Chapter 4 – Non-Electrical Interfaces
Multi-Tech Systems, Inc. MMCModem GPRS Developer’s Guide (S000445D)
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RF Interface
The impedance is 50 Ohms nominal.
RF Connector
The RF connector is MMCX standard type. An antenna can be directly connected through the
mating connector or using a small adapter.
RF Performances
RF performance is compliant with the ETSI recommendation ETSI TS 151 010-1.
Receiver Parameters:
•
GSM850 Reference Sensitivity = -104 dBm Static & TUHigh
•
EGSM900 Reference Sensitivity = -104 dBm Static & TUHigh
•
DCS1800 Reference Sensitivity = -102 dBm Static & TUHigh
•
PCS1900 Reference Sensitivity = -102 dBm Static & TUHigh
•
Selectivity @ 200 kHz: > +9 dBc
•
Selectivity @ 400 kHz: > +41 dBc
•
Linear dynamic range: 63 dB
•
Intermodulation: > -43 dBm
•
Co-channel rejection: > = 9 dBc
Transmitter:
•
Maximum output power (EGSM & GSM850): 33 dBm +/- 2 dB at ambient temperature
•
Maximum output power (GSM1800 & PCS1900): 30 dBm +/- 2 dB at ambient temperature
•
Minimum output power (EGSM & GSM850): 5 dBm +/- 5 dB at ambient temperature
•
Minimum output power (GSM1800 & PCS1900): 0 dBm +/- 5 dB at ambient temperature
•
H2 level : < -30 dBm
•
H3 level : < -30 dBm
•
Noise in 925 - 935 MHz : < -67 dBm
•
Noise in 935 - 960 MHz : < -79 dBm
•
Noise in 1805 - 1880 MHz : < -71 dBm
DTE/DCE Interface Rates
The table below indicates the anticipated modem-to-computer interface rates for both the 7.2 bits-
per-sample rate and the 8 bits-per-sample rate.
Projected DTE/DCE Interface Rates for 7.2/8K Hz Sample Rates
Bits per Sample
Projected DTE/DCE I/F
Rate @ 7.2K Hz
Projected DTE/DCE I/F
Rate @ 8K Hz Sample Rate
0.50 4800
9600
1 9600
19200
2 19200
19200
3 38400
38400
4 38400
57600
5 57600
57600
6 57600
115200
7 115200 115200
8 115200 115200
9 115200 115200
10 115200
115200
11 115200
115200
12 115200
Fast
13 Fast
Fast
