Nº 3 2015 > Mainstreaming Innovations and Enhancing Performance Decade by Decade
History of the ITU Telecommunication Standardization Sector
Standardization has been integral to ITU since the very beginning, and was indeed part of the raison d’être for founding ITU in 1865, when representatives of twenty European States first met in Paris to coordinate and set standards for the telegraph systems in Europe (see separate article in this edition based on the ITU Talk by Dr Kars Aznavour). In their simplest form, agreed (or voluntary) standards represent a common way of doing things and can help ensure interoperability. They may also set a benchmark for quality and common knowledge, as well as a set of market norms and/or expectations of service.
The International Service Regulations or Telegraph Regulations (annexed to the International Telegraph Convention) governed operational issues for telegraphs, including tariffs. These Regulations were revised and updated by subsequent conferences to match the technological advances of the day (such as the development of telephony).
To fully exploit the power of these new and rapidly evolving technologies, governments and companies quickly realized that international cooperation was necessary. As early as 1885, ITU Member States saw the need to add the international telephone service to the Telegraph Regulations. However, it took a further forty years before the standardization process became fully formalized, with the mainstreaming of two consultative committees at the 1925 International Telegraph Conference:
- The International Telephone Consultative Committee (CCIF) to study and develop standards for terminal equipment, transmission quality and tariffs for long-distance telephony (already established in 1924, but brought into the League of Nations system in 1925); and
- The International Telegraph Consultative Committee (CCIT) to deal with the technical and operational aspects of telegraphy, to standardize phototelegraphy and to establish tariffs and international terminology.
To facilitate their work, these Committees were to operate through Study Groups to carry out research and develop proposed standards (called Recommendations) for approval at regular Standardization Conferences (later called Plenary Assemblies).
By the 1950s, telephony and telegraphy were using the same transmission channels: overhead wires, underground cables, underwater cables and radio circuits. In view of the similarity of many of the technical problems faced by the CCIF and CCIT, in 1956, a decision was taken to merge the two committees into the single International Telegraph and Telephone Consultative Committee (or CCITT, basing the acronym on the French version) to study technical, operating and tariff questions related to telegraphy and telephone and to issue recommendations on them. The CCITT was charged with examining telegraph operational and tariff matters, transmission rules, the gentex service, terminal charges in Europe, phototelegraphy, tariff problems and procedures for the international telephone service.
The 1960s saw huge advances in telecommunications, such as the development of the Improved Mobile Telephone System (IMTS, also known as 0G), an early forerunner of today’s mobile telephony systems, as well as the introduction of the first modems. In the early 1960s, the CCITT researched different aspects of intercontinental connections (such as submarine cable and evolved numbering and routing plans, all of which ITU–T is still engaged in today). This led to Recommendations such as ITU–T E.29, Numbering for international work, national and international numbering plans (ITU–T E.160) and the international routing plan (ITU–T E.171). The international telephone numbering plan defined by ITU–T has governed country codes, area codes and local numbering ever since.
The value of ITU’s work was reflected in rapid growth in ITU membership, with the number of ITU Member States growing from 96 to 129 between 1959 and 1965. The CCITT also held its first meeting (its Second Plenary Assembly) outside Europe in New Delhi, India, reflecting the vibrant, growing global interest in telecommunications. More and more nations started to participate in ITU’s work, and its Recommendations started to gain universality. The Fourth CCITT Plenary Assembly held in Mar del Plata, Argentina, in 1968, culminated in important outcome reports on the telephone network, transmission systems and automatic telephone networks, and the first-ever international standards for fax machines (used extensively by international news corporations and meteorological services).
