2. 1. Introduction
Machine-2-Machine (M2M) connectivity
technologies aim to enable remotely sensing,
monitoring, and controlling devices by
allowing diverse (real and virtual) objects to
communicate with each other without the
need of human intervention. In addition to
routing data between objects, M2M gives
the possibility to organize, trace exchanges,
manage communicating objects and
minimize related communication costs.
M2M, Machine Type Communication (MTC),
or Internet of Things (IoT) is one of the basic
pillars of the Future Internet, beside the
Internet of Content (IoC), and Internet of
Services (IoS), enabling seamless Smart City
communications and applications.
Although the concept behind the M2M
communications is not completely new,
Supervisory, Control and Data Acquisition
(SCADA) systems have been utilized in
control and manufacturing industries since
the 1970s. However, it is predicted that in
the next decade the M2M market will
witness accelerated growth. The forecasts
regarding revenue or number of future
M2M-connections may vary, but it is
expected that there will be more machines
Table of Content
1. Introduction
1
2. M2M Platform Technical Requirement
3
2.1. Standardization
4
3. The OpenMTC Platform
5
3.1. Client/Server RESTful Architecture
5
3.2. Standard End-to-End M2M Solution
6
3.3. Associated Software Development Kit (SDK)
7
3.4. Interworking with telecommunication Cores
7
4. Reference Use Cases
8
5. Summary
10
1
3. connected to the Internet than human
beings. Machina Research estimates that by
2020 there will be 12 billion M2M
connections globally, up from 2 billion in
2011, and 1.6 billion devices will be
connected to fixed broadband in 2020 [1].
Due to Machina Research Utilities,
Automotive and Healthcare will be the most
significant ‘industry’ verticals, as illustrated
in Fig. 1.
The motivation of this new trend in
operator networking is two-fold: technical
and economic. On one hand the advancement of semiconductor industry shrinking lithography continues to reduce chipset
cost and power consumption, and embeds
more sensors into devices used in different
aspects in our daily life. On the other hand
the technology evolution in Internet and
advanced wireless networks make it possible
to provide broadband data service at a
significantly lower cost per bit transferred
Figure 1. M2M connections by sectors, 2020
[Source: Machina Research 2011]
than in the past. In addition recently the
mobile market becomes saturated and highly
competitive, which raises the need to
introduce new potential services to fill the
revenue gap. For mobile operators alone,
ABI Research, a technology market research
firm, estimates annual revenue in 2016 of
US$35bn
(€26bn),
with
automotive
accounting for the biggest single sector [2].
2
4. 2. M2M Platform Technical Requirement
A new platform is needed to suffice the
requirement of the new communication
paradigm that will be coming from largescale M2M communication scenarios.
Previous network architectures (e.g., IP
Multimedia Subsystem (IMS)) were built to
be connection-oriented, suitable to support
Human-to-Human (H2H) and Human-toMachine (H2M) communications. However,
M2M presumes the independent communication between a large number of
devices, sensors and actuators – and service
platforms, which in turn presumes the
transmission of large amount of data of
heterogeneous types and sizes over the
network. For instance some M2M devices
will have restricted processing, memory and
transceiver resources. And they will be
placed in less accessible or critical locations.
collection while having a sensor-level
granularity and actuation of specific sensors
in specific network locations. Therefore it is
important to optimize the usage of the M2M
platform interfaces in order to address
interoperability and scalability issues and
facilitating the harmonization of services into
interoperable services, eventually forming
the Internet of Services (IoS).
b) Data Processing
The general requirements in the design
and implementation of M2M systems, which
are tailored to machines rather than human,
can by summarize in the following:
M2M platforms share many of the key
challenges similar to large scale data
initiatives, in terms of handling the data
streams aggregated from billions of devices,
and make them usable by various
applications. As huge amounts of data and
information are provided to the system,
methods need to be involved in
understanding, combination, and processing
the content aggregated from different
sources and in different formats in order to
address the Internet of Content (IoC)
challenges.
