Why do machines need telephone numbers?

You may have heard talk about ideas such as the 'intelligent refrigerator': it would know when you had nearly used all the milk and order some more over the internet for delivery. That is probably a rather self-indulgent example of how an increasingly interconnected world could look. And it is unhelpful, as it distracts from the many real applications now in the market or advancing that way, to bring more useful benefits to people through 'machine-to-machine communications' (M2M). But what is M2M?

'M2M' refers to technologies that allow both wireless and wired systems to communicate with other devices. Typically a device such as a sensor or meter will capture an event (such as temperature, inventory level, etc.), which is relayed through a network (wireless, wired or hybrid) to an application that translates the captured event into meaningful information. And key to enabling this is the use of public networks, or large private ones, where, just as with a phone call or logging on to a website, one machine needs to tell the network exactly what other machine it wants to communicate with.

In recent years a rapid development of a variety of services that make use of M2M communication has taken place. M2M is a communication technology where data can be transferred in an automated way with little or no human interaction between devices and applications.

The advantages of M2M are great for both business and consumers. For business use, M2M technology may lead to more effective and efficient operations (e.g. fleet control, navigation, stock control etc.). For consumers, as an example, applications used for home security, smart metering and health care assistance can be facilitated by M2M.

The prospects for this technology are also considerable. According to Berg Insight the number of cellular M2M connections worldwide is forecasted to grow at a compound annual growth rate of 32 per cent to reach around 290 million in 2015. These figures don't take into account the predicted mass scale deployment of M2M-applications mandated by governments via legislation, such as toll roads, or smart metering (see e.g. EU directive on smart meters). So this is clearly a market with a potential of 1 billion (109) connected devices worldwide in 2020!

In many European countries the existing numbering plans
can't accommodate the mass deployment of M2M-applications

While M2M is in its earlier stages of development, a logical approach by operators and M2M Service Providers is to use E.164- numbers (the international numbering scheme agreed by the International Telecommunications Union) from the existing mobile numbering ranges. This offers relatively simple implementation in the already existing network infrastructure. But the potential number of M2M devices will be large and some applications may need several numbers. Correspondingly there is a potential need for a large amount of identifiers.

After a statistical analysis conducted by the ECC's Working Group on Numbering and Networks (WG NaN), it was concluded that a new numbering strategy is required for both the short and long-term to meet the potential demand.

As a result of a lot of study and interactions with the main actors in the M2M business the WG NaN produced an expert report in 2009 on M2M-numbering which addresses the basic M2M characteristics, different access methods from M2M devices to networks and numbering and addressing alternatives for M2M applications. Finally, a set of recommendations for the National Regulatory Authorities regarding M2M numbering were proposed with four options:

  • Option A: The use of the existing mobile number ranges, including possible expansion of them (E.164 numbers);
  • Option B: A new number range for M2M or similar applications (E.164 numbers - for example longer numbers than normal but with a maximum of 15 digits according to ITU-T Recommendation E.164);
  • Option C: An international numbering solution (E.164 numbers);
  • Option D: Network internal numbers. 


The sector confirmed the initial view of the WG NaN
that IPv4/IPv6 is not an option in the short to medium term
for M2M-numbering

WG NaN's analyses were very well received by industry in the subsequent consultation. This again confirmed that in the short term IPv4/IPv6 for identification of M2M devices was not an option for the operators and service providers. It also concluded that Option A was not suitable in cases where there is a need to distinguish M2M services and the traditional mobile services. Options B or D are needed if there is no adequate space in existing number ranges in use. There are many situations where a new number range (option B) should be opened: the number range in question may require different regulatory treatment, e.g. relating to access to emergency services, or the services to be provided have certain characteristics (e.g. M2M applications in fixed networks) where existing mobile number ranges may not be adequate or there is simply not enough numbering capacity available.

In practice we see that many countries follow these recommendations. Examples are Denmark, Norway, Netherlands, Spain, Finland, Luxembourg, Sweden and Belgium who opened a new long numbering range only for M2M. In many other countries the decision is pending.

Is the work of the WG NaN finished on M2M? The answer is clearly no! In the first instance the WG NaN will further refine the results of the report and publish a recommendation for the CEPT countries on how to approach M2M-numbering in much more detail. No specific need was detected for a harmonised approach amongst the CEPT countries, but it was felt necessary to continue the momentum to put in place effective and efficient numbering solutions taking into account the specificities of the national numbering plans. Although much of the ECC's work is directed towards harmonisation we understand well that it is not always the best option, and should only be applied where it brings a clear benefit; enabling services, improving efficiency and/or bringing economies of scale.

Empowerment of M2M-users

Furthermore, M2M applications will be embedded in mobile devices with SIM-cards spread all over the world. We have for a long time had number portability in place, which makes it easier for end-users to switch from one operator to another for voice telephony, but today the SIM-cards still have to be physically replaced! For mobile devices spread out all over the world, this will be very difficult and expensive. In some case (e.g. sensors) it would even be a challenge to find where they are because the associated mobile devices will often be hidden!

In this context, the flexible use of E.212 identifiers (i.e. Mobile network codes) is one of the options to empower the user (e.g. M2M service/application provider or large company) for a more flexible choice of his mobile operator. But there are many open questions in this context and it is not assured if this will be a practicable approach. One challenge is that the rules governing E.212 resources (IMSI) have to be changed by the International Telecommunications Union (ITU). Another option is the usage of Soft SIM-cards, but operators are very reluctant to introduce that kind of technology which is still under development. Soft SIM technology allows SIM card configuration in a device over the air, i.e. the SIM card is just a piece of software.

This is only one of the challenges for 2012 for the Project Team on Future Numbering Issues (PT FNI) within the WG NaN. We always welcome further engagement with all stakeholders in the M2M business in order to find the most optimum solutions for a prosperous development of M2M.

Jan Vannieuwenhuyse
Chairman of the ECC's Working Group on
Numbering and Networks (WG NaN)

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