Fifth Generation Mobile Networks: Challenges And Perspectives

ABSTRACT

Fifth generation (5G) mobile network is not only the successor of its previous mobile networks (4G,3G,2G) but also the beginning of a new era in mobile communication. The 5G performance targets include greater speed, greater capacity, reduced latency, cost reduction, high resolution and larger bandwidth. It is anticipated that 5G technology will officially hit across the world by 2020. 5G technology is expected to be utilized widely for applications such as smart logistics, Internet of Things (IoT), driverless cars, and other such smart applications, which demand high speed internet. It includes many advanced features which makes 5G technology most dominant technology in future. In this paper we will discuss in detail about State of the Art Technology, challenges, current and future research ideas, case studies, threats and security features in 5G mobile networks.

Keywords – Mobile, Speed, Latency, Spectrum, Bandwidth, Wireless network, Frequency range.

INTRODUCTION

5G networks are the next generation of mobile internet connectivity beyond the 4G LTE mobile networks of today in terms of faster speeds and more reliable connections on smartphones and other devices than ever before. 5G technology has many advanced features potential enough to solve many of the problems of our routine life. The advancement, features and usability are much beyond the expectation of a normal human being. With its ultra-high speed, it is potential enough to change the history of a cell phone usability. With development well underway, 5G networks are anticipated to launch across the world by 2020, working alongside existing 3G and 4G technology to provide faster connections and reduced latency. Fourth-generation (4G) Long-Term Evolution (LTE) wireless technology provides the foundation for Fifth-generation (5G). Unlike 4G, which requires large and high-power cell to transmit signals over longer distances, 5G wireless signals will be transmitted via large numbers of small cell stations located in places. The use of small cells is necessary because the millimeter -- the band of spectrum between 30 GHz and 300 GHz that 5G relies on to generate high speeds can only travel over short distances and is subject to interference from weather and physical obstacles. In addition to improvements in speed, latency, bandwidth and capacity, 5G offers network management features like network slicing.

Network slicing is a powerful virtualization capability and one of the key capabilities that will enable flexibility, as it allows multiple virtual networks within a single physical 5G network. The greater elasticity brought about by network slicing will help to address the cost and flexibility requirements imposed by future demands. 5G networks will help power a huge rise in Internet of Things technology, providing the infrastructure needed to carry huge amounts of data, allowing for a smarter and more connected world.

A. 5G Architecture

The system model of 5G shown below is entirely an IP based model designed for the wireless and mobile networks. The system consists of a main user terminal and then a number of independent and autonomous radio access technologies. Each radio technology is considered as the IP link for the outside internet world. This IP technology is designed focusing to ensure sufficient control data for proper routing of IP packets related to a certain application connections.

B. Salient features of 5G

As from the above explanation we can confirm that 5G is better than the older generations. Some of the features of this technology is shown in the below diagram.

STATE-OF-THE-ART

5G standards are expected to release by 2020 and the following initial commercial deployment, research in 5G wireless networks has gained a lot of momentum with the emergence of new ideas and innovative solutions. The challenging 5G networks design targets including 1000x network capacity, 10-30x lower latency, 10-100x peak data rates and 10x energy efficiency have led to several innovations in the areas of edge computing and ultra-reliable low latency communications (URLLC), device-to-device and massive machine type communications (mMTC), among many other innovations. Development of 5G is being led by companies such as ZTE, Cisco, Lenovo, Nokia, Samsung and Ericsson for infrastructure and Huawei, Intel and Qualcomm for modem technology.

AT&S is supporting the 5G mobile communications generation with high frequency optimized interconnect solutions by producing hybrid-printed circuit board structures. Beyond mobile operator networks, 5G is also expected to be widely utilized for private networks with applications in IoT, critical communications and enterprise networking. Large quantities of new spectrum have been allocated to 5G, to support increased throughput requirements of 5G, particularly in millimeter-wave bands. The Federal Communications Commission of the United States freed up vast amounts of 0 bandwidth in underutilized high-band spectrum for 5G in 2016[2]. 5g technology has significant impact in the modem market which attracts the traditional cellular modem suppliers. Qualcomm announced its X50 5G Modem in October 2016 and in November 2017, Intel announced its XMM8000 and XMM8060 series of 5G modem, both of which have expected to release in 2019. MediaTek announced its own 5G solutions expected to release in 2020 production.

