Abstract:
A wireless communication device supporting at least non-connection communication and a control method therefore are disclosed. It is determined whether a request for non-connection communication occurs and, when the communication request occurs during an online mode, the online mode is changed to an offline mode in response to occurrence of the communication request, and then the non-connection communication is started. When the communication request occurs, the Auto-Find-IAS function is disabled to prevent undesired connection to another device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to wireless data communications techniques, and in particular to a communication protocol for a wireless data communication device supporting at least non-connection data communication. 
     2. Description of the Related Art 
     As a communication protocol, connection and non-connection communication protocols have been known. In the connection communication protocol, one party identifies another party to communicate with before communicating with the identified party, which is called “Connection Write” in the IrMC (Infrared Mobile Communications) standard (see “Telecom Specification”). The IrMC standard has been introduced by the Infrared Data Association (IrDA), defining common data exchange formats and protocols for interoperability in mobile communications devices such as a mobile telephone, a mobile personal computer, and the like. In the non-connection communication protocol, on the other hand, the one party transmits data to another party in only one direction without identifying the destination, which is called “Ultra Write” in the IrMC standard. 
     A mobile communication device having the infrared communication function as mentioned above alternately performs ON-LINE operation (search mode) and OFF-LINE operation (off mode) in a predetermined period. More specifically, in the search mode, the device transmits a Query signal for informing another device of its own information such as device name, and then changes into normal discovery mode (NDM) to wait for a Query signal to be received from another device. According to IrMC standard, the Query signal is supposed to be consecutively transmitted three times before the NDM. 
     When receiving a Ouery signal from another device during the NDM period, the device determines whether the other device is permitted to be connected. If permitted, a connection request signal is transmitted to the other device or it may be received from the other device. Since the Auto-Find-IAS of a mobile communication device conforming to the IrMC standard defaults to “Enable”, the IAS (Information Access Service) search is automatically started when receiving the connection request signal from the other device. In other words, upon reception of the connection request, the device automatically and periodically transmits IAS to the other device to determine whether communication can be established between them. 
     According to the non-connection communication protocol, however, the non-connection communication cannot be performed during the ON-LINE operation. Therefore, as shown in FIG. 4B, when a non-connection communication request occurs during the ON-LINE operation, an error state is generated and thereby the non-connection communication is not permitted until the ON-LINE operation has been completed. 
     Further, in the case where the device has been discovered by the other device receiving the Query signal transmitted by the device, the device automatically transmits the IAS to the other device when receiving the connected request from the other device. Therefore, even if the other device is an undesired device to communicate with, the IAS is automatically transmitted to the other device. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a wireless non-connection data communication apparatus and a control method therefor, which can promptly respond to a non-connection communication request. 
     Another object of the present invention is to provide a wireless non-connection data communication apparatus and a control method therefor, which can ensure security in communications. 
     According to the present invention, a control method for a wireless communication device which has an online mode and an offline mode and supports at least non-connection communication which is allowed in the offline mode, comprises the steps of: a) determining whether a request for the non-connection communication occurs; b) when the communication request occurs during the online mode, changing the online mode to the offline mode in response to occurrence of the communication request; and c) starting the non-connection communication. 
     When a non-connection communication request occurs during connection communication with another wireless communication device, it is preferably that the connection communication is disconnected and the non-connection communication is started in response to the non-connection communication request. 
     According to anther aspect of the present invention, a control method for the wireless communication device comprises the steps of: a) determining whether a request for the non-connection communication occurs; b) when the communication request occurs, setting a communication mode to a no-response mode in response to occurrence of the communication request, wherein the no-response mode provides no response to a request received from another communication device; c) when the communication request occurs during the online mode, changing the online mode to the offline mode in response to occurrence of the communication request; and d) starting the non-connection communication. 
     The no-response mode may be set by disabling an Auto-Find-IAS function conforming to IrMC (Infrared Mobile Communications) standard. 
     Since the online operation is halted when the non-connection communication request occurs, the non-connection communication can be promptly started, resulting in reduced power consumption. 
