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The initial deployment of the 5G service is based on 5G‐non‐standalone access option 3, also called dual EN‐DC connectivity. The selection of the 4G radio access network is initiated by the mobile. The synchronization signal identifies the cell with the physical layer cell identit. Cell re‐selection is also based on the public land mobile network priority list stored in the Universal Subscriber Identity Module module. The random access procedure is said to be with contention when the mobile randomly chooses the resources. The mobile synchronizes on the PCell of the target en‐gNB entity and performs the random access procedure without contention. The NG interface management procedure allows NG‐C interoperability information to be exchanged between the next‐generation radio access network node and the core network. A bandwidth part is a contiguous set of physical resource blocks, selected from a contiguous subset of the common resource blocks for a given numerology on a given carrier.

Providing seamless connectivity and services across national borders are intricate challenges with multifarious underlying aspects, ranging from the network management to business and political considerations. Since the cross-border inter-Public Land Mobile Network (PLMN) network handover is currently not available in European cellular networks, we present a complementary approach, diminishing the connectivity gap to a minimum. By leveraging Distributed Ledger Technology (DLT), we establish a dynamic, secure data exchange and management solution between several Mobile Network Operators (MNOs) of different countries. Systematically integrating foreign cell and base station parameter (i.e., Radio Access Network (RAN) data) of border regions into the internal network management systems permits their usage in standardized Mobility Management procedures. We demonstrate that this type of collaboration on the inter-MNO network governance considerably improves the network quality and customer experience when crossing national borders. Since foreign RAN data is also required for the inter-PLMN network handover (and can serve many additional purposes) and provided that our solution is not relying on any specific mobile network technology generation (e.g., 4G or 5G), we conclude that it is a fundamental step towards an inter-MNO ecosystem beyond 5G.

The drastic growth of mobile traffic greatly challenges the capacity of mobile infrastructures. Dense deployment of low-power small cells helps alleviate the congestion in the radio access network, yet it also introduces large complexity for network management. Software-defined radio access network has been proposed to tackle the added complexity. However, existing software-defined solutions rely on a fully centralized control plane to make decisions for the whole network, which greatly limits the scalability and responsiveness of the control plane. In this paper, we propose a hierarchical software-defined radio access network architecture. The proposed architecture leverages the hierarchical structure of radio access networks, deploying additional local controllers near the network edge. Utilizing the intrinsic locality in radio access networks, it offloads control tasks from the central controller to local controllers with limited overhead introduced. Under the architecture, a distributed optimization framework is proposed, and a typical optimization problem is studied to illustrate the effectiveness of the proposed architecture and framework. Both analysis and experiments validate that the proposed architecture and framework can improve the network objective during the optimization, meanwhile balancing load and improving scalability and responsiveness.

Unlike other radio signal services, 5G is anticipated to play a huge role in offering services to heterogeneous networks, technologies, and devices operating in different geographic regions to fulfill the high expectation of users with relatively low energy consumption, which implies the necessity for moving from a system-centric design to a more user- or even human- and data- centric design paradigm “to keep the human in the loop” in future network. It drives us to design a system with capacity to allocate network resource dynamically according to feedback from users. This paper presents a Human-In-The-Loop architecture for mobile network that discovers users’ needs on network resource by understanding data traffic usage behavior of users. Based on real data traffic of mobile network, we analyze data traffic patterns of heavy and normal users from the view of online browsing behavior and urban functional area to explain how and why the data traffic is consumed. Then we propose a Latent Dirichlet Allocation model based solution to correlate data traffic, user behavior, and urban ecology to gain deep insights into spatio-temporal dynamic of data traffic usage behavior for different groups of users. Drawing upon results from a comprehensive study of users in a metropolitan city in China, we achieve a broad understanding about the difference of data traffic usage patterns of heavy and normal user: (1) besides the amount of generated data traffic, two groups of users can be easily distinguished by usage behavior of limited number of applications at midnight, (2) the functions of locations have huge impact on data usage patterns of users, which implies that urban ecology will shape users’ online behavior. The results of this work can potentially be exploited to help to allocate network resource, improve Quality of Experience according to users’ needs, and even design the future network.

The demand of mobile traffic increases tremendously as various Internet services are provided to mobile phones and computing devices, making mobile carriers increase the capacity of their cellular network. Since current cell towers and auxiliary devices cannot carry an excessive amount of traffic, several mobile carriers try to install low cost wireless equipment such as a Wi-Fi access point (AP) in order to offload overloaded traffic on cell towers. However, APs are installed randomly unlike cell towers because they can be installed by anyone and anywhere. The randomized allocation of APs incurs interference that causes serious degradation of wireless communication quality. Therefore, it is necessary to design mobile devices to use the environment or channel that contains the least interference for proper Wi-Fi communication. In order to make a mobile device experience the best wireless download quality, this paper proposes a novel AP selection mechanism that selects an AP that contains the least interference level compared to others with different number of communicating devices and amount of traffic load. The proposed selection mechanism does not require any additional feedback from nearby devices or APs. Performance evaluation was done by using real mobile devices with open source platform called Android.

