Method and apparatus to facilitate a transparent service option transition

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DESCRIPTION

Procedure and apparatus to facilitate a seamless transition of service options.

Background

I. Field

The present invention pertains generally to the field of telephone communications, and more specifically to the provision of an effective method and apparatus to allow a seamless transition of service options between at least two communication devices.

II. Background

The field of wireless communications encompasses many applications including cordless telephones, paging devices, terrestrial wireless communication systems, and satellite communication systems. The use of terrestrial communication systems has become trivial as consumers around the world enjoy the benefits of cheap mobile communications.

Cellular technology has evolved over the years, starting from an analog modulation scheme commonly known as AMPS (Advanced Mobile Phone System). Introduced by AT&T in 1983, the AMPS became the most widely deployed modular system in the United States.

Digital modulation schemes soon followed. Examples of such modulation schemes include Global System for Mobile (GSM), Time Division Multiple Access (TDMA), and Code Division Multiple Access (CDMA) communications. Digital communication systems offer advantages over AMPS, including a higher degree of voice quality.

Along with digital telephones, wireless data communications have proven to be increasingly important. With the success of the Internet, there has been a need to provide mobile users with the ability to send and receive digital data communications. At present, the digital communication systems mentioned above offer various techniques to allow data communication to take place. For example, it is now common for wireless phones to receive stock quotes, email, and new items.

In an extension of data communications, techniques are currently available for converting audio information, such as human speech, into data packets suitable for transmission over a data network, such as the Internet. Audio information can be converted into data packets and transmitted over the air using a data service offered by a wireless service provider. Data service is often an addition to the standard voice service offered by service providers. This kind of voice-over-data can be useful for applications such as the provision of encrypted voice service for military purposes, for example.

In a communication system that provides both voice and data services, it would be desirable to allow users to transition between voice communications and data communications while the users are actively engaged in a communication. For example, it would be advantageous for two users connected via a conventional voice telephone call to transition to the data service option that supports a secure mode of voice or data communications.

Attention is also drawn to document US-A-5,592,538, which describes a telecommunication device that allows mixed voice and data communications during a single telephone call. A device freely switches between two-way voice communications and two-way data communications, as required by the data to be communicated. Dynamic switching between voice communication and data communication is established so that voice communication is minimally interrupted. The data communication used by the device includes the creation, transmission, reception, storage, retrieval, display and use of messages such as address and telephone number records. A full interactive voice and data (IVD) system automatically performs data communication between subscriber IVD systems or between a subscriber IVD system and a host IVD system. Additionally, in conjunction with the standard IVR, a full IVR / IVD system automatically performs data communication with subscriber IVD systems, and IVR voice communications with non-subscriber IVD systems.

Attention is drawn to document US-A-5,953,505, which describes a communication terminal that includes a memory for storing various types of information related to a communication partner, for example, information representing the partner's functions. of communication and that identify the information for the identification of the communication partner. The terminal can discriminate a communication partner on the basis of both a signal transmitted from the communication partner transmitted during a communication operation, and identification information stored in a memory, and can display the various information related to the communication partner. according to discrimination.

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Summary of the invention

In accordance with the present invention, there is provided an apparatus for facilitating a transparent service option transition, as defined in claim 1, and a method for facilitating a transparent service option transition, as defined in claim 6. Embodiments of the invention have been described in the dependent claims.

The present invention is directed to a method and apparatus for allowing a seamless transition of service option between at least two communication devices. The invention is applicable to any communication system employing two or more service options. Examples of service options include voice communications, asynchronous data communications, and packet data communications.

In one embodiment, a communication is established between two wireless communication devices using one of the available service options, eg, voice communications. At some point in this initial communication, one or both parties involved in the communication wishes to continue the initial communication in a service option other than the present service option. For example, at some point during a voice communication, one or both parties wish to switch from the current voice communication service option to an asynchronous data service option to use a secure mode of communication employing cryptographic techniques.

In one embodiment, one or both parties involved in the initial communication begins a transition to the second service option by pressing a previously designated key on the wireless communication device.

Pressing the previously designated key triggers a series of actions between the two communication devices. First, information is exchanged between the two wireless communication devices. The initial communication between the parties is then terminated. A second communication is then established using a second service option already agreed upon, initiated by one of the parties.

In one embodiment, during call initialization in the second service option, the non-initiating party receives initialization information from the initiating party. As part of the initialization process, the non-initiating party determines the identity of the initiating party by authenticating the initiating party through one of several techniques, such as using a caller ID function. The non-initiating party can choose to accept communications only from the initiating party based on the identity of the initiating party. This is done to prevent a third party from initiating a communication with the non-initiating party before the initiating party has a chance to establish the second communication.

