Two-way wireless messaging system with transaction server

That which is claimed is:

1. A two-way messaging system, comprising:

a messaging network over which messages are sent;

a pager coupled to the messaging network via a downlink and an uplink;

said pager including a plurality of messages and corresponding message codes;

the pager sending an originating message code to the messaging network via the uplink;

said originating message code including a multiple message destination address that includes a plurality of destination addresses;

the messaging network including a plurality of messages and corresponding message codes that are identical to said messages and codes in said pager;

the messaging network expanding the originating message code into a message, and forwarding the message to each of the plurality of destination addresses;

a transaction server coupled to the messaging network, the transaction server opening a transaction for tracking each message sent over the messaging network corresponding to the message code from the pager to a message recipient, and closing the transaction for preventing further delivery of the message and a reply to the message after a service associated with the transaction is complete;

a conversation manager within the transaction server maintaining the transaction server in open and closed states;

a transaction manager within the transaction server communicating with the conversation manager and tracking a state of a message recipient involved with the transaction,

the transaction manager communicating with the conversation manager to close a transaction after the transaction manager determines that the transaction should be closed, thereby limiting replies from one or more of the plurality of destination addresses of the multiple message destination address.

2. The two-way messaging system according to claim 1, wherein the service associated with the transaction is receipt of a reply by the pager from each message recipient.

3. The two-way messaging system according to claim 1, wherein the service associated with the transaction is receipt of a reply by the pager from a predetermined number of message recipients.

4. The two-way messaging system according to claim 1, wherein the service associated with the transaction is complete when a predetermined amount of time expires after the message is sent to each message recipient.

5. The two-way messaging system according to claim 1, wherein the service associated with the transaction is complete based on a number of replies that are accepted for the transaction and a number of message recipients that have the closed state.

6. The two-way messaging system according to claim 1, wherein the messaging network is a wireless messaging network.

7. A two-way messaging system, comprising:

a messaging network over which messages are sent;

a pager coupled to the messaging network via a downlink and an uplink;

said pager including a plurality of messages and corresponding message codes;

the pager sending an originating message code to said messaging network via the uplink;

the originating message code including a multiple message destination address that includes a plurality of destination addresses;

the messaging network including a plurality of messages and corresponding message codes that are identical to said messages and codes in said pager;

the messaging network expanding the originating message code into a message, and forwarding the message to each of the plurality of destination addresses;

a transaction server coupled to the messaging network, the transaction server initializing at least one record for monitoring a service associated with each message sent over the messaging network corresponding to the message code from the pager to a message recipient, and deleting each record initialized for a message for preventing further delivery of the message and a reply to the message after the service associated with the message is complete;

a conversation manager within the transaction server maintaining the transaction server in open and closed states;

a transaction manager within the transaction server communicating with the conversation manager and tracking a state of a message recipient involved with the transaction,

the transaction manager communicating with the conversation manager to close a transaction after the transaction manager determines that the transaction should be closed, thereby limiting replies from one or more of the plurality of destination addresses of the multiple message destination address.

8. The two-way messaging system according to claim 7, wherein the service associated with the message is complete when a predetermined amount of time expires after the message is sent to each message recipient.

9. The two-way messaging system according to claim 8, wherein the predetermined amount of time is specified by the pager.

10. The two-way messaging system according to claim 7, wherein the service associated with the message is receipt of a reply by the pager from each message recipient.

11. The two-way messaging system according to claim 7, wherein the service associated with the message is receipt of a reply by the pager from a predetermined number of message recipients.

12. The two-way messaging system according to claim 7, wherein the service associated with the message includes one of an all-reply, an N-reply and a timed-reply.

13. The two-way messaging system according to claim 7, wherein the service associated with the message is complete based on a number of replies that are accepted for the transaction and a number of message recipients that have the closed state.

