5 Things Worth Knowing About 5G

Fifth-generation technology, mostly known as 5G, is already stumping up millions of dollars in research even though the standards framework for next-generation communication networks is to be set within the time corridor 2017 - 2019 and first commercial solutions expected to go live during 2020. Equipment vendors and component manufacturers want a part of the action when this happens because the prize is too big to ignore: being part of the 5G standard opens up a treasure chest of future licensing and royalty revenues that will handsomely pay off the investment in creating an arsenal of technology patents. Industry leaders are therefore leveraging their know-how and hammering out initial pre-standard 5G solutions in the hope of influencing standards bodies, regulators and operators. 5G now implies an extremely bold and overly ambitious vision on how future communication networks encompassing both fixed and mobile infrastructure will combine computing smarts to deliver never-seen before services in industry verticals. Currently it’s a panacea for everything that everyone ever wanted in terms of connecting people and things, and as such, a moving target. So let’s review five basic things worth knowing about 5G.

Why 5G?

First- and second-generation technology (1G / 2G) in the nineties allowed us to phone each other or send SMS messages on the go. 3G networks extended the mobility concept to data exhange for emails and Internet browsing using standards such as UMTS and HSPA. 4G brings the LTE standard into play, enabling mobile broadband applications such as video, gaming, social media and a fluid Internet experience. 5G takes this concept severals steps further with many experts claiming it to be revolutionary instead of evolutionary. The basic idea is to further improve the coverage, capacity, speed and energy efficiency of broadband communications, and also connect appliances, security sensors, health gadgets, door locks - the Internet of Things - and even cars with each other. Ultimately 25 billion networked devices are envisioned and most of these require a very low bandwidth yet long battery life.

What exactly is 5G?

Trying to pin down exactly what a standard might look like 4 years from now is a bit of a murky business based on the smattering of alternatives emanating from companies, alliances and research bodies from different regions and countries across the world. Experts largely agree that the specs for 5G should achieve:

• an increase in capacity by factor 1000 to allow 10 000 times more traffic, necessary for connecting so many endpoints with each other
• peak data rates of 10 Gbps with at least a reliable 100 Mbps available wherever needed, so that full movies can be downloaded in seconds
• a decrease in latency by a factor of 100 into the low millisecond range, to guarantee that mission-critical control decisions in cars, robots and manufacturing tools be taken in time
• a dramatic decrease energy consumption such that low-bandwidth battery-powered devices can operate for at least 10 years

Next to these 10x - 100x - 1000x hard fact improvements, 5G is expected to include other measures of strategic importance to the network

• the integration and optimisation of fixed networks (fibre) into a heterogenous 5G specification to support wireless access. New network concepts are needed to ensure the target specs for an integrated fixed/mobile hybrid infrastructure are met
• multi-tiered network architectures will need to take data centers, cloud computing and other measures into consideration with the aim of bringing self-contained computing and communication capabilities closer to endpoints where they are needed, avoiding backhaul where possible
• the integration of public-private spectrum sharing (read cellular vs. WiFi) into the radio access network (RAN) to overcome the spectrum scarcity in order to achieve capacity and data speed demands

5G’s most crucial challenges

Amongst the many issues 5G needs to address, two particularly thorny obstacles lie ahead:

• Harmonization: 5G’s success and universal acceptance ultimately requires a single and unique worldwide standard. With the number of countries, players and interest groups involved, this will be no easy feat to achieve taking the scope of the undertaking and the time left for finding and committing to best-in-class technology ingredients from the many rivalling parties. It’s all about bringing the diverse viewpoints into one universally acknowledged specification in order to avoid fragmentation
• Spectrum scarcity: achieving 5G’s high capacity, high speed and low latency target benchmarks requires freeing up or dynamically re-using scarce spectrum resources. A previous blog post addresses some of the current issues involved with the spectrum crunch. 5G further exacerbates the situation because it needs to straddle both broadband traffic at blistering speeds (in higher frequency bands) as well as low data rate IoT devices across a wide coverage area (in lower frequency bands). 5G will most likely support public safety communications as used by police, fire brigades… too and they have their own specific security and reliability demands. Add to that the differing spectrum allocation charts by country, and you end up with a herculean task. In short, to achieve 5G’s agenda will require as many chunks of spectrum from 300 MHz - 30 GHz (centimeter wave radio) and 30 GHz - 300 GHz (millimeter wave radio) as possible.

