5G Mobile Communications
It is now seven years since LTE was standardized and six years since the launch of the first LTE networks. With new generations of mobile communication technology appearing every ten years or so, and network operators struggling to meet their users’ demands for bandwidth, research for 5G is already well under way.
The demands on 5G networks will be severe: network traffic is forecast to increase by a factor 1,000 over the next 10-12 years, while the growth of the Internet of Things suggests that the number of connected devices may reach 50 billion by 2020. At the same time, the network’s energy efficiency must increase enormously so that it can meet those demands with a power consumption and cost that are no greater than those of today.
The specification process for 5G is being driven by the International Telecommunication Union (ITU) under the name IMT-2020, following the schedule shown in the diagram. The ITU vision for 5G was published in 2015, and covers three main scenarios that span a wider range of use cases than before: enhanced mobile broadband, massive machine type communications, and ultra-reliable and low latency communications. The respective performance targets include a peak data rate under ideal conditions of 10 to 20 Gbps, a connection density of 106 devices per square kilometre, and a radio latency of 1 millisecond, although it should be stressed that these will not be achievable simultaneously. The ITU intends to refine these targets and to publish the detailed performance requirements for IMT-2020 in February 2017, along with a circular letter inviting submissions for candidate technologies. High-level descriptions of those technologies will then be due around June 2019, with the full candidate specifications due by February 2020.
In response, the Third Generation Partnership Project (3GPP) has begun a number of studies into 5G, which cover the requirements of the system and the air interface, the system architecture, and models of radio propagation at frequencies above 6 GHz. These studies are due to complete during 2016 as part of 3GPP Release 14. 3GPP then plans an ambitious design schedule in which there will be two phases for the specification work: Phase 1, completed by the second half of 2018, will focus on enhanced mobile broadband and will address the most urgent commercial needs for 5G, while Phase 2, completed by December 2019, will address all the identified use cases for IMT-2020.
The design of a new communication system will be a challenge for 3GPP, particularly in view of the wide range of usage scenarios, and the need for a Phase 1 design that will be forwards-compatible with IMT-2020. In the second part of this blog, we will discuss the technical solutions that are currently under investigation for 5G.