
2 (procedure 4). In the mobile station 2, the communication control 
information corresponding to the transmission output P2 of the self 
station 2 is selected among plural pieces of communication control 
information sent from the base station 1 (procedure 5). It is judged 
whether the self station 2 implements a communication control according to 
the selected communication control information (procedure 6). 
Moreover, according to the present invention, the communication control 
method in a mobile communication system includes the following procedures. 
In the base station 1, fixed communication control information and plural 
pieces of correction value information H for communication control 
information correction are reported according to the transmission output 
P2 from the mobile station 2 (procedure 7). In the mobile station 2, a 
correction value HT corresponding to the transmission output P2 of the 
self station 2 is selected among communication control information 
received from the base station 1 and plural pieces of correction value 
information H (procedure 8). The communication control information is 
corrected with the selected correction value HT to judge whether the self 
station 2 performs a communication control according to the communication 
control information after correction (procedure 9). 
According to the present invention, the communication control method in a 
mobile communication system includes the following procedures. 
In the base station 1, information regarding the transmission output P1 of 
the self station 1 itself is reported together with fixed communication 
control information (procedure 10). In the mobile station 2, the 
difference .DELTA.P between the transmission output Pi of the base station 
1 and the transmission output P2 of the mobile station 2 is calculated 
based on the information regarding the transmission output P1 sent from 
the base station 1 (procedure 11). The communication control information 
is corrected using the difference .DELTA.P as a correction value 
(procedure 12). It is judged whether the self station 2 performs the 
communication control according to the communication control information 
after correction (procedure 13). 
According to the present invention, the communication control method in a 
mobile communication system includes the following procedures. 
The mobile station 2 establishes communication permission on the condition 
that the receiving level of the self station 2 is more than a 
predetermined communication level and the receiving level corrected with 
the transmission output difference .DELTA.P between the transmission 
output of the base station 1 and the transmission output of the self 
station 2 is more than the communication level (procedure 14). 
In the mobile station 2, a communication out level is established on the 
condition that the receiving level corrected with the transmission output 
difference .DELTA.P between the base station 1 and the self station 2 is 
less than a predetermined communication out level level (procedure 15). 
According to the present invention, as shown in FIG. 2, in a mobile 
communication system including the base station 1 and the mobile station 
2, the broadcasting means 3 arranged in the base station 1 reports 
information considering the transmission output difference to the mobile 
station 2, to the mobile station 2. The receiving means 4 arranged in the 
mobile station 2 receives broadcast information sent from the broadcasting 
means 3 in the base station 1. The control means 5 controls with 
communication control information according to the transmission output of 
the mobile station 2. Thus a communication control is performed when a 
predetermined receiving level is bidirectionally satisfied between the 
mobile station 2 and the base station 1. 
According to the present invention, in the mobile communication system, as 
shown in FIG. 2, the broadcasting means 3(3A) in the base station 1 
reports plural pieces of communication control information according to 
the transmission output P2 of the mobile station 2. In the control means 
5(5A) in the mobile station 2, the selecting means 6(6A) selects 
communication control information corresponding to the transmission output 
P2 of the self station 2 itself among plural pieces of communication 
control information sent from the base station 1. The discriminating means 
7 discriminates whether the self station 2 performs a communication 
control according to the communication control information selected by the 
selecting means 6(6A). 
In the mobile communication system according to the present invention, as 
shown in FIG. 3, the broadcasting means 3(3B) in the base station 1 
reports fixed communication control information and plural pieces of 
correction value information H for communication control information 
correction according to the transmission output P2 of the mobile station 
2. In the control means 5(5B) in the mobile station 2, the selecting means 
6(6B) selects the correction value HT corresponding to the transmission 
output P2 of the self station 2 among communication control information 
and plural pieces of correction value information H sent from the base 
station 1, and then corrects the communication control information using 
the selected correction value HT. The discriminating means 7 discriminates 
whether the self station 2 performs a communication control according to 
the corrected communication control information. 
Moreover, in the mobile communication system according to the present 
invention, as shown in FIG. 4, the broadcasting means 3(3C) in the base 
station 1 reports information regarding the transmission output P1 of the 
base station 1 itself in addition to fixed communication control 
information. In the mobile station 2, the control means 5(5C) calculates 
the difference .DELTA.P between the transmission output P1 of the base 
station 1 and the transmission output P2 of the mobile station 2 itself, 
based on the information regarding the transmission output P1 of the base 
station 1. The correcting means 8(8C) corrects the communication control 
information using the difference .DELTA.P as a correction value HT. The 
discriminating means 7 discriminates whether the self station performs a 
communication control according to the communication control information 
corrected by the correcting means 8(8C). 
In the mobile communication system of the present invention, as shown in 
FIG. 4, the control means 5(5C) in the mobile station 2 judges a 
communication state on the condition that the receiving level of the self 
station 2 is more than a predetermined communication level and the 
receiving level corrected with the difference .DELTA.P in transmission 
output between the base station 1 and the self station 2 is more than the 
communication level. The control means 5(5C) in the mobile station 2 also 
judges a communication inhibition state on the condition that the 
receiving level of the self station 2 corrected with the difference 
.DELTA.P in transmission output between the base station 1 and the self 
station 2 is less than the communication out level level. 
In the communication control method in a mobile communication system 
according to the present invention, the configuration shown in FIG. 2 
operates according to the following procedures. First, in the mobile 
communication system including the base station 1 and the mobile station 
2, where a predetermined receiving level is bidirectionally satisfied for 
the base station 1 and the mobile station 2 by considering the 
transmission output difference between the base station 1 and the mobile 
station 2 and controlling it with the communication control information 
from each mobile station 2, a communication control is performed. 
In the communication control method in a mobile communication system, the 
configuration shown in FIG. 2 operates according to the following 
procedures. That is, in the base station 1, plural pieces of communication 
control information are reported according to the transmission output P2 
of the mobile station 2. In the mobile station 2, communication control 
information corresponding to the transmission output P2 of the self 
station 2 is selected among plural pieces of communication control 
information sent by the base station 1 and then it is discriminated 
whether the self station 2 perform the communication control according to 
the selected communication control information. 
Furthermore, in the communication control method in a mobile communication 
system, the configuration shown in FIG. 3 operates according to the 
following procedures. That is, in the base station 1, fixed communication 
control information and plural pieces of correction value information H 
for a communication control information correction are reported according 
to the transmission output P2 of the mobile station 2. In the mobile 
station 2, the correction value HT corresponding to the transmission 
output P2 of the self station 2 is selected according to the communication 
control information and plural pieces of correction value information H 
received from the base station 1. The communication control information is 
corrected with the selected correction value HT. It is discriminated 
whether the self station 2 performs a communication control according to 
the corrected communication control information. 
