Mobile Access Networks Research Articles

Jointly optimizing user clustering, power management, and wireless channel allocation for NOMA-based Internet of Things

In order to accommodate the large number of Internet of Things (IoT) connections in mobile networks, Non-Orthogonal Multiple Access (NOMA) has been applied as the resource sharing mechanism in mobile access networks to improve the spectrum efficiency. The NOMA-based resource management for uplink communications comprises two problems, i.e., user clustering and power & wireless channel allocation. User clustering refers to assigning users in terms of IoT devices to different clusters (where users in the same cluster are sharing the wireless channels to upload their data), and power & wireless channel allocation is to optimize the transmission power of the users and the number of wireless channels allocated to the users in a cluster. The two problems are coupled together, thus making it difficult to solve the NOMA-based resource management problem. In this paper, we propose a QoS-aWarE resourcE managemenT (SWEET) for NOMA algorithm to jointly optimize the user clustering, power management, and wireless channel allocation such that the number of wireless channels is minimized and the data rate requirements of the users can be satisfied. The performance of SWEET is validated via extensive simulations.

Beyond 5G Network Architecture Study: Fractal Properties of Access Network

Wireless networks connect various devices through radio waves in which the network connection may have different structures. Moreover, the network structure is determined based on the placement areas of the network elements, which can be affected by the building and their locations. However, the numerical characteristic which describe the features of the real environment and allow them to be related to the properties of the model are still a challenge that has not been well addressed. To this end, in this paper, we analyze the modeling problems related to the structure of user placement in the access network. Our proposed solution is based on a description of the user environment structure in which cities in the form of buildings and constructions are considered as a typical environment. We propose a new model for addressing the wireless network structure in an efficient manner in which the features of the environment are considered, which are numerically expressed in the form of the Hurst parameter or fractal dimension. In addition, the fractal dimension, geometric fractals, and the characteristics of the user’s distribution territory and urban development are efficiently utilized. Then, we analyze the influence of the fractal properties of the environment on the structure of promising communication networks; in particular, on the structure of the Internet of Things network. Finally, simulation results proved that the proposed model is considered as a beneficial solution for modeling mobile communication and wireless access networks, including fifth-generation networks.

Federated Deep Reinforcement Learning for Internet of Things With Decentralized Cooperative Edge Caching

Edge caching is an emerging technology for addressing massive content access in mobile networks to support rapidly growing Internet-of-Things (IoT) services and applications. However, most current optimization-based methods lack a self-adaptive ability in dynamic environments. To tackle these challenges, current learning-based approaches are generally proposed in a centralized way. However, network resources may be overconsumed during the training and data transmission process. To address the complex and dynamic control issues, we propose a federated deep-reinforcement-learning-based cooperative edge caching (FADE) framework. FADE enables base stations (BSs) to cooperatively learn a shared predictive model by considering the first-round training parameters of the BSs as the initial input of the local training, and then uploads near-optimal local parameters to the BSs to participate in the next round of global training. Furthermore, we prove the expectation convergence of FADE. Trace-driven simulation results demonstrate the effectiveness of the proposed FADE framework on reducing the performance loss and average delay, offloading backhaul traffic, and improving the hit rate.

Combined time bound optimization of control, communication, and data processing for FSO‐based 6G UAV aerial networks

Because of the rapid increase of mobile traffic, flexible broadband supportive unmanned aerial vehicle (UAV)-based 6G mobile networks using free space optical (FSO) links have been recently proposed. Considering the advancements made in UAVs, big data processing, and artificial intelligence precision control technologies, the formation of an additional wireless network based on UAV aerial platforms to assist the existing fixed base stations of the mobile radio access network is considered a highly viable option in the near future. In this paper, a combined time bound optimization scheme is proposed that can adaptively satisfy the control and communication time constraints as well as the processing time constraints in FSO-based 6G UAV aerial networks. The proposed scheme controls the relation between the number of data flows, input data rate, number of worker nodes considering the time bounds, and the errors that occur during communication and data processing. The simulation results show that the proposed scheme is very effective in satisfying the time constraints for UAV control and radio access network services, even when errors in communication and data processing may occur.

