Abstract:
A system allows a user who uses a portable communications device (for example, a cell phone or PDA) to answer telephone calls to use service features (for example, call forwarding) that are available on a communications system (for example, a corporate communications system), even though the portable device is not a part of the communications system. A transceiver in the telephone establishes a wireless link with a transceiver in a local communications device (for example, a workstation) of the communications system. The user then causes a transfer instruction to pass over the wireless link to the local communications device. This instruction causes the communications connection to be transferred to the local communications device such that the local communications device can be used to handle the call. After the transfer, service features available on the communications system are available to service the call.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
         [0001]    This application is based on and hereby claims priority to German Application No. 102 12 137.0 filed on Mar. 19, 2002, in Germany, the contents of which are hereby incorporated by reference.  
         TECHNICAL FIELD  
         [0002]    The present invention relates to a method for transferring a communications connection from a portable device to a local communications device.  
         BACKGROUND  
         [0003]    A present-day central communications system generally provides a multiplicity of service features at the various local fixed communications devices of the communications system. These service features are regarded by many users as an indispensable component of everyday communications support. Such service features may include, for example, the familiar functions of “query”, “hold”, “forward”, “broker&#39;s call”, “conference call”, etc., which are standard components of modern communications systems.  
           [0004]    In order to be able to guarantee constant availability, many users also use portable communications devices along with their local fixed communications device. Portable communications devices include, for example, cells phones or mobile communications terminals or mobile computer units. Examples of such portable devices include PDAs (Personal Digital Assistant), notebook computers, etc. Portable devices of this type are carried almost constantly by a growing number of people. These portable devices are mobile and are often personal in nature and therefore are not generally part of the described communications system.  
           [0005]    A user may, for example, keep a portable device for private use, but may also use this portable device for business purposes within the company. The user also has a fixed local communications device (for example, a line-connected telephone disposed at the user&#39;s workstation or integrated into the user&#39;s workstation) that is part of the company&#39;s internal communications system. If the user answers a telephone call using the portable device, then the service features that the user would have otherwise had available had the user answered the call using the fixed local communications device are not available for use with the call. The user may, for example, want to “forward” the call to another person in the company, but this is not possible. A solution is desired.  
         SUMMARY  
         [0006]    A system and method are provided whereby a user who uses a portable device (for example, a cell phone or PDA) to answer telephone calls can use service features (for example, “call forwarding”) available on a communications system (for example, an internal company communications system), even though the portable device is not a part of the communications system. In one embodiment, the portable device is used to set up or otherwise handle a communications connection (for example, a telephone call). The portable device is not part of the communications system, so the service features provided by the communication system are not available for use with the communications connection. Then, according to one embodiment of the invention, the communications connection is transferred to a local fixed communications device (for example, a telephone or workstation or a communications terminal or a data terminal) that is a part of the communications system.  
           [0007]    The transfer of the communications connection from the portable device to the local communications device is carried out using a wireless communications link. The wireless link may, for example, be a two-way Bluetooth microwave communication link. A first Bluetooth transceiver unit is embodied in the local fixed communications device. A second Bluetooth transceiver unit is embodied in the portable device. When the two transceivers are within a communication range of each other, the wireless link is automatically established. To cause the communications connection to be transferred, the user presses a button on the portable device, or activates a touch-sensitive area on the portable device, or otherwise activates the portable device with a spoken command. This user action causes a transfer instruction to be sent via the wireless link from the portable device to the local fixed communications device.  
           [0008]    The local communications device receives the transfer instruction and causes the communications connection to transfer to the local communications device so that the local communications device can also be used to take part in the communications connection. After the communications connection is transferred to the local communications device, the service features offered by the central communications system is available to the user even though the communications connection was originally set up on the portable device. The user can therefore, for example, use the user&#39;s local communications device to initiate a “query” to contact another subscriber within the communications system.  