The 5G standardization process

At the heart of 5G standardization is the International Telecommunications Union (ITU) who will define the constituent parts of the new specification called IMT–2020 based on ratification of candidate technologies submitted. The ITU is organised into three divisions (ITU-T, ITU-R, ITU-D), two of which will be deeply involved with IMT–2020. ITU-T will cover the standardisation process whereas ITU-R will manage international spectrum and radio frequency recommendations and regulations. Owing to the scope of 5G, many more organizations (eg. 3GPP, IEEE, IETF…) and companies will contribute candidate technology proposals than was the case for 4G which led to the LTE and WiMAX standards. ITU-R holds so called World Radio Conferences (WRC) every three to four years where international treaties governing the use of the radio-frequency spectrum and geostationary-satellite and non-geostationary-satellite orbits are reviewed, recommended and revised. The next WRC–15 is set for November 2015 and besides agreeing on freeing up further spectrum below 6 GHz for 4G, the conference will look at spectrum topics to be addressed in terms of 5G in the forthcoming WRC–19 slated for 2019. If all goes well, the IMT–2020 standard will be set in stone on time. Karri Ranta-Aho at Nokia Networks reveals an insightful standardization timeline in a recent blog.

Pre-standard 5G research projects

In the current exploration & pre-standardization phase, the field is beginning to heat up as companies, research projects and alliances hope to leverage their candidate technologies for IMT–2020 integration. National telecom initiatives, international associations, infrastructure equipment vendors and mobile network operators are teaming with academia across the world to make the 5G vision come true. They are working furiously on network and air interface prototypes in the hope of IMT–2020 adopting their solutions. Major infrastructure vendors such as Alcatel-Lucent, Ericsson, Huawei, NEC, Nokia, ZTE and others are investing considerable research resources outside of their home markets to ensure that they can pull the standardization strings to their advantage.
5G will be a heterogeneous solution encompassing networking, computing and storage in one programmable and unified infrastructure. It will utilize multiple spectrum and radio technologies and support three different kinds of profiles:

1. superfast broadband for video and augmented/virtual reality
2. low energy/low data rate for IoT devices
3. low latency for time-critical industrial, automotive and enterprise applications.

Getting anywhere close to this vision by 2020 will be quite a feat. But as they say “reach for the stars”. In the meantime, 4G’s LTE and its future derivatives still have plenty of mileage in reserve to bridge that gap.

Spectrum - private or public beachfronts?

Spectrum seems similar to real estate. At least that's the image that is conjured up by the often used analogy "public or private beachfront?".

You could argue the beach (spectrum) belongs to government (regulator) who should plan its best use for its people, either by selling it off (licensed spectrum) to an investor (carrier) with strict clauses for its development (cellular infrastructure coverage) and ensuing use by paying visitors (subscribers), or by keeping it a public space open and free to all (unlicensed spectrum). This seems like a pretty good analogy but it seems to ignore one key contributor that is throwing a spanner in the works: technology advancement, or more accurately, semiconductor improvements. Wireless data is exploding through the usage of new wireless handhelds and devices and there is no end in sight. The Internet-of-Things is looming, further intensifying the situation as seers predict everything with a current running through might potentially be a source of further wireless data. So all sights are set on "spectrum" to offer a cure, and governments (regulators) who ultimately own it. Indeed, we need more spectrum. And lots of it.

Spectrum is big money

Spectrum is where big money meets legislation meets high-tech, yet always bound to the perennial laws of physics. It's a billion-dollar industry that encompasses auctioning, immense investments for operators who build nation-wide networks, influenced by a constant stream of new technologies that improve connectivity for all. Proponents of the one camp (licensed) rightfully argue that the immense investments for carriers building nation-wide networks require long-term perspectives for ensuring a profitable business. The other side (unlicensed) maintain that only open policies guarantee fair and efficient use of the airwaves and lead to universal, affordable and ubiquitous broadband for all. A case of "Cellular" vs. "WiFi" is in the ring for the next round.

"Spectrum Crunch" - a myth?

The crux of the issue is that much of our spectrum, particularly around the "sweet spot" is already in use. At least that what the skeptics purport, creating a shortage or "spectrum crunch" myth. The truth is a little more varied and subtle though.

Click to enlarge

Radio spectrum extends for 3 kHz to 300 GHz and mobile phones currently operate between 700 MHz to 2.6 GHz in this range - the so-called "sweet spot" based on state-of-the-art technology. Note, that this sweet-spot spectrum block represents roughly just under 1 % of available "radio spectrum". Spectrum shortage? Well, yes, in a way, if  you regard what's exploitable using today's available technology. Just as broadcast AM radio in the early decades of the last century relied on valves and tubes for frequencies up to 15 kHz, today's semiconductor technology defines wireless communications around the 1 GHz mark. But what about tomorrow? 

