iotivity - skkumonet.skku.edu/wp-content/uploads/2015/10/iotivityframework.pdf · iotivity demo...

Networking Laboratory 1/00

Sungkyunkwan University

Copyright 2000-2015 Networking Laboratory

IoTivity

Presenter: Dzung Tien Nguyen

Networking Laboratory, 83345

[email protected]

mailto:[email protected]

IoTivity demo Networking Laboratory 2/37

Current issues

Incompatibility of platforms: Manufacturers are providing a large number

of IoT devices. Those devices could be based on Linux, Android,

Adruino, iOS, etc. To let them work together requires a hub/controller to

interpret (or ‘translate’) the data, commands.

Difficulty in cooperation between industries (smart home, automotive,

industrial automation, healthcare etc.)


IoTivity target To provide a common open source framework for Discovery and

Connectivity. In addition to that, Device management and Data management are mentioned as services

To ensure interoperability among products and services, regardless of maker and across multiple industries, e.g. Consumer, Enterprise, Industrial, etc. The interaction might be made between WIFI, Bluetooth, Zigbee, Z-wave devices and so forth

To provide the common code bases/APIs to accelerate innovation, besides the open standard and specifications

Supporting Linux (compiled), Android (Compiled), Tizen, Adruino, Yocto, iOS, Windows (unsuccessful)


The framework


The stack architecture


Protocol: CoAP

Is Constrained Application Protocol for constrained resource

environment

Is a simple and compact binary mapping of REST

Provides asynchronous notifications, publish-subscribe, resource

discovery

Work in CLIENT/SERVER context

Each entity can be both CLIENT/SERVER at

the same time

IoTivity is using CoAP

http://iot-datamodels.blogspot.kr/


Most IoT systems use UDP. However, since UDP is neither stable nor reliable, it needs to combine with another application protocol to improve the stability

CoAP stands for Constrained Application Protocol, is a client-server application layer protocol designed for resource-constrained devices (i.e. low power, small, need to control remotely)

CoAP is like HTTP (document transfer protocol), but with multicast, low overhead and simplicity.

CoAP can easily be translated to HTTP. CoAP is built on top of UDP (not TCP) and supports the scalable web services

More about CoAP


Resource Discovery


CoAP: observation

CoAP extends the HTTP request model with the ability to observe a

resource.

► When the observe flag is set on a CoAP GET request, the server may

continue to reply after the initial document has been transferred.

► This allows servers to stream state changes to clients as they occur. Either

end may cancel the observation.

Example of a resource: a light controller, a garage door opener

► Resources might be organized in a hierarchical manner (tree form)

E.g. /fridge/ Light1

Light2

Fan

Sensor1

Sensor2


More on IoTivity

Current release: 0.9.2, open source

Getting started: https://www.iotivity.org/documentation/linux/getting-

started

Number of joined companies: 50+, including Intel, Samsung, …

Still in development phase, not a production-ready product

Discussion forum:

► https://jira.iotivity.org/browse/IOT-124

► View is available

► Registering seems not open

https://www.iotivity.org/documentation/linux/getting-started

https://jira.iotivity.org/browse/IOT-124


The virtual machine

Ubuntu 14.04

Username/passwd: mc2015/123

Gcc4.9

Eclipse with Android SDK v.19 / 20 / 21 (required); Android NDK, Gradle

Dependencies:

► python2.7, scons

► Jre

► Boost, …


Build the framework

Source code inside the VM is prebuilt with the following options:► scons TARGET_OS=linux TARGET_ARCH=x86 TARGET_TRANSPORT=IP

► scons TARGET_OS=android TARGET_ARCH=armeabi TARGET_TRANSPORT=IP

To add more source file (e.g. to folder resource/examples) and

recompile:

► Inside the folder, modify Sconscript

► From root directory execute:

scons resource/examples


Before getting started

Generating the doxygen► doxygen –g iotdoc

► vim iotdoc

RECURSIVE=YES

CREATE_SUBDIRS=YES

GENERATE_LATEX=NO

► doxygen iotdoc


Client/Server basis

Server

► Init the configuration

► Register resource

Entity handlers for handling request (GET/PUT/POST/OBSERVE)

Client

► Client configuration

► Functions for PUT/GET/POST/OBSERVE and its callbacks


InitOICStack config

Initialize the configuration mode of the ‘thing’► ServiceType: InProc, OutOfProc

► ModeType: Server/Client/Both

► IPAddress: 0.0.0.0 means broadcast

► ClientConnectivityType: port number

► QualityOfService: LowQoS, MidQos, HighQos, NaQos (in

OCApi.h)


[SERVER] Define a resource

Member variables

Constructor


[SERVER] Register the resource

C++ API► OCStackResult OC::OCPlatform::registerResource(…);

► OCEntityHandlerResult

entityHandler(std::shared_ptr<OCResourceRequest> request)


Application calls the library function

On finishing the task, the library function trigger the associated callback

at the same tier with the call


Find Resource On the findResource(), the get() request is sent out (multicast) to

all the vicinity IoT devices

Each device processes the query and responds if it satisfies the request

filter

Parameters: "oic/res?rt=core.light" including URI path (“/oc/core”) and URI query (“rt=core.light”)

► “/oic/res” is the OIC Virtual resources supported by every OIC device

(octypes.h)


Scheme 1: Simple discovery

myClient myServer

Register resource

findResource()

GET

onGetCallback()

foundResource()OCResource

OCRepresentation

get()


[CLIENT] Find Resource FindResource syntax

FindResource ‘s Callback

std::ostringstream requestURI;

requestURI << OC_RSRVD_WELL_KNOWN_URI << "?rt=core.light";

