Abstract:
A system and method for providing chat group services to wireless mobile terminals is disclosed. The chat forum permits integrated voice and text messaging. The system includes plural mobile terminals, each being capable of running a chat client application. A server complex is connected to one or more wireless carrier networks by way of a packet-based network, such as the Internet. The server complex includes server applications and components for supporting the chat group services and communicating with the chat clients on the mobile terminals. The system also includes features that permit the integration of legacy mobile terminals, communication with machine interfaces using a chat metaphor, and robustness and reliability of operation across various wireless operators.

Description:
[0001]    This application is a continuation-in-part of U.S. patent application No. 10/197,022; filed on Jul. 17, 2002 and entitled “Voice and Text Group Chat Display Management Techniques for Wireless Mobile Terminals”, which is hereby incorporated by reference. 
     
    
     
       TECHNICAL FIELD  
         [0002]    The present invention relates generally to communication systems incorporating speech and textual input and output modalities and, in particular, to a wireless system for permitting real-time speech and text conversations (e.g., chat threads) on mobile units.  
         BACKGROUND OF THE INVENTION  
         [0003]    Text and, to a lesser degree, speech chatting systems, are generally known in the art, particularly in relation to personal computing systems. Published U.S. Patent Application Nos. 2001/0042095 A1; 2001/0011293 A1; and 2002/0023128 A1 and U.S. Pat. Nos. 6,212,548 and 6,286,034 illustrate exemplary system and user interfaces used today. A common feature of such systems is that the various conversations (or threads) are usually split out into distinct regions (or windows) on the display or screen. Furthermore, when a single thread comprises a plurality of both text and speech exchanges, such systems usually separate the two modalities. The speech is usually played over a speaker, whereas the plurality of text messages are displayed on the screen. Users have no means to reference old speech messages or distinguish when they occurred in the thread relative to other messages in that thread.  
           [0004]    Published U.S. Patent Application No. 2002/0023128 A1 (“the &#39;128 Publication”) describes a system where the screen area is split into six distinct windows. One window presents a chat history of one thread (the thread in focus) while another window displays a chat history of the combined plurality of the remaining threads. A chat history comprises a plurality of entries displayed on the screen that describe both inbound (i.e., received by the user&#39;s mobile terminal) and outbound (i.e., sent by the user&#39;s mobile terminal) chat messages. The entries are usually displayed on the screen in chronological order and usually only describe text messages.  
           [0005]    Although the above-described chat systems fulfill the needs of some chat group users, they do not readily provide for integration with pre-existing mobile messaging systems. With known chat systems, during a chat session, subscribers can not conveniently contact or communicated with legacy mobile users operating outside of the chat message system. Therefore, there is a need to provide a chat system that permits chat threads between mobile users running chat applications and mobile users on legacy, out-of-band messaging systems.  
         SUMMARY OF THE INVENTION  
         [0006]    It is an advantage of the present invention to provide novel methods and systems for managing both single-modal (i.e., either voice or text) and multi-modal (i.e., voice and text) wireless chat systems.  
           [0007]    According to one embodiment of the invention, a wireless system permits chat-based communications between legacy mobile terminals and non-legacy mobile terminals. The non-legacy terminals execute a chat client application that provides chat services over wireless carrier networks. The legacy terminals generally lack the chat client, and are instead capable of data communication over an alternative data messaging service, such as a Short Messaging Service (SMS) conventionally provide by wireless operators. Communication between the legacy and non-legacy terminals is achieved as follows. First, an outbound chat message from the non-legacy mobile terminal is received at a server complex. The outbound message includes an address corresponding to the legacy mobile terminal. Components within the server complex detect the legacy address, and in response, build an inbound message that includes the originator address and is to be sent to the legacy terminal. The inbound message is sent to an aggregator, which then injects the inbound message into an out-of-band messaging system for delivery to the legacy mobile terminal. A reply message generated by the legacy terminal can be sent either directly to the non-legacy terminal over the SMS system or through the server complex over the SMS system, based on the originator address.  
           [0008]    The techniques disclosed herein deliver such services over wireless packet networks bridging users across wireless operators using standard data transfer technologies in a manner that is not dependent on the wireless operator, or the underlying network technology used. This overcomes many of the challenges involved in providing universal wireless chat services, such as frequent change of IP address, dropped connections, blocking of network-initiated messages, and wireless resource contentions. The techniques also describe methods to integrate with legacy phones, initiate VoIP telephony calls, invoke commands, detect and transcode voice across various codecs, manage speech delivery within a context of a plurality of conversation threads, and how to communicate delivery receipts. Additionally, the systems and methods of the present invention accommodate the use of speech-based methods in chat environments. Additionally, they describe methods and systems for integrating machine-based services using multi-modal chatting interfaces.  
           [0009]    Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.  
         [0011]    [0011]FIG. 1 is a schematic illustration of a wireless mobile terminal usable in a chat system.  
         [0012]    [0012]FIG. 2 is a block diagram of a wireless communications system in accordance with an embodiment of the present invention.  
         [0013]    [0013]FIG. 3 is a block diagram of wireless communication chat components included in the system of FIG. 2.  
         [0014]    [0014]FIG. 4 is a schematic illustration of an outbound text message usable in the system of FIG. 2.  
         [0015]    [0015]FIG. 5 is a schematic illustration of an inbound text message usable in the system of FIG. 2.  
         [0016]    [0016]FIG. 6 is a schematic illustration of a buddy list update message usable in the system of FIG. 2.  
         [0017]    [0017]FIG. 7 is a table that illustrates the data contained in the presence manager shown in FIG. 2.  
         [0018]    [0018]FIG. 8 is a table that illustrates the data contained in the nickname manager shown in FIG. 2.  
         [0019]    [0019]FIG. 9 shows a buddy list display, presenting an exemplary nickname list in alphabetical order.  
         [0020]    [0020]FIG. 10 shows a buddy list display, presenting an exemplary nickname list in group order.  
         [0021]    [0021]FIG. 11 is a schematic illustration of a chat history display.  
         [0022]    [0022]FIG. 12 is a schematic illustration of a title bar for the chat history display when speech is recorded.  
         [0023]    [0023]FIG. 13 is a schematic illustration of a detail view display of an exemplary single communication message.  
         [0024]    [0024]FIG. 14 is a schematic illustration of a text message editor.  
         [0025]    [0025]FIG. 15 is a block diagram of a wireless communications system that has been extended to integrate legacy mobile terminals in accordance with a further embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]    The present invention may be more fully described with reference to FIGS.  1 - 15 . FIG. 1 illustrates a wireless mobile terminal  100  that may comprise any wireless communication device such as a handheld cellular phone or a wirelessly enabled Personal Digital Assistant (PDA). The configuration of the mobile terminal  100  shown in FIG. 1 is exemplary only, and it is generally understood that a variety of terminals and terminal configurations could be used. As shown, the mobile terminal  100  comprises a speaker  103  for rendering signals, such as received speech, audible; a display  102  to render text and graphical elements visible; a navigation rocker  105  that allows a user to navigate a list or menu displayed on the screen; programmable buttons (or “softkeys”)  104 ; a keypad  106  that allows the user to input digits, letters, and other symbols (e.g., punctuation); a microphone  107  that captures audio such as the user&#39;s speech; and a push-to-talk button  101  that allows the user to initiate recording and transmission of audio. These and other components of the mobile terminal (not shown) are well known in the art and need not be described in greater detail herein. Additionally, there are a variety of styles and instances of components that can be used instead of (or in conjunction with) the components described in FIG. 1. For example, the push-to-talk button  101  may be omitted and replaced with automatic voice detection mechanisms. Touch screens and hand writing recognition techniques can replace the need for the softkeys  104 , the navigation rocker  105 , and the keypad  106 . The present invention is not limited in this regard. Additional components of the terminal that are not necessarily visible to the user but are necessary to implement chat functionality are further described with reference to FIG. 3. The input devices available on the wireless mobile terminal (e.g., keypad, softkeys, etc.) may be employed by a user of the wireless mobile terminal to initiate a session of chat software and, within the operation of the chat software, to initiate one or more chat conversations (threads) as described in greater detail below.  