Brief description of the drawings

Figure 1 illustrates a wireless terrestrial communication system, into which various embodiments of the present invention have been incorporated;

Figure 2 illustrates a functional block diagram of a wireless communication device as used in one embodiment of the present invention;

Figure 3 illustrates a flow chart illustrating a procedure to facilitate a transparent service option transition;

Figures 4a and 4b are flow charts illustrating a procedure to facilitate a transparent service option when two wireless communication devices initiate an action to carry out a transition to the second service option;

Figure 5 is a flow chart illustrating a procedure to facilitate the transparent service option when an identification code corresponding to another wireless communication device is known;

Figure 6 is a flow chart illustrating an alternative procedure for facilitating a transparent service option when an identification code corresponding to another wireless communication device is known;

Figure 7 is a flow chart illustrating an embodiment of the present invention to successfully perform a communication transition from a first service option to a second service option when two wireless communication devices each create , who have not initiated the initial communication, and Figure 8 is a flow chart illustrating an embodiment of the present invention for successfully transitioning a communication from a first service option to a second service option when two wireless communication devices believe that they have both initiated the communication. initial communication.

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Detailed description

The embodiments described here will be described with respect to a wireless terrestrial communication system that has at least two service options available to users. It will be understood that the described embodiments can be used in other communication systems as well, such as in a satellite communication system or in a wired communication system (eg, the Public Switched Telephone Network). For example, the embodiments described herein could be used in communications between a cordless telephone and a corded telephone, between a first cordless telephone and a second cordless telephone, or between two corded telephones.

Figure 1 illustrates a wireless terrestrial communication system 100, into which various embodiments of the present invention have been incorporated. Wireless communication devices 102 and 104 (WCDs) communicate with wireless base station transceivers 106, 108 and / or 110 (BTSs) using one or more well-known air interfaces, such as code division multiple access (CDMA). ), time division multiple access (TDMA), global system for mobile communications (GSM), or others. The WCDs 102 and 104 have been depicted in Figure 1 comprising cellular telephones, although it will be understood that the WCDs 102 and 104 could alternatively comprise a variety of electronic devices, such as a camera, a video camera, a laptop or fixed computer, a data collection device, a combination of the aforementioned, or other well known electronic devices.

Communications from the WCDs can be routed to devices outside the communication system 100 (such as telephones or data modems) through a mobile switching center 114 (MSC). The MSC 114 routes communications to those other devices either through the public switched telephone network (PSTN) 116 or through a data network 118. Satellite access 120 is used to connect satellite devices, such as telephones or data modems, generally to a PSTN. The information is subsequently received by data device 122 or modem 124, as the case may be.

Each of the devices described above is generally capable of communicating in more than one mode of operation, for example, communicating in voice mode and in data mode. Voice mode communications typically comprise transmitting human speech from one device to another, such as between a WCD and a corded telephone, or from a first WCD to a second WCD. Data communications generally comprise the transmission of data, including applications such as facsimile transmission, email, internet access, audio and video pipeline applications, and voice-over-data applications. Data communications today typically comprise one of two types: circuit-switched or packet-switched data communications.

Each of the modes just mentioned is commonly referred to as "service options" by those skilled in the art. Examples of service options include voice service options and data service options. Two data service options used in cellular communications are defined in the Interim Standard IS-707A entitled "Data service options for wide-spectrum bandwidth systems", and include an asynchronous data service option, and a synchronous data service option. Other service options may alternatively be used in the communication system 100.

The synchronous data service option defined in the Interim Standard IS-707A entitled “Data service options for wide-spectrum bandwidth systems” consists of a packet-switched data service. In such packet data communications, the information is formed into discrete units, or packets, each packet comprising information relating to an address corresponding to a destination device for which the data packets are intended. An example of a data address is an Internet Protocol address, or IP address. A typical IP address comprises four fields, each field being in the range of 0 to 255, uniquely identifying the target device, which is connected to a data network such as the Internet. Data packets are transmitted over the data network, typically over a number of different paths, and may arrive in a different order than they were originally sent.

The asynchronous data service option, defined in the Interim Standard IS-707A entitled “Data service options for broad spectrum bandwidth systems”, consists of a circuit-switched data service. A common example of circuit switched data communications is a facsimile machine transmitting information over the PSTN 116 to a second facsimile machine. The first facsimile machine establishes a dedicated connection over the PSTN 116 with the second facsimile machine. Once the connection has been established, the data is exchanged between the facsimile machines on the dedicated circuit provided by the PSTN 116. Note that in asynchronous communications, the transmitted information does not generally contain information identifying the destination device.

As explained above, the WCDs 102 and 104 are capable of transmitting and receiving both voice and data communications. In one embodiment, the data communications comprise encrypted voice communications. Encrypted voice communications can be used to prevent unauthorized listeners from intercepting and understanding telephone conversations. In this embodiment, the audio information is digitized and encrypted, whereby the resulting information is transmitted using one of the available data service options, including other data protocols in addition to asynchronous and synchronous data communications, described in what foregoing.