14. The two-way messaging system according to claim 7, wherein the messaging network is a wireless messaging network.

15. A two-way messaging system, comprising:

a messaging network having a first communication channel over which a subscriber to the messaging network receives a message from the messaging network and a second communication channel over which the subscriber sends a message to the messaging network;

a pager of said subscriber coupled to said messaging network via said first communication channel and said second communication channel;

said pager storing a plurality of predetermined messages and corresponding message codes;

said pager sending a message code to said messaging network;

a user agent coupled to the messaging network, the user agent storing a plurality of predetermined messages and corresponding message codes that are identical to said messages and codes in said pager, each predetermined message corresponding to a message code, the user agent receiving a message code from a subscriber of the messaging network and forwarding the predetermined message corresponding to the received message code to a message recipient over the messaging network; and

a transaction server coupled to the messaging network, the transaction server opening a transaction for tracking each message sent over the messaging network corresponding to the message code from the pager to a message recipient, and closing the transaction for preventing further delivery of the message and a reply to the message after a service associated with the transaction is complete;

a conversation manager within the transaction server maintaining the transaction server in open and closed states;

a transaction manager within the transaction server communicating with the conversation manager and tracking a state of a message recipient involved with the transaction,

the transaction manager communicating with the conversation manager to close a transaction after the transaction manager determines that the transaction should be closed, thereby limiting replies from one or more of the plurality of destination addresses of the multiple message destination address.

16. The two-way messaging system according to claim 15, wherein the service associated with the transaction is receipt of a reply by the pager from each message recipient.

17. The two-way messaging system according to claim 15, wherein the service associated with the transaction is receipt of a reply by the pager from a predetermined number of message recipients.

18. The two-way messaging system according to claim 15, wherein the service associated with the transaction is complete when a predetermined amount of time expires after the message is sent to each message recipient.

19. The two-way messaging system according to claim 18, wherein the predetermined amount of time is specified by the pager.

20. The two-way messaging system according to claim 15, wherein the service associated with the transaction is complete based on a number of replies that are accepted for the transaction and a number of message recipients that have the closed state.

21. The two-way messaging system according to claim 15, wherein the service associated with the transaction includes one of an all-reply, an N-reply and a timed-reply.

22. The two-way messaging system according to claim 15, wherein the messaging network is a wireless messaging network.

23. A method for two-way messaging, the method comprising the steps of:

storing a plurality of predetermined messages and corresponding message codes in a pager;

storing a plurality of predetermined messages and corresponding message codes that are identical to said messages and codes in said pager within a two-way messaging network, each of the plurality of predetermined messages corresponding to a message code selected by a subscriber of a two-way messaging network;

receiving a message code from the pager via an uplink;

expanding the message code received from the pager within the two-way messaging network to form the predetermined message corresponding to the received message code and a multiple message destination address that includes a plurality of destination addresses;

forwarding the predetermined message corresponding to the message code from the pager to a recipient at each of the plurality of destination addresses based on a content of the message code received from the pager;

opening a transaction for tracking a service between the pager sending the message code and each recipient;

closing the transaction for preventing further delivery of the predetermined message and a reply to the predetermined message after the service is complete; and

limiting replies from one or more of the plurality of destination addresses of the multiple message destination address.

24. The method according to claim 23, further comprising the step of maintaining the transaction open until a reply has been received by the pager from each message recipient.

25. The method according to claim 23, further comprising the step of maintaining the transaction open until a predetermined amount of time expires after the message is sent to each message recipient.

26. The method according to claim 23, further comprising the step of maintaining the transaction open until a predetermined number of message recipients receive the predetermined message.

27. The method according to claim 23, wherein the messaging network is a wireless messaging network.

28. The method according to claim 23, wherein the service is complete when a predetermined amount of time expires after the message is sent to each message recipient.

29. The method according to claim 28, wherein the predetermined amount of time is specified by the pager.

Description Submit all comments and votes

This application is related to commonly assigned, copending patent applications entitled Two-Way Wireless Messaging System and Two-Way Wireless Messaging System Having User Agent, both filed on Jul. 24, 1996, and incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

This invention relates to a two-way wireless messaging system having a transaction server for opening and tracking messages.

