초록 ▼

A dual-mode radiotelephone capable of operation in analog or digital modes. According to exemplary embodiments, a digital signal processor receives a speech signal to be transmitted in the digital or analog mode and generates In-phase (I) and Quadrature (Q) modulating signals. The I and Q signals ar

A dual-mode radiotelephone capable of operation in analog or digital modes. According to exemplary embodiments, a digital signal processor receives a speech signal to be transmitted in the digital or analog mode and generates In-phase (I) and Quadrature (Q) modulating signals. The I and Q signals are supplied to a quadrature modulator for generating a digitally modulated signal and are supplied to an analog modulator for generating an analog modulated signal.

대표청구항 ▼

A dual-mode radiotelephone capable of operation in analog or digital modes. According to exemplary embodiments, a digital signal processor receives a speech signal to be transmitted in the digital or analog mode and generates In-phase (I) and Quadrature (Q) modulating signals. The I and Q signals ar

A dual-mode radiotelephone capable of operation in analog or digital modes. According to exemplary embodiments, a digital signal processor receives a speech signal to be transmitted in the digital or analog mode and generates In-phase (I) and Quadrature (Q) modulating signals. The I and Q signals are supplied to a quadrature modulator for generating a digitally modulated signal and are supplied to an analog modulator for generating an analog modulated signal. tion; and in response to said allocation data, the third mobile station refraining from sending transmissions during said time period. 3. The method according to claim 2, in response to the second mobile station terminating the speech item, the method further comprises: allocating, in said allocation step, after the termination of said speech item of the second mobile station, a desired number of time slots or time periods from a time period of the frame structure that is of a desired length to said third mobile station participating in the group call for transmission of signalling messages; allocating, in said allocation step, a certain time period from said time period of a desired length only to the first mobile station for transmission of signalling messages; transmitting, in said transmission step, to the mobile stations participating in said group call a first notification to the effect that said time slots or time periods of said frame structure are allocated only to the mobile stations participating in said group call; transmitting, in said transmission step, to the first mobile station a second notification to the effect that said certain time period of said frame structure is allocated to the first mobile station, wherein in response to the first notification, the mobile stations that participate in said group call being able to send a signalling message during said time slots or time periods, and in response to the second notification, the first mobile station being able to send its transmission during said time period. 4. The method according to claim 3, wherein in response to the first notification, the mobile stations that participate in said group call store data indicating which time slots or time periods of said frame structure are allocated to the mobile station participating in said group call. 5. The method according to claim 3, wherein in response to the second notification, the first mobile station stores in memory data indicating which time period of said frame structure is allocated to the first mobile station. 6. The method according to claim 2, wherein the third mobile station, in response to said allocation data, stores information in memory to the effect that said time period of said frame structure is allocated to the first mobile station. 7. The method according to claim 2, further comprising: instructing the second mobile station to terminate the speech item in response to said signalling message sent by the first mobile station; sending a transmission prompt to the first mobile station; and sending first mobile station transmissions in time slots indicated by the transmission prompt. 8. The method according to claim 1, wherein said time periods are time slots of said frame structure, or parts of such time slots. 9. The method according to claim 1, further comprising: transmitting said allocation data or second notification to the first mobile station, wherein in response to said allocation data or second notification, the first mobile station being able to transmit a signalling message to said network infrastructure during said time period. 10. The method according to claim 1, wherein said signalling messages are speech item request signals. 11. The method according to claim 1, wherein said signalling messages are packet form data. 12. The method according to claim 11, further comprising: transmitting, by the first mobile station, part of the data to be transmitted in said signalling message, whereby part of the data to be transmitted does not fit into the first time period used; requesting the network infrastructure to allocate more time to the first mobile station in said frame structure for transmission of the remaining data from the first mobile station to the network infrastructure; allocating additional time from said frame structure to the first mobile station in the network infrastructure for transmission of the remaining data; and transmitting a notification of the allocated additional time to the first mobile station and the third mobile station. 13. The method according to claim 12, wherein a desired time period is allocated from said frame structure to the first mobile station for transmission of the remaining data. 14. The method according to claim 12, wherein one or more time slots are allocated from said frame structure to the first mobile station for transmission of the remaining data. 15. The method according to claim 1, wherein said signalling messages are status information messages. 16. The method according to claim 1, wherein said signalling message comprises position data indicating the location of the first mobile station. 17. A mobile communication system comprising first, second and third mobile stations, a mobile exchange for relaying group calls and transmissions and for maintaining a group call, said mobile stations that participate in said group call communicating in speech items, a base station for maintaining a frame structure comprising time slots that the second mobile station sending a speech item employs in a speech item, the mobile communication system comprising: allocation means for allocating time slots or a time period from the frame structure of said group call, so that only the first mobile station can send signalling messages in certain time slots or time periods to said mobile exchange; a first transmission means for sending the first mobile station and the third mobile station data in a control message indicating in which time slots or time periods only the first mobile station may transmit; and a first control means in said third mobile station for preventing transmission of signalling messages in said time slots or time periods allocated to said first mobile station. 18. The mobile communication system according to claim 17, wherein said frame structure comprises time periods that are common to the first mobile station and the third mobile station for transmission of signalling messages to said base station, wherein said allocation means are arranged to allocate a certain time period of said common time periods only to the first mobile station for transmission of signalling messages, and said transmission means are arranged to send the third mobile station a control message to the effect that said time period of said frame structure is allocated to the first mobile station. 19. The mobile communication system according to claim 17, further comprising: a second control means, responsive to said signalling message sent by the first mobile station, for instructing the second mobile station to terminate the speech item; and a second transmission means, responsive to said signalling message sent by the first mobile station, for sending a transmission prompt to the first mobile station. 20. A mobile station of a mobile communication system communicating in a group call, the mobile station comprising: a transceiver for sending transmissions in a frame structure comprising time slots that a second mobile station sending a speech item in a group call employs in a speech item, and time periods that are common to the mobile stations that are not sending a speech item, for transmitting signalling messages to a network infrastructure; a first control unit; a user interface; a memory unit; and a second control unit, responsive to a control message sent by said mobile communication system, for preventing transmission of signalling messages in the time slots or time periods allocated to a first mobile station as indicated in said control message. 21. The mobile station according to claim 20, wherein in response to said control message, said memory unit is arranged to store information to the effect that said time period of said frame structure is allocated to some other mobile station. 22. A mobile station of a mobile communication system, communicating in a group call, the mobile station comprising: a transceiver for sending tr ansmissions in a frame structure comprising time slots that a second mobile station sending a speech item in a group call employs in a speech item, and time periods that are common to the mobile stations that are not sending a speech item, for transmitting signalling messages to the network infrastructure; a control unit; a user interface; a memory unit, wherein in response to a control message sent by said mobile communication system, the transceiver of the mobile station is arranged to send a signalling message during the time period of the frame structure of said group call indicated in the control message. 23. The mobile station according to claim 22, wherein in response to a transmission prompt sent by said mobile communication system, said transceiver is arranged to start sending transmissions in time slots indicated in said transmission prompt.