JP2000295179A - Communication terminal - Google Patents

Abstract

(57) Abstract: A communication terminal having an infrared port sets an optimum infrared transmission intensity in infrared communication with an external terminal to increase a battery operating time. Prior to communication of voice or data with an external terminal, a CPU (40) controls a level control unit (46c) by controlling a level control unit (46c) for each partner terminal discovery procedure that is repeated every predetermined time until a partner terminal on an infrared interface is discovered. The infrared transmission intensity is increased, and the infrared transmission intensity of a frame after the partner terminal discovery procedure is fixed to a predetermined value based on the infrared transmission intensity at the time when the partner terminal is found.
Thereby, the infrared transmission intensity for performing infrared communication with the external terminal can be optimized and fixed, so that the operation time of the mobile communication terminal can be extended by extending the life of the battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal having an infrared port, which can perform outgoing / incoming call control and voice or data communication from an external terminal via an infrared port.

[0002]

2. Description of the Related Art In recent years, PDCs (Personal Digital Cellu
lar) mobile phone and PHS (personal handyp)
Hone system) type mobile phones are rapidly spreading. By the way, these mobile communication terminals include FIG.
As shown in FIG. 1, an external port is provided at a lower portion of the main body of the mobile communication terminal 20 or the like, and includes a call control control serial signal line corresponding to RS-232C, a communication CH signal line for transferring voice / data over a communication channel, and the like. A wired external interface connector 21 is provided to enable voice and data communication from an external terminal 23 such as a personal computer.

For example, if a vehicle-mounted device 22 having a built-in external antenna and a booster amplifier is connected via a wired external interface connector 21 of a mobile communication terminal 20, voice communication using the hands-free function of the vehicle-mounted device 22 can be performed. . If the external terminal 23 is connected to the mobile communication terminal 20 via the wired external interface 21, data communication by the external terminal 23 can be performed.

[0004] In particular, data communication in mobile communication is so-called "mobile computing", and its application field is expanding and data communication is being speeded up. Speed is becoming the limit. In the case of a wired external interface, it is necessary to carry a connection cable for connecting between the mobile communication terminal 20 and the external terminal 23, which causes inconvenience such as poor usability. Furthermore, since the connection connector of the wired external interface 21 is required to be ultra-small and thin, there is an inconvenience that the connection surface may be damaged due to abrasion of the contact surface due to connection and disconnection of the cable.

[0005] From the viewpoints of improving the communication speed, reducing the cable, and improving the convenience of the user as described above, studies have been made to introduce infrared communication into the interface between the mobile communication terminal 20 and the external terminal 23 and to make it wireless. Is being promoted. Infrared communication is being standardized by IrDA (Infrarse Data Association).
It is considered that infrared rays are introduced into an external interface of the mobile communication terminal 20.

FIG. 12 shows a mobile communication terminal 30 in which infrared communication is introduced into an external interface. FIG.
As shown in FIG.
An infrared transmission / reception window 31 is provided.
By facing each other with the in-vehicle device 32 having the reception window 33 and the external terminal 34 having the infrared transmission / reception window 35, one-to-one communication between the in-vehicle device 32 and the external terminal 35 is possible.
Voice or data transmission can be performed by high-speed infrared communication of 15 Kbps or more.

[0007]

As described above, the infrared interface is already used for a personal computer or a PDA.
Some devices are equipped as standard as an external communication port such as a (personal digital assistant), and it is expected that the standardization of the procedure for sending and receiving calls to and from the mobile communication terminal and the procedure for transferring voice / data will proceed in the future.

By the way, the infrared interface is based on the premise that the distance between the mobile communication terminal 30 and the external terminal 34 is within a predetermined line-of-sight distance. Further, the distance between the two performing infrared communication depends on the transmission power and the radiation width of the two infrared transmission units, the light receiving characteristics of the infrared reception unit, the transmission speed, and the like. Increasing the transmission power or the light receiving sensitivity increases the communication distance, but is not desirable for a portable communication terminal or a data communication terminal that operates on a battery. Therefore, during infrared communication, it is necessary to fix or pay attention so that the installation positions and directions of both terminals do not shift.

