Led Indicators; Rf Interface - Multitech SocketModem GSM Hardware Manual

LED Indicators

The LEDs are used to indicate the working mode of the SocketModem. The LS LED indicates
Network Link Status and Network Strength
Network – defined by WMP100
Signal
Off
On
Slow Flash (on 200ms, off 2s)
Quick flash (on 200ms, off 600ms)
Very quick flash (on 100ms, off 200ms)
Signal Strength
Signal
Off
On
Quick flash (on 200ms, off 600ms)
Very quick flash (on 100ms, off 200ms)

RF Interface

Radio Characteristics
Frequency RX 869 to 894 MHz
Frequency TX 824 to 849 MHz
RF Power
Stand
Impedance
VSWR
Typical Radiated Gain
RF Performances
RF performances are compliant with the ETSI recommendation 05.05 and 11.10.
The main parameters are:
RF Connection
The RF connector on the SocketModem GSM is a UFL standard type. An antenna can be directly
connected through a mating UFL to SMA adapter.
Multi-Tech Systems, Inc. SocketModem GSM Hardware Guide for Developers
GSM 850 EGSM 900
925 to 960 MHz
880 to 915 MHz
2W at 12.5% duty 2W at 12.5% duty
cycle cycle
0 dBi on azimuth plane
Receiver Features
•
EGSM Sensitivity : < -104 dBm
•
GSM 1800/GSM 1900 Sensitivity : < -102 dBm
•
Selectivity @ 200 kHz : > +9 dBc
•
Selectivity @ 400 kHz : > +41 dBc
•
Dynamic range : 62 dB
•
Intermodulation : > -43 dBm
•
Co-channel rejection : + 9 dBc
Transmitter Features
•
Maximum output power (EGSM) : 33 dBm ± 2 dB
•
Maximum output power (DCS/PCS) : 30 dBm ± 2 dB
•
Minimum output power (EGSM): 5 dBm ± 5 dB
•
Minimum output power (DCS/PCS): 0 dBm ± 5 dB
•
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
•
Phase error at peak power : < 5 ° RMS
•
Frequency error : ± 0.1 ppm max
What Is Indicated
Processor Off
Processor On – Not registered on the network
Registered on network
Registered on the network – Communication in
progress
Bad software; software is bad or not compatible
What Is Indicated
Processor off or modem not registered on network
Good GSM signal (RSSI >= 12)
Weak GSM signal (7 <= RSSI < 12)
Very weak or no GSM signal (RSSI < 7)
GSM 1800
1805 to 1880 MHz 1930 to 1990 MHz
1710 to 1785 MHz 1850 to 1910 MHz
1W at 12.5% duty
cycle
50 ohms
<2
Chapter 1 – SocketModem GSM
GSM 1900
1W at 12.5% duty
cycle
10