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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a telephone. More specifically,
the present invention is directed to a telephone capable of being
increasing the call connection efficiency in the telephone system.
2. Description of the Prior Art
Very recently, rapid digital technology has been realized in the mobile
communication system, so that the analog type mobile communication system
could be replaced by the digital type mobile communication system.
Normally, the control signal should be transmitted and received between
the radio base station connected to the communication line network and the
portable telephone in the mobile communication system. When the digital
signal is utilized as this control signal, it is possible to establish
such a basic system capable of realizing radio signal transmissions at a
high efficiency and also high communication quality. Moreover, utilization
of the digital technique in the mobile communication system could make
compact radio base stations as well as compact portable telephone,
resulting in easy portability of the portable telephone.
Under such circumstances, a substantial amount of digital portable
telephones have been rapidly marketed. This is because various problems of
the conventional analog type portable telephone system could be
effectively solved. That is, since the usable frequency allocation in the
analog type portable telephone system is restricted, it is not so easy to
increase the total number of telephone subscribers. Furthermore, the
privacy of telephone conversations could not be satisfactorily protected.
However, these problems belonging to the analog type portable telephone
system can be successfully solved by the digital type portable telephone
system.
On the other hand, a so-called "second generation cordless telephone
system" in which the digital technology is comprehensively utilized is
practically studied. A radio telephone utilized in this second generation
cordless telephone system has such a feature that this radio telephone may
be used as the original portable telephone and also a cordless telephone
of a mother telephone.
In other words, the radio telephone used in the second generation cordless
telephone system separately establishes one communication channel with the
public radio base station connected to the communication line network, and
another communication channel with the private (customer) radio base
station corresponding to the own mother telephone. Also, the communication
areas capable of establishing the independent communication channels
between the respective base stations and the own telephone. However, there
is a limitation in using the cordless (radio) telephone belonging to the
private radio base station, although any radio telephones can be freely
used with the public radio base station. When the dialed (called) radio
telephone is used as the cordless telephone, the telephone calling person
needs to dial the customer telephone number (private telephone number) of
the radio telephone. When the called radio telephone is used as the
portable telephone, the telephone calling person needs to dial the
telephone number (public telephone number) of the radio telephone itself.
In this second generation cordless telephone system, the communication
areas of the radio base stations are limited to the small zones referred
to as "microcells". In these microcells, the same frequencies are
repeatedly utilized to make up a large number of communication channels.
In other words, the limited frequency resource can be effectively
utilized. Furthermore, since the dimension of the communication zone
(cell) is restricted to a small value, the transmission power of the radio
telephone may be made low, so that a compact radio telephone with low
power consumption can be made available. That is, the physical size of the
batteries mounted on this radio telephone becomes small, and a long
operation time of the radio telephone can be achieved.
However, the above-described second generation cordless telephone system
has the following drawbacks. That is, while an available range of
communication for one radio base station is limited to several hundred
meters (radial direction), the same frequencies are usable in the
different communication zones at the same time so as to effectively
allocate all the usable radio frequencies. To this end, the radio base
stations must be installed at 100 meter intervals. Thus there is such a
problem that the radio telephone should be continuously located near the
relevant radio station, e.g., shorter than 100 meters. When the opposite
(called) radio telephone is used as the cordless telephone of the mother
telephone, and even when the telephone calling person dials the public
telephone number of this called radio telephone, he cannot access this
called radio telephone. On the other hand, when the opposite radio
telephone is utilized as the portable telephone, there is another problem
that even if the telephone calling person dials the private telephone
number of this called radio telephone, then he cannot access this called
radio telephone.
There are some possibilities in the second generation cordless telephone
system that the radio telephone cannot establish the communication in case
that the radio telephone is located outside the available range of
communication covered by the public radio base station, is not set to the
telephone waiting condition, or the relevant communication channel is
fully occupied by other radio telephones.
One solution has been proposed as the radio telephone equipped with the
paging function. That is, the radio telephone is combined with a pager
with low power consumption operable in the paging system which can cover a
wider communication range than that of the second generation cordless
telephone system. That is, such a wide communication range can be
established by utilizing the radio telephone with the paging function in
such a manner that the pager communication can be made with another radio
telephone equipped with the paging function located outside the available
range of communication in the second generation cordless telephone system.
