Fifth-generation mobile networks, also commonly referred to as 5G, are the next generation of telecommunication standards intended for data transfer in cellular networks. The technology is aimed at providing higher transfer capacity than currently used 3G and LTE networks and allowing simultaneous use by multiple devices without a decline in performance. The following paper analyzes the proposed candidates for a 5G network system to identify its chief differences from existing technology and determine areas of potential improvement.
Hardware and Software
It is important to understand that as of now, the term 5G does not refer to a single technological solution. Essentially, it encompasses a generation of technology – a concept that allows for a significant improvement in key parameters through a fundamental change of approach. Thus, 5G can be viewed as an umbrella term for several directions in research of mobile networks.
Currently, several companies have come forward with pilot projects that can be viewed as candidates for a 5G standard. However, neither of these has been approved for industrial adoption because they are in the early stage of development. In the absence of a single standard, the 5G is currently viewed as a technological solution that would meet several loosely defined criteria. The said criteria include data rates (100 Mbps for metropolitan areas and at least 12 Mbps per user in areas with tens of thousands of connections), at least 1 Gbps connection for multiple corporate users, the ability to sustain hundreds of thousands of simultaneous wireless connections, a significantly improved spectral efficiency compared to LTE networks, increased coverage, enhanced signaling efficiency, and a major decrease of latency compared to the fourth generation of technology (Vu, Liu, Debbah, Latva-aho, & Hong, 2017). Thus, to specify the probable parameters of the system, it would be reasonable to outline several features that will likely be used as a basis for the final product.
The most promising direction in a new generation of mobile networking is the use of millimeter-wave band transmission, which has the potential to fulfill some of the criteria specified above. Mobile communication utilizes radio waves to transmit data. The wavelength of a signal is determined by its frequency, with higher frequencies corresponding to shorter waves. The millimeter-wave transmission uses waves of frequencies between 30 and 300 GHz, in which the length of waves is measured in millimeters. According to the FCC (2016), several spectrum ranges have been allocated for the 5G technology: 28 GHz, 37 GHz, and 39 GHz bands for licensed use, 64-71 GHz band for unlicensed use, and 37-37.6 GHz band for shared access.
It should be noted that the allocated frequencies are much broader than the ranges allocated for previous generations, which ensures consistency of block sizes at 200 MHz and significantly increases total availability for flexible use (3.85 GHz range for licensed spectrum and a combined 14 GHz band for unlicensed spectrum, respectively). The chief advantage of millimeter-wave technology is the increase in data density. In comparison, the latest iteration of mobile networks, commonly referred to as 4G, uses the range of 700 MHz to 2.1 GHz, allowing for relatively high volumes of data encoded in a single transmission.
At the same time, the existing commercial iterations of millimeter wave technology operate at frequencies of up to 770,000 GHz, providing greater speed and higher bandwidth capacity. Also, the minimal size of antennas required for sending and receiving millimeter-wave signals are significantly smaller than those used for networks of previous generations. For hardware manufacturers, this advantage means that several antennas can be installed in a single device without compromising its ergonomics and aesthetic appeal. Such an approach would allow for the reception of signals at different wavebands, providing higher transmission speeds, more reliable connection, and higher connection capacity for multiple users (Roh et al., 2014).
At this point, it should be mentioned that millimeter-wave technology has several disadvantages. First, higher frequencies are more difficult to propagate at high distances, which means that the denser distribution of transmitters is required. Second, short waves suffer from greater distortion resulting from environmental interference, which is observable even during the interaction with relatively small objects such as raindrops (Mohapatra, Swain, Pati, & Pradhan, 2014). While both issues can be solved by the installation of a larger number of smaller antenna towers, it is currently unclear whether this approach would provide a cost-effective solution and allow utilizing the benefits of the technology.
Operation Principles
As was mentioned above, no single currently proposed technology exists that could be referred to as 5G. However, several attempts have been made by major players in the field, including Intel, Verizon, Qualcomm, and AT&T to develop possible solutions. Thus, it would be reasonable to analyze one of the candidates to determine the principles of 5G operation. In this regard, a cloud-native 5G architecture proposed by Huawei Technologies can be considered a suitable option due to its encompassing nature. The architecture in question is expected to consist of multiple cloud engines that would coordinate the use of services with different standards and ensure on-demand network deployment via multi-connectivity (Huawei Technologies, 2016). The necessary degree of flexibility is achieved by the introduction of three frequency layers.