         [0027]    [0027]FIG. 2 illustrates the overall system architecture of a wireless communication system comprising a plurality of mobile terminals  100  in accordance with an embodiment of the present invention. The terminals  100  communicate with at least one chat server complex  204  by wirelessly transmitting data to a corresponding wireless carrier&#39;s infrastructure  202 . As known in the art, the wireless carrier infrastructures  202  comprise those elements necessary to support wireless communications with the terminals  100 . Various service providers (such as Verizon or Sprint in the U.S., or Orange in Europe) build and maintain such infrastructures. The data packets are sent on to a communication network  203  that forwards them onto the server complex  204 . The communication network  203 , which is a packet-based network, may comprise a public network such as the Internet or World Wide Web, a private network such as a corporate intranet, or some combination of public and private network elements. The server complex  204  preferably comprises a plurality of networked server computers that may be programmed to implement the functionality described below. The particular number of servers used and the manner in which they communicate with each other is a matter of design choice. Techniques for programming server computers and mobile terminals are well known in the art.  
         [0028]    When the server complex  204  communicates with one or more mobile terminals, the server complex  204  sends its data to the network  203  that, in turn, forwards the data onto at least one of the carrier infrastructures  202 . Each relevant carrier infrastructure  202  then transmits the data to one or more of its corresponding mobile terminals  100 . Preferably, when a plurality of users chat together (i.e., send chat messages from one terminal  100  to another), data comprising text, speech, and/or graphical messages (or some combination thereof) are sent to the server complex  204 . The server complex  204  then sends copies of the message out to the targeted terminals  100 , preferably including, in one embodiment, the initiating or sending terminal.  
         [0029]    The server complex  204  can be placed inside a wireless carrier&#39;s infrastructure  202 , or that it may be eliminated in cases where direct terminal-to-terminal transfer is supported. In the latter case, substantially all of the chat messaging functionality is supported by the mobile terminals. Furthermore, the present invention would benefit systems other than packet data based systems, as well as systems that are limited in scope to a single wireless carrier&#39;s domain.  
         [0030]    In the preferred embodiment, at least one chat server complex  204  resides outside the carrier&#39;s domain. As such, it is able to services a plurality of mobile terminals  100  that can be associated with a plurality of wireless carriers. In effect, the systems disclosed herein are independent of the wireless operators. They do not require any special hardware or software to be placed within the operator wireless network  202 . The wireless operator&#39;s network (in conjunction with a public network  203 ) acts as a communication pipe between the mobile terminal  100  and the server complex  204 . Preferably, standard packet data transfer protocols are used to transmit and route data messages back and forth between the mobile terminal  100  and the server complex  204 , such as the Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and World Wide Web protocols, such as the Hypertext Transfer Protocol (HTTP). The server complex  204  acts as a gateway between the various transfer protocols. Each of the plurality of mobile terminals  100  establishes a connection with the chat server complex  204  using a suitable transfer protocol. Messages flow from the mobile terminal  100  into the server complex  204  over at least one protocol. The server complex  204  copies the message&#39;s content and broadcasts it to other intended recipient mobile terminals  100  using the appropriate transfer protocol suitable for each of the targeted mobile terminals  100 .  
         [0031]    [0031]FIG. 3 illustrates in more detail components found in both the terminals  100  and the server complex  204  used to exchange group speech and text chat messages. Focusing on the components of the terminal  100 , machine-readable and executable instructions (typically referred to as software, code, or program) are preferably stored in an application storage (or memory)  310  and executed (or run) on a central processing unit (CPU)  211 . All storage devices described herein may comprise any combination of volatile (e.g., random access memory) or non-volatile (e.g., read-only memory) storage as known in the art. Likewise, the CPU  211  may comprise a microprocessor, microcontroller, digital signal processor, co-processor, similar devices or combinations thereof. Using known programming techniques, the software can manipulate the display  102 , capture speech from the microphone  107 , capture input data from the keypad  106 , navigation rocker  105 , soft keys  104  and/or push-to-talk button  101  using the I/O controller  312 . Outbound chat messages sent to the server complex  204 , as well as those inbound chat messages received from the server complex  204 , pass through the network interface  306  that provides connectivity between the terminal and the data network. Where the terminal  100  comprises a wireless device, the network interface  306  comprises the entire physical interface necessary to communicate with the server complex  204 , including a wireless transceiver. Preferably, but not necessarily, speech sent to the server complex  204  is first encoded using a voice codec  307 , which may be implemented in software, but is preferably implemented using a combination of hardware and software components. Similarly, voice from the server complex  204 , may, when necessary, be decoded using the voice codec  307  before it is sent to the speaker  103 . The software uses temporary storage  309  to save working data that does not persist between software initiations (sessions). On the other hand, the software uses the permanent storage  305  to persist data for longer periods of time that can span multiple software sessions.  
         [0032]    Focusing on components of the server complex  204 , the data traffic comprising encoded speech and text messages (e.g., outbound chat messages  400 ; see FIG. 4) flows into the server complex  204  preferably via the router  301 . Note that the router  301 , presence manager  302 , message broadcaster  303  and nickname manager  304  may be implemented on one or more server computers or the like residing within the server complex  204 . The router  301  directs the outbound chat message  400  towards a message broadcaster  303  that determines the plurality of inbound chat message copies (e.g., inbound chat messages  500 ; see FIG. 5) needed and their destinations. In the context of the present disclosure, the term inbound refers to messages directed to one or more mobile terminals, whereas the term outbound refers to messages sent by mobile terminals. The message broadcaster  303  decomposes the incoming message  400 , and locates the list of recipient identifiers  402 . It then queries a presence manager  302  to establish the recipients&#39; current status  702  (i.e., an indicator of whether the recipient is ready to receive the particular type of message, speech and/or text messages only, etc.) and the terminal&#39;s address  703 . FIG. 7 illustrates a table with the plurality of presence data records  700  contained within the presence manager  303 . Each presence record  700 , comprises the user&#39;s identifier  701 , the current status  702 , the current terminal address  703  (if known), a public display identifier, such as a public nickname  704  and a public short name  705 , and a plurality of other user identifiers  706  that subscribe to the presence information of the user corresponding to that record. The public display identifiers or public nickname set  704 - 705  is used in inbound chat messages  500  sent to the terminal  100  unless the receiver (i.e., the receiving user) overrides the public nickname set  704 - 705  with private display identifiers or a private nickname set  802 - 803 . When presence status  702  changes, the presence manager  302  sends a buddy list update message  600  to all the subscribers listed in the subscriber identifier field  706  of the corresponding presence record  700 . The presence records  700  may contain other information and attributes such as forwarding address, processing rules that describe what to do in various circumstances, graphical representation for various status, profiles (i.e., a plurality of a different value sets that could be used at various times or depending on the receiver, etc.) and the like.  
         [0033]    Although not illustrated in FIG. 3, the server complex  204  may include other components such as authentication and encryption servers that ensure the authenticity of the chat communication messages and secure the privacy of their content. The server complex  204  may also include a plurality of other components like speech-to-text and text-to-speech translators, natural language translators, voice transcoders, and other similar transformation gateways that transform the message, its contents, and any attachments (e.g., ring-tones, images, and so on) to a more meaningful and usable format by the receiver. Techniques for implementing such other components are well known in the art.  
         [0034]    In the preferred embodiment, each of the plurality of wireless operators may deploy different wireless data technology in the wireless carrier network  202 , such as Global System for Mobile Communication&#39;s (GSM) General Packet Radio Service (GPRS) and Code-Division Multiple Access&#39;s (CDMA) Single Carrier Radio Transmission Technology (1xRTT). In this respect, the systems disclosed herein do not depend on the data wireless technology employed.  