However, when no telephone line is connected in case that the user issues
the telephone calling to the opposite (called) radio telephone with the
paging function by utilizing the second generation cordless telephone
system, he should make another telephone calling with using the paging
system. Under such circumstances, there is a drawback that a desired
telephone number is selected from a plurality of stored telephone numbers,
or the relevant telephone number should be inputted so as to make a
telephone call.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a telephone capable of
simply dialing a telephone number related to a desired telephone number
when no telephone line is connected in case that this desired telephone
number is dialed.
To achieve the object, a telephone, according to one aspect of the present
invention, comprises memory means for storing both a telephone number of a
called person and a telephone number related to the first-mentioned
telephone number; and instruction means for instructing to make a
telephone call to said related telephone number stored in said memory
means when no telephone line is connected in case that a telephone call is
made to said telephone number of the called person.
In the telephone with the above-described arrangement, when no telephone
line is connected in case that the desired telephone number is dialed,
another telephone number related to this desired telephone number can be
simply dialed. As a result, the call connection efficiency can be
increased.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference is made of
the detailed description to be read in conjunction with the accompanying
drawings, in which:
FIG. 1 schematically represents the overall system arrangement of the
second generation cordless telephone system in which a telephone according
to the present invention is utilized;
FIG. 2 is a schematic storage region of a memory employed in the control
center of FIG. 1;
FIG. 3 is a perspective view for showing a mother telephone installed in a
home;
FIG. 4 is a perspective views for indicating a radio telephone utilized as
a portable telephone, or a cordless telephone belonging to the mother
telephone within the telephone system of FIG. 1;
FIG. 5 is a schematic block diagram for indicating a circuit arrangement of
the radio telephone shown in FIG. 4;
FIG. 6 schematically represents a memory map about names, telephone
numbers, and other telephone numbers related thereto, which are registered
in the RAM of FIG. 5;
FIG. 7 schematically illustrates a flow of a communication control
procedure executed among the calling radio telephone, the communication
line network, and the called person when the telephone call is made from
the radio telephone shown in FIG. 1;
FIG. 8 is a flow chart for explaining a dialing procedure executed under
control of the control unit shown in FIG. 5;
FIG. 9 indicates a display example of the public telephone number
registered in the RAM of FIG. 5;
FIG. 10 represents a display example of the private telephone number
registered in the RAM of FIG. 5;
FIG. 11 schematically shows another memory map about names, telephone
numbers, and other telephone numbers related thereto, registered in the
RAM of FIG. 5;
FIG. 12 is a flow chart for explaining another dialing procedure executed
under control of the control unit shown in FIG. 5;
FIG. 13 is another display example of the private telephone number
registered in the RAM of FIG. 5;
FIG. 14 is a display example of the telephone number in the voice mail
center, registered in the RAM of FIG. 5;
FIG. 15 schematically shows another overall system arrangement constructed
of a paging system and a second generation cordless telephone system;
FIG. 16 is a schematic block diagram for representing a radio telephone
equipped with a paging function utilized as a pager and a radio telephone
of FIG. 15;
FIG. 17 schematically shows another memory map about names, telephone
numbers, and other telephone numbers related thereto registered in the RAM
of FIG. 16;
FIG. 18 schematically illustrates a flow of a communication control
procedure among the calling radio telephone, the communication line
network, and the called radio telephone equipped with the paging function
when the telephone call is made from the radio telephone of FIG. 15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Overall Telephone Communication System
Referring now to FIG. 1 to FIG. 8, a telephone according to a first
preferred embodiment of the present invention will be described in detail.
In FIG. 1, there is schematically shown an overall telephone communication
system of the second generation cordless telephone system to which the
radio telephone according to the first preferred embodiment is applied. As
represented in FIG. 1, this cordless telephone system is arranged by a
communication line network 1, a telephone 2 connectable via a station line
to this communication line network 1, a customer mother telephone 3, and
public radio base stations 4 and 5 for public use. To the customer mother
telephone 3, the radio telephone 6 utilized as the cordless telephone in
the second generation cordless telephone system is accessed. To the public
radio base stations 4 and 5 for public use, the radio telephones 7 and 8
utilized as the portable radio in the second generation cordless telephone
system are accessed. Otherwise, another radio telephone 9 is accessed to
the public radio base stations 4 and 5 when this radio telephone enters
into the radio communication zones or areas of these public radio base
stations 4 and 5. Also, the radio telephone 6 is brought out from the home
so as to be used as the portable telephone in the second generation
cordless telephone system, and may be used as the portable telephone when
this radio telephone 6 is located within the radio communication zones of
the public radio stations 4 and 5.
