Reza Arefi

Bio: Reza Arefi is an academic researcher from Intel Mobile Communications. The author has contributed to research in topics: Handover & Mobile database. The author has an hindex of 5, co-authored 5 publications receiving 134 citations.

Millimeter-Wave Evolution for 5G Cellular Networks

Abstract: SUMMARY Triggered by the explosion of mobile traffic, 5G (5th Generation) cellular network requires evolution to increase the system rate 1000 times higher than the current systems in 10 years. Motivated by this common problem, there are several studies to integrate mm-wave access into current cellular networks as multi-band heterogeneous networks to exploit the ultra-wideband aspect of the mm-wave band. The authors of this paper have proposed comprehensive architecture of cellular networks with mmwave access, where mm-wave small cell basestations and a conventional macro basestation are connected to Centralized-RAN (C-RAN) to effectively operate the system by enabling power efficient seamless handover as well as centralized resource control including dynamic cell structuring to match the limited coverage of mm-wave access with high traffic user locations via user-plane/control-plane splitting. In this paper, to prove the effectiveness of the proposed 5G cellular networks with mm-wave access, system level simulation is conducted by introducing an expected future traffic model, a measurement based mm-wave propagation model, and a centralized cell association algorithm by exploiting the C-RAN architecture. The numerical results show the effectiveness of the proposed network to realize 1000 times higher system rate than the current network in 10 years which is not achieved by the small cells using commonly considered 3.5 GHz band. Furthermore, the paper also gives latest status of mm-wave devices and regulations to show the feasibility of using mm-wave in the 5G systems.

Dynamic selection of spectrum access in a spectrum sharing context

Abstract: Briefly, in accordance with one or more embodiments, a wireless system may be controlled to operate via time-division duplexing (TDD) in a first mode and operate via frequency-division duplexing (FDD) in a second mode. The mode of operation may be selected based at least in part on the available spectrum not utilized by a primary spectrum holder (PSH) in the vicinity of the wireless system. In one or more embodiments, control of operation between TDD and FDD, or between different realizations of the same duplex scheme, may be implemented by a cloud spectrum broker/controller, and in one or more alternative embodiments, control of operation between TDD and FDD may be implanted by the operator of the wireless system as an alternative spectrum holder (ASH).

Global standards enabling a 5 th Generation Communications system architecture vision

Abstract: A vision of a 5th Generation Wireless Communication system is presented which targets the efficient integration of multiple, heterogeneous Radio Access Technologies in conjunction with an heterogeneous cell-type deployment and the application of new spectrum bands and spectrum usage paradigms, such as advanced sharing concepts leading to Quality-of-Service guarantees for incumbents and cellular licensees. This contribution further analyzes related key standards bodies and regulation institutions which are expected to play a major role in implementing the inherent technological components. The current working status in key bodies is outlined and expected trends and directions are summarized. As a conclusion, specific actions are proposed in order to drive SG technology development, standardization and regulation in an efficient and coordinated way.

Licensed shared access for wave cellular broadband communications

Abstract: Millimeter Wave (mmWave) communication, taking place in the frequency bands between 30 and 300 GHz, is widely considered to be a key-enabler of future Fifth Generation (5G) Cellular Communication Systems, which will be deployed starting by the year 2020 and will provide a capacity increase up to a factor of 10,000 compared to existing network infrastructures. Main drivers for this upcoming network vision include new spectrum resources and dense network infrastructures, both building on the additional resources provided by mmWave bands. While unused mmWave spectrum opportunities are still available in some regions, it is a fact that incumbents are already taking substantial portions of the spectrum in certain areas. In the framework of this paper, Licensed Shared Access (LSA) Spectrum Sharing technology is proposed to be used as a key enabler in such cases, i.e. for managing Quality of Service (QoS) guaranteed access for future 5G cellular systems, where incumbents are maintain priority access rights to mmWave spectrum.

Method for device configuration, database, mobile communication device and network entity

Abstract: A method for device configuration is described comprising storing information about whether a mobile communication system comprising a mobile communication device operates correctly when a configuration is applied in a context of a configuration history to the mobile communication device; receiving a request for a configuration to be applied to mobile communication devices; and determining a configuration to be applied to the mobile communication devices based on the stored information

User Association in 5G Networks: A Survey and an Outlook

Abstract: The fifth generation (5G) mobile networks are envisioned to support the deluge of data traffic with reduced energy consumption and improved quality of service (QoS) provision. To this end, key enabling technologies, such as heterogeneous networks (HetNets), massive multiple-input multiple-output (MIMO), and millimeter wave (mmWave) techniques, have been identified to bring 5G to fruition. Regardless of the technology adopted, a user association mechanism is needed to determine whether a user is associated with a particular base station (BS) before data transmission commences. User association plays a pivotal role in enhancing the load balancing, the spectrum efficiency, and the energy efficiency of networks. The emerging 5G networks introduce numerous challenges and opportunities for the design of sophisticated user association mechanisms. Hence, substantial research efforts are dedicated to the issues of user association in HetNets, massive MIMO networks, mmWave networks, and energy harvesting networks. We introduce a taxonomy as a framework for systematically studying the existing user association algorithms. Based on the proposed taxonomy, we then proceed to present an extensive overview of the state-of-the-art in user association algorithms conceived for HetNets, massive MIMO, mmWave, and energy harvesting networks. Finally, we summarize the challenges as well as opportunities of user association in 5G and provide design guidelines and potential solutions for sophisticated user association mechanisms.