BACKGROUND OF THE INVENTION

Wireless messaging, such as wireless paging, is a popular consumer wireless service and will grow because of the availability of new narrowband Personal Communication Services (PCS) frequencies. Wireless communication and messaging provides the foundation for many different types of services. One popular service is one-way paging, which is now very successful. Its popularity has been contributed by numerous factors, including:

(1) the small form factor of the pager device, making it portable;

(2) the low cost of the paging service;

(3) easy maintenance of the pager device; and

(4) ease of use for both message senders and receivers.

One-way paging, however, has no reply capability A subscriber to a one-way paging service must rely on an alternate method to respond to any messages that are received. For example, after receiving a page from the one-way paging service, a subscriber often has to find a telephone and make a call to respond to the message.

Recently, some ideas have been proposed to design a "two-way paging system" while preserving the benefits of one-way paging, i.e., the small paging device, low cost service, easy maintenance and ease of use. These two-way paging systems include return channels, but they are used only for fixed and limited replies.

In commonly assigned, copending patent applications entitled Two-Way Wireless Messaging System and Two-Way Wireless Messaging System Having User Agent, both filed on Jul. 24, 1996, and incorporated herein by reference in their entirety, the disadvantages of the prior art wireless messaging systems are overcome through the use of a messaging network and two-way wireless messaging device which originates, receives and replies to messages having dynamic message components to and from the messaging network. It would be advantageous if transactions were open and closed at a point in time when a user decides if any further message delivery is necessary or desired.

SUMMARY OF THE INVENTION

In accordance with the present invention, a two-way wireless messaging system has a transaction server located within the messaging system for (a) opening and tracking messages among various users of the two-way messaging system and (b) closing a transaction to prevent further message delivery and replies after a predetermined transaction service is completed.

In one aspect of the present invention, a transaction remains open until a reply has been received by every intended message recipient. In another aspect of the present invention, a transaction remains open until a desired number of message recipients receive a message. In still another aspect of the present invention, a transaction remains open until a specified amount of time has expired.

In yet another aspect of the present invention, the transaction server includes a conversation manager for maintaining the transaction server in open and closed states. In the open state, replies to original messages are accepted and in the closed state replies are unaccepted. A transaction manager is in communication with the conversation manager and tracks the state of a message recipient involved with the transaction, and also communicates with the conversation manager for closing a transaction after the transaction manager has determined that a transaction should be closed.

The foregoing disclosure also discusses a two-way wireless messaging system that can be used also in a public switch telephone network or similar network.

Limitations of existing wireless paging systems are resolved and technical advances are achieved in the present invention by a method and system for transmitting messages on a wireless messaging network with a plurality of user agents and other intelligent servers such as transaction servers, distribution servers and batch servers. The benefits of the present invention are set forth below.

In accordance with one aspect of the present invention, a wireless messaging device can originate new messages or reply to previously received messages along a first communication channel (uplink), and receive messages along a second communication channel (downlink). Each such message is coded in a predetermined manner and includes, among other things, a message number that uniquely identifies a message stored both locally at the device and at the user agent, a modifier representing the customization to be applied to the message, and personalized address aliases.

A user agent inside the two-way messaging network, corresponding to a subscriber of a two-way message system, stores among other things, a plurality of messages and destination addresses. When a user agent receives a coded message from its associated subscriber, it expands the message back to the desired full message and destinations by selecting from the stored messages and destination addresses according to the code.

The message that can be transmitted is highly flexible. In addition to fixed pre-canned components, it can include dynamic components such as embedded replies, choices, predefined variables, etc. As an example, consider a stock trading application. A subscriber is notified via two-way messaging when a stock he or she is interested in has reached a particular value. The notification message can embed a reply with choices to buy or sell and predefined variables for entering the number of shares and share price.

The dynamic components allow customization of messages by message senders and recipients, thus greatly increasing the practical applicability of the system. The particular values of the dynamic components are encoded in the message modifier, and are recovered and applied by the user agent.