In FIG. 1, reference numeral 10 indicates a control center in the second
generation cordless telephone system. This control center 10 employs a
memory capable of storing a plurality of public telephone numbers
(telephone numbers used in public line) for plural radio telephones, a
plurality of ID codes, and a plurality of present area numbers for
registering where the radio telephones are presently located (see FIG. 2).
Upon receipt of a telephone number of a radio telephone 7, 8, or 9 in
question from the public radio base stations 4 or 5 via the communication
network 1, the control center 10 retrieves this telephone number from the
above-described memory. Then, when this retrieved telephone number is
registered in this memory, the control center 10 transmits a calling
signal to such a radio telephone, the position of which has been
registered based on the present area number stored in correspondence to
this telephone number. Also, reference numeral 11 indicates a voice mail
center. This voice mail center is utilized as follows. In case that a
telephone calling person could not succeed in the line connection with
another radio telephone to be called, he may record his message in the
message mail box of the vice mail center, and thereafter a called person
may access this message mail box to fetch the above-described message.
It should be noted that this communication line network 1 may be realized
by employing PSTN (Public Switched Telephone Network) and ISDN (Integrated
Service Digital Network).
Outer Appearances of Portable Telephone/Customer Mother Telephone
FIG. 3 shows an outer appearance of the customer mother telephone 3 used in
the telephone system of FIG. 1. As illustrated in FIG. 3, the customer
mother telephone 3 is arranged by an handset 12 having therein a
microphone for inputting voice and a speaker for reproducing voice; a key
input unit 13 equipped with a number entry key used to enter telephone
numbers and an operation key used to operate a telephone answering machine
14; and the telephone answering machine 14 for recording a voice message
received during the automatic answering mode. The customer mother
telephone 3 is further comprised of a liquid crystal display (LCD) unit 15
for displaying a key entered content made by the key input unit 13, a
message recorded in the telephone answering machine 14, and various sorts
of function guide; and an antenna 16 for transmitting/receiving a radio
signal to/from the radio telephone 6.
FIG. 4 schematically shows an outer appearance of the above-described radio
telephone 6, 7, 8, or 9 employed in the telephone system of FIG. 1. As
shown in FIG. 4, the radio telephone is provided with an antenna 21 for
transmitting/receiving the radio signal among the customer mother
telephone 3 and the public radio base stations 4, 5; and a LCD (liquid
crystal display) unit 22 for displaying a key entered content made by the
key input unit 23, and various sorts of function guidance. This radio
telephone is further provided with such a key input unit 23 comprised of a
dialing key 23a, a telephone ending key 23b, a mode key 23c, a selection
key 23d, and a register key 23e, and also a numeral entry key 23f; a
speaker 24 for reproducing voice; a microphone 25 for inputting a voice
message; and a speaker 26 for ringing purposes.
Circuit Arrangement of Radio Telephone
In FIG. 5, there is shown a circuit block diagram of the radio telephone
shown in FIG. 4. This radio telephone includes a switch (SW) 27, a
receiving unit 28, a transmitting unit 29, a synthesizer 30, a digital
modulating/demodulating unit 31, a TDMA processing unit 32, a speech codec
unit 33, a speech (voice) converting unit 34, a control unit 35, a ROM 36
and a RAM 37 in addition to the above-described antenna 21, LCD unit 22,
key input unit 23, speaker 24, microphone 25 and ringer speaker 26, as
shown in FIG. 4.
The antenna 21 is operated as follows. That is, this antenna 21 is used to
transmit/receive a calling signal and a voice signal, which are in a
preselected frequency band, to/from either the customer mother machine 3,
or the public radio base stations 4 and 5. Furthermore, the signal
received by this antenna 21 via the switch 27 is supplied to the signal
receiving unit 28, whereas the signal inputted from the transmitting unit
29 via the switch 27 is transmitted by this antenna 21.
The switch 27 switches the connections between the receiving unit 28 and
the transmitting unit 29 with respect to the antenna 21 under switching
control by the control unit 35. Normally, the antenna 21 is connected via
the switch 27 to the receiving unit 28, whereas the antenna 21 is
connected via the switch 27 to the transmitting unit 29 during the
transmitting operation.
When the receiving unit 28.receives the signal at the reception frequency
band set by the synthesizer 30 via the switch 27 from the antenna 21, this
reception signal is amplified at a preselected amplification and then the
amplified signal is outputted to the digital modulating/demodulating unit
31. Upon receipt of the signal from the digital modulating/demodulating
unit 31, the transmitting unit 29 transmits the signal at the
predetermined frequency band set by the synthesizer 30 via the switch 27
from the antenna 21.