OCStackResult result = OCPlatform::findResource("",

requestURI,

CT_DEFAULT, FindCallback);

void foundDevice(std::shared_ptr<OCResource> resource){if(resource){

std::cout << "Got one" << resource->host() << resource->uri() << std::endl;

} }

//host() return string coap://<m_devAddr.addr>:<m_devAddr.port>//source: OCResource.cpp


[Client] Get

Trigger GET request

Process onGetCallback

OCStackResult result = resource->get(getMap, g);if(OC_STACK_OK != result){std::cout << "Get resource error!" << std::endl;}

void onGetCallback(const HeaderOptions& hO, const OCRepresentation& rep, const int eCode){

if (eCode == OC_STACK_OK){std::cout << "GET request was successful" << std::endl;std::cout << "\tPower value: " << rep.getValueToString("power")

<< std::endl;}else{

std::cout << "Error in GET callback" << std::endl;}

}


[SERVER] OnGetRequest On receiving GET request, the resource server get() its

representation and sendResponse back to the requester using

OCPlatform API

if (requestType == "GET") {std::cout << "\tReceived GET request\n";pResponse->setResourceRepresentation(lightResource::get()); if(OC_STACK_OK == OC::OCPlatform::sendResponse(pResponse)) {ehResult = OC_EH_OK;}

}


Scheme 2: PUT request

myput myServer

put()

GET

onGetCallback()

onPUTCallback()OCResource

OCRepresentation

get()

entityHandler

(requestType == “PUT”)


[CLIENT] PUT

PUT is to send the next state to the resource

Send the new desired state of type OCRepresentation to the resource

//do the PUTOCRepresentation repToPut; repToPut.setUri("/a/light"); for (auto i = 0; i < 10; i++){

if (i%2 == 0)repToPut.setValue("power", std::string("off"));

elserepToPut.setValue("power", std::string("on"));put(myClient::lightResources, repToPut);

sleep(3);}


Scheme 3: OBSERVE request

myput myObserverServer

put()

- entityHandler(requestType == “PUT”)

- notifyObserver()

myObserverClient

findResource()

and Observe()

Get server’s state changes


Usecase: send other

In IoTivity, devices are in CLIENT/SERVER modes, and the

connections are of type Client-Server

► The available messages are GET/PUT/POST/OBSERVE

Look at the signature of those functions:

In OCApi.h: typedef map::<string, string> QueryParamsMap;

OCStackResult OCResource::get(const QueryParamsMap &, GetCallback attributeHandler)

OCStackResult OCResource::put(const OCRepresentation & representation,const QueryParamsMap & queryParametersMap,PutCallback attributeHandler)

OCStackResult OCResource::post(const OCRepresentation & representation,const QueryParamsMap & queryParametersMap,PostCallback attributeHandler)

OCStackResult OCResource::observe(ObserveType observeType,const QueryParamsMap & queryParametersMap,ObserveCallback observeHandler)


With OCRepresentation which will be sent back to the client, we can

carry any data with user-defined field name

► In the example, “power” is the field name

Back to OnGetCallback

void onGetCallback(const HeaderOptions& hO, const OCRepresentation& rep, const int eCode){if (eCode == OC_STACK_OK){

std::cout << "\tPower value: " << rep.getValueToString("power") << std::endl;

}else{

std::cout << "Error in GET callback" << std::endl;}

}


Scheme 4: user-defined GET

myQueryClient

myQueryServer

get()


To be modified

Add extra info to GET message

Add energy level to resource’s representation

QueryParamsMap getMap;getMap["energyLevel"] = "100";getMap["IP"] =

myClient::myIP4Address;

l_rep.setEnergy("energyLevel", l_energy);


Extract info

From server side: calling API to get the queryParams of type

std::map<string, string>

Client:► Ocrepresentation.getValueToString(“energyLevel”)

std::string requestType = request->getRequestType();std::map<std::string, std::string> queryParams = request->getQueryParameters();auto requestRepresentation = request->getResourceRepresentation();

for(auto it = queryParams.cbegin(); it != queryParams.cend(); it++){

std::cout << it->first << " : " << it->second << std::endl;// it->first = Text “energyLevel”// it->second = the actual value

}


Approach to the project

Creation of an array for storing resources in the vicinity

Requesting residual energy from neighbors, selecting the highest (e.g.

using GET)

Utilizing the PUT message to send data to an end point

► Defining new field in the OCRepresentation

(e.g. “mode” = “aggregation”/”put”)

► On the server side:

Making your aggregation algorithms (e.g. taking average of all the

“Temperature” received) and then sending to the sink

if (requestType == "PUT") {recvmsg = request->getResourceRepresentation();if (recvmsg.getValueToString("mode") == "aggregation") {

//do something here}

}

Networking Laboratory 33/00

Sungkyunkwan University

Copyright 2000-2015 Networking Laboratory

Things-manager

Extra example


Guideline link

Follow this link:

https://wiki.iotivity.org/getting_started_iotivity_services_for_android_0_9

_1

Path for android SDK:

► Iotivity/extlibs/android/sdk/android-sdk/

Path for android NDK:

► Iotivity/extlibs/android/ndk/android-ndk/

Link for installing android plugin for eclipse:

► https://dl-ssl.google.com/android/eclipse/

https://wiki.iotivity.org/getting_started_iotivity_services_for_android_0_9_1

https://dl-ssl.google.com/android/eclipse/


Topology

Context:

► All the devices connect to the Access point

► Light resources <mcl1> and <mcl2> registered

► Android clients interacts with the resources:

PUT, OBSERVE

Scheduled PUT

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