WO2009026963A1

WO2009026963A1 - Remote control system

Info

Publication number: WO2009026963A1
Application number: PCT/EP2007/059077
Authority: WO
Inventors: Joost Van Der Made; Eric Pite; Mark Gretton
Original assignee: Tomtom International B.V.
Priority date: 2007-08-30
Filing date: 2007-08-30
Publication date: 2009-03-05
Also published as: AU2007358111A1; TW200909780A

Abstract

A system for controlling a controllable device, in particular a navigation device, comprises a controllable device (450) comprising a user input (460), a controller (452) and a wireless communications interface (454). A remote control device (400) comprises a user input (410), a controller (402) and a wireless communications interface (404). The remote control device (400) transmits a pairing request to the controllable device. In response to receiving a confirmation, it pairs with the controllable device. In response to a user activation of the user input, it transmits a command to the paired controllable device. The controllable device (450) receives the pairing request from the remote control device. It enables a user to allow or reject the pairing request by means of a user input (460). In response to the user allowing the pairing request, it transmits the confirmation to the remote control device and pairs with it. In response to receiving a command from the paired remote control device (400), it executes the command.

Description

REMOTE CONTROL SYSTEM

FIELD OF THE INVENTION

The invention relates to a system and method for controlling a controllable device, in particular a navigation device. The invention also relates to a remote control device and to a controllable device. The invention also relates to a method and to a computer program product.

BACKGROUND OF THE INVENTION

GPS based devices are well known and are widely employed as navigation systems, in particular in-car navigation devices. Such devices often integrate a GPS receiver into a computing device that is programmed with a map database and that can generate navigation instructions on a display. The term 'navigation device' refers to a device that enables a user to navigate to a pre-defined destination. The device may have an internal system for receiving location data, such as a GPS receiver, or may merely be connectable to a receiver that can receive location data. The navigation series of navigation devices from the present assignee, TomTom N.V., are examples of such navigation devices. These devices enable a user to input a start and destination address. The device then calculates the best route between the two end-points and displays instructions on how to navigate that route. At regular time intervals, the navigation device can compute its position based on received GPS signals, and can display the current position of the vehicle on a map and display (and speak) appropriate navigation instructions (e.g. 'turn left in 100 m'). Graphics depicting the actions to be accomplished (e.g. a left arrow indicating a left turn ahead) can be displayed in a status bar and also be superimposed over the applicable junctions/turnings etc in the roads shown in the map itself. It is known that these navigation devices may also have additional features, such as display of stored images and playback of audio tracks. The navigation functionality as well as the additional features can often be controlled by means of a touch screen. However it is also known to control the navigation device by means of a remote control device. Such a remote control device allows comfortable operation of the navigation device from the car seats, without having to touch the navigation device. The remote control device may provide quick access to some of the functionality of the navigation device. For example, the remote control may provide quick access to functions supporting playback of media files such as audio tracks. The remote control may provide play/pause, next track, and previous track buttons, to provide these functions by activating only one button. Such quick access functions may be available to the user at any time regardless of what is shown on the display. The quick access functions allow control of a secondary functionality without needing to sacrifice any space on the display to controls of the secondary functionality.

The known remote control device transmits signals to the navigation device by means of an RF signal whenever the user presses a key on the remote control device. To receive the commands from the remote control device, the navigation device needs to have proper hardware to receive the RF signals. Consequently, to prepare a navigation device for use of a remote control device, the navigation device needs to be equipped with an RF receiver. Since navigation devices and remote control devices may be sold separately, a lot of RF receivers built into the navigation devices may remain unused, which results in an inefficient use of resources. The RF based remote control device broadcasts signals corresponding to the command buttons activated by the user. These signals are the same for a large population of remote control devices. Any navigation device that receives the signals of a remote control device will execute the commands corresponding to the received signals. This may give rise to problems if the signal is received by more than one navigation device or if the signal is received by another navigation device than intended.

SUMMARY OF THE INVENTION It would be advantageous to have an improved system for controlling a controllable device, in particular a navigation device. To better address this concern, in a first aspect of the invention a system is presented that comprises a controllable device (450) comprising a user input (460), a controller (452) and a wireless communications interface (454); a remote control device (400) for controlling the controllable device and comprising a user input (410), a controller (402) and a wireless communications interface (404); the controller (402) of the remote control device (400) being arranged for: - transmitting a pairing request to the controllable device via the wireless communications interface (404) of the remote control device (400);

- in response to receiving a confirmation from the controllable device via the wireless communications interface (404) of the remote control device (400), pairing with the controllable device to obtain a paired controllable device; and - in response to a user activation of the user input, transmitting an associated command to the paired controllable device via the wireless communications interface (404) of the remote control device (400); and the controller (452) of the controllable device (450) being arranged for:

- receiving the pairing request from the remote control device via the wireless communications interface (454) of the controllable device (450);

- enabling a user to allow or reject the pairing request by means of the user input (460) of the controllable device (450);

- in response to the user allowing the pairing request, transmitting the confirmation to the remote control device via the wireless communications interface (454) of the controllable device (450) and pairing with the remote control device to obtain a paired remote control device; and

- in response to receiving a command from the paired remote control device (400) via the wireless communications interface (454) of the controllable device (450), executing the command.