In synthesizer 30 sets such a frequency band to the receiving unit 28 and
the transmitting unit 29 when the oscillation frequency band is instructed
by the control unit 35.
The digital modulating/demodulating unit 31 digitally demodulates the
received signal which has been digitally modulated and entered from the
receiving unit 28 to output the demodulated signal to the TDMA processing
unit 32. Also, the digital modulating/demodulating unit 31 digitally
modulates the transmitted signal entered from the TDMA processing unit 32
to output the modulated signal to the transmitting unit 29.
The TDMA (Time Division Multiple Access) processing unit 32 owns the
following functions. That is, the transmission/reception voice signals are
supplied/received between the digital modulating/demodulating unit 31 and
the speech codec unit 33 via this TDMA processing unit 32, and a
communication control signal is supplied/received between the control unit
35 and this TDMA processing unit 32. In the TDMA processing unit 32
extracts the real data of the digital data received at a predetermined
time slot, and also the header unit entered from the control unit 35 is
added to the digital data (voice data) formed within the radio telephone
and thereafter the resultant digital data is converted into a
predetermined data format. Then the format-converted data is inserted into
a predetermined time slot, which will be outputted to the digital
modulating/demodulating unit 31.
The speech codec unit 33 expands the digital voice data which has been
compressed by way of the ADPCM method and is entered from the TDMA
processing unit 32, to output the digital expanded voice data to the
speech converting unit 34, and also compresses the digital voice data
entered from the speech converting 34 by way of the ADPCM method to output
the digital compressed voice data to the TDMA processing unit 32.
The speech converting unit 34 is provided with an A/D converter and a D/A
converter and so on. This speech converting unit 34 converts the digital
voice data entered from the speech codec unit 33 into an analog voice
signal which will then be supplied to the speaker 24, and further converts
the analog voice signal entered from the microphone 25 into the digital
voice data which will then be supplied to the speech codec unit 33.
The control unit 35 is constructed of a CPU (central processing unit) and
the like. This control unit 35 executes the communication control process
in accordance with the communication control process program stored in the
ROM 36, so that the operations of the above-described various circuit
units are controlled, and such an announcement made by the ringer speaker
26 that the telephone call is made is controlled, and also the display of
the telephone number entered from the key input unit 23 on the LCD unit 22
is controlled. In addition, the control unit 35 executes the dialing
process in accordance with a dialing process program (will be discussed
later) previously stored in the ROM 36. During the execution of this
dialing process, when the line connection with the opposite telephone
cannot be established, the control unit 35 performs such a dialing process
that the dialing signal is issued to the opposite telephone having the
telephone number previously registered in the RAM 37. Then, the control
unit 35 causes this telephone number in this dialing process to be
displayed on the LCD unit 22.
The ROM (read-only memory) 36 previously stores therein the communication
control process program and the dialing process program and the like,
which are executed by the control unit 35.
The RAM (random access memory) 37 has a data area used to temporarily store
the various data produced when the control unit 35 performs the
communication control process and the dialing process. Furthermore, as
illustrated in FIG. 6, another memory area is provided in the RAM 37, in
which a plurality of names, telephone numbers, and other telephone numbers
related thereto are stored. As to the first-mentioned telephone numbers,
the telephone numbers for public use of the radio telephone (public
telephone numbers) are stored, whereas as to the second-mentioned related
telephone numbers, the telephone numbers for customer use of the radio
telephones (private telephone numbers) and also the telephone numbers of
the voice mail center 11 corresponding to the communication service center
are stored.
The LCD unit 22 displays various sorts of display data entered from the
control unit 35. The ringer speaker 26 produces the ringer sound in
response to the ringer signal outputted when the calling signal is
received during the communication control process executed by the control
unit 35.
Overall Operation of First Telephone System
Before describing the overall operation of the telephone system according
to the first preferred embodiment shown in FIG. 1, the telephone number
registering methods will now be described.
First, both of the opposite (called) telephone numbers and the telephone
numbers related thereto are previously registered in the radio telephones
6, 7, 8, 9. There are the below-mentioned methods for registering the
telephone numbers.
