Figure 2.8 Gsm Communication Module - Thales Z-Max Operation And Application Manual

Motorola G18 GSM modem
GSM (Global System for Mobile communications) is a widely used cellular system
that can be used to carry either voice or data communications. The GSM modems
used in the Z-Max RTK system are housed in the Communication Module, Figure
2.8. Dialing of the modem can be controlled by the Front Panel User Interface of
the Z-Max or through application software running on a handheld computer. GSM
modems require the use of a SIM card. The SIM card helps maintain the security
of a GSM user account and is inserted into the modem through an access door
on the underside of the GSM enabled Communication Module. The GSM-enabled
communication module includes an integrated antenna which protrudes from the
top of the device.

Figure 2.8 GSM Communication Module

Data Link Configurations
While the cellular modems in the Communication Module serve as both the
transmitter and the receiver (transceiver), the radios in the Communication
Module are receivers only. The base receiver must have an external radio
168 Z-Max Surveying System Operation and Applications Manual