CURRENT AND FUTURE RESEARCH

A. Current Research

Several groups are working on the 5g standards. Here we shall see the research advancements of a couple of the groups along with their simulated test results,A group called MEITIS (Mobile and Wireless Communications Enablers for Twenty-Twenty Information Society) published their project recently. The simulations they executed evaluates the key performance indicators of 5G such as, average data usage during peak hours, rates of user data and volume of traffic area wise. Results of simulations showed that latency of a radio access network was below 1ms. Their project also included different architectures of radio access networks based on different volumes of traffic in variable environments [3]. EMPhAtiC project explores transmission of multiple-input-multiple-output (MIMO), a very flexible filter-bank, communication techniques based on relay and equalization [4]. Their recent deliverable proposes FBMC under channels of selective frequency. The only research body in the United Kingdom dedicated to 5G, 5GIC, accomplished a breakthrough in wireless speeds: 1Tbps speed in a wireless P2P communication network [5]. Members of the body are considering application services which offer extreme-low latency. Another project 5GNOW, (5th generation Non-Orthogonal Waveforms for Asynchronous Signaling) proposed an efficient and scalable air interface which disregards the traditional strict orthogonality and principles of synchronism which were followed in earlier network generations. Waveforms such as filter bank multi-carrier (FBMC), universal filtered multi carrier (UFMC) show a great deal of promise which can surpass orthogonal frequency division multiplexing (OFDM) in context of 5G [6]. In addition to design of multicarrier waveform, the 5GNOW project addresses aspects such as scarce signal processing and ultra-low latency transmissions. Recent deliverables of the project demonstrates Gabor signaling, which means the signal when expanded is the sum of shifts in scaled time-frequency of a prototype window.

B. Future Research

In the years to come, the new norm of cellular connectivity, 5G will be utilized. With speeds exponentially greater than 4G. This will lead to the shift in consumer behavior and perspective of communication using smart devices [7]. At the time, 5G is limited to fixed wireless access due to limitations from network operator’s infrastructure. This limitation of using millimeter wave spectrum doesn’t make it adept enough for passing through several solid objects. In other words, 5G is limited to point to point line of sight transmission. Huge number of use cases will see the light of day with 5G, especially IoT. Augmented reality(AR), Virtual reality(VR) and artificial intelligence applications will be benefited from the extreme low latency and massive data pipelines which 5G has to offer. 5G will also bring optical fiber connection like speeds for seamless 4K streaming [8]. Communication between cars and drones will allow them to coordinate with things in the environment they are situated. This is also thanks to the network of low latency from 5G. The IoT world which would allow thousands of devices to be connected to the network would be realized by the emergence of 5G. According to an interview with Björn Ekelund, Ericsson’s corporate research director, he has mentioned that,The emerging 5G technology is not be viewed only as a network for communication, but it would be much more offering a complete infrastructure for digital devices which includes the capability of computation and storage of data along with transmission. All devices that would be used for interaction, communication and business purposes would require the features which 5G has to offer.

A significant amount of research is being done in the cloud aspect as well. Cybersecurity would be another area of interest which should be given high importance for security reasons. As number of devices connected to 5G networks would increase exponentially then appropriate security measure have to be in place. Artificial intelligence (AI) would also play a crucial role in 5G as the infrastructure would have the required computations and calculations without human intervention to distribute the resources. There would be a lot applications relying on AI which would utilize cloud capabilities on offer [9]. The fast data transfer speeds which 5G offers would benefit business applications which utilize cloud-based solutions as it would be more responsive and low latency leads to consistence in performance. Consumer experience will be better by a huge margin who rely on such business solutions [10]. Improvement in daily enterprise activities on a wide array of businesses would be evident, raising the level for the organization’s productivity rate.

CHALLENGES

Here we discuss few challenges which cell phone network operators and other relevant organizations would face to roll out 5G to the masses.

A. Frequency bands

The LTE system currently in place operates with bands below the range of 3. 6GHz. In the early deployment of 5G, the frequency band with which it would operate is below 6GHz, which would be unlicensed. The sub 6GHz bands are set as the frequency bands on which new standards are formed for 5G called 5G NR [11]. This involves a task of designing hardware at millimetre waves, which is comparatively more complex than a low frequency range. Interoperability is essential across devices. Hence, the addition of frequency bands further increases the complexity. Cell phone manufacturers can have a hard time because of the miss in coordination of 5G frequency bands which are differentiated region wise.

B. Massive volume of data

The volume of data across networks is expected to increase exponentially due to technological advancements. As 5G network promises to offer fibre connection like speeds on a wireless network, every network operator has to capable enough to support massive data volume due to the capability of applications which offer UHD streaming, high quality video calls etc. , and the complexity with scalability and infrastructure will come into picture [11]. Because of a bigger bandwidth the issue with be with coverage.

C. Beamforming

5G wireless transmission technology would require beamforming method for efficient means of transmission and in order to reduce wastage of power. Utilizing an advanced antenna array system, beamforming technology would be able to precisely locate the location of a user and signal transmission will take place in that direction [11]. A significant level of processing would be required at the base station to achieve beamforming since it is a complex task to precisely locate devices. D. Low-LatencyDue to the ultra-low latency 5G promises to offer it opens up the opportunity of several smart devices which would benefit from the feature. Automated driving cars and mission critical applications are some of the examples. They would require the low latency service for guaranteed smooth operation. Delays would lead to disastrous results. Medical remote surgery applications would require the latency of less than one millisecond, even slight increase in latency could lead to death or injury. Low latency transmission would lead to trade-off in throughput, at a physical layer perspective. Some solutions to achieve this would be the inclusion of caching at the network edge, short transmission time interval utilization and mobile edge computing to list a few [12].

