GB2322519A - Modular ADSI telephone - Google Patents

Abstract

A terminal, comprises a base module having at least one connector for coupling the base module to a telephone switching system or a server; and a receptacle for an enhancement module for the terminal which provides enhanced telephony features or functionality beyond that which is provided by the base module itself.

Description

SCREEN-BASED TELEPHONE SET FOR INTERACTIVE ENHANCED TELEPHONY SERVICE AND METHOD OF OPERATING SAME BY MICROPROCESSOR CONTROL BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to telephone sets in general, and in particular to electronic subscriber sets for both residential and business use. The telephone set is flexible, user responsive, microprocessor controlled with generic directory list memory accessed by the user via dialpad and softkeys, without the complication of a computer keyboard. More particularly, it relates to a set having a display screen and capable of user interaction by means of soft-keys the definition of which may be downloaded through a thereto connected central office (CO). The set, therefore, is configurable in a limited way to permit remote, but user friendly, operation for banking, shopping, or such other interactive services as may be offered and/or supported by telephone companies and their customers.

2. Prior Art of the Invention With the proliferation of call-waiting (CW) and calling-number identification (CNID) service, subscriber telephone sets have acquired modem1 data processing and display capability. Indeed, Motorola provides since 1992 a caller ID integrated circuit with on-chip ring detection under the description MC 145447 for use in telephones.

Furthermore, modem cental offices (CO) are capable of providing enhanced services, such as in United States patent 4,661,975 granted April 28, 1987 to S.M. Brecher for Enhanced Call-Waiting Service. The patent discloses a process for controlling a telephone switching system which gives a telephone customer alternative ways of handling an incoming call while that customer is engaged with an existing call. The conventional call-waiting process is modified by permitting the dual tone multifrequency buttons to be operated for a predetermined short interval after the callwaiting signal is given to the called customer responsive to the particular tone signals keyed. The switching system is enabled to send busy tone or a predetermined announcement to the calling party or to reroute the calling party to an alternate destination.

United States patent 4,879,743 granted November 7, 1989 to E.T.

Burke et al, on the other hand, discloses a sophisticated PBX system for use with adjuncts such as a programmable voice message system, and passes data messages to the adjunct via DTMF tones.

United States patent 4,924,496 granted May 8, 1990 to R. Figa et al discloses an automatic incoming telephone call number display system for detecting an incoming call and identifying the party associated with the incoming call number. The system includes a directory of telephone numbers and parties associated with those numbers. Circuitry detects the origin telephone number of an incoming telephone call and compares that number with numbers in the directory for identifying the calling party. A display permits the user to view the incoming call number and party associated with that number. The incoming telephone call number display system disclosed includes a liquid crystal display, an alpha keypad and a numeric keypad.

In United States patent application Serial No. 07/733,027 filed July 2211991 by G. Chaput et al, a method of transmitting data between a CO and a subscriber terminal is disclosed wherein data bursts may be transmitted to the terminal while off-hook, thus enabling the terminal to be in a data interactive mode at the same time while in voice communication mode.

In December, 1992 an industry-wide standard protocol for Analog Display Services Interface (ADSI) was completed by Bell Communications Research Inc. to serve as a standard for voice and display (data) information to be transmitted between subscriber terminals and telecommunications switches or servers over the existing copper telephone lines (loops). This standard protocol also defines the formats for the large scrollable displays and softkeys to support new enhanced, interactive, services.

SUMMARY OF THE INVENTION In order to fully utilize the enhanced services now available from telephone company central offices (COs), and yet to maintain user friendliness and ease of programming, the telephone set of the present invention utilizes uniquely structured microprocessor control of the telephone set operation. Such unique structure involves the use of a non-volatile memory (NVRAM) for storing telephone directory lists, redial lists, and the like, which is hierarchically organized beginning with the physical memory access by means of utility functions, and progressing to user friendly functions accomplished by hard/soft keys and display prompts.

The present invention provides an interactive subscriber terminal (telephone set) for supporting the above enhanced capabilities at the subscribers' homes or offices. This is achieved without having to memorise codes, or to listen to several voice prompts.

A relatively large scrollable display and context-sensitive softkeys provide an improved subscriber terminal for making full use of services typically provided by telephone operating companies, as well as for those services provided by enhanced service providers (ESP) delivering third party services and applications through the telephone network.

Enhanced service providers (ESPs) are the second major source of ADSI-based services. ESP applications are driven by information downloaded to the terminal from a server - for example, an interactive voice-response system located in a bank.

In the ESP market, ADSI capability opens the door to many potential display-based services, such as catalog shopping, home banking, entertainment reservations, and (combined with broadcast access) selection of pay television programs, as well as such information services as stock and weather reports.

The introduction of ADSI technology will offer ESPs substantial benefits. For example, it will: (a) Improve overall service by helping to strengthen relationships with existing users, and to enlist new ones by delivering dial-up services through the public telephone network to a broader base than is possible through private access; (b) Offer an additional service delivery vehicle, providing increased availability and cost benefits; and (c) Diiferentiate ESPs from competitors by providing services that are easier to use.

Now, with the present ADSI terminal, operating companies and ESPs can immediately and cost-effectively introduce ADSI capability and enhanced services across the network.

For example, operating companies can rapidly deploy ADSI-based services using their existing copper-based infra-structures (loops) and in-band signalling capabilities, thereby efficiently and cost-effectively evolving their networks to capitalize on the emerging enhanced services environment.

And, third parties can immediately deploy display-based enhanced services, such as home banking, by building on interactive voiceresponse systems already located in their premises.

Finally, ADSI services complement existing custom calling and custom local area signalling services (CLASS), also known as call management services (CMS).

