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Mobile Phone Patent Abstract
This invention intends to provide a method capable of automatically
selecting one system without a large increase of production cost
in a dual band mobile phone of this invention having both PHS and
GSM functions. First, a common control unit (40) retrieves whether
or not a SIM card (19) is mounted on a card mounting unit (9) by
a SIM card retrieval circuit (41). Next, if the mounting thereof
is detected and storage data is read properly from the SIM card
(19), the GSM function is indicated on a mode lamp (17) so that
communication is carried out by an operation of the GSM mode. On
the other hand, if the mounting of the SIM card (19) cannot be detected
or data cannot be read from the SIM card (19), the PHS mode is set
up by a mode setting circuit (43) instead of the GSM mode. Then,
the PHS mode is indicated on the mode lamp (17) so that communication
is carried out by an operation of the PHS mode. A mode set to be
operating is memorized in a mode memory (13) and if the power is
turned ON, the system starts to operate at this memorized mode.
Mobile Phone Patent Claims
What is claimed is:
1. A band selection method for a dual band mobile phone which includes
both a first system requiring a SIM card and a second system not
requiring the SIM card, said dual band mobile phone including a
mode memory for memorizing a system mode of any one of said two
systems,
said method comprising the steps of:
supplying power to said first system;
detecting whether or not the SIM card is mounted while an operating
mode is regarded as a system mode of said first system;
setting the operating mode to a system mode of the first system
when the SIM card is detected;
supplying power to said second system;
setting the operating mode to a system mode of said second system
if the SIM card is not detected;
supplying power to at least one of (a) said first system, and (b)
said second system;
retrieving a system mode memorized in said mode memory;
retrieving said SIM card when a system mode of said first system
is detected;
setting the operating mode to the system mode of said first system
when the SIM card is detected;
wherein a system mode of any one of said two systems is memorized
in said mode memory at an initial time, and if the power is cut
off after the system mode is started, the operating system mode
is memorized and held.
2. A dual band mobile phone comprising both a first system requiring
a SIM card and a second system not requiring the SIM card,
a card mounting unit for mounting said SIM card,
a power switch for supplying a battery power to a predetermined
circuit,
a mode memory for memorizing any one system mode of said two systems
and a common control unit,
said common control unit including:
a mode detection circuit for detecting a system mode stored in
said mode memory when said power switch is turned on;
a SIM card retrieval circuit for retrieving the SIM card at said
card mounting unit when said mode detection circuit detects a system
mode of said first system; and
a mode setting circuit for setting an operating mode to a system
mode of said first system when the SIM card retrieval circuit detects
the SIM card,
wherein said mode memory memorizes and holds a system mode of any
one of said two systems at an initial time and memorizes and holds
an operating system mode when the power switch is turned off after
the system mode is started.
Mobile Phone Patent Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a band selection method for a
dual-band mobile phone having both the functions of a system requiring
SIM (subscriber identification module) card, for example, GSM (Global
System for Mobile communication) and a system not requiring the
SIM card, for example, PHS (personal handy-phone system) and capable
of automatically selecting and operating any one of the two systems
without inducing an increase in size of the unit structure, and
a mobile phone using the same method.
2. Description of the Related Art
Recently, a dual band mobile phone system capable of using different
communication systems or different frequency bands with a single
mobile phone unit has been developed.
Conventionally, in this kind of band selection method for a dual
band mobile phone and its apparatus, user can automatically or manually
select a system considered optimum depending on a communication
enabled area, busy state of communication lines, communication fee
and the like of each system.
For example, a dual band mobile phone having GSM used world wide
mainly in Europe and PHS used in mainly Japan and Asia has been
developed to a practical use level.
The features of the GSM are use of a frequency band of 900 MHz
and a memory card for storing subscriber information, which is called
SIM card. The SIM card contains user telephone numbers, accounting
information and the like, and if this SIM card is not used, the
GSM terminal cannot be used. Although, for the GSM, its cell area
is wide because of a large output, it is not capable of communicating
underground because no radio network has not been prepared yet and
its communication fee is higher than others.
On the other hand, it is the feature of the PHS that frequency
band of 1.9 GHz is used, its transmission output power is as small
as 10 mW on average, an area which electromagnetic wave can reach
is 100 m in radius from a base station, and therefore, this is suitable
for a small cell type mobile phone system. Therefore, because the
base station can be installed easily at a low cost although the
service area is limited to a small area, it allows communication
underground if a base station is installed, and further communication
fee is cheap.
To solve those problems, a dual band mobile phone suitable for
both the systems has been developed.