5G networks will support very diverse and challenging requirements. Network slicing offers an effective way to unlock the full potential of 5G networks and meet those requirements using a common network infrastructure. This article presents a cloud-native approach to network slicing that advances a fundamental rethinking of the mobile network to shift its architectural vision from a network of entities to a network of capabilities, and its driving purpose from a network for connectivity to a network for services. The approach covers the entire life cycle of network slices, encompassing their design, creation, deployment, customization, and optimization. We provide an overview of our cloud-native approach to network slicing and describe a proof-of-concept implementation that demonstrates its key principles.

Mobile crowdsensing is a new paradigm, sharing sensing data collected by mobile devices such as smartphones and tablets. As mobile devices are usually connected by an opportunistic network for data transfer, it is hard to acknowledge the contribution of each mobile user in network forwarding and find a sustainable incentive mechanism. In this article, we propose a software defined opportunistic network scheme for mobile crowdsensing. We design a centralized control structure to manage the opportunistic network and mobile crowdsensing. By the centralized structure, we also design an incentive mechanism for data forwarding and collection in a software defined opportunistic network and solve the optimal decision of mobile devices and the sensing service provider. From the extensive simulation results, our incentive mechanism performs better than original solutions.

Network slicing for 5G provides Network-as-a-Service (NaaS) for different use cases, allowing network operators to build multiple virtual networks on a shared infrastructure. With network slicing, service providers can deploy their applications and services flexibly and quickly to accommodate diverse services' specific requirements. As an emerging technology with a number of advantages, network slicing has raised many issues for the industry and academia alike. Here, the authors discuss this technology's background and propose a framework. They also discuss remaining challenges and future research directions. This publication was made possible by the NPRP award (NPRP 8-634-1-131) from the Qatar National Research Fund (a member of The Qatar Foundation), Huawei Technologies, and the China Scholarship Council (201506270075). The statements made herein are solely the responsibility of the authors. Scopus

Traffic volumes in mobile networks are rising and end-user needs are rapidly changing. Mobile network operators need more flexibility, lower network operating costs, faster service roll-out cycles, and new revenue sources. The 5th Generation (5G) and future networks aim to deliver ultra-fast and ultra-reliable network access capable of supporting the anticipated surge in data traffic and connected nodes in years to come. Several technologies have been developed to meet these emergent demands of future mobile networks, among these are software defined networking, network function virtualization, and cloud computing. In this paper, we discuss the security challenges these new technologies are prone to in the context of the new telecommunication paradigm. We present a multi-tier component-based security architecture to address these challenges and secure 5G software defined mobile network (SDMN), by handling security at different levels to protect the network and its users. The proposed architecture contains five components, i.e., secure communication, policy-based communication, security information and event management, security defined monitoring, and deep packet inspection components for elevated security in the control and the data planes of SDMNs. Finally, the proposed security mechanisms are validated using test bed experiments.

With the recent proliferation of powerful mobile devices, such as smart phones and tablets, data traffic on mobile networks is growing explosively. To cope with the challenges brought by the explosive growth of mobile traffic, mobile network operators tend to deploy and operate their own content distribution system within their existing network infrastructure. In this paper, we present a novel content distribution architecture called ISP-Controlled In-network Content Distribution (ICICD) to improve the content delivery performance in mobile network, which benefits from content request aggregation, hybrid cache decision mechanism, distributed load balancing, and seamless mobility support. Content request aggregation is used to decrease duplicate transmission. Hybrid cache decision mechanism enables the ICICD to cache content more efficiently. Distributed load balancing is able to ensure the overall performance and reliability of the content distribution architecture. Seamless mobility support function enables service continuity when mobile users move from one eNodeB to another. In this paper, we first give a detailed description about the key components of the ICICD architecture and then discuss a number of challenges in deploying the proposed ICICD architecture. Finally, simulation results are presented to show the performance and benefits of the proposed mobile content distribution architecture.

The increasing popularity and usage of portable smart devices have heightened the demand for higher data rates and mobility support in wireless communication networks. Many portable device users rely heavily on public transport during their trips to work, school, and other business locations. To facilitate the provision of high data rates for these commuters, the development of innovative wireless technologies is critical. Small cell networks can be a promising solution to this challenge. However, incorporating small cells in vehicular environments demands further investigation, especially for issues related to their communication architecture, interference and resource management. In this article, we present a small cell network system design that can provide seamless high data rate services to public transport users. We address the frequency allocation problem for mobile small cells and introduce time-varying frequency allocation solutions to meet the dynamic network topology and varying user traffic requirements.