To enable service providers to realize these benefits, the present and related inventions focus on three technology aspects: (i) The creation of new display-based features; (ii) The design of several signalling schemes, including a method for in- band data transmission to an off-hook telephone (above-mentioned), and a technique to enable switches and servers to alternately deliver voice and data information; and (iii) The development of a virtual subscriber terminal (also termed customer premises equipment (CPE)) interface, which supports a wide range of display sizes, softkeys, keypads, and scroll keys.

Among features of the present invention are three advanced display-based applications. They are visual screening list editing, network call logging, and deluxe spontaneous call waiting identification (DSCWID) (also known as calling identity delivery on call waiting, with disposition). These ADSI capabilities complement existing custom calling and CLASS/CMS services.

Visual screening list editing enables subscribers on their ADSI terminal, to create and modify service lists, and turn features on and off, without having to reprogram the features. Subscribers to future ESPbased stock-market or sports-reporting services, for example, could set up personal profiles tailored for receiving specific information. They could also modify these profiles easily on their own displays, without having to call a service provider.

Visual screening list editing will also allow users to view and edit directory numbers stored as lists in, for example, the 'DMS SuperNode' switch manufactured by Northern Telecom. By enabling subscribers to easily manipulate these lists to personalize their displays, this ADSI capability eliminates many of the difficulties associated with today's callscreening services which require users to follow voice prompts and memorize complicated codes to edit lists and access features.

By coupling visual screening list editing with CLASS/CMS call screening features which include call waiting, selective call rejection, selective call forwarding, distinctive ringing, and selective call acceptance - subscribers can isolate certain incoming calls for special treatment, providing a measure of call-management control.

Network call logging assists in call completion by storing in a switch database (instead of in the terminal) the names and numbers of callers, as well as the times and dates of calls that arrive when subscribers are on the telephone or are not answering. Logging calls on the switch enables users to respond, with a press of a button, to calls (such as forwarded calls) that have not been displayed or logged by their own telephones.

Deluxe spontaneous call waiting identification (DSCWID) improves on the existing audible-tone-based call waiting feature by visually displaying the calling name and/or number of a second call during an ongoing telephone conversation. In addition, DSCWID gives recipients several softkey-driven ways of responding to the waiting party.

Depending on the importance or the desirability of calls, subscribers can: - Redirect waiting parties to a voice-mail service; - Activate a "busy" message if the ongoing call is more important than the new call; - Provide a "please hold" message, if the ongoing conversation is nearing completion; - Answer the second call and toggle back and forth, for example, to relay information between callers; or - End the first conversation and immediately connect to an urgent incoming call.

In order to support the above and similar features, the heretofore - mentioned in-band data transmission to a terminal, and dual-mode signalling, were developed.

In-band data transmission to an off-hook telephone, enables the switch to update the terminal's display with the call identification of a second incoming call or with ADSI service information.

Dual-mode signalling techniques enable the CO switch to alternately deliver voice or data information to an ADSI terminal across the conventional copper telephone lines.

Using in-band signalling, ADSI information (such as application and softkey definition data) is transmitted at a rate of 1200 bits per second, using the same type of signal that provides calling line identification.

However, existing CLASS/CMS services transfer information only when handsets are on-hook because they are not designed to temporarily interrupt the voice path during data transmission. If data transmission were attempted without muting the voice path, the data would be corrupted by the user's speech and the burst would be loud enough to cause the user discomfort. Therefore, transmission to the other party is muted before the subscriber's display is updated. This interruption prevents either party from hearing the modem burst.

The ADSI protocol enables the switch to first send a signal to the terminal, alerting it that the burst is coming. In the ADSI standard, this signal is composed of two tones - 2130 Hertz (Hz) and 2750 Hz transmitted simultaneously for 80 milliseconds. These frequencies can be isolated from voice because they are not among those generated by the dialpad, and do not occur frequently in conversation.

Dual-mode signalling enables ADSI telephones to receive many types of information including display prompts, voice prompts and greetings, and data for enhanced telephony features, third-party applications, and softkeys. This is accomplished by providing two modes of operation; voice and data. The voice mode is optimised for services that use both audio and visual prompts, such as those supported by interactive voice-response systems. The data mode, on the other hand, - is used for portions of applications where only data is displayed - for example, when a weather report service sends forecasts to a subscriber.

Because enhanced services can deliver many different types of data, the ADSI protocol allows multiple messages to be sent in the same data burst through the use of an encoding scheme similar to that used in calling line identification signalling.

A third mode, called feature down-loading, operates when the telephone is on-hook. This mode is similar to the data mode, except that it includes a mechanism for accessing the subscriber's display without ringing the telephone. Stored in the terminal, the information can be read by subscribers at their leisure.

The virtual CPE concept - which supports a range of display sizes, softkeys, keypads and scroll keys-provides multivendor capability by maintaining a generic interface to the network and servers. After a service writes display or command software to this generic display area, the ADSI protocol maps this information onto the actual telephone display. The ADSI protocol requires that all ADSI terminals adhere to this same virtual interface. This will allow various vendors to design terminals with different display sizes, yet support the same services.

The ADSI virtual CPE consists of three components: a virtual display, a virtual softkey table, and terminal control functionality.

The virtual display includes two pages: an information page and a communication page. The information page - two columns, 20 characters wide by 33 lines deep allows the terminal to store a block of data, such as callers' names and numbers, for the user to scan. The communication page (the same width by four lines deep) stores transient messages, such as prompts. This page is implemented separately to avoid overwriting the service-specific information page with procedural data.

Information for these two virtual pages can be downloaded to the telephone in a single transmission burst. The pages can then be partitioned in the terminal to suit the physical display. In the present preferred ADSI terminal, for example, the pages are partitioned to fit its 20-character-wide screen. In addition, the virtual pages can be divided vertically into multiple display "windows" on the actual terminal.

