LTE-M or NB-IoT, that is the question…


  • Deutsche Telekom IoT

    Hey IoT Creators,

    As you may noticed, DT has recently completed the roll out of the LTE-M network in Germany, while other countries of DT’s footprint continue their rollout activities at the moment. LTE-M is yet another 3GPP LPWA technology, therefore we’d like to provide you with a better understanding on this network, especially when compared to NB-IoT.

    Below you will find a summary of key advantages and features:

    1. Like NB-IoT, LTE-M supports lower energy consumption:
      • Optimized Chipset-Design focused on relevant radio technologies (e.g. no MIMO)
      • Lower Power-Class of modules (20dBm)
      • Reduced Signaling and more efficient data transmission
      • Low-Power Features (PSM, LP-TAU, eDRX)
    2. Deep indoor coverage is also applicable for LTE-M:
      • High Transmission Power Density: radio transmission over a narrow-band carrier with a spectrum bandwidth of only 1,4 MHz
      • Coverage Enhancement (CE) / Mode A and Mode B allow for message repetitions
    3. LTE-M has impact on low cost of materials:
      • Half-Duplex mode supported
      • Unnecessary LTE-Features not supported (such as Carrier Aggregation, Dual Connectivity, Device-to-Device Services)
      • Intra-RAT not required (seamless transition between radio technologies, e.g. GSM, 3G, LTE)
      • Single antenna needed
    4. Last but not least, hand-over between LTE-M cells is supported (intra-frequency and inter-frequency from 3GPP Rel. 14)

    Application of each network technology is highly dependent on the use-cases and therefore should be carefully considered.

    Have you been considering LTE-M based solutions for your projects? What of those features are important for your projects and in which of your use-cases LTE-M would be preferable comparing to NB-IoT? Shout out in the comments below and also sign-up if you want to get an early access to LTE-M in IoT Creators ‘Thing’



  • @Roman-Dyzhyk

    LTE-M is a good decision for multiple reasons:

    • It supports HTTP(S) so I can directly reach my cloud endpoint without the need to build new CoAP/UDP proxies.
    • Roaming. Virtual MNO’s like ibasis offer great coverage for LTE-M in many countries with a single SIM. This saves a lot of headache for global products. I have yet to see a similar offer for NB-IoT.
    • Larger data bundles. Generally LTE-M data is cheaper and can be bought in larger quantities. This means I can ocasionally roll out an update without blowing up my data bundle.
    • It supports most low power features (except RAI) and increased coverage benefits.

    The biggest advantage I see today for NB-IoT is ability to use release assist (RAI). RAI has proven to be the biggest energy saver for simple TX only sensors and the fact none of the LTE-M networks or modules supports it is a major drawback for LTE-M. I understand this will be adressed in coming 3GPP releases but those are months if not years away. The fact that RAI is available today for NB-IoT means it will always beat LTE-M in energy consumption.


  • Deutsche Telekom IoT

    @Stefan-de-Lange, thanks for sharing it! Very much helpful and we will collect some more feedback in following weeks to provide for the interested users LTE-M access, so they can try currently available features



  • After doing some testing, (albeit not here in the UK!) for our use case (electric vehicle charging stations) we’ve come to the conclusion that LTE-M is the way forward for us:

    https://www.v2g-evse.com/2018/09/29/what-are-the-top-iot-platform-requirements/

    NL and DE are target markets for us, so in the (continuing!) absence of a UK wide LTE-M network testing across the North Sea beckons yet again!

    Jim


  • Deutsche Telekom IoT

    @Jim-Hunt thanks for the comment. What exactly influenced on your conclusion that LTE-M is the way forward: any specific features or requirements for your projects? Interesting to learn more details (if you can share) https://iotcreators.com/en/lte-m-access/



  • @Stefan-de-Lange IMHO is it possible to do HTTP(S) over NB-IoT, however T-Mobile decided to limit the messages to 512 bytes, use UDP and not to allow connections to the public internet. I think it would be nice to do HTTP(S) over NB-IoT



  • Hi @Roman-Dyzhyk,

    For a bit more information see also:

    https://www.v2g-evse.com/2018/08/06/department-for-transport-invests-in-v2g-evse/

    I sit on the relevant international standards development committees. For this use case (IEC 63110) the committee has specified TCP as a requirement.

    Q.E.D?

    One “real world” example. How do you perform “over the air” firmware updates using NB-IoT?


  • Deutsche Telekom IoT

    @JeroenD said in LTE-M or NB-IoT, that is the question…:

    HTTP(S) over NB-IoT, however T-Mobile decided to limit the messages to 512 bytes, use UDP and not to allow connections to the public internet. I think it would be nice to do HTTP(S) over NB-IoT

    At least you can always do http(s) from IoT Creators portal to your application 😉



  • @JeroenD I don’t think it’s possible to do TCP/IP over NB-IoT and therefore it’s also not possible to do HTTPS. Atleast not on the networks I have used, maybe it’s supported from the standard point of view. The 512 byte limit is not coming from T-Mobile but from the standard. TCP/IP is a very inefficient protocol for IoT in both data and energy consumption so not a good choice for NB-IoT. It will consume a lot of energy because many bytes are transported and the bitrate is very low. That’s why it’s a better fit for LTE-M



  • @Roman-Dyzhyk This is okay for UDP, but what about LWM2M?


  • Deutsche Telekom IoT

    Hi,

    I did “normal” TCP/IP MQTT on top of NB-IoT connection with the Quectel BC66. So TCP/IP is possible. But I didn’t try to post a normal HTTP request.

    LWM2M is implemented on top of CoAP and UDP. By this it works perfectly on NB-IoT. It is also supported by Quectel BC66. We tested it successfully with Eclipse Leshan server and the Nokia Impact LWM2M server.

    Regards, Roland