[0009] In a battery-powered portable terminal or data communication terminal, there is a demand to save as much power as possible for transmitting infrared rays. However, the transmission intensity of infrared rays affects the reliability of transmission, and the terminal installation position is determined according to the attachment position of the infrared transmission / reception window when performing infrared communication,
Since the distance between the two cannot be specified in advance, a certain level of transmission strength must be ensured. That is, in the conventional communication terminal, the transmission intensity of infrared rays cannot be unconditionally reduced to save power, and a transmission intensity sufficient for performing infrared communication has been determined in advance.

When performing infrared communication, it is considered that communication is started with the infrared transmission / reception windows of both terminals as close as possible so that stable transmission is performed at a predetermined transmission intensity.

Conventionally, the transmission intensity is the same irrespective of the installation distance of both terminals, so that when the installation distance is short, wasteful power is used for infrared communication.

FIG. 13 is a flowchart for explaining a specific processing procedure of a communication partner discovery procedure in a conventional communication terminal. The instruction to start the procedure on the primary side (the terminal that has started the terminal discovery procedure) is issued, for example, by an incoming call from another mobile communication device (Step S).
1). Note that the communication start instruction indicates a case where it is necessary to perform communication with a communication terminal with an infrared interface of an external terminal due to the above-described incoming call or the like.

First, a terminal discovery procedure subroutine on the primary side is executed in response to a communication start instruction (same as the processing shown in FIG. 4 used in the detailed description of the invention) (step S).
2). If the partner terminal is returning an XID response by the terminal discovery procedure subroutine on the primary side (step S3), a flag indicating that an XID frame has been received is set.

If the XID frame can be received and the received XID frame is a response frame of a correct discovery procedure (steps S3 and S4), the procedure proceeds to the next step. As a result of executing the discovery procedure, if no XID frame has been received (step S3) or if the received frame is not a valid response (step S4), a discovery procedure activation timer is started (step S4).
5) The discovery procedure is executed again after the timer times out (step S6).

[0015] The present invention has been made in view of the above-mentioned circumstances, and a communication terminal having an infrared port sets an optimum infrared transmission intensity in infrared communication with an external terminal to increase battery operation time. It is an object of the present invention to provide a communication terminal that can perform the communication.

[0016]

SUMMARY OF THE INVENTION The present invention relates to a communication terminal for communicating with an external terminal via an infrared port, wherein a predetermined command for discovering a partner terminal on the infrared interface prior to communication with the external terminal. A first means for transmitting a frame at a predetermined infrared transmission intensity from the infrared port when executing a partner terminal discovery procedure repeated at predetermined time intervals, and a predetermined command frame transmitted by the first means. Means for receiving a response frame transmitted from an external terminal, and when the response frame has not been received by the second means, in a partner terminal discovery procedure after a predetermined time,
A predetermined command frame is transmitted by increasing the infrared transmission intensity by the first means from the previous transmission, and a response frame transmitted from an external terminal corresponding to the predetermined command frame is received by the second means. In this case, there is provided a third means for fixing the infrared transmission intensity at which the predetermined command frame is transmitted by the first means at this time as the infrared transmission intensity used in the procedure after the partner terminal discovery procedure. .

