Millimetre wave frequency band as a candidate spectrum for 5G network architecture : a survey

In order to meet the huge growth in global mobile data traffic in 2020 and beyond, the development of the 5th Generation (5G) system is required as the current 4G system is expected to fall short of the provision needed for such growth. 5G is anticipated to use a higher carrier frequency in the millimetre wave (mm-wave) band, within the 20 to 90 GHz, due to the availability of a vast amount of unexploited bandwidth. It is a revolutionary step to use these bands because of their different propagation characteristics, severe atmospheric attenuation, and hardware constraints. In this paper, we carry out a survey of 5G research contributions and proposed design architectures based on mm-wave communications. We present and discuss the use of mm-wave as indoor and outdoor mobile access, as a wireless backhaul solution, and as a key enabler for higher order sectorisation. Wireless standards such as IEE802.11ad, which are operating in mm-wave band have been presented. These standards have been designed for short range, ultra high data throughput systems in the 60 GHz band. Furthermore, this survey provides new insights regarding relevant and open issues in adopting mm-wave for 5G networks. This includes increased handoff rate and interference in Ultra-Dense Network (UDN), waveform consideration with higher spectral efficiency, and supporting spatial multiplexing in mm-wave line of sight. This survey also introduces a distributed base station architecture in mm-wave as an approach to address increased handoff rate in UDN, and to provide an alternative way for network densification in a time and cost effective manner

Network capacity optimisation in millimetre wave band using fractional frequency reuse

Inter Cell Interference (ICI) is a major challenge that degrades the performance of mobile systems, particularly for cell-edge users. This problem arises significantly in the next generation system, as the trend of deployment is with high densification, which yields an ultra-dense network (UDN). One of the challenges in UDN is the dramatic increase of ICI from surrounding cells. A common technique to minimise ICI is interference coordination techniques. In this context, the most efficient ICI coordination is fractional frequency reuse (FFR). This paper investigates the FFR in UDN millimetre wave network at 26GHz band. The focus is on dense network with short inter site distance (ISD), and higher order sectorisation (HOS). The metrics used in frequency reuse is the signal to interference plus noise ratio (SINR) rather than the distance, as the line of sight in millimetre wave can be easily blocked by obstacles even if they are in close proximity to the serving base station. The work shows that FFR can improve the network performance in terms of per user cell-edge data throughput and average cell throughput, and maintain the peak data throughput at a certain threshold. Furthermore, HOS has a potential gain over default sectored cells when the interference is carefully coordinated. The results show optimal values for bandwidth split per each scenario in FFR scheme to give the best trade-off between inner and outer zone users performance

The impact of higher order sectorisation on the performance of millimetre wave 5G network

The fifth Generation (5G) mobile network will provide services with extreme data rate and latency demands compared to current cellular network, and provide massive capacity and connectivity to multitude of devices with diverse requirements and applications. Therefore, it is important to utilise all network resources to provide the 5G vision. In this paper, performance evaluations and impact of higher order horizontal sectorisation on next generation 5G mobile access is presented. The study has been focused on busy urban areas in high carrier frequency. Millimetre wave band has precious wide unexploited bandwidth that can be harnessed for mobile communication. The results for these scenarios show that higher-order horizontal sectorisation in millimetre wave based smallcell deployment can significantly increase the network capacity to meet the future requirement of 5G network, and provide high data rate and connectivity to huge number of devices. Moreover, beamforming can highly increase the data rate by efficiently increase signal power and suppress interference from unwanted directions

The impact of base station antennas configuration on the performance of millimetre wave 5G networks

In this paper, two scenarios have been considered for millimetre wave base station configuration. In the first scenario, the approach of Distributed Base Station (DBS) with remote radio units (RRU) is chosen as the envisioned architecture for future 5G network. This approach is compatible with cloud radio access network (C-RAN), as it has easier scalability and compatibility with future network expansions and upgrades. RRU has been used in this work as a way to sidestep the limited coverage and poor channel condition, which characterise millimetre wave band. This will minimise the number of required sites installation for the same quality of service (QoS). The results of this approach have shown significant improvements in terms of User Equipment (UE) throughput, average cell throughput, and spectral efficiency. In the second scenario, optimising antenna element spacing is considered in the base station array. The results show significant improvement in the network performance and provide better performance for cell-edge users in terms of data throughput

Design considerations of ultra dense 5G network in millimetre wave band

The fifth Generation (5G) network will provide services with extreme data rate and latency demands compared to current cellular networks, and provide massive capacity and connectivity to multitude of devices with diverse requirements and applications. In this paper, dense deployment of small cells in high carrier frequency is considered as the theme of future 5G network. Network densification depicted in this work includes densification over the frequency by the adoption of wider bandwidth in the millimetre wave band, and densification over the space through higher number of antennas, higher sectorisation order, and dense deployment of small cells. The reference signal received power (RSRP) and quality (RSRQ), and signal to interference plus noise ratio (SINR) have been considered as the metrics for the design evaluation. Our results show that network densification has significant importance in improving data rate to meet 5G vision. And that dense deployment of small cells has better performance over higher sectorisation order, due to the higher line of site coverage and lower interference in the former case. In addition, the results show that densification in term of increasing the antennas is also vital to enable spatial multiplexing through multi-input-multi-output and enable beamforming to improve SINR, which eventually improve the data rate. Foliage loss and rain at millimetre wave bands are significant, and therefore, their impact has been evaluated as well

