WisMesh 1W Booster Starter Kit targets high-power Meshtastic solutions

RAKwireless WisMesh 1W Booster Starter Kit is a high-power Meshtastic solution based on Nordic Semiconductor nRF52840 wireless SoC, Semtech SX1262 RF transceiver, and SKY66122 power amplifier for extended mesh range.

It’s built from three modules from the WisBLock IoT ecosystem, and besides a power amplifier for longer Tx range and better penetration through walls, it also features an integrated RF filter for enhanced reception performance. It offers an alternative to the LILYGO T-Beam 1W with an ESP32-S3 + Semtech SX1262 LoRa transceiver +  PA+LNA design, which we covered just last week.

WisMesh 1W Booster Starter Kit specifications and technical details

WisMesh1W Booster Starter Kit content and specifications:

• WisBlock RAK3401 Core module
  • SoC – Nordic nRF52840
    • CPU core – Arm Cortex-M4F @
    • Memory – 348KB SRAM
    • Storage – 1MB Flash
  • I/O ports – UART/I2C/SPI/ADC/GPIO
• WisBlock RAK13302 1W LoRa transceiver module
  • Semtech SX1262 LoRa transceiver
  • SKY66122 signal booster
  • Integrated RF filter for enhanced reception performance
  • IPEX antenna connector for LoRa
  • Support for 9xx MHz frequency band
• RAK19007 WisBlock Base Board
  • 4x sensor slots for WisBlock Sensor Modules
  • Supply voltage
    • 5V over USB
    • 5V over Solar Panel connector
    • Rechargeable battery
• Accessories
  • WiFi/BLE antenna
  • 900Mhz LoRa antenna
  • USB cable
  • IPEX to SMA cable for LoRa Antenna
  • SMA Rubber LoRa Antenna
  • 2x 5V supply cables
  • Screw set
  • Quick Start Guide

The company mentions that “due to the high power consumption of the 1W transceiver, the RAK13302 cannot work from the 3.3V supply voltage”. The kit requires using a battery with the WisBlock Base Board, an external 5V supply for the RAK13302 module through its own power supply connector, and constant powering from USB.

Users can check out the getting started guide for kit assembly and Meshtastic firmware flashing instructions. RAKwireless also shared a table showing the current draw at 3.7V and PA power at different frequencies when configuring the SX1262 from 22 dBm down to 0 dBm. The maximum power is relatively constant at around 30 dBm (about 1 Watts) at 902.9 MHz, 915.2 MHz, and 924.5 MHz frequencies.

RAKwireless shared a use case where a field technician evaluated environmental sensor communication across a 4km site using the WisMesh 1W Booster Starter Kit, and tests showed 35% stronger signal retention, 98% packet delivery, and repeatable performance during five field trials.

The company also shares a comparison table with other 1W LoRa solutions, which didn’t include the latest LILYGO T-Beam 1W, but instead the ESP32-based The Hammer (1W) and Hydra 1W Board, the MeshAdv Pi-HAT (1W), and the Sparkfun 1W Breakout designed to connect to an MCU board of your choice.

User responsibility and regulations for 1W operation

I asked a few questions about regulations to RAKwireless. They answered that while 868 MHz at 1W is not allowed in the EU, this doesn’t mean it’s disallowed in all countries, and some may permit it under certain regulatory requirements specific to that country. It’s the responsibility of the users to comply with the limits imposed by their home country’s regulations. 9xx Mhz at 1W is allowed in the US, but it could be different for other countries, and there’s no one-size-fits-all setting in the firmware to make sure the product is operated legally within one country. The power and duty cycles have to be set by the user.

Since the company offered us the opportunity to review the WisMesh 1W Booster Starter Kit on CNX Software, I looked into more details about what it would take to do so legally in Thailand. I first went the lazy way and asked a LoRa specialist whether he wanted to review it, and he answered quickly within 5 minutes:

I am unable to test LoRa signals with a transmit power of 1 watt or 30 dBm EIRP because it high power transmission, so must be permission to possess and use this device must be obtained from the NBTC (National Broadcasting and Telecommunications Commission), which involves complex and costly procedures.

RAKwireless also shared a link to a relevant Meshtastic firmware issue pointing to relevant NTBC regulations (Thai language only) governing LoRa/LoRaWAN usage in Thailand. Here’s the main table relevant to our use case.

The good news is that Thailand’s regulations allow for up to 4W transmissions in the 920 – 925 MHz frequency band used by LoRa. The devil is in the details, and here’s a rough translation of the part in red:

• Up to 50mW E.I.R.P – Trading license required
• Up to 500 mW E.I.R.P – Trading, manufacturing, and import licenses required
• Up to 4000 mA E.I.R.P – Possession, utilization, trading, manufacturing, import, export, and installation licenses required

Another requirement is that any transmission over 50mW must also be operated with a 10% duty cycle. The original poster also notes the following about licenses:

Regarding licensing, this refers to device type approval, i.e., certification that the device complies with the specified frequency band and duty-cycle limits. It is not an individual/operator license.

About practical usage, for our enterprise and government deployments, the firmware builds from this repo I compile already set the TX preset to 20 dBm in code. I’m proposing this as an enhancement to the official Meshtastic configuration so it’s available out of the box for Thailand.

More broadly, I’m also working with stakeholders, politicians to modernize the regulations around devices in the 920–925 MHz band (e.g., LoRaWAN and other protocols). Several requirements are outdated and don’t align well with real world IoT deployments, so updates would meaningfully improve compliance and interoperability.

As I understand it, there’s no need to have a license to operate such a device, and the main challenge would be importing the WisMesh 1W Booster Starter Kit into the country, after which we could just use it legally with the proper settings: AS923 and 10% duty cycle. We can’t even import a consumer router sample cost-effectively, so we’re not going to try with this type of high-power LPWAN device. However, if a reseller imports it in Thailand and distributes it, we might consider it.

Availability and pricing

RAKwireless sells the WisMesh 1W Booster Starter Kit for $39 on its online store. It might also eventually become available on the company’s AliExpress and Amazon stores.

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