Millimeter-Wave Massive MIMO Communication for Future Wireless Systems: A Survey

Abstract: Several enabling technologies are being explored for the fifth-generation (5G) mobile system era. The aim is to evolve a cellular network that remarkably pushes forward the limits of legacy mobile systems across all dimensions of performance metrics. One dominant technology that consistently features in the list of the 5G enablers is the millimeter-wave (mmWave) massive multiple-input-multiple-output (massive MIMO) system. It shows potentials to significantly raise user throughput, enhance spectral and energy efficiencies and increase the capacity of mobile networks using the joint capabilities of the huge available bandwidth in the mmWave frequency bands and high multiplexing gains achievable with massive antenna arrays. In this survey, we present the preliminary outcomes of extensive research on mmWave massive MIMO (as research on this subject is still in the exploratory phase) and highlight emerging trends together with their respective benefits, challenges, and proposed solutions. The survey spans broad areas in the field of wireless communications, and the objective is to point out current trends, evolving research issues and future directions on mmWave massive MIMO as a technology that will open up new frontiers of services and applications for next-generation cellular networks.

Where, When, and How mmWave is Used in 5G and Beyond

Abstract: Wireless engineers and business planners commonly raise the question on where, when, and how millimeter-wave (mmWave) will be used in 5G and beyond. Since the next generation network is not just a new radio access standard, but instead an integration of networks for vertical markets with diverse applications, answers to the question depend on scenarios and use cases to be deployed. This paper gives four 5G mmWave deployment examples and describes in chronological order the scenarios and use cases of their probable deployment, including expected system architectures and hardware prototypes. The paper starts with 28 GHz outdoor backhauling for fixed wireless access and moving hotspots, which will be demonstrated at the PyeongChang winter Olympic games in 2018. The second deployment example is a 60 GHz unlicensed indoor access system at the Tokyo-Narita airport, which is combined with Mobile Edge Computing (MEC) to enable ultra-high speed content download with low latency. The third example is mmWave mesh network to be used as a micro Radio Access Network ({\\mu}-RAN), for cost-effective backhauling of small-cell Base Stations (BSs) in dense urban scenarios. The last example is mmWave based Vehicular-to-Vehicular (V2V) and Vehicular-to-Everything (V2X) communications system, which enables automated driving by exchanging High Definition (HD) dynamic map information between cars and Roadside Units (RSUs). For 5G and beyond, mmWave and MEC will play important roles for a diverse set of applications that require both ultra-high data rate and low latency communications.

Control-Data Separation Architecture for Cellular Radio Access Networks: A Survey and Outlook

Abstract: Conventional cellular systems are designed to ensure ubiquitous coverage with an always present wireless channel irrespective of the spatial and temporal demand of service. This approach raises several problems due to the tight coupling between network and data access points, as well as the paradigm shift towards data-oriented services, heterogeneous deployments and network densification. A logical separation between control and data planes is seen as a promising solution that could overcome these issues, by providing data services under the umbrella of a coverage layer. This article presents a holistic survey of existing literature on the control-data separation architecture (CDSA) for cellular radio access networks. As a starting point, we discuss the fundamentals, concepts, and general structure of the CDSA. Then, we point out limitations of the conventional architecture in futuristic deployment scenarios. In addition, we present and critically discuss the work that has been done to investigate potential benefits of the CDSA, as well as its technical challenges and enabling technologies. Finally, an overview of standardisation proposals related to this research vision is provided.

On the Feasibility of Sharing Spectrum Licenses in mmWave Cellular Systems

Abstract: The highly directional and adaptive antennas used in mmWave communication open up the possibility of uncoordinated sharing of spectrum licenses between commercial cellular operators. There are several advantages to sharing including a reduction in license costs and an increase in spectrum utilization. In this paper, we establish the theoretical feasibility of spectrum license sharing among mmWave cellular operators. We consider a heterogeneous multi-operator system containing multiple independent cellular networks, each owned by an operator. We then compute the signal-to-interference-and-noise ratio and rate distribution for downlink mobile users of each network. Using the analysis, we compare the systems with fully shared licenses and exclusive licenses for different access rules and explore the trade-offs between system performance and spectrum cost. We show that sharing spectrum licenses increases the per-user rate when antennas have narrow beams and is also favored when there is a low density of users. We also consider a multi-operator system where BSs of all the networks are co-located to show that the simultaneous sharing of spectrum and infrastructure is also feasible. We show that all networks can share licenses with less bandwidth and still achieve the same per-user median rate as if they each had an exclusive license to spectrum with more bandwidth.