TECHNICAL FIELD

The present invention relates to a method and device for generating ringer signal in a communication device and more specially an adaptive ringer signal.

BACKGROUND

Communication devices, such as cellular telephones, have become increasingly versatile. For example, cellular telephones today often include applications that allow users to do more than just make and receive telephone calls, such as send/receive text messages, play music, play video games, take pictures, etc. As a result, cellular telephones have become an increasingly common part of every day life for a large number of users.

The becoming of the common part of every day life means that the cell phone is carried around in some way. Usually it is carried in the packet, case, haversack, or an especial cover.

Moreover, having the cell phone carried around implies that it is often used in noisy environments. A problem arises when a wireless device such as a cellular phone and/or wireless pager device that is in a noisy environment rings or is otherwise activated. The owner of the ringing or beeping wireless device may not hear the tone at all or in time to respond to it.

Most cell phones include mechanisms for adjusting a loudness of a ringer. Some devices provide user interfaces for defining multiple signalling profiles, where each profile specifies a behaviour that the ringing device and/or the vibrating device are to exhibit upon detection by the phone handset of an incoming call. A user of these devices can manually select the appropriate signalling profile in accordance with his or her immediate physical environment.

A way of alerting the cell phone user is using adaptive level for ring signal or other alerting signals. An easy way to have adaptive level for sound output, e.g. ringer, alarm etc., is to check the input level of the microphone, i.e. noisy then high level and quiet then low level. However, this method does not work very well when the device is carried in a pocket, bag or similar carriers.

SUMMARY

There is an apparent need for alerting devices that appropriately handle announcement of, e.g. incoming calls, without requiring users to manually attend to device settings. This can be achieved by checking the coupling between the microphone and the loudspeaker of the device. When the device is carried in, for example, a pocket the input level is likely to be low and the coupling bad.

It is thus desirable to implement a system in which the device having an alert signal generator could detect the environment, in which of the device is carried, whereby the output level of the alerter can be increased and alerts or missed calls can be avoided.

This is enabled using acoustic coupling to detect the user case when the device is in a pocket or similar.

According to a first aspect of the invention a method is provided for of adapting an alert signal level generated by a device to an ambient of said device. The method comprises the steps of: processing a sound signal corresponding to a test signal or an alert signal, generating a correlation value by correlating said sound signal with a generated sound signal, comparing said correlation value with a value, and adjusting said alert signal to a level based on result of said comparison. Preferably, the sound signal is received by a microphone and the test signal is generated by a speaker or a ringer. Preferably, the correlation value is correlation between said microphone and said speaker.

The method may be used to detect ambient which may be an environment made of a material which damps said sound signal. Preferably, the material is fabric or textile.

According to a second aspect of the invention a method of adapting an alert signal level generated by a device to an ambient of said device. The method comprises the steps of: activating an alert, activating a microphone, picking up background sound by the microphone, checking the sound level: if high sound level: generate a loud alert, if low sound level: generating a test or alert signal, check the correlation between said speaker output and microphone input, if low correlation: increasing output sound level, if high correlation: generate said alert at that level, if very high correlation: decrease the sound output level.

According to a third aspect of the invention a method of adapting an alert signal level generated by a device to an ambient of said device. The method comprises the steps of: activating an alert, activating a microphone, picking up background sound by the microphone, checking the sound level: if high sound level: generating a loud alert, if low sound level: generating a test or alert signal, gradually increasing the sound level until a good level of correlation is reached.

The invention also relates to an arrangement for adapting an alert signal level generated by a device to an ambient of said device. The arrangement comprises: a processing unit for processing a sound signal corresponding to a test signal or an alert signal, means for generating a correlation value by correlating said sound signal with a generated sound signal, means for comparing said correlation value with a predetermined value, and means for adjusting said alert signal to a level based on result of said comparison. The device further comprises a microphone for receiving said sound signal. The device further comprises a speaker or a ringer for generating said test signal. The correlation value is correlation between said microphone and said speaker.

The invention also relates to a mobile communication terminal comprising an antenna for receiving/transmitting RF signals as between the terminal and a cell site antenna of a wireless/cellular telecommunications network, a transceiver associated with the antenna for processing incoming and outgoing signals, call processing components for controlling operation of the terminal, and user interface components for providing an interface between the terminal and a user. The mobile communication terminal further comprises an arrangement for adapting an alert signal level generated by said mobile communication terminal to an ambient of said terminal. The arrangement comprises: a processing unit for processing a sound signal corresponding to a test signal or an alert signal, means for generating a correlation value by correlating said sound signal with a generated sound signal, means for comparing said correlation value with a value, and means for adjusting said alert signal to a level based on result of said comparison. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings:

Fig. 1 is a perspective view of a portable telephone in connection with which the present invention can be used; Fig. 2 is a schematic diagram of a portable telephone system in accordance with the present invention;

Fig. 3 is a flow chart showing an alert signal level adapting process in accordance with the present invention; and

Fig. 4 is a flow chart showing an alert signal level adapting process in accordance with another embodiment of the present invention.