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Often times, it becomes necessary to transition from a communication that initially uses a first service option to a second service option. For example, a user of a first WCD may initiate communication with a user of a second WCD using a voice service option commonly used in wireless communication systems to transmit voice communications. At some point during the initial voice communication, one or both users may decide to continue the conversation in an encrypted communication mode. In this embodiment, secure voice communications are available to the two users using an asynchronous data service. It would be desirable to transition the communication from the first service option (voice service option) to the second service option (asynchronous data service option) in a way that is transparent to both users.

The present invention is directed to the realization of a service option transition between two communication devices. Ideally, the procedure and apparatus for doing this is transparent to users, that is, the transition results in minimal disruption to the initial communication between the parties.

Figure 2 illustrates a functional block diagram of the WCD 102 or WCD 104 as used in one embodiment of the present invention. Again, it should be understood that the components shown in Figure 2 are not limited to use in wireless communication devices, but could be implemented in other devices, such as a corded telephone. In this embodiment, the WCD 102 is a wireless telephone capable of communicating using more than one service option. Of course, the WCD 102 could alternatively comprise a wired or wireless modem, used in conjunction with any number of electronic devices, such as a laptop, a still camera, a video camera, or an electronic meter (such as a pressure gauge. , a power meter, a flow meter, etc.)

A user of the WCD 102 may want to communicate with another WCD, for example the WCD 104 or the modem 124, using a first service option, such as a voice service option. The various service options available for the WCD 102 are enforced by a service provider of the communication system 100. To initiate a communication, the user generally enters an identification code corresponding to WCD 104 into WCD 102, using user interface 200. Interface 200 typically comprises a keyboard and display, although other interfaces may be used where appropriate, such as a voice-activated interface, for example. The identification code typically comprises a telephone number, although any alphanumeric combination that uniquely identifies the WCD 104 could alternatively be used. Additionally, each WCD of the communication system 100 could have a unique identification code for each service option supported by the communication system. For example, the WCD 104 can be uniquely identified by a simple phone number during a voice service option, and by another phone number for use in placing an asynchronous data call using the voice service option. asynchronous data. Or the WCD 104 can be identified by a data address such as an Internet Protocol (IP) address.

In either case, after the user of the WCD 102 initiates communication with the WCD 104, the processor 202 generates any instructions necessary to establish a communication with the WCD 104 using well-known techniques appropriate to the communication system 100. Often times this includes sending one or more messages, sometimes known as a source message, to one or more base station transceivers 106, 108 and / or 110 (BTSs). Such BTSs are well known in the art for sending and receiving communications between the WCDs and a base station controller 112 (BSC), which is also known in the state of the art. In this example, it will be assumed that the WCD 102 is in communication with the BTS 106.

The source message (s) instructs the communication system 100 where to route the intended communication (in this case, to the WCD 104) by including the identification code corresponding to the WCD 104. In another embodiment , each WCD is assigned an identification code for each service option supported by the communication system 100. In this embodiment, the source message includes the identification code corresponding to the WCD 102 using the voice service option. In any case, the source message also informs the communication system 100 of the identity of the requesting WCD (in this case, the WCD 102), and also of the type of service option desired (in this case, the service option of voice). Again, if the WCD 102 has been assigned an identification code for each supported service option, then the source message will include the identification code corresponding to the WCD 102 using the voice service option. Additional information may also be exchanged between communication system 100 and WCD 104.

The originating message is received by BTS 106, and sent to BSC 112. From there, the request is generally sent to mobile switching center 114 (MSC). MSC 114 acts as a central point for call routing, and includes other essential functions for communication system 100, such as billing. In this case, an indication of the request to initiate communications is routed back to BSC 112, then to BTS 110, and transmitted to WCD 104, advising WCD 104 that a voice service communication is available. The request to WCD 104 will generally comprise an identification of the requesting device, in this case WCD 102. Typically, this is provided by a Caller ID function, or Caller ID for brevity. Caller ID is a widely used protocol to provide an identification of a requesting device (in this case the WCD 102) to a receiving device (in this case, the WCD 104). Of course the caller ID is not the only protocol that could be used to provide identifying information. Alternatively, any other technique known to those skilled in the art could be used.

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In either case, the request is received by the WCD 104, and the request is accepted by a user of the WCD 104 by taking appropriate actions, such as depressing a key located on the wCd 104. The two users can then initiate communication from each other. voice using the voice service option provided by the communication system 100.

At some point during the conversation, one or both users may decide that they want to continue communication using an alternative communication service option, such as the asynchronous data service option that offers both secure and "clear" voice transmissions, or a Synchronous data service option offering both secure and “clear” data transmissions. The term "clear" is used to indicate unsecured or unencrypted communications.

In an embodiment where each WCD has been assigned an identification code corresponding to each service option supported by the communication system 100, the WCD 102 can initiate communication with the WCD 104 in the voice service option, due to simply because the WCD 102 does not know the identification code assigned to the WCD 104 using the service option. In this case, the WCD 102 can initiate communications using the voice service option, and immediately begin the transition process to the second service option without any actual voice communication between the users.