According to such a configuration, prior to the voice or data communication with the external terminal, the infrared transmission intensity of the frame is determined for each partner terminal discovery procedure which is repeated every predetermined time until a partner terminal on the infrared interface is discovered. , And based on the infrared transmission intensity at the time when the partner terminal can be found, the infrared transmission intensity of frames after the partner terminal discovery procedure is fixed to a predetermined value. Thereby, the infrared transmission intensity for performing infrared communication with the external terminal can be optimized and fixed, so that the operation time of the mobile communication terminal can be extended by extending the life of the battery.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a mobile communication terminal with an infrared port according to the present embodiment. As shown in FIG. 1, a mobile communication terminal to which the present invention is applied has a microcomputer (CPU) 40 as a core and a read-only memory (RO) in which a program for controlling the entire system is stored on a control bus of the CPU 40.
M) and variable values for controlling various processes (S
a read / write memory (RAM) 41 for temporarily storing, for example, lotCT, MaxSlot, etc.), a baseband unit 42 for performing transmission / reception control based on an instruction from the CPU 40 and multiplexing / demultiplexing / speed / signal conversion of voice codes, and a predetermined (Base station) by the air interface (antenna 43a)
A wireless unit 43 for transmitting and receiving wireless signals to and from a human-machine interface (MMI) 44 having a liquid crystal display (LCD) 44a and dial keys 44b,
5a, a receiving speaker 45b, an audio codec 45 for performing A / D conversion of an analog audio signal transmitted and received, and an infrared controller 4 for transmitting and receiving an infrared signal to and from an external terminal
6 is comprised.

FIG. 2 shows a detailed configuration of the infrared controller 46 shown in FIG.
FIG. 3 is a diagram illustrating a U40 and an audio codec 45. As shown in FIG. 2, under control of the CPU 40, the infrared controller 46 includes a UART 46a that controls an interface with the audio codec 45, and a modulator 46 that modulates voice or data obtained through the UART 46a into an infrared signal.
b, a level controller 46c for controlling the output level of the infrared signal modulated by the modulator 46b in accordance with an instruction from the CPU 40, and a demodulator 46d for demodulating the infrared signal received from the external terminal.

Next, the operation of the mobile communication terminal with an infrared port will be described.

First, a procedure for finding a partner in infrared communication of the mobile communication terminal will be described with reference to FIG.

According to the infrared communication standard, one-to-one communication is performed after communication is started, but it is assumed that there are n terminals in the partner discovery procedure performed prior to the start of communication. FIG. 3 shows a sequence in which there are four mobile communication terminals A, B, C, and D, and the terminal A starts a partner discovery procedure before starting communication.

The terminal A transmits a command XID frame specified in the procedure for finding a partner. This XID frame includes a format identifier indicating a discovery procedure XID frame, and a slot identification number called a slot number at the beginning. The slot number of the XID frame transmitted by the terminal A to discover the partner is:
In the case of the sequence shown in FIG. 3, [0] to [7] are set in order and each XID frame is transmitted. The slot number of the last frame of the partner discovery procedure is [FF]. FIG. 3 shows a sequence in the case where the maximum slot is eight slots. The maximum slot can be selected from 1, 6, 8, and 16 depending on the system.

First, the terminal A transmits a frame including the slot number 0 as XID [0] in order to find a partner. The terminals B, C, and D generate random numbers from 0 to the maximum slot-1 to determine their own slot numbers. When receiving the XID frame including the same slot number as their own, the terminals B, C, and D respond to the response XID frame. I will send it back.

FIG. 3 shows a case where terminal B has slot number 2, terminal C has slot number 6, and terminal D has slot number 4. Terminals B, C, and D transmit XID [2], XID [4], and XID of the command XID frame from terminal A.
A response XID frame is returned for each of [6]. Terminal A can recognize that there are three communication partner terminals by receiving the response XID frame returned by another terminal in this series of discovery procedures.

When the terminal A has been found, the terminal A selects the communication partner and proceeds to the next connection procedure. In the connection procedure, negotiations such as a communication speed and communication conditions required for communication are performed.

As described above, the procedure for finding the communication partner is performed from the slot number [0] to [maximum slot-1].
The transmission of the XID frame including the slot numbers up to and the transmission of the XID frame with the slot number [FF] is a single partner discovery procedure. This partner discovery procedure is started from a higher layer at predetermined time intervals until a partner can be found or a predetermined time has elapsed.

