Introduction
This enabler defines the application layer communication protocol between a LWM2M Server and a LWM2M Client, which is located in a LWM2M Device. The OMA Lightweight M2M enabler includes device management and service enablement for LWM2M Devices. The target LWM2M Devices for this enabler are mainly resource constrained devices. Therefore, this enabler makes use of a light and compact protocol as well as an efficient resource data model.
A Client-Server architecture is introduced for the LWM2M Enabler, where the LWM2M Device acts as a LWNM2M Client and the M2M service, platform or application acts as the LWM2M Server. The LWM2M Enabler has two components, LWM2M Server and LWM2M Client. Four interfaces are designed between these two components as shown below:
- Bootstrap
- Client Registration
- Device management and service enablement
- Information Reporting
This architecture is shown in Figure 1. The LWM2M Enabler uses the Constrained Application Protocol (CoAP) with UDP and SMS bindings. Datagram Transport Layer Security (DTLS) provides security for UDP transport layer. The LWM2M Enabler protocol stack is shown in Figure 2.
Figure 1: The overall architecture of the LWM2M Enabler.
Figure 2: The protocol stack of the LWM2M Enabler.