a) Optimal Network Design
c) Security and Privacy
The main goal of M2M platforms is to
connect efficiently a great number of devices
and associate them to a set of services. One
main factor influencing the connectivity of
the devices to services is related to the
operational costs. It is assumed that M2M
data traffic is different from the one of
human-based communication due to the
specialized functions involved e.g., large data
Most M2M applications are influenced
to the robustness and security of the
communications such as eHealth or SmartGrid. Therefore, an M2M platform has to be
secured directly from the design. The
communication of the devices and the
network core should be secured against a
large variety of security threats. A major role
in securing the communication between
3
5. machines/devises is held by the network
providers which are able to notify the M2M
platforms on the availability of the device in
the network, on its reachability parameters
as well as on the security credentials for
secure data exchanging.
d) Governance
M2M applications involve many
different stakeholders, such as distinct
application providers, devices vendors, radio
and core network providers. In order to be
able to manage consistently the overall
system, flexible horizontal solutions are
needed for sharing skills, network
infrastructures and devices between
stakeholders. Through this horizontal
middleware proper governance can be
realized avoiding the mishandling of
sensitive data and unsuitable access grants.
2.1. Standardization
functional architecture for Machine Type
Communications (MTC).
The Open Mobile Alliance (OMA) [5]
specifies the Lightweight M2M Protocol
for limited capability devices.
ZigBee Alliance [6], a suite of high level
communication protocols using small
and low-power digital radios.
Telecommunications Industry Association (TIA) [7] established the TR-50.1
Smart Device Communications Engineering Committee, aiming to develop
an M2M Communications framework
that can operate over different
underlying transport networks.
oneM2M, a consortium of several
standards development bodies to
reduce the standardisation overlap by
providing ongoing standards support,
and increase the ability of M2M
solutions and produces to interoperate
[8].
Recognizing the need for reliable
network infrastructures and the associated
challenges, various standards developing
organizations (SDO) have recently promoted
several standardization activities in the M2M
communication domain, just to mention a
few:
European Telecommunications Standards Institute (ETSI) TC M2M [3] mainly
focusing on the service middleware
layer.
The 3rd Generation Partnership Project
(3GPP) [4] address requirements and
4
6. 3. The OpenMTC Platform
The OpenMTC platform is a prototype
implementation of an M2M middleware
aiming to provide a standard compliant
platform for Smart City and M2M services. It
has been designed to act as a horizontal
convergence layer supporting multiple
vertical application domains, such as
transport and logistics, utilities, automotive,
eHealth, etc., which may be deployed
independently or as part of a common
platform. OpenMTC features are aligned
with ETSI M2M Rel. 1 specifications.
OpenMTC mainly consist of two service
capability layers, a gateway service capability
layer (GSCL) and a network service capability
layer (NSCL). Those have been defined and
specified by the ETSI Technical Committee
M2M in [9] and [10]. Following ETSI
capabilities are supported in OpenMTC:
Generic Communication (xGC)
Application Enablement (xAE)
Reachability, Addressing and Repository
(xRAR)
Remote Entity Management (xREM)
Interworking Proxy (xIP)
Security Capability (SEC)
Network Communication Selection (NCS)
Network Telco Operator Exposure
(NTOE)
Figure 3 depicts the OpenMTC architecture,
showing supported capabilities in GSCL and
NSCL and possible interworking with other
telecommunication cores. OpenMTC is a
cooperative development of Fraunhofer
FOKUS and Technische Universität Berlin
(TUB).
3.1.
Client/Server
Architecture
RESTful
OpenMTC supports a client/server based
RESTful architecture with a hierarchical
resource tree defined by ETSI. This style
governs how M2M Applications (xA) and
gateway and network capability layers (xSCL)
are exchanging information and data with
each other. Each entity in the M2M system
(application, gateway, or device) is presented by uniquely addressable resource in
the hierarchical tree, which can be accessed
and manipulated by CRUD verbs (i.e. Create,
Retrieve, Update and Delete) over different
stateless transport protocols (e.g., HTTP).
Adopting the RESTful style facilitates the
development of M2M applications, due to its
simplicity in comparison with most serviceoriented architecture (SOA) technologies.