1). When the register mode is set by operating the mode key 23c provided in
the key input unit 23 of the radio telephone, the register image is
displayed on the LCD unit 22. Then, the numeral entry keys 23f are
manipulated to enter the customer telephone number, the public-use
telephone number, and the telephone number of the voice mail center.
2). When the register key 23e provided in the key input unit 23 of the
radio telephone is depressed during the telephone conversation, both of
the public-use (public line) telephone number and the private-use
(customer) telephone number, which have been previously registered into
either the opposite radio telephone, or the opposite mother telephone, are
fetched so as to be automatically registered. It should be noted that as
to the second register method 2), since the telephone numbers previously
registered into the opposite telephone are freely registered, such a
register prohibit mode and the like must be employed in the radio
telephone in order that the own telephone number is not registered into
the opposite telephone without any permission.
As is apparent from the foregoing descriptions, the telephone number
registering method may be achieved by employing other registering methods
than the above-described registering method (1) and (2).
Communication Control Procedure
Referring now to a signal flow operation shown in FIG. 7, the communication
control procedure will be described which is executed among the calling
radio telephone 8, the network (public radio base stations 4, 5,
communication line network 1, and control center 10), and the opposite
radio telephone 9 and also the mother telephone 3. The radio telephone 8
sends the calling signal to the radio telephone 9 utilized as the cordless
telephone of the customer mother telephone 3.
In FIG. 7, when the telephone number (public telephone number) of the
opposite radio telephone 9 is selected by operating the selection key 23d
mounted on the key input unit 23 of the calling radio telephone 8 to be
displayed, and thereafter the dialing key 23a is manipulated, the dialing
signal in the radio signal is transmitted from the transmitting unit 29 of
the radio telephone 8 via the antenna 21 toward the public radio base
station 5. This dialing signal is sent from the public radio base station
5 via the station line to the communication line network 1. When this
dialing signal is received so that the telephone number of the opposite
radio telephone 9 is transferred from the communication line network 1 via
the telephone line to the control center 10, the control center 10
retrieves from the memory shown in FIG. 2 whether or not the opposite
telephone 9 has been registered. When this opposite radio telephone is
registered, a calling signal is transmitted via the communication line
network 1 to the opposite radio telephone 9.
At this time, the calling signal is outputted for a predetermined time
period "t" (see FIG. 7), during which such an RBT (ring back tone) signal
indicating that the telephone calling is made now is transmitted from the
communication line network 1 to the calling radio telephone 8. When no
response signal is returned from the opposite radio telephone 9 during
this time period "t", such an announce signal that no answer is made from
the called person is transmitted via the communication line network 1 to
the radio telephone 8. It should be understood that when the radio
telephone 9 is not registered, the control center 10 immediately transmits
such an announce signal that this radio telephone 9 is to registered to
the radio telephone 8.
When the user of the radio telephone 8 who has heard such an announce
signal that no answer is received from the called person executes the
telephone ending process by operating the telephone ending key 23b, the
customer telephone number (the private telephone number) related to the
public telephone number of the opposite radio telephone 9 previously
registered into the RAM 37 is displayed on the LCD unit 22. Thereafter,
the dialing process is executed by operating the dialing key 23a, so that
the dialing signal in the radio signal is transmitted from the
transmitting unit 29 employed in the radio telephone 8 via the antenna 21
to the public radio base station 5. Then, this dialing signal is
transmitted from the public radio base station 5 via the telephone line to
the communication line network 1. As a result, the dialing signal is sent
to the mother telephone 3 of the opposite radio telephone 9, and also such
an RBT signal that the telephone calling is made now is transmitted to the
calling radio telephone 8.
When the response signal issued from the mother telephone 3 of the opposite
radio telephone 9 is returned to the communication line network 1 in
response to the transmission of this calling signal, the response signal
is transmitted from the communication line network 1 to the calling radio
telephone 8. As a result, the telephone line is connected so that the
telephone communication is commenced between the calling radio telephone 8
and the mother telephone 3 of the opposite radio telephone 9 (or radio
telephone 6). At this time, in case that the opposite radio telephone 9 is
located within the communication area of the customer mother telephone 3
and is utilized as the cordless telephone of this customer mother
telephone 3, the telephone conversation is commenced between the calling
radio telephone 8 and the called (opposite) radio telephone 9.
Dialing Process Operation
Referring now to a flow chart shown in FIG. 8, a description will be made
of the dialing process operation executed in the control unit 35 within
the radio telephone 8.