As the Internet of Things (IoT) and the Web of Things (WoT) are becoming a reality, their interconnection with mobile phone computing is increasing. Mobile phone integrated sensors offer advanced services, which when combined with Web-enabled real-world devices located near the mobile user (e.g., body area networks, radio-frequency identification tags, energy monitors, environmental sensors, etc.), have the potential of enhancing the overall user knowledge, perception and experience, encouraging more informed choices and better decisions. This paper serves as a survey of the most significant work performed in the area of mobile phone computing combined with the IoT/WoT. A selection of over 100 papers is presented, which constitute the most significant work in the field up to date, categorizing these papers into ten different domains, according to the area of application (i.e., health, sports, gaming, transportation, and agriculture), the nature of interaction (i.e., participatory sensing, eco-feedback, actuation, and control), or the communicating actors involved (i.e., things and people). Open issues and research challenges are identified, analyzed and discussed. © 2014 IEEE. 3 6 885 898 Cited By :3

Network architectures based on mobile devices and wireless communications present several constraints (e.g., processor, energy storage, bandwidth, etc.) that affect the overall network performance. Cooperation strategies have been considered as a solution to address these network limitations. In the presence of unstable network infrastructures, mobile nodes cooperate with each other, forwarding data and performing other specific network functionalities. This article proposes a generalized incentive-based cooperation solution for mobile services and applications called MobiCoop. This reputation-based scheme includes an application framework for mobile applications that uses a Web service to handle all the nodes reputation and network permissions. The main goal of MobiCoop is to provide Internet services to mobile devices without network connectivity through cooperation with neighbor devices. The article includes a performance evaluation study of MobiCoop considering both a real scenario (using a prototype) and a simulation-based study. Results show that the proposed approach provides network connectivity independency to users with mobile apps when Internet connectivity is unavailable. Then, it is concluded that MobiCoop improved significantly the overall system performance and the service provided for a given mobile application.

With the emerging demands for local area services, mobile device-to-device (D2D) communications is conceived as a vital component for next-generation wireless networks to improve spectral reuse, to bring hop gains, and to enhance system capacity. In mobile D2D networks, energy-efficient probing schemes are vital to prolonging the limited battery life of mobile devices. Current solutions mainly focus on optimizing the probing interval during contacts by assumption of exponential distributed contact. However, studies in the area of network science have shown that the contact interval follows a power-law distribution, which indicates that the current solutions are not optimal while, on the other hand, dramatically increasing the difficulty of analyzing this problem. In this paper, we propose a network science approach for adaptive wakeup schedule based on power-law distributed contacts. Our approach requires nodes to stay asleep when a contact is unlikely to happen and to wake up only when the possibility that it successfully contacts another node is relatively high. By predicting node contacts in the future based on network science, our approach significantly reduces energy consumption without degrading the performance of opportunistic networks. Extensive simulations with real-life human and vehicular traces demonstrate the outstanding performance of our approach. The results show that our scheme saves 30% in energy while keeping the same performance in most scenarios, and it enhances the performance in terms of average delivery ratio and delivery delay by over 15%, compared with the existing best wakeup techniques, without considering network science.

Recently, mobile devices with multiple network interfaces are not only being used in the daily life but also across the entire industry in diverse ways and in many different sectors, including medical, health, education, business, and entertainment. Especially, analyzing the mobile usage patterns of users, there's been an increasing number of services that provide diverse types of content on an Internet-based environment, including video conferencing and VOD streaming services. For these kinds of services, due to the limitations imposed by the client/server architecture which involves going by a base station, the need for P2P is currently being emphasized, which allows direct communication between mobile devices. In order to improve the stability of mobile P2P services, however, there are challenges to overcome, including constraints of wireless communication (such as irregular bandwidth and frequent interrupts in the connection) as well as limitations of the mobile devices themselves (such as limited CPU and battery capabilities), which are classical mobile computing problems. Accordingly, this paper suggests a peer management policy for mobile P2P environments with high degrees of mobility which is designed to increase the efficiency of data transmission by taking sufficiently into account network characteristics and energy efficiency of mobile devices.

5G network is anticipated to meet the challenging requirements of mobile traffic in the 2020’s, which are characterized by super high data rate, low latency, high mobility, high energy efficiency, and high traffic density. This paper provides an overview of China Mobile’s 5G vision and potential solutions. Targeting a paradigm shift to user-centric network operation from the traditional cell-centric operation, 5G radio access network (RAN) design considerations are presented, including RAN restructure, Turbo charged edge, core network (CN) and RAN function repartition, and network slice as a service. Adaptive multiple connections in the user-centric operation is further investigated, where the decoupled downlink and uplink, decoupled control and data, and adaptive multiple connections provide sufficient means to achieve a 5G network with “no more cells.” Software-defined air interface (SDAI) is presented under a unified framework, in which the frame structure, waveform, multiple access, duplex mode, and antenna configuration can be adaptively configured. New paradigm of 5G network featuring user-centric network (UCN) and SDAI is needed to meet the diverse yet extremely stringent requirements across the broad scope of 5G scenarios.

In this paper, an extensive review has been carried out on the trends of existing as well as proposed potential enabling technologies that are expected to shape the fifth generation (5G) mobile wireless networks. Based on the classification of the trends, we develop a 5G network architectural evolution framework that comprises three evolutionary directions, namely, (1) radio access network node and performance enabler, (2) network control programming platform, and (3) backhaul network platform and synchronization. In (1), we discuss node classification including low power nodes in emerging machine-type communications, and network capacity enablers, e.g., millimeter wave communications and massive multiple-input multiple-output. In (2), both logically distributed cell/device-centric platforms, and logically centralized conventional/wireless software defined networking control programming approaches are discussed. In (3), backhaul networks and network synchronization are discussed. A comparative analysis for each direction as well as future evolutionary directions and challenges toward 5G networks are discussed. This survey will be helpful for further research exploitations and network operators for a smooth evolution of their existing networks toward 5G networks.

