GB2461097A

GB2461097A - Power conservation mode for allowing an emergency phone call in a mobile phone.

Info

Publication number: GB2461097A
Application number: GB0811409A
Authority: GB
Inventors: Petr Smrz
Original assignee: Nokia Oyj; Symbian Software Ltd
Current assignee: Nokia Oyj
Priority date: 2008-06-20
Filing date: 2008-06-20
Publication date: 2009-12-23
Also published as: GB0811409D0

Abstract

A computer device such as mobile phone device has two modes of operation, a normal power mode when available power from a power source is above a predetermined threshold and an emergency mode when the power available is below the threshold. The emergency mode allows an emergency call to be made which may be assigned to a predefined emergency call key. The power source is preferably a depleteable power source such as an electrochemical cell such as a battery. In a futher mode of operation the device is switched off when the power falls below the threshold. The device may also be turned off using a timer which is initiated when the power level falls below the threshold. The device may also comprise an external indicator which is either visual or audible when the device is in an emergency mode. In a second embodiment a second power source may be provided which is activated when the first power source falls below the threshold. Power is then drawn form the second source while in the emergency mode.

Description

I

A computing device and method of operation of a computing device The present invention relates to a computing device which is arranged to operate in an emergency mode when the power available in the device falls below a predefined threshold. The present invention also relates to a computing device which includes two electrochemical cells, the device being arranged to operate in different modes, depending upon which cell power is being drawn from. The present invention also relates to methods of operating the aforementioned devices.

Backqround to the Invention The primary purpose of a mobile phone is to enable a user to make telephone calls. One type of call which may be made is an emergency call to the emergency services in the event of a crime, injury or fire. One of the main problems with mobile phones is that they have limited battery life. Users can find themselves in a situation where they are unable to make an emergency call because their phone battery has run flat. It is up to a user to manage the battery life of their phone. Typically users do not do this, and hence they find themselves in a situation in which no calls can be made.

UK Patent Application Publication No. GB2433612A in the name of Symbian Software Limited discloses a mobile phone which limits the functions available based on remaining battery life. The phone utilises a tiered system of thresholds. The number of functions available is steadily reduced as the battery capacity reduces below 50%, 40%, 30%, 20% and 10% respectively.

However, the phone does not deal with the problem of making emergency calls. Even when the available battery power is below 10%, full call and messaging functionality is available to a user. To some users, this amounts to normal usage. This would enable a user to run the battery down by making non-emergency calls.

The device disclosed in GB2433612A does not necessarily reduce battery consumption for an average user. Even below 10% of full power, the phone is still drawing power when idle in the same manner as it would with 90% of full power. Furthermore, although the device disclosed in GB2433612A does operate in different modes, the device draws power from the same power source in all modes. When the battery is flat, the device may no longer be used as there is no back-up power source.

Summary of the Invention

The present invention provides a computing device having at least one power source; wherein the device is arranged to operate in a normal mode while the amount of power available in said at least one power source is above a predefined threshold; and the device is further arranged to operate in an emergency mode, when the amount of power available in said at least one power source is below said predefined threshold.

The present invention also provides a method of operating a computing device, wherein the device includes at least one power source, the method comprising: operating the device in a normal mode while the amount of power available in said at least one power source is above a predefined threshold; and operating the device in an emergency mode, when the amount of power available in said at least one power source is beloW said predefined threshold.

The present invention further provides a computing device having a first electrochemical cell and a second electrochemical cell; wherein the device is arranged to operate in a first mode while the power available in the first electrochemical cell is above a predefined level, and, in said first mode, the device uses said first electrochemical cell for power; and the device is further arranged to operate in a second mode, when power available in the first electrochemical cell drops to said predefined level, and, in said second mode, the device uses said second electrochemical cell for power.

The present invention further provides a method of operating a computing device, wherein the device includes a first electrochemical cell and a second electrochemical cell; the method comprising: operating the device in a first mode, while the power available in the first electrochemical cell is above a predefined level, and, in said first mode, using said first electrochemical cell for power; and operating the device in a second mode, when power available in the first electrochemical cell drops to said predefined level, and, in said second mode, using said second electrochemical cell for power.

