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    Device management with LightWeight M2M

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    Introduction

    This page explains how to manage your device with AirVantage when using LightWeight M2M.

    Basis

    Overview

    • Who: OMA Alliance Standard

      • Open source protocol; non-proprietary

    • What for: Allow both Device Management and Application Data for constrained devices (sensors or gateways) targeting M2M/IoT

    • How: Based on CoAP (RFC 7252) and DTLS (RFC 6347), UDP-based

    • Why: Standard is much lighter than OMA DM (and TR-069) as it is UDP-based, binary TLV or JSON for resources, increased security

    LightWeight M2M is an API on top of CoAP for:

    • Security provisioning
    • Connectivity configuration, monitoring, statistics
    • Location
    • Firmware Upgrade
    • Software management
    • Error reporting

    Standard objects

    Object Name ID Multiple Instances Description
    LWM2M Security 0 Yes This Object provides keying material for LWM2M Client access to a specified Lightweight M2M Server
    LWM2M Server 1 Yes This Object provides date related to a LWM2M Server
    Access Control 2 Yes Access Control Object is used to check the LWM2M rights to perform an operation
    Device 3 No This Object provides device-related data for a LWM2M Server, plus device reboot and factory reset
    Connectivity 4 No This Object provides monitoring of parameters related to network connectivity (RSSI, Ec/Io, …)
    Firmware Update 5 No This Object enables firmware package installation, and updating performing actions after updating firmware
    Location 6 No The GPS location of the device
    Connectivity 7 No This Object enables client to collect statistics and for LWM2M Server to retrieve this information and set the statistical parameters

    Specific objects

    Specific objects can be defined and registered with the OMA. Sierra Wireless uses 3 custom objects:

    • 10241: Wireless Identifiers
    • 10242: Extended connectivity statistics
    • 10250: ALEOS specific data (modified through AceManager)

    Communication flow

    LightWeight M2M on AirVantage

    AirVantage implements the following LWM2M features

    • Server Provisioning (Bootstrapping)
    • Security

    • Management (Report)

      • Device
      • Performance Network Indicator
      • Location

    • Firmware Update

    • Applications Life Cycle Management

      • Customer applications Remote Update
      • Start/stop customer applications

    Registrations

    Here are some LWM2M Registration Events which can appear in the timeline:

    • Registration: the device sent a registration message to AirVantage: it is connected and is expected to communicate periodically to maintain the registration (configured via the Heartbeat period). The device can send a data in the same message. An observe is automatically sent to be notified for any change about object 10250 (this object is read right after).
    • Registration Update: the device sent a registration update and it is still alive, so should be still connected for the next heartbeat period
    • Registration Expired: the heartbeat period expired and the device didn’t communicate with AirVantage (it is an event, not a message sent by the device)

    The Communications

    Here are some LWM2M Communication Events which can appear in the timeline:

    • Communication: the device opened a session with AirVantage to send data points or acknowledgements:
      • Synchronization: when the device is registered, a new synchronization will be requested (LWM2M read) automatically by AirVantage to send a default list of data (2678 data point communication in the sample timeline). User can manually request synchronization through AirVantage at any time.
      • Report: a report can be defined in AirVantage and the communication policy configured using the ’Configure communication’ button in the system details view to request data (87 data point communication in the sample timeline – Default Status Report)
    • Notification: Data reported using the LWM2M observe mechanism.

    The Commands and FOTA

    Here are some LWM2M Events which can appear in the timeline:

    • Command: If an operation has been created to be executed on the device, at the next connection from the device, this operation is sent to the device (LWM2M execute). Once the operation is acknowledged by the device, the operation is set as finished (success or failure).
    • Writing Settings: If settings operation has been created to be written on the device, at the next connection from the device, this operation is sent to the device (LWM2M write). Once the operation is acknowledged by the device, the operation is set as finished (success or failure).

    Bandwidth Consumption

    • Device & connectivity Synchronization
      • Status Report: 1 220 bytes (56 data) + 1 070 bytes (registration update)
      • Synchronization: 2 372 bytes (166 data) + 1 070 bytes (registration update)
    • FOTA: Major version upgrade (without the binary download).
    • SOTA (without the binary download): 31 506 bytes + binary (78 426 bytes total including a binary of 46 920 bytes)
    • Ping (connected mode):
      • Registration: 1 651 bytes (1 data)
      • Registration update: 958 - 1 070 bytes
    • Command execution with acknowledgement / Setting writing with ack:
      • reboot: 1 328 bytes (registration update included) + 1 651 bytes (registration after reboot)
    • Data sent (with new session):
      • 4 data type like boolean, integer, float, String: 4 591 bytes for 19 data points (with 13 communications + registration update)
      • data history (depends on customer use case, below is just an example)
        • 8 145 bytes to send 56 datapoints for 4 type of data (bool, integer, float and string) + many com for 3 data (object 5)
        • 5 754 bytes to send 562 datapoints for 4 types of data (bool, integer, float and string)
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