MULTIPLE FORMAT SIGNALLING PROTOCOL FOR A SELECTIVE CALL RECEIVER

Abstract: A selective call receiver (11) comprises a receiver (13) for receiving a signal, the signal comprising an address identifying the selective call receiver, a first information packet having a first information format, a second information packet having a second information format, and a control character. An output device (17) presents the first information packet in a first output mode corresponding to the first information format in response to the control character, and the second information packet in a second output mode corresponding to the second information format in response to the address or a second control character.

Description: MULTIPLE FORMAT SIGNALLING PROTOCOL FOR A SELECTIVE CALL RECEIVER Field of the Invention This invention relates in general to selective call receivers and more specifically to a selective call receiver signalling format having a single address and accommodating two or more information formats including, for example, numeric, alphanumeric, graphic, and voice. Background of the Invention Several protocols have been designed for transferring messages to selective call receivers. These protocols include POCSAG (Great Britain's Post Office Code Standardization Advisory Group) and GSC (Golay Sequential Code). A message comprises an address if the message is a tone only message, or an address and information if the message is a data message. The information in a data message conventionally comprised one of several information formats including numeric (transmitted by BCD), alphanumeric (transmitted by ASCII), or voice (transmitted by digital or analog). A preamble of a POCSAG signal comprises a number of zero-to-one transitions for bit syn-chrortization. The first word following the preamble is a sync code word which contains a predetermined binary sequence used for frame synchronization. Sixteen words of information, each comprising a selective call address and an associated message, follow before the sync code is repeated. The structure of the addresses and information may be referred to as the signalling format. In a GSC selective call network, the receivers are divided into a plurality of groups and a twenty three bit code in the preamble selects one of the groups in addition to providing means for bit and frame synchronization. Following the preamble, a start code indicates that the preamble is finished and the information following contains selective call addresses of selective call receivers within the group and messages for those selective call receivers in a pattern of sixteen information words followed by one start code word. However, in both POCSAG and GSC, as in other known protocols, the information following each of the addresses comprised only one information format. Each address would specify to the selective call receiver receiving that address whether its information following would be numeric, alphanumeric, or voice. The selective call receiver would thereby encode the proper format as transmitted, e.g., BCD or ASCII. Thus, what is needed is a selective call receiver signalling format having a single address and accommodating two or more information formats. Summary of the Invention Accordingly, it is an object of the present invention to provide a selective call receiver signalling format having a single address and accommodating two or more data types. In carrying out the above and other objects of the invention in one form, there is provided a selective call receiver comprising a receiver for receiving a signal; the signal comprising an address identifying the selective call receiver, a first information packet having a .first information format, a second information packet having a second information format, and a control character; and an output device for presenting the first information packet in a first output mode corresponding to the .first information format in response to the control character, and the second information packet in a second output mode corresponding to the second information format. Brief Description of the Drawings FIGURE 1 is a block diagram of a conventional selective call receiver. FIGURE 2 is a diagram of the signalling format in accordance with a first embodiment. FIGURE 3 is a diagram of the signalling format in accordance with a second embodiment. FIGURE 4 is a diagram of the signalling format in accordance with a third embodiment. Detailed Description of the Invention Referring to FIGURE. 1, a transmitter 10 sends signals to an electronic device 11 such as a selective call receiver including a pager comprises an antenna 12 for receiving the signals coupled to a receiver circuit 13 which demodulates the sigrteds received. A memory 15 is coupled to the microprocessor 14 for storing those messages containing the address of the selective call receiver 11 as determined by the microprocessor 14. The portion of the memory 15 in which the address or address are stored is generally referred to as the code plug. The microprocessor 14 also controls the storing and recalling of those messages. An alert device 16 provides an alert, i.e., audible, visual or tactile, to the user that a message has been received and is ready to be presented. An output device 17 may be a visual display for presenting the message in a numeric mode, a graphic mode or an alphanumeric mode, for example, and/or a speaker controlled by the microprocessor 14 for presenting the message in an audible mode. The controls 18 allow the user to command the microprocessor 14 to perform the selective call receiver 11 operations well known to those skilled in the art and typically include control switches such as an on/off control button, a function control, etc. For a more detailed description of the structure and operation of a selective call radio paging receiver of the type shown in FIG. 1, reference is made to U.S. Patent Number 4,518,961, U.S. Patent Number 4,649,538, and U.S. Patent Number 4,755,816, all commonly assigned to the assignee of the present invention, and the teachings of which are hereby incorporated by reference. Referring to FIGURE 2, the signalling format in accordance with a first embodiment of the present invention is structured so it can coexist with present selective call protocols such as GSC (Motorola's Golay Sequential Code) or POCSAG (Great Britain's Post Office Code Standardization Advisory Group) on a single or multiple frequency channels. The signaUing format comprises a preamble, a code word, an address Ai, messages MIA M2 V and M3N and control characters CCi and CC 2 . The preamble and code word for example, in POCSAG, provides bit and frame synchronization, respectively. In GSC, the preamble provides both bit and frame synchronization and the code word generally is a start code for the subsequent information. The address Ai identifies the desired selective call receiver or receivers in a manner well known to those skilled in the art. The address Ai informs the selective call receiver that the following message MIA is transmitted in .ASCII and will be alphanumeric. The control character CCi informs the selective call receiver that the message M2V immediately following is transmitted in digital or analog and will be presented aurally (voice). The control character CC2 informs the selective call receiver that the message M3N immediately following is transmitted in BCD and will be numeric. The control character CC3 informs the selective call receiver that the message M4N immediately folowing is transmitted in pixal or a data stream corrosponding to FAX 1, FAX 2, FAX 3, or FAX 4 protocols, for example, and will be presented graphically. Referring to FIGURE 3, a second embodiment of the signaUing format comprises an address Ai, messages MIA, M2V and M3N and control characters CCi, CC2 and CC3. In ttύs embodiment, the address does not specify a format; however, the control characters CCi, CC2 and CC3 precede each of the words of messages MIA, M2V and respectively, thereby informing the selective call receiver in which the following message or messages wiU be received and presented. the POCSAG format having a 21 bit word and 10 bit parity in the known 31/21 bit format, the control characters CCi, CC2 and CC3 may each comprise the first three bits of the 21 bit words with the 10 bits for parity immediately following the 21 bit word. For example, the control character CCi may comprise the bits "000", the control character CC2 may comprise the bits "001", and the control character CC2 may comprise the bits "010". Since the control signal is transmitted with each word, this embodiment provides immunity to control signals being corrupted by noise. Other information formats, i.e., graphics, may be transmitted in a s.imilar manner. Referring to FIGURE 4, a third embodiment of the signalling format comprises an address Ai, messages MIA, M2V and M3 control characters CCi, CC2, CC3 and CQ, and message length designators LDi, LD2, and LD3. Each of the message length designators LDi, LD2, and LD3 define the length of the respective messages MIA, M-2V and M3N. The control character CQ indicates that it is the last control character and the messages follow immediately thereafter. Other information formats, i.e., graphics, may be transmitted in a similar manner. It should be apparent in each of the three embodiments illustrated, that each of the messages MIA M2V and M3N may alternative comprise several messages in each information format, respectively, and may be interchanged in order. Furthermore, any number of information formats may be transmitted with a single address wherein the information is transmitted in an efficient format, i.e., a number character may be transmitted using only four bits in a BCD format, an alpha character may be transmitted using only seven bits in an ASCII format, and graphic information may be transmitted in a pixal format or one of the FAX formats. Trans.mitting each information type in an optimum format provides for efficient usage of a paging channel. For example, transmitting a number or an alpha character in a graphic format would require at least 35 pixel bits and transmitting numbers in an ASCII format would require seven bits.