           [0009]    A further advantage in accordance with an embodiment of the invention is that the user, after answering the communications connection (i.e., the telephone call) on the portable device, can transfer the call to a local communications device that is a line-connected device (for example, a line-connected telephone located at the user&#39;s work space). The transfer to such a line-connected device is regarded by most users as an advantageous feature for numerous reasons. For example, using a line-connected device to service the communications connection avoids electromagnetic interference with the connection, avoids the user experiencing electromagnetic radiation transmitted by the portable device, avoids the user feeling heat generated by the portable device which is perceived as unpleasant, and so forth.  
           [0010]    Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    Embodiments of the invention are explained in more detail below with reference to the drawings, in which:  
         [0012]    [0012]FIG. 1 is a simplified diagram of a system wherein a communications connection is transferred in accordance with an embodiment of the present invention; and  
         [0013]    [0013]FIG. 2 is a simplified diagram of a system after transfer of a communications connection in accordance with an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0014]    [0014]FIG. 1 shows a central communications device  100  coupled to a local communications device  101 . User data is communicated between central communications device  100  and local communications device  101  via a first base channel  102  and a second base channel  103 . Signaling information is communicated between central communications device  100  and local communications device  101  via a signaling channel (not shown).  
         [0015]    In one embodiment, central communications device  100  operates according to a standard known to those of ordinary skill in the art as ISDN (Integrated Services Digital Network) and according to a time-slot-oriented switching principle—often referred to by persons skilled in the art as “Time Division Multiplex”, TDM. Central communications device  100  therefore includes a suitable switching matrix (not shown). Central communications device  100  may, for example, be an ISDN Private Branch exchange (ISDN PBX) device or ISDN switch.  
         [0016]    In the case of an ISDN connection, signaling information exchanged via a “D-channel” (not shown) contains data for connection control, signaling, etc. A further component of the information exchanged between central communications device  100  and the local communications device  101  involves user information, which, for example, contains voice and/or video communications data. In an ISDN communications system, this user information is transmitted via one or more base channels B 1 , B 2  (or “B-channels”).  
         [0017]    A portable device  104  communicates with local communications device  101  via a low-power and short-range wireless link  105 . Two-way data transmission takes place via the wireless link  105  between a first transceiver unit  106  (that is part of or coupled to local communications device  101 ) and a second transceiver unit  107  (that is part of or coupled to portable device  104 ). Wireless link  105  may be a radio link such as, for example, a link that satisfies the well-known Bluetooth standard. Alternatively, the wireless link may be an optical interface such as, for example, an IrDA standard link (Infrared Data Association).  
         [0018]    Portable device  104  may, for example, be a cell phone, a mobile communications terminal, a Personal Digital Assistant (PDA), or other portable communications device. In FIG. 1, portable device  104  is illustrated as a mobile communications terminal. A user carrying portable device  104  is assumed below to be within wireless communication range of local communications terminal  101 .  
         [0019]    Initially, the user and portable device  104  is connected via communications connection  108  and a second communications system  109  to a second subscriber (not shown). Communications connection  108  is, in one embodiment, a GSM telephone communication used to establish communication between the user of portable device  104  and the second subscriber.  
         [0020]    Next, the user of portable device  104  wishes to “transfer” the communications connection  108  from portable device  104  to local communications device  101 . Transfer does not mean that portable device  104  is necessarily disconnected from the communications connection once the “transfer” is made. In this example, transfer means that the local communications device  101  can also be used to take part in the communication connection. Accordingly, the user can, after the transfer, use either portable device  104  or local communications device  104  to take part in communications connection  108 .  
         [0021]    To initiate activation of the transfer, the user issues a command, for example, by actuating a touch-sensitive area on portable device  104 . Alternatively, the user may issue the command by speaking an audible command into a microphone on portable device  104 . Alternatively, the user may issue the command to transfer by providing manual or audible inputs to local communications device  101 . The user&#39;s command causes a transfer instruction to be sent from the portable device  104  to the local communications device  101  via wireless link  105 .  