Other features of the present invention are defined in the appended claims.

Features and advantages associated with the present invention will be apparent from the following description of the preferred embodiments.

Brief Description of the Drawings

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a mobile device in accordance with an embodiment of the invention; Figure 2 is a schematic diagram showing the components of the mobile device of Figure 1; Figure 3 shows the mobile device of Figure 1 in a first mode of operation; Figure 4 shows the mobile device of Figure 1 in a second mode of operation; Figure 5 is a flow chart showing the operation of the device of Figure 1; Figure 6 shows a mobile device in accordance with a further embodiment of the invention; Figure 7 is a schematic diagram showing the components of the mobile device of Figure 6; Figure 8 shows the mobile device of Figure 6 in a first mode of operation; Figure 9 shows the mobile device of Figure 6 in a second mode of operation; Figure 10 is a flow chart showing the operation of the device of Figure 6;

Detailed Description of the Embodiments

Referring to Figure 1, a mobile device 100 comprises an outer casing 101, which includes an earphone 102 and a microphone 103. The mobile device 100 also includes a keypad 104 and a display 105. The keypad 104 enables a user to enter information into the mobile device 100 and instruct the mobile device to perform the various functions which it provides. For example, a user may enter a telephone number, or select another mobile device from a list stored on the mobile device 100, as well as perform functions such as initiating a telephone call.

Figure 2 is a schematic diagram showing the components of the mobile device 100. The device includes a system bus 106 to which the components are connected and which allows the components to communicate with each other.

Here, the components are shown to communicate via a single system bus 106, however in practice the mobile device may include several buses to connect the various components. The components of the mobile device 100 include a processor unit 107, memory 108, an earphone controller 109, a microphone controller 110, a display controller 111, a keyboard controller 112, a transceiver 113 and a storage device controller 114. Figure 4 shows a single processor unit 107, however in practice the device may include two or more processor units to control different components of the device. In particular, the device 100 may include a baseband processor unit to control a telephony stack, and an application processor to control an operating system and a user interface of the device. The transceiver 113 is also connected to an antenna 115. The mobile device 100 is arranged to communicate, using transceiver 113, with a base station of a mobile phone network (not shown).

The storage device controller 114 is connected to a storage device 116 which may be an internal hard drive or a removable storage device such as a flash memory card.

In a first embodiment, the mobile device 100 includes an electrochemical cell 117, commonly referred to as a battery. The cell 117 provides power to all the phone systems via power wires (not shown). The cell 117 is connected to a power sensor 118, which is in turn connected to the bus 106. The power sensor 118 provides an indication of the amount of power remaining in cell 117.

The mobile device has an operating system (not shown) and a user interface (not shown) stored in a read only memory (ROM) portion of memory 108. The operating system controls all the functions of the mobile device 100. In particular it enables a user to initiate a phone call using the keypad 104. The operation of the operating system is familiar to the person skilled in the art and will not be described here in any detail.

Figure 3 shows the mobile device 100 operating in normal mode. The power sensor 118 provides the operating system with an indication of the amount of power remaining in the cell 117. This information is then displayed on display 105. A cell power indicator 119 indicates the power remaining in cell 117 as a percentage of the cell's power capacity. The mobile device 100 also displays the mode that the device is currently operating in via operating mode indicator 120. In the present case, the cell 117 is at 55% of capacity and the device is operating in normal mode, as indicated by operating mode indicator 120.

When the power remaining in cell 117 drops below 10%, the device 100 switches to emergency mode. As can been seen in Figure 4, the cell power indicator 119 shows that the cell 117 is at 8% of capacity. The operating mode indicator 120 indicates that the device is running in emergency mode.

In emergency mode the functions available to a user are a drastically reduced.

In this embodiment, the only function available to user is the ability to call the emergency services. This is achieved by pressing a hot key, which may be any key on the keypad 104. The hot key may be pre-designated by the handset provider or designated by the user. In emergency mode all other keys are disabled. A user initiates an emergency call be pressing and holding the hot key for a short time period, for example for one second.