Conventionally, in this kind of the dual band mobile phone, user
must select a system for use. For example, the mobile phone is provided
with a mode setting key and by operating this key manually, a system
for use is selected. Further, there is a method in which a system
for use is automatically selected by incorporating a RSSI (Received
Signal Strength Indication) measuring circuit in a common control
unit of a mobile phone. In this case, a field intensity level is
measured according to a control channel signal received from a base
station of each system.
Of the above-described conventional band selection methods for
dual band mobile phone, in case where user manually selects a system
for use, there is a problem that user's selection of system is complicated.
The reason is that the user must select a system considered optimum
depending on the communication enabled area of each system, busy
state of the line, communication fee and the like.
In case of automatically selecting a system for use by measuring
of the RSSI, there is a problem that the size of the mobile phone
is enlarged and production cost is also increased. In any case,
when the GSM requiring the SIM card is selected, if the SIM card
is not loaded, there occurs such a problem that communication cannot
be started while an error message is displayed on a character display.
SUMMARY OF THE INVENTION
The present invention has been made to solve the above problems
and therefore it is an object of the invention to provide a band
selection method for dual band mobile phone which allows automatic
selection of system for use without inducing a large increase of
production cost and a mobile phone using the same method.
To achieve the above object, the present invention provides a band
selection method for dual band mobile phone, having both a first
system requiring a SIM card and a second system not requiring the
same. This band selection method comprises: detecting whether or
not the SIM card is mounted while an operating mode is regarded
as a system mode of the first system when a power switch is turned
on; and setting the operating mode to a system mode of the first
system when the SIM card is detected, while if the SIM card is not
detected, setting the operating mode to a system mode of the second
system. Therefore, user can use the mobile phone without making
consciousness of presence/absence of the SIM card.
In addition to the above, the dual band mobile phone of the present
invention includes a mode memory for memorizing a system mode of
any one of the two systems. The band selection method comprises:
retrieving a system mode memorized in the mode memory when the power
switch is turned on, retrieving the SIM card when a system mode
of the first system is detected, and setting the operating mode
to a system mode of the first system when the SIM card is detected.
Further, either when a system mode of the second system is detected
as a result of retrieval of the mode memory or when it is detected
that the SIM card is not mounted as a result of retrieval of the
SIM card, the system mode of the second system is set up. Therefore,
because the mobile phone may start the functional operation of the
system memorized in the mode memory, the starting operation carried
out when the power is turned on can be simplified.
A dual band mobile phone using the above-mentioned method has both
a first system requiring a SIM card and a second system not requiring
the same. And the dual band mobile phone comprises a card mounting
unit for mounting the SIM card, a power switch for supplying a battery
power to a predetermined circuit and a common control unit. This
common control unit includes an SIM card retrieval circuit and a
mode setting circuit. The SIM card retrieval circuit is provided
for retrieving the SIM card at the card mounting unit while an operating
mode is regarded as a system mode of the first system when the power
switch is turned on. And the mode setting circuit is provided for
setting the operating mode to a system mode of the first system
when the SIM card retrieval circuit detects the SIM card, or setting
the operating mode to a system mode of the second system if the
SIM card is not detected.
The above dual band mobile phone further comprises a mode memory
for memorizing any one system mode of the two systems and a mode
detection circuit included in a common control unit. The mode detection
circuit is provided for detecting a system mode stored in the mode
memory when the power switch is turned on. The above-described SIM
card retrieval circuit retrieves the SIM card at the card mounting
unit when this mode detection circuit detects a system mode of the
first system.
The mode setting circuit of the common control unit may set the
system mode of the second system either when the mode detection
circuit detects the system mode of the second system or when the
SIM card retrieval circuit detects that the SIM card is not mounted.
The aforementioned mode memory is capable of memorizing a system
mode operating when the power switch is turned off. Therefore, in
continuous calls, a new call is capable of selecting a system of
the same condition as the last call, thereby enabling a stabilized
communication. Further, it is also possible to provide with a display
unit for indicating a system mode set by the common control unit
by at least one of characters and a lamp. Therefore, an operating
system on use can be recognized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an embodiment of the present
invention for satisfying the fundamental condition thereof;
FIG. 2 is a flow chart showing an example of main operating procedure
corresponding to FIG. 1;
FIG. 3 is a functional block diagram showing other embodiment of
the present invention than FIG. 1; and
FIG. 4 is a flow chart showing an example of main operating procedure
corresponding to FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Next, the embodiment of the present invention will be described
with reference to the accompanying drawings.
FIG. 1 is a functional block diagram showing an embodiment of the
present invention for satisfying the fundamental condition thereof.
In the dual band mobile phone shown in FIG. 1, the aforementioned
first system is GSM and the second system is PHS.