     Further, since the apparatus is set to the no-response mode in response to the non-connection communication request, undesired connection can be prevented, resulting in Improved security. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a diagram showing an infrared communication system implementing an infrared data communication method according to the present invention; 
     FIG. 1B is a schematic block diagram showing an operation of the infrared communication system of FIG.  1 A: 
     FIG. 2 is a block diagram showing an infrared communication device used in the infrared communication system of FIG. 1B; 
     FIG. 3 is a flow chart showing an infrared non-connection communication method according to a first embodiment of the present invention; 
     FIG. 4A is a time chart showing an operation of the first embodiment; 
     FIG. 4B is a time chart showing a conventional infrared communication method; 
     FIG. 5 is a sequence diagram showing an operation of a second embodiment of an infrared communication method according to the present invention; 
     FIG. 6 is a sequence diagram showing an operation of the first and second embodiments; 
     FIG. 7 is a flow chart showing an infrared non-connection communication method according to a third embodiment of the present invention: 
     FIG. 8 is a time chart showing an operation of the third embodiment; and 
     FIG. 9 is a sequence diagram showing an operation of the third embodiment as shown in FIG.  8 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1A, a mobile telephone  10  and a personal computer (PC)  11  can communicate with each other by infrared rays according to connection and non-connection communication protocols. Such a device having an infrared communication function is not restricted to the mobile telephone  10  and PC  11 . Other information processing devices may be used. 
     As shown in FIG. 1B, the mobile telephone  10  and PC  11  are provided respectively with IR communication devices  12  and  13  to perform IR communications. The mobile telephone  10  is provided with a processor (CPU)  14 , which controls the operations of the mobile telephone. In this system, a memory  15  can be detachably connected to the mobile telephone  10  through a device  16  The processor  14  can access the contents of the memory  15 . Similarly, the PC  11  is provided with a processor (CPU)  17 , which controls the operations of the PC. In this system, a memory  18  can be detachably connected to the PC  11  through a device  19 . The processor  17  can access the contents of the memory  18 . 
     Hereinafter, taking the above system as shown in FIG. 1B as an example, the details of the non-connection infrared communication from the mobile telephone  10  to the PC  11  according to the present invention will be described with reference to the drawings. 
     FIG. 2 shows the internal circuit of a communication device which may be one of the mobile telephone  10  and the PC  11 . The communication device is provided with an IrDA module  20  for transmitting and receiving an infrared signal. The IrDA module  20  includes an LED connected to an LED driver  201  and a photo detector connected to a receiver  202 . The communication device is further provided with a modem  21  through which the IrDA module  20  is connected to a processor  22 . The modem  21  includes an encoder  203  and a decoder  204  which are connected to the LED driver  201  and the receiver  202  of the IrDA module  20 , respectively. The IrDA module  20  and the modem  21  are controlled by the processor  22 . 
     The processor  22  may be a program-controlled processor such as CPU on which control programs run to do the entire control of the communication device. The control programs stored in a read-only memory (ROM)  23  include an infrared communication control program according to the present invention. The processor  22  performs the IR communication control using a connection information table  24  stored in a random access memory (RAM) and inputs an instruction such as a non-connection communication request from a user through an input device  25  such as a keypad or a pointing device. The connection information table  24  contains information of devices connected on logical data paths and information of class and attribute of applications. The connection information table  24  is used for search and discovery negotiation in ON-LINE operation. 
     The communication protocol according to the present invention will be described in detail. 
     Referring to FIG. 3, in the case of waiting state (step S 301 ), the processor  22  checks whether a non-connection communication request is received from the input device  25  (step S 302 ). When receiving the non-connection communication request (YES in step S 302 ), the processor  22  sets the Auto-Find-IAS to “Disable” (step S 303 ). This causes the IAS to be inhibited from being sent back to the other device in response to a connection request received from the other device. 
     Thereafter, it is further determined whether the ON-LINE operation is being done (step S 304 ). When in ON-LINE operation (YES in step S 304 ), the processor  22  sends an ON-LINE operation halt request to the IrDA module  20  (step  5305 ). When in OFF-LINE operation (NO in step S 304 ) or after the ON-LINE operation halt request has been sent to the IrDA module  20  (step S 305 ), the processor  22  sends a non-connection communication request to the IrDA module  20  (step S 306 ) and then the non-connection data communication is started (step S 307 ). When the non-connection data communication has been completed, the processor  22  is changed to the waiting mode. In this way, the non-connection communication control is performed as shown in FIG.  4 A. 
     As shown in FIG. 4A, the processor  22  alternately performs ON-LINE operation ( 401 ,  403 ) and OFF-LINE operation ( 402 ,  404 ) at predetermined intervals. In each ON-LINE operation, the processor  22  produces a query signal Q which is to be transmitted. The query signal Q conveys information of the communication device itself, for example, Device Nick Name including the IrMC function level of the communication device itself. Thereafter, the processor  22  changes the operation mode to the normal discovery mode (NDM) to wait for a query signal Q of the other device and, when receiving the query signal Q of the other device, performs the response protocol control for searching, selecting, and current connection control in the NDM. In FIG. 4A, ON-LINE operations  401  and  403  indicate that no communication device to communicate with is found. 