Either user can initiate a service option transition. For discussion purposes, WCD 102 is supposed to initiate the transition. The user of the WCD 102 initiates the transition by entering a predetermined command into the WCD 102 using the user interface 200, for example by pressing a pre-designated key for a predetermined period of time. The type of service option to transition to can also be chosen by the user, predetermined, or negotiated between wCd 102 and WCD 104. Processor 202 receives the command and generates one or more messages for transmission to BTS 106 using transmitter 204.

In one embodiment, prior to processor 202 generating the messages necessary to begin the service option transition, processor 202 checks to determine if the user of WCD 102 has "identified" to WCD 102 as a secure user prior to continue with service option transition. In this embodiment, a unique passcode is pre-assigned to the WCD 102, which must be provided by the user at some point prior to making, or receiving, a secure call. Processor 202 generally determines the status of the passcode by checking memory 206. An indication of successful identification will be stored in memory 206 if the user has previously been identified.

If the user has not previously identified in the WCD 102, the processor 202 prompts the user to enter the assigned passcode. Upon entry, processor 202 determines whether the entered passcode matches the passcode assigned to WCD 202. This can be done by accessing memory 206. Memory 206 comprises an electronic memory, well known to those skilled in the art. subject. Typically, memory 206 comprises random access memory or flash memory. Processor 202 compares the stored passcode with the passcode entered by the user. If a match is determined, processor 202 proceeds with the service option transition. Alternatively, the stored passcode could be kept in a remote memory from WCD 102, such as at BSC 112, mSc 114, or anywhere, such as a Visitor Location Record (VLR) or a Guest Record. Home Location (HLR) (neither of which has been depicted). VLRs and HLRs are well known in the art to support wireless communication systems. Each database (HLR or VLR) comprises information pertaining to the various WCDs that operate within the communication system 100, or the tracking WCDs that operate in other communication systems. In this embodiment, processor 202 generates a question to remote memory that stores the passcode information, and transmits the question using transmitter 204. In general, a processor associated with the remote memory determines whether the passcode entered by the user matches the passcode stored in the remote memory. A message is transmitted to the WCD 102 indicating the result. If a match has been determined, processor 202 continues with the service option transition.

Processor 202 begins the service option transition by transmitting a transition message to WCD 104, requesting an identification code that uniquely identifies WCD 104. In another embodiment, the requested identification code comprises an identification code associated with the WCD 104 for use in the second service option. In still another embodiment, the WCD 102 transmits an identification code that uniquely identifies the WCD 102 for use in the second service option. Upon receipt of the transition message, the WCD 104 generates and transmits the requested identification code. Again, in an embodiment where each WCD has been assigned a separate identification code for each service option, the WCD 104 transmits the identification code associated with the second service option.

In one embodiment, the information transmitted between the WCDs during this time (i.e., the transmission of the identification code (s)), is modulated by a dual-tone multi-frequency (DTMF) module 208, and transmitted within band. In another embodiment, the DTMF tones are transmitted out of band. Additionally, in another embodiment, the messages sent between the WCDs used to perform the service transition (ie, the transition messages, acknowledgments, identification codes, etc.), are all transmitted using in-band DTMF transmission. These tones are not generally heard by each user. The DTMF module 208 is responsible for modulating the information coming from the processor 202 into DTMF tones, and also for demodulating the

ES 2 314 031 T3 DTMF tones received by receiver 210. It should be understood that the functionality of DTMF module 208 could alternatively be performed by processor 202 in conjunction with a series of computer-executable instructions stored in memory 206. It should also be understood that the information transmitted between WCDs could alternatively be performed using a different modulation scheme than using in-band DTMF modulation, such as Frequency Shift Keying (FSK) or data transmission, which are well known in the world. telecommunications technique.

DTMF tones are generated at two specific frequencies, combined to form a tone that is very difficult to duplicate with the human voice. DTMF minimizes the possibility of accidental detection of voice as transmission occurs, and can therefore be transmitted as an audio signal on the same channel as voice in a communication system 100. Standard WCDs are equipped with the ability to generate DTMF tones for a variety of transmission purposes, such as feature activation and voicemail.

DTMF module 208 receives the identification code from processor 202, and converts the identification code into a series of DTMF tones, which are then transmitted in-band. Similarly, a DTMF module converts the identification code from WCD 104 into DTMF tones that are transmitted to WCD 102 and received by receiver 210. The received DTMF tones are routed to DTMF module 208 and demodulated, producing a digital signal that is used by processor 202. Alternatively, the information identifying each WCD could be stored within a memory, such as memory 206, so that the DTMF module 208 does not have to rely on the information supplied by the processor 202 each time a transition is desired.