Hereinafter, in FIG. 3, terminal A that has started the terminal discovery procedure will be referred to as a primary side, and terminals B, C, and D that have transmitted a response will be referred to as secondary sides. However, each of the terminals A, B, C, and D can be both a primary and a secondary. In general, a terminal that intends to communicate becomes the primary side, starts a partner discovery procedure, and starts selecting a communication partner.

Next, the communication partner discovery procedure of the primary mobile communication terminal shown in FIG. 3 will be described with reference to the flowchart shown in FIG. It should be noted that the communication partner discovery procedure shown in the flowchart of FIG.
Alternatively, it is executed as a subroutine in the processing procedure shown in FIG.

First, the CPU 40 performs an initialization process as follows.
Set the maximum number of slots. Since the slot number starts from 0, Ma for detecting the upper limit of the maximum number of slots is used.
The value of xSlot is set to [maximum slot-1] (step A1). Although the maximum number of slots differs depending on the system, for example, one of 1, 6, 8, and 16 is used.
In the example shown in FIG. 5, a description will be given assuming that the maximum number of slots is eight. Further, the CPU 40 includes a RAM 41
And an initial value 0 is set (Step A2).

In the initialization process, MaxSlot and Sl
After setting otCt, the CPU 40 sets X for the discovery procedure.
An ID command frame is transmitted (step A3).
As described in FIG. 3 in the XID frame,
A format identifier indicating a discovery procedure XID frame is prefixed with a slot discovery number called a slot number.

After transmitting the XID frame, a slot timer is started (step A4). The slot timer is a timer for waiting for an XID response frame from the partner terminal. The reception of the frame is waited until the slot timer times out. If the XID frame is received (step A8), the XID frame is stored and set by a flag or the like indicating that the reception has been performed (step A8).
9).

On the other hand, when the slot timer has timed out (step A5), the CPU 40 sets the SlotCt
Is checked to see if it is the same as MaxSlot (step A6). If they do not match, then SlotCt is incremented (step A10) and the next XID
A command frame is transmitted (step A3).

In the same manner, the next XID command frame is sequentially transmitted, and is stored when the XID response frame is received (steps A3 to A6, A8,
A9, A10).

In this way, by sequentially transmitting XID command frames, if SlotCt matches MaxSlot, the discovery procedure has been completed, so that the CPU 40 sets the XID frame with the slot number set to [FF]. Is transmitted (step A7), and the process of the partner discovery procedure ends.

Next, the primary operation of the mobile communication terminal according to the present embodiment will be described with reference to the flowchart shown in FIG. The process shown in the flowchart of FIG. 5 is executed when a communication start instruction is input through the man-machine interface 44 by, for example, operating the dial key 44b (step B1).

The level controller 46c provided in the infrared controller 46 shown in FIG. 2 is a module capable of controlling the intensity of the transmitted infrared ray in accordance with the instruction from the CPU 40. First, the CPU 40 controls the level control unit 46.
The transmission intensity of the infrared ray by c is set to Min (step B2). The transmission intensity Min indicates a preset minimum value of the infrared transmission intensity instructed to the level control unit 46c. That is, this means that the transmission intensity of the XID command frame transmitted in the subroutine (FIG. 4) of the first partner discovery procedure starts with Min.

Next, as described with reference to FIG. 4, after executing the subroutine of the partner discovery procedure (step B3), the CPU 40 receives an XID frame (step B4), and receives the XID response frame. It is determined whether or not it is valid (step B5). If it is valid, the process proceeds to the next step.

On the other hand, as a result of executing the partner discovery procedure, XI
If no D frame has been received (step B4) or if the received frame is not a valid response (step B5), the CPU 40 increases the intensity by one step unless the transmission intensity is the maximum value (Max). (Transmission strength =
(Transmission strength +1) (steps B6 and B7), a discovery procedure activation timer is started (step B8), and the discovery procedure is executed again after the timer times out (step B).
9). That is, if no partner is found in the first partner discovery procedure, the transmission strength is increased and the next discovery procedure is executed.

