[Features]
The RS-MS3A is an Android device application designed to expand the DV mode capability of a D-STAR transceiver using a Terminal or an Access Point mode.
These modes enable D-STAR operations by sending signals from the D-STAR transceiver over the Internet even when that transceiver is out of range of a D-STAR repeater. The transceiver sends your voice signals using an Internet LTE or 5G network through an Android device.

1. Terminal mode
By operating the D-STAR transceiver through the Android device you can contact other D-STAR transceivers.
In the Terminal mode the transceiver will not transmit an RF signal even if [PTT] is held down because the microphone audio signal is transmitted through an Internet LTE or 5G network.

2. Access Point mode
In this mode the D-STAR transceiver functions as a Wireless LAN access point.
The D-STAR transceiver repeats the received signal from the Android device to other D-STAR transceivers.
Refer to the instruction manual (PDF) for setting details. The instruction manual can be downloaded from the ICOM web site.
(URL: http://www.icom.co.jp/world/support/download/manual/index.php)

[Device requirements]
1 Android 8.0 or later
2 Touch screen Android device
3 Bluetooth function and/or USB On-The-Go (OTG) host function
4 Public IP address

[Usable transceivers] (As of March 2026)
Transceivers that can be connected via USB
- ID-31A PLUS or ID-31E PLUS
- ID-4100A or ID-4100E
- ID-50A or ID-50E *1
- ID-51A or ID-51E (PLUS2 only)
- ID-52A or ID-52E *1
- IC-705 *1
- IC-905 *1
- IC-9700

Transceivers that can be connected via USB or Bluetooth
- ID-52A PLUS or ID-52E PLUS *1 *2

* When connecting via USB a separate data communication cable is required.
*1 Supported in RS-MS3A Ver.1.31 or later.
*2 RS-MS3A Ver. 1.40 or higher supports Bluetooth connection.

Note:
- This application operates on Android devices as a gateway server on the D-STAR system. Therefore a public IP address must be set on either the Android device or the Wireless LAN router.
- Ask your mobile carrier or ISP for a public IP address. According to the contract communication charges and/or communication packet limits may occur.
- Ask your mobile carrier ISP or manufacturer of your Android device or router about public IP setting details.
- ICOM does not guarantee the RS-MS3A will function with all Android devices.
- Turn OFF the Wireless LAN function when communicating through an LTE or 5G network.
- The RS-MS3A may not be usable due to conflicts with other applications installed on your Android device.
- The RS-MS3A may not be usable even if your Android device supports the USB OTG host function.
- Depending on your Android device the power that is supplied to the USB terminal may be interrupted while in the display sleep mode or the power saving mode. In that case remove the Screen timeout check mark on the Application Setting screen of the RS-MS3A. Set the sleep function on your Android device to OFF or to the longest time period.
- Operate your transceiver with the RS-MS3A in compliance with appropriate regulations.
- ICOM recommends that you operate them with a club station license.