Murata 1SC / Quectel BG770A-SN Setup Guide

This guide walks through the setup and configuration process for using the Murata 1SC or Quectel BG770A-SN module with a Soracom planNT1 SIM card for NTN satellite communication via the Skylo network.

This guide is not suitable for the setup of the Soracom iSIM Evaluation Kit (EVK) based on Murata Type 1SC, which is a cellular evaluation kit without satellite connectivity.

Requirements

Murata 1SC or Quectel BG770A-SN-based evaluation kit (EVK) or module
Soracom IoT SIM provisioned with planNT1 and the correct IMSI enabled. This process is described in our Air for Satellite Configuration documentation.
Serial terminal software (e.g., TeraTerm, PuTTY, minicom)
USB cable for EVK connection
Internet-connected PC

Hardware Setup

Insert your planNT1 provisioned SIM card into the device.
Connect the EVK to your PC using the USB cable.
Determine the serial port assigned to the EVK:
- Windows:
  1. Open Device Manager by pressing Win+X then selecting Device Manager.
  2. Expand Ports (COM & LPT) and note the COM port number assigned to your device (COM3). If multiple devices are connected, the easiest way to identify the correct port is to open Device Manager first, then plug in your EVK and watch for the newly listed entry.
- Linux:
  1. Run dmesg | grep tty after plugging in the device to see which /dev/ttyUSB* or /dev/ttyACM* port the EVK is assigned.
  2. Alternatively, use ls /dev/tty* before and after plugging in to spot the new device.
Launch a serial terminal and connect to the EVK's COM port:

In this guide PuTTY and minicom are used to create a serial connection with a Windows or Linux PC respectively, other serial terminals can be used as well
- Windows (PuTTY):
  1. Download and install PuTTY from https://www.putty.org/.
  2. Select Serial as the connection type.
  3. Enter the COM port number and set the speed (baud rate) as specified by your EVK (typically 115200).
  4. Click Open to start the session.
- Linux (bash):
  1. Install minicom with sudo apt install minicom or your distribution's package manager.
  2. Use minicom to connect to the correct tty port at 115200 baud:sudo minicom -D /dev/ttyUSB0 -b 115200.

Initial Configuration

After opening a terminal connection, configure the module with the following AT commands:

Set the module to offline mode:
```
AT+CFUN=0
```
Set the APN for Soracom connectivity:
```
AT%PDNSET=1,"soracom.io","IP"
```
Select the RAT image for NB-IoT NTN operation:
```
AT%RATIMGSEL=2
```
Activate NB-IoT in NTN mode:
```
AT%RATACT="NBNTN",1
```
Set the frequency band for your region: Use Band 256 for Europe, Band 255 for UK/Oceania, or Band 23 for US/Canada.
```
AT%SETCFG="BAND","256"
```
Set the estimated GPS location (latitude, longitude, altitude in meters):
```
AT%NTNCFG="pos","stat","51.5396","-0.1597","20"
```
(Optional) Configure the use of internal GNSS:
1. Enable use of internal GNSS:
```
AT%SETACFG="ntn.conf.gnss_in_use","ignss"
```
2. Enable the local GNSS service:
```
AT%SETACFG="locsrv.operation.locsrv_enable","true"
```
3. Activate internal GNSS:
```
AT%IGNSSACT=1
```
Enable the modem to connect to the Skylo network:
```
AT+CFUN=1
```
Enable unsolicited result codes for network registration:
```
AT+CEREG=2
```
Ping the Soracom ping server:
```
AT%PINGCMD=0,"100.127.100.127",1,50,30
```
Sending pings via satellite is not as reliable as general cellular connectivity due to the high latency. Packets may be lost either during transmission or reception. Expect that pings may fail.

Test Data Uplink Sequence

Follow these steps to test UDP data uplink using AT commands.

Add your planNT1-provisioned IoT SIM, to a group configured to use Unified Endpoint and [Soracom Harvest]
Allocate a UDP socket:
```
AT%SOCKETCMD="ALLOCATE",1,"UDP","OPEN","100.127.69.42",23080,0 
```
The IP address of Soracom Unified Endpoint is subject to change. If the IP address above does not work, query the DNS for unified.soracom.io using a device connected to the Soracom network.

The URL unified.soracom.io may also be used directly in the AT%SOCKETCMD, but may fail resolution due to the long latency times that can be expected with satellite communications.
Activate the socket:
```
AT%SOCKETCMD="ACTIVATE",1
```

Send Hello, world! as hex:

AT%SOCKETDATA="SEND",1,13,"48656C6C6F2C20776F726C6421"

Check the response:
1. If data is received successfully the module will return the following reply to indicate arriving data:
```
%SOCKETEV:1,1
```
2. Read the arriving data:
```
AT%SOCKETDATA="RECEIVE",1,50
```
3. Expected response:
```
%SOCKETDATA:1,3,0,"323031","100.127.69.42",23080
```
  This corresponds to ASCII 201, meaning success.
Close the socket:
```
AT%SOCKETCMD="DELETE",1
```

Power Saving Modes

Both Power Saving Mode (PSM) and extended Discontinuous Reception (eDRX) are available for power optimization. The configuration commands are identical across all supported module types.

eDRX Configuration

eDRX allows the device to sleep for extended periods while remaining registered to the network.

Parameters:

eDRX cycle length: 10.24 seconds - 2.9127 hours [0001 - 1111]bin
Paging Time Window: 10.24 seconds (fixed) [0011]bin
Paging sequence: 1 paging event every 30 seconds (packets discarded after >90 seconds)

Example: Configure eDRX with a 20.48 second cycle:

AT+CEDRXS=2,5,"0010"

PSM Configuration

PSM provides deeper power savings by allowing the device to enter a sleep state where it's unreachable by the network.

Timing Parameters:

RRC Connection Release (transition to idle): 80 seconds
PSM Active Timer (T3324): 0 seconds - 3.1 hours [00000000 - 01011111]bin
(Setting to 0 bypasses idle mode and transitions directly to PSM)
Extended TAU Timer (T3412): Maximum 24 hours [maximum value: 00111000]

Example: Configure PSM with T3412 (periodic TAU) = 12 hours and T3324 (active timer) = 2 minutes:

AT+CPSMS=1,,,00101100,00100010

For assistance with AT+CPSMS command generation, use Soracom's online PSM calculation tool.

Troubleshooting

General troubleshooting steps for Air for Satellite connections can be found in our satellite troubleshooting documentation.

Debugging Notifications

The following optional commands can be used to enable notifications for debugging purposes:

Command	Description
`AT%NOTIFYEV="SIB31",1`	Enable notifications when satellite system information (SIB31) is received.
`AT%NTNEV="TA",1`	Enable TA (Timing Advance) debug event logging.
`AT%NOTIFYEV="RRCSTATE",1`	Enable RRC state change notifications (e.g., connected, idle).
`AT+CEREG=2`	Enable URC for network registration status.
`AT%IGNSSEV="FIX",1`	Enable notifications when a GPS fix is acquired.

Response Codes

You can monitor for the following response codes during the connection process to confirm network connection:

Response Code	Meaning
`%NOTIFYEV: "SIB31"`	Satellite detected
`%NOTIFYEV:"RRCSTATE",1`	RRC connected state
`+CEREG: 5,"0FBA",...`	Registered (roaming)