In the communication control method in a mobile communication system of the 
present invention, the configuration shown in FIG. 4 operates according to 
the following procedures. That is, in the base station 1, information 
regarding the transmission output P1 of the base station 1 itself 
according to the transmission output P2 from the mobile station 2, in 
addition to fixed communication control information, is reported. In the 
mobile station 2, the difference .DELTA.P between the transmission output 
P1 of the base station 1 and the transmission output P2 of the mobile 
station 2 itself is calculated based on the information regarding the 
transmission output P1 of the base station 1. The communication control 
information is corrected using the difference .DELTA.P as a correction 
value. It is discriminated whether the self station 2 performs a 
communication control according to the communication control information 
after correction. 
In the communication control method in a mobile communication system of the 
present invention, the configuration shown in FIG. 4 operates according to 
the following procedures. That is, in the mobile station 2, where the 
receiving level of the self station 2 is more than a predetermined 
communication level and the receiving level corrected with the 
transmission output difference .DELTA.P between the base station 1 and the 
self station 2 is more than the communication level, the communication 
permission state is established. 
Furthermore, in the communication control method in a mobile communication 
system of the present invention, the configuration shown in FIG. 4 
operates according to the following procedures. That is, in the mobile 
station 2, where the receiving level corrected with the transmission 
output difference .DELTA.P between the base station 1 and the self station 
2 is less than a predetermined degradation level, the communication out 
level state is established. 
As described above, according to the mobile communication system of the 
present invention shown with FIG. 1, the mobile communication system 
includes the base station 1 and the mobile station 2. The base station 1 
includes broadcasting means 3 that reports information considering the 
transmission output difference to the mobile station 2, to the mobile 
station 2. The mobile station 2 includes receiving means 4 that receives 
broadcast information reported from the broadcasting means 3 in the base 
station 1, and the control means 5 that controls with the communication 
control information for each mobile station 2 according to the broadcast 
information received by the receiving means 4 and performs a communication 
control when a predetermined receiving levels is bidirectionally satisfied 
between the mobile station 2 and the base station 1. This simplified 
configuration has the following effects or advantages. 
(1) The line quality and communication quality can be improved in the 
directions of the up/down streams without depending on the difference in 
transmission output between the base station 1 and the mobile station 2. 
Hence, this feature leads to greatly-improved services in mobile 
communication systems such as digital automobile telephones. 
(2) Even if the base station 1 is changed due to a channel switching, a 
zone changing, or the like, the broadcast information from the base 
station 1 is quickly received after the switching operation so that a 
communication control can be performed according to the plural pieces of 
communication control information according to the transmission output 
after the switching operation or a correction value for uniform 
communication control information correction. Hence in communications to 
any base station 1, good quality can be obtained in up and down 
directions. 
According to the embodiments of the mobile communication system of the 
present invention shown in FIG. 2, in the above-mentioned invention, the 
broadcasting means 3(3A) in the base station 1 is constituted as means 
that reports plural pieces of communication control information according 
to the transmission output of the mobile station 2. In the mobile station 
2, the control means 5(5A) includes the selecting means 6(6A) that selects 
communication control information corresponding to the transmission output 
of the self station 2 among plural pieces of communication control 
information sent from the base station 1 and the discriminating means 7 
that discriminates whether the self station 2 performs a communication 
control according to the communication control information selected by the 
selecting means 6(6A). This simplified configuration can provide the 
following effects or advantages, in addition to the effects of the 
above-mentioned invention. 
(3) The communication control information corresponding to the transmission 
output of the self station 2 can be easily selected among plural pieces of 
communication control information sent from the base station 1. 
Moreover, according to the embodiment of the mobile communication system of 
the present invention shown in FIG. 3 in the invention shown with FIG. 1, 
the broadcasting means 3(3B) in the base station 1 is constituted as means 
that reports fixed communication control information and plural pieces of 
correction value information to correct the communication control 
information, according to the transmission output of the mobile station 2. 
In the mobile station 2, the control means 5(5B) includes the selecting 
means 6(6B) that selects the correction value corresponding to the 
transmission output of the self station 2 among communication control 
information and plural pieces of correction value information sent from 
the base station 1, and the discriminating means 7 that corrects the 
communication control information according to the correction value 
selected by the selecting means 6(6B) and discriminates whether the 
self-station 2 performs a communication control according to the 
communication control information after the correction. This compact 
configuration can provide the following effects or advantages, in addition 
to the effects of the invention described with FIG. 1. 
(4) The correction value corresponding to the transmission output of the 
self station 2 is selected, based on plural pieces of correction value 
information received from the base station 1. Thus the communication 
control information can be easily corrected by the selected correction 
value. 
According to the mobile communication system of the present invention 
described with FIG. 4, in the invention shown in FIG. 1, the broadcasting 
means 3(3C) in the base station 1 is constituted as means that reports 
transmission output information of the base station 1 itself in addition 
to fixed communication control information, according to the transmission 
output of the mobile station 2. In the mobile station 2, the control means 
5(5C) includes the correcting means 8(8C) that calculates the difference 
between the transmission output of the base station 1 and the transmission 
output of the mobile station 2, based on the transmission output 
information sent from the base station 1 and then corrects the 
communication control information using the difference as a correction 
value, and the discriminating means 7 that discriminates whether the 
self-station 2 performs a communication control according to the corrected 
value obtained by the correcting means 8(8C). This compact configuration 
can provide the following effects or advantages, in addition to the 
effects of the invention described with FIG. 1. 
(5) The communication control corresponding to the transmission output of 
the self station 2 can be surely discriminated by calculating the 
difference between the transmission output of the base station 1 and the 
transmission output of the mobile station 2 itself and then correcting the 
communication control information using the difference value as a 
correction value. 
According to the mobile communication system of the present invention, in 
the invention shown in FIG. 4, the control means 5(5C) in the mobile 
station 2 establishes a communication permission when the receiving level 
of the self station 2 is higher than a predetermined communication level 
and the receiving level corrected with the transmission output difference 
between the base station 1 and the self station 2 is higher than the 
communication level. This simple configuration can surely decide 
communication permission, in addition to the effects of the invention 
described with FIG. 3. 
Moreover, according to the mobile communication system of the present 
invention, in the invention shown in FIG. 4, the control means 5(5C) in 
the mobile station 2 inhibits waiting when the receiving level corrected 
with the transmission output difference between the base station 1 and the 
self station 2 is lower than a predetermined communication out level 
level. This simplified configuration can certainly provide a communication 
permission judgment, in addition to the effect of the invention defined in 
claim 4. 
According to the communication control method in a mobile communication 
system shown in FIG. 2, the mobile communication system with the base 
station 1 and the mobile station 2 can control the communication control 
information in the mobile station 2 according to the transmission output 
difference between the base station 1 and the mobile station 2. Hence this 
simple configuration, by which a communication control can be performed 
when a predetermined receiving level can be bidirectionally obtained 
between the mobile station 2 and the base station 1, can provide the 
following effects and advantages. 