In FIG. 5, the operation is performed in which the infrared intensity is increased from transmission intensity Min to Max for each discovery procedure until the communication partner terminal can be found, and executed. The infrared intensity at the time when the communication partner terminal is found can be said to be the minimum transmission intensity required for performing infrared communication. Most mobile communication terminals operate on a battery (not shown), so that the power consumption of the battery is minimized by using the infrared intensity at the time when the communication partner terminal can be found. Can be.

It should be noted that, as described above, not only the battery drive but also the commercial power drive may be possible depending on the place of use. Therefore, when the commercial power supply can be driven, communication can be performed in a favorable communication environment by always using the maximum transmission intensity regardless of the power consumption of infrared transmission. Hereinafter, the operation in the case where the commercial power supply can be used will be described with reference to the flowchart shown in FIG.

FIG. 6 shows that the method of stepwise increasing the transmission intensity shown in FIG. 5 is executed only when the battery is driven, and the transmission intensity is set to Max in an environment using an external power supply such as a commercial power supply. It is a flowchart which shows a method. That is, only when it is necessary to perform infrared communication with low power consumption, the present invention is implemented in which the transmission intensity is increased stepwise.

In the processing in each step of the flowchart shown in FIG. 6, step C1 is the same as step B in FIG.
1. Steps C5 to C11 correspond to steps B3 to B9 in FIG.
, And a detailed description thereof will be omitted.

In the process shown in FIG. 6, it is determined whether or not the battery is being driven (step C).
2) There are two types, that is, the transmission intensity is increased stepwise from the transmission intensity Min to select the optimum value (step C3), and communication is performed with the Max value (step C4). However, in the process of checking whether or not to run the battery after the start of communication in step C2, the remaining battery level is checked.
As a result, when the remaining battery level is equal to or less than the predetermined value, a method of increasing the transmission intensity in a stepwise manner may be executed, and when the remaining battery level is equal to or more than the predetermined value, the transmission intensity may be set to Max.

Further, it may be executed by changing the value of Min, which is the initial value of the transmission intensity, according to the remaining amount of the battery. That is, when the remaining battery charge is equal to or greater than a predetermined value, Mi
n when the remaining battery charge is less than or equal to a predetermined value from the value of n
By lowering the value of n, a lower level of infrared transmission intensity can be set, and the power consumption of the battery can be reduced.

The operation of the mobile communication terminal on the communication start-up side, ie, the primary side, has been described above. The operation of the mobile communication terminal on the secondary side will be described below.

Referring to a flowchart shown in FIG. 7, a procedure for finding a communication partner of the secondary mobile communication terminal shown in FIG. 3 will be described. The communication partner discovery procedure shown in the flowchart of FIG. 7 is executed as a subroutine in the processing procedure shown in FIG. 7, FIG. 8, or FIG.

As will be described later, this subroutine is called when an XID command frame for a discovery procedure is received. The operation of the secondary mobile communication terminal is shown in FIG.
As described in, when the slot number of the XID command frame in the discovery procedure activated by the primary-side mobile communication terminal matches the own slot number, the XID frame of the response is returned.

First, the CPU 40 determines its own slot number n by generating a random number from [0] to [maximum number of slots-1] (step D1). CPU
After determining the slot number n for the communication partner discovery procedure (step D1), 40 checks the slot number area of the received XID command frame.

If the slot number is [FF], it is the end frame of the communication partner discovery procedure, so that the procedure ends, and the subroutine ends (steps D2 and D8).

On the other hand, if the slot number is not [FF], the CPU 40 compares its own slot number n with the slot number of the XID command frame (step D).
3) If they match, an XID response frame is generated and transmitted (step D4). If they do not match, the reception of the next XID command frame is detected (step D5). If an XID command frame other than the discovery procedure has been received (steps D6 and D7), the subroutine ends and the process returns to the main (step D9).

If there is no error in the received frame from the mobile communication terminal on the primary side, X of the slot number [FF]
Until the ID command frame is received (step D2), the XID response frame of the slot number n is transmitted once to complete the discovery procedure.

