Abstract:
A mobile device ( 200 ) for receiving an audio signal from a source ( 390 ) via a base station ( 300 ) is disclosed. The mobile device comprises a first wireless communication interface ( 220 ) operable to communicate using a first mode of wireless communication; a second wireless communication interface ( 230 )_operable to communicate using a second mode of wireless communication, the second mode having a shorter range than the first mode; and a controller ( 210 ) configured to switch from receiving the audio signal from the base station via the first wireless communication interface to receiving the audio signal via the second wireless communication interface when the mobile device is proximate to the base station.

Description:
FIELD 
       [0001]    This disclosure relates to a mobile device for receiving an audio signal from a source using multiple wireless communication interfaces, and in particular, but without limitation, to switching between wireless communication interfaces according to the proximity of the mobile device to the base station. 
       BACKGROUND 
       [0002]    The use of wireless headsets in office and call centre environments is extremely popular. However, the infrastructure that supports the use of wireless headsets in such environments is facing an increasing number of challenges due to the continually increasing density of such headsets in a given space. 
         [0003]    The preferred technologies used for wireless headsets are Digital Enhanced Cordless Telecommunications, DECT, and Bluetooth. However, both systems have limited bandwidth, which means that only a limited number of headsets can be used simultaneously within a given area. For example, DECT can only provide up to 120 channels for simultaneous communications to be taking place. In the modern call centre environment this is an insufficient number of channels. 
         [0004]    One way to deal with this issue is to provide sufficient geographical separation to enable channel reuse, or by using different systems such as DECT and Bluetooth in parallel. However, spacing call centre workers out sufficiently to enable reuse of channels can be costly in terms of floor space and use multiple systems is far from ideal in terms of system maintenance. 
         [0005]    In recent years, the use of wide band speech has increased which further reduces the number of available bands for DECT communications putting yet further stress on such infrastructure. 
         [0006]    Current wireless office communications systems are therefore inadequate for the modern office and call centre environments. 
       SUMMARY 
       [0007]    According to an aspect of the invention a mobile device is provided for receiving an audio signal from a source via a base station. The mobile device comprises a first wireless communication interface operable to communicate using a first mode of wireless communication, a second wireless communication interface operable to communicate using a second mode of wireless communication, the second mode having a shorter range than the first mode, and a controller configured to switch from receiving the audio signal from the base station via the first wireless communication interface to receiving the audio signal via the second wireless communication interface when the mobile device is proximate to the base station. 
         [0008]    The mobile device may further comprise an energy store. The energy store may be operable to be charged via electromagnetic energy transfer. The energy store may be operable to be charged via electromagnetic energy transfer from the base station. The mobile device may be configured to charge the energy store when the mobile device is proximate to the base station. 
         [0009]    The controller may be configured to switch from receiving the audio signal from the base station via the second wireless communication interface to receiving the audio signal via the first wireless communication interface when the mobile device is not proximate to the base station. The controller may be further configured to determine a parameter indicative of a proximity of the mobile device to the base station. The switching may be based on the parameter. The parameter may be the presence of a signal of the second mode of wireless communication at the second wireless communication interface above a threshold level. The parameter may be the presence of electromagnetic energy above a threshold level. 
         [0010]    The mobile device may further comprise a wired communication interface. The controller may be further configured to transmit the audio signal to a headset via the wired communication interface. 
         [0011]    The controller may be further configured to establish an association between the mobile device and the base station via the second wireless communication interface. 
         [0012]    According to another aspect of the invention a base station for transmitting an audio signal to a mobile device is disclosed. The base station comprises a first wireless communication interface operable to communicate using a first mode of wireless communication, a second wireless communication interface operable to communicate using a second mode of wireless communication, the second mode having a shorter range than the first mode, and a controller configured to switch from transmitting the audio signal to the mobile device via the first wireless communication interface to transmitting the audio signal to the mobile device via the second wireless communication interface when the mobile device is proximate to the base station. 
         [0013]    The base station may further comprise a charger operable to charge an energy store of the mobile device. The charger may charge the energy store via electromagnetic energy transfer. 
         [0014]    The first wireless communication interface may be a radiofrequency communication interface. The second wireless communication interface may be an optical communication interface. The second wireless communication interface may be an infrared interface. 
         [0015]    The second wireless communication interface may be an inductive communication interface. 
         [0016]    According to yet another aspect of the invention a method of operating the mobile device as described herein or operating the base station as described herein is provided. 
         [0017]    According to a further aspect of the invention a computer-readable medium carrying computer-readable instructions arranged, upon execution by a processor, to cause the processor to carry out any method disclosed herein is disclosed. 