Potential technologies to 5G network : challenges and opportunities

Recently, there has been a substantial growth in mobile data traffic due to the widespread of data hungry devices such as smart handsets and laptops. This has encouraged researchers and system designers to develop a further efficient network design. The objective of this paper is to overview the technologies that can support multi Gbps for future Fifth Generation (5G) network. This paper presents many challenges, problems and questions that arise in research and design stage. It concluded that the anticipated high traffic demands and low latency requirements stemmed from the Internet of Things (IoT) and Machine to Machine Communications (M2M) can only be met with radical changes to the network paradigm such as harnessing millimetre-wave band in dense deployment of smallcells. Future wireless system will include all types of smart features and applications that make 5G the most intelligent and dominant wireless technology

Improvement of 5G performance through network densification in millimetre wave band

Recently, there has been a substantial growth in mobile data traffic due to the widespread of data hungry devices such as mobiles and laptops. The anticipated high traffic demands and low latency requirements stemmed from the Internet of Things (IoT) and Machine Type Communications (MTC) can only be met with radical changes to the network paradigm such as harnessing the millimetre wave (mmWave) band in Ultra-Dense Network (UDN). This thesis presents many challenges, problems and questions that arise in research and design stage of 5G network. The main challenges of 5G in mmWave can be characterised with the following attributes: i- huge traffic demands, with very high data rate requirements, ii- high interference in UDN, iii increased handover in UDN, higher dependency on Line of Sight (LOS) coverage and high shadow fading, and iv-massive MTC traffic due to billions of connected devices. In this work, software simulation tools have been used to evaluate the proposed solutions. Therefore, we have introduced 5G network based on network densification. Network densification includes densification over frequency through mmWave, and densification over space through higher number of antennas, Higher Order Sectorisation (HOS), and denser deployment of small-cells. Our results show that the densification theme has significantly improved network capacity and user Quality of Experience (QoE). UDN network can efficiently raise the user experience to the level that 5G vision promised. However, one of the drawback of using UDN and HOS is the significant increase in Inter-Cell Interference (ICI). Therefore, ICI has been addressed in this work to increase the gain of densification. ICI can degrade the performance of wireless network, particularly in UDN due to the increased interference from surrounding cells. We have used Fractional Frequency Reuse (FFR) as ICI Coordination (ICIC) for UDN network and HOS environment. The work shows that FFR has improved the network performance in terms of cell-edge data throughput and average cell throughput, and maintain the peak data throughput at a certain threshold. Additionally, HOS has shown even greater gain over default sectored sites when the interference is carefully coordinated. To generalise the principle of densification, we have introduced Distributed Base Station (DBS) as the envisioned network architecture for 5G in mmWave. Remotely distributed antennas in DBS architecture have been harnessed in order to compensate for the high path loss that characterise mmWave propagation. The proposed architecture has significantly improved the user data throughput, decreased the unnecessary handovers as a result of dense network, increased the LOS coverage probability, and reduced the impact of shadow fading. Additionally, this research discusses the regulatory requirements at mmWave band for the Maximum Permissible Exposure (MPE). Finally, scheduling massive MTC traffic in 5G has been considered. MTC is expected to contribute to the majority of IoT traffic. In this context, an algorithm has been developed to schedule this type of traffic. The results demonstrate the gain of using distributed antennas on MTC traffic in terms of spectral efficiency, data throughput, and fairness. The results show considerable improvement in the performance metrics. The combination of these contributions has provided remarkable increase in data throughput to achieve the 5G vision of “massive” capacity and to support human and machine traffic

Proceedings of the CSE 2017 Annual PGR Symposium (CSE-PGSym17)

Welcome to the Proceedings of the second Annual Postgraduate Research Symposium of the School of Computing, Science and Engineering (CSE-PGSym 2017). After the success of the first symposium, the school is delighted to run its second symposium which is being held in The Old Fire Station on 17th March 2017. The symposium is organised by the Salford Innovation Research Centre (SIRC) to provide a forum for the PGR community in the school to share their research work, engage with their peers and staff and stimulate new ideas. In line with SIRC’s strategy, the symposium aims to bring together researchers from the six groups that make up the centre to engage in multidisciplinary discussions and collaborations. It also aims to contribute to the creation of a collaborative environment within the Research Centre and the Groups and share information and explore new ideas. This is also aligned with the University’s ICZ (Industrial Collaboration Zone) programme for creating cultural, physical and virtual environments for collaboration, innovation and learning

SPARC 2017 retrospect & prospects : Salford postgraduate annual research conference book of abstracts

Welcome to the Book of Abstracts for the 2017 SPARC conference. This year we not only celebrate the work of our PGRs but also the 50th anniversary of Salford as a University, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 130 presenters, the conference truly showcases a vibrant PGR community at Salford. These abstracts provide a taster of the research strengths of their works, and provide delegates with a reference point for networking and initiating critical debate. With such wide-ranging topics being showcased, we encourage you to exploit this great opportunity to engage with researchers working in different subject areas to your own. To meet global challenges, high impact research inevitably requires interdisciplinary collaboration. This is recognised by all major research funders. Therefore engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers