SARA-G450 - System integration manual
UBX-18046432 - R08 System description Page 46 of 143
C1-Public
1.13 System features
1.13.1 Network indication
The GPIO1, GPIO2, GPIO3 or GPIO4 can be configured alternatively from their default settings to
indicate network status (i.e. no service, registered home network, registered visitor network, voice call
or data transmission enabled), by means of the AT+UGPIOC command.
For the detailed description, see section 1.11 and the u-blox AT commands manual [11], GPIO
commands.
1.13.2 Antenna detection
The ANT_DET pin of SARA-G450 modules is an Analog to Digital Converter (ADC) provided to sense
the presence of an external antenna when optionally set by the +UANTR AT command.
The external antenna assembly must be provided with a built-in resistor (diagnostic circuit) to be
detected, and an antenna detection circuit must be implemented on the application board to properly
connect the antenna detection input (ANT_DET) to the antenna RF interface (ANT).
For more details regarding feature description and detection / diagnostic circuit design-in, see
sections 1.7.2 and 2.4.2 and the u-blox AT commands manual [11].
1.13.3 Jamming detection
☞ Not supported by the “00” product version.
In real network situations, modules can experience various kind of out-of-coverage conditions: limited
service conditions when roaming to networks not supporting the specific SIM, limited service in cells
which are not suitable or barred due to operators’ choices, no cell condition when moving to poorly
served or highly interfered areas. In the latter case, interference can be artificially injected in the
environment by a noise generator covering a given spectrum, thus obscuring the operator’s carriers
entitled to give access to the cellular service.
The jamming detection feature detects such “artificial” interference and reports the start and stop of
such conditions to the client, which can react appropriately by e.g. switching off the radio transceiver
to reduce power consumption and monitoring the environment at constant periods.
The feature detects, at the radio resource level, an anomalous source of interference and signals it to
the client with an unsolicited indication when the detection is entered or released. The jamming
condition occurs when:
The module has lost synchronization with the serving cell and cannot select any other cell
The band scan reveals at least n carriers with power level equal or higher than the threshold
On all such carriers, no synchronization is possible
The jamming condition is cleared when any of the above mentioned statements does not hold.
The congestion (i.e. jamming) detection feature can be enabled and configured by the +UCD AT
command (for more details, see the u-blox AT commands manual [11]).