The coded message is much shorter than the corresponding full-text message, thus allowing reduced bandwidth usage in a wireless communication environment. Together with user agents, the use of coded message is especially suited for communication scenarios in which the bandwidth in the uplink and downlink directions are asymmetrical, or the end device is limited by processing power, memory storage, or battery capacity.

The two-way messaging system of the present invention also can support multicasting. A message can be forwarded to a plurality of destinations for multiple responses. The address alias contained in a coded message can correspond to a single address, a group address or any combination of the two. With multicast, the number of (uplink and downlink) messages required for the transmission of a message is minimized.

In another aspect of the present invention, the system can track and answer queries about transactions. A transaction is a single or a series of request-response interactions between a message sender and recipient(s). A transaction is most useful for communication scenarios in which selective responses are desired. For example, a transaction can specify that a response arriving beyond a certain time limit will not be needed and should be discarded by the system. When combined with multicast, a transaction can specify the desired semantics of the reply. For example, a transaction with ALL semantics specifies that responses from all recipients are desired, while a transaction with OR semantics specifies that a response from any of the recipients will close the transaction. Once a transaction is closed, additional responses will be discarded by the system.

In accordance with another aspect of the present invention, the system functionalities are distributed among a collection of user agents and intelligent servers. The distributed nature enhances the modularity of the system and makes possible the incremental deployment of the system. For example, a provider desiring only the functionalities of user agents but not those of the transaction servers need to only deploy the user agents.

The method and system of the present invention can be implemented on top of any two-way messaging transport. This includes dedicated paging networks (e.g., narrowband PCS), cellular short messaging service (e.g., IS-95, IS-136 and GSM), or wireless data transport (e.g., ARDIS).

The servers can be implemented on specialized network servers or intermediate switches.

The messaging device can be a dedicated paging device similar to existing alphanumeric pagers, a unit that attaches to a computing device (e.g., PDAs, laptops), or integrated as part of a communication device (e.g., cellular/PCS phones) or a computing device (e.g., PDAs, laptops).

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features and advantages of the present invention can be appreciated more fully from the following description, with references to the accompanying drawings in which:

FIG. 1 is a block schematic diagram of a system and method of the two-way wireless messaging system of the present invention showing its use in association with a public switched telephone network, data network, cellular network and a two-way messaging device.

FIG. 2 is another schematic diagram of the two-way wireless messaging system of the present invention.

FIG. 3 is a more detailed view of the two-way wireless messaging system showing various user agents, the messaging network, and examples of messages that can be forwarded among the different subscribers.

FIG. 4 is a schematic view showing the network architecture of the two-way wireless messaging system of the present invention.

FIG. 5 shows an example of the control architecture for the two-way wireless messaging system of the present invention.

FIG. 6 is a block diagram showing an example of the protocol architecture used between the messaging device and the batch server of the two-way wireless messaging system of the present invention.

FIG. 7 is a detailed flow chart showing an example of the protocol flow for new message delivery used with the two-way wireless messaging system of the present invention.

FIG. 8 is a detailed flow diagram showing an example of the reply delivery in the two-way wireless messaging system of the present invention.

FIG. 9 is a schematic diagram of a two-way messaging device in the form of a two-way pager that can be used with the two-way wireless messaging system of the present invention.

FIG. 10 is a schematic diagram of an example of the batch server structure that can be used with the two-way wireless messaging system of the present invention.

FIG. 11 is a schematic diagram showing an example of the functional parts of the user agent that can be used with the two-way wireless messaging system of the present invention.

FIG. 12 is a schematic diagram showing an example of the various functions of the transaction server that can be used with the two-way wireless messaging system of the present invention.

FIG. 12a depicts the open and closed states of the conversation manager.

FIG. 12b depicts the state transition diagram for the recipient states of the transaction server.

FIG. 13 shows a schematic illustration of a two-way messaging device where a simulated keyboard is displayed for entering a message.