The virtual softkey table stores softkeys separately from the virtual display information. This table provides, on a per-session basis, a pool of 32 redefineable softkeys for each service. In the table, six softkeys can be assigned for each display line, and no two lines are required to have the same softkey. This flexibility allows the softkeys to be contextsensitive. The virtual softkey table contains: - A softkey definer - a single number that provides an index to the softkey table; - Softkey labels - such as erase, exit and dial - which are ASCII character fields that provide visual descriptions of the current softkey function; and - A return string, which is an ASCII character field acted upon when a softkey is pressed, indicating the terminal's response, such as on-hook, flash, dial-tone detect, or dual-tone multifrequency dial.

Terminal control functionality is composed of physical and display control functions. The physical control function disables and enables the handset, keypad, and softkeys. The display control functions determine the information to be shown, and how it should be displayed. For example, the cursor control function can move the characters on the screen from left to right, or in the reverse direction.

Accordingly, the present invention provides a modular telephone terminal, comprising: a base module having at least one connector for coupling the base module to a telephone or a server; and an enhancement module providing the terminal with enhanced telephony features or functionality beyond that which is provided by the base module itself; wherein the base module and the enhancement module are separate modules, but are plugged into one another.

Further, the present invention provides a terminal, comprising: a base module having at least one connector for coupling the base module to a telephone switching system or a server; and a receptacle for an enhancement module for the terminal which provides enhanced telephony features or functionality beyond that which is provided by the base module itself.

Further, the present invention provides a telephone terminal module which is pluggable into the base of a telephone terminal so as to provide the terminal with additional functionality not provided by the base itself, which module has a connector for enabling it to be pluggable into the base and thereby by physically a part of the terminal.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiments of the present invention will now be described in detail in conjunction with the drawings, in which: Figure 1 is a high level circuit block schematic of a telephone set according to the present invention; Figure 2 is a block schematic illustrating the method of carrying out the method of the present invention in the telephone set of Figure I; Figure 3 is a schematic showing the internal organization of the NVRAM 20 memory shown in Figure 2; Figure 4 is a schematic showing components of the telephone for use in a redial directory list; Figures 5a and 5b illustrate the manner of operation of the redial directory list; and Figure 6 is a flow diagram illustrating the operation of telephone directory list using the same generic memory organization; Figure 7 is a block schematic of an ADSI subscriber terminal according to the present invention; Figure 8 is a pictorial drawing depicting the front of the subscriber terminal as accessed by a user; Figure 9 is a diagrammatic summary of state machine (SM) interactions underlying the ADSI terminal and telephone network interactions; Figure 10 is a flow-chart defining the three modes of control of the display and softkeys of the ADSI terminal; Figure 11 is a pictorial of the front of the plug-in module of the ADSI terminal depicting it in use when in an interactive session; Figure 12 is a perspective view of the terminal during interchange of plug-in modules; Figure 13 is a flow-chart showing how the subscriber terminal handles an incoming call; Figure 14 is a flow-chart showing how the subscriber terminal handles user initiated action; Figure 15 is a flow-chart showing how the subscriber terminal handles incoming or user initiated activity while the terminal is active offhook; Figure 16 is a flow-chart showing how the subscriber terminal handles call-waiting routines; Figure 17 is a flow-chart showing how the subscriber terminal controls its internal directories; Figure 18 is a flow-chart showing how the subscriber terminal controls its internal "Callers" directory; Figure 19 is a flow-chart showing how the subscriber terminal interacts with a user to manipulate an internal directory; Figure 20 is an organizational chart showing the internal options directory of the subscriber terminal; Figure 21 is a flow-chart showing the "Redial" subroutine; Figure 22 is a flow-chart showing the "Services" directory subroutine; and Figure 23 is a flow-chart showing the "Copy" subroutine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figure 1 of the drawings, the telephone set of the preferred embodiment comprises at least one telephone line 10 (connecting it to the central office CO, not shown) connected to a line circuit 11 and a calling line identification device (CLID) 12. The line circuit 11 is connected to a DTMF dial pad 13, and communicates bidirectionally with a coder/decoder (CODEC) 14, which communicates with a handset 15 via an analog interface 16. The CODEC 14 also communicates with a microcomputer 17, which scans the keys of keyboard 18 of the telephone, and controls an LCD display 19. The microcomputer 17 reads and writes a non-volatile RAM (NVRAM) 20, as well as a static RAM 21.

Referring to Figure 2, it shows the NVRAM 20 and how it is managed to yield the generic directory link list memory. The object of the generic list memory design is to provide a logical system that structures the external memory NVRAM 20 storage in form suitable to functionalities required by various features in the telephone. To achieve this object the hard- and firmware are partitioned into five levels. The very bottom level, of course, is the NVRAM 20 itself, with the next higher level 22 consisting of utility functions that provide direct physical access to the NVRAM 20. On top of this level there is the lowest logical level 23.

Functions at this level are allowed to access the NVRAM 20 locations, but only based on logical specifications rather than on physical ones.

Also, this level provides automatic conversion between logical and physical descriptions of the NVRAM 20 locations. Primitives from this level support the whole design but they are not the user functions and there is no need to use them directly. Above, this level, there is a logical level 24, which is the first user accessible level. It gives the ability to access link list bytes based on purely logical identification record number/byte number within the record. The final level provides the user with several functions such as: - scroll up/down and left/right through the link lists, - bulk access to predefined fields, such as name and number, manage and maintain link list records, and initialize and verify link lists.