A dual band mobile phone shown in FIG. 1 comprises a transmitter
unit 1, a receiver unit 2, a transmission/reception circuit 3, a
common control unit 4, a PHS radio unit 5, an antenna 6, a GSM radio
unit 7, a key input unit 8, a card mounting unit 9, a power key
10, a power switch 11, a battery 12, a memory 14, a character display
15, a power lamp 16, and a mode lamp 17.
The transmitter unit 1, receiver unit 2 and transmission/reception
circuit 3 are used in ordinary telephone systems. The common control
unit 4 controls all functions of the mobile phone and specifically
has a SIM card retrieval circuit 21 and a mode setting circuit 22
relating to the present invention. The antenna 6 is connected to
the GSM radio unit 7 as well as the PHS radio unit 5 so that it
is capable of communicating with respective base stations via radio.
The PHS radio unit 5 is available when the PHS is selected by the
common control unit 4. The GSM radio unit 7 is available when the
GSM is selected by the common control unit 4. The key input unit
8 is a key pad or board for inputting a dial number and data.
The card mounting unit 9 is a portion on which the SIM card 19
for use in GSM is to be mounted. If it is so constructed that the
SIM card is inserted, when the card is mounted properly by inserting
the card, card mounting information is transmitted via a predetermined
position. When the SIM card 19 is mounted, data such as subscriber
number and accounting information memorized in the SIM card can
be read by the common control unit 4.
If the power key 10 is turned ON, the power switch 11 is controlled
so as to supply power of the battery 12 to respective portions of
the mobile phone. When power is supplied to the common control unit
4, the power lamp 16 is lit.
The memory 14 stores software to be executed by the common control
unit 4 and data. The character display 15 displays such predetermined
information as input information and operating condition information
via LCD (liquid crystal display) in characters. The power lamp 16
is lit via LED (light emitting diode) when the power switch 11 is
turned ON. The mode lamp 17 is controlled by the common control
unit 4 so as to indicate an operating system via lighting of the
LED. For example, the mode lamp 17 is lit when the PHS is activated
and unlit when the GSM is activated, so that an operating system
can be indicated with a single LED.
An operation under the fundamental condition for system selection
will be described with reference to FIGS. 1 and 2.
If the power key 10 is pressed (step S1), the power switch 11 is
turned ON (step S2) so that power of the battery 12 is supplied
to respective portions thereby starting the operation.
In the common control unit 4, first, whether or not the SIM card
19 is mounted on the card mounting unit 9 is checked by the SIM
card retrieval circuit 21 (step S11).
As a result of this retrieval, if it is detected that the SIM card
19 is mounted (YES in step S12), the common control unit 4 judges
normality of storage data in the SIM card 19 by reading thereof
(step S13).
If the procedure of this step S13 is "normal" so that
the storage data can be read normally, the common control unit 4
sets the GSM mode by the mode setting circuit 22. And the common
control unit 4 keeps the mode lamp 17 unlit to indicate GSM mode
ON and further the GSM mode is indicated in characters on the character
display 15 (step S14).
Next, the common control unit 4 communicates through the GSM radio
unit 7 by the operation of the GSM mode (step S15). If communication
ends and the power key 10 is turned OFF (step S16), the procedure
is terminated.
On the other hand, if the step S12 is "NO" or the step
S13 is "ABNORMAL", the common control unit 4 turns ON
the mode lamp 17 by the mode setting circuit 22 so as to indicate
PHS mode and further the PHS mode is indicated in characters on
the character display 15 (step S21).
If the above step S12 is "NO" the "PHS mode"
is indicated in characters on the character display 15. However,
if the above step S13 is "ABNORMAL", the "PHS mode"
and "SIM card abnormal" are indicated in characters on
the character display 15.
Next, the common control unit 4 communicates through the PHS radio
unit 5 by an operation of the PHS mode (step S22). If the communication
is terminated, the processing proceeds to step S16, in which the
power key 10 is turned OFF so as to terminate the procedure.
Other embodiments of the present invention will be described with
reference to FIGS. 3, 4. In FIG. 3, the same reference numerals
are attached to the same components as FIG. 1 and a description
thereof is omitted.
FIG. 3 is different from FIG. 1 in that the mode memory 13 is added
and a mode detection circuit 42 is added to a common control unit
40. Therefore, although the SIM card retrieval circuit 41 of the
common control unit 40 is the same as conventional, main functions
are the same in the memory 44 and the mode setting circuit 43 of
the common control unit 40, however, details thereof are different
as described below.
That is, first, if the power key 10 is pressed (step S1) and the
power switch 11 is turned ON (step S2), power of the battery 12
is supplied to respective portions of the mobile phone so that operation
thereof is started.
