Abstract:
Systems and methods for allowing transmission of tones by a push-to-talk (PTT) communication station are provided. The communication station can decouple the PTT button of the PTT communication station, allowing the transmission of the tones without actuating the PTT button. The decoupling can be performed in response to receipt of an unsolicited floor grant message. The communication station can also receive an input selection and automatically transmit a floor request message, a tone corresponding to the input selection and a floor release message.

Description:
BACKGROUND OF THE INVENTION 
     Wireless communication networks typically provide a number of different services, such a voice and data communication services. Most wireless communication networks typically offer a single type of voice communication service, interconnect voice communication services (also referred to as circuit-switched voice communication services). Interconnect voice communication services provide a full-duplex communication between two communication endpoints. 
     Another type of voice communication service is push-to-talk voice communication service (also referred to as dispatch communication service), which involves a half-duplex communication between two or more communication endpoints, such as push-to-talk communication stations. Thus, a push-to-talk call requires floor control to ensure that only one endpoint has permission to talk at any particular time during the call. Push-to-talk systems typically implement floor control by having communication stations send a floor request message when the push-to-talk button is depressed and a floor release message when the push-to-talk button is released. When none of the communication stations of a push-to-talk call currently controls the floor, any of the communication stations can request the floor by depressing the push-to-talk button. While the push-to-talk button is depressed the user can speak into the communication station and the voice is transmitted to other communication stations of the push-to-talk call. When the push-to-talk button is released a floor release message is transmitted by the communication station. 
     SUMMARY OF THE INVENTION 
     Exemplary embodiments of the present invention provide systems and methods for transmitting tones, such as dual tone multiple frequency (DTMF) tones, during a push-to-talk call. 
     In accordance with one aspect of the present invention systems and methods are provided that involve receiving, by a push-to-talk (PTT) communication station, a floor grant message, and determining, based on the floor grant message, to decouple a PTT button of the PTT communication station. The systems and methods also involve receiving, by the PTT communication station, first and second input selections, and transmitting first and second tones that respectively correspond to the first and second input selections. The first and second tones are transmitted independent of an actuation of the PTT button. 
     In accordance with another aspect of the present invention systems and methods involve transmitting, by an application server to a push-to-talk (PTT) communication station, voice information, and transmitting, by the application server to a PTT server, a message related to floor control. The systems and methods also involve receiving, by the application server from the PTT communication station, a first and second tone, and determining, by the application server, a selection corresponding to the first and second tones that is responsive to an option provided by the voice information. 
     In accordance with another aspect of the present invention, systems and methods involve receiving, by a push-to-talk (PTT) communication station, an input selection. In response to the input selection the PTT communication station sequentially transmits a floor request message to a PTT server, a tone corresponding to the input selection to an application server, and a floor release message to the PTT server. 
     Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         FIG. 1A  is a block diagram of an exemplary PTT communication station in accordance with the present invention; 
         FIG. 1B  is a block diagram of an exemplary application server in accordance with the present invention; 
         FIGS. 2A-2C  are call flow diagrams in accordance with one aspect of the present invention; 
         FIG. 3  is a call flow diagram in accordance with another aspect of the present invention; and 
         FIGS. 4A and 4B  are call flow diagrams in accordance with yet another aspect of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Exemplary embodiments of the present invention provide systems and methods of transmitting tones in a PTT call. Although exemplary embodiments are described below in connection with a PTT call between a PTT communication station and an application server, the present invention is not so limited. For example, the present invention can also be employed for transmitting tones between two or more PTT communication stations. 
       FIG. 1A  is a block diagram of an exemplary PTT communication station in accordance with the present invention. PTT communication station  105  includes processor  110  coupled to memory  120  and PTT button  125 . Processor  110  includes logic  112 - 116 , which will be described in more detail below in connection with  FIGS. 2A through 4B . Processor  110  can be a field programmable gate array (FPGA), application specific integrated circuit (ASIC) and/or a microprocessor. When processor  110  is a microprocessor, logic  112 - 116  can be processor-executable code loaded from memory  120 . 