The NVRAM 20 is an external memory resource with 8Kb byte capacity. The NVRAM 20 is organised in 32 pages of 256 bytes in each page. Therefore, a particular byte in the NVRAM 20 is identified by an address composed of 5 bits for PAGE and 8 bits for OFFSET (8Kb = 8192 bytes = 25x28 = 32 pages x 256 bytes. This is the physical layout of the memory, and the utility level 22 provides access to the NVRAM 20. At the next level 23, the physical memory structure is converted into a logical layout by means of the link list concept. The record in the link list comprises the data area for storage information, and the linkage area to maintain certain relationships between records. For error protection the records are protected with record check sums. Further, the link list has a header part to keep general description/self maintenance information. The header is error protected with a header check sum. To be able to work with several different link lists located in different locations in the NVRAM 20 some global identification is needed. This identification simply determines where the particular link list begins in the NVRAM 20. The logical structure of the link list is shown in Figure 3, where the abbreviations mean the following: LNVRPAGA/LNVROFF- unique location in the NVRAM of particular link list (global identification by physical pointer like bytes) LCHKSUM header check sum byte LSELFLEN number of records in the link list LRECLEN number of bytes in the record's data area LUSEDREC number of records currently in use LUSEDF record number of the first record in use (logical pointer like byte) LUSEDL record number of the last record in use (logical pointer like byte) LLIMBO record number of the first record in limbo (logical pointer like byte) RCHKSUM record check sum byte RNEXT record number of the next logical record (logical pointer like byte) RPREV record number of the previous logical number (logical pointer like byte) To provide the higher level memory management system primitives are provided to access the memory on the lowest level. They are used to modify the NVRAM 20 address, to read a byte form NVRAM 20 and to write a byte into the NVRAM 20. These utilities are the black boxes from the perspective of the link list. It does not matter how address modifications, reads and writes are happening. Common ground for all utilities is the assumption that the NVRAM 20 addresses are always maintained in the processor's index registers. Index register X keeps the offset component of the NVRAM 20 address, and index register Y keeps the page component of the NVRAM 20 address. The NVRAM 20 address in the X, Y registers simply says which NVRAM 20 byte should be read or written, or which is the initial entry value for address modification action. There are two address modification functions: 1. INCADD - increments NVRAM address to the next byte.

Simply X register is incremented by 1. When address reaches the end of the page carry over increment takes place - X register becomes zero and the Y register is increment by 1.

This function does not use processor's Accumulator and just preserves its value over the function execution.

Example: Before call Acc = n Acc = m X = 32 X = 255 Y = 5 Y = 24 After call Acc = n Acc = m X = 33 X =O Y = 5 Y =25 2. ADCADD - moves NVRAM address ahead relative to the initial entry address specified in X, Y registers, by the number of bytes specified in Accumulator. Value provided in Accumulator is added into the X register in the carry over fashion. When carry over case takes place the Y register is incremented by 1.

Example: Before call Acc = 50 Acc = 12 X = 32 X = 245 Y = 5 Y = 24 After call Acc = 50 Acc = 12 X = 83 X = 2 Y = 5 Y = 25 NVRAM access functions are as follows: 1. RDNVR - reads the byte from NVRAM. Byte location in specified in the standard way in X, Y registers (OFFSET, PAGE respectively). After the function call the read in byte is placed in Accumulator and X, Y registers remain unchanged.

Example: Before call Acc = N/A X = 32 Y = 5 After call Acc = NVRAM byte from location 32/5 X = 32 Y = 5 2. WRNVR - writes the byte into NVRAM. Again the byte location is specified in the X, Y registers. Accumulator contains the byte value to be written into NVRAM and of course remains unchanged over the function call.

Example: Before call Acc = Some value X = 32 Y = 5 After call Acc = Some value X = 32 Y = 5 There is also a need for the utility type function (RUNCHKS) that calculates the check sum over N consecutive bytes in the NVRAM 20.

The RUNCHKS function adds up byte values from N consecutive locations in the NVRAM 20. The process starts at the location (OFFSET+ I) with carry/PAGE; where OFFSET and PAGE are provided in the XN registers, respectively. The number N of bytes to be included in the check sum calculation is provided in an Accumulator. The output value is a complement value of the calculated sum and is placed in Accumulator.

Example: Before call Acc = N X =O Y = 5 After call Acc = CheckSum X =O Y = 5 The above organization provides a generic way to manipulate any of the NVRAM 20 lists. It ensures that functions in the system are independent from the physical location of any particular list. However, since the logical operations take place in some physical location, it is the necessary to determine a physical point of reference. For this purpose two RAM bytes, LNVOFF and LNVRPAGE, are used as follows: Example: Set the reference to YOUR Link List LDM#YOUR~LIST OFF,LNVROFF ;offset component of the reference LDM#YOUR LIST PAGE,LNVRPAGE ;page component of the reference where Your Link List Address: #YOUR LIST OFF - value from 0 to 255 #YOUR LIST PAGE - value from 0 to 32 An example of a directory list is the redial list, which gives sequential access by scrolling to the last, say, five dialled telephone numbers. This feature is initiated by pressing the REDIAL key, which retrieves the first entry from the last numbers register (LNR) for display. - This feature will now be described with reference to Figures 4 and 5a and 5b.

The user may review all last numbers by pressing the RADIAL (or LNR) key and using UP and DOWN scroll keys. The numbers are displayed on the LCD screen and they may be re-dialled by pressing DIAL key.

The registers for last five numbers are doubly linked in a circular fashion. Each register contains a field for the dialled number, a field for the name (if name is supported), a field that contains the address of the next register, and a field that contains the address of the previous register. This is called a "Doubly buffer where it is used to drive a DTMF tone generator. As that number is dialled out, h is again collected in a buffer. At the termination of that call the same sequence of events described above will be followed. If the number dialled has not been changed (edited or digits added) it will fail the test for duplicates and the redial list will not be updated. If the number has been modified in any way it will pass the test for duplicates and will be placed into the Redial list.

The source code for the redial function is found in the APPENDIX hereto.

Similar to the redial lost function, Figure 6 shows a flow diagram of a telephone directory (list) function.

The directory list is a 64 entry (name and number), stored in the in non-volatile memory. Numbers can be added or deleted from the list, names can be attached or edited, and calls can be placed from the list.

The directory is accessed at any time by pressing a Directory hard key. If the terminal is off-hook, the current display will be over-written, but the call state will not be disrupted. To add entries, name and number can be saved into the directory from the display by pressing the SAVE key, e.g.

whenever there is caller ID information displayed. This applies to incoming or outgoing calls, call waiting calls, entries from the network caller's list, or entries from any other calling features.

