PORTABLE COMMUNICATION TERMINAL WITH INFRARED LINK

Abstract: A portable communication terminal comprising a user interface, a radio transceiver for communicating with a telecommunication network and an infrared transceiver by which an infrared communication link can be established with a local terminal, wherein, in response to a user input via the user interface, the portable terminal monitors signals received by the infrared transceiver with a view to establishing the infrared link.

Description: PORTABLE COMMUNICATION TERMINAL WITH INFRARED LINK The present invention relates to a portable communication terminal. It is known to use a radiotelephone as a gateway to the public telephone switching network (PTSN) for a local data terminal such as, for example, a PC, a laptop PC, a personal organiser and the like. Interfacing between the radiotelephone and the local data terminal is sometimes accomplished via an infrared link. The present invention has particular, but not exclusive, application to the management of the infrared link in the above and similar circumstances. With this in mind, in one aspect the present invention provides a portable communication terminal, comprising a user interface, a radio transceiver for communicating with a telecommunication network, and an infrared transceiver by which an infrared communication link can be established with a local terminal, wherein, in response to a user input via the user interface, the portable terminal monitors signals received by the infrared transceiver with a view to establishing the infrared link. By limiting the occasions when the portable communication terminal seeks to establish the infrared link only to those occasions when a user input indicates that the user is requesting that the infrared link is established, power savings resulting from reduced use of the infrared transceiver can be achieved. Preferably, if no infrared link is established within a predetermined interval, for example 20 seconds, the monitoring activity of the infrared transceiver is discontinued. By limiting the monitoring activity in this way, further power savings can be achieved in circumstances where for some reason it has not been possible to establish the infrared link within a reasonable period. - In another aspect, the present invention provides a method of communicating between two terminals via an infrared link in which at least one of the terminals monitors for infrared activity in response to a user input via its user interface. Exemplary embodiments of the invention are hereinafter described with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of a cellular mobile telephone; Figure 2 shows a diagram of the main features in the telephone of Figure 1 ; and Figure 3 shows a diagram of the telephone of Figure 1 establishing an infrared link with a PC. The telephone shown in Figure 1 is a cellular mobile telephone 1 having an 'A 1 or front cover 3a and a 'B' or rear cover 3b powered by a rechargeable battery pack 2. The user interface of the telephone 1 comprises a liquid crystal display 5 having backlighting, a microphone 7, a loudspeaker 8 and a keypad 6. The keypad 6 comprises two groups of keys: a first group of alphanumeric keys 6a for entering telephone numbers and text data, and a second group of functions keys 6b for enabling/disabling functions of the telephone 1 or causing operations of the telephone 1 to be executed. Referring to Figure 2, the telephone includes a transceiver 9 for transmitting and receiving signals to and from a cellular telecommunication network. A controller 4 in the form of a microprocessor controls the operation of the telephone 1 including its user-interface, a memory 14, the radio transceiver 9 and an infrared transceiver 16 ( not visible in the Figure 1 view). One of the function keys 66, the ON/OFF key, can be depressed for a relatively long duration (>1 second) to cause the controller 4 to switch the telephone 1 between an off mode in which negligible battery power is consumed to an on mode. In an on mode, the telephone 1 can be considered to be in any one of a call processing mode, an active standby mode or a passive standby mode. In the call processing mode, a telephone call is conducted over the (radio) air interface via the radio transceiver 9. Due to heavy use of the air interface during calls, this mode results in high power consumption. In active standby mode, power is consumed as a result of certain user-interface functions of the telephone 1 and the radio transceiver 9. In passive standby mode, power is consumed substantially only as a result of the radio transceiver 9. In either kind of standby mode, the power consumption of the radio transceiver 9 arises out of the need to access the air interface to maintain registration with the cellular network, specfically, for example, to watch for incoming calls and hand over from one cell to another as the telephone 1 changes location, even though no calls traffic is being processed. The difference between the two standby modes lies in the fact that in active standby mode, the user is able to make use of the keypad 6 and the display 5 in order to review or alter the contents of the memory 14, for example, with a view to adding a number to the telephone number store or altering a control setting of the telephone 1. In this active standby mode, the backlighting of the display 5 is activated. In order to move between the active standby mode and the passive standby mode, the keys MENU and are pressed sequentially. In passive standby mode, the display 5 and its backlighting are inactive as is the keypad (except, of course, in response to the sequential pressing of the MENU and " keys). While in passive standby mode, if an incoming call is received, then depression of any key accepts the call and thus the telephone 1 enters the call processing mode. Figure 3 shows the telephone 1 and a local data terminal in the form of a PC 50. The PC comprises a keyboard 52, a cathode ray visual display 54 and an infrared transceiver 18. In order to send a fascimile document prepared on the PC 50 using the telephone 1 as a gateway to the PTSN, the data defining the fascimile needs to be transferred to the telephone 1 via their respective infrared transceivers 16,18. The PC 50 and the telephone 1 are arranged such that their infrared transceivers 16, 18 are in line of sight relation with each other. Initially, the telephone 1 is in passive standby mode. On sequentially pressing the MENU and keys, the telephone 1 switches from passive standby mode to active standby mode. Also, the infrared transceiver 16 of the telephone 1 starts to monitor or poll for incoming infrared signals with a view to establishing an infrared link between the telephone 1 and the PC 50. If during a 20 second period, the PC 50 transmits signals which seek to create an infrared link, then an infrared link is established permitting the fascimile document data to be transmitted. If, however, after the 20 second period, no link is established then the telephone 1 discontinues monitoring the incoming infrared signals. It will thus be appreciated that the functional effect of sequentially pressing the MENU and * keys is two fold, firstly, to switch the telephone 1 from passive standby to active standby mode, but also secondly to start the monitoring activity. In other embodiments, the user input for the infrared transeiver 16 to start to monitor infrared activity can be actions which are dedicated to or have the sole functional effect of triggering the monitoring activity. Examples include the selection of an option from a menu, the depression of predetermined keys, either in a defined sequential ordei or simultaneously, or a voice command. When the infrared transceiver 16 is not polling for infrared activity, it can be either 'on' but not consuming much power by virtue of not actively polling for infrared activity, or shut-down into a power-saving or standby mode where it uses negligible power. In another embodiment, when the telephone 1 is in the off mode, the trigger to start monitoring infrared activity can be provided by depression of the ON/OFF key for a relatively short duration which is insufficient to place the telephone 1 into on mode. If during the 20 second interval, no infrared link is established then the monitoring activity is discontinued and the telephone 1 remains in off mode. On the other hand, if an infrared link is established, then the telephone 1 is switched to the on mode.