5
7. 3.2. Standard End-to-End M2M
Solution
ETSI specifications define three interfaces:
mIa, dIa and mId, as depicted in Fig. 2, which
offer generic and extendable mechanism for
interactions with the xSCL. The mIa interface
mediates
the
interactions
between
applications in the application domain (NA)
and the Network SCL (NSCL), the dIa
interface mediate the interactions between
applications in the M2M network area -
Figure 2. OpenMTC Architecture
6
8. being Gateway applications (GA) or Device
Applications (DA) – and the gateway SCL, and
the mId interface mediate interactions
between xSCL. Communication over all
interfaces is independent of the transport
protocol. HTTP is commonly used as
transport protocol with RESTful-based
services, CRUD operations are mapped to
HTTP methods POST, GET, PUT and DELETE.
However, M2M devices are generally
resource-constrained devices, i.e. they are
limited in memory, energy and computation
power. Therefore HTTP is most likely difficult
to implement in them, and many protocols
have been standardized to incorporate such
devices into the Internet. The Constrained
Application Protocol (CoAP) is emerging to
support essential features required for
constrained M2M devices, such as low
header overhead. Currently only HTTP is
supported as a transport protocol in
OpenMTC platform.
3.3.
Associated
Software
Development Kit (SDK)
To support the development of innovative M2M applications easily and quickly,
the OpenMTC toolkit provides a Software
Development Kit (SDK) to make the core
assets and service capabilities available to
3rd party developers. The OpenMTC SDK
provides M2M applications with standard
interfaces toward the OpenMTC that
consists of different service capabilities
meant to support interactions between
machines, for example sending data
gathered from sensors to web servers and
executing actions according to specific
criteria. The OpenMTC SDK consist a set of
high-level abstraction Application Programming Interfaces (APIs) which hide internal
system details, and allow the developer to
concentrate in the implementing logic. The
mIa Interface of the OpenMTC is exposed to
the
FOKUS
Broker
[11]
allowing
telecommunication and Internet services
composition with M2M services, facilitating
Smart Application development for Smart
City.
3.4.
Interworking
telecommunication Cores
with
OpenMTC
capabilities
support
interworking with other telecommunication
cores, such as the IP Multimedia Subsystem
(IMS) and Evolved Packet Core (EPC).
Translating the information exchanged from
sensors and devices into Session Initiation
Protocol (SIP) messages enables the usage of
IMS for various M2M applications. Through
this means, the M2M communication can
rely on the security and reliability of IMS.
EPC
provides
advanced
networking
capabilities, such as policy and charging
control, OpenMTC relay on the OpenEPC [12]
for connectivity selection management and
carrier grade Quality of Service (QoS).
7
9. 4. Reference Use Cases
The OpenMTC platform can be applied to
any use case as an enabler to a Smart City
system. Following references use cases are
implemented to demonstrate the OpenMTC
capabilities:
a) Smart Home
Making our environment smart is one of
the popular M2M applications. With Smart
Home applications the user gets the
possibility to configure the system for
various purposes, such as home automation,
security, and control energy consumption.
Fig. 3 shows screenshots of client
applications used for the demo. In a control
energy consumption scenario, the user will
get notifications about still switched-on
devices as soon as he exits a certain userdefined radius from home, and the user
client application presents a list of supported
actions, e.g. switch off one or more devices.
Interested readers are referred to [13] for
full description of this demonstration.
Fig 3. SmartHome client screenshots: IMS client (left) and Android application (right)
8
10. b) Location Rating
Point-of-Sale (POS) marketing is kind of
Location-aware services, used to attract
retail shoppers at the point of a purchase. In
addition to the user/device profile; which
provides information for the service delivery,
the location specific aspects (popularity, etc.)
can be used to enhance the service/
application experience. In this user case, the
OpenMTC platform will use the location of
specific resources in order create a rating for
a specific area. Gateways (GSCLs) equipped
with technologies like Bluetooth or 802.11,
collect and store the sensors data in
containers, in addition to location infor-
mation of themselves. The containers are
published in the NSCL M2M resource tree
(through announcements). Through the mIa
interface network applications (NA) get
access to this information and derive
answers to questions similar to: How many
people are in the area XYZ? How many
people visit the area XYZ between 10:0014:00? Fig. 4 shows a screenshot of a demo
application display the disruption of wifi
vendors in a specific location.