FIG. 14 shows a simplified block diagram of various components of the two-way messaging cellular system specified by standards.

FIG. 15a shows the basic message flow in a conventional system upon registration of a mobile messaging entity.

FIG. 15b shows a flow diagram for message delivery to a mobile messaging entity.

FIG. 16 shows another simple block diagram of a two-way cellular messaging system having a user agent and transaction and distribution servers of the present invention.

FIG. 17a shows an example of the basic message flow in the system of the present invention.

FIG. 17b shows an example of the basic message flow for message delivery to a mobile messaging entity of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, there is shown at 10 a two-way wireless messaging system of the present invention, which allows an originating message code from a two-way messaging device 11 to be received in a user agent 12 of a two-way messaging network 14. The two-way messaging device 11 is illustrated throughout many of the drawings as a dedicated two-way pager. The two-way messaging device can also be an attachment to a communication device, or even integrated as part of a communication or computing device. A message can be delivered through a public switched telephone network 16 that includes a network access switch 18 connected to a telephone 22 by a first communication coupling 20 through a twisted pair line, co-axial cable, fiber optic line, wireless link or any other type of communication coupling. The messaging network 14 can also be connected to a cellular network 24 or data network 26 for transporting E-mail messages 27 to a desired destination such as a personal computer at a desired time. Additionally, messages could be forwarded to a destination through the world-wide web 27a.

In accordance with the present invention, a second communication coupling 28 connects the network access switch 18 to a Network Control Point (NCP) 30 that is coupled to a database 32 via a third communication coupling 36. The network 16 is coupled to the messaging network 14 via a fourth communication coupling 38. The communication coupling between the two-way messaging device 11 and two-way messaging network 14 is an air interface. The messaging network 14 also may have at least one user agent 12 corresponding to a subscriber 40 (FIG. 2) of the two-way wireless messaging service. The subscriber 40 receives a message from the messaging network 14 along a first communication channel 42. These messages can include transmitted messages or replies. Messages forwarded by the two-way messaging device 11 to the messaging network 14 are forwarded along a communication return channel 43. In the case in which messages and addresses of recipients are coded, messages received by the two-way messaging network 14 are forwarded to a user agent 12.

In accordance with the present invention, the user agent 12 includes a plurality of stored messages. A predetermined message is forwarded to a desired destination such as a data network 26, public switched telephone network 16 or a cellular network 24 in response to an originating message code that is received from a two-way messaging device 11 of the subscriber 40 along the second communication return channel 43. This originating message code is expanded by the user agent 12 so that the downlink message to the desired destination can include full information. Also, the selected destination could be a second two-way messaging device 44 (FIG. 1).

As shown in FIGS. 1 and 2, the services which can use the two-way wireless messaging system 10 vary, and can include services for sending messages to 1) a telephone 22, 2) a computer as E-Mail 27, and another second messaging device, such as a pager 44. The second communication return channel 43 used by the two-way messaging device 11 and any other device not only carries new messages or replies, but also enhances the system 10 capabilities. It can be used for acknowledgements, thus allowing reliable messaging, and for signaling such as registration or location information, if available. Because the message expands in the user agent 12, the channel bandwidth in the forward and reverse directions differs significantly, as much as a ratio of 100 (or more) to 1. This asymmetry also can exist in terms of processing power, memory storage and battery capacity between the messaging device 11 and the network 14.

For purposes of discussion, a short two-way messaging scenario is first described, followed by a more detailed description of various messaging system elements and their functions.

Referring now to FIG. 3, there is illustrated the two-way wireless messaging system having four user agents for Thomas, Dan, Mary and Paul, referred respectively as UAT 50, UAD 52, UAM 54 and UAP 56.