This system allows a remote control device to pair with and control a particular device, rather than broadcasting the command signal blindly to any devices in the neighborhood. In particular in situations where a plurality of controllable devices is used in a small area, for example in a testing environment or when demonstrating the devices in a retail shop, it is advantageous if only one controllable device responds to the commands issued by the remote control device. Also during regular use, it may happen that two or more controllable devices come within the action radius of the remote control device. In such a case it is inconvenient and while driving a car it may even be dangerous if the controllable device responds to the commands issued by another user's remote control device. This inconvenience is avoided by setting up a pairing between the controllable device and the remote control device, and arranging the controllable device to execute the command received from the paired remote control device.

In an embodiment, the transmitting of the pairing request is performed in response to the user input being activated for a first time.

The system as described allows for a very easy installation procedure: The user may just start using the remote control device by activating the input as if it were a traditional RF based remote control device. The only installation step that may be performed by the user is to allow or reject the pairing request. The system is easy to use and to configure, even though a relatively complex connection protocol, using device pairing, is used. In an embodiment, the enabling the user to allow or reject the pairing request comprises prompting the user to indicate whether the user allows or rejects the pairing request; waiting for a user input indicative of whether the user allows or rejects the pairing request.

This is a efficient way of user interaction. The prompting makes it particularly clear to the user that he or she is expected to provide the input.

In an embodiment, the remote control device is arranged for discovering one or more controllable devices within an action radius of the remote control device, to obtain a list of one or more discovered controllable devices; automatically selecting one of the discovered controllable devices based on a predetermined selection criterion; transmitting the pairing request to the selected controllable device. This makes it easier to deal with the situation in which there is more than one controllable device within the action radius of the remote control device. In an embodiment, the remote control device is arranged for receiving a signal via the wireless communications interface of the remote control device from individual ones of the one or more discovered controllable devices; establishing a strength of the signal received from the individual ones of the one or more discovered controllable devices; and selecting the one of the discovered controllable devices that has a strongest received signal.

Usually, the controllable device that is closest to the remote control device is the one which has to be controlled. This controllable device usually has the greatest received strength. Consequently, this embodiment provides a relatively large probability that the first selected controllable device is the controllable device the user intends to control. In an embodiment, the remote control device is arranged for in response to not receiving the confirmation from the selected controllable device, selecting the one of the discovered controllable devices that has a next strongest received signal.

This efficiently deals with the situation in which the controllable device having the strongest received signal is not the controllable device the user intends to control.

In an embodiment, the remote control device is arranged for - storing a communication identifier of the paired controllable device;

- maintaining a connection with the paired controllable device via the wireless communications interface of the remote control device, wherein the command is transmitted via the connection;

- in response to switching to a power on mode, - if the identifier has been stored, attempting to restore the connection with the paired controllable device using the communication identifier, and

- if the connection with the paired controllable device is not restored, performing the steps of discovering, automatically selecting, and transmitting the pairing request; the paired controllable device being arranged for allowing the paired remote control device to connect. In many cases, the remote control device is always used with the same controllable device. Consequently it is advantageous to store an identifier of the paired controllable device in the remote control device, enabling to restore the connection directly with the paired controllable device without having to select among discovered controllable devices using general selection criteria.

In an embodiment, the remote control device is arranged for giving up the connection when switching to a power off mode, or switching to the power off mode in response to a loss of the connection or in response to receiving a notification from the controllable device that it is shutting down. When in power off mode, no resources may be used for maintaining the connection. On the other hand, if there is no connection, there may not be any reason to remain in power on mode using battery power. When the navigation device is shut down, it is probable that the remote control device will not be used for some time, consequently the remote control switches to the power off mode to save power.

In an embodiment, the remote control device is arranged for switching from the power off mode to the power on mode in response to activation of the user input. It is convenient if the remote control device automatically switches on in response to activation of the user input. No special power on/off switch is required. The user can start using the device without explicitly switching it on, like most other remote control devices. Preferably activation of any button on the remote control device causes the remote control device to switch on.

In an embodiment, the maintaining the connection comprises regularly scheduling time windows for exchanging data packets between the paired controllable device and the paired remote control device; and wherein the system comprises first power saving means for reducing a frequency and/or duration of the time windows after the input means has not been activated during a first predetermined time duration and until the input means is activated. The frequency of the time windows influences the latency of the system as well as the power consumption of the system. After some time of inactivity, the power consumption is reduced, possibly at the cost of an increase of the latency.