Online video service has become prevalent in recent years. A better understanding of the user behavior of such service is crucial for allocating the network resources and adjusting the service design. While there are some measurement studies on the non-mobile video services in fixed network, the usage of video service in mobile network is yet to be explored. In this paper, we present a detailed analysis of the user behavior characteristics of a leading comprehensive online video service, namely Youku, in cellular network. This paper is based on a large-scale data set containing over 17 billion traffic traces, collected from a major cellular network in Northeastern China. We analyze the user behavior from three key aspects: data consumption, service usage, and mobility. We provide an insight into how the mobile video service is utilized by users (especially the heavy users), by measuring the user intensities and various representative behavior features in each analysis aspect, such as active time, replay rate, video category, access location, and residence time. We reveal the patterns of different user behaviors, and discuss the implications for practical application. The findings of this paper can provide direct help for network operators and service providers to improve the network performance and user experience.

Next-generation mobile networks (5G) are defined to provide access in the framework of heterogeneous systems where it is crucial to have “always on” and “everywhere connectivity” capabilities. This is of fundamental importance even in 4G mobile systems, down to 3G and also Wi-Fi and WiMAX. In order to guarantee access to users with handheld devices equipped with multiple radio interfaces, an automated and reconfigurable tool for selecting the best network to be connected with is needed. This should be achieved by avoiding service outages. Current vertical handovers, i.e., switching from a network to another, are essentially based on power received levels and often do not avoid temporary service outages. We propose in this paper a procedure to access mobile networks by sensing multiple performance parameters related to networks available in the considered area. We target at maximizing the probability of accessing the wireless medium despite the technology used. We develop an algorithm, based on dynamic programming, able to select the most suitable network. We present the performance of the proposed algorithm both on the basis of computer simulations and on tests performed in an Arduino-based hardware platform.

Mobile web traffic analytics helps mobile network operators to understand subscriber behaviors and network characteristics. With the increasing prevalence of mobile devices, people are prone to access Internet by mobile devices. Meanwhile, a large amount of applications and services are being moved to the mobile web. These changes have resulted in the elevated complexity of mobile web traffic. Consequently, original web traffic models require an adjustment, and network understanding methods also need to update. In this paper, we proposed a stream algorithm to identify user click requests, and reconstructed user-browser interactions by leveraging Spark Streaming framework. The proposed algorithm was tested by massive real HTTP traffic records, which were captured from a cellular core network by high-performance monitoring devices. A statistical analysis was made on the reconstructed data set, and the overall characteristics of mobile web traffic were presented as well. Finally, major improvements in mobile web traffic models were obtained, and the key factors affecting web performance were found. We believe that our models and findings can be useful for mobile network operators to exhaustively understand the mobile web traffic and effectively analyze subscriber behaviors.

In recent years, several kinds of wireless networks have been widely deployed to enhance mobile communication. In this study, we focus on Taiwan's electronic bus (e-bus) system and how public transit data are communicated. In Taiwan's current system, this type of transit data is provided through specific mobile network operators. Such operations require a huge expenditure every month to pay for the subscription fees for data transmission. Therefore, we design a new network system using digital mobile radio (DMR) and enhanced Wi-Fi to replace the current mobile network operator. Furthermore, we propose a dynamic update strategy to increase the system capacity. In the case of emergencies or disasters, 2G/3G/LTE networks may not be very reliable, and our proposed system could be used during rescue operations. It also has lower costs than using mobile networks. The implementation of the system architecture, the application of DMR, and enhanced Wi-Fi in the proposed system, as well as the dynamic update strategy are described in this paper.

Nowadays, the explosively growing demands for mobile service bring both challenges and opportunities to wireless networks, giving birth to fifth generation (5G) mobile networks. The features and requirements of different services are diverse in 5G. The management and coordination among heterogeneous networks, applications, and user demands need the 5G network to be open and flexible to ensure that network resources are allocated with high efficiency. To fulfill these requirements, wireless network virtualization is used to integrate heterogeneous wireless networks and coordinate network resources. In this article we propose a model of wireless network virtualization consisting of three planes: the data plane, the cognitive plane, and the control plane. A novel control signaling scheme has also been designed to support the proposed model. From the implementation perspective of network virtualization, a hierarchical control scheme based on cell-clustering has been used with dynamically optimized efficiency of resource utilization. Two use cases have been analyzed to demonstrate how the schemes work under the proposed model to improve resource efficiency and the user experience.