In the late 1960s, the CCITT completed its Signalling System No. 6 (SS No. 6) specification for international circuits, a major advance in defining the signalling links for the transfer of all information and control signals between exchanges. Another key standard for data exchange in circuit switched networks was also approved in 1968 — Recommendation ITU–T X.21 on interfaces between data terminal equipment (DTE) and data communications equipment (DCE) for synchronous operation on public data networks. Meanwhile, the Defense Advanced Research Projects Agency (DARPA) of the United States started work on a little-known network called the ARPANET…
The 1970s saw a sweeping technical revolution in telecommunications, with a massive changeover to digital techniques, while the formerly separate domains of computers and communications became increasingly — and inextricably — linked. Long-distance transmission capacity exploded — via new technologies for high-capacity submarine cables and satellite techniques, while old services were upgraded using new techniques. These innovations meant that the cost of services was no longer dependent on distance, and costs fell dramatically. Many of these changes could not have been effectively realized, without the invaluable work of international standardization. CCITT’s work evolved continuously to match the changes in telecommunication technologies.
In the late 70s and the early 80s, there was important progress in standardization work on public switched data networks, new specifications on digital techniques, programming languages and digital networks. The Seventh CCITT Plenary Assembly in Geneva in 1980 endorsed ISDN (Integrated Services Digital Network) as an international communications standard for allowing voice and data to be transmitted simultaneously across the world, using end-to-end digital connectivity. Recommendation ITU–T X.25, the highly influential ITU–T standard protocol suite for packet-switched wide area networks (WAN), was also approved during this period. ITU–T approved its packet-switched Signalling System 7 (SS7) protocols to ensure that telecom systems worldwide could interoperate, and which is also important for linking VoIP (Voice over IP) traffic into PSTN (Public Switched Telephone Network).
In Melbourne, Australia, in 1988, the World Administrative Telegraph and Telephone Conference (WATTC‑88) agreed the International Telecommunication Regulations (ITRs) as the basic rules for international telecommunications. The original ITRs aimed to promote the development of telecommunication services and their most efficient operation while harmonizing the development of facilities for worldwide telecommunications. They helped establish the international accounting rates and defined procedures on how to agree the level of these rates as well as how to settle accounts and in what form to provide this detail. This agreement helped pave the way for the liberalization of the telecommunication industry and the explosive growth in international telecommunication traffic throughout the 1990s. In 1992, certain standards-setting activities of the CCIR (International Radio Consultative Committee), and those of the CCITT, were brought together to form the Telecommunication Standardization Sector (ITU–T), with effect from 1993.
Enter the Internet — An era of explosive growth
ITU–T specifications were widely used in earlier forms of Internet access over telephone lines, such as via cable modem. ITU–T approved its ITU–T J.112 standard for modulation protocols for interactive cable television services in 1998 for high-speed, bi-directional IP data transmissions. Recommendation ITU–T J.117, approved in 1999, covers the connection of cable television feeds into digital high-definition television (HDTV) sets.
By the mid-eighties, many carrier backbone networks and telephone exchanges were already digital. In 1986, the ITU-CCITT Study Group VIII and the ISO/TC97/SC2/WG8 group formed the Joint Photographic Expert Group (JPEG), which resulted in ITU–T Recommendation T.81 ISO/IEC 10918‑1, first approved by ITU in 1992, specifying a process for digital compression and the coding of continuous-tone still images. Today, this standard is known by the name of the group, JPEG, a breakthrough format still widely used for photographs on the Internet.
ITU also produced a key security standard, Recommendation ITU–T X.509, published in 1988 for public key infrastructure (PKI) or electronic authentication over public networks. This is widely used in a range of applications from securing the connection between a browser and a server on the web to providing digital signatures enabling e‑commerce transactions.
Recommendation ITU–T D.1, published in 1991, was another key factor in the growth of the Internet, as it obligated telecom operators to provide and connect leased lines to the Internet. It therefore became possible for Internet Service Providers (ISPs) to lease lines from telecom operators for Internet traffic. Leased lines are still needed to build corporate networks and serve as access circuits for Frame relay, ATM, IP-VPNs and the Internet in many developing countries today.