An embodiment comprises second power saving means for switching the remote control device to the power off mode, thereby giving up the connection, after the input means has not been activated during a second predetermined time duration. The power off mode is suitable for saving a lot of power. In an embodiment, the wireless communications interface of the remote control device and the wireless communications interface of the controllable device are Bluetooth communications interfaces, wherein the remote control device and the controllable device are arranged for exchanging the pairing request, the confirmation message, and the command message via the Bluetooth communications interfaces. The Bluetooth protocol is suitable for this kind of system, for example because of its low power consumption, low cost hardware, and multi-purpose functionality. For example, in the controllable device, the Bluetooth communications interface may be used to communicate with a mobile phone, a media player, or car audio equipment. In an embodiment, the remote control device acts as a master device and the controllable device acts as a slave device. This is a convenient way of setting up the connection, as the connection may be initiated by the remote control device rather than by the controllable device.

In an embodiment, the first power saving means is arranged for putting the connection in a sniff mode, a hold mode, or a park mode when reducing the frequency of data packets. These are Bluetooth compatible and power saving modes which are relatively easy to implement.

An embodiment comprises a remote control device comprising a user input, a controller, and a wireless communications interface; the remote control device being arranged for: - transmitting a pairing request to the controllable device;

- in response to receiving a confirmation from the controllable device, pairing with the controllable device to obtain a paired controllable device; and

- in response to a user activation of the user input, transmitting a command to the paired controllable device.

(copy remaining claims)

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be further elucidated and described with reference to the drawing, in which Figure 1 shows a flowchart illustrating processing steps of an embodiment; Figure 2 shows a flowchart illustrating processing steps of an embodiment; Figure 3A shows a remote control device; Figure 3B shows a diagram of a remote control device; and Figure 4 illustrates an embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

The detailed description of embodiments focuses on the concept of a navigation device that is controlled by a remote control device. However, it will be understood that instead of a navigation device, any other kind of device may be controlled by the remote control device. For example, a television set may also be controlled by the described remote control device. For example also devices that are used in a car, such as car audio equipment, mobile phones, and mobile mp3 players, may all act as controllable devices instead of a navigation device. Whenever a text message is displayed on a display, the text message may also be reproduced by means of a spoken message. For example, the spoken message may be an audio recording or it may be generated by means of text-to-speech recognition.

The conventional remote control device of a navigation device uses RF signals to convey a signal whenever a key is depressed on the remote control device. As RF signals are only used for the remote control device, and is not used for other purposes in the navigation device, the RF receiver in the navigation device is solely used for receiving the remote control commands. Because navigation devices and remote control devices are sold separately, and not all users of a navigation device purchase a remote control device, many navigation devices will never be controlled by the remote control device, and the RF receiver will never be used. This makes the RF protocol rather expensive relative to the number of remote control devices in actual use.

Bluetooth is a communications protocol that may be used for a number of purposes in the navigation device. Bluetooth is used to connect the navigation device to a mobile phone, where the mobile phone may be used as a modem device to connect to a service database to retrieve traffic information and/or map updates. Reversely, the navigation device may serve as a Bluetooth hands free set for a mobile phone to enable the user to make telephone calls safely while driving.

The Bluetooth hardware, which may be present in the navigation device, may also be used to receive remote control commands from a remote control device. To this end, the remote control device (RC) may also be provided with an appropriate Bluetooth hardware part. In this case, the RF hardware is not needed any more, neither in the navigation device nor in the remote control device. The navigation device may be produced more cost effectively, because the RF hardware element is omitted and its functionality is taken over by the Bluetooth hardware element which was already present on the device.

One drawback of a remote control device is that it transmits its commands in a broadcast fashion, i.e., as a general signal not directed to any particular device. Consequently, all the navigation devices within an action radius of the remote control would respond to the commands issued by the remote control device. This may be inconvenient in situations where a plurality of navigation devices are in use close to each other, for example when two cars with navigation equipment are waiting at a traffic light next to each other, or when cars are close to each other in a traffic jam.

This drawback may be overcome by setting up a point-to-point (i.e., addressed) connection between the remote control device and the navigation device. This way, the commands are only transmitted to the connected navigation device, without disturbing any other navigation devices within the action radius of the remote control device. The use of such a remote control device and ways to select the navigation device to connect to, are described by the following exemplary use cases.

Use case A: The remote control device power is turned on for the first time while the navigation device power is on. This use case applies for example when the user has bought a new remote control device and takes it into use for the first time. The user's navigation device is on and he activates the remote control device. In response to the user activation, the remote control device automatically starts the Bluetooth pairing process and sends a message to the navigation device. The navigation device displays a prompt on its display and enables the user to allow or reject the remote control device to connect. After the user has accepted the connection, the remote control device can be used to control the navigation device. To this end, a connection is set up between the remote control device and the navigation device, and the remote control device sends control messages in response to buttons on the remote control device being activated by the user.

Use case B: The remote control device power is turned on, while Bluetooth pairing exists already and the navigation device power is on. The user activates remote control device and Bluetooth pairing has been done sometimes earlier. In this case, the remote control device connects automatically to the navigation device and the navigation device automatically accepts the connection. The navigation device only displays a flash message and/or produces a voice message, which may be generated by text-to-speech conversion, to inform the user that the remote control device is recognized. The user can control the navigation device with remote control device because the remote control device sends control messages in response to buttons on the remote control device being activated by the user.

