Future mobile operator business models will be determined by the availability of access to 5G networks. Human data consumption and the projected increase in machine-type communication (MTC) for the Internet of Things (IoT) will create an unprecedented level of demand. To address this demand, operators will need new radio techniques that will give everyone and every “thing” access from anywhere and everywhere.
As attendees at the recent Brooklyn 5G Summit discovered while identifying the best steps towards the 5G future, this unprecedented level of access is necessary to make 5G a commercial reality. And the best way to address the need is with versatile radio solutions that combine existing technologies with new innovations.
Current technologies alone cannot meet future demand for wireless access
At the current rate of network evolution, almost 20% of the projected demand for wireless access cannot be profitably addressed by 2020. Streaming and cloud-based services and applications are the biggest demand drivers. They are enabled by better devices and richer applications and reinforced by trends to higher resolution screens. (See the Nokia Bell Labs Report “Who will satisfy the desire to consume?”)
But the unprecedented need of users to consume on any device and from anywhere is only half of the story. The other half will be dictated by the huge increase in the number of IoT devices that will need to access the network by 2020 and beyond. Also, the expected growth in virtual reality applications will enable a new generation of applications covering remote instruction, control, and exploration.
The new type of wireless network traffic that will emerge from all this activity will have different characteristics. It will have to handle the sporadic transmissions that will be generated by billons of devices. It will use small packet sizes and huge numbers of communication partners.
The recent report by Nokia Bell Labs estimates that the total number of IoT connected cellular devices will be between 1.6B and 4.6B by 2020. While these devices will add less data traffic compared to mobile broadband users, they will require more signaling to communicate with the network. By 2020 the expected daily network connections for IoT devices may increase by as much as 135 times the number of human generated connections.
Existing 3G, 4G/LTE (News - Alert) networks, combined with small cells and HetNets will not be able to provide the access needed for this new traffic. They will be overloaded with huge signaling overhead because these networks were never designed to handle this kind of use.
To enable uninterrupted access in this fully interconnected and programmable world, mobile operators need new, versatile radio access technologies.
5G frequency bands deliver anywhere and everywhere access
Versatility will be provided by multiple frequency bands. 5G radios will use bands from 400 MHz to 100 GHz. The lower frequency bands will provide good penetration that will enable coverage to support applications with high mobility and reliability.
Efficient use of the sub-6 GHz spectrum will require different carrier bandwidths and flexible spectrum aggregation techniques. Within this range, carrier bandwidths of 40-100 MHz and efficient spectrum aggregation techniques will be needed for sub-3 GHz FDD deployments. For 3-6 GHz spectrum, support for high contiguous carrier bandwidths of more than 100 MHz will be especially relevant. Higher frequencies will have several bands available to provide huge capacity and throughput.
New technologies to enhance access
Beyond frequency bands, there is industry wide consensus about most of the key technologies that will be needed to enable ubiquitous access.
5G will deliver efficient support for advanced multi-antenna processing and for a higher number of antennas compared to previous network technologies. This is needed regardless of whether the antennas are distributed, as in coordinated multi-point (CoMP) transmission and reception, or localized with large MIMO and massive MIMO. Antennas that support massive MIMO can be used to improve spectral efficiency via multi-stream transmission, or to form a narrow beam to increase transmission distance.
Operators will also need a new numerology/frame structure combined with dynamic uplink/downlink switching for more precise resource allocation to achieve near zero latency. The new 5G frame structure is self-contained and can accommodate large data packets transmitted efficiently with low overhead, as well as small, low latency performance packets that need to be scheduled frequently.
To further improve performance, air interface improvements that address cross-link interference will enable efficient interference rejection and cancellation. Meanwhile, the cost for machine communication will be lowered by removing unnecessary functions in transmitters and receivers. This includes narrowband transmission, reduced transmit power, limited downlink transmission modes, and device processing relaxation.
5G commercialization will mix existing and new technologies
Fortunately, mobile operators don’t have to replace everything they have already invested in to leverage new technologies. 5G radio systems will deliver extreme broadband, ultra-robust, low latency connectivity for human beings and the IoT by combining current technologies with unique innovations. Existing Radio Access Technologies (RATs) in both licensed and unlicensed bands will work with new RATs optimized for specific bands and deployments, scenarios, and use cases.
One example of this approach is the Nokia (News 
- Alert) AirScale Radio Access solution. Available today, AirScale provides pre-standard 5G radio access that can be connected to existing commercial packet cores and transport solutions. It leverages new innovations — Massive MIMO, a new numerology/frame structure, dynamic uplink/downlink switching, and cloud technology — and combines them with existing technologies.
AirScale can run all technologies simultaneously in one base station. It can use any architecture topology and scale to virtually unlimited capacity to meet the needs of massive IoT connectivity and 5G latency and throughput. And it includes a cloud-based Radio Access Network designed for open interfaces.
And by adding multi-connectivity for enhanced capacity, coverage, and mobility, operators can have a device’s radio resources connect to at least two different network points using different radio bands, different RATs, or different layers. Multi-connectivity supports the smooth introduction of 5G on top of LTE networks and enables 4G/5G real-time radio resource management with dynamic inter-RAT load balancing to maximize output.
Integration and innovation make 5G viable
User demand and expectations are two things mobile operators can’t control. The projected growth in demand for access needs 5G connectivity.
AirScale proves that operators do not have to throw out existing access infrastructures to enable ubiquitous 5G access. In fact, by planning for an integration of legacy and new technologies an investment in LTE is already an investment in 5G. Operators will be able to launch 5G earlier and at lower cost. They can migrate existing LTE infrastructure to early 5G services and move to full 5G commercial services as the standards become finalized.
Ultimately, it’s this type of integration of existing and new technologies that will make 5G viable for operators and give them unprecedented radio access. By leveraging the right combination of network assets, operators can transition to 5G commercial service as their business demands.
About the Authors
Head of 5G Market Development, Nokia
Paul Norkus, Nokia 5G Product Marketing Manager
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Edited by
Peter Bernstein