Thomas can originate through his pager 50a a message to his lunch group members, Dan, Mary and Paul, and inquire about lunch choices. The message is delivered via the two-way wireless messaging network 14 along message delivery channels 57a (air interface), 57b (Data network interface), 57c (telephone network interface) as a page to a two-way messaging device in the form of a pager 58 belonging to Dan, an electronic mail to a computer 60 belonging to Mary, and a phone call to telephone 62 belonging to Paul respectively. The reply from each recipient is collected by the two-way messaging network 14 along a respective message return communication channel 64a, b, c and forwarded back to Thomas via the first communication channel 42 as a page. The type of message return communication channel 64a, b, c and message delivery channels 57a, b, c vary depending on the device, such as a pager 58, computer 60 or phone 62.

In accordance with the present invention, the uplink messages are kept short because of the use of the user agents 50-56. The user agents mirror the state and context (e.g., any address and message tables in the user agent) of their messaging devices 11 (FIG. 1), 50a, 58. In the above example, the uplink message contains a short group identifier and a message number. These are used by the user agents as indices to respective data tables in message expansion. For message reply, the uplink message contains only a reply code. This is expanded back to the full reply inside the network. By using group addressing, Thomas sends only one message uplink and the network automatically "copies" the message to the multiple recipients at the predetermined destinations.

Dan, Mary and Paul each receive the message in a different format, which could have been proposed by Thomas during message origination or specified as part of the filtering/forwarding criteria of the respective user agents of the recipients.

The criteria for filtering/forwarding can be very general. It could be based on the message originator, time of day, or any other commonly available forwarding options. Messages can also be formed in a variety of techniques. For example, Thomas can send the message as a pre-canned message with an embedded response. Thus, the message would include not only the text of the request, but would also include a list of responses to be selected and returned by the recipient.

Any user agent, e.g., those depicted as items 50-56, typically maintains, among other things, an identical copy of the address and message tables as the messaging devices. The address and message information stored in the messaging device and respective user agent should always be consistent with each other. Typically, to change these address and message tables, a subscriber needs to change one copy first and the system will propagate the changes to the other.

There are various methods a subscriber to the messaging system can use to enter new messages or addresses. There are chiefly two main categories, i.e., through the messaging device itself, or through the messaging system.

For example, as illustrated in FIG. 13, the messaging device 11, e.g., a two-way pager, can include a simulated keyboard 69 displayed on the LCD screen 88. A subscriber uses the pager buttons 84 to navigate around the simulated keyboard and select characters to compose a message. This method is tedious and applicable more to short, fixed messages. This method is not practical for making flexible messages that contain dynamic components.

A subscriber can also elect to add an incoming message sent by others to its own set of messages. For example, the subscriber will receive an incoming message from another individual. The subscriber may like that particular message and through an appropriate selection of buttons on the messaging device 11, add that message to his or her own message list.

In still another method, many existing messaging devices such as pagers, have an input/output (i/o) port. This port could be used to connect to a laptop or a Personal Digital Assistant (PDA). A subscriber uses the laptop or PDA to edit messages and download them to the messaging device 11 via the input/output port. An appropriate protocol could be used.

The other major category is to use the messaging system for updating any new messages and addresses to the subscriber user agent. For example, new messages and addresses are directed to the user agent. This is one way to customize a subscriber's message and address set. The copy in the subscriber user agent is updated such as by using a dial-up program, an internet connection, a world-wide web page or even an operator to change the messages and addresses directly via wireline.

In still another method, the subscriber signs up for a new third-party service. When the subscriber initially signs for that service, the subscriber is given a set of messages and addresses that are used to access the service. These messages and addresses are then loaded directly into the subscriber's user agent by the service provider.

In the following, a more detailed description of a user agent 12 (FIG. 1) and its function relative to the two-way wireless messaging system 10 (FIG. 1) is set forth.

In accordance with the present invention, each subscriber of the two-way wireless messaging system 10 is represented by a user agent 12 that resides inside the messaging network 14. The user agent 12 expands coded originating messages received from a two-way messaging device and provides pointers to the last known location of the two-way messaging device 11. It also maintains the status of the two-way messaging device 11, i.e., if it is on-line, and a profile of the subscriber. The user agent 12 also can provide some value-added functions such as message screening and selective message forwarding. The user agent 12 may also be customized by its subscriber 40. Thus, the user agent 12 acts as a personal server for the subscriber 40.