         [0035]    In the preferred embodiment, the voice codec  307  used on the plurality of mobile terminals  100  is native to the terminals. The voice codec  307  native to the mobile terminal  100  is optimized for both the terminal&#39;s processing strategy and the wireless technologies used. In order for the system to be independent of the underlying wireless technology, the system uses commercially-available media scheme gateways (not shown). The media gateways transcode speech samples from one encoding to another. In operation, the message broadcaster  303  establishes the type of encoding used on the incoming message. It determines the type of encoding required for the each of the plurality of target mobile terminals  100 . For each copy of the message, the message broadcaster  303  uses at least one media gateway to transcode the speech to a coding scheme appropriate of the target recipient. Techniques for detecting the type of encoding used by the incoming message and or required by the target terminals, as well as interfacing to media gateways are known in the art. Exception processing in cases where the media gateway is unable to fulfill a conversion can also be performed by the system. For example, a message may be sent back to the sender informing the sender that the message was not delivered to the target recipient because the system does not support the required transcoding techniques.  
         [0036]    In addition, the system can be configured to optimize transcoding. For example, the message broadcaster  303  can reuse the same transcoding for all messages targeting mobile terminals  100  that require the same encoding. In addition, the message broadcaster  303  can avoid transcoding the speech if it detects that the message cannot be otherwise delivered to a target. Other optimization techniques can be employed as well.  
         [0037]    In the preferred embodiment, the plurality of mobile terminals  100  are grouped and allocated among a plurality of chat server complexes  204 . As such, each server complex  204  services a set of homogeneous mobile terminals  100  requiring the same speech encoding. Multiple server complexes  204  may use the same encoding. When a message reaches the message broadcaster  303  of one of the chat server complexes  204 , the broadcaster forwards at least a copy of the message to another server complex  204  managing the connection with a subset of the intended recipients of the message. The message forwarded is transcoded by a media gateway in route between the two server complexes  204 . The system benefits from using a common encoding for transferring the speech sample between the various server complexes  204 . In particular, the message that is received by a server complex  204 , is transcoded into the common encoding before it is forwarded to the plurality of other target server complexes  204  (only one transcoding is required in this case). Upon arrival of the message into each of the plurality of target server complexes  204 , the message is converted into the encoding that is suitable for the target mobile terminal  100 . Only one encoding at the end server complex is needed since all the terminals serviced by the complex use the same encoding. Messages not forwarded outside the server complex  204  need no transcoding since all the mobile terminals serviced by the complex use the same encoding. In this arrangement, simpler media gateways may be deployed between the complexes  204  because the gateways only need to transcode content between the common encoding and the encoding used by the mobile terminals  100  serviced by the complex  204 . Also, detection of the type of transcoding required is inherent in the routing of messages i.e., structure and distribution of mobile terminals and does not required actual resolution based on any encoding information itself. It is done based only on the target address of the mobile terminal, which is resolved in all cases to route and direct messages. For example, instead of using multiple server complexes  204 , a single server complex  204  can be subdivided where a plurality of message broadcasters  303  are used in the same spirit as distributed server complexes  204 . The invention is not limited to any particular arrangement of server complexes. Alternative arrangements can be employed for the server complexes.  
         [0038]    Preferably, a nickname manager  304  resides in the server complex  204  and is responsible for managing lists of nickname sets  802 - 803  used by the receiver of an inbound chat message  500  to override public nicknames and short names. Note that nicknames and short names differ primarily in their length. Nicknames may be of any arbitrary length (possibly limited as a matter of design choice), whereas short names are preferably fixed in length or size. Additionally, nicknames and short names are instances of display identifiers used to identify the originators of chat messages. Such display identifiers are distinguished from identifiers used internally by the system to identify particular users (e.g., identifiers having reference numerals  701 ,  403 , and  604  in the accompanying FIG.s). It should also be noted that short names might differ from nicknames in format or type. The system may use graphical, symbolic or other suitable forms of short names that are compact and fixed in dimension while using textual forms for nicknames. The system may vary the graphics and symbols based on context, user preferences, presentation themes and personalities.  
         [0039]    [0039]FIG. 8 illustrates the nickname record  800  contained within the nickname manager  304 . Preferably, each nickname record  800  comprises a receiving user&#39;s identifier  701 , the buddy&#39;s identifier  801  (i.e., the identifier of the chat buddy for whom the receiving user desires the message broadcaster  303  to replace the buddy&#39;s public nickname set  704 - 705  with the receiver&#39;s private nickname set  802 - 803  on all inbound chat messages  500 ) and the private nickname  802  and private short name  803 . Like the case of presence records  700 , the nickname records  800  may contain other information and attributes such as forwarding address, processing rules, graphical representation for various status, profiles (i.e., different field values that could be used in various times, etc.) and so on. Upon receiving a message targeted to a recipient designated by the receiving user&#39;s identifier  701 , the nickname manager  304  determines the buddy identifier  801  (i.e., the identification of the chat participant that initiated transmission of the message). Based on the buddy identifier  801 , the nickname manager  304  inspects the nickname records corresponding to the targeted recipient. If the buddy identifier is not found in the targeted recipient&#39;s nickname records, the message is sent to the targeted recipient as in inbound message with the public nickname and public short name of the sender. In this case, the public nickname and/or short name of the sender will thereafter be displayed on the targeted recipient&#39;s mobile terminal display. If the buddy identifier is located in the targeted recipient&#39;s nickname records, the nickname manager determines the private nickname and private short name associated with the buddy&#39;s identifier and replaces the public nickname with the private nickname and the public short name with the private short name in the subsequent inbound message sent to the targeted recipient, thereby causing the private nickname and/or private short name to be displayed on the recipient&#39;s mobile terminal display. In this manner, users (i.e., recipients) have a greater degree of control over how chat histories are displayed on their terminals. Note that the process of determining private display identifiers and substituting them for public display identifiers could be performed by the mobile terminals assuming that the necessary nickname records are stored on the mobile terminals.  
         [0040]    [0040]FIG. 4 illustrates an outbound chat message  400  that the terminal  100  sends to the message broadcaster  303 . The outbound chat message  400  comprises a message type  401  (e.g., text, speech, and so on), a number of intended recipients  402 , a plurality of recipient identifiers  403 , a thread identifier  404 , a message length  405 , message content  406 , and a number of attachments  407 . Preferably, the mobile terminal  100  generates the thread identifier  404  by aggregating a client identifier and a session identifier with a thread sequence number. The thread sequence number is a terminal-side number that starts from 0 each time a session is initiated. The client increments the thread sequence number by 1 each time the terminal  100  generates a new thread. Although not illustrated in FIG. 4, the payload may contain message encoding types and other attachments (e.g., icons, ring-tones, and so on). Other elements can be added to the outbound chat message, such as sequence numbers, time stamps, or the like.  
         [0041]    The message broadcaster  303 , upon receiving the outbound chat message  400 , first compiles a list of target recipients comprising the sender&#39;s identifier (i.e., the first recipient identifier in the recipient identifier list  403 ) and the plurality of other recipient identifiers (i.e., the recipient identifiers in the identifier list  403  other than the sender&#39;s identifier). For each target, the message broadcaster  303 , determines the status  702  of the target by locating the target&#39;s identifier in a presence record  700  with the matching identifier  701 . For each available target (i.e., where the presence record indicates that the recipient can receive the message type  401 ), the broadcast manager  303 , composes an inbound chat message  500 . The message broadcaster  304  queries the nickname manager  304  to find the receiver&#39;s local nickname set  802 - 803  for the other recipients (i.e., the identifiers comprising the original list of targets without the receiver&#39;s identifier.) If no information is found (i.e., the receiver did not build a nickname record  800  for the particular recipient), the message broadcaster  304  queries the presence manager  302  for the recipient&#39;s public nickname information  704 - 705 . The message broadcaster  303  extracts the receiver&#39;s address  703  from the presence manager  302  and sends the inbound message  500  to the receiver&#39;s terminal  100  via the router  301 . Those having ordinary skill in the art will doubtlessly recognize that means to optimize the creation and broadcasting of messages, such as using common compression and encoding techniques may be employed, and that other information may be included in the inbound chat message  500 , such as sequence numbers, timestamps, and so on.  