The directory list is organised in a circular alphabetical order (scroll down for As, scroll up for Zs). Entries which have no attached name are listed in numerical order at the beginning of the list (before the As). The directory contents can be viewed by using the scroll keys and navigating one entry at a time. The dialpad provides a means of jumping down the list Pressing N6" once, for example will advance to the beginning of the M's. Pressing N6 a second time will advance the list to the N's. The scroll keys can still be used to locate a specific entry. To place a call to the entry currently displayed the user lifts the receiver or presses the DIAL key.

Referring now to Figure 7 of the drawings, describing a further preferred embodiment, it shows a block schematic of Analog Display Services Interface (ADSI) subscriber terminal 30, which comprises telephone (or terminal) base 31 and plug-in module 32. The base 31 connects to the TIP and RING of the telephone line connecting it to the central office (CO) of the telephone company. The base 31 comprises a line interface and electronic hook switch circuits 33, ring detector and alerter circuits 34, handset interface and analog-to-digital (A/D) convertor circuits 35, processor interface and EEPROM circuits 36, and standard touch-tone telephone keypad 37. A handset 38 is, of course, part of the standard telephone components of the base 31. The ADSI plug-in 32 comprises a data burst alert circuit 39, a microprocessor 40, a LCD display driver 41, a LCD display 42, softkeys (redefinable keys) 43 adjacent the display 42, and a printer (or printer port for an external printer) 44. Normally, the keys 43 will also include hard-keys such as scrolling cursor keys 45 and so on (as shown in Figure 8).

Referring also to Figure 8, it shows the user-visible front of the ADSI terminal 30. The module 32 plugs into the base 31 and connects to the latter by means of two buses 46 and 47, the former being the processor bus, and the latter for scanning the keys 43. The data burst alert 39, which comprises two switched-capacitor filters for detecting two pre-burst tones, receives signals through the interface 35 via connection 48. The sole function of the alert circuit 39 is to tell the processor 40 by means of hightone and low-tone leads 49 and 50 that a data burst will follow.

Turning now to Figures 9 and 10, the ADSl/Telephone Network interface layer is shown. There are four essential sub-systems: - ADSI/FDM (Feature Download Management) Command Processor; - ADSI User Interface State Machine (SM); - Softkey Return String (Script) Interpreter SM; and - FDM Service Script Interpreter SM.

The ADSI/FDM command processor accepts control events from the ADSI process layer, and is only required to update data structures and/or ADSI display components.

Examples of ADSI server and ADSI FDM commands are: - ADSI server: - Initialise softkey line - Line Control - Information - Disconnect Session - Switch to Data - Input Control - Switch to Peripheral - Load Default Softkey Tuple - Connect Session - Display Call Buffer - Clear the Screen - ADSI FDM: - Load CPE Script Softkey Table - Load Predefined Display - Load Script - Download Connect - Download Disconnect The ADSI User Interface state machine (UISM) processes all remaining events of interest, routing them as appropriate to the softkey script or service script interpreter state machines. It maintains some of the state information for each of the associated state machines, and coordinates any communications between them. An additional sub-task of this state machine is to provide a digit collector mechanism.

The UISM activates and modifies the softkey state machine (SKSM) by routing softkey or cursor events to it. Only one invocation of an SKSM will ever exist at any one time. Even when a sub-script is specified, it is not executed until after the current script has been completed. Practically speaking each invocation of the SKSM has a short life. It lives only until the end of the script or until the user goes onhook, with virtually every command being immediately executable. The only exception is "Dial Tone Detect", which has a 3 second time-out.

The FDM Service Script state machine (FSSM) is activated by softkey events when the FDM Ul state is active, as determined by the UISM. Network, timer, hookswitch and softkey script events may modify the sequence of a service script and the state of the FSSM. As with the SKSM, only the service script may be active at one time, however, many sub-scripts may be nested so the FSSM must maintain state information for every level of sub-script.

The ADSI terminal user interface is always under the control of the ADSI server application. In general the terminal is not required to interpret user actions. When in an ADSI session, the terminal display is modified either by direct commands from the server, or through predefined softkey return string instruction sequences or scripts. Scripts come in two types, softkey return strings and service scripts, both of which have previously been downloaded to the terminal.

Softkey scripts are executed by the softkey script interpreter, which, among other things controls the display components and network interfaces, and raises service script events. Softkey scripts Nn to completion and respond to no control stimulus other than a handset onhook event, which causes the script to abort.

Service scripts are executed whenever a user presses softkeys associated with one of the services presented the FDM (Feature Download Management) display. These scripts also control the display components and network interfaces as well as invoking subscripts, etc.

The state of the service script interpreter is controlled by physical events such as "caller ID received", "busy tone detected", "handset off-hook" etc.

In the course of using ADSI services, subscribers typically respond to prompting messages and control the flow of application information to their terminal displays by pressing softkeys. Softkeys change their function depending on the service requested. New functions are indicated by display-based (user friendly) labels downloaded from a switch or server either during or at the start of an interactive session.

Softkeys are stored separately from the ADSI information page in a virtual softkey table. This table provides, on a per-session basis, a pool of 32 redefinable softkeys for each service.

