Cellular telephone signalling circuit operable with different cellular telephone systems
First Claim
1. A baseband signalling circuit for use with a cellular telephone that comprises a cellular telephone control means for selectively setting a state of a control signal line as a function of a received cellular communications system signalling protocol, said baseband signalling circuit being responsive to a first state of said control signal line for operating in accordance with a first cellular communications system signalling protocol that employs a signalling frequency that is greater than one kilo-Hertz, said baseband signalling circuit further being responsive to a second state of said control signal line for operating in accordance with a second cellular communications system signalling protocol that employs a signalling frequency that is less than one kilo-Hertz, said baseband signalling circuit further comprising means for recovering data bits from a received signal, said recovering means being responsive to the first state of said control signal line for sampling the received signal at a first sampling rate, said recovering means being responsive to the second state of said control signal line for sampling the received signal at a second sampling rate, wherein said first sampling rate is at least an order of magnitude greater than said second sampling rate.
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Accused Products
Abstract
Apparatus operable with different cellular telephone systems and signalling protocols is described. Signalling messages, both data messages and supervisory related signals between a cellular telephone microcontroller (4) and a base station are transferred via a baseband signalling circuit (10). The baseband signalling circuit is operable to employ different signalling protocols, the protocol being selected by control bits provided from the microcontroller to the signalling circuit. In a preferred embodiment, the signalling protocol selection is made between an AMPS/TACS signalling protocol and a NAMPS/NTACS subaudible signalling protocol.
103 Citations
18 Claims
- 1. A baseband signalling circuit for use with a cellular telephone that comprises a cellular telephone control means for selectively setting a state of a control signal line as a function of a received cellular communications system signalling protocol, said baseband signalling circuit being responsive to a first state of said control signal line for operating in accordance with a first cellular communications system signalling protocol that employs a signalling frequency that is greater than one kilo-Hertz, said baseband signalling circuit further being responsive to a second state of said control signal line for operating in accordance with a second cellular communications system signalling protocol that employs a signalling frequency that is less than one kilo-Hertz, said baseband signalling circuit further comprising means for recovering data bits from a received signal, said recovering means being responsive to the first state of said control signal line for sampling the received signal at a first sampling rate, said recovering means being responsive to the second state of said control signal line for sampling the received signal at a second sampling rate, wherein said first sampling rate is at least an order of magnitude greater than said second sampling rate.
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4. A baseband signalling circuit for use with a cellular telephone that comprises a cellular telephone control means for selectively setting a state of a control signal line as a function of a received cellular communications system signalling protocol, said baseband signalling circuit being responsive to a first state of said control signal line for operating in accordance with a first cellular communications system signalling protocol that employs a continuous signalling frequency that is greater than one kilo-Hertz, said baseband signalling circuit further being responsive to a second state of said control signal line for operating in accordance with a second cellular communications system signalling protocol that employs a signalling frequency that is less than one kilo-Hertz, wherein the first cellular communications system signalling protocol is selected from Advance Mobile Phone Services (AMPS) and Total Access Communication System (TACS) signalling protocols, and wherein the second cellular communications system signalling protocol is selected from narrowband Advanced Mobile Phone Services (NAMPS) and Narrowband Total Access Communication System (NTACS) signalling protocols;
- said baseband signalling circuit further including decoder means, responsive to the first state of said control signal line, for operating as a Manchester decoder for decoding received AMPS/TACS data that is input into said baseband signalling circuit, said decoder means being responsive to the second state of said control signal line for operating as a one bit integrator for decoding received NAMPS/NTACS data that is input into said baseband signalling circuit.
- View Dependent Claims (5, 6, 8)
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9. A baseband signalling circuit for use with a cellular telephone, said baseband signalling circuit including first means for interfacing to a cellular telephone control means and second means for interfacing to a radio frequency reception and transmission means, said baseband signalling circuit being responsive to a first state of a control signal line for operating in accordance with Advanced Mobile Phone Services (AMPS)/Total Access Communication System (TACS) signalling protocols, said baseband signalling circuit further being responsive to a second state of said control signal line for operating in accordance with Narrowband Advanced Mobile Phone Services (NAMPS)/Narrowband Total Access Communication System (NTACS) subaudible signalling protocols, wherein the state of the control signal line is selectively controlled by said cellular telephone control means as a function of a received cellular communications system signalling protocol, wherein said first interface means includes a multi-bit data bus and an interrupt signal line that is coupled between said baseband signalling circuit and said cellular telephone control means, and wherein said baseband signalling circuit is responsive to information written over said data bus by said cellular telephone control means for selectively generating said interrupt signal on an occurrence of a reception of eight data bits from said second interface means or on an occurrence of a reception of one bit from said second interface means.
- 10. A baseband signalling circuit for use with a cellular telephone, said baseband signalling circuit including first means for interfacing to a cellular telephone control means and second means for interfacing to a radio frequency reception and transmission means, said baseband signalling circuit being responsive to a first state of a control signal line for operating in accordance with Advanced Mobile Phone Services (AMPS)/Total Access Communication System (TACS) signalling protocols, said baseband signalling circuit further being responsive to a second state of said control signal line for operating in accordance with Narrowband Advanced Mobile Phone Services (NAMPS)/Narrowband Total Access Communication System (NTACS) subaudible signalling protocols, wherein the state of the control signal line is selectively controlled by said cellular telephone control means as a function of a received cellular communications system signalling protocol, said baseband signalling circuit further comprising decoder means, responsive to the first state of said control signal line, for operating as a Manchester decoder for decoding AMPS/TACS data that is received from said radio frequency receiving means, said decoder means being responsive to the second state of said control signal line for operating as a one bit integrator for decoding NAMPS/NTACS Digital Supervisory Audio Tone (DSAT), Word Synchronization (WSYNC), and DATA WORD information that is received from said radio frequency receiving means.
- 13. A baseband signalling circuit for use with a cellular telephone, said baseband signalling circuit including first means for interfacing to a cellular telephone control means and second means for interfacing to a radio frequency reception and transmission means, said baseband signalling circuit being responsive to a first state of a control signal line for operating in accordance with Advanced Mobile Phone Services (AMPS)/Total Access Communication System (TACS) signalling protocols, said baseband signalling circuit further being responsive to a second state of said control signal line for operating in accordance with Narrowband Advanced Mobile Phone Services (NAMPS)/Narrowband Total Access Communication System (NTACS) subaudible signalling protocols, wherein the state of the control signal line is selectively controlled by said cellular telephone control means as a function of a received cellular communications system signalling protocol, and wherein said baseband signalling circuit is further comprised of means for recovering data bits from a signal received from said second interface means, said recovering means being responsive to the first state of said control signal line for sampling the received signal at a first sampling rate, said recovering means being responsive to the second state of said control signal line for sampling the received signal at a second sampling rate, wherein said first sampling rate is at least an order of magnitude greater than said second sampling rate.
Specification