All ITU–T study groups have also focused on security-related questions to combat growing threats to network security, with nearly a hundred ITU–T Recommendations addressing this issue. ITU–T’s work on security covers a wide area, including studies into: security from network attacks, theft or denial of service, theft of identity, eavesdropping, telebiometrics for authentication, security for emergency telecommunications and telecommunication network security requirements.
Market transformation and the transition to IP networks
The late 1990s and early years of the millennium saw an almost total transformation of the telecom/information and communication technology (ICT) industry. Recommendations ITU–T D.140 and ITU–T D.150 were published in the late 1990s to facilitate the shift from the accounting rate system to the termination rate system and to help harmonize the interconnection rates for international telephony.
For the early transition to IP networks, ITU–T standards on Bearer Independent Call Control (BICC) technology represented a historic step toward packet-based and broadband multimedia networks used to support legacy PSTN/N-ISDN services over packet-based (IP or broadband) backbone networks. ITU–T developed a number of early standards in Voice over Internet Protocol (VoIP), such as Recommendation ITU–T G.799.1 (specifying the functions and characteristics of VoIP gateways) and Recommendation ITU–T H.323 adopted in 1996 (used in videoconferencing and the delivery of voice, video and data over IP networks).
ITU’s H.264/AVC (Advanced Video Coding) standard, approved in 2002, was the first truly scalable video codec, delivering excellent quality for high-definition television, videoconferencing and 3G mobile multimedia. The video compression standard (ITU–T Recommendation H.264 or MPEG‑4 pt.10/ AVC) was jointly developed by ITU–T SG16 and the ISO/IEC Moving Picture Experts Group (MPEG) and is used in products from many companies (including Apple, Sony, BT, France Telecom, Intel, Motorola, Nokia, Polycom, Samsung, Tandberg and Toshiba) and services (such as over-the-air broadcast television, HD DVD and Blu-Ray disc formats, and a large number of deployments of direct-broadcast satellite-based television services). In 2008, ITU received a Primetime Emmy Award from the Academy of Television Arts & Sciences (ATAS) for its work on ITU–T H.264.
On security, the 2003 Recommendation ITU–T H.235 provides protocols for VoIP and videoconferencing calls to be authorized and securely routed, while protected against security threats through real-time multimedia encryption and PKI certificates.
Fibre passive optical networks
ITU approved an early set of standards for fibre networks in the late 1980s — most notably, ITU–T Recommendations G.707, G.708, and G.709 for communicating digital information over optical fibre. Subsequently, ITU also approved its ITU–T Recommendations (G.983.1, G.984.1/2) for Passive Optical Networks (PONs). A PON is a point-to-multipoint fibre to the premises network architecture in which optical splitters are used to enable a single optical fibre to serve multiple premises. PON technology is used in the local loop to connect residential and SME end-users premises in an all-fibre network. By eliminating expensive active network elements, PONs can enable telecom carriers to make significant savings. A PON configuration reduces the amount of fibre required, compared with point-to-point architectures. ITU also produced its first ITU–T G.984 (GPON) standard, representing a significant boost in both the total bandwidth and bandwidth efficiency through the use of larger, variable-length packets.
In order to avoid overlapping investments in different standards development organizations (SDOs), ITU–T is actively engaged in collaborating and cooperating with other forums. This collaboration is necessary to avoid duplication of work and the consequent risk of conflicting standards in the market place. ITU–T recognizes the valuable work also done in other institutions and is in a privileged position to cooperate with many of its relevant partners.
