■RADIOTELEPHONE DEVICE
Field of the Invention
This invention relates to the field of radiotelephones and to the provision of private branch exchange (PBX) and other functionality in telephones.
Background to the Invention
There is a need for a cheap and simple way to provide telephone communications in locations where there are no land lines or where it is inconvenient to provide land lines such as in temporary buildings on construction sites. It would be convenient to use the cellular GSM network for this purpose. Existing equipment such the Nokia 22 (trade mark) or Ericsson F200 (trade mark) fixed cellular terminal equipment. Each of these is designed as a 'back room' device, i.e. once the unit has been set up, it is hidden away in a convenient space or 'back room'. The Nokia product uses light emitting diodes (LEDs) as indicators for the infrequent installation procedure. A disadvantage of this design approach is that it is necessary to have access to a manual to interpret the various combinations of LEDs. Such a design represents the very opposite of user-friendliness. The Ericsson product has the option of adding a fax/data accessory (having the product name "FD10") with a LCD display. This accessory provides GSM modem functionality for general purpose data use.
There is a need for a short message service (SMS) from any such location that connects dual tone multi-frequency (DTMF) telephones to the GSM network.
There is also a need for a simple, cost-effective way of providing a method of connecting a telephone or PBX directly to the GSM network so that calls to mobile phones on the same network avoid the additional charge of using the land line public switched telephone network (PSTN).
Summary of the Invention
According to a first aspect of the invention, a radiotelephone device is provided having an interface for connecting to a telephone apparatus for receiving signals (e.g. DTMF signals) generated from a keypad of the telephone apparatus. The device comprises a decoder for decoding signals received from the telephone apparatus, a display arranged to display menu items and a controller coupled to the display and the decoder for causing the display to display selected menu items in response to signals received from the telephone apparatus.
A radiotelephone module is preferably coupled to the controller for receiving control signals from the controller and coupled to the interface for communicating audio signals to and from the telephone apparatus.
Signals corresponding to selected keys of a telephone keypad can be decoded as navigation commands to navigate through menu items. In response to a navigation command, the controller can cause a different menu item to be displayed on the display.
A write-send option is preferably included in the menu items, and the controller is preferably arranged to switch from a navigation mode in which selected telephone keypad signals (e.g. signals equating to the keys "*", "0" and "#") are interpreted as navigation commands to navigate between menu items and a write-send mode in which the same keypad signals are interpreted for message content generation. A signal equating to the key "0" ("zero") may be interpreted as "select" when in navigation mode, but interpreted as zero or space when in write-send mode.
Thus, a radiotelephone device is provided which, in combination with a standard DTMF touch tone phone, provides a cellular terminal with a display .to compose, send and receive text messages. A design for a fixed cellular terminal is set out in greater detail below which, when used with an ordinary telephone, gives all of the features of a handheld cellular terminal. Such a product can considerably increase the usage of fixed cellular terminals (FCTs). It is easy to set up and use, and with this
product all kinds of new applications become possible. The availability of such devices and multi-SIM tariffs could eliminate the need for land lines in the home and office.
Brief Description of the Drawings
Figure 1 is a functional block diagram of a radiotelephone terminal device in accordance with the present invention.
Figure 2 is a software state diagram illustrating different software processes implemented by the microcontroller of Figure 1 and illustrating state transitions between these different software processes.
Figure 3 is a display diagram giving an example of information displayed on the device of Figure 1.
Detailed Description of the Preferred Embodiment
Referring to Figure 1, a radiotelephone terminal device 10 is illustrated connected to a telephone apparatus 11 via a telephone cord 12. The telephone apparatus, which could optionally be a private branch exchange (PBX), 11 has a handset 13 and a keypad 14 and (optionally) a display 15. The telephone apparatus 11 is connected to the device 10 by a standard multipin plug-and-socket connector that is readily connected and disconnected by a user.
The radiotelephone terminal device 10 comprises a microcontroller 20, a GSM radiotelephone module 22, a subscriber line interface card (SLIC) 24, a dual tone multi- frequency (DFMF) decoder and tone generator 26, a liquid crystal display (LCD) 28, a connector (for example an RS232 connector) 30 and an audio amplifier 32. The device is powered from a 12 volt mains adaptor (not shown) or by a suitable battery.