       FIG. 1B  is a block diagram of an exemplary application server in accordance with the present invention. Application server  150  includes memory  155  coupled to processor  160 . Processor  160  includes logic  162 - 168 , which will be described in more detail below in connection with  FIGS. 2A-4B . Processor  160  can be any type of processor, including a field programmable gate array (FPGA), application specific integrated circuit (ASIC) and/or microprocessor. When processor  160  is a microprocessor, logic  162 - 168  can be processor-executable code loaded from memory  155 . 
       FIGS. 2A-2C  are call flow diagrams in accordance with one aspect of the present invention. Initially, when access to application server  150  is desired, a communication address of the application server is entered into communication station  105  and PTT button  125  is actuated (i.e., depressed and released). In response, communication station  105  sends an INVITE message to PTT server  130  (step  202 ), which then forwards the INVITE message to application server  150  (step  204 ). Application server  150  replies with an OK message to confirm that the application server is available to participate in the PTT call (step  206 ). PTT server  130  forwards the OK message to communications station  105  (step  208 ), which then replies with an ACK message (step  210 ). PTT server  130  then forwards an ACK message to application server  150  (step  212 ), which establishes a PTT call between communication station  105  and application server  150 . 
     Communication station  105  can then request the floor of the established call by depressing PTT button  125  (step  213 ). Communication station  105  then sends a floor request message to PTT server  130  (step  214 ), which replies with a floor granted message (step  216 ). PTT server  130  notifies application server  150  that the floor has been granted to another communication endpoint by sending a floor taken message to application server  150  (step  218 ). Communication station  105 , having the floor and having the PTT button still depressed, can send voice information to application server  150  (step  220 ). The voice information can be a request for a service provided by application server  150 . For example, application server  150  can provide a number of different services, such as weather, news, horoscopes, sports scores and/or the like. Accordingly, the voice information can be a request for the weather service. 
     When the PTT button  125  is released (step  221 ), communication station  105  sends a floor release message to PTT server  130  (step  222 ). PTT server  130  then sends floor idle messages to communication station  105  and application server  150  to notify the communication endpoints that the floor is open (steps  224  and  226 ). 
     Application server  150  can then send a floor request message to PTT server  130  (step  228 ), which then sends a floor granted message to application server  150  (step  230 ) and a floor taken message to communication station  105  (step  232 ). Logic  162  of processor  160  of application server  150  then sends voice information to communication station  105  (step  234 ). Continuing with the example above, the voice information can be a request for the communication station  105  to provide a zip code for desired the weather information. 
     When application server  150  has completed sending the voice information, logic  164  sends a floor release message indicating that an unsolicited floor grant should be made to communication station  105  (step  236 ). The floor release message identifies the communication station, that the media is dual tone multiple frequency (DTMF) and a media release identifier, which in this case is the “#” symbol. In response to receiving the floor release message, PTT server  130  sends floor idle messages to communication station  105  and application server  150  (steps  238  and  240 ). 
     PTT server  130  then sends an unsolicited floor grant notification message to communication station  105  (step  242 ). The floor grant is unsolicited because communication station  105  did not send a floor request to PTT server  130 . The unsolicited grant notification message identifies the media type as DTMF and the release identifier, and this message is received by logic  112 . 
     Identifying the unsolicited grant notification message, logic  112  notifies logic  114  that the PTT button should decoupled (step  244 ). The decoupling of the PTT button allows the transmission of media from communication station  105  to application server  150  without requiring actuation of the PTT button  125 , which in this case are DTMF tones. Specifically, in response to actuation of the number key “1”, logic  116  sends a corresponding DTMF tone to application server  150  (step  248 ). Similarly, in response to actuation of number key “2”, logic  116  sends a DTMF tone to application server  150  (step  250 ). Actuation of number key “3”, logic  116  sends a DTMF tone to application server  150  (step  254 ). Although not illustrated, communication station  105  can send two additional tones to provide a total of five tones corresponding to a zip code. When key “#” is actuated, logic  116  transmits a corresponding DTMF tone to application server  150 . Logic  114  recognizes the “#” as the release indicator, and accordingly sends a floor release message to PTT server  130  (step  256 ). In response to receiving this message, PTT server  130  sends floor idle messages to communication station  105  and application server  150  (steps  258  and  260 ). 