(6) Excellent line quality and communication quality can be established in 
up and down directions without depending on the transmission output 
difference between the base station 1 and the mobile station 2. Thus this 
feature greatly contributes to improved services in the mobile 
communication system such as digital automobile telephones. 
(7) Even if the base station 1 is changed due to a channel switching and 
zone shifting operation, the broadcast information is quickly received 
from the switched base station 1. Thus a communication control can be 
performed with plural pieces of communication control information 
according to the transmission output after switching or a correction value 
to correct uniform communication control information. Hence in 
communications to any base station 1, good quality can be obtained in up 
and down directions. 
According to the communication control method in a mobile communication 
system of the present invention shown in FIG. 2, the base station 1 
reports plural pieces of communication control information according to 
the transmission output of the mobile station 2. The mobile station 2 
selects the communication control information corresponding to the 
transmission output of the self station 2 among plural pieces of 
communication control information sent from the base station 1 and 
discriminates whether the self station 2 performs a communication control 
according to the selected communication control information. This 
simplified configuration can provide the following effects and advantages, 
in addition to the above-mentioned effects of the invention. 
(8) The communication control information corresponding to the transmission 
output of the self station 2 can be easily selected among plural pieces of 
communication control information sent from the base station 1. 
According to the communication control method in a mobile communication 
system shown in FIG. 3, the base station 1 reports fixed communication 
control information and plural pieces of correction value information to 
correct the communication control information. The mobile station 2 
selects a correction value corresponding to the transmission output of the 
self station 2 among plural pieces of correction value information and 
communication control information sent from the base station 1, corrects 
the communication control information using the selected correction value, 
and discriminates whether the self station 2 performs a communication 
control according to the corrected communication control information. This 
simple configuration can provide the following effects and advantages, in 
addition to the above-described effects of the invention. 
(9) A correction value corresponding to the transmission output of the self 
station 2 is selected among plural pieces of correction value information 
sent from the base station 1. The communication control information can be 
easily corrected with the selected correction value. 
Furthermore, according to the communication control method in a mobile 
communication system of the invention shown in FIG. 3, the base station 1 
reports transmission output information of the self station 1 itself, in 
addition to the fixed communication control information. The mobile 
station 2 calculates the difference between the transmission output of the 
base station 1 and the transmission output of the mobile station 2 itself 
among the transmission output information sent from the base station 1, 
corrects the communication control information using the difference value 
as a correction value, and discriminates whether the self station 2 
performs a communication control using the corrected communication control 
information. This simple configuration can provide the following effects 
and advantages, in addition to the above-mentioned effect of the 
invention. 
(10) The communication control corresponding to the transmission of the 
self station 2 can be surely discriminated by calculating the difference 
between the transmission output of the base station 1 and the transmission 
output of the mobile station 2 itself and correcting the communication 
control information using the difference value as a correction value. 
According to the communication control method in a mobile communication 
system of the invention shown in FIG. 3, where the receiving level of the 
self station 2 is more than a predetermined communication level and the 
receiving level corrected with the transmission output difference between 
the base station 1 and the self station 2 is higher than a predetermined 
communication level, the mobile station 2 becomes communication 
permission. Hence a communication permission judgment can be surely 
performed. 
According to the communication control method in a mobile communication 
system of the present invention, where the receiving level corrected with 
the transmission output difference between the base station 1 and the self 
station 2 is less than a predetermined communication out level level, the 
mobile station 2 becomes communication out level. Hence communication 
permission can be surely judged. 
According to the base station 1 in a mobile communication system of the 
invention shown in FIG. 1, in the mobile communication system including 
the base station 1 and the mobile station 2, the base station 1 includes 
the broadcasting means 3 that reports information considering the 
transmission output difference to the mobile station 2 to the mobile 
station 2. This simple configuration provides the following effect and 
advantage. 
(11) The line quality and the communication quality are excellent in the up 
and down directions without depending on the difference in transmission 
output between the base station 1 and the mobile station 2. This feature 
leads to greatly-improved services in a mobile communication system such 
as digital automobile telephones. 
(12) Even if the base station 1 is changed due to the channel switching and 
zone shift, the broadcast information can be quickly received from the 
changed base station 1. Since the communication control can be performed 
with a correction value that corrects plural pieces of communication 
control information or uniform communication control information 
corresponding to the transmission output after the changing operation, 
good quality can be obtained in up and down directions at the time of 
communications to any base station 1. 
Moreover, according to the base station 1 in a mobile communication system 
described with FIG. 2, the broadcasting means 3(3A) is constituted as 
means that reports plural pieces of communication control information 
according to the transmission output of the mobile station 2. This simple 
configuration provides the following effects and advantages, in addition 
to the above-mentioned effects of the invention. 
(13) Communication control information corresponding to the transmission 
output of the self station 2 can be easily selected among plural pieces of 
communication control information sent from the base station 1. 
According to the base station 1 in a mobile communication system described 
with FIG. 3, the broadcasting means 3(3B) is formed as means that reports 
fixed communication control information and plural pieces of correction 
value information for correcting the communication control information, 
according to the transmission output of the mobile station 2. This compact 
configuration provides the following effect and advantage, in addition to 
the above-mentioned effects of the invention. 
(14) A correction value corresponding to the transmission output of the 
self station 2 can be selected among plural pieces of correction value 
information sent from the base station 1. Hence the communication control 
information can be easily corrected using the selected correction value. 
According to the base station 1 in a mobile communication system described 
with FIG. 4, the broadcasting means 3(3C) is constituted as means that 
reports transmission output information of the base station 1 itself, in 
addition to the fixed communication control information. This simple 
configuration provides the following effect and advantage, in addition to 
the above-mentioned effects of the invention. 
(15) The communication permission corresponding to the transmission output 
of the self station 2 can be surely judged by calculating the difference 
between the transmission output of the base station 1 and the transmission 
output of the mobile station 2 itself and then correcting the 
communication control information using the difference value as a 
correction value. 
Furthermore, according to the mobile station 2 in a mobile communication 
system described with FIG. 1, the mobile station 2 in the mobile 
communication system including the base station 1 and the mobile station 2 
includes receiving means 4 that receives broadcast information reported 
from the base station 1, information considering the transmission output 
difference to the mobile station 2, and the control means 5 that controls 
with communication control information to each mobile station 2 according 
to the broadcast information received by the receiving means 4 and 
performs a communication control when a predetermined receiving level is 
obtained bidirectionally between the mobile station 2 and the base station 
1. This simple configuration can provide the following effect and 
advantage. 
