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MTC: When Machines Communicate (A New Hot Topic Taking Over the Industry) - also available in Spanish


Machine Type Communications (MTC)

Recently the wireless industry has had an increasing interest on M2M (Machine to Machine) communications linked to technologies like Smart Grid, Wireless Sensor Networks, and applications focused on maximizing the control of resources and tracking of goods. But exactly what benefits does M2M bring to the industry, how is the market embracing it? And more importantly, why so much hype? My first approach to the technology led me to think that it wasn’t too relevant for the industry and I quite didn’t see a true impact for the wireless user but, this opinion changed when I got better informed and went a bit deep on the concept. In this post I share my views on the technology; how it all started, why I think it became relevant and my conclusions on why the industry must be excited about it.

Origins and Related Concepts  

The communication between machines, objects, etc. is older than the modern concepts of wireless networks; in fact the mass adoption of computing and the evolution of networking favored the concept of the Internet of Things to spur. In its early days the concept was centered on providing objects with unique ID’s and radiofrequency capabilities to allow certain industry requirements like tracking and inventory control to be fulfilled without the need of humans, so commercialized solutions for RFID has been known ever since. Today the concept is a bit different, and its goal is to allow objects and things to produce massive amounts of information, as today, such information is produced only by humans.

In the wireless environment the first approach to M2M was presented by research groups from device manufacturers that came with the concept of making communication modules with all the circuitry needed to attach to cellular networks but without the regular human interface. These modules could be included in almost any device the user could think of; in consequence the device will inherit the communication capabilities of the module. So the first applications emerged in the mid 90’s for the automotive industry, points of sale, fulfilling requirements of tracking and monitoring. So we have had M2M communications for some time, but it has to be considered that by no means this early applications became a major source of revenue for MNO nor had the potential to cause an impact on the market, so what’s different now?

Pushing to Become Relevant

The major difference between now and then is of course the performance of wireless networks when the first M2M applications appeared, the cellular wireless networks had just started to optimize their second generation architectures for data traffic (i.e. EDGE for 2G GSM); on the other hand there were no features to develop flexible solutions. Only by 2005, Java features started to be added to the modules and the manufacturing became specialized for different environments. All these and other advances paved the way and by the end of the first decade of the 2000’s, the first MNOs made public statements supporting the development of the technology.

But again the technology kept a low profile, something was missing, and that something happened at the beginning of 2008 when the first true virtual environment built around the concept of a smartphone exploded. Now we have virtual stores to access applications that allow users to make their smartphones a customized tool. The path for MTC protagonist role was set.

Functional Architecture of MTC

The industry and academia are putting together standards and technical descriptions to optimize the wireless network for MTC. To describe the functional architecture of this technology we can split it into three domains:

  • Device domain: containing all possible machines, objects and other end user devices intended to communicate.
  • Communication network domain: is the backbone structure that provides access to the Device domain, provides subscription control, Security and interworking with the Application domain.
  • Application domain: Containing virtual stores, virtualized environments, and management solutions for MTC.

The devices can communicate in different ways; directly to each other or D2D (device to device), or using the network assistance to establish communication and finally between the application server and the device. In addition to providing assistance to the communication, the network must provide all the necessary means to allow the management of subscription to the service to a large group of devices; providing at the same time control mechanisms and user interfaces to interact with functional entities like HLR, HSS and databases fundamental for the service, all while maintaining the levels of QoS for H2H (Human to Human) communication.

In order to provide a compatible environment for H2H and D2D communications, the industry and academia are making an effort to define and categorize all MTC solutions using differencing traits of their communication with the network or the application server; these categorizations are called network features and so far the following have been defined: Low Mobility, Time controlled, Time tolerant, PS only, Small data transmissions, MO only, MTC monitoring, Priority alarm, Secure connection, Location specific trigger, Network provided destination for Uplink data, Infrequent transmission, Group based MTC features.

Deep Quick Look on the Network

Additional functional entities have also been proposed at the network to enable an optimized use of the resources without causing an impact on regular human communications. The first entity is called the MTCG (MTC Gateway): an optional functional entity capable of providing centralized access and power control for devices without proper MTC features and capabilities; it is located between the Device domain and the Network domain. SCS (Service Capability Server) is an intermediate network element between the network and the Application domain and provides APIs (tools for programmers to use Telecom network specific features in their applications). MTC-IWF (MTC Interworking Function) is located internally in the Network domain and its function is to centralize the communication of various devices per characterized features towards key network functional entities providing, Authentication, Authorization, Accounting and management of subscription.

Technology Challenges


Next I’ll list the main obstacles the industry and academia are trying to address:

  1. Increase in co-channel and inter-channel interference: Industry proposes enhanced interference schemes already proposed in Rel-11 for LTE-A and future improvements for Rel-12.
  2. Node discovery (before communication can happen nodes need to be identified and found): Industry proposes Network aided schemes to speed discovery between nodes making it seamless for the user.
  3. Signaling congestion and network overload: Industry proposes different traffic controls on the RAN and NAS sections of the network all combined with aggrupation of devices per features, and geographic zones where one functional entity decides to grant or not access to a particular group of devices, plus sophisticated spectrum allocation schemes focused on avoiding signaling congestion.
  4. Non transparent LTE global roaming: Industry works in several countries to harmonize LTE spectrum bands.

