Transcription
White paperInternet of Things:Surviving the machineto-machine protocolsjungle
2Surviving the machine-to-machine protocols jungleIntroductionMQTT, One M2M, AMQP, MT Connect, OPC-UA. There are so manyprotocols that are discussed when talking about machine-to-machine(M2M) and the Internet of Things (IoT). Newcomers struggle to gain a clearunderstanding of them, and even experts find the choice between theseprotocols challenging.Looking at these different protocols raises a number of questions: why arethere so many available? To which technology layers do they belong? Whatare their main differences and similarities? Are they all standardized? Whatare the criteria to use to make the right choice?This White Paper aims to share a few basic but useful principles to help youfind your way.
Surviving the machine-to-machine protocols jungleSummary01 W hy are there so manydifferent protocols?02 T o which technologylayers do the protocolsbelong?03 W hat are the maindifferences betweenthese protocols?3
4Surviving the machine-to-machine protocols jungle01 W hy are there so manydifferent protocols?IoT solutions are provided by a large butfragmented ecosystem of technologycompanies, ranging from startups to largecorporations, and are used in a wide range ofverticals. IoT lies at the crossroads of severalindustries, including Telecommunications,Hardware and Electronic Suppliers, ChipsetManufacturers, Industrial automation and IT.All of these industries started working ontheir own solutions several years ago, eachwith its own considerations and startingpoints, which led to the large number of protocols on the market. All of these players arenow facing the same challenge: offering asimple, cheap, plug-and-play, interoperableand standardized solution to connect different machines and devices to each otherSpecific sectorsand to the cloud. They have approachedthis issue in two different ways: An horizontal approach, with a globalsolution capable of addressing mostindustries. This approach is mainly takenby Telcos; A vertical approach with dedicated solutions designed for specific sectors. Thisapproach is mainly supported by verticalleaders (e.g. service providers for Oil andGas, Manufacturing, etc.). In the case ofmanufacturing, integrated solutions include OPC-UA, MT Connect and TR-50.The following diagram illustrates thissituation and shows how some of thebest-known protocols are MLTEr121Hardwareand ElectronicsIndustryIEEE802.162VerticalIndustryMT ConnectOPC-UATIA TR-50IT PlayersMQTTAMQPLPWALPWA – Low Power Wide Area is a generic term used for new IoT low poser radionetworks as LoRa12a 3GPP key release for 4G cellular communications introducing new IoT featuresan IEEE standardized technology called wimax and now targeting M2M applicationsDiagram 1 - Different M2M and IoT protocols coming from different industries
Surviving the machine-to-machine protocols jungle02 T o which technologylayers do the protocolsbelong?M2M communications involvedifferent technology layers, asshown in the following diagramof the TCP/IP model (it alsoworks with the more complex7-layer OSI model).For a more detailed look atthe TCP/IP model applicationlayer, we can divide the IoTdata protocols in two mainsub-categories: Pure applicative protocols(HTTP, MQTT, AMQP.), And service protocols(OPC-UA, One M2M.).Note that service protocols aredeployed on top of one or several applicative protocols. Forexample, OPC-UA works usingHTTP or AMQP.TCP/IP ModelIoT ProtocolsApplicationOPC-UA, MT Connect, One M2MHTTP, MQTT, AMQPTransportTCP, UDPInternetIPLinkLTE rel12 (cellular),IEEE802.16 (wimax)Diagram 2 - Different IoT protocols involved at different technology layers5
6Surviving the machine-to-machine protocols jungle03 W hat are the maindifferences betweenthese protocols?In this section, we will make three comparisons between different kinds of protocols.HTTP vs MQTT vs AMQPAll of these protocols are purely applicativeprotocols operating over the transport layer(TCP/IP).HTTP (HyperText Transfer Protocol) is awell-known client-server protocol which weuse daily while browsing online. HTTP wasoriginally designed to display web pagesfrom an HTTP server (like Apache) to a webbrowser (like Mozilla). It also enables datasharing between servers, and of course dataexchanges between machines in the M2Mcontext.The main advantage of this protocol is thatit is standardized, well-known, and easyto-use with many of the solutions available(APIs, HTTP servers, HTTP clients, etc.).However, it was not initially designed forM2M communication, leading to sub-optimal performances on tasks like managingsmall messages or real-time communicationbetween many machines.MQTT (Message Queue Telemetry Transport) is a publish/subscribe standardizedprotocol (MQTT v3.1.1). Initially developedby IBM, it is now available in open source.This protocol is well suited to M2M applications that require frequently sharing smallmessages (thanks to a very low overheadratio per message). Many MQTT applications and libraries are available.AMQP (Advanced Message QueuingProtocol) is an open protocol created toshare messages between servers. It offersboth publish/subscribe and point-to-pointmodes. AMQP is known for its performanceon management of very large volumes ofmessages. It was initially developed by JPMorgan Bank, with support from a largeconsortium including Cisco and Microsoft.All of these protocols can be used for M2Mapplications and offer enough functions tosend and retrieve data to and from serversand machines.StrengthsHTTPS tandardized and spread protocol,W ith HTTPS, security can beadequately ensuredMQTTV ery efficient to manage small,frequently shared messagesP ublish/subscribe protocol capable ofhandling one-to-many communicationsAMQPV ery efficient to manage small,frequently shared messagesP ublish/subscribe protocol capable ofhandling one-to-many communicationWeaknessesL ess efficient from a data bandwidthconsumption point of view,Less suitable for IoT networks