         [0018]    Also disclosed is a method for transmitting an audio signal from a base station to a mobile device. The base station comprises: a first wireless communication interface operable to communicate using a first mode of wireless communication; and a second wireless communication interface operable to communicate using a second mode of wireless communication, the second mode having a shorter range than the first mode; and the method comprising switching from transmitting the audio signal to the mobile device via the first wireless communication interface to transmitting the audio signal to the mobile device via the second wireless communication interface when the mobile device is proximate to the base station. The base station may further comprise a charger operable to charge an energy store of the mobile device via electromagnetic energy transfer. 
         [0019]    A receiver suitable for receiving an audio signal from a source via a base station is also disclosed. The receiver comprising: a first wireless communication interface operable to communicate using a first mode of wireless communication; a second wireless communication interface operable to communicate using a second mode of wireless communication, the second mode having a shorter range than the first mode; an energy store operable to be charged via electromagnetic energy transfer; and a controller configured to: receive the audio signal from the base station via at least one of the first wireless communication interface and the second wireless communication interface; stop receiving the audio signal from the base station via the first wireless communication interface when the receiver is proximate to the base station. 
         [0020]    Also disclosed is a base station suitable for transmitting an audio signal to a receiver, the receiver comprising: a first wireless communication interface operable to communicate using a first mode of wireless communication; a second wireless communication interface operable to communicate using a second mode of wireless communication, the second mode having a shorter range than the first mode; a charger operable to charge the receiver via electromagnetic energy transfer; and a controller configured to: transmit the audio signal to the receiver via at least one of the first wireless communication interface and the second wireless communication interface; stop transmitting the audio signal to the receiver via the first wireless communication interface when the receiver is proximate to the base station. 
         [0021]    The controller disclosed herein may be configured to determine a parameter indicative of a proximity of the receiver to the base station. Receiving the audio signal from the base station via the first wireless communication interface when the receiver is not proximate to the base station may comprise receiving the audio signal from the base station via the first wireless communication interface when the parameter indicates that the receiver is not proximate to the base station. Receiving the audio signal from the base station via the second wireless communication interface when the receiver is proximate to the base station may comprise receiving the audio signal from the base station via the second wireless communication interface when the parameter indicates that the receiver is proximate to the base station. 
         [0022]    The first wireless communication interface may be DECT compliant. The second wireless communication interface may be Infrared Data Association, IrDA, compliant. The second wireless communication interface may receive audio signals in the Sony/Philips Digital Interface Format, S/PDIF. 
         [0023]    The wired communication interface disclosed herein may comprise a quick-disconnect fitting. 
         [0024]    Also disclosed herein is a base station suitable for transmitting an audio signal to a receiver, the base station comprising: a first wireless communication interface; a second wireless communication interface suitable for optical communication; and a controller configured to: determine a parameter indicative of a proximity of the receiver to the base station; transmit the audio signal to the receiver via the first wireless communication interface when the parameter indicates that the receiver is not proximate to the base station; transmit the audio signal to the receiver via the second wireless communication interface when the parameter indicates that the receiver is proximate to the base station. 
         [0025]    A wireless receiver is disclosed comprising: a first wireless communication interface; a second wireless communication interface; a wired communication interface; and a controller, wherein the first wireless communication interface is a radiofrequency communication interface and the second wireless communication interface is an optical communication interface, and wherein the controller is configured to: receive an acoustic signal from a docking station via the first wireless communication interface when the wireless receiver is within a given proximity of the docking station; receive the acoustic signal from the docking station via the second wireless communication interface when the wireless receiver is not within a given proximity of the docking station; and transmit the acoustic signal via the wired communication interface. 
         [0026]    An energy level of the energy store can be increased by electromagnetic energy transfer. 
         [0027]    Also disclosed is a docking station comprising: a first wireless communication interface; a second wireless communication interface; and a controller, wherein the first wireless communication interface is a radiofrequency communication interface and the second wireless communication interface is an optical communication interface, and wherein the controller is configured to: transmit an acoustic signal to a wireless receiver via the first wireless communication interface when the wireless receiver is within a given proximity of the docking station; transmit the acoustic signal to a wireless receiver via the second wireless communication interface when the wireless receiver is not within a given proximity of the docking station. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    Examples of the present disclosure will now be explained with reference to the accompanying drawings in which: 
           [0029]      FIG. 1  is a diagram showing an application scenario for the methods and apparatuses described herein in which a headset is connected to a base station over a long-range wireless connection via a mobile device; 
           [0030]      FIG. 2  is a diagram showing the application scenario of  FIG. 1  with the headset connected to the base station over a short-range wireless connection via the mobile device; 
           [0031]      FIG. 3  illustrates the structure of the mobile device and the base station shown in  FIGS. 1 and 2 ; and 
           [0032]      FIG. 4  is a flow diagram of the steps of a method described herein performed by the mobile device and base station shown in  FIG. 3 . 