In addition to monitoring the power remaining in the cell 117, the device 100 also monitors for the presence of a connected charger (not shown). When a charger is connected to the mobile device 100, and the charger is switched on, the device does not enter emergency mode, or if the device 100 is in emergency mode, it returns to normal mode.

The advantage of monitoring for a charger is that, when charging, battery power is not being reduced and a user should therefore be able to access all phone functions.

Figure 5 is a flow chart showing the mechanism by which the device 100 operates in accordance with this embodiment. Assuming the cell 117 is at least at 10% of capacity, the operating system will be monitoring the available power using the power sensor 118 (step 200). If the operating system detects that more than 10% of the cell's power remains, it will maintain the device in normal mode (step 201). At this step, the operating system displays the available power and the fact that the device is operating in normal mode. The operating system then repeats steps 200 and 201. Although the power sensor 118 actually takes power readings discretely, the interval between readings is so short that steps 200 and 201 effectively occur continuously.

If, at step 200, the power sensor 118 indicates that the power available has reduced below 10%, the operating system checks to see whether or not the cell is currently being charged (step 202). If the mobile device 100 is being charged, the operating system maintains the device in normal mode and returns to step 200. When the cell power first drops below 10% it is highly unlikely that a charger will be connected, otherwise the cell power would not have dropped below 10%. However, this step is important for future iterations of this step. If a charger is not connected, the device enters emergency mode (step 203). The operating system displays this fact using the operating mode indicator 120.

The operating system then repeats steps 200, 202 and 203 until such time that the cell power level rises above 10%, a charger is plugged in, or the phone runs out of power and is switched off.

In a preferred embodiment, when the operating system detects that only 10% of power remains in cell 117, the operating system automatically turns the mobile device 100 off. In this situation, the user knows that they may turn the phone back on, but only to make emergency calls. Alternatively, when the device enters emergency mode, the operating system starts a five minute timer. After five minutes, the mobile device is switched off.

It is highly unlikely that a user will need to make an emergency call when the battery power first reaches 10%. Hence, by switching the device off, further power can be saved.

When the mobile device 100 is switched on, the operating system operates in accordance with Figure 5. If the cell 117 has less than 10% power, and if no charger is connected, the device immediately enters emergency mode. The operating system then starts a timer. After five minutes, the device 100 switches itself back off.

Figure 6 shows a mobile device 300 in a further embodiment of the present invention. The mobile device 300 comprises many of the components of mobile device 100. The mobile device 300 comprises an outer casing 301, an earphone 302, a microphone 303, a keypad 304 and a display 305. These components operate in the same manner as those of mobile device 100.

Figure 7 is a schematic diagram showing the components of the mobile device 300. As can be seen, many of the components are the same as those of mobile device 100. In particular, the device 300 includes a system bus 306, a processor unit 307, memory 308, an earphone controller 309, a microphone controller 310, a display controller 311, a keyboard controller 312, a transceiver 313, a storage device controller 314, an antenna 315 and a storage device 116. The mobile device 300 also includes an electrochemical cell 317, a power sensor 318 The mobile device 300 also includes a back-up electrochemical cell 319. The cell 319 is a back-up power source. As with the cell 317, the cell 319 is able to power all the phone systems via power wires (not shown). The cell 319 is connected to a power sensor 320, which is in turn connected to the bus 306.

The power sensor 320 provides an indication of the amount of power remaining in cell 319.

Figure 8 shows the mobile device 300 operating in normal mode. The power sensor 318 provides the operating system with an indication of the amount of power remaining in the cell 317. This information is then displayed on display 305. A cell power indicator 321 indicates the power remaining in cell 317 as a percentage of the cell's power capacity. The mobile device 300 also displays the mode that the device is currently operating in via operating mode indicator 322. In the present case, the cell 317 is at 55% of capacity and the device is operating in normal mode, as indicated by operating mode indicator 322.

When the power remaining in the cell 317 drops to zero, the device 300 switches to emergency mode and starts drawing power from the back-up cell 319. The device 300 includes a switch (not shown) which disconnects cell 317 and connects cell 319. As can been seen in Figure 9, the cell power indicator 321 shows that the cell 317 has no power remaining in it. The operating mode indicator 322 indicates that the device is running in emergency mode. In addition, the cell power indicator 321 now displays the amount of power remaining in the back-up cell 319. This information is provided by power sensor 320. This provides a further indication to the user that the back-up cell 121 is in use.