The virtual softkey table contains a softkey definer, which provides an index to the softkey table; softkey labels, which visually describe the current softkey function; and return strings, which indicate the terminal's response to the softkey. For example, by pressing a softkey labelled "Erase", the user could activate a dual-tone multifrequency 2 (DTMF 2, or touch-tone) signal to instruct the switch or server to delete a previously entered display line. Softkey labels are user comprehensible and must correspond to the following softkey return string command: COMMAND DESCRIPTION DTMF Transmit the characters using DTMF Encoded DTMF Transmit the following characters using DTMF encoding On Hook Open switch-hook Off Hook Close switch-hook Flash Flash switch-hook Dial Tone Detect Wait for dial tone detection (up to 3 seconds) Line Number Return current line number using encoded DTMF Blank Do not send anything back to server Send Characters Send the collected characters/ digits Clear Characters Clear the collected characters/ digits Backspace Erase the last character collected Tab Field Tab the current line to the following subfield Goto Line Goto the following page and line number Goto Line Relative Go up/down to the line relative to the current line Page Up Go up one page Page Down Go down one page Extended DTMF Send 250psec counts Delay Delay for the specified number of lOusec counts Dial Pulse One Send a dial pulse one Switch to Data Switch the terminal to Data mode Switch to Voice Switch the terminal to Voice mode Display Call Buffer Display the specified call buffer Clear Call Buffer Clear the specified call buffer Enable/Disable Flags Enable or Disable the specified information flags Clear Display Clear the terminal physical display Display String Display the specified predefined string Soft Key Display the specified softkey State Change Change the state of the active service script Timer Function Start or clear a timer Flag On/Off Turn a service script flag on or off Overlay Overlay the specified sub-script Event 22 Trigger Trigger service script event 22 Event 23 Trigger Trigger service script event 23 Exit Exit the service script interpreter Service script events are events such as "caller ID received", "timer expired", "extension telephone in use detected", "busy tone detected", and so forth.

Service slots which can be reversed for specific scripts via factory programming of the Feature Download Numbers (FDN) and security codes, as well as Services list locations, into module EEPROM. The factory programming also includes the capability to individually lock each script from being suspended (i.e. made nonexecutable) - Suspend bit, and individually lock each script from being deleted (i.e. overwritten by another script) - Lock bit.

Script state can be changed by the user (subject to factory programming of the suspend and lock bits) through the Services list. If there is no script loaded into a slot, the < available > prompt will be displayed in the Services list. When a script slot is empty, no other softkeys are displayed when the cursor is beside the < available > prompt.

A script that has been loaded but is not executable will be displayed in the Services list by showing the script name but not displaying a Select soft-key when the cursor is beside the script name.

This state occurs whenever factory programming of FDN &num; and Security code is done for a slot but no script has yet been downloaded, or when a script was executable but an error was found in the script when it was last executed. The following management soft-keys will appear beside the script name depending on factory programming: the Delete soft-key will appear if the script is deleteable (Lock bit not set) or suspendible (Suspend but not set); and, no soft-key will appear if both the Lock and Suspend bits are set.

A script that is executable by the Select soft-key (or by appropriate events/states for the Advanced Call Management Services (ACMS) and Display Based Marketing (DBM) scripts) will appear in the list as a Script name, with the Select soft-key visible when the cursor is beside the script name. The same management keys will appear as in the Loaded but not Executable state shown above.

A script that has been suspended from execution but cannot be deleted (lock bit factory programmed to not allow script to be deleted) will appear with < suspended > replacing the script name, with the Restore soft-key visible when the cursor is beside the < suspended > script prompt.

A script that has been suspended from execution and can be deleted (lock but not set) will appear with < deleted > replacing the script name, with the Restore soft-key visible when the cursor is beside the deleted > script prompt.

No script information is stored into memory until a valid FDM connect followed by data followed by a valid FDM disconnect is received by the V350. The user is given the option of accepting or rejecting the script download with soft-keys.

Updating a script means that a newer version of a portion or all of an existing script is to be downloaded to the phone. IF the FDN &num; and Security code match THEN any portion of a script which is downloaded (Script, Soft-keys, Displays) will replace the existing portion of the script.

This allows for "partial" downloads to be done where only 1 element of the script is updated.

Overwriting a script means that a different script will completely overwrite an existing script IF THE FDN &num; matches AND Security code does not match AND the script is currently in < deleted - state in the Services list THEN the script memory is cleared and the new script is overwritten into memory; and, an entire script consisting of Script, Softkeys and Displays must be downloaded or the script will not be executable. IF the FDN &num; does not match THEN look for an < empty > or < deleted > slot to overwrite the script into; the script memory is cleared and the new script is overwritten into memory; and, an entire script consisting of Script, Soft-keys and Displays must be downloaded or the script will not be executable.

A user initiated download will be refused IF the FDN &num; matches AND Security code does not match AND script is in either Executable state OR Suspended state; and, IF the FDN &num; does not match AND there are no < empty > or < deleted > slots. IF the FDN &num; and Security code match THEN allow partial download as in Outgoing call case. IF the FDN &num; and/or Security code do not match THEN refuse download.

A Telco script is one which starts automatically whenever the set receives an incoming call or initiates an out-going call. It is used to assist the customer with switch feature interactions such as DSCWID, Call Forwarding, 3-Way Calling etc. by providing context sensitive softkeys and display prompts.

Figure 11 illustrates the terminal in an interactive session with a stockbroker service provider. The ADSI protocol supports terminals of different manufacture and display sizes by maintaining a generic software "image" in the terminal memory. After a service writes information to this "virtual" display area, the ADSI protocol maps it onto the actual terminal display. Shown below is a typical virtual display information page - two columns of data, 33 lines deep. In this case, the data supports a stock-quotation service. Each column fits the screen of the ADSI terminal. The left column provides for menus and major service information; the right column supports additional stock-quotation information. Users can toggle between columns by pressing the terminal's left/right scroll buttons. To accommodate various service-list and menu depths, the columns can be divided horizontally into multiple - display "windows", which are separated by "breaks" programmed into the service. The display also contains softkey labels, which are downloaded from the switch or server to help users control lists and menus and activate services.

Virtual Display Information Page 1 Welcome to 2 Personal stock quote (Break) Select an action: 1. View portfolio 2. Browse market 3. View performance 4. Change portfolio 5. Request info.