Next, the secondary operation of the mobile communication terminal according to the present embodiment will be described with reference to the flowchart shown in FIG.

First, the CPU 40 controls the level control section 46c.
Is set to [Min-1] (step E1). The transmission intensity = Min-1 indicates the minimum value of the preset infrared transmission intensity instructed to the level control unit 46c shown in FIG. 2, as in the case of the primary operation described above. In the process shown in FIG. 8, the initial value of the infrared transmission intensity is set to Min-1.
The reason is that the transmission intensity is increased by one before the subroutine call of the communication partner discovery procedure at the time of secondary, so that the infrared transmission intensity in the first discovery procedure is set to Min.

Next, when an XID command frame for a discovery procedure is received from the primary mobile communication terminal (steps E2, E3, E4), the CPU 40 executes the above-described secondary discovery procedure subroutine shown in FIG. (Step E7). In addition, the designation of the infrared transmission intensity
If the transmission intensity is not Max immediately before performing the subroutine call (step E5), the transmission intensity is incremented by 1 and the subroutine is executed (step E6).

When the partner discovery procedure succeeds, a frame other than the discovery procedure XID command frame is transmitted from the primary mobile communication terminal. CPU40
Proceeds to the next procedure control because the next discovery procedure frame has been received (steps E2 to E4, E8). The discovery procedure ends when the XID response frame transmitted from the secondary mobile communication terminal normally reaches the primary mobile communication terminal. In the case where the reception procedure is not normally performed, the discovery procedure is restarted by the mobile communication terminal on the primary side.

In the discovery procedure shown in the flow chart of FIG. 8, every time the discovery procedure is started by the primary-side mobile terminal device, the transmission intensity of the XID response frame increases stepwise by +1 to [Max].
Since the frame for the next procedure has been received, the success of the discovery procedure can be detected, and the process can proceed to the next procedure. The infrared transmission intensity after the discovery procedure is executed at the transmission intensity at the time when the discovery procedure was successful. The infrared transmission intensity at the time when the discovery procedure succeeds is the minimum transmission intensity for executing the discovery procedure, and may be set to be lower than an optimal value in consideration of an error rate. Considering such a case, a value obtained by minimizing the transmission intensity selected in the discovery procedure and increasing the intensity by a predetermined value from this value may be the optimum transmission intensity in some cases.

Next, an example of performing infrared transmission after the discovery procedure at a transmission strength higher by 1 than the transmission strength determined by the discovery procedure shown in FIG. 8 will be described with reference to the flowchart shown in FIG. The processing in each step of the flowchart shown in FIG. 9 includes steps F1 to F4 and F9.
However, since they respectively correspond to the processing of steps E1 to E4 and E8 in FIG. 8, detailed description will be omitted.

In the process shown in FIG. 9, the CPU 40
When the discovery procedure frame is received from the mobile communication terminal on the primary side (step F4), an execution subroutine (secondary side) of the partner discovery procedure is executed (step F5),
If the transmission intensity has not reached Max after the discovery procedure (Steps F6 and F7), the transmission intensity is incremented by 1 to control the level control unit 46c (Step F8).

As described above, the infrared transmission intensity at the time of the success of the discovery procedure is set to the next level and the level controller 46c is controlled to determine whether or not the infrared transmission intensity at the time of the success of the discovery procedure has received infrared light on the infrared receiving side. Even if the threshold level is close to the threshold level, transmission is performed with the transmission intensity level raised by a predetermined level, so that stable transmission and reception of infrared rays can be performed, and subsequent occurrence of a procedure error can be prevented.

In the above description, the control method for determining the infrared transmission intensity from the level control unit 46c by increasing the infrared intensity step by step for each partner terminal discovery procedure has been described. In the case of a mobile communication terminal, the infrared intensity is set to a maximum value Max as described below.
It is also possible to use a method of gradually lowering the number.

FIG. 10 shows a flowchart of control for reducing the infrared intensity from the initial value Max for each partner terminal discovery procedure.