From the xDSL suite of standards to G.fast — getting the most out of copper
The first Digital Subscriber Line (DSL) standard was approved in 1993. Also in the 1990s, ITU–T approved its first ITU–T ATM (Asynchronous Transfer Mode) Recommendations as a key layer technology for many ADSL implementations today. Throughout the late 1990s and early years of the millennium, ITU–T continued work upgrading its ground-breaking suite of xDSL standards (see Figure). xDSL enables the use of standard copper telephone cables to offer services such as high-definition TV (HDTV), video-on-demand, videoconferencing, high-speed Internet access and advanced voice services, such as VoIP. Although governments and operators in many industrialized countries are now looking to deploy or upgrade to fibre networks, it is important to note that globally, in 2014, xDSL still accounted for over half of all Internet access lines in use worldwide.
Technological innovation continues, with further advances continuing to help prolong the lifetime of existing infrastructure. ITU–T Study Group 15 approved the Very high bit-rate Digital Subscriber Line 2 (VDSL2) standard in 2005, enabling telecom operators to offer triple-play video, Internet and voice services at speeds ten times faster than ADSL. Although many operators are extending fibre into their network, this can prove expensive and copper lines are not redundant today — indeed, the most exciting use of copper promises to be where it is used in conjunction with fibre. The ITU–T approved its G.fast ITU–T 9701 standard in December 2014, which continues the exciting work to get the most out of legacy copper lines. G.fast promises to deliver ’fibre-like’ speeds of up to 1 Gbps over short ranges. G.fast could be used by many operators as part of a Fibre-to-the-Distribution-Point (FTTdp) solution or as an ideal accompaniment to a fibre-to-the-premises (FTTP) roll-out, where fibre optic lines are used to link large premises like office or apartment blocks to the PSTN, and ordinary copper cables can be retained and used within the building to connect tenants or residents to high-speed services.
Looking to the future
ITU–T will continue to adapt and upgrade its work programme to meet the evolving requirements of its membership, including Sector Members and Member States. As Chaesub Lee, Director of the ITU Telecommunication Standardization Bureau (TSB) has stated, “sometimes standardization gets ahead of the technology, sometimes technology and the industry leads standardization”. Regardless of which is ahead at any point of time, ITU–T will continue its work in defining and shaping industry standards, maintaining and monitoring network performance and working with its industry partners and other SDOs to ensure the smooth operation of telecommunication/ICT networks, taking into account the accelerating convergence of technologies and industry sectors.
Standardization experts must consider the significance of ’trust’ in the digital ecosystem as well as value chains, taking into account the communications of cyber-physical systems such as billions of networked devices, things, and objects, and must preempt relevant technologies’ requirements on supporting trustworthy ICT infrastructures. How will standards bodies provide the required level of trust for such a ubiquity of connected devices, things, and objects? And in the presence of data collection, storage, processing, analysis, and sharing on such a massive scale, how can the telecom industry build reliable and resilient ICT infrastructure?
Embedding trust into the information society will provide a greater level of certainty, confidence, and predictability in network interactions, expanding their scope and benefits. To achieve this, ITU will work in harmony with other standards bodies to enhance the level of trust in the current digital ecosystem while also considering the impacts of possible future developments. ITU will continue to support smart, context/content-aware, user-centric technologies, while being cognizant of, and in turn informing, the relevant policy and regulatory debates and frameworks.
The value of ITU–T standards stems from the value of their development process. As a United Nations (UN) specialized agency, ITU’s standardization process must enable peer learning and knowledge exchange to assist developing countries in advancing their ICT infrastructure and encouraging economic development. The benefits of international and national standards should be open to all, as should the global meeting of expertise that drives their development. ITU–T’s success in cooperating and collaborating with other bodies such as the IEEE Standards Association is another key measure of the value of ITU–T standards.
These questions are multifaceted: there are a myriad of different perspectives to be considered, and ITU–T will work to provide the global standardization community with an open, neutral platform to bring cohesion to ICT innovation through year 2020 and beyond. ITU–T is committed to ensuring that its work represents the latest, and most modern, developments in telecommunication/ICT technologies, with up-to-date, easily usable standards that meet the needs and requirements of users.
This article is an adaptation from the brochure, ’CCITT: Fifty Years of Excellence’.