6. Talk to broker 7. Change password (Break) Personal portfolio: Dated 08/22/94 Name: Close: +/-: '94 Low '94 High ABC Ltd. 34.8 - 0.2 28.7 35.5 Iso bank 21.6 + 1.3 20.2 21.7 Qcola 2.3 -7.9 2.3 28.1 (Break) Personal performance 1. Today's stats.

2. 1994's Stats.

3. Weekly Stats.

33 4. Total Stats.

Referring now to Figure 12, the modularity of the ADSI terminal separates telephone functionality into two units: a common base and a range of modules. Users will initially buy or lease a base and module can later alter or upgrade the telephone by replacing the existing module with a new one when additional functionality is required.

The approach will enable users who buy their telephones to protect their original investment in the base module. At the same time, it will give telecommunications operating companies and telephone retailers the flexibility to accommodate the substantial change and diversity that is occurring.

During the past few years, telephone operating companies have introduced a series of new, network-based services. The initial custom calling services can be accessed through traditional touch-tone telephones. Subsequent service releases, however, require improved terminals. For example, calling line identification - based on the Custom Local Area Signalling Services/Call Management Services (CLASS/CMS) protocol - delivers the caller's name and number to the display so that users can decide whether to answer the call. Unlike traditional telephones, CLASS/CMS terminals incorporate a display and an internal modem to enable reception of calling information from the switch.

ADSI services enable subscribers to access and control such services as home banking, and to interact with display and audio information from a switch or server.

In addition to this broad choice of new, enhanced network services and terminals, subscribers and service providers face a proliferation of other communications products, such as cordless telephones and telephone answering devices (TADs).

To compete successfully operating companies are seeking costeffective terminals to support the variety of new services now being introduced. Cost considerations are critical particularly in lease markets because operating companies must assume virtually all of the technology risk. Compared with consumers who buy terminals, leasers are less likely to retain their telephones because they do not have to make capital investments to replace them. Because operating companies assume the technology risk in a lease market, the impact of service and terminal evolution on consumers is minimal. The major issue for users is integrating the many available leased and retail products, such as telephones and answering machines, into one costeffective communications plafform.

Thus the present modular architecture enables consumers and telephone providers to evolve several distinct terminal types (such as cordless and TAD capabilities) and network service capabilities (such as custom-calling, CLASS/CMS, and ADSI) upon a single base. The common base provides mechanical and electrical components to support such fundamental telephony enablers as basic memory, dialpad, handset, handsfree speaker, and Hold and Link/Flash functions. This base provides a lasting plafform for a succession of service modules, which consumers can easily install by sliding them into place. Each module may deliver specific service capabilities.

Other modules may offer additional capabilities - for example: - Cordless access, providing the ability to handle calls from a personal cordless telephone anywhere in the house and yard; - Telephone answering device (TAD) capability, enabling subscribers to record voice messages from various callers; and - Two-line capability, aimed primarily at increasing the accessibility of small businesses.

Terminal providers can also use this modular approach to bring new products to market quickly because decoupling service modules from the base will enable manufacturers to deliver them more rapidly than was previously possible.

As may be seen in Figures 11 and 12, the ADSI terminal is organised so that subscribers can quickly and intuitively understand how it operates. The terminal is physically divided into two recognizable areas: one (located to the right of the terminal, near the display) for enhanced functions and controls, such as softkeys; and another (clustered to the left of the terminal) for basic telephony controls, like the touch-tone dialpad and volume control. The ADSI terminal's enhanced functionality is augmented by set-based features, which include the display and softkeys, a Directory, a Callers List, and a Redial List.

With reference to Figures 13 to 23 of the drawings, which are flow charts showing how the subscriber terminal 30 handles the various events, that are initiated by the user, or that are incoming over the telephone line. The terminal 30 may at any point in time be in one of four states, which are under the control of the flow-chart of Figure 10. The four states are: A: On Hook Idle; the terminal 30 is connected to the network, but there is no activity on the line.

B: On Hook Busy; there is an incoming call.

C: Off Hook Not Connected; the terminal 30 is off hook, and communication between the terminal 30 and the network is taking place in the form of a dial tone.

Off Hook Connected; there is a connected call between the terminal 30 and another terminal. There are three forms that the call can take: (i) a normal voice only telephone call (ii) an ADSI session between the user and a service, where the terminal 30 provides both a voice and display interface between the user and the service (iii) an FDM download from a service to the terminal 30.

Here, a service makes a connection to the terminal 30, but does not enable the ringer, or require the user to pick up the terminal 30. The terminal 30 downloads info on its own.

An incoming call takes precedence over an FDM download, which will abort, and may resume later when the terminal 30 is free again. All off hook activities are aborted by hanging up the terminal 30.

The ADSI terminal's liquid crystal display has a large screen (8 lines deep by 21 characters wide) that is ideal for viewing service lists and menus. A Contrast button enables users to optimize their view of the display. At the bottom of the display is an area for softkey labels, which are used in combination with six physical buttons located to the right and left of the screen. Softkeys give terminals great flexibility and functionality by decoupling the functions and labels from the terminal's physical controls, and moving them to the display. Each time the service progresses to a new stage, the displayed softkey functions can change.

Below the display are buttons that enable subscribers to access advanced services and call-management capabilities. Pressing the Services button, for example, gains access to such enhanced services as a home-shopping application provided by a third-party. To enable subscribers to keep records of their enhanced service transactions, a printer port is located to the underside of the terminal to support an optional printer.

The Directory is accessed by pressing the Directory button.

Directory item screens can be recognized easily because they are accompanied by a "card stack" icon. A letter of the alphabet may be displayed, which corresponds to the section of the directory the user is accessing. Subscribers can use the dialpad to enter this information, or they can simply press the Copy button to transfer the name and number of an incoming call from the display or the Callers List to the Directory.

The Callers List provides a record of the names and numbers of people who have called. Using the Options button, this feature can be set to record all calls, no calls, or only those that were not answered.