In FIG. 8, when the mode key 23c employed in the key input unit 23 of the
radio telephone 8 is manipulated to set the memory dial mode the public
telephone number of the opposite (called) radio telephone 9 is selected
from the telephone number stored in the RAM 37 by operating the selection
key 23d, the selected telephone number is displayed on the LCD unit 22
(see FIG. 9) at a first step S1. At the next step S2, a check is done as
to whether or not the dialing key 23a is manipulated. When the dialing key
23a is not operated, another check is done as to whether or not the
telephone ending key 23b is manipulated at a step S3. That is, when the
telephone ending key 23b is not manipulated, the dialing process operation
is returned to the step S2. Subsequently, this process operation is
repeatively performed until either the dialing key 23a or the telephone
ending key 23b is operated.
To the contrary, when the dialing key 23a is manipulated, the dialing
output process to the telephone number selected and displayed at the step
S4 is carried out. Subsequently, another judgement as to whether or not
the telephone line is connected to the opposite (called) radio telephone 9
may be done by checking whether or not the above-described response signal
transmitted from the communication line network 1 at a step S5. Also,
another check is made as to whether or not the telephone ending key 23b is
operated at a step S6. When neither the telephone line is connected, nor
the telephone ending key 23b is operated, the process operation is
returned to the previous step S5. Subsequently, the process operations
defined at the step S5 and the step S6 are repeated until either the
telephone line is connected, or the telephone ending key 23b is operated.
When the telephone ending key 23b is manipulated at the step S6, the
customer telephone number of the opposite radio telephone 9 is displayed
on the LCD unit 22 as shown in FIG. 10, and then the process operation is
returned to the process operation defined at the step S2. As a
consequence, the process operations defined at the step S2 and the step S3
are repeatively performed. When the dialing key 23a is manipulated, the
dialing output process is carried out at a step S4, whereby the customer
mother telephone 3 is called.
On the other hand, when the telephone line is connected between the calling
radio telephone 8 and the opposite radio telephone 9 called at the step
S5, the operation is brought into the telephone conversation condition at
a step S8. Next, a check is done as to whether or not the telephone
conversation is ended by checking whether or not the telephone ending key
23b is manipulated at a step S9. When it is so judged that the telephone
conversation is ended, the waiting mode is set to complete this dialing
process at a step S10.
When this dialing process is wanted to be ended, the telephone ending key
23b is manipulated at the previous step S3 to set the waiting mode so that
this dialing process is accomplished.
As previously described, in accordance with the first preferred embodiment,
either the private (customer) telephone number related to the public
telephone number, or the telephone number of the voice mail center is
previously stored within the RAM 37 employed in the radio telephone 8.
When no response is issued from the called radio telephone, the related
telephone number, namely either the customer telephone number, or the
telephone number of the voice mail center is automatically displayed on
the LCD unit 22 and then the dialing operation can be made by operating
only the dialing key. As a result, the message can be recorded by
utilizing the automatic answering function provided in the mother
telephone. When the opposite radio telephone is set within the home, the
message can be sent via the mother telephone.
When the dialing operation is made to the voice mail center 11, the message
may be inputted by designating the message storage unit which has been
allocated to the calling person.
Accordingly, since the call connecting efficiency when the desired radio
telephone is dialed in the second generation cordless telephone system can
be increased, the utilization efficiency of this second generation
cordless telephone system can be improved.
The first preferred embodiment has been described with respect to such a
case that the telephone number (public telephone number) registered in the
telephone number column of the memory map shown in FIG. 6 is selectively
displayed, and when this displayed telephone number is dialed and then no
telephone line is connected, the related telephone number (customer
telephone number) previously registered in the memory map is dialed.
Alternatively, when the telephone number (customer telephone number)
registered into the relevant telephone number column of the memory map
shown in FIG. 6 is selectively displayed and when the displayed telephone
number is dialed, no telephone line is connected, the corresponding
telephone number (public telephone number) registered in the telephone
number column may be dialed.
Second Radio Telephone Used in Telephone System
Referring now to FIG. 11 to FIG. 14, a radio telephone according to a
second preferred embodiment utilized in the second generation cordless
telephone system will be described.
FIG. 11 schematically shows a memory map for storing a plurality of names,
a plurality of telephone numbers, and a plurality of telephone numbers
(first related telephone number, second related telephone number) related
to the first-mentioned telephone numbers. This memory map is provided
within the RAM 37 of the radio telephone 6, 7, 8, or 9. As the telephone
number, the public telephone number is stored. As the first related
telephone number, the p | | |