An FSO-Based Drone Assisted Mobile Access Network for Emergency Communications

Deploying drone mounted base stations (DBSs) can quickly recover communications of mobile users (MUs) in a disaster struck area. That is, DBSs can act as relay nodes to transmit data from remote working base stations (which are located out of the disaster struck area) to MUs. Since DBSs could be deployed very close to MUs, the access link data rates between DBSs and MUs are well provisioned. However, DBSs may be far away from the remote working base stations, and thus the backhaul link data rate between a DBS and the remote working base station could be throttled. Free Space Optics (FSO), which has been demonstrated to provision high speed point-to-point wireless communications, can be leveraged to improve the capacity of the backhaul link. Since FSO requires line-of-sight between a DBS and a remote working macro base station, DBSs have to be carefully deployed. In this paper, we design a QoS awa R e dron E base S tation pla C ement and mobile U ser association strat E gy (RESCUE) in the context of FSO based drone assisted mobile access networks to jointly optimize the DBS deployment, MU association, and bandwidth allocation such that the number of served MUs in the disaster struck area is maximized. The performance of RESCUE is validated via extensive simulations.

Reliability and Mobility Load Balancing in Next Generation Self-organized Networks: Using Stochastic Learning Automata

Self-organizing networking (SON) is an automation technology designed to make the planning, configuration, management, optimization and healing of mobile radio access networks simpler and faster. Most current self-organization networking functions apply rule-based recommended systems to control network resources which seem too complicated and time-consuming to design in practical conditions. This research proposes a cognitive cellular network empowered by an efficient self-organization networking approach which enables SON functions to separately learn and find the best configuration setting. An effective learning approach is proposed for the functions of the cognitive cellular network, which exhibits how the framework is mapped to SON functions. One of the main functions applied in this framework is mobility load balancing. In this paper, a novel Stochastic Learning Automata has been suggested as the load balancing function in which approximately the same quality level is provided for each subscriber. This framework can also be effectively extended to cloud-based systems, where adaptive approaches are needed due to unpredictability of total accessible resources, considering cooperative nature of cloud environments. The results demonstrate that the function of mobility robustness optimization not only learns to optimize HO performance, but also it learns how to distribute excess load throughout the network. The experimental results demonstrate that the proposed scheme minimizes the number of unsatisfied subscribers (Nus) by moving some of the edge users served by overloaded cells towards one or more adjacent target cells. This solution can also guarantee a more balanced network using cell load sharing approach in addition to increase cell throughput outperform the current schemes.

Long Term Evolution -Self Organizing Network for Minimization of Sudden Call Termination in Mobile Radio Access Networks

Nowadays the mobile devices have become a more vital requisite and very crucial portion of our lives daily routine. The sudden call termination that happens unexpectedly (call drops) is a circumstance were the enduring calls get cut without any prior indication. The evolution of the services associated with the 3G and the 4G based on the voice and the data has ended up in high conflicts between the companies of the telecommunication to increase the consumer rate leading to major occurrence of the termination in the calls. Such abrupt un-notified call cessation still remains as an unanswered question in the telecommunication industry all over the world. Manifold measures and the researches put forth to devise the solution to the issue of un-notified call cessation for the mobile radio access networks were not successful as every methodology had its own advantages and as well as disadvantages. The laid out research made efforts to discover the reasons that for this un-notified sudden termination of calls, and examines the problem related with the termination of calls in each phase of the radio technology and puts forth the Self Organizing Network in the LTE for minimizing the factors that are related to the call termination and enhances the quality of the voice calls. Further brings down the expenses on the capital and the operations on terms of structural and the configuration attributes.

Duplexing mode, ARB and modulation approaches parameters affection on LTE uplink waveform

The next generation of radio technologies designed to increase the capacity and speed of mobile networks. LTE is the first technology designed explicitly for the Next Generation Network NGN and is set to become the de-facto NGN mobile access network standard. It takes advantage of the NGN's capabilities to provide an always-on mobile data experience comparable to wired networks. In this paper LTE uplink waveforms displayed with various duplexing mode, Allocated Resources Blocks ARB, Modulation types and total information per frame, QPSK and 16 QAM used as modulation techniques and tested under AWGN and Rayleigh channels, similarity and interference of the generated waveforms tested using auto-correlation and cross-correlation respectively.

