Ericsson M3090, Руководство интегратора

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Introduction 11
M3090 Integrator’s Manual, Doc.no: 198 17 - KRD 102 303 Uen, Rev B
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Power is supplied through the system connector. The required voltage is 6-9 V
DC (nominally 7.5 V).
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When the radio modem is powered, it operates in one of the following three
modes:
• sleep
• receiving
• transmitting
Unless communication within the Mobitex network is very intense, the radio
modem spends most of its time in the sleep mode. In this mode, the modem
waits for host requests and the air interface is inactive. The sleep mode is
entered whenever the radio modem is reset or powered on.
The radio modem enters receiving mode when:
• the power saving protocol says it is time to monitor the radio link (power
saving mode)
• the host requests that the radio link be constantly monitored (express mode)
• data from the network is expected
• the host requests access to the network
When data needs to be transmitted, the radio modem enters transmitting mode.
The time spent in this mode is minimized in order to reduce power
consumption.
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The host equipment must provide an external antenna. The antenna is connected
to the radio modem's antenna connector of the SMT type (from M/A Com, see
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).