IEEE recently held its Brooklyn 5G Summit – which for all practical purposes provides an update on the current status of 5G from a technical, deployment and business case perspective.
While enthusiasm remains overwhelmingly high – there was a cautionary air to the event regarding what exactly is 5G in these early deployments. Is it really 5G or more like 4G+, 4.5G or perhaps even 4.9G?
The goals of 5G are highly ambitious – providing end users – whether human or machine – with a highly reliable, secure and resilient network that will deliver communication services anywhere and at any time, over any access technology, on any device. In addition, the vision of the 5G network is to deliver services that are contextual, personalized, responsive and in real-time; providing users with a consistent experience.
The three major usage scenarios defined for 5G include (1) enhanced mobile broadband; (2) ultra-reliable and low latency communications; and (3) massive machine type communications.
The challenge for 5G is building a network that can support the varied requirements of each of the key usage scenarios. This will require operators to fully embrace virtualization and cloud technologies. And while support for all three usage scenarios is the long game for 5G, the need for faster mobile broadband speeds is resulting in a slight shift in direction for 5G standards.
Enhanced Mobile Broadband Leads the Way
Most of the 5G standardization work has concentrated on the enhanced mobile broadband (eMBB) use case, which is the focus of 3GPP Release 15 (also known as 5G Phase 1). In fact, in order to meet the aggressive 5G deployment schedules of a handful of operators, 3GPP fast-tracked the Non-Standalone (NSA) 5G New Radio (NR) specification in support of mobile broadband services to the end of 2017, rather than the middle of 2018, in order to allow for 5G deployments as early as 2019. The standalone mode is still on track for mid-2018.
- NSA 5G NR will utilize the existing LTE radio and core network as an anchor for mobility management and coverage while adding a new 5G carrier. This is the configuration that will be the target of early 2019 deployments (in 3GPP terminology, this is NSA 5G NR deployment scenario Option 3). NSA operation requires aggregation of LTE-band and NR-band via dual connectivity
- Standalone (SA) 5G NR implies full user and control plane capability for 5G NR, utilizing the new 5G core network architecture also being done in 3GPP Release 15.
This acceleration in the standards is needed to meet the ever-increasing demands of global mobile broadband. According to the most recent Cisco Visual Network Index: Global Mobile Data Traffic Forecast Update (2016-2021), the average consumer's smartphone is expected to consume close to 7GB of data per month in 2021 up from 1.6GB of data per month today. In addition, emerging video-intensive use cases like augmented reality and virtual reality as well as the expected growth of mobile broadband in vehicles make it understandable why the 3GPP has chosen to accelerate the 5G NR schedule to make use of the enhanced mobile broadband benefits of 5G NR sooner, while addressing the larger vision of 5G NR in 2020 and beyond.
An example of the planned evolution of the mobile network towards 5G taking these interim steps is shown below:
Evolution Rather Than Revolution?
While this focus on enhanced mobile broadband has satisfied the near-term wishes of a handful of operators, there is also a growing contingent that believes the industry is really just extending 4G capabilities with new spectrum and new radio – when 5G, as envisioned by IMT-2020 and NGMN, is really about an entirely new network architecture.
In fact, some circles believe the current 5G path will result in technology that is sub-optimal or only halfway-improved, resulting in an inefficient investment.
Why move to 5G when the goals of faster speeds and improved latency can be achieved with LTE and its variants – LTE-Advanced (LTE-A) and LTE- Advanced Pro (LTE-A Pro)? Both of these support carrier aggregation and higher order MIMO techniques, while LTE-A Pro leverages both licensed and unlicensed spectrum, increased numbers of antenna paths and a multi-beam approach. Additionally, it can significantly increase network capacity without any additional spectrum or base stations and offers increased battery life of 10x greater than LTE.
The key attributes that define LTE-A Pro are:
- Data speeds in excess of 3Gbit/s (LTE-A: 1Gbit/s)
- 640MHz of carrier bandwidth (LTE-A: 100MHz)
- Latency: 2ms (LTE-A: 10ms)
While not quite the targets of what has been proposed by NGMN and ITU-T IMT-2020 for 5G, they offer a significant improvement over current LTE networks as well as a platform for the delivery of new services to new markets as the industry moves towards IoT with 5G.
LTE-A and LTE-A Pro have a long deployment lifecycle ahead given the current deployment statistics from GSA, illustrating that there remains significant growth opportunity left in LTE:
- 591 networks in 189 countries are offering commercial LTE service at the end of 1Q17.
- 195 operators in 95 countries have launched LTE-A or LTE-A Pro networks
- 19 operators have launched LTE-A Pro networks, with an additional 26 in trial
Current downlink speeds over these LTE-A or LTE-A Pro networks range from 100Mbit/s to over 1Gbit/s as shown below.
5G Hype Cycle
The market has created a lot of hype surrounding 5G. In fact, one could argue that the industry is clearly in the ‘peak of inflated expectations’ area of the hype cycle. In the case of both South Korea and Japan, their rush towards 5G is driven by the Olympics and the desire to leverage mobile technologies to provide an unparalleled viewing experience for those in attendance as well as the rest of its global audience.
In other markets, it is about first to market positioning in an effort to capture subscribers. For example, AT&T announced that 20 markets would benefit from its 5G evolution networks by the end of 2017. The only problem: they are technically LTE-A Pro, not 5G. But they are not alone. According to GSA, 18 operators have announced plans to launch pre-standard 5G services.
Regardless of the semantics, true 5G services and networks – based on the vision of NGMN and ITU-T IMT-2020 – will require far more than just new radios and antenna systems, but a network that is elastic, programmable and dynamically manageable, with NFV and SDN at its foundation and cloud native.
In the meantime, the industry is taking smaller steps to lay the foundation for 5G, with the brunt of the work left for 3GPP Release 16.
Perhaps NTT DoCoMo’s CTO Seizo Onoe’s prediction is right that the wireless industry only manages to achieve great leaps in technology in even-number generations – such as 2G and 4G.
As such, perhaps 6G is really the new 5G.