     Since a non-connection communication request is made by a user, there are cases where the non-connection communication request occurs during an ON-LINE operation. When receiving the non-connection communication request from the input device  25 , the processor  22  forces the current ON-LINE operation to be turned off, that is, changes ON-LINE to OFF-LINE (S 305 ). Therefore, a non-connection communication operation  405  can be started immediately after the non-connection communication request occurs. 
     In contrast, as shown in FIG. 4B, according to the prior art, when a non-connection communication request occurs during the ON-LINE operation  403 , the non-connection communication is not permitted until the ON-LINE operation  303  has been completed, resulting in delayed data transmission, for example, a delay of several seconds. According to the embodiment of the present invention, prompt non-connection data transmission (for example, a delay of several milliseconds) can be performed even if the non-connection communication request occurs during the ON-LINE operation  403 . 
     Further, when the non-connection request occurs, the Auto-Find-IAS is set to “Disable” (step S 303 ). Therefore, the IAS is inhibited from being sent back to the other device in response to a connection request received from the other device. This causes the discovery by the other device to be prevented. 
     Referring to FIG. 5, when receiving a query signal Q from another device during the ON-LINE period  501 , the device performs discovery negotiation including NDM  503  and query transmission  504  by referring to the connection Information table  24 . When receiving the non-connection communication request from the input device  25  during the ON-LINE period  501 , the processor  22  forces the current ON-LINE operation to be turned off, that is, changes ON-LINE to OFF-LINE (S 305 ). Therefore, a non-connection communication operation  405  can be started immediately after the non-connection communication request occurs. 
     Further, when the non-connection request occurs, the Auto-Find-IAS is set to “Disables” (step S 303 ). Therefore, the IAS is inhibited from being sent back to the other device in response to a connection request received from the other device. 
     Referring to FIG. 6, assuming that the ON-LINE operation is being done (S 304 ) and a non-connection communication request is made by a user (S 302 ). When receiving the non-connection communication request from the input device  25 , the processor  22  sends a discovery halt request to the IrDA module  20  to stop the search operation (S 305 ). Thereafter, the processor  22  sends a communication request to the IrDA module  20  to start the non-connection communication (S 306 , S 307 ). 
     Referring to FIG. 7, the processor  22  performs the communication protocol control when a non-connection communication request occurs. In the case of connection state (step S 701 ). the processor  22  checks whether a non-connection communication request is received from the input device  25  (step S 702 ). When receiving the non-connection communication request (YES in step S 702 ), the processor  22  sets the Auto-Find-IAS to “Disable” (step S 703 ). As described before, this causes the IAS to be inhibited from being sent back to the other device In response to a connection request received from the other device. 
     Thereafter, the processor  22  sends an IrDA disconnection request to the IrDA module  20  (step S 704 ). After the operation mode is changed from the connection state to the OFF-LINE mode, the processor  22  sends a non-connection communication request to the IrDA module  20  (step S 705 ) and then the non-connection data communication is started (step S 706 ). 
     When the non-connection data communication has been completed, the processor  22  can be changed to the waiting mode. Alternatively, reconnection to the previous opposite party can be also made. In the case of the reconnection control, the ROM  23  stores the reconnection control program for restoring the previous connection and restarting the data transfer. 
     Referring to FIG. 8, when receiving a query signal Q from another device during the NDM period, the device performs discovery negotiation and query transmission during the ON-LINE period  801  by referrlng to the connection information table  24 . When the negotiation has been successfully completed, the mode is changed to the connection state In which the device can communicate with the specific device during the connection period  802 . When receiving the non-connection communication request from the input device  25  during the connection state, the processor  22  sets the Auto-Find-IAS to “Disable” (step S 703 ) and sends a disconnection request to the IrDA module  20  (S 704 ), so that the non-connection communication can be performed without discovered by another device. Therefore, a non-connection communication operation can be started immediately after the non-connection communication request occurs. 
     Referring to FIG. 9, when the non-connection communication is requested by the user through the input device  25  during the connection state, the processor  22  sets the Auto-Find-IAS to “Disable” (step S 703 ) and sends a disconnection request to the IrDA module  20  (S 704 ). When receiving the disconnection request from the processor  22 . the IrDA module  20  transmits the disconnection request to the opposite party. After the connection to the opposite party has been disconnected, the processor  22  sends a communication request to the IrDA module  20  to start the non-connection communication (S 706 ). 
     As described above, according to the present invention, the non-connection communication can be performed smoothly in response to the user&#39;s request, resulting in reduced power consumption. In other words, priority is given to the non-connection communication Further, since the Auto-Find-IAS is set to “Disable” in response to the non-connection communication request, undesired connection can be prevented, resulting in improved security.