Use case C: The remote control device power is turned on for the first time while the navigation device power is off. For example, the user has purchased a new remote control device and takes it into use. However, the user's navigation device power is off while he activates the remote control device. In this case, the remote control device starts the Bluetooth pairing process, but it cannot find any navigation device. Subsequently, the remote control device will power off automatically. Use case D: The user purchases a new navigation device and wants to control it with his remote control device. The user has used the remote control device with the old navigation device before. He purchases a new navigation device and wants to control it with the remote control device. He turns on the power of his new navigation device and after that activates the remote control device. The remote control device cannot connect to the old navigation device it was paired to. Therefore, it will start to search for any other appropriate (controllable) Bluetooth devices. The remote control device will find the new navigation device, request to connect with it, and the navigation device will prompt the user to accept the connection. If the user accepts the new connection, the old Bluetooth pairing information (which identified the old navigation device) is replaced with the new Bluetooth pairing information (which identifies the new navigation device). Subsequent commands are transmitted only to the new navigation device and not to the old navigation device.

Use case E: Several navigation devices available. The user either takes remote control device into use for the first time or activates it without having the paired navigation device in the neighborhood or with the paired navigation device in power off mode. In such a case, if there are several navigation devices around, the remote control device will check which navigation device has the strongest Bluetooth signal, and will attempt to do Bluetooth pairing with it. The navigation device with which the remote control device attempts to pair with prompts the user to confirm or reject the connection. If confirmed, the remote control device pairs with this navigation device and replaces the existing pairing information, if available.

In normal use, the remote control device and the navigation device are paired by means of Bluetooth pairing, allowing the remote control device to be used for controlling the navigation device. When the user activates the remote control device by pressing any button, the navigation device connects to the paired navigation device, and the navigation device responds by shortly displaying the flash message "Remote control connected". The user cannot turn off the remote control device. It goes into a sleep mode after for example 20 seconds of inactivity time. The remote control device power is turned off automatically if the Bluetooth connection disappears, if the user turns off the power of the navigation device, or if the remote control device is not used for more than e.g. one hour.

When the remote control device is new and unused, it does not yet have a Bluetooth pairing. When the user activates the remote control device for the first time, the remote control device attempts to pair with a navigation device that has the strongest Bluetooth signal. This is because the navigation device having the strongest Bluetooth signal is usually the navigation device closest to the remote control device, and usually the user wishes to control the navigation device that is closest to the remote control device (for example the remote control device and the navigation device are in the same car). Also, the remote control only attempts to connect with a device it is configured to be able to control. For example, the remote control device may be configured to only be able to control navigation devices of a particular brand and/or type. The devices that the remote control device is configured to be able to control may be referred to as "compatible devices". Such devices may be recognized, for example by looking for a specific device class range. The navigation device may be arranged for refusing to connect to a new remote control device while driving. In such a case, if the user is driving and a new remote control device attempts to pair with the navigation device, the navigation device shows a flash message with the text "New remote control can not be connected while driving". However, if the user is stationary, the navigation device prompts the user to accept connection by displaying the message "New remote control is trying to connect to this device. Do you want to accept the connection?". If the user confirms, the pairing is done and the user can start to control the navigation device using the remote control device.

If the remote control device cannot find any compatible device during the Bluetooth device search, the remote control device will shut down automatically. If the Bluetooth connection with the navigation device having the strongest Bluetooth signal does not succeed, the remote control device will try to connect with the navigation device having the next strongest Bluetooth signal. If the user does not accept the prompt in the navigation device, remote control device will try to connect to the navigation device with the next strongest Bluetooth signal. If the user does not select any answer to the prompt "New remote control is trying to connect to this device. Do you want to accept the connection?" in the navigation device within, for example, 30 seconds, the navigation device selects automatically the "No" option and the remote control device starts to connect with the navigation device having the next strongest Bluetooth signal. If the remote control device has pairing to the navigation device but the paired navigation device is not available, the remote control device will search for other navigation devices. If the remote control device finds another navigation device, it will try to do Bluetooth pairing with that one. If the pairing is successful, the existing Bluetooth pairing is replaced with the new one. If the new pairing is not successful, the old Bluetooth pairing remains valid.

In the following, a number of exemplary embodiments will be discussed. In relation to figures 1 , 2, and 3, some embodiments will be described in detail. Many features described therein are optional. In relation to figure 4, a more general embodiment will be described. However, the skilled person will appreciate that many variations are possible without departing from the scope of the claims.