WCD 102 receives the identification code from WCD 104, and stores it in memory 206. WCD 102 then terminates the initial voice communication. In general, this includes generating a termination message from processor 202, and transmitting the message to BTS 106. The termination message is sent to BSC 112 and / or MSC 114 so that the initial communication can be terminated. This process is well known in the art. In general, the termination is also made known to WCD 104. In one embodiment, when the communication has ended, the WCD 104 starts an elapsed time timer to determine the amount of time elapsed from the termination of the communication until a next communication is received.

After the initial communication has ended, the WCD 102 or WCD 104 initiates a second communication with the other WCD using a second service option, in this case, the asynchronous data service option. In another embodiment, the second communication is initiated by a predetermined protocol, such that the WCD that initiated the initial communication begins the second communication. Of course, other variations are possible. Assuming the WCD 102 initiates the second communication, the processor 202 generates one or more messages to initiate the communication. This information, referred to in its entirety as the originating message, generally comprises the identification code received from the WCD 104 and stored in the memory 206, used to inform the BSC 112 and / or the MSC 114 with which to route the communication (ie i.e. WCD 104). In one embodiment, the source message also comprises the identification code associated with the WCD 102, both for use in the first service option and the second service option.

The originating message is received by the BTS 106 and sent to the BSC 112 and / or the MSC 114. A message is generated by the BTS 110 and transmitted to the WCD 104 indicating the availability of a communication and an indication of what type of option service has materialized communication. The message may also comprise the identification code associated with the WCD 102, or the identification code may be transmitted in a later message.

In one embodiment, the WCD 104 receives the message using the receiver 210, and the processor 202 determines whether the identification code contained in the original message matches the identification code that was transmitted by the WCD 104 in the initial communication. If a match is found, the WCD 104 accepts the communication using techniques well known in practice. In this case, it results in asynchronous communication between the WCD 102 and the WCD 104.

If no match is found (indicating that another WCD is attempting communications with the WCD 104), the WCD 104 will only accept the communication if a predetermined period of time has elapsed since the termination of the previous communication with the WCD 102. According to As mentioned above, the WCD 104 uses an interval timer to determine if the predetermined period of time has elapsed. If the predetermined period of time has not elapsed, it indicates that the wCd 104 is still waiting to be contacted by the WCD to complete the service option transition. Therefore, the interval timer is used to ensure continuity of communications between WCD 102 and WCD 104 during the transition between the first communication using the first service option, and the second communication using the second service option. service.

In another embodiment, the identification code associated with the WCD 102 is ignored (or not contained within the source message). In this case, the WCD 104 simply accepts the communication using techniques well known in practice to complete a communication using the specified service option.

It should be understood that the features just described with respect to WCD 102 and WCD 104 are found in each device. That is, the processes of transmitting an identification code to another WCD, ending the initial communication, initiating the second communication that uses the second service option,

ES 2 314 031 T3 receiving notification of the availability of the second communication, processing the identity of the WCD initiating the second communication, and accepting or rejecting the second communication, are all within a single WCD. Therefore, a number of different scenarios are possible.

In a first scenario, WCD 102 and WCD 104 are engaged in an initial communication using a first service option. The WCD 102 initiates the service option transition by sending its identification code, ending the initial communication, and initiating the second communication.

In a second scenario, WCD 102 and WCD 104 are engaged in initial communication using a first service option. The WCD 104 initiates the service option transition by sending its identification code, ending the initial communication, and initiating the second communication.

In a third scenario, WCD 102 and WCD 104 are engaged in initial communication using a first service option. Both WCD 102 and WCD 104 initiate the service option transition by sending their respective identification codes.

The three previous scenarios could be modified by a single WCD transmitting a respective identification code. An identification code is only needed for situations where identification of the incoming communication is not required (that is, when the interval timer is not used). In another embodiment, no identification codes are transmitted if one of the WCDs already knows the identification of the other WCD. This will be discussed in what follows.

Figure 3 illustrates a procedure to facilitate a transparent service option transition. In this example, the WCD 102 initiates the actions necessary for the service option transition. It should be understood that both WCD 102 and WCD 104 can initiate this action.

Referring now to Figure 3, an initial communication is established between the WCD 102 and the WCD 104 using a first service option in step 300. At a later time, the WCD 102 initiates a transition to a second service option, shown at step 302. Typically, this comprises a user of the WCD 102 pressing a key on the WCD 102.

In step 304, in response to the command to initiate a service option transition, processor 202 transmits a transition message to WCD 102. The transition message is received by WCD 104 and, in response, WCD 104 transmits its identification code to WCD 102, as shown in step 306. In step 308, the identification code corresponding to WCD 104 is received by WCD 102.

In step 310, the WCD 102 terminates the initial communication by sending a termination message that instructs the BSC 112 / mSc 114 to terminate the initial communication as is well known in the art. WCD 104 is generally notified of termination.