         [0042]    [0042]FIG. 5 illustrates an inbound message  500  sent by the server complex  204  to the terminal  100 . As shown, the inbound message  500  is largely a copy of an outbound chat message  400  sent from a terminal  100  to the server complex  204 . The inbound message  500  preferably comprises the original outbound message  400  and a definition of new users not known to at the terminal  100  (i.e., not already in the receiver&#39;s buddy-list.) The new user definition comprises the number of new definitions  501  and a plurality of individual definitions comprising the recipient&#39;s identification  502 , full name  503 , public nickname  504 , and public short name  505 . In some cases, the original outbound message has to be transformed to be understood by the receiving terminal  100 . It should also be noted that the server complex  204  may only need to include the new user definition once during a session. That user definition is placed in the terminal&#39;s  100  temporary storage  309 . This enables less wireless data transfer. Other attributes can be placed in the inbound chat message  500  including such things as time stamps, sequence numbers, and so on. It should be noted also, that anonymous identifications and virtual or group identification could be used as well.  
         [0043]    When a participant&#39;s presence status  702  changes, the message broadcaster  303 , sends a buddy list update message  600  to other users subscribed to the participant&#39;s presence status  702 . FIG. 6 illustrates a buddy list update message  600  sent from the server complex  204  to the mobile terminal  100 . The message  600  comprises a list type  601  (e.g., alphanumeric list, group list, etc.), the number of groups identified in the message  602 , at least one group definition  603 - 604 , a list of ungrouped individuals  605 - 606 , and a plurality of user definitions  502 - 505 ,  607 . Note that the recipient status field  607  indicates the value of the presence status  702 . A group definition, in this context, comprises a group name  603  and a plurality of recipient identifiers  604 . A recipient&#39;s identifier can exist in a plurality of group definitions. However, preferably, there will be only one user definition  502 - 505 ,  607 . Furthermore, preferably, for each identifier in the list of recipient&#39;s identifiers  604 , there is at least one user definition  502 - 505 ,  607  for that recipient in the buddy list update message  600 . The list of ungrouped individuals is a special unnamed group. It comprises the number of ungrouped individuals  605  and the list of recipient identifiers  606 . Preferably, recipient identifiers in the ungrouped definition cannot be in other groups. The records  600  can contain other fields of attributes and information such as presentation icons, audicons, or the like. In addition, it should be noted that the message does not have to contain the entire list of groups and individuals on updates, rather incremental updates could be used instead.  
         [0044]    The presence manager  302  may send buddy list update messages  600  to the terminal  100  upon receiving a refresh request from the terminal  100 . Those having ordinary skill in the art will recognize other reasons to send buddy list updates (e.g., initial connection,) as well as optimizations in the form of encoding the contents, sending incremental updates instead of the entire list, and so on.  
         [0045]    In another embodiment, parts (or all) of the functionality of the message broadcaster  303  and the nickname manger  304  can reside on the terminal  100 . In that case, the terminal  100  communicates with the server complex  204  when it exchanges presence information. Chat communication messages are broadcast from one terminal  100  to the plurality of other terminals  100  in a point-to-point fashion.  
         [0046]    [0046]FIG. 9 illustrates a buddy list display with its entries sorted alphabetically. In a preferred embodiment, the screen  102  is divided into three regions. In a topmost region, there is a title bar region  901  allowing the display of one line of text and graphic symbols (i.e., icons). The software uses this region  901  to provide the user notices and other meta-information about the current task. In the case of the buddy list display, the title bar  901  comprises the user&#39;s own presence indicator  904 , the user&#39;s own public nickname  704 , and, on occasion, an inbound chat message indicator  905 . Preferably, the presence indicator  904  is a icon that varies in appearance depending and the presence status  702  (i.e., there is a different and distinguishable feature associated with the various status values). Preferably, the inbound chat message indictor  905  is an icon accompanied by an audible sound when the icon is first displayed. Combined, the visual and audible notice indicate to the user that there is at least one unheard and/or unread inbound chat message  500  that has arrived at the terminal  100 . If the user&#39;s nickname is too long for the title bar  901 , the software scrolls the title bar leaving only the inbound chat message indicator  905  in a fixed position for quick access. There are many familiar examples in the art today of such display techniques, any of which may be incorporated for use with the present invention.  
         [0047]    In the middle region of the display is a content region  903 . In the case of the buddy list display, the software preferably places a multi-selection list in the content region  903 , which list has a plurality of entries each representing a buddy that was received by the terminal  100  from the server complex  204  in a buddy list update message  600  and stored in the temporary storage  309 . Each entry can be highlighted  908  by the user. Highlighting and navigating list entries are implemented using common techniques in the art. Each entry in the list comprises a selection indictor  906  that indicates whether the user has selected the particular buddy for chatting (i.e., sending a chat communication message), the buddy&#39;s presence indicator  911 , the buddy&#39;s nickname  802  or  704 , and/or the buddy&#39;s short name indicator  907 . Note that symbols other than text could serve the same function as the short name indicator  907  for the short name information  705  or  803  as indicated previously. For example, icons or other graphical elements could be used so long as they sufficiently differentiate buddies from one another. Further still, a combination of such graphical elements and text could be used if sufficient screen space is available.  
         [0048]    On the bottom of the screen  102  is a softkey label region  202 . Preferably, there is a minimum of two labels  909 - 910 . The number of labels depends on the actual number of softkeys  104  available on the terminal  100 . In the illustrated embodiment, the left softkey label  910  is “select” while the right softkey label  909  is “write” if there is at least one selected entry in the buddy list. Otherwise, the right softkey label  909  is labeled “chat”. If the user activates the left softkey with a single click (referred to onward as “single-clicking”), the highlighted entry  908  is selected (or deselected if it was already selected,) and consequently its selection indicator  906  changes to reflect the new state. If the user presses and holds (referred to onward as “click-holding”) the left softkey, the software presents the user with a plurality of options such as the option to deselect or select the entire list; switch to other displays (e.g., chat history display described in FIG. 11, group ordered buddy list display described in FIG. 10, etc.); request the details of the buddy (e.g., full name, the public nickname set  704   705 , etc.); change the nickname set  802 - 803 ; show or hide fields (e.g., the short name indicator  907 ), and so on. Once again, techniques for programming such functionality and associating it with single-clicking and/or click-holding are well known in the art. It should also be noted that the use of a text string to represent a softkey label is exemplary and only intended to capture the spirit or intent of the invention. Other forms of labels can be used, such as graphical symbols, and the like.  
         [0049]    If no buddies are selected, the right softkey label is “chat”. Single-clicking or click-holding the right softkey in this context switches the user to chat history display described in more detail with reference to FIG. 11. If the user pushes the push-to-talk button  101  (referred to onward as pushes-to-talk,) an audible indicator reminds the user that buddies have to be selected first. If there is at least one buddy selected, single-clicking or click-holding the right softkey begins to compose a message for a new thread to the selected buddies. The display in that case switches to the text message editing display described in more detail with reference to FIG. 14. If the user pushes-to-talk, the display switches to the chat history, and the user is able to record and transmit a speech message and consequently start a new thread with the selected buddies.  
         [0050]    [0050]FIG. 10 illustrates a buddy list display with its entries sorted by group. In a preferred embodiment, group entries and their member buddies are listed first followed by a list of ungrouped buddies. Individual entries are identical to those displayed in an alphabetically ordered list with the exception to a preferred indentation (i.e., an annotation that indicates membership to a group). Group entries comprise a group name  1005  and a group selection indicator  1001  which is similar to the individual selection indicator  906  except that a group selection indicator can indicate more that just selected and unselected states; it can indicate partial selection as well. Referring to the examples illustrated in FIG. 10, solid squares (group selection indicators) such as in groups 3 and 4, are completely selected. Group 5 has an empty square indicating partial selection. If there is a group without any of its members selected, there is no indicator at all on the group level (or the individual buddy level). To select a group, a user can either select all the members one by one or select the group directly. To partially select a group, a user can start by selecting a group then deselecting one or more member. Alternatively, a user can start with an unselected group and select one or more members. A group entry can be collapsed (i.e., the members of the group are suppressed from the display.) In that case, the entry is annotated with a collapse indicator  1002 . If the user highlights a collapsed group for a length of time, the group automatically expands to show the members. When the user moves to another group, the group display style reverts back to its collapsed state again. If a user selects or deselects a group entry, all the members of the group are automatically selected or deselected. The softkey labels  1003 - 1004  are similar in behavior to those described with reference to FIG. 9. However, click-holding when a group entry is highlighted (or an individual within a group is highlighted) presents the user with additional options to mange the group, such as renaming the group; removing the group or its the member; adding a new group or individual, collapsing or expanding the group; collapsing or expanding all groups; and so on. It should be noted that, in a preferred embodiment, only one level of grouping is allowed (i.e., nested groups are not allowed), although multiple levels could be provided.  