Figure 1 illustrates a flowchart of a connecting and pairing process between a remote control device and a navigation device. Assuming the remote control is in the power off mode, it will wake up at 102 in response to the user pressing any key. In step 104 the remote control device will check whether a pairing with a navigation device already exists. If yes, in step 106 the remote control device will attempt to connect with the paired navigation device. In step 108 it is verified whether the attempt is successful. If yes, in step 138 a flash message is displayed on the navigation device indicating "Remote control connected", and in step 110 the remote control device remains in power on mode waiting for new user commands. If the result in step 104 or step 108 is no, in step 112 the remote control device will search for any available and controllable devices, i.e., any compatible devices, in particular navigation devices. In step 114 it is verified whether any compatible devices were found. If no, in step 136 the remote control device keeps the old pairing if there was one, and in step 150 the remote control device shuts down itself, i.e., switches the power of the remote control device off. If any compatible devices were found in step 114, in step 116 it is verified whether more than one compatible device was found. If yes, in step 118 the compatible device having the strongest communication signal is selected. Otherwise the one found device is selected. Subsequently in step 120, an attempt is made to connect to the selected device. In step 124 it is verified whether the connection attempt was successful. If not, in step 126 it is verified whether one or more compatible devices for which a connection attempt has not yet been made are available in the list of compatible devices. If not, the flow continues at step 136. If yes, in step 122 the compatible device with the next strongest signal is selected and the flow continues at step 120. If in step 124 the connection was successful, it is verified in step 128 whether the user is driving. This is detected by determining whether the navigation device is moving or whether it is stationary. For example, a threshold on the velocity of the navigation device is used. If the compatible device is not a navigation device and/or does not have positioning capability, the step 128 is skipped. If in step 128 it is detected that the user is driving, in step 130 the navigation device displays a flash message "New remote control cannot be connected while driving", and the navigation device sends a message to the remote control device indicating it refuses the connection, and the flow continues at step 126. If in step 128 it is detected that the user is not driving, in step 132 a prompt "New remote control is trying to connect to this device. Do you want to accept the connection?" is displayed on the navigation device, and the navigation device allows the user to input either yes or no. Instead of or in addition to the display of the prompt, the navigation device may generate a similar spoken prompt. This spoken prompt may be generated by means of text-to-speech conversion. The spoken prompt (and/or the displayed prompt) may indicate to the user that he or she should touch a certain area of the display (labeled "yes") to accept the connection, or another area (labeled "no") to refuse the connection. It is also possible to only provide a "yes" touch button, in which case a user who does not wish to allow the connection should only refrain from touching the "yes" button, until the time-out occurs. In step 134, it is verified whether the user has selected yes or no and whether a time-out has occurred without a response from the user. If the user has selected no or if a time-out has occurred without a response from the user, the flow continues at step 126. If the user has selected yes in step 134, the flow continues at step 138.

Figure 2 illustrates an embodiment of a power management control flow. In step 202, the remote control device has just connected to the navigation device (compare to step 110 of figure 1 ), and in step 204 a flash message "Remote control connected" is displayed on the navigation device. In step 206, the remote control device is in active mode and the connection is kept alive using regular data packets and/or a high frequency of listen windows during which the navigation device listens to any messages transmitted by the remote control device. The remote control device responds to any input from the user by transmitting a corresponding control command to the navigation device. The latency is short because of the high frequency of listen windows (e.g. 150 milliseconds between two consecutive listen windows during which the remote control device may transmit a command). In step 208 it is checked whether the remote control device has not been used for a predetermined time duration. For example, it is checked whether the remote control device has not been used for 20 seconds or more. If this is the case, in step 214 the remote control device switches to a sleep mode, in which fewer data packets are used to keep the connection alive and/or a lower frequency of listen windows is employed. For example, a Bluetooth sniff mode is used. While in sleep mode, the frequency of the sniffs may decrease in several phases. In step 220 it is detected that a key has been activated on the remote control device, causing the remote control device to return to the active mode, and the flow continues at step 206. In step 216, it is detected that the remote control device has not been used for a second predetermined time duration. For example, it is detected that the remote control device has not been used for at least one hour. In this case in step 218 the navigation device displays a flash message "Remote control disconnected", and in step 150 the remote control device switches the power off. When the user activates any button on the remote control device, the flow continues at step 102.

In step 210, it is detected that the Bluetooth connection has disappeared. For example, the navigation device is moved out of the action radius of the remote control device. In this case, the flow continues at step 218. In step 212, it is detected that the navigation device is being turned off. In this case, the flow continues at step 150. The above scenario has been described mainly in the context of a remote control device controlling a navigation device. However, the concepts described in this text could also be applied to other kinds of devices instead of navigation devices, for example media players, car stereo equipment, mobile phones, all could be controlled by the remote control device. In case of a multi-purpose or universal remote control device, separate pairings could be made in each category of controllable devices. For example, the remote control device could be paired with one navigation device, one car stereo device, and one mobile phone at the same time. The buttons activated on the remote control device would determine to which of the paired devices each commands is transmitted. Figure 3A illustrates an example of a Bluetooth remote control device for use with a navigation device. The same Bluetooth remote control device is shown diagrammatically in figure 3B. The figure shows an indicator led 302; a 4-way navigation button 304 for navigating up, down, left, and right; a selection button 306; a bottom left button 314 for performing the menu action displayed on the bottom left on the display of the navigation device; a bottom right button 308 for performing the menu action displayed on the bottom right on the display of the navigation device; a bottom center button 310 for performing various functions including start/stop of playback of audio files stored on the navigation device; and a volume up/down control button pair 312. When any of the buttons is depressed, the remote control awakens from the sleep mode or the remote control switches on the power if the power was off. If the remote control is in the active mode or has awakened from the sleep mode, a command message corresponding to the activated button is transmitted to the connected navigation device. If the remote control was in power off mode, the activation of the button is just used to trigger power on and to set up the connection with the navigation device. The actual command message is not transmitted to the navigation device, because of an initial delay which may be occur before the connection has been established. It would be inconvenient if the navigation device would perform the action after such a delay, hence it is preferred to refrain from sending the command that caused the power on. In an alternative embodiment the command message is transferred as soon as the connection has been established. The indicator led 302 is used to indicate whether the remote control device is in active mode, whether it is waking up from sleep mode, and whether it is waking up from power off mode. Preferably, in active mode the led 302 lights up continuously. When waking up from sleep mode, the led 302 blinks until it has transmitted the command message. After a switch from power off to power on, the led 302 blinks more slowly than when waking up from sleep mode and until the remote control device has connected with a navigation device. During sleep mode and during power off mode, the led is off. The use of the led 302 is useful for communicating to the user the fact that there may be a delay between activation of the button and actual performance of the command by the navigation device, in particular after a power on switch and to a lesser extend when waking up from the sleep mode.