Looking Ahead

In the middle of all the enthusiasm, one very powerful concept emerged as a solution to millions of people that do not have access to basic services but do have a mobile phone. The idea is to allow the distribution of remote facilities to provide fundamental services using smartphone balance account and MTC without the need of a costly centralized government or private facility. Another field is BSN (Body sensor networks): these were conceived as collections of sensors distributed throughout the body that gather vital signals information and then sending it to an application server in the Internet. MTC will finally provide a functional framework to make it possible. Lastly, and as I commented on the introduction, machines are to be given the task to produce information. If so, the amount produced can surpass by a great deal the amount produced today. Big Data is the name that IT industry uses to group the mathematical algorithms, virtual spaces and in general all the solutions that allow the collection, organization, management and interface for the vast amount of data that MTC and other technologies enable. Applications and OTT (over the top players: like big Internet companies) environments will also play a big role, I’ll share next my opinion on how these will be relevant for MTC and the wireless industry.

The Applications Environment and Its Influence on MTC

The Wireless industry realized quickly the importance of applications and Internet specialized ecosystems for MTC technology, so by the end of 2009 MNO started to call out developers interested in MTC to present its proposal on apps and solutions, awarding them with money and other stimulus. This has evolved today to a complex offering of specialized developer platforms sponsored by many stakeholders of the industry. Such platforms are capable of supporting the application from the creation till the maintenance after release. Specifically speaking of the applications it can be said that they can be categorized under two big groups: the classic client server model and the D2D (P2P) model. Within these two groups each app provides solutions for any of the following communication specific requirements:

  • Elastic applications (i.e. FTP, email)
  • Hard real time applications (i.e. voice)
  • Delay adaptive applications (i.e. audio and video)
  • Rate adaptive applications (i.e. adaptive streaming)

Today, the industry continues to promote yearly challenges inviting entrepreneurs and developers in search for innovative solutions. Several early providers now have online platforms including Cloud capabilities and management tools that allow developers to not only build the application but to manage the data produced by the machines that compose the solution, also allowing them to control aspects of the cellular subscription of the devices. In other words, these platforms are interfacing with the cellular network as it has been proposed by the current standards. Application Domain of MTC has come up with its own architecture composed of Application Enablement Platforms (AEP) which interfaces with the network to manage data produced by machines and allow integration to cellular networks. Application Development Platforms (ADP) provides the tools to the developer to build SW aspects of his solution.

The Circle is Complete: MTC and the MNO - OTT struggle

MTC is founded on the premise that devices interact to produce data without human assistance, but that data has to be put at the service of humans The only known way to do that is by means of user interfaces and mechanisms that allow an easy query, or in general terms, an intuitive experience and interaction. Since computing usage habits are migrating from static to mobile, the inductive thinking process leads to conclude that OTT ecosystems (Mobile Operating systems, Application stores, etc.) are the most effective channel to provide humans with such interfaces; as well the virtual environments and the control over the vast amounts of information to be produced by machines Why? Well mainly because almost everyone with a smartphone is familiar with the concept of applications. In terms of management, trends like BYOD and tools like the virtual stores could ease the distribution and version control of the interface and other aspects, allowing companies to also address security concerns in some way. So in conclusion, my opinion is that OTT ecosystems are helping MTC to become relevant.

MTC was born from a MNO perspective. The operators are the ones pushing for this trend to explode and the fact that OTT ecosystems are helping to make it relevant provide the irony ingredient for all the media articles produced around the subject. MTC is by no means an exclusive market many stakeholders from diverse fields are already involved and I think is a chance for MNO to prove their capacity to be innovative and flexible in an ever changing market.

Final Thoughts

The existence of commercial solutions for M2M is real, but it is also real that these solutions are deployed on non-optimized for the purpose cellular networks and in the likely scenario of massive MTC adoption this optimization will be needed in order to avoid interference with regular human communications. Early commercial solutions are a fundamental to identify real needs on the market, to build an initial relationship with the customer of the technology and to create commercial bonds that will nourish the ecosystem. Current solutions like portable card payment terminals, transportation metering, smart grid, security through tracking, among others will benefit from an optimized environment integrated with OTT ecosystems and other wireless technologies.

My personal opinions on some of the benefits of MTC are:

  • It will test the capabilities of the industry service providers as being truly innovators able to change and adapt to market dynamic requirements.
  • It could help to create interesting collaborations between OTT actors and MNO.
  • QoS (Quality of Service) schemes must grow mature and widely spread throughout networks to allow coexistence of M2M and H2H communications.
  • It will provide another testing scenario for different wireless technologies to be integrated under the purpose of the realization of a service. Standards propose that direct D2D communication be implemented through non licensed bands coordinated from the network in regular licensed spectrum bands; this opens the door for other wireless technologies to join in.

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Read this blog post in Spanish