1. Developing IoT endpoints with mbed Client
Eric Yang / Staff Engineer / ARM
ARM mbed Connect / Shenzhen, China
December 5, 2016

2. Agenda ARM mbed Client introduction
Connecting endpoints with mbed Client
Managing endpoints with mbed Client
Maintaining energy efficiency
End-to-end security with mbed Client
Porting mbed Client to endpoints
Summary

3. mbed Client introduction

4. mbed Client & mbed Connector
mbed Client is an implementation of the LWM2M client, and the mbed Connector implements the LWM2M server
mbed Client communicates with mbed Connector via CoAP messages
mbed Connector interacts with Web services and apps using a REST API

5. mbed Client scope
mbed Client is a portable embedded software library that links IoT devices with mbed Device Connector, providing the infrastructure to connect endpoints with cloud apps
mbed Client is provided free for IoT device manufacturers
A complete set of libraries
High level C++ API
Porting guidelines and examples
Apache 2.0 license

6. Connecting endpoints
with mbed Client

7. mbed Device Connector: Making IoT scale
mbed Device Connector eases development, management and scaling of IoT
Available at connector.mbed.com – easy transition to commercial service providers
The mbed Device Connector service provides mbed developers with a simple, secure and energy efficient way to connect mbed-enabled devices to the cloud. It provides connectivity that is secure and built for constrained IoT devices. Devices are then available through REST APIs to enterprise software, web applications and cloud stacks. 
Build application
with example code
Build IoT Device
Connect your devices

8. Bootstrapping IoT devices
Factory bootstrap according to OMA LWM2M standard
Create the keys in the webpage
Copy-and-paste them into the relevant file
Bootstrapping of devices enables to configure a secure channel between device and mbed Device Connector

9. LWM2M data traffic
Turn any device into an endpoint to use with mbed Device Connector
Device initiated
IoT devices provide sensor readings and configuration information, to a cloud-based platform
Service initiated
Actuators receive instructions from users routed via the cloud infrastructure

10. Managing endpoints
with mbed Client

11. mbed Client interfaces for device management
mbed Client allows full control and monitor of endpoint and applications
Registration and deregistration
Register the Client and its Objects
Device management and service enablement
Server access to Object or Resource
Information reporting
Observe and get notifications of new Resource values

12. Object and Resource model
Object & Resources can each can have Instances
An Object is a collection of Resources
A Resource is an atomic piece of information that can be read, written or executed
Access control list (ACL) control access to objects accessed by LWM2M Servers
©Sensinode 2013

13. Powerful model
Provides application semantics that are easy to use and re-use
Standard device management Objects already defined by OMA
Other SDOs or enterprises can define & register Objects
Global registry and public lookup of all Objects
OMA LWM2M object & resource registry information/omna/lightweight-m2m-lwm2m-object-registry

14. Maintaining energy efficiency

15. IoT energy constraints
Power consumption is one of the key constraints for the IoT devices
Use battery or energy harvesting source for power which further constraints hardware, software and the communication protocol usage
Important to keep the device in sleep mode when not sensing or communicating data

16. Constrained Application Protocol (CoAP)
CoAP is optimized for small message delivery
Uses binary encoding and binary headers
Utilizes UDP
Adds reliable message delivery to UDP
Queue mode – sleeping node
For energy efficiency reasons many IoT devices are on sleep most of the time
Queue mode enables LWM2M server to queue the request until the device wakes up

17. From Web Applications to IoT Nodes
1000s of bytes
Web object
100s bytes
10s of bytes
Proxy
Binary web object
Router
Binary web object
CoAP
CoAP
DTLS / UDP
HTTP
Constrained Application Protocol (CoAP)
CoAP is optimized for small message delivery
Uses binary encoding and binary headers
DTLS / UDP IP
6LoWPAN
IoT node network
IoT backhaul
TLS / TCP IP
Web application

18. Sleeping nodes & energy efficiency
(1)
Sleeping nodes & energy efficiency
Easy to interact with devices that are always connected
For energy efficiency reasons many IoT devices sleep most of the time
Client uses the registration refresh message to inform LWM2M server that it is awake and ready to receive messages
Server conveys messages to client within a given time window
(3)
(2)
(4)
(5)

19. Sleeping nodes & energy efficiency
Easy to interact with devices that are always connected
To save energy client registers to server in Queue Mode and goes offline
Server queues operations when client is asleep
Client uses the registration update message to inform server that it is awake and ready to receive messages
Server conveys queued messages to client within a given time window
For energy efficiency reasons many IoT devices are on sleep most of the time
Queue mode enables LWM2M server to queue the request until the device wakes up

20. End-to-end security
with mbed Client

21. mbed Client security
LWM2M defines a strong security solution for authentication of the end points and data channel protection
DTLS v1.2 security for all CoAP communication
mbed Client uses X.509 certificates to authenticate DTLS keys
Per Server and Object instance access control using ACL objects
Bootstrapping for complete provisioning and key management

22. mbed TLS for mbed Client
mbed TLS makes it easy for developers to include cryptographic and TLS/DTLS capabilities in their embedded products, with a minimal code footprint
mbed Client provides an API to set up entropy and RNG functions for the underlying TLS to enhance robustness and security
Full API documentation available
Open Source under Apache 2.0 license at
Suitable for use on Cortex-M and Cortex-A targets

23. Porting mbed Client
to endpoints

24. mbed Client scalability objectives
Enable management of all connected devices within a single management system
Support mbed Client porting across a wide spectrum of hardware platforms and embedded operating systems of a very fragmented IoT market
Enable smooth and swift porting of mbed Client capabilities for ARM partners

25. Platform Abstraction Layer
mbed Client
mbed OS
RTOS

26. Platform Abstraction Layer
New release
mbed OS
RTOS

27. Platform Abstraction Layer
Contain porting effort within a single layer of platform dependent interfaces, which can be implemented by partners
Platform Abstraction Layer
mbed OS
RTOS

28. mbed Client library PAL interfaces include: Threads
Application and service integration
mbed Services Client Library
mbed Client C++ API
Device Connector support
LWM2M
PAL interfaces include:
Threads
Synchronization objects
Kernel ticks, timers
Memory-pool
Message-queue
IP networking
CoAP
mbed TLS
Platform Abstraction Layer
PAL implementation
PAL implementation
Custom Embedded Platform
(Metal/RTOS/Linux, Networking)
PAL implementation
Custom Embedded Platform
(Metal/RTOS/Linux, Networking)
Custom embedded platform
(mbed OS / RTOS / Linux)

29. Summary

30. mbed Client Connect Management Productivity Efficiency Security
Addressing the complexity of reliably connecting high volumes of diverse devices across different networks
Management
Enabling scalability through interoperability across the supply chain
Productivity
Portable to any device allowing management of all connected devices on a single system and fast time to market
Efficiency
Optimized for constrained environments and sleepy nodes
Security
Trust through end-to-end security, by providing confidentiality, integrity and authentication

31. Useful links mbed Client libraries, example code, and documentation
mbed Client source code
mbed Client example:
ARM mbed developer site:
OMA LWM2M object & resource registry
m2m-lwm2m-object-registry

32. Thank You!