Distributed Blockchain-Based Trusted Multidomain Collaboration for Mobile Edge Computing in 5G and Beyond

Mobile edge computing (MEC) sinks computing power to the edge of networks and integrates mobile access networks and Internet services in 5G and beyond. With the continuous development of services, privacy protection is extremely important in a heterogeneous MEC system for multiserver collaboration. However, most of the existing schemes only consider the privacy of users or services other than the privacy of network topology. For the purpose of topology privacy protection, this article employs blockchain to construct heterogeneous MEC systems and adopts accommodative bloom filter as a carrier for multidomain collaborative routing consensus without exposing topology privacy. Blockchain is used to implement multiplex mutual trust networking and collaborative routing verification through the membership service and consensus mechanism. Experiments are conducted to evaluate the feasibility and performances of our scheme. The results indicate that the proposed scheme can highly improve the credibility and efficiency of MEC collaboration.

Jointly Optimized 3D Drone Mounted Base Station Deployment and User Association in Drone Assisted Mobile Access Networks

In drone assisted mobile networks, a drone mounted base station (DBS) is deployed over a hotspot area to help user equipments (UEs) download their traffic from the macro base station (MBS), thus improving the throughput and spectrum efficiency (SE) of the UEs. Finding the optimal 3D position of the DBS to maximize the overall SE of the UEs in the hotspot area is challenging because the 3D DBS placement and user association problems are coupled together. In this paper, we formulate the problem of jointly optimizing the 3D DBS placement and user association to maximize the overall SE in the context of drone assisted mobile networks. The spectrum efficiency aware DBS placement and user association (STAR) algorithm is designed to decompose the original problem into two subproblems, i.e., user association and DBS placement, and to iteratively solve the two subproblems until the overall SE of the hotspot area cannot be improved further. The performance of STAR is demonstrated via extensive simulations.

FSO as backhaul and energizer for drone-assisted mobile access networks

Abstract Drone mounted base stations (DBSs) can be flexibly deployed over some areas (such as hotspots and disaster struck areas) to speed up the communication between terrestrial base stations (TBSs) and users. In order to increase the capacity of the backhaul link between a DBS and its TBS, free space optical (FSO) communications is applied as the backhaul solution. However, the DBS and its TBS should be in line-of-sight (LoS). Thus, a new DBS placement method is introduced to maximize the number of served users while guaranteeing the LoS between the DBS and its TBS. In addition, in order to prolong the hovering time of a DBS, we propose to deploy an optical beam to facilitate simultaneous communications and charging. That is, an optical beam transmitted from a TBS to its DBS carries not only data but also energy. The DBS mounted with a solar panel and an FSO receiver receives both the data and energy carried by the optical beam simultaneously. Numerical results demonstrate that using an optical beam to charge and communicate with a DBS can gain 25% extra hovering time of the DBS and achieve high network throughput.

Server Placement and Selection for Edge Computing in the ePC

Mobile Edge Computing (MEC) has received much attention from the research community in recent years. A significant part of the published work has studied the telecom-centric MEC architecture, which assumes that the computing resource is located at the edge of the mobile access network (e.g., the Evolved Packet Core or ePC), typically at the first aggregation level. Many of these studies make a silent assumption that the latency at this stage of the network is negligible. We show not only that this assumption is false, but that in some common cases the latency of the first aggregation stage dominates the end-to-end latency. We further show that common probing metrics can easily fail when used to select the service site for an application and discuss possible improvements to server-selection reliability.

First 20 Years of Green Radios

Green radios jointly consider the spectrum efficiency and the energy efficiency in wireless networks in order to provide sustainable development. In the past two decades, various green radio solutions for different types of terminals and radio access networks have been developed, some of which have been used in the designs of wireless products. In this paper, we provide a historical view on some fundamental works and practical issues. In addition to providing a comprehensive overview on theoretical achievements, we also discuss several important power saving solutions with notable engineering impacts, such as Doherty power amplifier and separated baseband unit - remote radio unit architecture, which might be overlooked in previous publications. Moreover, with the huge growth of wireless traffic in the near future, green radio design for future wireless networks shall involve an end-to-end energy efficiency investigation of mobile terminals, radio access and core networks, and different applications. By introducing green radio schemes for advanced terminals and future wireless networks, this article will not only be beneficial for readers with only preliminary background in communications and signal processing but also have reference and historical values for researchers and practical engineers in the area.