(16) The good line and communication quality can be obtained in up and down 
directions without depending on the difference in transmission output 
between the base station 1 and the mobile station 2. This feature greatly 
contributes to improved services in the mobile communication systems such 
as digital automobile telephones. 
(17) Even if the base station 1 is changed due to the channel switching and 
zone shift, the broadcast information can be quickly received from the 
changed base station 1. Since the communication control can be performed 
with a correction value that corrects plural pieces of communication 
control information or uniform communication control information 
corresponding to the transmission output after the changing operation, 
good quality can be obtained in up and down directions at the time of 
communications to any base station 1. 
According to the mobile station 2 in a mobile communication system of the 
invention described with FIG. 2, the control means 5(5A) includes 
selecting means 6(6A) that selects the communication control information 
corresponding to the transmission output of the self station 2 among 
plural pieces of communication control information sent from the base 
station 1, and discriminating means 7 that discriminates whether the self 
station 2 performs a communication control according to the communication 
control information selected by the selecting means 6(6A). This simple 
configuration can provide the following effect and advantage, in addition 
to the above-mentioned effects of the invention. 
(18) The communication control information corresponding to the 
transmission output of the self station 2 can be easily selected among 
plural pieces of communication control information sent from the base 
station 1. 
According to the mobile station 2 in a mobile communication system 
described in FIG. 3, the control means 5(5B) includes selecting means 
6(6B) that selects a correction value corresponding to the transmission 
output of the self station 2 among communication control information and 
plural pieces of correction value information sent from the base station 
1, and discriminating means 7 that corrects the communication control 
information using the correction value selected by the selecting means 
6(6B) and discriminates whether the self station 2 performs a 
communication control according to the communication control information 
after the correction. This simple configuration can provide the following 
effect and advantage, in addition to the above-mentioned effects of the 
invention. 
(19) A correction value corresponding to the transmission output of the 
self station 2 can be easily selected among plural pieces of correction 
value information sent from the base station 1. Hence the communication 
control information can be corrected using the selected correction value. 
According to the mobile station 2 in a mobile communication system of the 
present invention described with FIG. 4, the control means 5(5C) includes 
correcting means 8(8C) that calculates the difference between the 
transmission output of the base station 1 and the transmission output of 
the mobile station 2 itself by the transmission output information sent 
from the base station 1 and then corrects the communication control 
information using the difference value as a correction value, and 
discriminating means 7 that discriminates whether the self station 2 
performs a communication control according to the corrected communication 
control information obtained by the correcting means 8(8C). This simple 
configuration can provide the following effect and advantage, in addition 
to the above-mentioned effects of the invention. 
(20) The communication control corresponding to the transmission output of 
the self station 2 can be surely judged by calculating the difference 
between the transmission output of the base station 1 and the transmission 
output of the mobile station 2 itself and then correcting the 
communication control information using the difference value as a 
correction value. 
According to the mobile station 2 in a mobile communication system of the 
invention described with FIG. 4, the control means 5(5C) is constituted as 
means that permits waiting when the receiving level of the self station 2 
is more than a predetermined communication level and the receiving level 
corrected with the transmission output difference between the base station 
1 and the self station 2 is more than the communication level and the 
judgement of the transmission permission is surely performed. 
According to the mobile station 2 in a mobile communication system of the 
invention described above, the control means 5(5C) inhibits waiting when 
the receiving level corrected with the transmission output difference 
between the base station 1 and the self station 2 is less than a 
predetermined communication out level level. Hence the communication 
permission can be certainly judged. 
(b) An Embodiment of the Present Invention 
Next an embodiment according to the present invention will be described 
below with reference to the attached drawings. 
FIG. 5 is a block diagram showing an embodiment of the present invention. 
Referring to FIG. 5, numeral 1 represents a base station and 2 represents 
a mobile station. The mobile communication system includes the base 
station 1 and the mobile station 2. 
Numeral 3(3A) represents a reporting unit. The reporting unit 3(3A) is 
arranged in the base station 1 to broadcast information considering the 
transmission output difference to the mobile station 2, to the mobile 
station 2. 
Numeral 4 represents a receiving unit. The receiving unit 4 is arranged in 
the mobile station 2 to receive broadcast information reported from the 
reporting unit 3 in the base station 1. 
Numeral 5(5A) represents a control unit. The control unit 5(5A) controls 
with the communication level KL and the communication out level RL 
(communication control information) to each mobile station 2 according to 
the broadcast information received by the receiving unit 4, and 
communication control is performed when a predetermined receiving level 
about up and down directions of the mobile station 2 and the base station 
1 is sufficient. 
The reporting unit 3(3A) in the base station 1 is constituted as means that 
reports plural pieces of information regarding communication level KL and 
plural pieces of information regarding communication out level level RL, 
corresponding to the transmission output P2 of the mobile station 2. 
Numeral 6(6A) represents a selecting unit. The selecting unit 6(6A) selects 
the communication level KL and communication out level level RL 
corresponding to the transmission output P2 of the self station 2 among 
plural pieces of information regarding communication level KL and 
communication out level level RL sent from the base station 1, and then 
outputs them to the control unit 5(5A). 
Numeral 7 represents a discriminating unit. The discriminating unit 7 is 
arranged to the control unit 5(5A) to discriminate whether the self 
station 2 performs a communication control at the communication level KL 
and communication out level level RL each selected by the selecting unit 
6(6A). 
Numeral 11 represents a receiving level detecting unit. The receiving level 
detecting unit 11 detects a signal level received by the receiving unit 4. 
The broadcast information reported from the reporting unit 3 in the base 
station 1 to the mobile station 2 is constituted as the schematic diagram 
shown in FIG. 9 or 10. 
That is, the broadcast information is formed with value each pieces of data 
(shown in the figures) arranged at allocated bit locations. Each of pieces 
of data includes the following content. 
(a) Message classification 
(b) Network number 
(c) Regulation information 
(d) Control channel structure information 
(e) Mobile station transmission power designation 
(f) Communication level classified by transmission output of mobile station 
(g) Communication out level level classified by transmission output of 
mobile station 
(h) Position registration area muliplex number 
(i) Location number 
(j) The number of maximum report channels 
(k) Perch channel number for communicable zone/sector decision 
(l) Perch channel number 
(m) Location registration timer 
(n) Extended information factor length 
(o) Extended information factor 
In the broadcast information, with the transmission output P1 of the base 
station 1 being, for example, 1 W, as (f) the communication level KL 
classified by the transmission output of a mobile station, as shown in 
FIG. 9, the following plural values corresponding to the output P2 of the 
mobile station 2 are included. 
With the output P2 of the mobile station 2 being 3 W, the communication 
level KL is set to 8 dB.mu.V. 
With the output P2 of the mobile station 2 being 2 W, the communication 
level KL is set to 8 dB.mu.V. 