DETAILED DESCRIPTION

A "device," as the term is used herein, is to be broadly interpreted to include any portable device having a microphone and a loudspeaker such as radiotelephone; a personal communications system (PCS) terminal that may combine a cellular radiotelephone with data processing; a personal digital assistant (PDA) that can include a radiotelephone, pager, Internet/intranet access, web browser, organizer, calendar, a camera (e.g., video and/or still image camera), a sound recorder, and/or global positioning system (GPS) receiver; a GPS device; a camera (e.g., video and/or still image camera); a sound recorder; and any other computation or communication device capable of displaying media, etc.

In the following the invention is described in an exemplary way with reference to a cell phone.

When there is a lot of background noise it can be difficult to hear the ring or any other alert signals. With ordinary adaptive ringer level the output level is normally adjusted depending on the noise level. This will increase the ringer level when the noise is high (high input on microphone) and decrease it in a silent environment (low input on microphone). This does not work very well when the phone is kept in a pocket, handbag or similar (as it often is). For this case the input to the microphone will be quite low which indicates a quiet environment. Therefore the output (ringer or alarm) will be low when it actually should be high since much of the output is likely to be absorbed by the material of the ambient carrying, e.g. fabric, textile, etc. Table 1 illustrates the relation between the input, environment and the ringer level for a cell phone.

Table 1

A way to overcome this problem is to monitor the cross-correlation (correlation or coupling) between the speaker and the microphone. Generally, the cross-correlation is a measure of similarity of two signals, commonly used to find features in an unknown signal by comparing it to a known one. It is a function of the relative time between the signals.

When the cell phone is lying on a flat surface in a quiet room, for example, the correlation between the speaker and the microphone is very good. This correlation may also be used for echo cancellation during speaker phone mode. When the phone is carried in a pocket or something else made out of fabric, like a handbag, the correlation will be inferior since the microphone and/or the loudspeaker is likely to be blocked and/or damped. Table 2 illustrates the relation between the input, correlation, environment and the ringer level for a cell phone.

Table 2

The correlation check can be carried out whilst a sound (ring tone, alarm signal or similar) is generated. One method according to the invention, as illustrated in Fig. 3, comprises the steps of: • Activate an alert (300),

• Activate the microphone (302),

« Pickup the sound (303) by the microphone (background sound is picked up), • Check (304) the sound level: o If (305) high level:

^■ Generate (306) a loud alert o If (305) low level:

^■ Start generating (307) a test or alert signal o Check (308) the correlation between (loudspeaker) output and

(microphone) input

^■ If (309) low correlation:

• Increase (310) output level

^■ If (309) high correlation: • Generate (311) alert at that level

^■ If (309) very high correlation:

• Decrease (312) output level o Loop back and recheck (308) correlation

Another way of doing it, as illustrated in Fig. 4, could be to start (407) to generate the signal at low level and then gradually increase (410) it until a good level of correlation is reached. Other steps relate to same steps as method of Fig. 3.

This process could either be performed from the start or during the entire time that the alert signal is played, following steps 308-312, with step 311 looped back without a change in output level. When the device is removed from the pocket or bag it could lower the output level.

Referring to Figs. 1 and 2, a mobile communication terminal system 10 or handset (cell phone) is illustrated. Generally, the handset 10 includes: a housing 11 including an antenna 12 for receiving/transmitting RF signals as between the handset 10 and a cell site antenna of a wireless/cellular telecommunications network; transceiver 14 associated with the antenna 12 for processing incoming and outgoing signals, call processing components 16 for controlling operation of the handset 10, and user interface components 18 for providing an interface between the handset 10 and the user.

The transceiver 14 may include an incoming signal processing unit and an outgoing call processing unit (not shown). The incoming signal processing unit performs a number of functions relative to an incoming call signal including: filtering the incoming signal to remove unnecessary wavelength bands, demodulating the high frequency carrier signal and converting the signal into a digital format for processing by the call processing component 16. The outgoing call processing unit performs a number of functions relative to transmitting a signal including processing a voice or other signal for transmission, synthesizing the communication signal to apply a reference frequency, modulating the communication signal into a high frequency carrier signal and filtering the resulting signal for transmission.

