The LTE cellular module in the OnCell devices supports 1T2R, which means antenna A (ANT A) port supports both 1T and 1R and antenna B (ANT B) port only supports 1R. Therefore, when you initially try to establish a connection with only the ANT B port, the devices will not connect to the cellular network. But, if you try to connect with ANT A port, you will be able to establish a connection.
However, after a connection is established, the devices remain connected to the cellular network even if you remove one of the antennas because:
- The antenna’s SMA connector continues to transmit signals.
- After a connection is established, the antenna does not need high power to remain connected.
A series of use cases and the corresponding behavior of the antenna ports is given in the following table:
|
No.
|
Action
|
ANT A
|
ANT B
|
Result
|
|
1
|
Cold Start
|
No
|
Yes
|
No connection
|
|
2
|
After 10 min.
|
No
|
Yes
|
No connection
|
|
3
|
After 5 min, remove ANT B and connect ANT A
|
Yes
|
No
|
Connected to ISP’s cellular network
|
|
4
|
Remove ANT A
|
No
|
No
|
Remains connected to the cellular network (relies on the RSSI)
|
|
5
|
After 10 min.
|
No
|
No
|
Remains connected to the cellular network (relies on the RSSI)
|
|
6
|
Connect ANT B
|
No
|
Yes
|
Remains connected to the cellular network (relies on the RSSI)
|