When operating in emergency mode, the manner in which the mobile device 300 operates is the same as for mobile device 100 when it is operating in emergency mode. In particular, the mobile device 300 includes a hot key (not shown) for initiating emergency calls. The device 300 also monitors for the presence of a charger, and does not enter, or comes out of, emergency mode if a charge is connected and switched on.

Figure 10 is a flow chart showing the mechanism by which the device 300 operates. Assuming the cell 317 has some power remaining, the operating system will be monitoring the available power, using the power sensor 318 (step 400). If the operating system detects that power remains in cell 317, it will maintain the device in normal mode (step 401). At this step, the operating system displays the available power and the fact that the device is operating in normal mode. The operating system then repeats steps 400 and 401.

Although the power sensor 318 actually takes power readings discretely, the interval between readings is sufficiently short that steps 400 and 401 effectively occur continuously.

If, at step 400, the power sensor 318 indicates that the power available has reduced to zero, the operating system checks to see whether or not the cell 317 is currently being charged (step 402). If the mobile device 300 is being charged, the operating system maintains the device in normal mode and returns to step 400. When the cell power first drops to zero it is highly unlikely that a charger will be connected, otherwise the cell power would not have dropped to zero. However, this step is important for future iterations of this step. If a charger is not connected, the device enters emergency mode and the operating system switches system power to the back-up cell 319 (step 403). The operating system displays this fact using the operating mode indicator 322. The operating system also displays the power remaining in the back-up cell 319 using cell power indicator 321.

The operating system then repeats steps 400, 402 and 403 until such time that the cell power level rises above zero, a charger is plugged in, or the phone runs out of power and is switched off.

In order to prevent the device running out of power unexpectedly, the device 300 may switch to emergency mode while 1% or 2% of power capacity remains in cell 317.

As with the first embodiment, when the operating system detects that no power remains in cell 317, the operating system may automatically turn the mobile device 300 off. Alternatively, when the device 300 enters emergency mode, the operating system may start a five minute timer. After five minutes, the mobile device 300 is switched off.

When the mobile device 300 is switched on, the operating system operates in accordance with Figure 10. If the cell 317 has no power remaining, and if no charger is connected, the device immediately enters emergency mode. The operating system then starts a timer. After five minutes, the device 300 switches itself back off.

In the second embodiment, when a charger is connected, it charges the back-up cell 319 first. If the main cell 317 is charged first, and the charger is disconnected after a short period, then the device would enter normal mode, despite there being little or no power in either cell. By charging the back-up cell 319 first, the device will always have a back-up power supply, or will enter emergency mode, if the main cell 317 has not been charged.

As described above, in emergency mode, the only function available to the user is the ability to make emergency calls. In addition to this, other parts of the phone which would ordinarily be enabled may be disabled. For example, the display may be completely or partially disabled. For example, the graphical user interface may be disabled, and the display may instead provide as simple indication that the device is operating in emergency mode. For example, the device may display an emergency call symbol in one corner of the display, the rest of the display being blank. If the display is completely disabled, an LED on the outer casing may indicate that the device is in emergency mode. In both cases, this would save additional power an lengthen the battery life of the device when in emergency mode. When the device is automatically switched off in emergency mode, as described above, the LED may be used to indicate that the device is operating in emergency mode.

The emergency number which the device dials in emergency mode may be preset by the handset supplier, or it may be set by the user. If the device enables a user to set the emergency number, the device may restrict the user to single emergency number. This prevents the user entering the entire address book as emergency numbers, which would defeat the object of having an emergency mode. In particular the device may permit two emergency numbers, one being a number for the emergency services, another being a number of, for example, a next of kin. In particular, the device may be supplied with a plurality of emergency numbers, together with a limited number of user defined emergency number slots. In particular the device may be supplied with a single user defined emergency number slot.