In step 312, the WCD 102 initiates a second communication using a second service option by transmitting one or more messages, collectively known as the source message. The source message specifies the type of service option desired, the identification code received from WCD 104 indicating where to route the second communication, and optionally, the corresponding identification code to WCD 102. In one embodiment, the second communication must start generally within a predetermined period of time from the termination of the first communication.

The WCD 104 is alerted regarding the availability of the second communication by the BTS 106 using techniques well known in practice, and responds to the notification by the BTS 106, thereby establishing the second communication, as shown in step 314 . In one embodiment, prior to accepting the communication, the WCD 104 determines whether the second communication originated with the WCD 102 by evaluating the identification code transmitted by the WCD 102 along with the warning from the BTS 106. If the communication code identification corresponds to a WCD other than WCD 102, the communication is rejected by the WCD 102 if a predetermined period of time has not expired since the termination of the initial communication. If the identification code corresponds to wCd 102, then the WCD 104 accepts the communication using techniques well known in practice.

Figures 4a and 4b are flowcharts illustrating a procedure to facilitate a transparent service option when both WCDs initiate a transition action to the second service option. If not handled beneficially, the transmission that occurs could be processed by each WCD as unexpected and thus cause erroneous messages between the WCDs, causing a transition to failure.

In step 400, a communication is initiated between a first WCD and a second WCD using a first service option, the first WCD having initiated communication, in this example. Additionally, the first service option comprises a voice service option, although it should be understood that the first service option could alternatively comprise a synchronous data service option, an asynchronous data service option, or some other service option offered. by the wireless service provider.

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In step 402, the users of the first and second WCDs agree to transition from communication to a second service option, in this example, secure data communication using an asynchronous data service option offered by the wireless service provider. At step 404, both users initiate the transition, generally by pressing a key located on their respective WCDs.

In step 406, a transition message is transmitted by each WCD in response to the command to initiate a service option transition. A first countdown timer is also started on each WCD. The first countdown timer is used to determine when the other WCD has responded to the transition message. If a return message is not received within a predetermined amount of time, an error is declared, and the user is generally notified via interface 200. The transition message informs the other WCD that a transition to a one is desired. second default service option. In another embodiment, the transition message further comprises information identifying the service option to transition to, or an identification code corresponding to the transmitting WCD.

In step 408, each WCD receives the transition message, and in response to the transition message determines whether to send an acknowledgment message in response to receipt of the transition message, or whether to send an identification code to the other. WCD, as shown in step 410. In one embodiment, this decision is based on whether or not the WCD initiated the initial communication. If the current communication (the first WCD in this example) initiated, an acknowledgment message is sent from the first WCD to the second WCD, as shown in step 410, acknowledging receipt of the transition message. In step 412, the first countdown timer of the first WCD is canceled because it is no longer necessary to determine whether a response has been received from the second WCD, due to the receipt of the transition message or an identification code. sent by the second WCD (as explained later). In step 414, a second countdown timer is started to determine if the second WCD responds to the acknowledgment message within a predetermined period of time.

Returning to step 408, if the WCD determines that it did not initiate the current communication (the second WCD, in this example), it sends an identification code to the first WCD to allow the first WCD to establish a second communication using the second service option. along with the identification code, as shown in step 416. In one embodiment, the identification code comprises a telephone number associated with the WCD for use only in a particular service option. For example, each WCD may have a unique telephone number assigned to it for each service option offered by the service provider. In this case, the WCD transmitting the identification code could transmit the telephone number associated with the service option identified in the transition message. In step 420, the first countdown timer of the second WCD is canceled. In step 422, an optional third countdown counter is started within the second WCD to determine if the first WCD responds within a predetermined amount of time after transmission of the identification code.

In step 424, the first WCD receives the identification code. In step 426, the second countdown timer of the first WCD is canceled, due to receipt of the identification code. At step 428, an optional second acknowledgment message is transmitted to the second WCD to acknowledge receipt of the identification code. In step 430, the second acknowledgment message is received by the second WCD, and the third countdown timer is canceled within the second WCD in step 432.

At step 434, the first WCD now begins the process of transitioning the communication from the first service option to the second service option, using methods that are well known in the art. For example, a termination message is transmitted to the infrastructure (ie, base station 106, BSC 112, etc.), which terminates the present communication using the first service option. A termination message is transmitted to the second WCD by the infrastructure. Then, in step 436, a second communication is initiated using the second service option, via the first WCD, transmitting a source message requesting a communication to the second WCD using the second service option. Optionally, the source message comprises the identification code transmitted by the first WCD. The infrastructure processes the communication as usual, allocating infrastructure resources to handle the communication using the second service option, locating the second WCD in the wireless system (or outside the wireless system), and sending a paging message to alert the second WCD regarding the presence of the second communication.

In step 438, the communication using the second service option is established by the second WCD responding to the paging message, and accepting the communication, as is well known in the state of the art.