         [0051]    Preferably, where the system supports presence profiles that are coupled to recipient users or groups, then as the user highlights the plurality of buddy entries  908 , the user&#39;s presence indicator  904  and nickname  704  in the title bar  901  will vary to indicate the presence information of that particular buddy (or group of buddies). Also, it should be noted that if the information in the highlighted entry  908  is too long, the software can scroll the information, expand it, or use other techniques common to the art to present all the information to the user.  
         [0052]    It is understood that there are other means to order lists (by date, events, and so on), and that other annotations could be added to the entries. For example, an indicator that there are messages that have not been read/heard available from the individual or group may be used.  
         [0053]    [0053]FIG. 11 illustrates a chat history display. The content region  903  of the display is a single selection list comprising a plurality of entries representing inbound chat messages  500  received by the terminal  100  and a plurality of entries representing outbound chat messages  400  transmitted by the terminal  100 . Outbound chat messages are preferably echoed back to the sender in full or in part (e.g., speech messages might not include the actual speech sent) in the form of inbound messages. That is, outbound chat messages go to the server complex for transmission to the targeted recipient(s). In addition to sending the message to the targeted recipient(s), the message broadcaster sends a copy of the outbound message to the transmitting terminal (i.e., the sender) as an inbound message. In some cases, the copy of the message (the inbound message) to the transmitting terminal might not be identical to the message that was sent (the outbound message). For example, in a presently preferred embodiment, the speech content of an outbound voice message is not copied back to the transmitting terminal; only a text portion of a voice message is sent back as in inbound message. Note that, in a presently preferred embodiment, voice messages have text appended to them, even if only a generic character string or symbol is used to indicate that the message was a voice message. Of course, if speech-to-text conversion is available, the actual speech content of the message could be converted to text and copied back to the transmitting terminal. In this manner, the occurrence of voice message results in an entry being displayed on the screen. In an alternative embodiment, rather than having the text of an outbound message sent back to the transmitting terminal via an inbound message, the transmitting terminal can locally echo the text to the display directly. In this manner, use of wireless resources may be minimized.  
         [0054]    A common problem in the art of chatting is the representation of successful delivery. A preferred approach to giving notice of delivery is to send an outbound message  400  back (as an echo inbound message  500 ) to the sender&#39;s mobile unit communicate to the sender that the message has been reliably delivered to the message broadcaster  303  in the chat server complex  204 . Alternatively, the representation of that notice can be a text message that is placed in the chat history with a message indicating that the message sent was received by all recipients. The echo can be sent back when the outbound message  400  is received by the message broadcaster  303 . The chat server complex  204  can then send a receipt notice when all the recipients have received the message. Preferably, the original echo is annotated when the delivery receipt arrives (e.g., changes color and/or font, or is adorned with a symbol like a check mark, etc.) to give notice of receipt. In an alternate approach, the echo message back to the user can be delayed until the broadcaster  303  has received confirmation that all intended recipients received copies of the message. However, the approach may present some presentation side effects that can be confusing to the user in environments where the delivery latency is relatively long and there is a high degree of latency variability between the deliveries of the plurality of copy messages. In such situations, at least one recipient may respond back to the sender before the message reaches the remaining recipients. In that case, the sender would see on his/her chat history display (see e.g., FIG. 11) the response to the message before the echo. Several techniques can be deployed to rectify this problem. For example, the mobile terminal  100  or the server complex  204  could delay presentation or delivery of the recipient response until the original message was received by all recipients and the echo sent back to the user.  
         [0055]    While not illustrated, at any time, the user may query the system as to who has (or has not) received the message. Other implementations may choose to forgo allowing the user to query the system for outstanding deliveries and instead provide comparable information by sending a plurality of receipt notices (one each time a copy is delivered to the user). While such techniques may be simpler to support in the chat server complex  204 , they may require more communication resources.  
         [0056]    In the example of FIG. 11, each entry comprises an attachment indicator  1104 - 1105  that indicates if there is any attached content (e.g., documents, files, etc.) or transmitted speech available; the short name of the sender  705  or  803 , and at least part of the message content or text (all of the text if the text fits within 2-3 lines). Although not illustrated in FIG. 11, there may be other indicators present on an entry such as a locked entry indicator (i.e., indicates that an entry was saved in permanent storage  305  and will always appear in the chat history display until it is unlocked). Note that lesser amounts of information may be included in each entry of the display. For example, only the message content could be displayed without the short names of the senders.  
         [0057]    When an entry is highlighted  1106 , the plurality of nicknames  802  or  704  of the sender and the other recipients is placed in the title bar  1101 . If the list is too long, the contents of the title bar  401  scroll. Alternatively, short names or other symbols may be used in place of the nicknames in the title bar  1101 . As the user selects an entry  1106 , all related chat messages in the same thread are emphasized  1103  as well. Emphasis can be done by changing or annotating the related entries or changing unrelated entries (e.g., graying out the entries). If a selected entry is too long to be displayed in its entirety and is selected for a length of time, the contents of the entry can expand automatically to display the entire text content. In that case, when the user moves to another entry, the entry immediately shrinks back to fit within its originally allocated space of 2-3 lines of text. The actual number of allocated lines depends on the screen size. As new inbound chat messages  400  arrive, new entries are added automatically to the list, for example, at the bottom of the list. The bottom or buddy list entry  1107  is a special entry referencing the list of buddies currently selected in the buddy list display. The user can use the entry to start a new thread with the buddies. The bottom entry  1107  only appears when the user has selected buddies, and comprises an icon  1110  distinguishing the entry from other “regular” chat message entries. If the user selects the bottom entry  1107 , the list of buddies appears in the title bar  1101  in the same manner recipients are displayed when the “regular” entries of the chat history are highlighted.  
         [0058]    The left softkey label  1108  is “buddies”. Single-clicking or click-holding the left softkey switches the user to the buddy list display (see FIGS. 9 and 10). The right softkey label  1109  is “reply” if the highlighted entry is a chat message entry. Otherwise, it is labeled “write,” as before. Single-clicking the right softkey moves the user to a message editor display described in more detail with reference to FIG. 14. The target recipients of a message are either derived from the list of recipients of a chat message entry  1106  or those associated with the buddy list entry  1107 . In the case where the highlighted entry is a chat message entry  1106 , click-holding the right softkey presents the user options similar to those described in more detail with reference to FIG. 13. Otherwise, if the highlighted entry is the buddy list entry  1107 , a “send to all” action is indistinguishable from normal “reply to all action” of single-clicking. If the user pushes-to-talk, the target recipients are compiled (i.e., either the sender and recipients of the chat message entry  1106 , or the buddies of the buddy list entry  1107 ), the title bar is updated in a manner described in more detail with reference to FIG. 12, and the recording and transfer of a speech chat message begins.  
         [0059]    It should be noted, that if an inbound speech message arrives while the chat history display is not visible to the user, the received speech is queued up. In a current implementation, the most recently received speech message (or at least that portion that will fit in available memory) are queued at the receiving terminal. In an alternate embodiment, such queuing can occur at the server complex such that the recipient can request playback within a predetermined period of time. Further still, queuing could occur at both the terminal and the server-side such that playback may be requested from the server in the event that a given speech message is no longer available at the terminal. While the speech entry is the most recent speech entry, the associated speech remains queued and ready for automatic playback upon the user&#39;s return to the chat history display. When the user switches back to the chat history display, if the speech entry is visible on the screen, it is automatically played back. Only the last speech message received is automatically played back. The playback is abandoned if the user returned to the chat history to record and transmit a speech chat message.  