Continuous growth in the energy consumption of mobile networks has become a major concern for mobile carriers. Since current mobile networks are dominated by mobile data traffic generated by over-the-top mobile applications, it is crucial for mobile carriers to understand how much network energy is used to deliver these applications. Here, we use real network and application measurements to comprehensively analyze the energy consumption of 12 common mobile applications by breaking down their total energy consumption into data and signaling energy components. The results provide insights into the different proportions of data and signaling energy (due to LTE signaling) for different mobile applications. They show that the energy consumption of a mobile application can vary at different base station cell sites due to different ratios of throughput to physical resource block utilization. We estimate the total monthly energy consumption of all 4G users of a major mobile carrier using conventional mobile services, such as voice and the short messaging service, and two over-the-top applications, i.e. a popular instant messaging application in China and an online video application. The results show that signaling energy consumption may become a major concern for mobile carriers, and that this issue will be exacerbated as the usage of over-the-top applications continues to grow. Energy assessment of mobile applications provides valuable information to enable mobile carriers to improve the energy efficiency of their networks. An energy assessment tool that enables real-time network and service energy monitoring will also assist in developing energy-efficient network policies for diverse applications with different energy consumption profiles. Furthermore, given our signaling energy consumption findings for over-the-top applications, there may be benefits for mobile operators to introduce a surcharge for signaling traffic to mitigate the high signaling energy consumption of some over-the-top mobile applications.

With ever growing mobile Internet and the explosion of its applications, users are experiencing abundant services from different content providers via different network service providers in the heterogeneous network. The information-centric network (ICN) advocates getting rid of the current host-centric network protocol because information dissemination rather than end-to-end communication contributes to the majority of today's network traffic. Furthermore, it is better for network entities to converge as a whole in order to take advantage of open, scalable, and smart traffic transmission. The cloud radio access network is one of the emerging architecture evolutions on the wireless side for easier infrastructure deployment and network management. Therefore, when the information-centric network meets the C-RAN in the Het-Net, it is worthwhile and consequential to integrate ICN protocol with C-RAN architecture to achieve more efficient communication and information management. Moreover, SDN has been recognized as another promising architecture evolution to achieve the flexibility and reconfigurability of dense HetNets; its inherent advantage lies in global uniform control of the wired network. Thus, any of ICN, C-RAN and SDN is the complementary to the others. In this article, we contribute to a fresh proposal for and elaboration of the integration of the ICN, CRAN, and SDN for the HetNet to achieve a win-win situation. The vision of the proposed system is demonstrated, followed by the advantages and challenges. We further present a hybrid system in a large-scale wireless heterogeneous campus network.

In early 2012, the International Telecommunication Union (ITU) under the United Nations initiated a program to develop an International Mobile Telecommunication (IMT) system for 2020 and beyond (IMT-2020), thereby officially kicking off the global race toward a yet to be defined fifth generation (5G) mobile network. Fast forward three years, the vision of this next-generation system is beginning to take shape. A recent ITU-Radiocommunication Standardization Sector (ITU-R) Draft Recommendation [1] on IMT-2020 identifies three key usage scenarios in 5G as enhanced mobile broadband, massive machine-type communications, and ultra-reliable and low-latency communications. The same report also issues guidance on the requirements for these scenarios in terms of performance index such as spectrum efficiency, latency, connection density, and area traffic capacity, as shown in Fig. 1. In order to meet these requirements and bring this visionary system to reality, we believe that the future 5G network will be one that is built on a small cell backbone. As spectrum suitable for mobile communication becomes more and more scarce, densification is the only way to meet the area traffic capacity demand. Even for millimeter-wave band, where spectrum is abundant, the channel’s propagation characteristics will likely limit its range for mobile access to that of a small cell, at least in the early phase of 5G before device technology matures. The small cell also brings the radio access point closer to the end device, thereby shortening the last and most challenging segment of an end-to-end communication link, consequently reducing latency and increasing reliability. Many of the massive number of machine-type communications can also benefit from the extended battery life resulting from shorter uplink distance. To facilitate the deployment of a future mobile network that has the small cell as its primary traffic bearing workhorse,the current radio access architecture needs to undergo some major revamping, and new technologies need to be introduced.

In this paper we present an advanced QoS provisioning module with vertical multi-homing framework for future fifth generation (5G) mobile terminals with radio network aggregation capability and traffic load sharing in heterogeneous mobile and wireless environments. The proposed 5G mobile terminal framework is leading to high performance utility networks with high QoS provisioning for any given multimedia service, higher bandwidth utilization and multi-RAT capabilities. It is using vertical multi-homing and virtual QoS routing algorithms within the mobile terminal, that is able to handle simultaneously multiple radio network connections via multiple wireless and mobile network interfaces. Our 5G proposal is user-centric, targeted to always-on connectivity, maximal network utilization, maximal throughput, seamless handovers and performances improvement by using vertical multi-homing, as well as session continuity. The performance of our proposed mobile terminal framework for 5G is evaluated using simulations and analysis with multimedia traffic in heterogeneous mobile and wireless scenarios with coexistence of multiple radio access technologies, such as 3G, 4G as well as future 5G radio access networks.

