A Wirepas 5G Mesh node has two basic architectures:

  • Single-MCU: The application and the Wirepas stack firmware run on the same MCU
  • Dual-MCU: The application and the Wirepas stack run on two different MCU’s. The other MCU might be another microcontroller or for example a gateway unit.

Please take a look more details on the architectures and APIs in [1].

Note! Sections preceded by Warning word will highlight important points that must be understood and respected.

Wirepas Essential Hardware Requirements

Wirepas 5G Mesh v1.0.0 (NR+ Band1) stack firmware is designed to run with Nordic Semiconductor's nRF9161/nRF9151/nRF9131 SiP hardware. The Wirepas 5G Mesh firmware is running in application CPU core and requires Nordic Semiconductor’s NR+ modem firmware which is run in the modem CPU core.

Below chapters are listed the essential HW requirements for a product running Wirepas 5G Mesh v1.0.0 firmware. The nRF9161/nRF9151/nRF9131 SiP related HW requirements are provided by Nordic Semiconductor.

External SPI Flash Memory

In order to enable Nordic Semiconductor NR+ modem firmware to be updated as full modem update using Wirepas OTAP, external flash is mandatory to be included in all the nodes in 5G Mesh network (also in sink node).


  • SPI interface
    • SCK
    • MOSI
    • MISO
    • CS
  • recommendation is to use nRF9161/nRF9151/nRF9131 SiP’s Master SPI interface

Size of the external SPI Flash memory

  • minimum size is 1 MB (to support modem FW OTAP)
    • Note! If external flash is intended to be used for other purposes, the use case is dictating the size of external flash thus the end user need to decide the external flash size (> 1 MB)

nRF9161/nRF9151/nRF9131 SiP IOs are using 1.8V - thus the power supply for SPI flash has to be 1.8V (see [4])

Serial Interface (UART)

The serial interface is needed for the sink node for communication with the gateway host processor subsystem.


  • UART interface
    • RX
    • TX
  • UART pins can be freely selected by HW integrator with the following limitation by Nordic Semiconductor NR+ modem:
    • Warning: check from Nordic Semiconductor which GPIOs are reserved for the ETM debug trace interface - thus these pins should not be used for UART (or some other purposes)

nRF9161/nRF9151/nRF9131 SiP IOs are using 1.8V - thus the power supply for UART has to be 1.8V (see [4])

Programming Interface (SWD)

The initial flashing of nRF9161/nRF9151/nRF9131 SiP is done using the SWD interface. This requires that the nRF9161/nRF9151/nRF9131 SiP SWD interface and nRESET are taken into a flashing and debug connector in the target HW.


  • SWD interface
    • nRESET
    • SWDCLK
    • SWDIO

nRF9161/nRF9151/nRF9131 SiP IOs are using 1.8V - thus the power supply for SPI flash has to be 1.8V (see [4])

The initial programming requires that the modem subsystem and application subsystem is programmed, see flashing guide in [2].

Nordic Semiconductor Essential Hardware Requirements

nRF9161, nRF9131 and nRF9151 SiPs have different requirements and Nordic Semiconductor customer support and documentation will provide the details. In below table it is outlined the main differences between the SiPs.





32.765 kHz Crystal (LFXO)

Integrated to SiP

Integrated to SiP


32 MHz Crystal (HFXO)

Integrated to SiP

Integrated to SiP


Power Management

Integrated to SiP

Integrated to SiP


HW Calibration



Requires AFC and TX power calibration

  • Warning: for starting the hardware design, it is adviced to look Nordic Semiconductor provided documentation and/or contact Nordic Semiconductor customer support for getting the details on the specific hardware design requirements per SiP - also what calibration is needed for each SiP and the tools for R&D phase and production phase testing.

Harmonized Standard EN 301 406-2 Testing

Harmonized Standard testing is defined in ETSI EN 301 406-2. It consists of the radio tests and channel access tests.

Radio tests and needed tools are provided by Nordic Semiconductor. Please contact Nordic Semiconductor for further details on test cases.

Channel access tests and needed tools are provided by Wirepas. See detail in [3].


[1] Wirepas Software and APIs Overview

[2] Your first Wirepas 5G Mesh network

[3] Harmonized Standard (EN 301 406-2) - Channel Access Test Guide

[4] nRF9161 power supply & GPIO power supply

Revision History




06 May 2024


Initial Version

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