The microcontroller 20 is a highly integrated device that comprises a central processing unit (CPU), Random Access Memory (RAM), Read-Only Memory (ROM),
serial interfaces 41 and 42, a timer 44, analogue inputs and digital inputs and outputs 46, 47 and 48. The microcontroller 20 stores and runs the program code that provides a user interface (UI) and operating functions of the radiotelephone device 10. The radiotelephone module 22 is preferably a dual band TC35 GSM module, available from Siemens GmbH. It has a serial interface 50 connected to one of the serial interfaces 41 of the microcontroller 20 and it has an analogue audio connection 52 to the SLIC 24 via the amplifier 22 and it has a connector to a subscriber identity module (SIM) 54. The SLIC 24 provides battery feed, over-voltage protection, ringing, supervision, hybrid and test functions for the telephone interface 12. It accepts control information from the microcontroller via control line 56 and provides indications of on/off hook status to input/output 46 of the microcontroller. Analogue audio is connected from the SLIC via amplifier 32 to the radiotelephone module 22. The DTMF decoder and coding generator 26 detects sixteen standard DTMF codes, twelve of which are used on a standard telephone apparatus. The presence and time of tone detected is communicated to the microcontroller 20 via the serial interface 42. The DTMF decoder and tone generator 26 also generates tones and FSK that is used for CLIP. The LCD 28 connected to output 48 of the microcontroller provides the user with status information of the terminal and visual feedback of the UI. The RS232 connector 30 provides data and control signals at various levels and operates as data communications equipment (DCE).
Functions of the device 10 are controlled by the microcontroller 20 and the code that resides therein. At power-up, the GSM module 22 is started up and configured. The GSM module attempts to register with the GSM network to be ready to make or receive calls. If a call is received at the terminal, the GSM module 22 indicates this by sending serial information to the microcontroller 20 via ports 50 and 41. This in turn causes the microcontroller 20 to output status information on the LCD 28 and to generate a telephone ringing signal by control line 56 and SLIC 24. This causes the telephone apparatus 11 (if connected) to ring. If the handset 13 is taken off the hook, a call will be connected and an audio line established between the telephone apparatus 11 and GSM module 22 via amplifier 32.
When the GSM module 22 is in idle condition (there is no incoming call), lifting of the receiver 13 off hook delivers an off-hook signal to the SLIC 24 which initiates the UI function in microcontroller 20. This is described in greater detail below. A dial tone is sent by SLIC 24 to the telephone apparatus 11 , and visual instructions are provided on the LCD 28. As the user presses keys on the telephone keypad 14, the LCD shows feedback depending on the function selected.
Referring to Figure 2, a software program flow diagram is given, illustrating the structure and flow of the UI software stored and run by the microcontroller 20.
At the highest level of the UI software is a main menu routine 100. When this routine is running, the UI is in the main menu mode and one or more of six menu options are displayed (depending on the display space available on LCD 28). The menu options at this level are: phone book, messages, call register, call divert, settings and clock. More or fewer options can be given. For each option, there is a corresponding sub-program 101-106 respectively.
A selectable option is displayed on LCD 28 (e.g. by means of a cursor or other indicator for highlighting a selectable option, or by scrolling the options so that the selectable one is the only one displayed or is at the top of the list). To select the indicated option, the user presses the "0" (zero) key on the keypad 14. This causes the corresponding tone to be sent to the DTMF decoder and generator 26 where the symbol is decoded and delivered to the microcontroller 20. Receipt of that code by the microcontroller causes it to navigate to the selected program 101-106. If a different program is desired, the user presses the "#" key ("hash" or "square" in UK or "pound" in US) and this causes a scroll operation within main menu program 100, which causes the next selectable option to be indicated on display 28. On a 2 X 16 LCD display, the instructions to the user can be stated very simply as: *= Back Up 0OK #=Fwd/Down/Send Of course a larger display can be used, including a graphical display.
When the program passes to one of the sub-programs 101-106, the user can navigate back to the main menu program by pressing the "*" (star) key on the keypad 14.
Similarly, each of the sub-programs 101-106 has its own subroutines.
Phone book sub-program 101 has the following subroutines (not shown): search, add entry, edit, status, speed dial and erase.
Messages subprogram 102 has the following subroutines: inbox 110, outbox 111, write messages 112 and message settings 113.
Call register sub-program 103 has the following subroutines (not shown): missed calls, received calls, dialled numbers, erase call lists, show durations.
Call divert subprogram 104 has the following sub-routines (not shown): divert all, divert when busy, divert no answer, divert when off, cancel all diverts.
Settings subprogram 105 has subroutines for terminal settings, phone settings, network settings, data settings, hand input/output settings. Each of these has further nested menu options, each with corresponding nested program code as follows:
A. Terminal settings 1 Display settings 1.1 Contrast 2 Security settings 2.1 SIM PIN 2.2 Terminal PIN 3 Service settings 3J Service PIN 3.2 Self Test 3.3 Firmware Update 3.4 RF Test 4 Restore Factory
B. Phone settings 1 My number sending 2 Dial delay
3 Alert settings 3.1 Ringing cadence 3.2 Incoming message 3.2.1 Ring 3.2.2 Message Waiting Light
C. Network settings 1 Network selection 1.1 Auto 1.2 Manual 2 Call waiting
D. Data settings
E. Input/Output settings 1 Channel 1 [In or Out] 1.1 Polarity 1.1.1 Off default 1.1.2 High 1.1.3 Low 1.2 Input or Output 1.2.1 Input (default) 1.2.2 Output 1.3 Text to send or receive 1.3.1 Edit [like SMS] 2 Channel 2 [Input only] 2.1 Polarity 2.1.1 Off (default) 2.1.2 High 2.1.3 Low 2.2 Threshold 2.2.1 [select from 0.5V to 4.5V using LCD contract method] 2.3 Text to send 2.3.1 Edit [like SMS]
Finally, clock sub-program 106 has alarm clock and clock setting subroutines (not shown).