It will be appreciated having a reserved portion of power for use in emergency situations is particular advantages. The power source may either be a single cell or two cells. With a single cell the device enters emergency mode when a certain threshold is reached. With two cells, the entire back-up cell is reserved for an emergency mode. This invention helps reduce the likelihood that a user is unable to reach the emergency services. In particular, when users find themselves in a situation in which the emergency services are required, they may remain in that situation for considerable time, increasing the chance that their mobile phone will run out of batteries. The present invention helps improve the battery life of the phone in such situations.

In the context of the second embodiment only, i.e. the use of two electrochemical cells in a single device, the second mode does not necessarily need to be an emergency mode. Instead the device may be arranged to operate in a first mode and a second mode. The first mode is used when the first cell is in use. When the first cell has no power remaining, the device uses the back-up cell and operates in the second mode. The second mode is a mode in which the device operates with a reduced set of functions. The functions which are disabled or otherwise controlled may be: reduced display power, prohibited access to power intensive applications such as a media player, prohibited access to data connections, audio, etc. It will be appreciated that a mobile device which operates in two modes, using two cells, in order to conserve power, is not known from the prior art. In the prior art, devices which use different modes all rely on the same power source.

The term "depleteable power source" refers to a power source which is of inherently limited capacity. For example, an electrochemical cell will only provide power for a limited period, after which the cell must be recharged. A mains power source is not depleteable in this sense. Although a mains power source may be disconnected, it is a non-depleteable power source in the context of the present invention.

The term "emergency mode", when used in the context of a mobile device, means the ability of the device to be used for emergency purposes only. A call to the emergency services would be one example of a service provided in an emergency mode. In contrast the term "normal mode" means the operation of the phone with full functionality. It will be appreciated that this does not necessarily mean that every device function is available in normal mode. For example, certain functions may be disabled for other reasons.

Data transfer may be disabled when the phone is in an area of poor reception for example. The phone would still be operating in "normal mode" in such situations.

In the context of the present invention, the term "threshold" means a p redefined proportion of the total power capacity of a device. For example, a 10% threshold is reached when the amount of power remaining in the device is 10% of the power capacity of the device. This can be distinguished from, for example, the interruption of a mains power supply. If a mains power supply is interrupted, causing a device to draw power from another source, the device has not reached a power "threshold".

Various modifications, changes, and/or alterations may be made to the above described embodiments to provide further embodiments which use the underlying inventive concept, falling within the spirit and/or scope of the invention. Any such further embodiments are intended to be encompassed by the appended claims.

