By Hannes Tschofenig, Senior Principal Engineer at ARM Ltd. Mr. Tschofenig’s work life is focused on developing standards to make the Internet work better. He has been active in the Internet Engineering Task Force (IETF) for the past 15+ years and has contributed to more than 70 technical specifications on security, privacy, and emergency services.
OMA LwM2M Standardization Update
Two weeks ago the Open Mobile Alliance (OMA) Device Management (DM) Working Group met in Pittsburgh/US to discuss the timeline and features of the LwM2M version 1.1 specification. LwM2M version 1.0 was published in February this year and can be found at http://www.openmobilealliance.org/release/LightweightM2M/V1_0-20170208-A/OMA-TS-LightweightM2M-V1_0-20170208-A.pdf. In addition to the meeting of the DM group a TestFest was hosted by Smith Micro, which was well attended by a wide range of industry players, and took place in parallel at the same venue.
During the three day meeting starting on May 17th the DM group members tried to accomplish three tasks:
- Discuss the timeline and features for LwM2M v1.1. This was the main item of interest for most participants and OMA members have been actively sharing their ideas for new features since early 2017.
- Complete LwM2M v1.0.1. This specification only provides clarifications and will be released soon.
- Explore possibilities to make the standardization process more lightweight.
In this blog post I would like to provide an update on what will happen in version 1.1 of the LwM2M specification.
LwM2M v1.1 Milestones
Whenever we are talking about a new version of a technical specification there is the question about the envisioned timeline. Are we talking about an effort of a year or a multi-year project? The targeted completion date for the LwM2M v1.1 specification is February 2018 (as a so-called “Candidate Enabler”).
More precisely, in the context of the OMA process this means that:
- The consistency review will start on January 2nd 2018. By this time the group needs to have the specification finalized so that all members can read through it and make sure that there are no bugs or loose ends. Hence, the contributing companies have about 7 months time for the work on the specification (ignoring vacation time). This is quite ambitious!
- By February 28th 2018 the specification is approved as a “Candidate Enabler”.
- The final approval (or “Approved Enabler”) happens by the 28th September 2018.
- The time between publishing the specification as “Candidate Enabler” and the final approval is used for organizing two TestFests.
- The features we agreed to cover in v1.1 also have to be written down in a requirements document, which will be published late July 2017.
Needless to say, the test cases for the TestFests need to be written, as well, to take the new features into account. This is planned to be done concurrently with the work on the technical specification.
LwM2M v1.1 Features
The following features are being examined for inclusion in LwM2M v1.1:
- Additional performance optimizations. For example, the CBOR encoding format (RFC 7049) will be investigated, as well as Patch/Fetch (RFC 8132).
- Further security features, DTLS/TLS profiles for IoT (RFC 7925) and end-to-end security are on the list of desired functionality.
- The Working Group is looking at extensions to fully utilize new low power WAN technologies, such as NB-IoT and LoRa. Objects for management of NB-IoT connectivity have already been defined and additional objects for LoRa will be added. Additionally, the support for NB-IoT will be enhanced.
- New use cases, such as the support for non-LwM2M devices managed by a LwM2M-enabled gateway, will be investigated. CoAP over TCP/TLS will also enable LwM2M to be used in networks where restrictive firewalls are deployed.
We are interested to hear your feedback. What features do you care about most?
The specification will be split to separate transports from the LwM2M messaging layer. This allows LwM2M to work more easily over new transports. Other transports, such as MQTT or HTTP, may be added later.
Final Remarks – an Invitation to Join
If you are interested in helping advance the LwM2M specification, consider joining the OMA DM group. Since the work on LwM2M relies on the IETF specifications, contributions to those are also appreciated. Hence, if you have reviewed or implemented CoAP over TCP/TLS or similar specs from the IETF please share your opinion. Finally, if you have feedback to an already released specification, such as LwM2M v1.0, please use the public Github issue tracker at https://github.com/OpenMobileAlliance/OMA_LwM2M_for_Developers/issues.
I will end here with a picture from the Pittsburgh meeting at the Smith Micro office building showing OMA DM Working Group meeting participants as well as some of the participants from the TestFest.