Figure 4. Location rating screenshot
9
11. 5. Summary
M2M technologies can be beneficially
applied to a broad range of applications and
services in Smart Cities, by creating a scalable IPbased environment where machines can
communicate with each other without human
intervention. Currently, service providers are
building new eco-systems with partner vendors
to offer new innovative services for M2M and
Smart Cities. Standards like ETSI TC M2M can
help in accelerating the development of globally
accepted solutions for M2M. In this paper, we
present the OpenMTC Platform, which aims to
provide a standard-oriented middleware
platform for M2M applications and services,
enabling research and development of M2M
systems. OpenMTC helps to be prepared for the
upcoming all-IP NGN and M2M world using an
open and vendor independent testbed
infrastructure.
10
12. Reference
[1] Machina Research, “Connected Intelligence Database”, October2011.
[2] ABI research, “Maximizing Mobile Operator Opportunities in M2M - The Benefits
of an M2M-Optimized Network”, 2010
[3] ETSI –M2M [online] http://www.etsi.org/website/technologies/m2m.aspx
[4] 3GPP, “System Improvements for Machine-Type Communications,” TR 23.888
V0.5.1., July 2010
[5] OMA - Open Mobile Alliance [online] http://www.openmobilealliance.org/
[6] Zigbee [online] http://www.zigbee.org/
[7] Telecommunications Industry Association [online]
http://www.tiaonline.org/tags/m2m
[8] OneM2M [online] http://www.onem2m.org/
[9] ETSI TS 102.690, “Machine-to-Machine communications (M2M); Functional
architecture,” December 2011.
[10] ETSI TS 102.921 V1.1.1, “Machine-to-Machine communications (M2M); mIa, dIa
and mId interfaces“, February 2012
[11] FOKUS Broker - Policy-based Service Access, Orchestration and Composition
[online]
http://www.fokus.fraunhofer.de/en/fokus_testbeds/open_soa_telco_playground
/software/fokus_broker/index.html
[12] OpenEPC - Open Evolved Packet Core [online] http://www.openepc.net/
[13] Wahle, S.; Magedanz, T.; Schulze, F.; , "The OpenMTC framework — M2M
solutions for smart cities and the internet of things," 2012 IEEE International
Symposium on a World of Wireless, Mobile and Multimedia Networks
(WoWMoM) , pp.1-3, 25-28 June 2012, doi: 10.1109/WoWMoM.2012.6263737
11
13. List of Acronyms Related to M2M
3GPP
AE
API
CN
CoAP
EPC
GC
GIP
HTTP
IMS
IoC
IoS
IoT
JSON
M2M
MIME
MTC
NGN
QoS
RAR
REM
REST
RTC
SCL
SDK
SOA
SOAP
WoT
XML
Third Generation Partnership Project
Application Enablement
Application Programming Interface
Core Network
Constrained Application Protocol
Evolved Packet Core
Generic Communication
Gateway Interworking Proxy
HyperText Transfer Protocol
IP Multimedia Subsystem
Internet of Content
Internet of Services
Internet of Things
JavaScript Object Notation
Machine-to-Machine
Multipurpose Internet Mail Extensions
Machine Type Communication
Next Generation Network
Quality of Service
Reachability, Addressing and Repository
Remote Entity Management
Representational State Transfer
Real-Time Communications
Service Capability Layer
Software Development Kit
Service-Oriented Architecture
Simple Object Access Protocol
Web of Things
eXtensible Markup Language
12
14. Contact
More information about
OpenMTC can be found at:
www.open-mtc.org
Contact the experts at:
info@open-mtc.org
Fraunhofer Institute for
Open Communication
Systems FOKUS
Kaiserin-Augusta-Allee 31
10589 Berlin, Germany
www.fokus.fraunhofer.de
