NB-IoT module BC68 – the new benchmark

The new ultra-compact BC68 Narrowband Internet of Things (NB-IoT) module has same footprint as the M66 GSM/GPRS module.


NB-IoT module features at a glance

  • Dimensions: 17.7 mm × 15. 8mm × 2.3 mm
  • Pin-compatible with GSM module M66
  • Frequency bands: B1,  B3, B8, B20, B28
  • Communication speed: UL: 62.5kbps by multi-tone
  • 3GPP release 14 with positioning (OTDOA) & Multicast (SC-PTM)
  • SMS, IP / Non-IP communication
NB IoT module BC68

NB IoT module BC68


NB-IoT multi-tone

The NB-IoT standard for single tone transmission is 15.6Kbps. The new BC68 NB-IoT module gives us 62.5 kbs upload using four multi-tones. Multi-tone means that the NB-IoT module will be able to transmit more than one data stream in parallel. The NB-IoT standard offers up to 12 multi-tones with the same 15 KHz subcarrier spacing as LTE. The faster the upload is completed, the lower the power consumption per byte and the faster the channel is free for the next NB-IoT communication package. NB-IoT is in principal a common TDMA communication on a licenced cellular band.


For applications such as street light or smart parking where only a few bytes are transmitted then multi-tone transmission is not required. This job can be done on the Non-IP layer to save power.

Internet of Things Case Study – Smart Waste Bins

Internet of Things Case Study – Street lights

Internet of Things Case Study – Smart Parking

NB-IoT multi-cast

Mulitcast is an interesting feature for firmware updates over the air. Huawei promised us a 100 KB firmware update to a bulk of streetlights with 30 minutes. If there is ever a security bug, then the probelm will be resolved by a mouse click and a cup of coffee.


The OTDOA offer a location accuracy of 50 metres and will charge 200 uAh per location request only. This power consumption is lower than with a common GPS module with its 300 uAh requirement from a cold start. Remember that for a cold start the GPS module will need – 148 dBm. Based on that a cold start indoors may be impossible. NB-IoT is able to generate a position even in a basement. For your information – SIGFOX offers 500 meter accuracy and this is for outdoor only, because SIGFOX is an outdoor network with “lite” indoor coverage only.

NB-IoT module request

Requests for BC68 samples and evaluation kits are welcome. Furthermore, there are more than 30 evaluation kits in combination with the akorIoT radio adapter with NB-IoT module and MCU kit STM32 Nucleo. (www.akorIoT-com). akorIoT + Nucleo = your working IoT prototype.

Has this short article piqued your interest? Do you have a wireless IoT idea? Do you plan an IoT device with embedded antennas or wireless modules? Do you have an IoT prototype and have a need to optimise the design or minimise the price? If you have answered YES to any one of these questions, then please do not hesitate to drop an email to harald.naumann (at) gsm-modem.de and to ask for a proposal or some engineering services to make your IoT idea a cost-effective reality.



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