It is preferred that the remote control device is the master device in a Bluetooth connection with a navigation device, because the remote control device initiates the communication and has full control over the power saving facilities. In sleep mode, instead of sniff mode, another type of low-power consuming connection mode may be selected, such as hold mode or park mode. These modes are known from the Bluetooth Specification. In alternative embodiments, other wireless communications protocols may be used including Wifi and IrDA.

Figure 4 illustrates a diagram of a system comprising a remote control device 400 and a navigation device 450. Navigation device 450 may comprise a controller (e.g. a CPU) 452, a wireless communications interface 454 with antenna 458, a touch screen 460, a GPS receiver 462, and a storage means 456. Remote control device 400 may comprise a controller 402, a wireless communications interface 404 connected to an antenna 408, a user input 410 comprising one or more buttons 304-314, and a storage means 406. The wireless communications interfaces 404 and 454 may be capable of communicating with each other via the antennas 408 and 456 and through a wireless communications medium 412. The controller 402 of the remote control device 400 may be programmed by means of firmware. The controller, controlled by the program in the firmware, may be arranged to control the wireless interface 404. In operation, the remote control device may be arranged for transmitting a pairing request to the navigation device. This pairing request may take any form. A connect request coming from the remote control device may function as a pairing request. Alternatively, first a connection may be set up between the remote control device and the navigation device, and subsequently the pairing request may be transmitted via the connection.

In an embodiment, the navigation device 450 receives the pairing request from the remote control device. It may enable a user to allow or reject the pairing request, for example by displaying a prompt message and two touch buttons, one touch button representing an allowance and one touch button representing a rejection. If the user does not make a choice within a predetermined time duration, the connection may be rejected and the prompt message and touch buttons may be removed from the display. In response to the user allowing the pairing request, e.g. by pressing the 'allowance' touch button, the navigation device transmits a confirmation to the remote control device and pairs with the remote control device to obtain a paired remote control device. Preferably an identifier of the paired remote control device is stored in non-volatile memory (e.g. flash memory) 456 for future reference.

In response to receiving a confirmation from the navigation device, the remote control device 400 may pair with the navigation device 450 to obtain a paired navigation device. Preferably an identifier of the paired navigation device is stored in a non-volatile memory (e.g. a flash memory) 406 for future reference.

When the user activates the input 410, e.g. a button on the remote control device, the remote control device may transmit a command corresponding to that button to the paired navigation device 450. In response to receiving such a command from the paired remote control device, the navigation device may execute the command.

In an embodiment, the remote control device uses a discovery mechanism, for example the device discovery protocol provided by Bluetooth, to discover one or more navigation devices within an action radius of the remote control device, to obtain a list of one or more discovered navigation devices. The action radius here means close enough to the remote control to enable communication between the remote control device and the navigation device. The remote control device may automatically select at least one of the discovered navigation devices based on predetermined selection criteria. For example the navigation device having the strongest signal is selected, or a navigation device of a particular brand and/or type is preferred over other brands or types, or a navigation device that is not yet paired to a remote control device is preferred over a navigation device that is already paired to another remote control device. The remote control device transmits the pairing request to the selected navigation device. In an embodiment, in response to receiving a rejection or after a time-out during which no response is received, the next navigation device is selected according to the selection criteria, for example the one of the discovered navigation devices that has the next strongest received signal is selected.

In an embodiment, the remote control device stores an identifier of the paired navigation device in storage means 406. It maintains an active connection with the paired navigation device, and this active connection is used to transmit the commands. The active connection may be given up when switching to a power off mode. Also, the power may be switched off in response to a loss of the connection or if the navigation device notifies the remote control device that it is shutting down.