Scalable and diagnosable are the two most crucial needs for voice call quality assessment in mobile networks. However, while these two requirements are widely accepted by mobile carriers, they do not receive enough attention during the development. Current related research mainly focuses on audio feature analysis, which is costly, sensitive to language and tones, and infeasible to be applied to large-scale mobile networks. In this paper, we revisit this problem, and for the first time explore wireless network , the causal factor that directly impacts the mobile voice quality but yet lacks attention for decades. We design CrowdMi, a wireless analytical tool that model the mobile voice quality by crowdsourcing and mining the network indicators of cellphones. CrowdMi mines hundreds of network indicators to build a causal relationship between voice quality and network conditions, and carefully calibrates the model according to the widely accepted perceptual objective listening quality assessment (POLQA) voice assessment standard. We implement a light-load CrowdMi Client App in Android smartphones, which automatically collects data through user crowdsourcing and outputs to the CrowdMi Server in our data center that runs the mining algorithm. We conduct a pilot trial in VoLTE network in different geographical areas and network coverages. The trial shows that the CrowdMi does not require any additional hardware or human effort, and has very high model accuracy and strong diagnosability.

In this study, based on the concept of a mobile network computer, the author points out that a modern mobile communication network should be referred to as a mobile computer network and a modern mobile communication terminal should be referred to as a "mobile network computer", rather than a "mobile phone" or a "mobile computer" etc. Also, an introduction to the integration approach of mobile communication and computer networks is provided, including technology integration, business integration, network integration, and IMS technology in terms of several aspects, for the purpose of providing people with opportunity to learn more about mobile computer networks, and thereby better understand the concept of a mobile network computer, in order to popularize the concept of mobile network computers throughout the world. In the computer and internet age, network and mobile network computers may be the main terminals of fixed and mobile networks. Therefore, the author of this study not only illuminates the development of mobile network computers, but also draws the outline of a complete picture of the information society in terms of network and mobile network computers. Doing so enables people to have a clearer understanding of information society. It should be noted that in this study both the "mobile network computer" and "mobile computer network" are discussed. These are two distinct types of concepts, so please pay careful attention to avoid confusion.

3GPP has been developing LTE-A standard to significantly enhance the performance of cellular networks by utilizing various radio access techniques to provide ubiquitous and seamless broadband access to a rich diversity of mobile connected devices, which usually demand high QoE in spite of of access location or time. Consequently, it imposes unprecedented stringent requirements on centralized network management at the operator side, which has to overcome formidable complexity in designing, managing, and configuring network architectures, protocols, and algorithms before being able to fully support all LTE-A techniques. It is noticed that the software defined wireless network concept appears to be a promising direction to address such complexity, by decoupling control logic from all network elements and then providing fine-grained control and measurement in LTE-A networks. Toward this end, we propose in this article a device-to-device communication-based algorithm to enhance the QoE of users in software defined multi-tier LTE-A networks. Besides discussing research issues that deserve further study, we also present numerical results to illustrate the performance gains that can be achieved by applying the proposed algorithm to a typical 3GPP network scenario.

A software defined network (SDN) enabled mobile access network is a future network with great potential to support scalable and flexible network applications. To support various network applications, the SDN-enabled mobile access network usually uses forwarding rules in SDN devices. With a limited rule space in existing SDN devices, a rule caching mechanism is an efficient way to improve the network performance. In this paper, we propose SRCMN, which is a new caching structure to improve the network performance with a limited rule space in the SDN-enabled mobile access network. We design a twolayer rule space in each SDN device, which is managed by the SDN controller. We also design a cache prefetching mechanism with the consideration of user mobility. By conducting extensive simulations, we demonstrate that our proposed structure and mechanism significantly outperform original rule space management under various network settings.

This article first analyzes the requirements and challenges in the future 5G mobile wireless network. Then the authors describe a new method for radio access technologies called virtual RATs. The proposed scheme can provide a flexible and tailored access network that can meet the requirements and overcome the challenges in mobile broadband networks. The authors also present a high level design of the overall architecture and protocol stack for virtual RATs. Two concepts, virtual RAT Types and interface sets, are introduced. Two essential features, flexible control/user (C/U) plane separation and coordination between virtual RATs, are also discussed. Examples are provided to show how to achieve a flexible and tailored access network for services by using virtual RATs. Finally, the capability of hardware to support implementation of virtual RATs is analyzed.

Due to the rapid growth of network traffic and new demands from mobile users, the current mobile social networks face challenges in dealing with a huge amount of content requests, high operating costs, and mobility control. How to design mobile social networks efficiently for the upcoming 5G era has become an important issue. In this article we propose and outline a framework of content centric mobile social networks for 5G. First, we present a content centric based network architecture consisting of mobile users, communities, content centric nodes, small cells, and macro cells. Next, we discuss the detailed process to deliver mobile content based on the interests of content and mobile users. In addition, a novel caching scheme is presented to store replicas of mobile content, and the related experiment results are also given.