With the output P2 of the mobile station 2 being 0.8 W, the communication 
level KL is set to 9 dB.mu.V. 
With the output P2 of the mobile station 2 being 0.3 W, the communication 
level KL is set to 13.3 dB.mu.V. 
In the broadcast information, as (g) the communication out level level RL 
classified by the transmission output of a mobile station the following 
plural values corresponding to the output P2 of the mobile station 2 are 
included. 
With the output P2 of the mobile station 2 being 3 W, the communication out 
level level RL is set to 2 dB.mu.V. 
With the output P2 of the mobile station 2 being 2 W, the communication out 
level level RL is set to 2 dB.mu.V. 
With the output P2 of the mobile station 2 being 0.8 W, the communication 
out level level RL is set to 3 dB.mu.V. 
With the output P2 of the mobile station 2 being 0.3 W, the communication 
out level level RL is set to 7.3 dB.mu.V. 
Moreover, in the broadcast information, with the transmission output P1 of 
the base station 1 being, for example, 3 W, as (f) the communication out 
level level RL classified by the transmission output of a mobile station, 
as shown in FIG. 10, the following plural values corresponding to the 
output P2 of the mobile station 2 are included. 
With the output P2 of the mobile station 2 being 3 W, the communication 
level KL is set to 8 dB.mu.V. 
With the output P2 of the mobile station 2 being 2 W, the communication 
level KL is set to 9.7 dB.mu.V. 
With the output P2 of the mobile station 2 being 0.8 W, the communication 
level KL is set to 13.7 dB.mu.V. 
With the output P2 of the mobile station 2 being 0.3 W, the communication 
level KL is set to 18.0 dB.mu.V. 
In the broadcast information, as (g) the communication out level level RL 
classified by the transmission output of a mobile station the following 
plural values corresponding to the output P2 of the mobile station 2 are 
included. 
With the output P2 of the mobile station 2 being 3 W, the communication out 
level level RL is set to 2 dB.mu.V. 
With the output P2 of the mobile station 2 being 2 W, the communication out 
level level RL is set to 3.7 dB.mu.V. 
With the output P2 of the mobile station 2 being 0.8 W, the communication 
out level level RL is set to 7.7 dB.mu.V. 
With the output P2 of the mobile station 2 being 0.3 W, the communication 
out level level RL is set to 12.0 dB.mu.V. 
The mobile station 2 has the hardware configuration as shown in the block 
diagram in FIG. 8. 
Numerals 114 and 115 represent antennas in FIG. 8. The communication radio 
wave is transmitted and received through the antenna 114 and the 
transmit/receive hybrid circuit 101. The antenna 115 receives the radio 
wave. 
Numerals 110 and 111 represent receivers. The radio waves received with the 
antenna 114 and 115 are input to the receiver 110 and 111, respectively. 
After the receiving operation such as detection is performed with the 
local oscillation output from the high-speed switching synthesizer 105, 
this radio wave is input to the demodulator 112. 
The demodulator 112 demodulates a better one of the outputs from the 
receivers 110 and 111. This operation is performed the so-called diversity 
reception. 
Numeral 106 represents a TDMA (Time division multiple access) circuit. The 
TDMA circuit 106 receives a demodulation signal from the demodulator 112 
and then releases its timesharing state, thus extracting desired data. 
Numeral 107 represents a CODEC (coder-decoder). The CODEC 107 receives an 
output signal from the TDMA circuit 106 to convert it into an analog 
signal, thus producing a voice signal through a loud speaker 109. 
The CODEC 107 is applied to the transmission system. The CODEC 107 converts 
an output from the microphone 108 into a digital signal, thus producing it 
to the TDMA circuit 106. 
Furthermore, the TDMA circuit 106 as well is constituted so as to be 
applicable to the transmission system. The TDMA circuit 106 is constituted 
such that it receives an output from the CODEC 107, performs a desired 
time-sharing process, and then inputs the serial data to the wave shaper 
104. 
The wave shaper 104 subjects an output from the TDMA circuit 106 to a 
desired wave shaping process. 
Numeral 103 represents a RF band orthogonal modulator. The RF band 
orthogonal modulator 103 modulates an input from the wave shaper 104 into 
a signal in a desired RF band using the output of the high-speed switching 
synthesizer 105 and then outputs the resultant signal. 
Numeral 102 represents a power amplifier. The power amplifier 102 receives 
a signal in a RF band from the RF band orthogonal modulator 103 and 
high-frequency amplifies a signal to a desired output. Then the resultant 
signal is transmitted out of the antenna 114 via the transmit/receive 
hybrid circuit 101. 
Numeral 116 represents a CPU (Central processing unit). The CPU 116 has the 
functions of a control unit 5(5A), a selecting unit 6(6A), and a 
correction value calculating unit 8. In response to the output from the 
TDMA circuit 106, the CPU 116 implements various processes described 
above, thus producing a desired control output. 
Numeral 113 is a display operation unit. The display operation unit 113 
receives the output from the CPU 116 and displays, for example, "in 
communication permission state". 
In the above-mentioned configuration, the mobile station 2 according to the 
present embodiment operates according to the flowchart shown in FIG. 14. 
Power is first turned on (step S1) and then the perch frequency is set 
(step S2). 
The perch frequency is set to a specific one among plural kinds of 
communication frequency channels in the mobile station 2 as a candidate 
for communications. Every time the step S2 is implemented, different 
frequencies are employed as candidates in prescribed order. 
The receiving level L1 of the receiver 4 set to at a perch frequency is 
measured in the step S3 to judge whether the receiving level L1 exceeds 
the threshold level Lth1 (step S4). 
The threshold level Lth1 is set to a level at which normal communications 
is hardly expected, or to a lower level than the communication level KL or 
communication out level level RL. 
If the receiving level L1 exceeds the threshold level Lth1, the perch 
channel and the receiving level of the perch channel are written into a 
memory via the "YES" route (step S5). 
Thereafter, it is judged whether all perch channels have been subjected to 
an examination operation in the steps S2 to S5 (step S6). If there are 
channels unexamined, examination is performed from the step S2 via the 
"NO" route. This process is repeated till all the perch channels have been 
completely examined. 
When all the perch channels have been completely examined, it is judged in 
the step S7 whether the perch channel has been written into the memory in 
the step S5. In the case of no writing operation, the receiving levels L1 
of each of all the channels are less than the threshold level Lth1. Since 
it is judged via the NO route that the communications is impossible, the 
process (display) for regions out of a communicable zone is performed 
(step S15). Hence any communication cannot be performed. 
Where it is judged that writing has been completed in the step S7, 
communicable channels may exist. For the corresponding channels, a table 
on which the receiving levels are listed in decreasing order is prepared 
(step S8). 
Next, a communication channel is set to the perch channel on the top of the 
table prepared in the step S8 (step S9). 
