A.1 Introduction

OMA Lightweight M2M is a protocol for device and service management for M2M. The main purpose of this technology is to address service and management needs for constrained M2M devices, over UDP and SMS bearers.

Note

This annex provides an overview of the LWM2M protocol. The authoritative source for the protocol is provided by the LWM2M Technical Specification [3].

The crucial aspects in this work are the:

• Target devices for this protocol are resource constraint devices (e.g. 8-16bit MCU, RAM is in tens of KB and flash is in hundreds of KB).
• Ability to perform Data collection and remote control of devices without the need for complex computing and UI operations.
• Optimization of network resources to allow a large numbers of devices may be connected to the communication network simultaneously.
• Fusion of device functionalities management and service manipulation into a single protocol.

From the implementation view LWM2M has the following features:

• Suitable for resource constraint devices.
• Usage of compact binary packets.
• Support for multiple data encoding formats that include Binary , JSON, plain text and opaque data formats.
• Support for reporting information from the Server to the Client when specified condition are met.
• Easy to be implemented though the reuse of existing implementation of IETF technologies : e.g. CoAP.
• (Constrained Application Protocol) for the Transfer Protocol, and DTLS (Datagram, Transport Layer Security) [i.3] for securing the Server/Client exchanges.

One of typical use cases of using LWM2M technology is the firmware upgrade of streetlights [i.4].

• A Streetlights supervisor is responsible for managing the streetlights system. (There are thousands of streetlights in the city and low-cost LWM2M devices embedded in the streetlights.)
• The supervisor needs to remotely upgrade of the firmware of a specific streetlight or a group of streetlights.

Figure A.1-1: Firmware Upgrade of Streetlight of Use Case using LWM2M