       
    
    
       [0033]    Throughout the description and the drawings, like reference numerals refer to like parts. 
       DETAILED DESCRIPTION 
       [0034]    The present disclosure relates to a headset system that is capable of switching communications to and from the headset between different communications channels having different communication ranges. In particular, a short-range communication channel is used where possible to relay an audio signal to the headset in order to minimise demand on a long-range communication channel. 
         [0035]    In order to better understand the methods described herein, an exemplary application scenario of the headset system shall now be described with reference to  FIGS. 1 and 2  with  FIG. 1  illustrating the system working in a long-range communication mode and  FIG. 2  illustrating the same system working in a short-range communication mode. 
         [0036]    In  FIG. 1 , a user U 1  is working in a call centre. A base station  300  is connected to a communications device, in this case a telephone  390 . However, it will be appreciated that the audio source could be various other devices such as a computer. The base station  300  acts as a transceiver arranged to receive an audio signal from the telephone  390  and wirelessly transmit the audio signal to a mobile device  200 . The mobile device  200  is in turn connected to a headset  290 , worn by the user U 1 . The mobile device  200  therefore acts as a transceiver for the wireless headset  290 . The mobile device  200  is therefore arranged to receive the audio signal from the base station  300  and then transmit the received audio to the headset  290  to be played through speakers in the headset  290  for the user to listen to the audio. Similarly, audio can pass from a microphone in the headset in the opposite direction towards the telephone. 
         [0037]    In  FIG. 1 , the mobile device  200  may be attached to the user U 1 , for example by clipping onto the user&#39;s clothing. A wired connection is then provided between the mobile device  200  and headset  290 . This wired connection may utilise a quick disconnect plug so that the headset can be easily disconnected. 
         [0038]    In the arrangement shown in  FIG. 1 , there is sufficient distance between the user U 1 , and therefore the mobile device  200  which is attached to the user, and the base station  300 . Consequently, a long-range wireless communication channel is used. In the arrangement of  FIG. 1  this channel is a DECT channel. How the system determines that the distance is sufficient to use the long-range channel shall be discussed in detail with reference to  FIG. 4 . 
         [0039]      FIG. 2  illustrates the same system as  FIG. 1 , except in this case the user U 1  is sitting at a desk where the base station  300  is located. The user U 1  is therefore able to dock the mobile device  200  with the base station  300  such that a short-range communication channel can be used between the mobile device  200  and the base station  300 . The base station has a receiving portion in which the mobile device  200  can be docked. The receiving portion may be arranged to loosely receive the mobile device such that it is easy for the user U 1  to place the mobile device  200  in the receiving portion without the need for connecting any wires or any plug-socket type arrangement. For example, the receiving portion of the base station  2  is preferably bowl shaped. This has the advantage of making it easy for the user U 1  to place the mobile device  200  in the bowl shaped receiving portion of the base station  300 . A consequence of this docking process is that a DECT channel is no longer used, which increases the DECT bandwidth available within the call centre. In the arrangement of  FIG. 2 , the audio signal is transmitted from the base station  300  to the mobile device  200  using infrared. Infrared has the advantage of providing a strong, secure short-range connection, and enables some tolerance between the position of the transmitter and receiver involved in the communication. 
         [0040]    The components of the mobile device  200  and base station  300  shall now be discussed in detail with reference to  FIG. 3 . 
         [0041]    The base station  300  is connected to the telephone  390  via a direct wired connection. This connection allows for two-way audio communications between the base station  300  and the telephone  390 . The base station is then able to transmit and receive audio signals to the mobile device  200  via either a short-range wireless communication interface  330  or a long-range wireless communication interface  320 . The long-range wireless communication interface  320  is a DECT interface, which transmits and receives signals using antenna  322 . The short-range wireless communication interface  330  is an infrared interface, which transmits and receives signals using an infrared transceiver  332 . The controller  310  switches from the long-range wireless communication interface  320  to the short-range wireless communication interface  330 , and vice versa, according to the proximity of the mobile device  200  to the base station  300 . The base station  300  includes a charger  340  for inductively charging the mobile device  200  when the mobile device  200  is sufficiently close to the base station  300  to enable inductive charging. 