Next, as shown in FIG. 4, if power is supplied, the power lamp
16 is turned ON and the common control unit 40 retrieves storage
mode of the mode memory 13 by the mode detection circuit 42 (step
S31).
A mode of a system activated last is memorized in the mode memory
13 and in the initial state, the PHS is set up. In the common control
unit 40, if the PHS mode is detected (YES at step S32) as a result
of detecting the mode memory 13 by the mode detection circuit 42,
the PHS mode is overwritten on the mode memory 13 immediately by
the mode setting circuit 43 and the mode lamp 17 is turned ON so
as to indicate the PHS mode. Further, the PHS mode is indicated
in characters on the character display 15 (step S33).
Next, the common control unit 40 communicates through the PHS radio
unit 5 by an operation of the PHS mode (step S34) and when the communication
is terminated so that the power key 10 is turned OFF (step S35),
the PHS mode is held as an operation mode memorized at step S33
(step S36) and then the procedure is terminated.
If the above step S32 is "NO" and the GSM mode, not the
PHS mode is selected, the common control unit 40 detects whether
or not the SIM card 19 is mounted on the card mounting unit 9 by
the SIM card retrieval circuit 41 (step S11).
If as a result of this detection, as described with reference to
the above FIG. 2, it is detected that the SIM card 19 is mounted
(YES at step S12). And the common control unit 40 is capable of
reading storage data properly from the SIM card 19 (NORMAL at step
S13). The GSM mode is overwritten on the mode memory 13 by the mode
setting circuit to update the storage. And then the mode lamp 17
is kept unlit so as to indicate the GSM mode and further, the GSM
mode is indicated in characters on the character display 15 (step
S14).
The common control unit 40 communicates through the GSM radio unit
7 by an operation of the GSM mode (step S15). If the communication
is terminated, the processing returns to step S35, in which the
power key 10 is turned OFF. At step S36, the GSM mode which is an
operating mode memorized at step S14 is held and the processing
is terminated.
On the other hand, if the above step S12 is "NO" and
it cannot be detected that the SIM card is mounted, or if the step
S13 is "abnormal" and data cannot be read properly from
the SIM card 19, the common control unit 40 proceeds to the step
S33. In the step, the mode setting circuit 43 overwrites the PHS
mode on the mode memory 13 instead of the GSM mode to update the
storage and the mode lamp 17 is turned ON to indicate the PHS mode.
Further, the PHS mode is indicated in characters on the character
display 15 also. If data cannot be read properly in the above step
S13, abnormality of the SIM card 19 can be further displayed in
characters on the character display 15.
In the above case, the SIM card retrieval circuit of the common
control unit detects a normal mounting of the card by receiving
an electric signal from the card mounting unit. However, it is permissible
to upon retrieval on the SIM card, proceed to a step for reading
storage data of the SIM card immediately and determine that no SIM
card is mounted if no storage data can be read. In this case, it
cannot be discriminated which the reason why the reading of the
storage data is disabled is due to no mounting of the SIM card,
storage data missing in the SIM card or insertion of other card,
and therefore no detailed indication is enabled.
Although in the above description, it has been stated that the
operating mode is indicated with both the lamp and characters, at
least if the mode change-over key is not provided, it is permissible
to indicate with any one or not to indicate anything.
Although in the above description, the functional blocks and operating
procedure have been stated with Figures, allocation of the functions
or change of the operating procedure is free as long as the above
functions are satisfied, and the above statement does not limit
the present invention.
By combining the above described structure with a conventional
structure and adding only the SIM card retrieval function of the
common control unit, an easy-to-use dual band mobile phone can be
obtained without inducing an increase of its size.
According to the present invention, as described above, there is
an effect that the dual band mobile phone, having a system requiring
the SIM card and a system not requiring the SIM card, can be used
without making consciousness of whether or not the SIM card is mounted.
The reason is that upon use, the mobile phone detects whether or
not the SIM card is mounted and depending on whether or not the
SIM card is mounted, the GSM mode or PHS mode can be automatically
set up.
Further, according to the present invention, a mode memory for
storing a system mode of any one of two systems is provided and
the system is actuated by a system mode memorized in the mode memory
when the power switch is turned ON. Therefore, a starting operation
when the power is turned ON can be simplified.
Further, because the aforementioned mode memory holds in store
a system mode being actuated when the power switch is turned OFF,
in continuous calls, a new call is capable of preferentially selecting
a system of the same condition as the last call, thereby enabling
a stabilized communication. Further, by providing with a display
unit for indicating an operating system mode by at least one of
characters and a lamp, the operating system can be recognized. |