         [0060]    Unambiguous delivery of speech messages to the user is a problem when integrating multiple multi-modal threads of conversation into a single chat history. In the current art, it is difficult for a user to associate speech with a particular discussion threads. The system disclosed herein solves the association problem in two ways. First, as discussed above, each speech message leaves an entry on the display. The entries link to their corresponding threads and represents at least the sender and the list of other recipients of the message. This, however, is not sufficient in cases where the user is unable to view the display while listening to speech messages. For this reason, the system disclosed herein uses a second technique in conjunction with the first. Preferably, when a user selects a thread, all speech messages associated with the selected thread are played back to the user automatically, unless otherwise provisioned by the user. Any speech messages not belonging to the selected thread are not played back automatically. Instead, the mobile terminal  100  presents an audible signal to the user indicating that there is other incoming speech message(s) in other thread(s). The user at that point can chose to playback the message or request the system drop it. Irrespective of whether the incoming speech message is played, the text portion of the incoming speech message is presented on the display. This helps the user in the decision process of choosing to listen to the message or ignoring it. Further optimizations are possible. For example, the user can be given the option to drop the message. Any speech data being transmitted is then dropped and the server is notified that it can stop transmitting the remainder of the speech message and begin transmitting the next message in the queue (if one exists).  
         [0061]    The delivery techniques can be optimized. For example, the mobile terminal  100  may send a message to the chat server complex  204  whenever the user selects a thread. This allows the chat server complex  204  to suppress sending the speech components of the speech message not belonging to the selected thread until the user indicates he/she wants to listen to the speech. This minimizes sending large amounts of data to the mobile terminal  100  that may not be used.  
         [0062]    [0062]FIG. 12 illustrates the title bar of a chat history display when the user is recording and transmitting an outbound speech message. The title bar comprises a recording indicator  1201 ; the plurality of recipient nicknames  705  or  802  (which does not include the sender) and, optionally, a single label  1203  indicating to the user that he or she is talking to the identified recipients. If the list of recipients is too long, the list scrolls; however, the recording indicator  1201  remains fixed in position. There may be a delay between the times when the user pushes-to-talk requesting to record and transmit speech and when the system grants the user access to do so. Preferably, the recording indicator  1201  is an icon that changes its appearance (e.g., color or graphic symbol) to indicate when the user has and or loses speech recording/transmitting access. Shortly after the user releases the push-to-talk button  101 , the title bar reverts back to the normal title bar  1101  on the chat history display.  
         [0063]    [0063]FIG. 13 illustrates a detail view display of an inbound chat message  500 . The title bar  1301  comprises the sender&#39;s presence indicator  904 ; the sender&#39;s nickname  705  or  802 ; and optionally a time stamp (when the message was sent or received.) If the information in the title bar is too long, the nickname scrolls. In that case, the remaining indicators preferably remain fixed. The content region  1303  comprises an attachment indicator  1302  that notifies the user of the availability of attachments or speech; the full text of the message  1309 ; a separator  1304 ; and the plurality of entries representing other recipients (not including the sender or the receiver). In the example shown in FIG. 13, each entry comprises the user&#39;s nickname set  703 - 705  or  802 - 803 . Alternatively, each entry could comprise only some portion of the nickname set (either the nickname or short name) or some other type of display identifier. The left softkey label  606  is “cancel”. Single-clicking and click-holding the left softkey exits the display and restores the previous display. The right softkey label  607  is “write”. Single-clicking the right softkey moves the user to a message editor display described in more detail in FIG. 14. Click-holding the right softkey presents the user options such as playing back the available speech; viewing or storing available attachments; locking the entry in the chat history display; saving the inbound chat message in permanent storage  305 ; moving to the next or previous chat message, replaying to only the sender or one of the other recipients (i.e., initiating a new thread), and so on. If the user pushes-to-talk, the detail view display is exited. The user moves to the chat history and begins talking to the sender (unless the user is the sender) and all other recipients. Playback of any queued speech is abandoned in that case.  
         [0064]    [0064]FIG. 14 illustrates a text message editor display. In this embodiment, the title bar  1401  comprises a plurality of target recipient nicknames  704  or  802  and a single action label that indicates to the user that he or she is composing a message. The title bar  1401  scrolls if the contents are too long. A text entry area  1402  is provided below the title bar  1401  for composing text messages. The left softkey label  1404  is “cancel”. Single-clicking and click-holding the left softkey exits the display, preferably abandons the contents, and restores the previous display (except in the case where the previous display was a detail view display, in which case the detail view display&#39;s previous display is restored instead of the detail view display.) The right softkey label  1403  is “send”. Single-clicking the right softkey causes the software to build and send an outbound text message  400 . Click-holding the right softkey provides the user a set of options such as attachment of other content (e.g., ring tones, etc.), spell checking the message, displaying the full details of the recipients and so on. Preferably, if the user pushes-to-talk, the display is exited, its contents are abandoned; the user moves to the chat history and begins talking to selected recipients. Playback of any queued speech is also abandoned in that case.  
         [0065]    The present invention is not limited to multi-modal chatting between humans. Multi-modal chatting can include machines. There exists text-based chatting systems, such as those deployed by Active Buddy, Inc., that allow users to interact with inventive services in the network using a chat metaphor. Unlike these systems, however, the systems disclosed herein allow the chatting dialogue to use both text and speech. For example, a user wishing to get status on a delivery of a package may send a speech message to a package deliver service presence. The speech would include at least the package identifier. The automated response service, using speech recognition techniques known in the art, determines the user&#39;s request and composes a response. That response can be speech based (e.g., it may send a speech message indicating it wasn&#39;t able to understand the request,) or it can be textual (e.g., the list of details of the package in route to its destination.) The service subscribes to the user&#39;s presence. The service sends the results back to the user when it notices the users presence&#39;s status allows sending the details in the preferred format.  
         [0066]    The inventive systems also allow services to incorporate commands that can be fulfilled at either the mobile terminal  100  (e.g., initiate a phone call) or at the server complex  204  (possibly in conjunction with other services in the network), or some combination thereof. For example, an individual chatting with another user may at some point wish to initiate a phone conversation. Preferably, the user requests the server complex  204  to initiate a phone conversation by sending a command from the mobile terminal  100  to the server complex  204  comprising at least the information needed to establish a phone call between the sender and the target recipient. The server complex  204  initiates a request to a Voice Over IP (VoIP) telephony system. That system then establishes the closest telephony access points to the end points and sets up a call by calling back the sender and the target user routing the calls between those access point using such common protocol as Session Initiation Protocol (SIP) and Real-Time Transport Protocol (RTP). The system may use a chatting interface to collect and establish the details of the call (as described earlier) or it may collect the information and initiate a command using common techniques known to those with ordinary skill in the art. In an alternative embodiment, the server complex  204  sends a command back to the mobile terminal  100  comprising at least the target&#39;s phone number. The mobile terminal  100  then initiates a telephony call with the target. Conventional techniques may be used to establish a phone call at the mobile terminal  100 .  
         [0067]    The quality characteristics of connections over wireless data networks can change with time. For example, a mobile user can move into a no coverage area where the data connection is dropped. The connection can be re-established later when coverage is available again, however, in the process the mobile terminal  100  may acquire a new IP address. Consequently, the server complex  204  is left unable to forward messages to the mobile terminal  100 . To deal with this, the system disclosed herein uses a session identifier to describe the connection between a particular mobile terminal  100  and the server complex  204 . Whenever a mobile terminal re-establishes a connection (after losing it due to loss of coverage, as an example) the mobile terminal  100  re-uses the session id of the interrupted session. The server complex  204  then rebinds the new connection to the existing session. If the mobile terminal  100  does not reconnect within a given timeout period, the server complex  204  can terminate the session. Other events causing a disconnection can include a lost session termination command sent from the mobile terminal  100 , improper shut down of the chat application at the mobile terminal  100 , battery failure, and the like.  