First, when a communication start instruction is input (step G1), the CPU 40 sets the transmission intensity of infrared rays by the level control unit 46c to Max (step G1).
2). The transmission intensity Max indicates a preset maximum value of the infrared transmission intensity instructed to the level control unit 46c. In other words, this means that the transmission intensity of the XID command frame transmitted in the subroutine (FIG. 4) of the first partner discovery procedure starts with Max.

Next, as described with reference to FIG. 4, the CPU 40 executes the subroutine of the partner discovery procedure (step G3), receives an XID frame (step G4), and receives the XID response frame. It is determined whether or not the terminal is valid (step G5). If the terminal is valid, a flag indicating that the terminal discovery procedure has been successfully completed is set in the RAM (step G6). Thereafter, if the transmission intensity is not the minimum value (Min), the CPU 40 lowers the intensity by one step (transmission intensity = transmission intensity−1) (step G8), starts a discovery procedure activation timer (step G9), and After the timeout, the discovery procedure is executed again (step G10).

As a result of executing the partner discovery procedure, if no XID frame has been received (step G4) or if the received frame is not a valid XID response frame (step G5), the previous terminal discovery procedure is transmitted. It is likely that the terminal discovery procedure was successful in strength. That is, the CPU 40 checks the flag set in the RAM for which the terminal discovery procedure has been successful, and if the terminal discovery procedure has been successful (step G11), proceeds to the next procedure.

As described above, by performing the control shown in the flowchart of FIG.
Optimum transmission intensity can be obtained by lowering to n. Naturally, the next procedure cannot be executed with the transmission strength at the time when the discovery procedure failed, so the transmission strength used in the next procedure is set to the transmission strength at the time of successful terminal discovery or set higher than that And

In the above-described embodiment, the mobile communication terminal has been described as an example. However, it is obvious that the present invention can be applied to a PDA or a portable personal computer that is battery-powered and has an infrared interface.

In the above-described embodiment, the intensity of infrared transmission from the level control unit 46c is changed in units of +1. However, in practice, the same intensity is repeated n times to perform the discovery procedure. Thereafter, the transmission intensity may be changed in increments of +1 or the transmission intensity may be controlled according to a predetermined change rate.

[0069]

As described above, according to the present invention, in a communication terminal having an external port for infrared communication, the subsequent communication is performed in a standard procedure for discovering a partner terminal. It is possible to determine the optimum infrared intensity. By setting the infrared transmission intensity to the minimum necessary value, the current consumption of the infrared transmission unit can be reduced, and the battery driving time of the entire terminal can be increased.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a mobile communication terminal with an infrared port according to an embodiment.

FIG. 2 is a block diagram showing a detailed configuration of an infrared controller 46 shown in FIG.

FIG. 3 is a diagram showing a sequence for explaining a partner discovery procedure in infrared communication of the mobile communication terminal.

FIG. 4 is a flowchart illustrating a communication partner discovery procedure of the primary-side mobile communication terminal.

FIG. 5 is a flowchart for explaining an operation of the mobile communication terminal in a primary mode.

FIG. 6 is a flowchart for explaining the operation of the mobile communication terminal in the primary mode when commercial power supply driving is also available.

FIG. 7 is a flowchart for explaining a communication partner discovery procedure of the secondary mobile communication terminal.

FIG. 8 is a flowchart for explaining a secondary operation of the mobile communication terminal.

FIG. 9 is a graph showing the transmission strength determined by the discovery procedure shown in FIG.
9 is a flowchart for explaining an example of performing infrared transmission after the discovery procedure at one high transmission intensity.

FIG. 10 is a diagram showing a flowchart of control for reducing the infrared intensity from an initial value Max for each partner terminal discovery procedure.

FIG. 11 is a diagram showing a connection example between a conventional mobile communication terminal and an external terminal.

FIG. 12 is a diagram showing an example of connection with an external terminal via an infrared interface.

FIG. 13 is a flowchart for explaining a conventional mobile communication terminal discovery procedure.