         [0042]    The mobile device  200  transmits and receives audio signals to and from the base station  300  via a corresponding short-range wireless communication interface  230  or a corresponding long-range wireless communication interface  220 . The long-range wireless communication interface  220  is a DECT interface, which sends and receives the audio signal using antenna  222 . The short-range wireless communication interface  230  is an infrared interface, which sends and receives the audio signal using an infrared transceiver  232 . The controller  210  switches from the long-range wireless communication interface  220  to the short-range wireless communication interface  230 , and vice versa, according to the proximity of the mobile device  200  to the base station  300 . The mobile device  200  includes an energy store  240 , which can be inductively charged by the charger  340  in the base station  300  when the mobile device  200  is sufficiently close to the base station  300  to enable inductive charging. 
         [0043]    The way in which the mobile device  200  and base station  300  switch between the long-range and short-range modes of operation shall now be discussed in more detail with reference to  FIG. 4 . To simplify the explanation reference shall be made to audio being transmitted from the telephone  390  to the headset  290 . However, it will be appreciated that the same principles apply for audio being transmitted from the headset to the telephone  390 . 
         [0044]    In a first step S 100 , an association is established between the mobile device  200  and the base station  300 . In this arrangement the pairing is performed via signals sent between the mobile device  200  and base station  300  over the short-range wireless communication channel defined by the respective short-range wireless interfaces. This pairing step determines the mobile device  200  to which the base station  300  should send audio. The process is secure as the association is established via infrared signals, which are more difficult to intercept or transmit from outside the room in which the mobile device  200  and base station  300  are present. It will be appreciated that this first step could be performed by a manufacturer prior to shipping a product. As such, this step may not be required in some arrangements. 
         [0045]    In step S 200 , the mobile device  200  or the base station  300  determines whether the mobile device  200  is proximate to the base station  300 . This is done by determining a parameter indicative of the proximity of the mobile device  200  to the base station  300 . This detection and switching process will be discussed in more detail. 
         [0046]    If the mobile device  200  is proximate to the base station  300 , in step S 300  the charger  340  in the base station  300  inductively charges the energy store  240 . The charger  340  only emits power for charging the energy store  240  once it receives a signal indicating that short-range communications are taking place. This helps to reduce unnecessary power wastage. 
         [0047]    In step S 400   b,  the mobile device  200  then receives the audio signal transmitted by the base station  300  via the short-range wireless communication interface  230 . If the mobile device  200  is not proximate to the base station  300 , in step S 400   a,  the mobile device  200  instead receives the audio signal transmitted by the base station  300  via the long-range wireless communication interface  220 . 
         [0048]    In step S 500 , the mobile device  200  then transmits the audio signal to the headset  290 . 
         [0049]    The process of switching between the long-range and the short-range communications channels shall now be discussed in detail. 
         [0050]    The base station  300  continuously monitors the proximity of the mobile device  200  to the base station  300 . The base station controller  300  can therefore control the switching between the wireless communication interfaces as the proximity changes. 
         [0051]    If the mobile device  200  is proximate to the base station  300  and communicating using short-range communication, then the base station  300  is continually monitoring the presence of the infrared signal from the mobile device  200 . As soon as the infrared signal is determined to no longer be present, for example due to the mobile device  200  being removed from the receiving portion of the base station  300 , the base station controller  310  will switch to sending the audio signal via the long-range wireless communication interface. The mobile device  200  is then able to detect that it has changed from short-range communications by virtue of the fact that it can now receive a long-range communication signal. As such, the mobile device controller  210  switches communications from the short-range communication interface  230  to the long-range communication interface  220 . The controllers are able to perform this switching functionality seamlessly and without interruption. 
         [0052]    If long-range communications are taking place, the switching occurs upon detection of the presence of the mobile device  200  in the receiving portion of the base station  300 . In this case, the base station  300  continuously or periodically transmits an infrared signal, and waits for the signal to be detected by the mobile device  200 . In practice the infrared signal will only be detected by the mobile device  200  when the mobile device  200  is within the receiving portion of the base station  300 . When the mobile device  200  determines that it is proximate to the base station  300  it then transmits a signal back to the base station to inform the base station  300  that it is within range for short-range wireless communication. This signal is transmitted via infrared. The controllers of the base station  300  and mobile device  200  then switch communications channels to short-range communications. 
         [0053]    An advantage of this switching process is that by ceasing to use the long-range wireless communication channel, the number of mobile devices  200  using the limited number of available DECT channels is reduced. 
         [0054]    The system described herein is capable of achieving very high density deployments. In addition, it allows for an infinite number of headsets in the same office or call centre. It allows for improved sound quality due to freeing up bandwidth to enable use of wide band codecs. The system allows for additional security to be introduced by adding cross-technology exchange of link-keys. Another advantage of the system is that it provides increased flexibility for workers to work at or away from their desk. The embodiment of the system described above required no mechanical contacts, all contacts are wireless therefore making the system easy to use and simplifies the process of switching between long-range and short-range communications. 