In one embodiment, the second WCD can only accept the second communication if it originates from the first WCD. In this embodiment, an identification code corresponding to the first WCD is transmitted up to the second WCD prior to the termination of the first communication. This identification code may identify the first WCD in the second service option only, or it may represent a simple identification code assigned to the first WCD. The received identification code is stored in memory 206.

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In either case, when the first communication ends, a fourth countdown timer is started inside the second WCD. The fourth countdown timer is used to set a time window in which calls from WCDs other than the first WCD will not be accepted. The idea is to allow the transition to occur without interruption from other WCDs.

The second WCD may be provided with an identification code identifying the first WCD in the paging message during the initialization of the second communication. When the paging message is received by the second WCD, the originator of the call is identified using well-known techniques similar to the caller ID. Prior to accepting the second communication, the second WCD compares the identification code contained within the paging message with the identification code stored in the memory 206 of the first WCD during the first communication. If the codes are matched, the second communication is accepted. Without the identification codes they are not paired, and the fourth countdown timer has not expired, the call is rejected. If the fourth countdown timer has expired, the call is accepted whether or not the identification codes are paired with each other.

In certain cases, the first WCD may already know the identification code of the second WCD used for communications that include the second service option. For example, the first WCD may be provided with a number of identification codes corresponding to one or more WCDs, each WCD having an identification code corresponding to a specific type of service option. In this situation, the identification code for the second service option may not need to be transmitted during a service option transition.

Figure 5 is a flow chart illustrating this point. In step 500, a communication is initiated between a first WCD and a second WCD using a first service option, the first WCD having initiated communication, in this example. Additionally, the first service option comprises a voice service option, although it should be understood that the first service option could alternatively comprise a synchronous data service option, an asynchronous data service option, or some other service option. offered by a wireless service provider.

In step 502, the users of the first and second WCDs are satisfied to transition the communication to a second service option, in this example, a secure data communication using an asynchronous data service option offered by the service provider. wireless. At step 504, one of the users initiates the transition, generally by pressing a key located on a respective WCD. In this example, the first WCD initiates the transition.

In step 506, the first WCD determines whether an identification code corresponding to the second wCd is available during the second service option. Availability is generally determined by the first WCD that checks the memory 206 inside the first WCD. If the identification code is available, then the first WCD transmits an "I Know Your Number" (IKYN) message to the second WCD in step 508. An optional countdown timer is started, as shown in step 510, upon transmission of the IKYN message. If, in step 506, the identification code is available for the first WCD, a transition message is sent, asking the second WCD to send its identification code for use in the second service option.

In step 514, the second WCD receives the IKYN message. In response, the second WCD transmits an acknowledgment message back to the first WCD, acknowledging receipt of the IKYN message, as shown in step 516. The second WCD does not transmit its identification code corresponding to the second service option due to that the IKYN message indicates that the first WCD already knows which identification code it is.

In step 518, the first WCD now begins the process of transitioning the communication from the first service option to the second service option, as explained above. The optional countdown timer is also reset at this stage.

Figure 6 is a flow chart illustrating an IKYN service option transition when requested by the second WCD, that is, the WCD that was called by the WCD that initiated the first communication. In step 600, a communication is initiated between a first WCD and a second WCD using a first service option, the first WCD having initiated communication.

At step 602, a decision is made to transition the communication to a second service option, either jointly by both users or unilaterally by either user. In both this and other examples contained herein, the transition can also be started automatically as soon as the initial communication is established.

At step 604, the user of the second WCD initiates the transition, generally by pressing a key located on their respective WCD.

In step 606, the second WCD transmits a transition message to the first WCD. The transition message informs the first WCD that a service transition is desired. In one embodiment, the transition message

ES 2 314 031 T3 comprises information identifying the preferred service option to transition to, for example, an asynchronous data service option. In one embodiment, the first WCD selects a default service option to transition to.

In step 608, the first WCD determines whether an identification code corresponding to the second WCD is available during the second service option. Availability is generally determined by the first WCD checking the memory 206 inside the first WCD. If the identification code is available, then the first WCD simply transmits an "identification code received" type of acknowledgment message up to the second wCd in step 610, informing the second WCD that the second WCD's identification code does not needs to be broadcast. The second WCD therefore does not transmit its identification code upon receipt of the acknowledgment message. In step 608, if no identification code is available, the first WCD sends an acknowledgment message that queues the second WCD to transmit its identification code in step 614.

In step 612, the first WCD now begins the process of transitioning the communication from the first service option to the second service option, as explained above.

Using the procedures described above to facilitate a seamless service option transition, a potential problem can arise if a three-way communication is established. In this scenario, a first WCD contacts a second WCD using a first service option, for example, a voice service option. The first WCD then contacts a third WCD using the same service option to establish a three-way call. The first WCD then withdraws from three-way communication (i.e., voluntarily interrupting communication or dropping communication for any number of reasons, such as leaving a wireless coverage area), leaving only the second WCD and the third WCD involved in communication. In this scenario, both the second WCD and the third WCD have been contacted by another WCD to establish communication (the second WCD has contact with both and has initiated a communication). Therefore, both WCDs estimate that they did not initiate the initial communication using the first service option.