This list, which is accessed through the Callers button, is identified by an icon that looks like a person. When information about a new caller has been added to the list, the word "New" appears on the display the first time that entry is viewed.

The Redial List contains the (five) most recently dialed numbers and is accessed through the Redial button. The up-and-down scroll buttons are used to move the display window to select one of the five numbers. The right-and-left scroll buttons can be used to reveal long numbers that do not fit into the "window". The selected number can be dialed directly from the display by pressing a softkey.

In addition to enhanced service and call-management functions, the ADSI terminal provides a cluster of controls for more conventional telephony functions. These controls, such as a touch-tone dialpad and indicator lights, enable subscribers to easily use the terminal to handle telephone calls.

Near the handsfree speaker is a highly visible button that allows users to turn the handsfree feature on or mute the microphone, and an indicator lamp that shows when this feature is in use. Below the dialpad is a control that allows the user to adjust the volume of the ringer, handsfree speaker, and handset.

Although outgoing calls can be dialed manually by using the dialpad, the ADSI terminal allows calls to be initiated in other ways.

When a number from the Directory or the Callers List appears on the screen, for example, it can be dialed by lifting the handset, pressing the handsfree button, or using the Dial softkey shown on the display.

To the right of the handset is a light bar that is illuminated when an extension phone is picked up during a call, and flashes when the telephone rings or a call is placed on hold. This light bar also flashes when a new entry has been placed in the user's network-based voicemail service. At the same time, the phrase "Message Waiting" is displayed on the screen.

Above the dialpad are controls that enable users to Hold to call, Link or Flash to a waiting call, and release a completed call using the Goodbye button. Users can also personalise their terminals by pressing the Options button. The screen will then display the available options, which include the ability to: - Set the ringer to one of three distinct sounds; - Time the duration of calls - for example, to record the time spent talking to clients; - Modify the terminal's dialing operation; - Display information in English, French, or Spanish; - Set the time and data; - Program the Callers List to record all calls, no calls, or unanswered calls only; and - Display local calls without an area code, so they can be dialed without further change.

Figures 7 to 17, which show high-level flow-charts detailing the various steps of operation of the subscriber terminal in response to incoming signals or user initiated actions. The flow-charts contain descriptive narrative in the decision blocks, and are explicit and selfexplanatory. They are intended to complement the present detailed description.

Subscribers may personalize the ADSI terminal and use it easily and intuitively. By combining basic telephony functions with a large display and flexible softkeys, as well as voice, text, and icon-based graphic prompting and information capabilities, the ADSI terminal provides convenient access to enhanced services.

Claims (21)

1. A modular telephone terminal, comprising: a base module having at least one connector for coupling the base module to a telephone system or a server; and an enhancement module providing the terminal with enhanced telephony features or functionality beyond that which is provided by the base module itself; wherein the base module and the enhancement module are separate modules, but are plugged into one another.

2. The modular terminal as claimed in claim 1, wherein the terminal has a receptacle for holding the enhancement module.

3. The modular terminal as claimed in claim 2, wherein the receptacle is of a type in which the enhancement module can be slid in, thereby enabling the base module and the enhancement module to be plugged into one another.

4. The modular terminal as claimed in claim 3, wherein the base module and the enhancement module are adjacent to one another.

5. The modular telephone terminal as claimed in claim 2, wherein the enhancement module is a telephone answering device.

6. The modular telephone terminal as claimed in any preceding claim, wherein the enhancement module contains a display screen and a plurality of soft-keys.

7. The modular telephone terminal as claimed in claim 6, wherein the enhancement module is adapted for use in an ADSI session.

8. The modular telephone terminal as claimed in claim 1, wherein the base module is a corded telephone terminal and the enhancement module is a module which provides the terminal with cordless telephone capabilities, thereby enabling the terminal to be used with a cordless telephone associated with the enhancement module.

9. The modular telephone terminal as claimed in claim 1, wherein the enhancement module provides the terminal with an additional line capability.

10. The modular telephone terminal as claimed in claim 1, wherein the basic module is a single line telephone device, and the enhancement module provides the terminal with two line capabilities, wherein at least one line has ADSI capabilities.

11. A terminal, comprising: a base module having at least one connector for coupling the base module to a telephone switching system or a server; and a receptacle for an enhancement module for the terminal which provides enhanced telephony features or functionality beyond that which is provided by the base module itself.

12. The telephone terminal as claimed in claim 11, wherein the base module has a further connector for use in plugging the base module and enhancement module into one another.

13. The telephone terminal as claimed in claim 11, wherein the receptacle is of a type which allows the enhancement module to be slid into the terminal, thereby enabling the base module and the enhancement module to be plugged into one another.

14. A telephone terminal module which is pluggable into the base of a telephone terminal so as to provide the terminal with additional functionality not provided by the base itself, which module has a connector for enabling it to be pluggable into the base and thereby be physically a part of the terminal.

15. The telephone terminal module as claimed in claim 14, wherein the module contains a display screen and a plurality of softkeys.

16. The telephone terminal module as claimed in claim 15, wherein the module is adapted for use in an ADSI session.

17. The telephone terminal module as claimed in claim 14, wherein the module is a telephone answering device which physically fits within a receptacle of the terminal and is in an abutting relationship to the base.

18. The telephone terminal module as claimed in claim 14, wherein the base is a corded telephone terminal and the module is a module which provides the terminal with cordless telephone capabilities, thereby enabling the terminal to handle a call from a cordless telephone associated with the enhancement module.

19. The telephone terminal module as claimed in claim 14, wherein the module provides the terminal with additional line capabilities.

20. The telephone terminal module as claimed in claim 14, wherein the basic module is a single line telephone device, and the enhancement module provides the terminal with two line capabilities, wherein at least one line has ADS capabilities.

21. A telephone terminal or a telephone terminal module substantially as described herein with reference to the accompanying drawings.