In an embodiment, the remote control switches to power on mode in response to activation of the user input, for example if any command key 304-314 is activated by depressing the key. In response to switching to a power on mode, the remote control device may attempt to connect to a navigation device to convey the command corresponding to the key. If an identifier of a paired navigation device is stored in the storage means 406, an attempt may be made to restore the connection with the paired navigation device. The presence of the paired navigation device may be checked by comparing an identifier received from a navigation device to the stored identifier. The paired navigation device may have the identifier of the paired remote control device stored in its storage means 456, and if the paired remote control device attempts to connect, the paired navigation device allows the connection, without requiring any user interaction.

In an embodiment, if the connection with the paired navigation device is not restored, for example because the paired navigation device is not within the action radius of the remote control device, the latter selects another navigation device in the list of discovered navigation devices and attempts to pair with the selected navigation device as described above.

When using the Bluetooth protocol, like many other wireless communications protocols, maintaining the connection may comprise regularly scheduling time windows for exchanging data packets between the paired navigation device and the paired remote control device. This helps to keep the devices synchronized. For example, the system comprises first power saving means for reducing a frequency and/or duration of the time windows after the input means has not been activated during a first predetermined time duration and until the input means is activated. This saves power. Normally after around 20 seconds the first power saving means is activated. The master device usually determines when the sleep mode is activated, so the first power saving means may be comprised in the master device. In an embodiment, the first power saving means is arranged for putting the connection in a sniff mode, a hold mode, or a park mode when reducing the frequency of data packets.

In an embodiment, the system further comprises second power saving means for switching the remote control device to the power off mode, thereby giving up the connection, after the input means has not been activated during a second predetermined time duration and for. For example, after around one hour of inactivity, the remote control switches its power off.

In response to activation of the user input while the remote control is in power off mode, the remote control device may be switched back to the power on mode.

The connection may be a Bluetooth connection. Preferably, the remote control device and the navigation device are arranged for exchanging the pairing request, the confirmation message, and the command message via the Bluetooth connection. Preferably, the remote control device acts as a master device and the navigation device acts as a slave device.

A method of controlling a navigation device may comprise, in a remote control device, transmitting a pairing request to the navigation device, in response to receiving a confirmation from the navigation device, pairing with the navigation device to obtain a paired navigation device, and in response to a user activation of the user input, transmitting a command to the paired navigation device. The method may further comprise, in the navigation device, receiving the pairing request from the remote control device, enabling a user to allow or reject the pairing request, in response to the user allowing the pairing request, transmitting the confirmation to the remote control device and pairing with the remote control device to obtain a paired remote control device, and in response to receiving the command from the paired remote control device, executing the command.

It will be appreciated that the invention also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into practice. The program may be in the form of source code, object code, a code intermediate source and object code such as partially compiled form, or in any other form suitable for use in the implementation of the method according to the invention. It will also be appreciated that such a program may have many different architectural designs. For example, a program code implementing the functionality of the method or system according to the invention may be subdivided into one or more subroutines. Many different ways to distribute the functionality among these subroutines will be apparent to the skilled person. The subroutines may be stored together in one executable file to form a self- contained program. Such an executable file may comprise computer executable instructions, for example processor instructions and/or interpreter instructions (e.g. Java interpreter instructions). Alternatively, one or more or all of the subroutines may be stored in at least one external library file and linked with a main program either statically or dynamically, e.g. at run-time. The main program contains at least one call to at least one of the subroutines. Also, the subroutines may comprise function calls to each other. An embodiment relating to a computer program product comprises computer executable instructions corresponding to each of the processing steps of at least one of the methods set forth. These instructions may be subdivided into subroutines and/or be stored in one or more files that may be linked statically or dynamically. Another embodiment relating to a computer program product comprises computer executable instructions corresponding to each of the means of at least one of the systems and/or products set forth. These instructions may be subdivided into subroutines and/or be stored in one or more files that may be linked statically or dynamically.

The carrier of a computer program may be any entity or device capable of carrying the program. For example, the carrier may include a storage medium, such as a ROM, for example a CD ROM or a semiconductor ROM, or a magnetic recording medium, for example a floppy disc or hard disk. Further the carrier may be a transmissible carrier such as an electrical or optical signal, which may be conveyed via electrical or optical cable or by radio or other means. When the program is embodied in such a signal, the carrier may be constituted by such cable or other device or means. Alternatively, the carrier may be an integrated circuit in which the program is embedded, the integrated circuit being adapted for performing, or for use in the performance of, the relevant method.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A system for controlling a controllable device, in particular a navigation device, the system comprising a controllable device (450) comprising a user input (460), a controller (452) and a wireless communications interface (454); a remote control device (400) for controlling the controllable device and comprising a user input (410), a controller (402) and a wireless communications interface (404); the controller (402) of the remote control device (400) being arranged for:

- transmitting a pairing request to the controllable device via the wireless communications interface (404) of the remote control device (400);

- in response to receiving a confirmation from the controllable device via the wireless communications interface (404) of the remote control device (400), pairing with the controllable device to obtain a paired controllable device; and

- in response to a user activation of the user input, transmitting an associated command to the paired controllable device via the wireless communications interface (404) of the remote control device (400); and the controller (452) of the controllable device (450) being arranged for: - receiving the pairing request from the remote control device via the wireless communications interface (454) of the controllable device (450);

2. The system according to claim 1 , wherein the transmitting of the pairing request is performed in response to the user input being activated for a first time.