The call processing components 16 includes a processor (CPU) 161 and a memory and I/O unit 162, a timing subsystem 163, a call indicator control subsystem 164 and an optional messaging subsystem. Operation of the timing system 163, control system 164 and messaging system will be described in more detail below. The processor 161 controls operation of the various components of the handset 10. In this regard, the processor 161 receives an incoming signal from the incoming signal processing unit, and notifies the subscriber of the incoming call. The processor 161 also communicates with cell site/switch equipment via the outgoing call processing unit 16 and antenna 12 to establish a channel for communication as between the handset 10 and a calling telephone that originated the incoming call signal. With respect to outgoing calls, the processor 161 receives information from the user interface components 18, e.g., a phone number and transmit signal, communicates with cell site/switch equipment via the transceiver 14 and antenna 12 to establish a communications channel, transmits a call request and waits for a response from the called telephone/network. During a phone conversation, the processor 161 receives voice communications from the user interface components 18, transmits the voice communications, receives incoming signals, transmits voice communications to the user interface components 18, and detects any operating signals such as a hang up signal.

The user interface components 18 include a number of devices for communicating with the subscriber. The display 181 provides a visual presentation of a phone number entered by the user, information regarding an incoming call and/or various operating information such as status of the handset's battery. The keypad 182 may include buttons corresponding to the numbers 0-9 for entering phone numbers or other numerical information as well as various other buttons such as "end", "off, "#", "*", "flash", "send", or other buttons. The ear piece 183 or a loudspeaker receives communication information from the processor 161 and provides audio signals to the subscriber. Microphone 184 receives voice or other audio signals from the subscriber and provides corresponding communication signals to the processor 161. Finally, the call indicator 185 provides a signal to the subscriber that notifies the subscriber of an incoming call. For example, the call indicator 185 may be a ringer or other device for providing an audio indication, a vibrator, or any other device which provides a signal that is perceptible by the subscriber. The loudspeaker 183 may be part of or connected to the call indicator 185. Moreover, the call indicator 185 may also be used for generating other alert signals, such as alarm signals.

The call indicator 185, the keypad 182 may include a temporary ringer silencer input key and answering input key, the timing subsystem 163, processor 161 , control subsystem 164 and optional messaging subsystem are of particular significance with respect to understanding the adapted alert level control system of the present invention. In the active indicator mode, upon receiving an incoming call signal, the processor 161 in cooperation with the control subsystem 164 activates the call indicator 185 to notify the subscriber of the incoming call. The call indicator 185 is activated throughout the time period between receipt of the incoming call signal (or output of an alert signal) and receipt of an answering input signal from the keypad 182. Upon reception of a call, the processor 161 activates the call indicator 185 or the loudspeaker 183 and the microphone. The sound generated by the call indicator/speaker is picked up with the microphone 184. The signal from the microphone 184 is analysed by the processor 161 , which means that the level of the microphone is checked and if it is low the cross-correlation between the microphone input and the loudspeaker output signals is calculated according to the process described earlier. If the level on the microphone is low, the signal generated at low level. If the correlation is bad, the level of the alert signal is gradually increased until the correlation is good enough which indicates that the output is loud enough. Predefined levels of correlation may be stored in the memory 162, which are used as a lookup table for the processor 161. In the case of a ringer, the ringer will sound periodically throughout the abovementioned answering time period. If an answering input is not received within a given time, as measured by reference to the timing subsystem 163, the processor 161 may transmit a hang up or other signal by which the calling telephone is notified that the subscriber is unavailable.

In a further implementation, the user may select, e.g., by a keystroke or menu entry, a deactivation prior to receipt of an incoming call to preset the handset 10 for temporarily inactive mode operation. In this regard, the processor 161 may control the handset's ringer to provide a single ring or an abbreviated "ping" ring, after which the ringer will remain silent until the call is answered or the time for answering expires.

According to one embodiment of the invention, one or several of alert signals, e.g. related to alarm, received Short Messages Services (SMS), Multi-Media Messages Services (MMS), e-mails, etc., may use the method of the invention. In this case when a message is received by message subsystem 165, the processor 161 is notified, which generates a test tone through the speaker/call indicator 184/185 and picks up the response by means of the microphone 183 and looks up for the correlation for adaptive signal level as described above.

In one additional embodiment, the processor may carry out periodical tests by generating a sound and picking it up the sound with the microphone to determine the ambient noise.

The principles of the invention may be used for any product that make use of the information if it packed in fabric (or some other absorbing material) or not. A small loudspeaker and a small microphone could be attached on products solely for this purpose.

It should be noted that the word "comprising" does not exclude the presence of other elements or steps than those listed and the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements. It should further be noted that any reference signs do not limit the scope of the claims, that the invention may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware. The above mentioned and described embodiments are only given as examples and should not be limiting to the present invention. Other solutions, uses, objectives, and functions within the scope of the invention as claimed in the below described patent claims should be apparent for the person skilled in the art.