The receiving level L2 of the channel is detected (step S10) while the 
broadcast information is received. 
The broadcast information includes the content shown in FIG. 21. The 
operation along the flowchart shown in FIG. 20 will be described in detail 
later. 
Next, it is judged in the step S11 (step A1) whether receiving the 
broadcast information has been completed. At the completion, the step S12 
is performed via the "YES" route. 
In the step S12, it is judged whether the receiving level L2 exceeds the 
communication level Lth2 classified by the mobile station transmission 
output as the communication level KL. If yes, the corresponding channel is 
communicable. Hence the discriminating unit 7 discriminates a 
communication permission (step S13). 
On the other hand, where the receiving level L2 does not exceed the 
communication level Lth2 classified by the transmission output of a mobile 
station, the step S14 is implemented via the "NO" route. 
Plural communication levels Lth2 classified by the transmission output of a 
mobile station are set as shown in FIG. 20. The level corresponding to the 
transmission output P2 is adopted. 
It is judged whether the channel in examination is the last channel in the 
step S14. If the corresponding channel is not the last channel in the 
prepared table in the step S8, the next candidate channel is subjected to 
the process from the step S9 via the "NO" route. 
Where the last channel has been completely examined, channels having 
possible communicable states do not exist. Hence the process (display) for 
regions out of a communicable zone is performed via the "YES" route in the 
step S15 and the communication cannot be performed. 
The communication permission (step S13) is performed by implementing each 
of the steps in the flowchart regarding the communication permission. 
After the communication state, various operations are implemented 
according to the flowchart shown in FIG. 17. 
That is, the receiving level L2 of the mobile station 2 is detected every 
predetermined time (step S16). 
Every time the receiving level is detected, it is judged whether the 
receiving level L2 exceeds the communication out level level Lth2' 
classified by the transmission output of a mobile station as a 
communication out level level RL (step S18). Where the excessive state 
continues, the waiting condition is satisfied. Hence the process from the 
step S16 via the "YES" route, or so-called communication condition 
monitoring, is continuously repeated. 
In the step S18, where it is judged that the receiving level L2 does not 
exceed the communication out level level Lth2' classified by the 
transmission output of the mobile station, the process (display) for 
regions out of a communicable zone is performed (step S15) because of no 
communication condition obtained. Hence the communications cannot be 
established. 
In such a manner, the corresponding operation is performed to a change in 
status after the establishment of the communication condition so that the 
communication condition establishing status can be ensured at a 
communication time. 
When the CPU 116 selects control information corresponding to the 
self-station transmission output P2, the selecting unit 6(6A) implements 
the operation according to the flowchart shown in FIG. 20. 
That is, after recognition of the self-station transmission output P2, a 
judgment operation is performed in the step S19. 
If the 3 W output mobile station 2 is recognized, the table "1" is referred 
through the "YES" route in the step S20. 
The communication state (step S13) comes by performing a control with 
communication control information in the table "1" (step S21). 
If the 2 W output mobile station 2 is recognized, the step S23 is executed 
via the "NO" route from the step S19 and then the table "2" is referred 
through the "YES" route in the step S24. 
The control operation is performed according to the communication control 
information in the table "2" (step S25) and then the mobile station 2 
reaches to a communication state (step S13). 
If the 0.8 W output mobile station 2 is recognized, the step S26 is 
executed via the "NO" route in the step S23. Then the table "3" is 
referred through the "YES" route in the step S27. 
The control operation is performed according to the communication control 
information in the table "3" (step S28), and then the mobile station 2 
reaches to a communication state (step S13). 
If the 0.3 W output mobile station 2 is recognized, the step S29 is 
executed via the "NO" route in the step S26. Then the table "4" is 
referred through the "YES" route in the step S30. 
The control operation is performed according to the communication control 
information in the table "4" (step S31), and then the mobile station 2 
reaches to a communication state (step S13). 
The tables "1" to "4" store readably the communication level Lth2 and the 
communication out level level Lth2' each corresponding to the output P2 of 
each mobile station 2 shown in FIG. 21. 
As described above, the control is performed using each of the level values 
Lth2 and Lth2'. The communication permission release judging control is 
performed using each degradation level. 
Such control operations enable each prescribed transmit/receive quality 
shown in FIGS. 22 and 23. 
Let us consider 1 W output base station 1, comparing with the general 
example shown in FIG. 24. 
The communication level KL (Lth2) and the communication out level level RL 
(Lth2') have the values shown in FIG. 9, respectively. 
Referring to FIG. 22, when the transmission output (1a) of the base station 
1 is 143 dB.mu.V, the receiving level of the 3 W mobile station 2 is 8 
dB.mu.V, under the propagation loss of 135 dB. 
The communication level Lth2, as shown in FIG. 9, is 8 dB.mu.V. The 
permission discrimination allows the transmission output (2') from the 
mobile station 2. 
If the transmission output (2') is 147.7 dB.mu.V, the receiving level of 
the base station 1 is 12.7 dB.mu.V, thus satisfying the predetermined 
quality. 
When the transmission output (1b) of the base station 1 is 143 dB.mu.V, the 
receiving level of the 2 W mobile station 2 is 8 dB.mu.V, under the 
propagation loss of 135 dB. 
The communication level Lth2, as shown in FIG. 9, is 8 dB.mu.V. According 
to the permission discrimination, the mobile station 2 produces the 
transmission output (3'). 
If the transmission output (3') is 146.0 dB.mu.V, the receiving level of 
the base station 1 is 11 dB.mu.V, thus satisfying the predetermined 
quality. 
Moreover, when the transmission output (1c) of the base station 1 is 143 
dB.mu.V, the receiving level of the 0.8 W mobile station 2 is 9 dB.mu.V, 
under the propagation loss of 134 dB. 
The communication level Lth2, as shown in FIG. 9, is 9 dB.mu.V. The 
permission discrimination allows the transmission output (4') of the 
mobile station 2. 
When the transmission output (4') is 142.0 dB.mu.V, the receiving level of 
the base station 1 is 8 dB.mu.V, thus satisfying the predetermined 
quality. 
When the transmission output (1d) of the base station 1 is 143 dB.mu.V, the 
receiving level of the 0.3 W mobile station 2 is 13.3 dB.mu.V, under the 
propagation loss of 129.7 dB. 
The communication level Lth2, as shown in FIG. 9, is 13.3 dB.mu.V. The 
permission discrimination allows the transmission output (5') of the 
mobile station 2. 
When the transmission output (5') is 137.7 dB.mu.V, the receiving level of 
the base station 1 is 8 dB.mu.V, thus satisfying the predetermined 
quality. 
As described above, the communication level KL corresponding to each output 
classification of the mobile station 2 can be set, thus providing a 
predetermined communication quality. 
