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

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

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

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

Mobile IPv4 based procedure for loose coupling architecture to optimize performance in heterogeneous wireless networks

One challenge of wireless networks integration is the ubiquitous wireless access abilities which provide the seamless handover for any moving communication device between the different types of technologies (3GPP and non-3GPP), such as GSM (Global System for Mobile Communication), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE). This challenge is important as mobile users (MUs) are becoming increasingly demanding for services regardless of the technological complexities associated with it. To fulfill these requirements for seamless Vertical Handover (VHO) two main interworking architectures have been proposed by European Telecommunication Standards Institute (ETSI) for integration between the different types of technologies; namely, loose and tight coupling. On the other hand, Media Independent Handover IEEE 802.21 (MIH) is a mechanism which has been proposed by IEEE group to provide seamless VHO between the aforementioned technologies by utilizing these interworking architectures to facilitate and complement its work. The paper presents the design and analysis of a Mobile IPv4 (MIPv4) based procedure for loose coupling architecture with MIH to optimize performance in heterogeneous wireless networks. Analytical results show that our procedure provides seamless VHO with minimal latency and low packet loss ratio

A new processing approach for reducing computational complexity in cloud-RAN mobile networks

Cloud computing is considered as one of the key drivers for the next generation of mobile networks (e.g. 5G). This is combined with the dramatic expansion in mobile networks, involving millions (or even billions) of subscribers with a greater number of current and future mobile applications (e.g. IoT). Cloud Radio Access Network (C-RAN) architecture has been proposed as a novel concept to gain the benefits of cloud computing as an efficient computing resource, to meet the requirements of future cellular networks. However, the computational complexity of obtaining the channel state information in the full-centralized C-RAN increases as the size of the network is scaled up, as a result of enlargement in channel information matrices. To tackle this problem of complexity and latency, MapReduce framework and fast matrix algorithms are proposed. This paper presents two levels of complexity reduction in the process of estimating the channel information in cellular networks. The results illustrate that complexity can be minimized from O(N3) to O((N/k)3), where N is the total number of RRHs and k is the number of RRHs per group, by dividing the processing of RRHs into parallel groups and harnessing the MapReduce parallel algorithm in order to process them. The second approach reduces the computation complexity from O((N/k)3) to O((N/k)2:807) using the algorithms of fast matrix inversion. The reduction in complexity and latency leads to a significant improvement in both the estimation time and in the scalability of C-RAN networks