Heterogeneous mobile network access control technology based on mutual trust mechanism

With the popularization of mobile communication equipment, the application scope of heterogeneous mobile networks is expanding. The diversity of network types and access methods of heterogeneous mobile networks also increases the number of security problems that exist in the network. In order to ensure the security of the heterogeneous mobile network, it is necessary to perform effective authentication and status monitoring on the mobile communication device requesting access to the heterogeneous mobile network. To this end, this paper proposes a heterogeneous mobile network access control technology based on mutual trust mechanism. Firstly, this technology designs a network system model based on mutual trust system. In this network structure, the mobile communication node needs to pass the verification of the security service system before access the network, which guarantees the security of the heterogeneous mobile network to a certain extent. In order to meet the network service quality requirements of mobile communication nodes, this paper adopts a naive Bayesian-based machine learning method to select the optimal access network in heterogeneous networks for mobile communication nodes. In order to prevent malicious nodes in abnormal state from destroying network security, this paper adopts the hidden node detection method based on hidden Markov model. The security service system is suspended to provide a trust service for the detected abnormal node, to make the security service system stop providing trust services for exception nodes and the exception nodes unable to continue using network services. In the simulation experiment, the security analysis of the algorithm and the effectiveness evaluation of the performance were carried out.

Putting Context in the Network Access of Mobile Applications Using Fuzzy Analytic Hierarchy Process

In this article, the authors present a design and implementation of a context-based network access mechanism for eliciting context information and adapting this information with mobile applications' network access management. This paper proposes a multi-criteria decision-making algorithm based on fuzzy analytic hierarchy process that allows for integrating four context criteria, namely location, network, time, and speed, with network access service management of mobile applications at run-time. This article evaluates the proposed mechanism in the Android operating system running on handheld smart phone devices. Evaluation results have revealed the significance of fuzzy analytic hierarchy process method in providing network access management features based on real-time assessment of user context.

QoS Management and Flexible Traffic Detection Architecture for 5G Mobile Networks.

The next generation of 5G networks is being developed to provide services with the highest Quality of Service (QoS) attributes, such as ultra-low latency, ultra-reliable communication, high data rates, and high user mobility experience. To this end, several new settings must be implemented in the mobile network architecture such as the incorporation of Network Function Virtualization (NFV) and Software-Defined Networking (SDN), along with the shift of processes to the edge of the network. This work proposes an architecture combining the NFV and SDN concepts to provide the logic for Quality of Service (QoS) traffic detection and the logic for QoS management in next-generation mobile networks. It can be applied to the mobile backhaul and the mobile core network to work with both 5G mobile access networks or current 4G access networks, keeping backward compatibility with current mobile devices. In order to manage traffic without QoS and with QoS requirements, this work incorporates Multiprotocol Label Switching (MPLS) in the mobile data plane. A new flexible and programmable method to detect traffic with QoS requirements is also proposed, along with an Evolved Packet System (EPS)-bearer/QoS-flow creation with QoS considering all elements in the path. These goals are achieved by using proactive and reactive path setup methods to route the traffic immediately and simultaneously process it in the search for QoS requirements. Finally, a prototype is presented to prove the benefits and the viability of the proposed concepts.

Last mile mobile hybrid optical wireless access network routing enhancement

This study focuses on mobile ad hoc networks (MANETs) that support Internet routing protocol imposing stringent resource consumption constraints of Quality of service (QoS). The mobile Internet causes the ongoing issue of inefficient use of the MANET resources due to its random nature of wireless environments. In this paper, the new improved architecture of the last mile mobile hybrid optical-wireless access network (adLMMHOWAN) is proposed and designed to tackle the arised issues. The proposed design is based on a unified wireless-wired network solution required the deployment of MANET-based wireless fidelity (WiFi) technology at the wireless front-end and wavelengths division multiplexing passive optical network (WDM PON) at the optical backhaul. The critical performance metrics such as network capacity and energy consumption based on modified AODVUU routing protocol using OMNeT++ software is analyzed with 2 scenarios, namely the number of nodes and mobility speed. This mode of communication results in better QoS network capacity of 47.07% improvement, with 26.85% reduction of lower energy resource consumption for mobile wireless front-end over passive optical network backhaul architecture when compared with the existing work of oRiq scheme that focus on improvement in MANETs.

