Nº 10 2013 > Academia — Innovating for society
Challenges to 5G standardization
Ramjee Prasad, Director of the Center for TeleInfrastruktur (CTIF) at Aalborg University, Denmark, and Founding Chairman of the Global ICT Standardization Forum for India (GISFI) and Albena Mihovska. Ms Mihovska is leading research and standardization in next-generation wireless communications at CTIF, Aalborg University, Denmark
Interoperable, ubiquitous and dynamic are key objectives for fifth-generation (5G) communication systems and applications. These characteristics are also at the core of the main challenges that researchers, manufacturers, regulators and standardization bodies face when designing targeted strategies for the successful deployment of 5G enabling technologies.
Evolution of standards
Wireless communication standards have seen a rapid and multidirectional evolution since the start of the cellular era in the 1980s with the launch of the analogue cellular systems. Soon after, digital wireless communication systems emerged in a quest to satisfy mobility, quality of service and ever-growing data.
Despite the large variety of existing communication systems, each development has been motivated by the same goal: to provide universal service facilities to users, while maintaining or increasing profitability. While both aspects of this goal are strongly dependent on novel and smart technologies, the latter has also been a key factor in impeding rapid regulatory agreements that could speed up the adoption of interoperability on various infrastructural levels. This is a pity, because such agreements would make it possible to exploit dynamic access technologies to the full extent.
Backward compatibility, technology- and site-sharing, and convergence are key technological elements that — jointly with adequate regulatory agreements — will enable ubiquity of communications on a highly personalized level. The vision of a 5G wireless communication system is one of universally deployable converging technologies that will enable wireless services and applications at a data rate of more than one terabit per second (Tbit/s), with coverage extending from a city, to a country, to the continents and to the world, that will enable user-centric mega-communications.
The challenges faced by standardization in relation to the next-generation wireless communication system (that is, 5G) are multifold. They are determined by the complexity of the emerging user and usage scenarios for which 5G must provide myriad high-quality services. Unlike single-purpose wireless systems, 5G will have the hard task of operating an ever-growing number of heterogeneous networked devices that can communicate with each other or with people or robots to satisfy dynamic and high-level user expectations.
The efficient wireless communication system that is needed will be able to follow the user regardless of location, and be able to adapt its traffic capabilities on demand in order to satisfy user and service requirements. Standardization work faces the tough challenge of responding to the high public demand for universal, dynamic, user-centric and data-rich wireless applications. The user-centric concept here also includes protection of privacy and maintenance of trust.
Both standardization and technology developers are facing the challenge of diverse 5G technological requirements carrying equal weight in the provision of 5G services and applications.
Technological solutions for 5G should make it possible to eradicate or, at least, control the potentially dangerous aspects of ubiquitous communication, in particular those related to security, trust and the protection of personal data. Technological solutions should also offer reliability and dependability.
Researchers focused for years on finding the “killer application” for emerging wireless systems, but today the danger comes from the application business model itself. In order to boost profits, service providers must enable access of personal data from one application to another, without allowing any visible control of what happens to the information afterwards. Beyond the technological challenges, this entails moral and ethical considerations, especially in relation to services and applications for critical infrastructure.
Thus, 5G standardization must define uncertainties relating, for example, to new threats to cybersecurity, trust or privacy; trends in economic growth around the world; public acceptance of wireless and applied-field technologies; and legislative restrictions. These uncertainties then have to be taken into account in regard to long-term trends in technological innovation, such as the increase in distributed computing, the new forms of ultra-fast wireless connectivity, miniaturization and automation, and an increasing focus on cost containment.
Communication, navigation, sensing and services
Convergence of technologies, ultra-high capacity, universal coverage and maximal energy and cost-efficiency are key characteristics of the 5G wireless system concept.
The enabling technologies converging into the 5G wireless system concept are communication, navigation, sensing and services. A determining factor for the first three is the availability of radio spectrum, through which information can be transmitted in relation to the service requested. Cognitive radio relies on sensing for better exploitation of the available spectrum, while high-frequency millimetre-wave bands used in terrestrial and satellite communications are able to satisfy the 5G capacity requirements and represent a solution to the limited availability of radio-frequency spectrum.
Small cell deployment within the coverage areas of cellular networks requires minimum pre-planning and can boost capacity, increase coverage and improve energy and cost-efficiency for the wireless provider, individual user and third parties that may be providing the communication interface. These benefits, however, may be partially lost because of increased interference and the inability of the network operator to manually configure the smaller cell to be properly detected and used by the mobile devices, or simply because of an inability to adapt to user needs. Proper self-optimizing procedures and protocols for fast network deployment and dynamic reconfiguration of small cells must solve the problem of how to deploy, where to deploy, and how to deal with the increased number of small cell sites. Such procedures and protocols thus carry the value of economically viable technological solutions.
5G services will rely on strong computational power to process the huge volume of data collected from various large-scale distributed sources. More specifically, 5G mobile devices will consume and produce data at the same time. Already today, most mobile devices are equipped with navigation capabilities (such as the Global Positioning System — GPS) and are able to report their location. The transfer of such an enormous load of information requires communication channels with the maximum possible capacity.
Novel antenna technologies and implementation of their hardware are crucial to maximizing throughput over the 5G communication channel. Beam forming with distributed elements is an interesting emerging technology, where the array elements are parts of different systems (that is, physically on different chips). This technology shows a potential for increasing the data throughput of distributed sources such as sensors or smart dust. On-chip integrated antennas can be used for distributed beam forming to maximize the data throughput of miniature sensor systems and other similar applications.
Using cloud computing capacities to provide and support ubiquitous 5G connectivity and real-time applications and services is a powerful way to automatically manage, analyse and control data procured from highly distributed and heterogeneous devices (sensors, actuators, smart devices). The cloud will be able to provide large-scale and long-lived storage and processing resources, as well as important backend resources, for the user-centric 5G ubiquitous applications delivered over the 5G wireless communication and network infrastructure.
5G business case
The 5G wireless communication system should seamlessly bridge the virtual and physical worlds, offering the same level of all-senses, context-based, rich communication experience over fixed and wireless networks. Because 5G will be a plethora of interworking technologies governed by separate specifications, it is important to find technological solutions and standardize interconnectivity in order to enable end-to-end telecommunication service provision across technologies and operators.
The successful 5G business case must adopt an active integration strategy that merges the different realms of the enabling technologies with new business opportunities. Standardization then becomes an enabler for both a successful technological and business concept.
The first challenge for 5G standardization and regulation is to adopt technological concepts and regulatory decisions that remove the limit on data rates. Each user should have ubiquitous personalized 5G wireless access at very high sustainable data rates approaching the current Ethernet state-of-the-art of 10+ gigabit per second (Gbit/s). A ubiquitous and pervasive wireless network offering a sustainable 10 Gbit/s (reaching a rate of up to 1 Tbit/s in burst mode) can be used as an alternative to Ethernet and access to Tbit/s fibre networks. Thus, standardization should evolve 5G as a “Wireless Innovative System for Dynamically Operating Mega-Communications” (WISDOM).
5G standardization faces the task of bundling multi-radio, multi-band air interfaces to support portability and nomadic mobility in a dynamic ultra-high data rate communication environment using novel concepts and cognitive technologies. Here, academic research and participation in standardization can play a crucial role. Standardization work should also recognize the specifics of the scenarios in various world regions (for example, developing countries) in order to stimulate profitable deployment and higher penetration worldwide.