The main layer used to ensure coverage and high capacity are placed in the range of 2 to 6 GHz, which is expected to provide an effective combination of coverage and capacity and is likely to be implemented as a band for commercial 5G use (Huawei Technologies, 2016). The second layer includes the frequencies below 2 GHz and provides wider coverage suitable for indoor use. Finally, the third level, allocated above 6 GHz, is reserved for scenarios where high data density is necessary and data transmission rates are more important. The diversification of requirements in different industries and areas of implementation is addressed by the creation of several network topologies, with each segment using its unique combination of function sets through network function virtualization. The network function sets also referred to as network slices, are designed and implemented using a unified network infrastructure, which greatly reduces subsequent implementation costs.
The network slices are arranged as a set of distinct structures, which provides opportunities to customize each service by industry requirements. Such differentiation also allows for the implementation of new technologies. For instance, the ultra-reliable and low-latency communication (uRLLC) category has strict latency requirements, which makes it suitable for application in remote management, including assisted driving, as well as vehicles controlled by artificial intelligence. Massive machine-type communications, on the other hand, requires a relatively small amount of network interaction, which can be achieved through a lower frequency range. Another fundamental shift proposed by Huawei is multi-connectivity, which is expected to reduce latency and increase connection speed.
As was already mentioned, a single frequency band does not allow for a connection that is both rapid and reliable, requiring the introduction of heterogeneous networks described above. Such an approach enables providing the end-users with a seamless experience that combines high speed with reliability and mobility of high and low-frequency ranges, respectively. The effect is achieved by establishing multiple concurrent connections to different layers of the network. The cloud radio access network (RAN) architecture relies on the integration of non-real-time function modules of different modes into a mobile cloud engine, creating an anchor for connection (Huawei Technologies, 2016). In comparison to the traditional approach, where several layers are aggregated into a non-real-time module and sent to access points, the new RAN is estimated to improve latency by approximately 10 milliseconds and reduces transmission investment by 15% (Huawei Technologies, 2016).
Areas of Implementation
The main areas of implementation of the new technology are the consumer and business segments, where it enables significant improvements in the quality of services. While it does not offer revolutionary changes for end-user experience, 5G may play an important role in the field of education due to the greater operability of multimedia information sources, improved opportunities for independent research, and greater interactivity of educational services. It is also important to mention that on a global scale, 5G technology has the potential to increase the accessibility of information, thus improving the learning capacity of a population in developed countries. Finally, it is necessary to acknowledge the effect of long-term cost reduction on the adoption of the technology on a global scale, which is expected to promote its use in the non-profit sector.
Conclusion
Currently, 5G technology is in the early stage of development. Nevertheless, the existing candidates show tremendous potential, both in terms of improving existing communication characteristics and implementation in new areas. It is thus possible to conclude that its eventual adoption will assist the development of new technologies, including AI-operated vehicles and the Internet of Things, and provide significant improvements in traditional areas, including education.
References
FCC. (2016). Fact sheet: Spectrum frontiers proposal to identify, open up vast amounts of new high-band spectrum for next generation (5G) wireless broadband. Web.
Huawei Technologies. (2016). 5G network architecture A high-level perspective. Web.
Mohapatra, S. K., Swain, B. R., Pati, N., & Pradhan, A. (2014). Road towards millimeter wave communication for 5G network: A technological overview. Transactions on Machine Learning and Artificial Intelligence, 2(3), 48-60.
Roh, W., Seol, J. Y., Park, J., Lee, B., Lee, J., Kim, Y.,… Aryanfar, F. (2014). Millimeter-wave beamforming as an enabling technology for 5G cellular communications: Theoretical feasibility and prototype results. IEEE Communications Magazine, 52(2), 106-113.
Vu, T. K., Liu, C. F., Debbah, M., Latva-aho, M., & Hong, C. S. (2017). Ultra-reliable and low latency communication in mmWave-enabled massive MIMO networks. IEEE Communications Letters, 21(9), 2041-2044.