Energy-Efficient Video-On-Demand Content Caching and Distribution in Metro Area Networks

The success of novel multimedia services, such as video-on-demand (VoD) is leading to a tremendous growth of Internet traffic. Content caching can help mitigate such uncontrolled growth by storing video content closer to the users in core, metro, and access network nodes. So far, fixed, and, especially, mobile access networks have evolved independently, leveraging logically (and often also physically) separate infrastructures. This means that mobile users cannot access caches placed in the fixed access network (and vice-versa) even if they are geographically close to them, and energy consumption implications of such undesired effect must be investigated. In this paper we perform an evaluation of energy-efficient VoD content caching and distribution under static and dynamic traffic in converged networks as well as in non-converged networks. We define an integer linear programming optimization problem modeling an energy-efficient placement of caches in core, metro, and fixed/mobile access nodes where energy is minimized by powering-on and -off caches located in different segments of the network and by performing an energy-efficient VoD-request routing. To deal with problem complexity, we propose an energy-efficient content caching and VoD-request routing heuristic algorithm, which is also adopted under dynamic traffic scenarios. Our results show how deploying caches in the access and metro network segments can reduce the overall energy consumption of the network. Moreover, results show how the evolution toward a fixed-mobile converged metro/access network, where fixed and mobile users can share caches, can reduce the energy consumed for VoD content delivery.

Agricultural Investment and Role of Commercial Farming in Benishangul-Gumuz Region: Evidence from Ethiopia

Agricultural investment remains the top strategy of the Ethiopian government to contribute to the national economy by changing the traditional farming to modern agriculture. In Benishangul-Gumuz regional state in the last two decades, a substantial amount of land has been transferred to domestic and foreign investors by both regional and federal governments. Hence, this study has aimed to generate information for better understanding of the system and the options available to promote the current agricultural investment and trend of agricultural investment to seize the challenges and harness the existing opportunities. The results revealed that found that the commercial farming is constrained by different factors; these includes lack of access to infrastructures (like electricity and irrigation facilities), unavailability of farm equipment (like combine harvester, thresher and cleaner), inadequate policy incentives, lack of access to improved crop varieties and livestock breeds, lack of access to market, low and volatile price of their produce, were mentioned among the others. On the other hand, availability of storage of grains, road, and mobile network access, ownership of tractor, fair interest rate and access to credit were mentioned as opportunities for the commercial farmers. Moreover, currently, commercial farming is contributing employment (temporary and permanent jobs) and marketing opportunities and income tax payment to the local community and the government. Therefore, we suggest that to tackle the challenges and seize the opportunities in commercial farming, quick government support in areas of infrastructure development, research and development and linking commercial farming with local and international markets is needed. Keywords: Agricultural Investment; technology; Benishangul-Gumuz DOI : 10.7176/JESD/10-3-03

Moving the Network to the Cloud: The Cloud Central Office Revolution and Its Implications for the Optical Layer

SDN and NFV have recently changed the way we operate networks. By decoupling control and data plane operations and virtualising their components, they have opened up new frontiers towards reducing network ownership costs and improving usability and efficiency. Recently, their applicability has moved towards public telecommunications networks, with concepts such as the cloud-CO that have pioneered its use in access and metro networks: an idea that has quickly attracted the interest of network operators. By merging mobile, residential and enterprise services into a common framework, built around commoditised data centre types of architectures, future embodiments of this CO virtualisation concept could achieve significant capital and operational cost savings, while providing customised network experience to high-capacity and low-latency future applications. This tutorial provides an overview of the various frameworks and architectures outlining current network disaggregation trends that are leading to the virtualisation/cloudification of central offices. It also provides insight on the virtualisation of the access-metro network, showcasing new software functionalities like the virtual \ac{DBA} mechanisms for \acp{PON}. In addition, we explore how it can bring together different network technologies to enable convergence of mobile and optical access networks and pave the way for the integration of disaggregated ROADM networks. Finally, this paper discusses some of the open challenges towards the realisation of networks capable of delivering guaranteed performance, while sharing resources across multiple operators and services.