In another related situation, both WCDs can estimate that it was they who initiated the first communication using a first service option. In this case, a first WCD contacts a second WCD. Next, a third WCD contacts the second WCD, and all three WCDs are engaged in three-way communication. If the second WCD withdraws from communication leaving only the first WCD and the third WCD, each of the remaining WCDs believes that they are the ones who initiated the communication.

If a service option transition is now desired between the remaining WCDs, problems with the transition will occur. In the first situation (both WCDS believe that they were not the ones who initiated the initial communication), neither WCD will initiate the second communication under the transition procedures described above. In the second situation (both WCDs estimate that they initiated the initial communication), both WCDs will try to initiate the second communication. In either case, the service option transition will fail.

Figure 7 is a flow chart illustrating an embodiment of the present invention for successfully transitioning a communication from a first service option to a second service option when both WCDs believe that they did not initiate the initial communication.

In step 700, a first WCD and a second WCD are already engaged in an initial communication using a first service option. Both WCDs believe that they did not initiate the initial communication, as described above. In step 702, both users of the WCDs decide to transition the communication to a second service option.

In this example, the second WCD initiates the service option transition by sending a transition message to the first WCD, as shown in step 704. The transition message is received by the first WCD in step 706, and in step 708, the first WCD sends an identification code corresponding to the first WCD. In another embodiment, the identification code corresponds to the first WCD when it has been used in a second service option.

In step 710, the second WCD receives the identification code transmitted by the first WCD. Receipt of the identification code is an unexpected condition for the second WCD. Therefore, upon receipt of the identification code, the second WCD transmits its own identification code to the first WCD in step 712.

In step 714, the first WCD receives the identification code from the second WCD. Again, this is an unexpected reception for the first WCD.

In step 716, both WCDs perform an analysis to determine which WCD should initiate the service option transition (ie, terminate the first communication and initiate a second communication using the second service option). In one embodiment, each WCD compares its own identification code with the identification code received from the other WCD. In this embodiment, the WCD having an identification code plus

ES 2 314 031 T3 low (or higher, in an alternative embodiment), takes responsibility for initiating the transition. For example, if the identification code associated with the first WCD is 858-651-2356 and the second identification code is 858-2235584, the codes are converted to decimals and then compared with each other. In this case, the second WCD would initiate the service option transfer, since 8,582,235,584 is less than 8,586,512,356. Of course, other manipulations of the identification codes could be used as an alternative to choosing the initiating WCD. For example, the initiation codes could be converted to decimals and each divided by the other. If the result is greater than 1, then a default WCD would initiate the service option transition. Many other techniques could be used as an alternative.

Other techniques could be used as an alternative for the comparison of identification codes. For example, an indication of the GPS position of each WCD could be transmitted from each to the other for comparison. Alternatively, a random number could be generated on each WCD, transmitted to the other WCD, and compared.

In either case, in step 716, one of the WCDs is chosen to initiate the second communication. In step 718, the chosen WCD now begins the communication transition process from the first service option to the second service option, as explained above.

Figure 8 is a flow chart illustrating an embodiment of the present invention for successfully transitioning a communication from a first service option to a second service option when both WCDs believe that they initiated the initial communication, as indicated. described above.

In step 800, a first WCD and a second WCD are already engaged in an initial call using a first service option. Both WCDs believe that they initiated the initial communication, as described above. In step 802, one or both users of the WCDs decide to transition the communication to a second service option.

In this example, the first WCD initiates the service option transition by sending a transition message to the second WCD, as shown in step 804. The transition message is received by the second WCD in step 806, and in step 808, the second WCD sends an acknowledgment message to the first WCD thinking that it was the WCD that initiated the first communication.

In step 810, the acknowledgment message is received by the first WCD. This is an unexpected result that is a signal to the first WCD that both WCDs believe that it was each of them that initiated the initial communication. In response, the first WCD then sends an acknowledgment message back to the second WCD in step 812.

In step 814, the acknowledgment message from the first WCD is received by the second WCD. Receipt of the acknowledgment message is an indication to the second WCD that both WCDs believe that they initiated the initial communication.

In step 816, both WCDs exchange their respective identification codes. In step 818, both WCDs perform an analysis to determine which WCD should initiate the service option transition, as explained above with respect to Figure 7. In step 820, the chosen WCD now begins the process. transition of communication from the first service option to the second service option, as explained above.

Thus, the preferred embodiments of the present invention have been shown and described. It is apparent to those skilled in the art, however, that numerous modifications can be made to the embodiments described herein without departing from the scope of the invention as defined in the appended claims. Therefore, the present invention should not be considered limited except in accordance with the claims that follow.