         [0068]    Preferably, all routing that occurs within (or among) server complexes  204  is done using the session ids. A session id is preferably used instead of a client id because a user may choose to terminate a session and establish another. In this manner, all messages bound to the terminated session may be removed from the system. Only transactions associated the active sessions are maintained. Also, in a distributed server complex  204  environment where there are many message broadcasters  303  (i.e. physical server hosts), the client may attach to different hosts servers. Using session ids provides a simple means to find where the client is currently connected. In addition, on re-establishing a connection, the server complex  204  can use what is commonly known in the art as sticky load-balancing switches that direct a re-connecting client to physically re-establish its connection with its previous host server based on the session id (even in cases where the IP address of the mobile terminal  100  may have changed.)  
         [0069]    In addition, many wireless operator networks do not allow unsolicited network-initiated messages to reach the mobile terminal  100 . Network-initiated messages, as they pertains to the systems described herein are messages going from the server complex  204  toward the mobile terminal  100  that appear to the network operator as if it was unsolicited by the mobile terminal  100 . This is a common problem in chatting environments since a message broadcaster  303  commonly sends unsolicited inbound messages  500  to the recipients of a message. To overcome this, the system uses keep-alive strategies. These strategies vary depending on the data transfer protocol established between the particular mobile terminal  100  and the server complex  204 . The keep-alive strategies involve periodically sending a message from the mobile terminal  100  to the server complex  204 . The keep-alive message appears to the mobile network as a request. Subsequent messages sent back to the mobile terminal  100  can then be considered by the operator as responses to requests as long as the messages sent to the mobile terminal  100  originate from the same address the mobile terminal  100  sent the keep alive message to. The frequency of the keep-alive messages is a matter of design choice and transfer protocol used. When HTTP is used as the transfer protocol, the system uses a polling mechanism. Using this mechanism, the keep-alive message is sent frequently and acts as a poll to determine if there are any pending messages at the server complex. If there are pending messages, those messages are sent back as a response to the polling request. TCP and or UDP do not require a polling mechanism and can use keep-alive techniques, such as simply sending at least the session id in a message to the server complex  204  with a significantly longer time between messages. Sending keep-alive messages may be optimized. For instance, the keep-alive messages do not have to be sent when outbound messages  400  have been recently sent from the mobile terminal  100  to the server complex  204 .  
         [0070]    Preferably, all messages sent to the mobile terminal  100  from the server complex  204  go through the same router and possibly the same physical host server that the mobile terminal  100  attaches to in the server complex  204 . This ensures that the operators can treat the messages as responses to a mobile terminal&#39;s  100  requests. Other techniques to make traffic appear to originate from the same location, such as address mapping and the like can also be used by the system.  
         [0071]    In addition, keep-alive messages work in conjunction with other techniques described above to inform the chat server complex  204  if the address of the mobile terminal has changed. This is especially useful in cases where UDP is used as the transport protocol. On every keep-alive message sent, the server complex  204  notes the address of the mobile terminal  100 . If the address changed, the server complex  204  then rebinds the session id to the new address. As such, the keep-alive message may still benefit the system even if the operator does not block network-initiated messages.  
         [0072]    It is possible that the server complex  204  is unable to deliver a message to a mobile terminal  100  because it doesn&#39;t have the most up-to-date address—the address of the mobile terminal  100  may have changed before a keep-alive message is sent. In this situation, the system may, for example, hold on to the undelivered message for a period until the next keep-alive message arrives; it may drop the message and inform the sender that it failed to send the message; or it may send the message using some out-of-band mechanism, such as the out-of bad mechanism described in connection with FIG. 15.  
         [0073]    A problem in some currently deployed wireless packet data networks is communication channel resource contention. While a wireless data connection is established, some systems (e.g., CDMA&#39;s 1xRTT) can loose the capability to route telephony calls and other wireless related services to the mobile terminals  100 . As such, the keep-alive strategy used by the system described above can become problematic. To solve this problem, the preferred embodiment uses a back-off strategy that is based on predicting the user&#39;s involvement in the chatting service. The back-off strategy uses a dynamic timeout scheme. For example, when the mobile terminal  100  is presenting a chat history display where there are active updates (i.e., inbound messages  500 ) and the likelihood if participation is high, the length of timeout is significantly longer than when there are no updates or when the mobile terminal  100  is presenting a buddy list display and the likelihood pf participation is lower. The purpose of the timeout is to guard against cases where the user might have forgotten or otherwise inadvertently left the chatting application running preventing any incoming telephony calls or other communications from reaching the user. When a timeout occurs, the user is given the opportunity to continue the session. A prompt notifying the user that the connection between the mobile terminal  100  and the server complex  204  is about to be severed. The user can choose to cancel the action and keep the connection alive. Otherwise, if the user doesn&#39;t cancel within the allotted time to respond, the connection is automatically terminated. When the mobile terminal is disconnected, it can no longer receive chat messages through the previously established packet data connections.  
         [0074]    Alternative disconnect schemes can be used. For example, the chatting program running on the mobile terminal may choose to periodically reconnect with the server complex  204  to see if there are any messages pending delivery. If not, the chatting program on the mobile unit may automatically disconnect. Otherwise, the messages are delivered and the program updates the chat history display as described above and resumes operations until either the user terminates the session or a timeout occurs as described above.  
         [0075]    [0075]FIG. 15 illustrates how the overall system architecture of a wireless communication system comprising the elements described in FIG. 2 is extended to integrate with a legacy mobile terminal  1502 . Within the context of the systems described herein, a legacy mobile terminal  1502  is capable of transmitting and receiving at least text messages over some well-established conventional mechanism, such as Short Messaging Service (commonly referred to in the art as SMS messages or simply SMS.) However, unlike a mobile terminal  100 , the legacy mobile terminal  1501  lacks the elements required to communicate directly with the chat server complex  204  and or to directly participate in any chatting transactions described herein.  
         [0076]    To integrate a legacy terminal, the chat server complex  204  communicates with at least one SMS aggregator  1501  via the communication network  203  (such as the Internet or World Wide Web). The SMS aggregator  1501 , which can be a commercially-available device, comprises all those elements needed to allow entities that may not have any direct affiliation with wireless carriers to inject SMS messages into at least one wireless carrier network  202 . The SMS aggregator  1501  takes as input (via its interfaces to the communication network) a description of the SMS. The description comprises all the elements needed to send a message to the target mobile terminal  100 . The description comprising at least the originator&#39;s address, such as a mobile terminal&#39;s  100  address, or a special return address known as a short code or a long code, the destination address, such as a terminal  100  address, and the content of the message.  
         [0077]    The SMS aggregator  1501  communicates with the target operator via its wireless carrier network  202  interfaces and injects an SMS on behalf of the requester. In this system, the requestor is the chat server complex  204  or any agents acting on its behalf.  
         [0078]    The mobile terminal  100  allows a user to enter the address of a legacy mobile terminal  1502 . This can be done in an ad-hoc fashion where the user is prompted for the address at the time of creating the outbound message  400 . The address in this context is typically the telephone number of the mobile terminal  1502 . Alternatively, for a user frequently targeting a particular legacy mobile terminal  1502 , the system may provide that user means to build a buddy presence in the system comprising at least a presence data record  700  and a nickname data record  800 . Conventional data collection and construction methods for the processes of adding a legacy buddy or using ad-hoc addressing, can be employed.  
         [0079]    The legacy address, be it the actual address or a recipient&#39;s id of legacy buddy, can be used in the same manner as any other recipient id. It is placed in the list of recipient ids ( 403  and  502 ) in outbound messages  400  and inbound messages  500 . In the case where the actual address is used, the address presentation is usually distinguishable from non-legacy addresses. That allows the system to process the address in a different manner than the remaining recipient ids.  
         [0080]    The legacy address can be a part of a group communication with at least another legacy mobile terminal  1502  and at least another [non legacy] mobile terminal  100 . Alternatively, the legacy address can be the only address supplied in a one-to-one communication with the legacy terminal. The legacy address can be part of initiating a new thread of conversation, or it can be part of a reply to an existing thread.  