Claims

Claims 1. A computing device having at least one power source; wherein the device is arranged to operate in a normal mode while the amount of power available in said at least one power source is above a predefined threshold; and the device is further arranged to operate in an emergency mode, when the amount of power available in said at least one power source is below said predefined threshold.
2. A computing device according to claim 1, wherein said at least one power source is a depleteable power source.
3. A computing device according to claims 1 or 2, wherein emergency mode is a mode in which the only call function which is enabled is an emergency call function.
4. A computing device according to claim 3, wherein the device is further arranged to initiate an emergency call, when in emergency mode, if a user depresses a predefined emergency call key.
5. A computing device according to any preceding claim, wherein the device is further arranged to switch off, when the amount of power available in said at least one power source drops below said predefined threshold.
6. A computing device according to any of claims 1 to 4, further comprising a timer, wherein the device is further arranged to switch off, when the timer indicates that a predefined amount of time has passed since the amount of power available in said at least one power source dropped below said predefined threshold.
7. A computing device according to any preceding claim, further comprising an external indicator arranged to indicate when the device is in emergency mode.
8. A computing device according to claim 7, wherein the external indicator is a visual indicator or an audible indicator.
9. A computing device according to any preceding claim, wherein the device is further arranged to disable a display of the device when the device is in emergency mode.
10. A computing device according to any preceding claim, wherein the at least one power source is at least one electrochemical cell.
11. A computing device according to claim 10, wherein the device is further arranged to operate in normal mode when the at least one electrochemical cell is being charged.
12. A computing device according to any preceding claim, further comprising at least one power sensor arranged to determine the amount of power remaining in said at least one power source.
13. A computing device according to any preceding claim, wherein the device is a mobile phone.
14. A computing device according to claim 13, wherein the mobile phone comprises an outer casing and said at least one power source is positioned within the outer casing.
15. A computing device according to any preceding claim, wherein the device has stored thereon at least one preset emergency number which can not be modified by a user.
16. A computing device according to any preceding claim, wherein the device is further arranged to enable a user to store at least one user defined emergency number.
17. A computing device according to any preceding claim, wherein said at least one power source is a first power source and a second power source; said device is arranged to operate in said normal mode, while the power available in said first power source is above a predefined level, and to draw power from said first source while in normal mode; and said device is further arranged to operate in said emergency mode, when the power available in said first power source falls to said predefined level, and to draw power from said second power source while in emergency mode.
18. A computing device according to claim 17, wherein said first and second power sources are electrochemical cells.
19. A computing device according to claims 17 or 18, wherein said predefined level is zero power.
20. A computing device according to any of claims 1 to 16, wherein said at least one power source is a single power source.
21. A computing device according to claim 20, wherein the predefined threshold is 10%.
22. A method of operating a computing device, wherein the device includes at least one power source, the method comprising: operating the device in a normal mode while the amount of power available in said at least one power source is above a predefined threshold; and operating the device in an emergency mode, when the amount of power available in said at least one power source is below said predefined threshold.
23. A method according to claim 22, further comprising initiating an emergency call, when the device is operating in emergency mode, if a user depresses a predefined emergency call key.
24. A method according to claims 22 and 23, further comprising switching off the device, when the amount of power available in said at least one power source drops below said predefined threshold.
25. A method according to claims 22 and 23, further comprising switching off the device, when a predefined amount of time passes from the time at which the amount of power available in said at least one power source drops below said predefined threshold.
26. A method according to any of claims 22 to 25, further comprising indicating to a user when the device is in emergency mode.
27. A method according to any of claims 22 to 26, wherein the at least one power source is an electrochemical cell, and the method further comprises operating the device in normal mode when the electrochemical cell is being charged.
28. A method according to any of claims 22 to 27, wherein said at least one power source is a first power source and a second power source, and said method further comprises: operating said device in said normal mode, while the power available in said first power source is above a predefined level, and to draw power from said first source while in normal mode; and operating said device in said emergency mode, when the power available in said first power source falls to said predefined level, and to draw power from said second power source while in emergency mode.
29. A method according to any of claims 22 to 27, wherein said at least one power source is a single power source.
30. A computing device having a first electrochemical cell and a second electrochemical cell; wherein the device is arranged to operate in a first mode while the power available in the first electrochemical cell is above a predefined level, and, in said first mode, the device uses said first electrochemical cell for power; and the device is further arranged to operate in a second mode, when power available in the first electrochemical cell drops to said predefined level, and, in said second mode, the device uses said second electrochemical cell for power.
31. A computing device according to claim 30, further comprising an outer case, wherein said first and second electrochemical cells are positioned with said outer case.
32. A computing device according to claims 30 or 31, wherein said second mode of operation is a mode in which the computing device operates with a reduced set of functions when compared with said first mode.
33. A computing device according to claims 30, 31 or 32, wherein said predefined level is zero power.
34. A method of operating a computing device, wherein the device includes a first electrochemical cell and a second electrochemical cell; the method comprising: operating the device in a first mode, while the power available in the first electrochemical cell is above a predefined level, and, in said first mode, using said first electrochemical cell for power; and operating the device in a second mode, when power available in the first electrochemical cell drops to said predefined level, and, in said second mode, using said second electrochemical cell for power.
35. A method according to claim 34, operating the computing device with a reduced set of functions, when compared with said first mode, when in said second mode.
36. A method according to claims 34 or 35, wherein said predefined level is zero power.
37. A computer program or suite of computer programs arranged such that when executed by a computer they cause the computer to operate in accordance with the method of any of claims 22 to 29 and 34 to 36.
38. A computer readable medium storing the computer program, or at least one of the suites of computer programs, according to claim 37.
39. An operating system for causing a computing device to operate in accordance with a method as claimed in any one of claims 22 to 29 and 34 to 36.
40. A computing device substantially as described hereinbefore and as shown in Figure ito 10.