In order to deal with the challenges and opportunities presented by the mobile Internet, this paper proposes a new Internet-oriented mobile network architecture, dubbed i-Net, for fifth generation (5G) mobile communication systems. Based on direct communications established between the base stations (BSs), i-Net can implement local data routing for mobile data traffic, which adapts to increased service localization for the mobile Internet. We first present the network architecture and main technical features, i.e., inter-connection, integration, and intelligence. Then the key techniques are discussed to show their potential in improving the network efficiency of i-Net. Field trials for inter-BS direct communications to implement cooperative multipoint oPeration (CoMP) in i-Net are carried out to demonstrate the feasibility of i-Net. It is expected that i-Net can provide a good quality of experience for end users through the efficient integration of the multi-BS, multi-band, and multi-radio-access-technology (RAT) radio resources in 5G.

The rapidly diversified market demands have presented a huge challenge to the conventional mobile broadband network architecture. On one hand, the limited machine room space and insufficient power supply make it impossible to accommodate exponentially growing amount of network equipment of operators. On the other hand, net heterogeneity caused by different specifications of wireless access equipment causes costly trouble related to management and optimization. This article, correspondingly, proposes a holistic solution involving different technologies, i.e. network function virtualization (NFV), software defined radio (SDR), and software defined network (SDN). In particular, we investigate both existing standards and possible extensions for 4G/5G mobile networks, followed by a few open issues for future research.

To meet the ever increasing mobile data traffic demand, the mobile operators are deploying a heterogeneous network with multiple access technologies and more and more base stations to increase the network coverage and capacity. However, the base stations are isolated from each other, so different types of radio resources and hardware resources cannot be shared and allocated within the overall network in a cooperative way. The mobile operators are thus facing increasing network operational expenses and a high system power consumption. In this paper, a centralized radio access network architecture, referred to as the super base station (super BS), is proposed, as a possible solution for an energy-efficient fifth-generation (5G) mobile system. The super base station decouples the logical functions and physical entities of traditional base stations, so different types of system resources can be horizontally shared and statistically multiplexed among all the virtual base stations throughout the entire system. The system framework and main functionalities of the super BS are described. Some key technologies for system implementation, i.e., the resource pooling, real-time virtualization, adaptive hardware resource allocation are also highlighted.

This article presents the design and implementation of a dynamic mobile sensor network platform consisting of stationary sensors, mobile sensors, mobile sensor gateways, and sink servers. The sensor network platform supports heterogeneous protocols in the network layer and performs ID-based communications to deliver sensor data from the sensors to the sinks, as well as to send control and monitoring commands from the sensor owner or administrator to the mobile sensors and mobile sensor gateways. To provide sensor data reliably irrespective of the sensor locations, the mobile sensors and mobile sensor gateways natively support mobility and multihoming and possess network access authentication and data transport security functions. The sensor owners can freely install new applications over already-deployed mobile sensors and mobile sensor gateways. They can configure the mobile sensors to operate in lightweight or full-function modes depending on the sensor application requirements or available networking environments. The technical feasibility of the proposed mobile sensor network platform has been demonstrated by implementing a prototype system.

Mobile cloud computing and other new emerging communication paradigms such as mobile social networking and Internet-of-Things, have brought challenges in flexibility, efficiency, and scalability to the current LTE network. Inspired by thinking of the fundamental mechanisms in LTE as reasons causing those problems, SoftNet, a software defined decentralized mobile network architecture toward 5G, is proposed in this article following principles proposed for designing an efficient and scalable network. The analysis of the working mechanisms of SoftNet, including its dynamically defined architecture, decentralized mobility management, distributed data forwarding, and multi-RATs coordination, show that SoftNet has improved system capacity and performance. Further, simulations are conducted to demonstrate that signaling cost in SoftNet, as an important performance metric, can be decreased significantly compared with LTE networks.

With approx. 6 million macro cells worldwide and a gross energy consumption of approx. 100 TWh per year as of 2013, mobile networks are one of the major energy consumers in the ICT sector. As trends, such as cloud-based services and other traffic-intensive mobile applications, fuel the growth of mobile traffic demands, operators of mobile telephony networks are forced to continuously extend the capacity of the existing infrastructure by both implementing new technologies as well as by installing new cell towers to provide more bandwidth for mobile users and improve the network's coverage. In order to implement energy-efficient reconfiguration mechanisms in mobile telephony networks as proposed by the project Communicate Green, it is essential to anticipate traffic hotspots, so that a network's configuration can be adjusted in time accordingly. Hence, predicting the movement of mobile users on a cellular level of the mobile network is a crucial task. In this paper, we propose a Movement Prediction System based on the algorithm of Yavas et al. that allows to determine the future movement of a user on a cellular level using precomputed movement patterns. We extended the algorithm to be capable of preselecting patterns based on time and contextual data in order to improve prediction accuracy. The performance of the algorithm is evaluated based on real and live user movement data from the OpenMobileNetwork, which is a platform providing estimated mobile network topology data. We found that the algorithm's prediction quality is sufficient, but requires an extensive amount of recorded user movements to perform well.

