By Alan Carlton, Senior Director Technology Planning for InterDigital
I don’t think the future just suddenly happens like turning a corner and magically a next generation appears. There are always signs and trends along the way that provide directional indicators as to how the future will likely take shape. 5G will be no different than previous generations whose genesis was seeded in societal challenges and emerging technologies often conceived or identified decades earlier.
5G wireless will be driven by more efficient network architectures to support an internet of everything, smarter and new approaches to spectrum usage, energy centric designs and more intelligent strategies applied to the handling of content based upon context and user behaviors. From these perspective technologies/trends like the Cloud, SDN, NFV, CDN (in the context of a greater move to Information Centric Networking), Cognitive Radio and Millimeter Wave all represent interesting first steps on the roadmap to 5G.
5G Requirements and Standards
The requirements of what makes a network 5G are still being discussed, however, the best first stab at such requirements is reflected in the good work of the 5GPPP (in Horizon 2020). Some of the requirements that have been suggested thus far have included:
- Providing 1000 times higher capacity and more varied rich services compared to 2010
- Saving 90 percent energy per service provided
- Orders of magnitude reductions in latency to support new applications
- Service creation from 90 hours to 90 minutes
- Secure, reliable and dependable: perceived zero downtime for services
- User controlled privacy
But besides requirements, developing a standardization process for 5G will also have a significant impact in making 5G a reality. While the process has not yet begun, it is very reasonable to say that as an industry we are at the beginning of what might be described as a consensus building phase.
If we reflect on wireless history seminal moments, they may be where the next “G” began. The first GSM networks rolled out in the early 1990’s but its origins may be traced back as far as 1981 (and possibly earlier) to the formation of Groupe Spécial Mobile by CEPT. 3G and 4G share a similar history where the lead time between conceptualization and realization has been roughly consistent at the 10 year mark. This makes the formation of 5G focused industry and academic efforts such as the 5GPPP (in Horizon 2020) and the 5GIC (at the University of Surrey) in 2013/14 particularly interesting.
Assuming history repeats itself, these “events” may be foretelling of when we might realistically expect to see 5G standards and later deployed 5G systems. Components of 5G Technology 5G will bring profound changes on the both network and air interface components of the current wireless systems architecture. On the air interface we see three key tracks:
- The first track might be called the spectrum sharing and energy efficiency track wherein a new, more sophisticated mechanism of dynamically sharing spectrum between players emerges. Within this new system paradigm and with the proliferation of IoT devices and services, it is quite reasonable to discuss new and more suitable waveforms.
- A second track that we see is the move to the leveraging of higher frequencies, so called mmW applications in the 60GHz bands and above. If 4G was the era of discussing the offloading of Cellular to WiFi, 5G may well be the time when we talk of offloading WiFi to mmW in new small cell and dynamic backhaul designs.
- A final air interface track that perhaps bridges both air interface and network might be called practical cross layer design. Context and sensor fusion are key emerging topics today and I believe that enormous performance improvements can be realized through tighter integration of this myriad of information with the operation of the protocols on the air interface.
While real infinite bandwidth to the end user may still remain out of reach in even the 5G timeframe, through these mechanisms it may be possible to deliver a perception of infinite bandwidth in a very real sense to the user. By way of example, in some R&D labs today organizations have developed a technology called user adaptive video. This technology selectively chooses the best video streams that should be delivered to an end user based upon user behavior in front of the viewing screen. With this technology today bandwidth utilization has improved 80 percent without any detectable change in quality of experience perceived by the end user.
5G’s Impact on the Network
5G will be shaped by a mash up (and evolution) of three key emerging technologies: Software Defined Networking, Network Function Virtualization and an ever deeper Content caching in the network as exemplified by the slow roll of CDN technology into GGSN equipment today (i.e. the edge of the access network!). This trend will continue deeper into the radio access network and, in conjunction with the other elements, create a perfect storm where an overhaul to the IP network becomes possible. Information Centric Networking is an approach that has been incubating in academia for many years whose time may now be right within these shifting sands.
Overall, the network will flatten further and a battle for where the intelligence resides either in the cloud or the network edges will play out with the result likely being a compromise between the two. Device-to-Device communications in a fully meshed virtual access resource fabric will become common place within this vision. The future may well be as much about the crowd as the cloud. If the cloud is about big data then the crowd will be about small data and the winners may well be the players who first recognize the value that lies here. Services in this new network will change. A compromise will be struck between the OTT and Carrier worlds and any distinction between the two will disappear. Perhaps, more than anything else 5G must deliver in this key respect.
Benefits and Challenges of 5G
Even the most conservative traffic forecast projections through 2020 will challenge the basic capabilities and spectrum allocations of LTE-A and current generation WiFi. Couple this with a recognition that energy requirements in wireless networks will spiral at the same rate as the traffic projections and add the chaos of the emergence of the 50 or 100 billion devices - the so called Internet of Everything - all connected to a common infrastructure, and the value of exploring a 5th Generation should quickly become apparent.
The benefits of 5G at the highest level will simply be the sustaining of the wireless vision for our connected societies and economies in a cost effective and energy sustainable manner into the next decade and beyond.
However, 5G will likely roll out into a world of considerably changed business models from its predecessor generations and this raises perhaps the greatest uncertainty and challenge. What will these business models look like? It is clear that today’s model where Carriers finance huge infrastructure investments but reap less of the end customer rewards is unsustainable over the longer term. Some level of consolidation will inevitably happen but 5G will also have to provide a solution for a more equitable sharing of the infrastructure investment costs. Just how these new business models take shape and how this new thinking might drive technological development is perhaps the greatest uncertainty and challenge for 5G development.
While the conversations around 5G continue to grow, there is still a long way to go before reaching full scale deployment. While we may be looking farther down the line, the development is already in place and companies are already starting to do research and development into areas that might be considered foundational in helping 5G prevail. WiFi in white space is an early embodiment of a new more efficient spectrum utilization approach that is highly likely to be adopted in a more mainstream manner in 5G. More than this, companies are also exploring new waveforms (new proverbial 4 letter acronyms that often characterize a technology generation) that outperform LTE “OFDM” in both energy efficiency, operation in new emerging dynamic spectrum sharing paradigms and also in application to the emerging challenges that the internet of things will bring.
About the Author
Alan Carlton is the senior director of technology planning for InterDigital where he is responsible for the vision, technology roadmap and strategic planning in the areas of mobile devices, networking technologies, applications & software services. One of his primary focus areas is 5G technology research and development. Alan has over 20 years of experience in the wireless industry.