The user agent 12 also provides other benefits. Because messages are expanded inside the messaging network 14, the bandwidth on the uplink can be reduced, allowing bandwidth asymmetry on the wireless link. By performing intelligent processing in the network instead of at the end device 11, the enhanced power of the network is utilized. The user agent 12 manages mobility by tracking the location of the subscriber. Finally, the user agent 12 serves as a proxy for the two-way messaging device 11 when it is out of range, allowing the system 10 to account for disconnected users.

As shown in FIG. 11, the user agent 12 can have respective fixed and extensible parts 70, 72. The fixed part 70 implements basic messaging functions that are generic for all user agents. It can mimic the context of a messaging device, (e.g., the address table and the message table) and maintains information about ongoing message delivery. The extensible part 72 includes user agent programs 72a, 72b, it can be programmed to perform specific tasks as desired by the subscriber 40 (FIG. 1), e.g., maintaining a personal calendar, retrieving specific information from a world wide web page 27a, a database 73, where data can be input 73a, or other similar functions. The software 74, is associated with the user agent program to provide run time support for the system.

These basic functions include registration/deregistration, message delivery and message status query.

In registration, the current location of the two-way messaging device is updated to the system as shown in FIG. 4. Registration can be explicit or implicit. Explicit registration occurs when a messaging device is powered-up or when it moves into a new cluster 78 (FIG. 4). Implicit registration occurs when a message is received or delivered to a messaging device. During power-up, the user agent 12 can also download messages that have been received in the messaging network 14 since the last power-down of the two-way messaging device.

The user agent 12 allows message delivery:

(1) when the device originates a new message;

(2) when the device receives a message;

(3) when the device replies to a message; and

(4) when the device receives a reply.

Processing for groups 3 and 4 closely resembles that of groups 1 and 2.

When a messaging device 11 originates a new message, the user agent 12 translates the destination and reply address aliases sent by the device into the full address and expands the supplied message number and modifier into full message text and creates a record for the message. This record can be used as a basis for any subsequent message query. When a messaging device 11 receives a message, the user agent 12 returns the current status (on/off) and location of its device. Certain personal messaging functions, e.g., forwarding or filtering can also be performed.

For message status query, the query request is answered by the user agent by consulting its message record and if necessary, a transaction server is consulted about current delivery status, as will be explained later.

The extensible portion of the user agent specifies a framework in which additional functions can be added as user agent program modules 72a, 72b (FIG. 11). This collection of programs contain codes to handle messages of a specific pattern. The extensible part 72 follows an event-driven model and provides a kernel that pattern-matches incoming messages and dispatches them to an appropriate program module. Also, the extensible part 72 can be used for signaling by addressing a message to the user agent itself. For example, a message status query can be implemented as a signaling function in the extensible part.

Referring now to FIG. 4, there is illustrated a basic architecture of the two-way wireless messaging system 10 of the present invention. As illustrated, the system 10 includes a three-tier hierarchy. The highest is a domain 80; the cluster 78 is the middle; and the cell 82 is the lowest. The coverage area of a base station 76 defines a cell 82. A collection of adjacent cells 82 form a cluster 78 and a collection of clusters form a domain 80. Three domains are illustrated. A domain 80 is an administrative unit and each subscriber is associated with a unique domain called the "home domain". The various servers of the present invention 10 are replicated in each domain 80 and the user agent of a subscriber resides and is managed by its home domain. For purposes of description only one single domain is described. This hierarchy is designed for several important principles in the present invention:

(1) limiting the control information transmission;

(2) limiting the size of transmitted messages; and

(3) distributing functions in a modular manner.

To limit the transmission of control information by a two-way messaging device 11, the amount of periodic signaling is reduced. For example, location updates can be minimized by defining the registration area to be a cluster 78. Thus, the two-way messaging device 11 only re-registers with the system 10 when it crosses cluster boundaries. This can reduce the amount of signaling traffic, especially in a microcell infrastructure with high subscriber mobility. Thus, the messaging network only knows the location of a messaging device to the resolution of a cluster 78, and a limited search is necessitated to locate a device 11 before message delivery.