Next, let us consider the base station 1 with 3 W output, compared with the 
general example shown in FIG. 25. The operation is shown in FIG. 23. 
The communication level KL (Lth2) and the communication out level level RL 
(Lth2') have the values listed in FIG. 10, respectively. 
When the transmission output (6a) of the base station 1 is 147.7 dB.mu.V, 
the receiving level of the 3 W mobile station 2 is 8 dB.mu.V, under the 
propagation loss of 139.7 dB. 
The communication level Lth2, as shown in FIG. 10, is 8 dB.mu.V. The 
permission discrimination allows the transmission output (7') of the 
mobile station 2. 
When the transmission output (7') is 147.7 dB.mu.V, the receiving level of 
the base station 1 is 8 dB.mu.V, thus satisfying the predetermined 
quality. 
When the transmission output (6b) of the base station 1 is 147.7 dB.mu.V, 
the receiving level of the 2 W mobile station 2 is 9.7 dB.mu.V, under the 
propagation loss of 138 dB. 
The communication level Lth2, as shown in FIG. 10, is 9.7 dB.mu.V. The 
permission discrimination allows the transmission output (8') of the 
mobile station 2. 
When the transmission output (8') is 146.0 dB.mu.V, the receiving level of 
the base station 1 is 8 dB.mu.V, thus satisfying the predetermined 
quality. 
Moreover, when the transmission output (6c) of the base station 1 is 147.7 
dB.mu.V, the receiving level of the 0.8 W mobile station 2 is 13.7 
dB.mu.V, under the propagation loss of 134 dB. 
The communication level Lth2, as shown in FIG. 10, is 13.7 dB.mu.V. The 
permission discrimination allows the transmission output (10') of the 
mobile station 2. 
When the transmission output (10') is 142.0 dB.mu.V, the receiving level of 
the base station 1 is 8 dB.mu.V, thus satisfying the predetermined 
quality. 
When the transmission output (6d) of the base station 1 is 147.7 dB.mu.V, 
the receiving level of the 0.3 W mobile station 2 is 18 dB.mu.V, under the 
propagation loss of 129.7 dB. 
The communication level Lth2, as shown in FIG. 10, is 18 dB.mu.V. The 
permission discrimination allows the transmission output (9') of the 
mobile station 2. 
When the transmission output (9') is 137.7 dB.mu.V, the receiving level of 
the base station 1 is 8 dB.mu.V, thus satisfying the predetermined 
quality. 
The communication level KL (Lth2) corresponding to each output 
classification of the mobile station 2 is set. A desired communication 
quality can be obtained. 
The further following effects and advantages can be listed below. 
(1) Excellent line quality and communication quality can be obtained in the 
up and down directions without depending on the difference in transmission 
output between the base station 1 and the mobile station 2. This feature 
contributes to greatly-improved services in mobile communication systems 
such as digital automobile telephones. 
(2) Even when the base station 1 is changed due to a channel switching and 
zone shifting, the broadcast information from the base station 1 is 
quickly received after the switching operation. A communication control 
can be performed using a correction value that corrects plural 
communication levels/communication out level levels or uniform 
communication levels in response to the transmission output after a 
switching operation. In communication to any one of base stations 1, good 
quality can be obtained in the up and down directions. 
(3) The communication level corresponding to the transmission output of the 
self station can be easily selected among plural pieces of communication 
level information sent from the base station 1. The communication out 
level level corresponding to the transmission output of the self station 
can be easily selected among plural pieces of communication out level 
level information sent from the base station 1. 
The present embodiment shown in FIG. 5 is constituted like the modified 
example shown in FIG. 6. 
In the base station 1, the reporting unit 3(3B) is constituted as means 
that reports information regarding a pair of communication levels KL, 
information regarding a communication out level level RL (fixed 
communication control information), and plural pieces of correction value 
information H used to correct information regarding the communication 
levels KL and the communication out level level RL, in response to the 
transmission output P2 of the mobile station 2. In the mobile station 2, 
the control unit 5(5B) includes the selection unit 6(6B) that selects a 
correction value HT corresponding to the transmission output P2 of the 
self station 2 among the communication level KL, the communication out 
level level RL, and plural pieces of correction value information H, each 
sent from the base station 1, the correction value calculating unit 8(8B) 
that corrects the communication level KL and the communication out level 
level RL using the correction value HT selected by the selecting unit 
6(6B), and the discriminating unit 7 that discriminates whether the self 
station 2 is in a communication permission or inhibition state with a 
corrected value. 
Hence, plural pieces of correction value information H in the reporting 
unit 3 is transmitted to the correction value reporting unit 12 via the 
receiving unit 4. The correction value calculating unit 8(8B) calculates 
based on the plural pieces of correction value information H. The 
discriminating unit 7 discriminates whether the self station 2 is in a 
communication permission or inhibition state, using the resultant 
correction value. 
The correction value information H is formed, for example, as shown in 
FIGS. 11 and 12. The case where transmission output P1 of the base station 
1 is 1 W will be described with reference to FIG. 11. When the 
transmission output P2 of the mobile station 2 is 3 W, the correction 
value HT is set to 0 dB. 
When the transmission output P2 of the mobile station 2 is 2 W, the 
correction value HT is set to 0 dB. When the transmission output P2 of the 
mobile station 2 is 0.8 W, the correction value HT is set to +1 dB. When 
the transmission output P2 of the mobile station 2 is 0.3 W, the 
correction value HT is set to 5.3 dB. 
The case where the transmission output P1 of the base station 1 is 3 W is 
described by referring to FIG. 11. When the transmission output P2 of the 
mobile station 2 is 3 W, the correction value HT is set to 0 dB. 
When the transmission output P2 of the mobile station 2 is 2 W, the 
correction value HT is set to 1.7 dB. When the transmission output P2 of 
the mobile station 2 is 0.8 W, the correction value HT is set to +5.7 dB. 
When the transmission output P2 of the mobile station 2 is 0.3 W, the 
correction value HT is set to 10 dB. 
The present modified example with such a configuration performs the 
operation according to the flowchart shown in FIG. 15. The operations in 
the steps S1 to S10 are similar to the above-mentioned operations. Hence 
the duplicate explanation will be omitted here. 
When broadcast information has been received in the step S11(B11), the 
correction value calculating unit 8(8B) performs an arithmetic operation. 
Then the correction value HT shown in FIGS. 11 and 12 is added to the 
receiving level L2 detected in the step S10. The calculated result becomes 
the corrected receiving level L3 (step S11(B1)). 
It is judged whether the corrected receiving level L3 exceeds the 
predetermined value Lth3 as a communication level KL (step S12). If yes, a 
communication permission operation is performed (step S13). 
In such a manner, the condition of the communication permission in which 
the receiving level L2 is corrected corresponding to the transmission 
output P2 of the mobile station 2 is judged. 
