The wM-Bus or Wireless Meter Bus is a European standard (EN 13757-4) that defines communication between usability meters and data loggers, hubs or intelligent meter gates. Based on the M-Bus wireless bus, a new advanced measurement infrastructure (AMI) was developed to meet the needs of media meters across Europe. Several years have passed since M-Bus and sub-GHz wireless connections were introduced, but they are still evolving in response to changing environments and taking advantage of technological advances, including the emergence of the Internet of Things.

2.4 GHz band vs unlicensed bands

Wireless communication over long distances is a requirement for intelligent network devices. These frequencies are unlicensed and provide better radio wave propagation than 2.4 GHz. In Europe, the most common frequencies are 868 MHz, 434 MHz and 169 MHz. These unlicensed bands can be used to reach difficult areas, such as underground meters or the location of buildings with many walls and obstructions. In addition, utilities have lower solution costs when operating in the unlicensed band.

COVID-19 and wireless technologies

The use of wireless technologies during COVID-19 pandemic hazards is often a necessity, to prevent the virus from spreading. One of obvious choices for Internet of Things and home monitoring is Wireless M-Bus implementation.MODUINO series expansion options now include TECHBASE’s high-performance Wireless M-Bus module.

For low power applications using either the specifically allocated 169 MHz metering band or the 868 MHz ISM band, the module can be configured as an embedded micro system or simple data modem. For Industrial IoT applications, the device can be configured for interoperability in a WMBus network.

In terms of covered area and power consumption, the RF implementation ensures best-in-class performance. On the 169 MHz band, the output power can be increased up to +30 dBm (+27 dBm on the optimized version for maximum power efficiency) and up to +15 dBm on the 868 MHz band. The extremely reduced power consumption gives access to long lasting battery life requirements (up to 2 μA in sleep mode for wireless M-Bus modules with an RTC clock running).

It is possible to make Moduino devices equipped with a WMBus stack that Embit developed specifically for the ESP32 platform, allowing them to be integrated in any desired system, without effort, and simplifying interactions in WMBus networks.