A small cluster 78 size provides better precision of device location and a smaller messaging delay at the expense of more frequent updates. A larger cluster size, on the other hand, increases average messaging delay but requires less frequent updates. To obtain an optimal cluster size, both message arrival rate and mobility pattern should be considered.

Referring now to FIG. 9 there is illustrated one example of a messaging device that can be used with the present invention. It is illustrated as a dedicated, stand alone two-way pager 11. In this example, the messaging device 11 generates, receives and displays messages to the subscriber user. The design of the messaging devices must take into account important hardware limitations, such as the need for minimum power consumption. As illustrated, the messaging device 11 should be business card size to provide the portability required of "any time, anywhere" service. The power consumption should be minimum, requiring infrequent battery change.

FIG. 9 shows a representative schematic of a pager 11 having four function buttons 84 at the bottom serving as soft keys, i.e. keys whose functions vary with the contexts, and two buttons 86 on the side, used mainly for scrolling purposes. The two-way pager includes a 5-line LCD screen 88 in which the top four lines are used for text while the bottom line shows current bindings for soft keys. The pager contains computing hardware, e.g., a processor and memory for user interface code and pager protocol. A low power general purpose microprocessor can be used for the pager. Memory should be adequate enough to contain these various messages and associated data.

As shown in FIGS. 2 and 4, a base station 76 terminates the air interface and a link layer protocol with the pager 11. It manages the air interface resources. Base stations 76 can be deployed as cellular base stations, packet radios or other types of transceivers as required for any wireless messaging and paging systems.

Referring now to the general overview of FIGS. 4. and 5, there now follows a description of the various servers used with the two-way wireless messaging system of the present invention.

A batch server 100 provides intelligence to base stations 76. A single batch server 100 connects to one or more base stations 76, and receives and acknowledges messages from the messaging device 11. It also receives messages destined to a messaging device, forwards them to the proper base station 76 for delivery, and receives acknowledgements that the messages have been correctly received. The batch server 100 may batch downlink pages into groups for scheduled delivery to allow sleep mode operation of pagers. In essence, a batch server 100 acts as a point of transfer between the wired (network) and the wireless (subscriber and base station) portions of the system 10. It is responsible for relaying uplink messages from subscriber devices (via base station 76) to the network and downlink messages from the network to subscriber devices (via base stations 76).

A protocol structure that can be used for interactions between the pager 11, base station 76, and batch server 100 is shown in FIG. 6. The Message Layer Protocol (MLP) 102 is responsible for ensuring reliable message delivery between the batch server 100 and a messaging device. Each MLP 102 data unit contains one user-level message. At most one message per messaging device may be outstanding at a time. The sending entity of a message maintains a retransmission timer for the outstanding message, and retransmits the message until it receives an acknowledgement. Acknowledgments are generated by the receiving MLP entity when a message is correctly received.

The Airlink Specific Convergence Sublayer (ASCS) 104 operates peer-to-peer between the batch server 100 and the messaging device 11. The ASCS 104 is responsible for segmenting MLP 102 data units into the appropriate size for transmission over the air interface, and re-assembling air interface frames into MLP data units at the receiver. ASCS 104 passes only correctly received data units to an MLP; any corrupted data units are silently discarded. The ASCS protocol specification is dependent on the air interface protocol, and as a result, many different ASCS's will exist.

Two link layer protocols 106, 108 are illustrated. LINK1 106 operates between the batch server 100 and the base station 76. LINK2 108 operates over the air interface and is specified by the particular air interface used in the system 10.

The high-level structure of a batch server is shown in FIG. 10. It maintains a number of data structures for its operation such as a registered messaging device table, which maintains a record for each messaging device currently being served by the batch server. The record includes both information about the messaging device (i.e., last base station visited) as wel