Surviving the machine-to-machine protocols jungleNote that the choice between HTTP, MQTTor AMQP is not always available when usinga specific service protocol. For instance, thecurrent implementations of OPC-UA onlysupport HTTP or AMQP.4.1 One M2M vs OPC-UAOne M2M and OPC-UA are not only dataexchanges protocols, but Service LayerProtocols. They also offer a generic architecture, data models and methods, andstandardized APIs. Both use lower-layerprotocols such as HTTP, HTTPS, MQTT,AMQP.OPC-UA is widely accepted and deployedin the manufacturing industry. Most of theautomation HW & solution providers (likesensors, PTC providers, etc.) offer OPC-UAcompliant products, and the protocol allowsinteroperability between products fromdifferent suppliers. It is virtually mandatoryfor manufacturers to use OPC-UA compliantsolutions because the resulting interoperability supports future evolutions of theiroperating landscape and decreases thetotal operating cost of the factory.OPC-UA4.2 One M2Me-HealthManufacturingAs defined by the OPC Foundation, “OPC isthe interoperability standard for the secureand reliable exchange of data in the industrial automation space and in other industries. It is platform independent and ensuresthe seamless flow of information amongdevices from multiple vendors”.Smart Buildings4.3 OPC-UASmart CitiesThe objective is clearly to offer a standardized cross-sector solution that allows M2Mapplications and systems to interoperateand collaborate, regardless of their industry.One M2M is relevant in markets where different verticals need to be interconnected.Smart Cities are a perfect example, sincemany solutions and systems from differentverticals and providers (including publictransportation, connected cars, and smartbuildings) must be interconnected.Public TransportationAs detailed by the One M2M consortium,“the purpose and goal of One M2M is to develop technical specifications which addressthe need for a common M2M Service Layerthat can be readily embedded within varioushardware and software, and relied upon toconnect the myriad of devices in the fieldwith M2M application servers worldwide”.One M2MDiagram 3 - One M2M vs OPC-UA: a choice betweena mono-sector or cross-sector protocolThe choice between service layer protocols(OPC-UA vs One M2M) seems to be drivenby business and strategic decisions (mono-sector activity vs. cross-sector) ratherthan technical considerations.4.4 MT Connect vs OPC-UAMT Connect as presented by the MTConnect Institute “an open, royalty-freestandard that is intended to foster greater interoperability between devices and softwareapplications. By establishing an open andextensible channel of communication forplug-and-play interconnectivity between devices, equipment and systems, MTConnectallows sources to exchange and understandeach other’s data.”7
8Surviving the machine-to-machine protocols jungleConclusionThe reason why multiple protocols exist is due both to the diversity of thetechnology layers they serve and to the fact that different industries startedworking on the same issues a few years ago, delivering different solutions.We are currently witnessing a dual convergence of the protocols:a horizontal convergence (solutions available across different industries)and a vertical convergence (highly specialized solutions for specific sectors).In the case of manufacturing, although competition still exists between MTConnect and OPC-UA, the latter is taking the lead.Choosing a protocol for an M2M project remains complex. This technologychoice should also be business focused, in order to take into considerationall of the functional needs and constraints. This choice will directly impactthe economic performance of applications and the sustainability of anydigital industrial business case.Our 700 Internet of Things and analytics experts can help you in your IoT projectworldwide with Datavenue, our innovative IoT and data analytics modular offer.For more information, please contact us at contact.datavenue@orange.comOrange Business Services is the partner of choice for organizing and implementing the digital transformation of your sales staff’sworking environment. As an integrator and an operator, we create complete business solutions and end-to-end services that supportyou throughout your projects. We have delivered large-scale digital transformation projects both in-house and for our customers. Ouroffer is modular, so we can give you the features that you need, with either 100% Orange products or incorporating joint products fromother suppliers.Orange, SA – Corporation with share capital of 10,640,226,396 euros – 78 rue Olivier-de-Serres, 75015 Paris – RCS Paris 380129 866 – non contractual document – December 2016 – Photo credits: Orange 2016 - Indexel
by IBM, it is now available in open source. This protocol is well suited to M2M appli-cations that require frequently sharing small messages (thanks to a very low overhead ratio per message). Many MQTT applica-tions and libraries are available. AMQP (Advanced Message Queuing Protocol) is an open protocol created to share messages between servers.