         [0055]    Although a detailed example of at least one aspect of the present invention is described above, certain modifications to the above example would be obvious to a person of ordinary skill in the art. As such, the scope of the invention is limited only by the accompanying claims. 
         [0056]    Although the above description focuses on the mobile device  200  receiving an audio signal from a base station  300 , if the headset  290  connected to the mobile device  200  has a microphone, the mobile device  200  will also transmit an audio signal to the base station  300 , and will switch from transmitting the audio signal via the long-range wireless communication interface  220  to transmitting the audio signal via the short-range wireless communication interface  230 , and vice versa, according to the proximity of the mobile device  200  to the base station  300 . In alternative arrangements, the system will only be capable of one-way communication. For example, in one arrangement the system is used to transmit audio from a source to a headphone. In such an arrangement, the system can be used for music streaming. 
         [0057]    It will be appreciated that the long-range communications enable communications with a greater distance between the mobile device  200  and base station  300  compared to short-range communications. 
         [0058]    Although in the present disclosure the short-range wireless communication interfaces  230  and  330  are infrared interfaces, it will be appreciated that these interfaces could use other wireless technologies. For example, these interfaces could be optical interfaces using other wavelengths. Alternatively, the interfaces could be inductive communication interfaces. For example, an audio signal could be modulated onto the inductive charging signal. In other arrangements, the short-range wireless communication interfaces  230  and  330  could even be replaced with conductive communication interfaces such as conductive connectors. 
         [0059]    Similarly, the long-range communication interfaces  220  and  320  could use radiofrequency signals at other frequencies, or use other wireless transmission protocols (e.g. WiFi®, Bluetooth®, etc.). 
         [0060]    Instead of being charged by the base station  300 , the energy store  240  may be charged by any charger (whether inductive or wired); in this case, the energy store  240  could be charged whether the mobile device  200  is proximate to the base station  300  or not. 
         [0061]    While the above description discusses the switching process taking place in response to the presence or absence of the short-range wireless signal, it will be appreciated that the switching may be triggered by various other means. In one alternative arrangement, a determination as to the proximity of the mobile device  200  to the base station  300  is carried out based on a strength of a signal transmitted from the long-range wireless communications interface  220  of the mobile device and received at the long-range wireless communication interface  320  of the base station  300 . In particular, in such an arrangement the base station  300  is able to approximate the distance of the mobile device  200  from the base station  300  based on the signal strength being received at the base station  300  from the mobile device  200  when the system is operating using long-range wireless communication. A threshold is set to indicate that the mobile device  200  is sufficiently close to enable short-range communications. This process is preferable in arrangements where the short-range communications are not infra-red, but have a slightly larger range. 
         [0062]    In other arrangements separate sensing is provided to initiate the switching between long-range and short-range communications. 
         [0063]    It will be appreciated that the turning on and off of the charging functionality may work independently of the switching between long and short range communication channels. 
         [0064]    While the mobile device and headset are shown as separate devices, it will be appreciated that in certain arrangements these devices may be integrated. For example, a mobile device may be provided with the functionality of the headset or a headset may be provided with the functionality of the mobile device. 
         [0065]    It will also be appreciated that while the base station and telephone are described as separate components, their functionality may be combined. In fact, the functionality of the base station may be incorporated within any communications interface device such as a telephone, computer or such like. 
         [0066]    In other arrangements, further communications channels could be provided such that there are more than two communications channels. For example, cellular communications could be added as a third range of communications which is used when the mobile device is too far from the base station for the long-range wireless communications channel to work satisfactorily. 
         [0067]    The approaches described herein may be embodied on a computer-readable medium, which may be a non-transitory computer-readable medium. The computer-readable medium may carry computer-readable instructions arranged for execution upon a processor so as to make the processor carry out any or all of the methods described herein. 
         [0068]    The term “computer-readable medium” as used herein refers to any medium that stores data and/or instructions for causing a processor to operate in a specific manner. Such storage medium may comprise non-volatile media and/or volatile media. Non-volatile media may include, for example, optical or magnetic disks. Volatile media may include dynamic memory. Exemplary forms of storage medium include, a floppy disk, a flexible disk, a hard disk, a solid state drive, a magnetic tape, or any other magnetic data storage medium, a CD-ROM, any other optical data storage medium, any physical medium with one or more patterns of holes, a RAM, a PROM, an EPROM, a FLASH-EPROM, NVRAM, and any other memory chip or cartridge.