Nº 6 2013 > Radio-frequency spectrum
What will be left for the next generation?
Advances in radiocommunication and spectrum management have led to tipping points in technology, for example the invention of the semiconductor and microprocessor, the shift to a digital, converged, personalized, broadband world, and now the advent of spectrum cognition in radio devices.
At the same time, regulatory activities are evolving from a centrally planned, regulated and market-driven approach to what may become an open radio environment. During this period, we have seen radio moving from utility-based to technology-based devices, and wireless evolving from an exclusive technology to become a core function embedded in every device and available in almost every home.
For these trends to progress for the benefit of users, we need to take wise and timely decisions on spectrum policy and management. These decisions will be taken in the common interests of all, not just to offer advantages to a few countries. That is where ITU will continue to play a vital role for the benefit of humanity as a whole.
A memorandum by the President of the United States, published in June 2013, recognizes that expanding the availability of spectrum for innovative and flexible commercial uses, including for broadband services, will further promote economic development by providing citizens and businesses with greater speed and availability of coverage, encourage further development of cutting-edge wireless technologies, applications and services, and help reduce usage charges for households and businesses. Similarly, the Digital Agenda for Europe acknowledges that radio spectrum is an essential natural resource for wireless connections and innovation.
All this puts ITU in the spotlight, and particularly its Radiocommunication Bureau, which must fulfil the task of ensuring “the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services,” according to the ITU Constitution.
Regulations that respond to needs
Appropriate frameworks for regulating spectrum on the national, regional and global levels are essential to make spectrum available on a timely basis and its use as efficient as possible.
The WRC process is the mechanism by which ITU Member States update the Radio Regulations, the international treaty governing frequency spectrum and satellite orbit use. These global conferences are convened every three to four years and may be attended by as many as 3000 delegates from the 193 ITU Member States, who meet over a period of four weeks to discuss more than 2000 legally and technically complex proposals to update the treaty.
In preparation for these global conferences, government and industry experts adopt reports that provide the technical bases for WRC debates. These reports comprise mainly the results of studies on the possibility of sharing spectrum among the various radio services concerned. For more than a century, this process has proven to be responsive to the accelerating growth in radio spectrum needs, emanating from the increasing demand for innovative wireless services and applications.
Some examples show how the ITU process of spectrum allocation has responded to government and industry needs, fostering innovation. World radiocommunication conferences (WRCs) have taken many forward-looking decisions, for instance in 1992 on global mobile personal communication systems better known as GMPCS (such as Iridium) and IMT-2000 (3G) spectrum allocations, in 2000 on global navigation satellite systems (such as Galileo), in 2003 on Wi-Fi (for example, 802.11a in the 5 GHz band), in 2007 on IMT (concerning 3G additional spectrum and 4G), and in 2012 on the second digital dividend (notably 4G in the 700 MHz band).
Today, the Radio Regulations — a book of some 2000 pages — govern the use of more than 40 radio services and cover the whole of the usable radio spectrum, from the extremely low frequencies used for lightening detection to the extremely high ones used for scientific passive observations. These complex regulations have evolved from the International Radiotelegraph Convention of 1906, a 20-page document regulating only the international maritime service.
Harmony or discord — take your pick
One of ITU’s major objectives in considering the allocation of spectrum to different radio services is to seek harmonized solutions on a global or regional basis. Spectrum harmonization reduces the cost of mobile hardware (for example, leading to cheaper smartphones) and the cost of infrastructure, enables global roaming, decreases the complexity of radio design, reduces interference with adjacent services, and helps in managing cross-border interference.
Despite these advantages, mobile spectrum allocations are not harmonized throughout the world as a consequence of uncoordinated national regulatory decisions on the use of the new 3G/4G bands allocated by WRC‑07 and the legacy allocations of 2G spectrum bands. Examples of the lack of spectrum harmonization are the North America frequency plan for 700 MHz, and the use of CDMA in 850 MHz and GSM in 900 MHz.