E. Security

Robust security architecture is essential for 5G since all aspects of our everyday interactions and communication would depend on it. Here are some basic security challenges in 5G network which were raised by Next Generation Mobile Networks (NGMN) [13],

1. Network Traffic: Due to the large number of devices connected on the network along with the emerging IoT devices security would be a concern.
2. Radio interface security: Since the encryption keys of radio interfaces are sent over channels which are insecure, the probability of eavesdropping and man-in-the-middle attacks are high.
3. Integrity of user-data plane: The user-data plane does not have any cryptographic protection. This rises the concern of integrity.
4. Denial of Service attacks: There are control channels which are un-encrypted and elements of network control which are visible. No security is in place for applications and data of configuration of end-user devices.

KEY INDUSTRIAL PLAYERS

5G is being taken very seriously by companies, as they want to prepare the technology that is expected to be key in the emerging world of the Internet of Things. Basically, if companies can be involved in the standards process, they can develop their solutions to these specific requirements [14]. Some of them are:

Ericsson: Ericsson is nurturing to establish itself as a leader in 5G. Generally, its strategy is focused on partnerships with local industry players such as Turk-cell, SK Telecom and Softbank. The company is working on 5G standardisation in the EU. They are coordinating the METIS-II EU project in-order to develop the overall design of the 5G radio system and a roadmap recommendation for 5G standardisation [14].

Huawei: Huawei is investing a lot of money into 5G, by the end of this year the investment will reach $600 million. It has taken some tentative steps towards 5G with its 4. 5G concept. The Chinese company had announced that it is cooperating with Europe’s 5G public-private partnership and will be working on five specific projects. Huawei also suggested that it will be spending £5 million per year on 5G research in Europe from this year (2018) [14].

Telstra: The Australian operator wants to use 5G to meet the requirements of the Internet of Things. It will roll it out by upgrading the existing LTE network. As in Australia the frequency around 700MHz formerly used by analogue television became free, Telstra has used a piece of this spectrum to deliver 4GX, which theoretically runs twice as fast as regular 4G. [14].

Nokia: Nokia is remembered by many as the maker of their first mobile phone handset, but Nokia regained its crown in the mobile arena, this time in the network rather than in hardware. At a Boston summit, Nokia Networks had demonstrated a system that can deliver speeds of up to 10 Gigabits per second, 40 times that which is available on current 4G. It being a part of European 5G PPP, Nokia is technically managing the METIS-II project as well as leading 5G radio access network design along with spectrum work packages [14].

Deutsche Telekom: European carrier network, Deutsche Telekom plans to invest more than €6 billion in its networks. Its current network runs at speeds of 300 Mbps. DT is also a leader in the global standardisation efforts through its chairmanship of the Next Generation Mobile Networks (NGMN) Alliance. This German operator had launched an innovation lab called 5G: Haus, teaming with European universities to carry out research [14]. Verizon: They switched on the first 5G network, initially covering four US cities.

The current network will serve as a last mile solution, delivering fast Internet to your home without cables. The 5G Home router will deliver “about 300Mbps” to houses in Houston, Indianapolis, Los Angeles and Sacramento. This is a fixed wireless access solution it replaces the broadband cabling coming to your home. 5G-enabled phones are on the way too, those will be made available to First on 5G members before other users [15].

CASE STUDIES

Living on the Edge: The Role of Proactive Caching in 5G Wireless Networks

This article explores one of the key enablers of beyond 4G wireless networks leveraging small cell network deployments, namely proactive caching. Endowed with predictive capabilities and harnessing recent developments in storage, context-awareness and social networks, peak traffic demands can be substantially reduced by proactively serving predictable user demands, via caching at base stations and users' devices. In order to show the effectiveness of proactive caching, we examine two case studies which exploit the spatial and social structure of the network, where proactive caching plays a crucial role.

Firstly, in order to alleviate backhaul congestion, we propose a mechanism whereby files are proactively cached during off-peak demands based on file popularity and correlations among users and files patterns. Secondly, leveraging social networks and device-to-device communications, we propose a procedure that exploits the social structure of the network by predicting the set of influential users to (proactively) cache strategic contents and disseminate them to their social ties via D2D communications. Exploiting this proactive caching paradigm, numerical results show that important gains can be obtained for each case study, with backhaul savings and a higher ratio of satisfied users of up to 22% and 26%, respectively. Higher gains can be further obtained by increasing the storage capability at the network edge [16].

CONCLUSION

5G Wireless Technology is more clever technology, which will interconnect the entire world without limits. It is designed in such a way that it provides unbelievable and extraordinary data capabilities followed with unhindered call volumes, and vast data broadcast. The future would have universal and uninterrupted access to information, communication, and entertainment that will dive into a new dimension of our lives and will modify our lifestyle meaningfully. As a matter of fact, the governments and regulators can use this technology as an opportunity for the excellent governance creating a healthier environment, which will encourage the continuity in the investment of 5G in the coming generations.