All of the subprograms can be reached by navigating using the keys "0" for "OK" or "select", "*" for "back" or "up" and "#" for "forward" or "down".
When the UI program reaches a certain state or sub-program, the interpretations applied to the "*", "0" and "#" keys change from navigation commands for navigating between menu items to certain other functions now described.
For example, when the "write messages" subroutine 112 is entered (or a subprogram thereof), the "0" key is no longer interpreted as "OK" or "select" but instead is interpreted as "0" (zero) or, if depressed and held for a timeout period, it is interpreted as "space". The timeout period is measured by timer 44 in microcontroller 20.
Other letters can be entered in known ways using the keypad 14. For example, key "2" is used to enter "A", "B" or "C". There are several known ways to disambiguate between these options. For example, the key can be pressed repeatedly within a timeout period to cycle between the alternatives, or it can be held down to cycle between them. Language modelling software such as that supplied by Tegic (trade mark) can make the operation more efficient.
Thus, using just twelve keys on keypad 14, complex navigation between menu items can be achieved and alphanumeric text can be entered with spaces between words.
Punctuation marks and other symbols can be entered using the same keys in a similar manner. For such purposes, a line is preferably presented on the display 28 for displaying selectable symbol options. This is illustrated in Figure 3.
Figure 3 shows a display having a text area 200 and a symbol options line 201. A message being generated, part of which is shown on the lower line is "Please email me at
[email protected]". This text line includes alphabetic characters, spaces and the punctuation marks "." and "-" and the symbol "@". The alphabetical characters and spaces are created as already described. To generate punctuation marks, a punctuation mode is entered (e.g. by depressing and holding down "I". In this mode, punctuation marks appear in the symbol selection line 201. Using the "*" and "#" keys, a cursor 202 is moved left and right (or just using the "#" key it is cycled around to the right) until the desired symbol is indicated by the cursor, whereupon it is selected using the "0" key. Upon selection, the symbol appears in the text entry area 200 and the process is ready to generate the next symbol.
The symbol selection line 201 can be used not only for punctuation, but also for alphanumeric disambiguation or for language modelling (bigram, trigram and n- gram options).
There are other sub-programs in the UI where the interpretation of selected keys change when an operating mode is entered. E.g. in the "add entry" and "edit" modes of phone book sub-program 101, names and other alphanumeric text can be entered in the same manner as has been described for composing of messages.
Thus, a highly functional telephone capable of complex telephone and messaging functions has been described in which hand-held cellular telephone features can be operated and controlled using just twelve keys of a keypad of a standard DTMF telephone.
A second telephone line can be provided by connecting a fixed telephone line to the telephone apparatus 11. This provides a simple, flexible and low cost method of calling fixed line and cellular phones. By connecting the described FCT to a two-line telephone, one line being connected to the FCT and the other to a land line, a very flexible phone system is provided that allows a user to take a call from a land line and transfer it to a wireless network and vice versa. Alternatively, a second radiotelephone terminal device 10 can be provided to give a second telephone line.
A computer interface 30 is provided so that the device can be used as a high speed GPRS wireless modem. Although a RS232 serial interface only is described, serial-to-USB and serial-to-Bluetooth (trade mark) adapters can be added as optional accessories.
Since the device uses the cellular network to provide a total communications facility, it has the ability to remotely sense and control any type of equipment at the terminal's location. For this purpose, a further digital input/output channel (not shown) is provided and an analogue input/output (not shown) is provided connected by a simple 3.5mm stereo jack socket on the terminal.
By way of example, one of these inputs can be connected to receive an intruder alert from a suitable intruder sensor. Such an alert can cause an SMS text message to be sent immediately to any hand-held cellular telephone to alert someone nearby (or at a remote location) of the problem of an intruder. As another example, an SMS text message can be generated when the remote terminal's battery voltage drops below 11 volts and a similar warning message can be sent. Similarly, a specific SMS text sent to the terminal can activate either an opening or closing of a TTL switch so that most types of remote equipment may be activated.
Other modifications of detail can be made by one skilled in the art without departing from the scope of the invention as defined in the appended claims.