Claims: CLAIMS 1. A portable communication terminal, comprising: a user interface; a radio transceiver for communicating with a telecommunication network; and an infrared transceiver by which an infrared communication link can be established with a local terminal; wherein, in response to a user input via the user interface, the portable terminal monitors signals received by the infrared transceiver with a view to establishing the infrared link. 2. A portable communication terminal as in Claim 1 , wherein, if no infrared link is established within a predetermined interval, said monitoring is discontinued. 3. A portable communication terminal as in Claims 1 or 2, wherein the user input comprises the depression of predetermined keys. 4. A portable communication terminal as in any of Claims 1 to 3, wherein the user input comprises a voice command. 5. A portable communication terminal as in Claims 3 or 4, wherein the user input has the sole functional effect of triggering said monitoring. 6. A portable communication terminal as in Claims 3 or 4, wherein the user input has the functional effect of triggering said monitoring and changing the mode of operation of the portable terminal. 7. A portable communication terminal constructed, arranged and adapted to oπerate substantially as hereindescribed with reference to the accompanying drawings.

Inventors: KERAI KANJI, SCALES JAMES, KERAI, KANJI, SCALES, JAMES
Applicants: KERAI KANJI, NOKIA MOBILE PHONES LTD, SCALES JAMES, KERAI, KANJI, NOKIA MOBILE PHONES LIMITED, SCALES, JAMES
Application year: 1998
Main classification: H04M1
IPC codes: H04B10, H04M1, H04M11