ITU, in coordination with regional groups, is working towards promoting harmonization of the mobile broadband spectrum, particularly in the frequency bands freed up by the transition from analogue to digital terrestrial broadcasting (the digital dividend).
We have come a long way since the early days of telegraphy, when telegraph lines did not cross national borders and when each country used a different system, so messages had to be transcribed, translated and handed over at frontiers, to be retransmitted over the telegraph network of the neighbouring country. But there is still a way to go.
Dynamic shared access to spectrum
Some spectrum management techniques depart from the traditional command-and-control mechanisms used for most of the frequency bands, and have also driven innovation.
Wireless access networks such as Wi-Fi, for example, have developed within unlicensed spectrum, shared on a commons approach on the basis of “best effort”. A plethora of wireless technologies to provide short-distance wireless access to devices, including personal appliances, have been or are being developed within the spectrum bands identified for unlicensed use. These include technologies that are expected to create the next wave of the wireless revolution — known as the Internet of things, because they concern mainly machine-to-machine connections or simply large numbers of objects to be connected.
Today, connected humans are already in the minority of Internet “users”. According to an estimate made in 2010 by Ericsson, there will be more than 50 billion connected devices by 2020, outnumbering connected people by a ratio of perhaps ten to one, and transforming our concept of the Internet forever.
Creative ideas are being studied or implemented to provide effective regulatory responses to deal with the growing and urgent spectrum requirements of services and applications. One such idea is the concept of authorized shared access, whereby dynamic use of the spectrum is made whenever and wherever frequencies are unused by incumbents. This sharing takes place on a non-interference basis, subject to individual authorization (in other words a licence), in bands allocated to the mobile service (and identified for IMT) by ITU. The techniques deployed to enable this sharing of bands are within the general concept of cognitive radio — geolocation databases complemented, if required, by sensing.
A derivative of these ideas concerns the use of idle spectrum in the bands assigned to video broadcasting, known as television white spaces. In this case, the opportunistic use is normally on a licence-exempt basis. This approach is currently getting the attention of the most important players in the Internet industry. In June 2013, a group of 23 organizations from around the world formed the Dynamic Spectrum Alliance to promote improved spectrum management and help develop new wireless technologies.
From spectrum identification to commercial deployment
One enlightening example of the relationship between spectrum and innovation is related to 3G mobile communications — known to ITU and the industry as IMT-2000. In 1986, ITU set up a group of experts to discuss the concept and requirements for a future land mobile telecommunication system based on personal cellular phones to be used on a worldwide basis. Mobile phones weighed 1.3 kg and were sold at a cost of USD 4000 each. By 1992, ITU visionaries had been able to define the system design and identify the needed spectrum. At that time, the first GSM networks — 2G — were being rolled out in Europe, thanks to the establishment 13 years earlier, in 1979, of spectrum for GSM.
The timespan from spectrum definition to commercial deployment was reduced to eight years for 3G, if the 3G system launched in Japan in October 2000 is considered to be the first. This delay was reduced to three or four years for the 4G systems being deployed in the digital dividend spectrum and for future generation mobile systems that will be deployed in spectrum that is in the course of being earmarked today.
The identification of additional spectrum with particular physical properties has given rise to the advent of, on the one hand, broader coverage with fewer base stations (VHF/UHF of the digital dividend), and on the other hand, higher capacity wireless systems of the IMT family, which are becoming an effective way to provide the greater part of the world’s population with broadband access to the Internet.
More than 150 years ago, when the electric telegraph was invented, an Australian newspaper commented that “anything more perfect than this is scarcely conceivable, and we really begin to wonder what will be left for the next generation, upon which to expend the restless energies of the human mind.”
Incredible progress has been made since then, and more is certain to come. The directions defined by spectrum management decisions will pave the way and dictate the pace of wireless innovation.
This article is adapted from a speech delivered by Fabio Leite at the Spectrum and Innovation Conference organized by France’s National Frequency Agency, Agence Nationale des Fréquences (ANFR), in Paris, on 26–27 June 2013.