First approach: making the best of "redundant" spectrum

To date specific blocks in the full radio spectrum range have been allocated for specific purposes or services by governments, and most of these are historical in context. For example blocks for maritime navigation, aeronautical navigation, public safety, broadcast TV etc. A true patchwork as can be seen in Sebastian Anthony's "wireless crunch" blog for ExtremeTech. Of course spectrum is a unique and therefore valuable resource, but it does differ from oil, gas, minerals etc. which face continuous depletion until none are left. Spectrum can be revitalized by closing older, inefficient services, as has or is being done for analog TV, or by making use of "white space" consisting either of unused spectrum blocks or guard bands between used blocks/frequencies that were required in prior times for broadcast and communications technology to work.

Technology advancements increase spectrum usage

As the needle of technology heads towards the future, better usage in existing spectrum blocks and new usage in regions higher on the spectrum map become available accordingly. Ever decreasing semiconductor process nodes ensure the implementation of mathematical algorithms providing better modulation techniques and other advancements that ultimately increase bandwidth and bit rate per Hertz of frequency. Of course at the heart of cellular and wireless communications is the trade-off in providing the best capacity (more bandwidth/higher bit rates using higher frequencies) for the largest possible coverage area (lower frequencies are better here). Broadly speaking, lower frequencies travel further than higher ones but cannot carry as much information. The current sweet spot for wireless communications is determined by these facts and primarily governed by what's technically possible based on state-of-the-art semiconductors. Advances in semiconductor technology will allow the sweet spot to travel further up the spectrum over time and provide better bandwidth. The diagram below shows how these advancements will ultimately lead to the still amorphous 5G technology as we get closer to the year 2020 where wireless Gigabit speeds will become reality.

Click to enlarge

Does your devices' antenna size still matter?

Fitting a large antenna or satellite dish on your roof works for great TV reception, but what about handheld/portable wireless communication devices? One of the limiting factors of wireless devices has always been the required size of the antenna for transmission and reception. Antennas "resonate" at one quarter of a frequency's wavelength. Taking this factor into account for the typical current "sweet spot" frequency at 1 GHz leads to a minimum necessary antenna size of 7.5 cm which resembles an acceptable cell phone size. At 300 MHz this increases to 25 cm whereas at 3 GHz we get down to 2.5 cm. In other words, higher frequencies spell out smaller device form factors, or more room for integrating antenna arrays, read MIMO et al. As these new antenna technologies come into play, data rates can be increased through better wireless performance in several respects, irrespective of the maximum bit rate achievable by the modem dictated by modulation techniques/Shannon's theorem.

Some worthwhile spectrum vs. technology resources

Spectrum, it's allocation, management and better exploitation through technology is a complex field in itself. Both free and subscription-based resources provide great insight into the issues at hand. Regarding today's 4G technology, we've reached the max in terms of squeezing as many bits as possible per Hertz of spectrum, as eloquently reported by Kevin Fitchard at Gigaom on wireless networks as workhorses of the web. A further great reference is Frank Rayal's blog looking at the capacity-coverage issue for licensed and non-licensed band. It investigates and compares differences in this respect for LTE and WiFi, both using a 20 MHz band. Certainly both camps have convincing points to advocate as we move further down the timeline. Telecoms and spectrum expert Gunjan Idrayan writes a regular insightful blog on spectrum and wireless with a particular focus on the situation in the United States and India. You'll also find some timeless articles about licensed and unlicensed spectrum as well as mobile broadband written by Peter Rysavy. Furthermore here's a short list of paid research that is well worth investigating if spectrum belongs to the core of your professional work.

The Global Spectrum Database PolicyTracker	http://bit.ly/THmNBb
Spectrum Auction Tracker Analysys Mason	http://bit.ly/1t5EQkV
2G, 3G, & 4G Mobile Network Subscriptions, Spectrum Licensing, Ownership, Infrastructure Contracts & Handset Shipments Database Signals and Systems Telecom	http://bit.ly/1lEZ63o

Spectrum for Mobile Broadband IDATE	http://bit.ly/1lEZGhx
Radio Spectrum Intelligence Tolaga Research	http://bit.ly/1mR4sc9

There are many more market research reports on the topic of spectrum available, and you can also stay on top of the latest worldwide events by signing up at wi360 (free). You will receive email alerts on new research and events regarding the specific topic of spectrum.

Spectrum's future

Governments that regulate spectrum and the technology sector that provides the devices for wireless access are both doing their best by squeezing the most out of a limited resource. Yet each of them works with a completely different heartbeat and thus the "divide" is increasing at an alarming level to the detriment of the consumer and subscriber. Wi-Fi over the past decade is a case in point how unlicensed spectrum has been addressed remarkably well at breakneck speed outside of government intervention. At the same time, network investments in the licensed spectrum must also remain a lucrative business for carriers. With the subscriber in mind, the golden age of raking in exorbitant cash amounts by governments through spectrum auctioning requires a future rethink.

Our spectrum future will be mapped out how well concepts from all parties will be mutually respected and implemented.