CellScan BG95M3

We are using Cellscan for cellular location

  1. how can we get TA information for LTE ?
  2. please provide more information on the cellscan algorithm. E.g if the scan is stopped after timeout , does the next scan start with the last band /channel ? Is the search depending on the serving cell information ?
  1. AT+QNWCFG=“TA” command can get TA, please take a reference with QNWCFG Application Note.

LTE EARFCN scan includes system scan and band scan. When the module shuts down, it will store the
current network registration information (e.g., EARFCN, PCI and so on). When the module powers on
next time for network registration, UE will try to acquire the stored network registration information. This
procedure is called system scan. This procedure will speed up the network registration process. If the
network information acquisition failed in system scan, UE will attempt to scan all supported bands, which
process constitutes the band scan.
According to statistics, the scan for all bands under eMTC and EGPRS takes about tens of seconds.
However, EARFCN scan will take longer under NB-IoT, due to the characteristics of NB-IoT network
(especially the weak signal feature). The following table shows the test results of some of the NB-IoT
bands, which displays the EARFCN scan time required in each band.


Thanks for the info !!

  • IF the modem is mobile and the modem shut down and reactivated in an area where the frequencies are different ( same operator , same band , but different EARFCN), does this mean that the modem will start a fresh scan according to the nwscanmode and nwscanseq ?
  • Please send the table with scan times in NBIoT
    Thanks !!



In normal cases, if the EARFCN in the current area is not detected during the last network stop, the System scan cannot detect this EARFCN during the current network start. Therefore, band scan is initiated to scan all supported bands. Even if the two EARFCN belong to the same band.