         [0022]    Once the user of portable device  104  has initiated activation of the transfer, two-way communication is set up via wireless link  105  whereby transceiver unit  106  acts as a wireless talk-listen combination vis-à-vis transceiver unit  107  in accordance with the Bluetooth standard. This allocation of a “profile” of a respective communications end point on a Bluetooth interface is known to the person skilled in the art from the Bluetooth standard—cf., for example, Bluetooth V1.1 Profile Specifications, Version 1.1 dated 22 Feb. 2001, Part K:6: “Headset Profile”.  
         [0023]    Activation of this two-way communication via wireless link  105  may involve second transceiver  107  sending an “identifier” to first transceiver  106 . This identifier may, for example, identify the portable device  104  and may be requested by first transceiver  106 . This “identifier” mechanism can be used to ensure that only an authorized portable device can initiate transfers of communications connection  108 .  
         [0024]    From the perspective of central communications device  100 , first transceiver unit  106  acts like a telephone of a “virtual subscriber.” This virtual subscriber function of first transceiver unit  106  is largely independent of other functionality of local communications device  101 . First transceiver unit  106  therefore provides not only the Bluetooth wireless communication link service, but also a multiplicity of additional services, which are combined into one unit. First transceiver unit  106  may be located outside local communications device  101 , or may be an “adapter” that is connected to and plugged into local communications device  101 .  
         [0025]    Once the two-way wireless communication link  105  is set up, an automatic connection set-up is carried out to establish a connection from first transceiver unit  106  (acting as a virtual subscriber), to central communications device  100 , and back to local communications device  101 . This connection is indicated in the drawing by a dot-dash line  110  between first base channel  102  and second base channel  103 . This automatic connection set-up is set-up using a “hotline to pre-programmed destination” service feature which is a conventional feature of modern communications PBX devices.  
         [0026]    The use of two base channels to exchange user data between local communications device  101  and central communications device  100  is advantageous because control of the communications connection is secured by central communications device  100 . Second base channel  103  is used to feed the user data back to the local communications device  101  so that the call can be handled on local communications device  101 . The user may, for example, switch from using portable device  104  to using a handset (not shown) on local communications device  101  to take part in the call. “De-activation” of the second transceiver unit  107  automatically terminates the connection between first transceiver unit  106  and central communications device  100 .  
         [0027]    In the event that a call is currently in progress on local communications device  101  (for example, second base channel  103  is currently busy), then the communications connection  108  which is to be transferred can be answered as a second call. Alternatively, the communications connection  108  which is to be transferred can be routed by means of the “call divert on busy” service feature to a different destination within a network of several interconnected communications devices (not shown).  
         [0028]    When communications connection  108  is transferred, through-connection of first base channel  102  and second base channel  103  takes place in the switching matrix (now shown) of central communications device  100 . This through-connection is shown by the dot-dash line  110 . The direction arrows do not indicate the data flow direction of the data exchanged in both directions on the first and second base channels  102 ,  103 , but instead indicate a temporal sequence of the switching processes in central communications device  100 .  
         [0029]    [0029]FIG. 2 is a simplified diagram of portable device  104  and local communications device  101 , which are both shown with a handset off-hook, and between which the user data flows. In the example of FIG. 2, the transfer of communications connection  108  has already been carried out. The dot-dash line  111  is a general representation of communications connection  108  after the transfer is complete.  
         [0030]    In the embodiments described above, the use of the Bluetooth standard to realize wireless link  105  is advantageous in that it facilitates use of a standardized infrastructure, which is increasingly used in electronic devices with communications interfaces. Furthermore, because the Bluetooth wireless link uses radio signals in the microwave range, the wireless link is not restricted to the portable device  104  having to be in direct line-of-sight contact with local communications device  101 .  
         [0031]    Although the present invention has been described in connection with certain specific embodiments, the present invention is not limited thereto. Various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.