         [0081]    In the case of ad-hoc entry of legacy address, the system has to establish recipient fields ( 503 - 505 ) in inbound messages  500 . The system may place generic representation in these fields. For example, it can use the address as the recipient&#39;s name  503 . Where available, the system may query public address books to find the actual name. Other techniques may also be deployed. For example, in cases where the information is considered private and the system is not permitted to present it, the mobile terminal  100  (or the server complex  204 ) may replace the information with proxy representations.  
         [0082]    The outbound message  400  carrying a legacy address is sent to the message broadcaster  303  in the chat server complex  204 . The message broadcaster  303  detects the legacy address of the legacy mobile terminal  1502  (either the actual address or a reference to it using a legacy buddy recipient id). For each non-legacy mobile terminals  100 , the message broadcaster  303  builds inbound messages  500  as described above herein.  
         [0083]    For each of the target legacy terminals  1502 , the broadcaster  303  sends an SMS request to the SMS aggregator  1501 . To do this, the broadcaster  303  sets the originator address of the SMS request to the mobile address of the sender&#39;s mobile terminal  100  initiating the message. The SMS aggregator  1501  sends an SMS on behalf of the chat server complex  204  and the sending user to the legacy mobile terminal  1502 .  
         [0084]    The message sent to the legacy mobile terminal  1502  contains at least the original message. Other information can be included in the message. For example, the message may comprise the list of other recipients, the thread identification, the time of delivery, a service provider identity, an advertisement, or the like. In the case of a voice message that can not be delivered via the out-of-band messaging scheme, the chat server complex  204  can replace the voice content with textual content. Where speech-to-text service are available, the chat server complex  204  can place the derived text message whole or truncated. Otherwise, the chat server complex  204  can place a representation of the discussion. For example, it may drop the voice part and only send the text part similar to what is displayed on a chat history display when an inbound voice message is received.  
         [0085]    Once the SMS is delivered to the recipient&#39;s legacy mobile terminal  1502 , the SMS application native to the legacy mobile terminal  1502 , which typically resides in an application storage and is executed on a CPU within terminal  1502  intercepts the SMS and notifies the user allowing the user to read the contents of the message. The recipient may respond to the message using the SMS application on the legacy mobile terminal  1502 . In that case, the application builds a reply SMS that targets the sender using the originator address in the original inbound SMS that was supplied by the chat server complex  204 . In this situation, the message does not go back to the chat server complex  204 . Instead, the reply SMS goes directly to the target mobile terminal  100  via the wireless carrier&#39;s network  202 . When the response reaches the target mobile terminal  100 , the chat application, intercepts the message and displays it as part of the chat history display as described in FIG. 11) as inbound message.  
         [0086]    Some mobile terminals do not allow the chat application to access the out-of-band messaging system. In that case, the user would either have to respond using the native out-of-band application, move the message (in part or in whole) between the two applications, or otherwise manage the message in the application.  
         [0087]    Currently most SMS systems do not comprise the elements necessary to allow the chat server complex  204  to predictably embed any information that would manifest itself in an SMS response coming back from the legacy mobile terminal  1502  (such as a thread id, list of recipients, or the like.) As such, the reply SMS is not guaranteed to have any identification that would allow the chat application program on the mobile terminal  100  to bind the inbound message to an existing thread. As a result, the message may appear in the chat history display as a new message in a new thread. The client on the mobile terminal  100  under these conditions can generate the thread id on behalf of the legacy mobile terminal  1502 . In the event the user replies, the new message and the legacy mobile terminal&#39;s  1502  address (i.e., the originator address of the reply SMS address) are sent to the chat server complex  204 .  
         [0088]    In an alternate embodiment, the chat server complex  204  does not place the sender&#39;s mobile address as the SMS originator address as described in the preferred embodiment. Instead, the chat server complex  204  uses a long code or alternatively, a short code. In this case, the SMS reply from the legacy mobile terminal  1502  goes back to the server complex  204 . The chat server complex  204  can de-multiplex the messages from the legacy mobile terminals  1502  over of codes using various conventional techniques to bind a reply SMS to an existing thread. In this case, the message broadcaster  303  in the chat server complex&#39;s  204  can broadcast the message back to all the participants in the thread via the appropriate channels. For example, if another legacy mobile device was participating in the thread, the message broadcaster  303  could send the message via the SMS aggregator  1501  as described above herein.  
         [0089]    The legacy integration role of the message broadcaster  303  can be performed at the mobile terminal  100  instead of in the chat server complex  204 . In this case, the mobile terminal  100  does not use the SMS aggregator  1501 . Instead, the mobile terminal  100  could inject the SMS directly into at least one wireless carrier network  202  for each of the targeted legacy mobile terminal(s)  1502 .  
         [0090]    Other out-of-band communication mechanisms can be used such as email, Multimedia Messaging Services (MMS), or the like. In such cases, other gateway forms replace the SMS aggregator  1501 . Other delivery mechanisms may allow embedding other information in the reply message from the legacy terminal, further allowing the system to bind the replies to the existing threads.  
         [0091]    A problem confronted by some mobile terminals  100  is loss of application context when the user initiates another, non-chat application on the terminal  100 . For example, when a user on a mobile terminal  100  receives an incoming telephony call, the mobile terminal  100  may drop data connection resources, suspend or halt executing the chat program, and/or otherwise disable the chat application from communicating and fulfilling chat transactions with the chat server complex  204 . In this case, the user may shutdown the chat application when there is little perceived activity or the chatting program may disconnect automatically to free up resources, as described above herein. As such, what was once considered a valid mobile terminal  100  for chatting according to the systems disclosed herein may act in a manner indistinguishable from that of a legacy mobile terminal  1501 . The techniques that are described above as methods to integrate the chat environment with legacy mobile terminals  1502  can be applied in these situations as well. The out-of-band delivery of messages (via SMS for example) acts as a hailing to the user. It informs the recipient that a chat thread is in progress. The user may then choose to re-activate the chat program and resume the chat conversation. Alternatively, if resumption is not possible or convenient, the user may still chose to participate using the available out-of-band mechanism. In cases where the chatting application has access to the incoming out-of-band message, the chatting application on the mobile terminal  100  many extract the content and place them in the chat history display. It may also allow the recipient to reply to the sender. The reply may go back as an out-of-band message or it may go through the chatting system as an outbound message  500  band through the chat systems disclosed herein.  
         [0092]    The presence status  702  represented on the mobile terminal  100  by presence status indicators  904  and  911  describes what is referred to as availability. Availability in such contexts indicates that a user is able to receive inbound messages  500  (and optionally the type of inbound messages  500 .) A status that indicates lack of availability in such contexts presents the fact that a user is unable to receive inbound messages  500  (or a particular type thereof). As such, either the system will drop messages targeting the unavailable user, or it will store the messages for some time until the user is available again. For example, the system may always attempt to deliver the message (even to legacy mobile terminals  1502 ). In addition, the availability (as defined by the current art) of legacy mobile terminals  1502  may not be determinable. Furthermore, it could be argued that the usefulness of availability (as defined by the current art) is somewhat diminished in cases where the mobile terminal  100  (and  1502 ) accompany the user the majority of time.  
         [0093]    The presence status  702  can implement availability as defined above. In addition, the systems use presence status  702  and presence status indicators  904  and  911  to communicate other information, such as message delivery type. To accomplish this, the user on the mobile terminal  100  is presented with a representation of the means the system will likely use to deliver the message such as using in-band communications over the wireless packet data or through an out-of-band method such as SMS, email, or the like. It may also provide a representation of the subset or type of the messages that are likely be delivered. For example, an SMS-text-only representation can indicate that only the text portions of the message would likely be sent via SMS to the target recipient. As such, any attachments (e.g., pictures) as well as any speech components of outbound messages  400  would likely be dropped or otherwise not delivered to the target recipient. Such representation is better suited to the mobile user. For example, it may communicate to the user the cost associated with the delivery of the message, the expected delays, and or quality of service.  
         [0094]    What has been described above is merely illustrative of the application of the principles of the present invention. Other arrangements and methods can be implemented by those skilled in the art without departing from the spirit and scope of the present invention.