     Although not illustrated in  FIGS. 2A-2C , logic  166  of application server  150  receives each of the tones and passes the received tones to logic  168 . Logic  168  then determines a selection corresponding to the received tones (step  262 ), sends a floor request message (step  264 ), receives a floor granted message step  266 ) and then sends voice information corresponding to the selection (step  270 ). Returning again to the example above, the selection would correspond to a zip code of the digits entered by communication station  105 . As illustrated in  FIG. 2C , PTT server  130  sends a floor taken message to communication station  105  (step  268 ) after sending the floor granted message to application server  150 . 
       FIG. 3  is a call flow diagram in accordance with another aspect of the present invention. Steps  202 - 232  described above in connection with  FIGS. 2A and 2B  will be performed similarly for the method of  FIG. 3 , and accordingly these steps will not be described in detail again. After application server  150  completes the sending of voice to communication station  105  (step  234 ), the application server sends a conventional floor release message to PTT server  130  (step  237 ). In response, PTT server  130  sends floor idle messages to communication station  105  and application server  150  (steps  238  and  240 ). Application server  150  then sends an unsolicited floor grant request message to PTT server  130  (step  241 ), which then sends an unsolicited floor grant notification message to communication station  105  (step  242 ). The unsolicited floor grant request message identifies communication station  105 , the media type and the media release key, and the notification message identifies the media type and the media release key. 
     The remainder of the method of  FIG. 3  operates in a similar manner to that of steps  244  through  260  described above in connection with  FIGS. 2B and 2C , and will not be described in more detail again. The distinction between the methods of  FIGS. 2A-2C  and that of  FIG. 3  is that in the method of  FIGS. 2A-2C  the floor release message (step  236 ) includes the request for granting the unsolicited floor grant, the media type and the media release key, whereas in the method of  FIG. 3  this information is sent in a message separate from the floor release message. 
       FIGS. 4A and 4B  are call flow diagrams in accordance with yet another aspect of the present invention. Steps  202 - 232  operate in a similar manner to that described above in connection with  FIG. 2A  and  FIG. 2B  and these steps will not be described in detail again. After application server  150  finishes sending the voice to communication station  105  (step  234 ), the application server sends a floor release message to PTT server  130  (step  237 ). PTT server  130  then sends floor idle messages to communication station  105  and application server  150  (steps  238  and  240 ). 
     When communication station  105  detects a depression of a number on the key pad, in this case number “1”, logic  114  controls the communication station to send a floor request message to PTT server  130  (step  302 ), which responds with a floor granted message (step  304 ). PTT server  130  then sends a floor taken message to application server  150  (step  306 ). Logic  116  then sends a DTMF tone corresponding to the number “1” to application server  150  (step  308 ), and a logic  114  sends a floor release message to PTT server  130  (step  310 ). PTT server  130  then sends floor idle messages to communication station  105  and application server  150  (steps  312  and  314 ). 
     The decoupling of the PTT button  125  in the method of  FIGS. 4A and 4B  does not involve an unsolicited floor request, but instead is based merely upon depression of a key on the key pad of the communication station, which then requests the floor, sends the corresponding tone and then sends a floor release message. Accordingly, for each subsequent depression of a number on the key pad, for example key pad depression key “2” steps  316  through  326  operate in a similar manner to that described above in connection with steps  302  through  314 . In the method of  FIGS. 4A and 4B  the user of communication station  105  needs to notify application server  150  that the selection has been completed by sending a selection completed indication symbol, which in this case is the “#” key. This transmission involves steps  330  through  342 , which operate in a similar manner to that described above in connection with steps  302  through  314 . 
     Although the methods are described above with communication station  105  initially sending voice to application server  150 , this is merely exemplary and not necessary. For example, communication station  105  can enter an address for application server  150  and then actuate (i.e., depress and release) PTT button  125  in order to establish the PTT call. Application server  150  could then request the floor and send voice information. 
     It should be recognized that the signaling illustrated in the figures is merely exemplary and that not all of the signaling is necessary for the present invention and such signaling should not limit the scope of the claims beyond their express language. Furthermore, the present invention can be practiced using similar messaging, but with different message names. The discussion above referred to a key pad, which should be understood as broadly representing any type of input mechanism, including physical keys, soft keys and/or keys on a touch screen. 
     The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.