3. The system according to claim 1 , wherein the enabling the user to allow or reject the pairing request comprises prompting the user to indicate whether the user allows or rejects the pairing request; waiting for a user input indicative of whether the user allows or rejects the pairing request.

4. The system according to claim 1 , wherein the remote control device is arranged for discovering one or more controllable devices within an action radius of the remote control device, to obtain a list of one or more discovered controllable devices; automatically selecting one of the discovered controllable devices based on a predetermined selection criterion; transmitting the pairing request to the selected controllable device.

5. The system according to claim 4, wherein the remote control device is arranged for receiving a signal via the wireless communications interface of the remote control device from individual ones of the one or more discovered controllable devices; establishing a strength of the signal received from the individual ones of the one or more discovered controllable devices; and selecting the one of the discovered controllable devices that has a strongest received signal.

6. The system according to claim 5, wherein the remote control device is arranged for in response to not receiving the confirmation from the selected controllable device, selecting the one of the discovered controllable devices that has a next strongest received signal.

7. The system according to claim 4, 5, or 6, wherein the remote control device is arranged for

- storing a communication identifier of the paired controllable device;

- in response to switching to a power on mode,

- if the identifier has been stored, attempting to restore the connection with the paired controllable device using the communication identifier, and - if the connection with the paired controllable device is not restored, performing the steps of discovering, automatically selecting, and transmitting the pairing request; the paired controllable device being arranged for allowing the paired remote control device to connect.

8. The system according to claim 7, wherein the remote control device is arranged for giving up the connection when switching to a power off mode, or switching to the power off mode in response to a loss of the connection or in response to receiving a notification from the controllable device that it is shutting down.

9. The system according to claim 7, wherein the remote control device is arranged for switching from the power off mode to the power on mode in response to activation of the user input.

10. The system according to claim 7 or 9, wherein the maintaining the connection comprises regularly scheduling time windows for exchanging data packets between the paired controllable device and the paired remote control device; and wherein the system comprises first power saving means for reducing a frequency and/or duration of the time windows after the input means has not been activated during a first predetermined time duration and until the input means is activated.

1 1 . The system according to claim 7, 9, or 10, further comprising second power saving means for switching the remote control device to the power off mode, thereby giving up the connection, after the input means has not been activated during a second predetermined time duration.

12. The system according to any of claims 7 to 11 , wherein the wireless communications interface of the remote control device and the wireless communications interface of the controllable device are Bluetooth communications interfaces, and wherein the remote control device and the controllable device are arranged for exchanging the pairing request, the confirmation message, and the command message via the Bluetooth communications interfaces.

13. The system according to claim 12, wherein the remote control device acts as a master device and the controllable device acts as a slave device.

14. The system according to claim 12 in dependence on claim 10, wherein the first power saving means is arranged for putting the connection in a sniff mode, a hold mode, or a park mode when reducing the frequency of data packets.

15. A remote control device (400) for use in the system according to claim 1 , comprising a user input (410), a controller (402) and a wireless communications interface (404); the controller (402) of the remote control device (400) being arranged for:

- transmitting a pairing request to a controllable device via the wireless communications interface (404) of the remote control device (400); - in response to receiving a confirmation from the controllable device via the wireless communications interface (404) of the remote control device (400), pairing with the controllable device to obtain a paired controllable device; and

- in response to a user activation of the user input, transmitting an associated command to the paired controllable device via the wireless communications interface (404) of the remote control device (400).

16. A controllable device (450), in particular a navigation device, for use in the system according to claim 1 , comprising a user input (460), a controller (452) and a wireless communications interface (454); the controller (452) of the controllable device (450) being arranged for: - receiving a pairing request from a remote control device (400) via the wireless communications interface (454) of the controllable device (450);

- in response to the user allowing the pairing request, transmitting a confirmation to the remote control device via the wireless communications interface (454) of the controllable device (450) and pairing with the remote control device to obtain a paired remote control device; and

17. A method of controlling a controllable device, in particular a navigation device, the method comprising wirelessly transmitting a pairing request to the controllable device; in response to receiving a confirmation from the controllable device, pairing with the controllable device to obtain a paired controllable device; and in response to a user activation of a user input, wirelessly transmitting an associated command to the paired controllable device.

18. A method of controlling a controllable device, in particular a navigation device, the method comprising wirelessly receiving a pairing request from a remote control device; enabling a user to allow or reject the pairing request; in response to the user allowing the pairing request, wirelessly transmitting a confirmation to the remote control device and pairing with the remote control device to obtain a paired remote control device; and in response to receiving a command from the paired remote control device (400) via the wireless communications interface (454) of the controllable device (450), executing the command.

19. A computer program product comprising instructions for causing a processor to perform the method according to claim 17 or 18.