[Explanation of symbols]

 40 CPU 41 ROM / RAM 42 Baseband 43 Radio unit 43a Antenna 44 Man-machine interface (MMI) 44a Liquid crystal display (LCD) 44b Dial keys 45 Voice codec (CODEC) 46 Infrared controller 46a UART 46b Modulation unit 46b Demodulation unit 46c Level control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04L 29/12 H04M 1/737

Claims (7)

[Claims] 1. A communication terminal that communicates with an external terminal via an infrared port, comprising: before communication with the external terminal, a predetermined command frame for discovering a partner terminal on the infrared interface;
First means for transmitting from the infrared port at a predetermined infrared transmission intensity when executing a partner terminal discovery procedure repeated at predetermined time intervals; and an external terminal corresponding to a predetermined command frame transmitted by the first means. A second means for receiving a response frame transmitted from the mobile terminal; and, if a response frame cannot be received by the second means, the infrared transmission intensity of the first means is determined by a procedure for finding a partner terminal after a predetermined time. When a response frame transmitted from an external terminal corresponding to the predetermined command frame is received by the second unit, a predetermined command frame is transmitted from the time of the previous transmission. The procedure following the procedure for finding the partner terminal after the infrared transmission strength that transmitted the specified command frame Communication terminal, characterized by comprising a third means for fixing as infrared transmission intensity Oite used. 2. A communication terminal for communicating with an external terminal via an infrared port, comprising: before communication with the external terminal, a predetermined command frame for finding a partner terminal on the infrared interface;
First means for transmitting from the infrared port at a predetermined infrared transmission intensity when executing a partner terminal discovery procedure repeated at predetermined time intervals; and an external terminal corresponding to a predetermined command frame transmitted by the first means. A second means for receiving a response frame transmitted from the mobile terminal; and, if a response frame can be received by the second means, in a procedure for discovering a partner terminal after a predetermined time, the infrared transmission intensity by the first means is set to the previous value. When a predetermined command frame is transmitted lower than the time of transmission and a response frame transmitted from an external terminal corresponding to the predetermined command frame is received by the second unit, at this time, the predetermined frame is transmitted by the first unit. Infrared transmission that transmitted the command frame of Communication terminal, characterized by comprising a third means for fixing as an infrared transmission strength to use. 3. A communication terminal that communicates with an external terminal via an infrared port, wherein a communication partner terminal discovery procedure that is repeated every predetermined time for discovering a communication partner terminal on the infrared interface is performed prior to communication with the external terminal. A transmission unit that, when activated from an external terminal, receives a predetermined command frame from the external terminal, and transmits a predetermined response frame to the reception at a predetermined infrared transmission intensity from the infrared port; Determining means for determining whether the external terminal has re-executed the partner discovery procedure after a predetermined period of time or has proceeded to the next step, depending on the type of the command frame received by the means; and If it is determined that the means has been re-executed, the infrared transmission intensity for the command frame of the partner discovery The transmitting means is further raised, and when the determining means determines that the procedure has proceeded to the next step, fixing means for fixing the infrared transmission intensity at which the transmitting means transmitted the response frame at this time is provided. A communication terminal. 4. The third means, when a response frame is received by the second means, makes a predetermined value higher than an infrared transmission intensity at which a predetermined command frame is transmitted by the first means at this time. The communication terminal according to claim 1, wherein: 5. The method according to claim 1, wherein when the response frame is not received by the second unit, the third unit is higher by a predetermined value than an infrared transmission intensity at which a predetermined command frame is transmitted by the first unit. The communication terminal according to claim 2, wherein: 6. The fixing means, when the determination means determines that the procedure has proceeded to the next step, increases the infrared transmission intensity at which the transmission means transmitted the response frame by a predetermined value at this time. The communication terminal according to claim 1, wherein: 7. The infrared transmission intensity is fixed only when the battery is driven or when the remaining battery power is lower than a predetermined value.
Communication terminal as described.