After the communication permission, as shown in FIG. 18, the judgment is 
repeated using the correction calculation (step S17) and the predetermined 
value Lth3' as a communication out level level RL. 
In other words, it is confirmed every predetermined calculation period in 
the step S18' that the corrected receiving level L3 is maintained more 
than the predetermined communication out level level Lth3'. When the 
condition is satisfied, the communication state is maintained. If the 
condition is not satisfied, the process (display) for regions out of a 
communicable zone is performed via the "NO" route in the step S18' (step 
S15). 
The resultant effects and advantages are listed as follows: 
(1) Good line quality and communication quality are obtained in the up and 
down directions without depending on the difference in transmission output 
between the base station 1 and the mobile station 2. Hence this feature 
contributes to greatly-improved services in mobile communication systems 
such as digital automobile telephones. 
(2) Even when the base station 1 is changed due to a channel switching and 
zone shifting, broadcast information is quickly received from the switched 
base station 1. A communication control can be performed with a correction 
value used to correct plural communication levels/communication out level 
levels, or uniform communication levels, according to the transmission 
output after the switching operation. Hence good quality can be obtained 
in the up and down directions even at communications to any one of the 
base stations 1. 
(3) The communication level corresponding to the transmission output of the 
self station can be easily selected among plural pieces of communication 
level information sent from the base station 1. The communication out 
level level corresponding to the transmission output of the self station 
can be easily selected among plural pieces of communication out level 
level information sent from the base station 1. 
(4) The correction value corresponding to the transmission output of the 
self station is selected among plural pieces of correction value 
information sent from the base station 1. The communication level and 
communication out level level can be easily corrected using the selected 
correction value. 
The present embodiment shown in FIG. 5 can be constituted like the modified 
example shown in FIG. 7. 
In the modified example, the reporting unit 3(3C) in the base station 1 is 
constituted as means that reports information regarding the transmission 
output P1 of the base station 1 itself, in addition to a pair of 
information regarding the communication level KL and information regarding 
communication out level level RL. In the mobile station 2, the control 
unit 5(5C) includes the transmission output difference calculating unit 13 
that calculates the difference .DELTA.P between the transmission output P1 
of the base station 1 and the transmission output P2 of the mobile station 
2 itself according to information regarding the transmission output P1 
sent from the base station 1, the correcting unit 8(8C) that corrects the 
communication level KL and the communication out level level RL using the 
difference value .DELTA.P as a correction value HT calculated by the 
transmission output difference calculating unit 13, and the discriminating 
means 7 that discriminates whether the self station is in a communication 
permission or inhibition state according to the value corrected by the 
correcting unit 8(8C). 
The transmission output difference calculating unit 13 receives the output 
from the transmission output information reporting unit 14 that reports 
the transmission output information in response to signals received by the 
receiving unit 4. When the receiving level of the self station 2 is more 
than a desired communication level KL and the receiving level corrected 
with the difference .DELTA.P in transmission output between the base 
station 1 and the self station 2 is more than the communication level KL, 
the control unit 5(5C) in the mobile station 2 permits waiting. Where the 
receiving level corrected with the difference .DELTA.P in transmission 
output between the base station 1 and the self station 2 is less than a 
desired communication out level level RL, the control unit 5(5C) in the 
mobile station 2 inhibits waiting. 
The broadcast information shown in FIG. 13 is formed to broadcast 
information regarding the transmission output P1 of the base station 1 
itself. For example, the value, "1" W, or the transmission output P1 of 
the base station 1, exists in the data bit of the base station 
transmission output information. 
The modified example with the above-mentioned configuration operates 
according to the flowchart shown in FIG. 16. The operations in the steps 
S1 to S10 are similar to the above mentioned operations. The duplicate 
explanation will be omitted here. 
When broadcast information has been received in the step S11(C1), the 
correction value calculating unit 8(8C) performs an arithmetic operation 
in the steps S11(C2, C3). 
The difference .DELTA.P between the transmission output P1 of the base 
station 1 and the transmission output P2 of the mobile station 2 is 
calculated in the step S11(C2). Then the correction value HT is calculated 
corresponding to the difference .DELTA.P. 
The correction value HT is subtracted from the receiving level L2 in the 
step S11(C3). Then the calculated result becomes the corrected receiving 
level L3 (=L2-HT). 
It is judged whether the corrected receiving level L3 exceeds the 
predetermined value (communication level) Lth3 (step S12'). If yes, a 
communication permission operation is performed (step S13). 
Thus, the communication permission condition is judged in the receiving 
level L2 corrected corresponding to the transmission output P2 of the 
mobile station 2. 
After the communication permission, as shown in FIG. 19, the transmission 
output difference calculation [step S17(C4)], the correction value 
calculation [step S17(C5)], the correction calculation [step S17(C6)], and 
judgement by the communication out level level Lth3' (step S18') are 
repeated. 
Namely, it is confirmed every predetermined calculation period whether the 
corrected receiving level L3 exceeds a predetermined communication out 
level level Lth3' in the step S18'. If the condition is met, the 
communication permission state is maintained. If not, the process 
(display) for regions out of a communicable zone is performed via the "NO" 
route from the step S18' (step S15). 
The resultant effects and advantages are listed as follows: 
(1) Good line quality and communication line can be provided in the up and 
down directions without depending on the difference in transmission output 
between the base station 1 and the mobile station 2. This feature 
contributes to greatly-improved services in mobile communication systems 
such as digital automobile telephones. 
(2) Even when the base station 1 is changed due to channel switching and 
zone shifting, broadcast information from the base station 1 is quickly 
received after the switching operation. Thus, a communication control is 
made with a correction value used to correct plural communication 
level/communication out level level or uniform communication levels each 
corresponding to the transmission output after the switching operation. 
Hence, good line quality is obtained in the up and down directions at 
communications to any base station 1. 
(3) A communication level corresponding to the transmission output of the 
self station can be easily selected according to plural pieces of 
communication level information sent from the base station 1. A 
communication out level level corresponding to the transmission output of 
the self station can be easily selected according to plural pieces of 
communication out level level information sent from the base station 1. 
(4) A judgement of a communication permission corresponding to the 
transmission output of a self station can be surely performed by 
calculating the difference between the transmission output of the base 
station 1 and the transmission output of the mobile station 2 itself and 
then correcting the communication level and the communication out level 
level, using the resultant value as a correction value. 
(5) Where the receiving level of a self station is more than a desired 
communication level and the receiving level corrected with the difference 
in transmission output between the base station and the self station is 
more than the communication level, waiting is permitted. Where the 
receiving level corrected with the difference in transmission output 
between the base station and the self station is less than the 
communication out level level, waiting is inhibited. Hence the 
communication permission can be surely judged.