Claims: CLAIMS 1. A selective call receiver comprising: receiver means for receiving a signal, the signal comprising: an address identifying the selective call receiver; an information packet comprising an information format; and a control character; and presentation means for presenting the information packet in an output mode corresponding to the information format in response to the control character. 2. The selective call receiver according to claim 1 wherein the output mode comprises a numeric display. 3. The selective call receiver according to claim 1 wherein the output mode comprises .an alphanumeric display. 4. The selective call receiver according to claim 1 wherein the output mode comprises an audible output. 5. The selective call receiver according to claim 1 wherein the output mode comprises a graphics output. 6. A selective call receiver comprising: receiver means for receiving a signal, the signal comprising: an address identifying the selective call receiver; a first information packet comprising a first information format; a second information packet comprising a second information format; and a first control character; and presentation means for presenting the first information packet in a first output mode corresponding to the first information format in response to the first control character, and the second information packet in a second output mode corresponding to the second information format. 7. The selective caU receiver according to claim 6 wherein the second information packet is presented in response to the address. 8. The selective call receiver according to claim 6 wherein the signal further comprises a second control signal, the second information packet being presented in response thereto. 9. The selective call receiver according to chrim 6 wherein one of the first and .second output modes comprises a numeric display. 10. The selective call receiver according to daim 9 wherein the other of the first and second output modes comprises an alphanumeric display. 11. The selective call receiver according to clam 9 wherein the other of the first and second output modes comprises an audible output. 12. The selective call receiver according to daim 6 wherein one of the first and second output modes comprises an alphanumeric display. 13. The sdective caU receiver according to daim 12 wherein the other of the first and second output modes comprises an audible output. 14. The sdective call receiver according to daim 6 wherein the output mode comprises a graphics display. 15. A selective caH receiver system comprising: transmitter means for transmitting a signal; receiver means for receiving the signal, the signal comp.rising: an address identifying the selective call receiver; a .first .information packet comprising a first information format; and a first control character; and presentation means for presenting the first information packet in a first output mode corresponding to the first information format in response to the first control character. 16. The sdective call receiver according to claim 15 wherein the first output mode comprises a numeric display. 17. The selective call receiver according to claim 15 wherein the first output mode comprises an alphanumeric display. 18. The sdective call receiver according to claim 15 wherein the first output mode comprises an audible output. 19. The sdective call receiver according to claim 15 wherein the output mode comprises a graphics display. 20. The sdective call receiver system according to claim 15 wherein the signal further comprises a second information packet comprising a second information format, the presentation means presenting the second information packet in a second output mode corresponding to the second information format. 21. The selective call receiver according to claim 20 wherein the second information packet is presented in response to the address. 22. The selective call receiver according to claim 20 wherein the signal further comprises a second control signal, the second information packet being presented in response thereto. 23. The selective call receiver according to claim 20 wherein one of the first and second output modes comprises a numeric display. 24. The selective call receiver according to daim 23 wherein the other of the first and second output modes comprises an alphanumeric display. 25. The selective call receiver according to daim 23 wherein the other of the first and second output modes comprises an audible output. 26. The selective call receiver according to claim 20 wherein one of the first and second output modes comprises an alphanumeric display. 27. The selective call receiver according to daim 26 wherein the other of the first and second output modes comprises an audible output. 28. The selective call receiver according to claim 20 wherein the output mode comprises a graphics output.

Inventors: DELUCA JOAN SABIN, DELUCA MICHAEL JOSEPH, DELUCA, JOAN, SABIN, DELUCA, MICHAEL, JOSEPH
Applicants: MOTOROLA INC, MOTOROLA, INC.
Application year: 1991
Main classification: H04Q7
IPC codes: H04W88