To guarantee the ubiquitous and fully autonomous Internet connections in our daily life, the new technical challenges of mobile communications lie on the efficient utilization of resource and social information. To facilitate the innovation of the fifth generation (5G) networks, the cloud radio access network (RAN) and fog network have been proposed to respond newly emerging traffic demands. The cloud RAN functions more toward centralized resource management to achieve optimal transmissions. The fog network takes advantage of social information and edge computing to efficiently alleviate the end-to-end latency. In this paper, we conduct a comprehensive survey of these two network structures, and then investigate possible harmonization to integrate both for the diverse needs of 5G mobile communications. We analytically study the harmonization of cloud RAN and fog network from various points of view, including the cache of Internet contents, mobility management, and radio access control. The performance of transition between the cloud RAN and the fog network has been presented and the subsequent switching strategy has been proposed to ensure engineering flexibility and success.

In the era of mobile Internet, mobile operators are facing pressure on ever-increasing capital expenditures and operating expenses with much less growth of income. Cloud Radio Access Network (C-RAN) is expected to be a candidate of next generation access network techniques that can solve operators' puzzle. In this article, on the basis of a general survey of C-RAN, we present a novel logical structure of C-RAN that consists of a physical plane, a control plane, and a service plane. Compared to traditional architecture, the proposed C-RAN architecture emphasizes the notion of service cloud, service-oriented resource scheduling and management, thus it facilitates the utilization of new communication and computer techniques. With the extensive computation resource offered by the cloud platform, a coordinated user scheduling algorithm and parallel optimum precoding scheme are proposed, which can achieve better performance. The proposed scheme opens another door to design new algorithms matching well with C-RAN architecture, instead of only migrating existing algorithms from traditional architecture to C-RAN.

Big data analytics applied to signaling, traffic, and wireless environment data in mobile communication networks can help realize autonomous network optimization and build big data-based network operation. In this paper, a signaling-based intelligent network optimization scheme is introduced and applied to the current mobile communication networks, such as 4G Long Term Evolution. In 5G era, big data analytics can help mine user and service requirements from the radio access network level, thus allowing a more efficient 5G design and operation. This paper illustrates how it would significantly facilitate local content provision, dynamical network and functionality deployment, user behavior awareness, fine-tuned network operation, and globally optimized energy saving solutions. It is anticipated that the big data-based 5G network design, and the operation will be greener and softer, and better meet the ever increasing user-centric requirements of mobile communication.

Efficient usage of energy in wireless networks represents a major concern in academia and industry, mainly because of environmental, financial, and quality-of-experience considerations. Various solutions have been proposed to enable efficient energy usage in wireless networks, and these approaches are referred to as green wireless communications and networking. In this survey, we mainly focus on energy-efficient techniques in base stations and mobile terminals as they constitute the major sources of energy consumption in wireless access networks, from the operator and user perspectives, respectively. Unlike the existing articles and surveys, we aim to present a unified treatment of green solutions and analytical models for both network operators and mobile users. Such a unified treatment will help in the future to develop green solutions that enable an improved and balanced efficient usage of energy by operators and end users.

The high reliance on the Internet observed recently makes the quests of mobile networks capacity demand and reliability crucial in mobile networks design and management. The next generation mobile networks is anticipated to address the problem of increasing capacity demand by employing various techniques such as Massive MIMO, Heterogeneous Networks (HetNets), and millimeter wave (mm-Wave). Nevertheless, the benefits of the next mobile networks technology can be realized by network operators and end users if proper network design is well investigated. Network equipment failures are likely to occur, thereby, causing a remarkable monetary loss to both network operators and end users. In addition to the reliability problem, proper network design can reduce capital expenditure (CapEx) and operational expenditure (OpEx). In this study, we investigate the problem of mobile networks design for the next generation mobile networks. We consider two nodes namely Optical Network Unit (ONUs) and Base Stations (BSs). The problem is improving network capacity and reliability through adding new BSs to the live network by connecting to the ONU with optimal OpEx subject to CapEx and reliability. We present an Integer Linear Program (ILP) model that addresses the problem. Finally, we present numerical results that show potential benefits of our study.

While 4G is speeding up its steps towards global markets, 5G has initiated its full development to satisfy an increasing demand on mobile data traffic and big data bandwidth. Centralized data processing, collaborative radio, real-time cloud infrastructure and Cloud Radio Access Network (C-RAN), along with their excellent advantages are being sought by more and more operators to meet end-user requirements. As a promising mobile wireless network architecture, compared with traditional RAN, C-RAN has incomparable advantages in terms of low power consumption, reduced Base Station (BS) numbers, and economic capital and operating expenditure. It can also improve network capacity and BS utilization rate. Recently, C-RAN security has aroused special attention and concern. However, the literature still lacks an overall review on it in order to guide current and future research. In this paper, we first overview the architecture, deployment scenarios and special characteristics of C-RAN. We then provide a thorough review on the existing security studies in the field of C-RAN based on its three logic layers and corresponding security threats and attacks. Particularly, we discuss whether the current literature can satisfy the expected security requirements in C-RAN. Based on this, we indicate open research issues and propose future research trends.

In the present era of modern communication network, the importance of mobile technology can't be denied at all. The requirement of high speed internet access through these mobile devices seamlessly has been increased. The growing use of IP devices in the field of mobile network has generated a great demand of network mobility. To fulfill these demands, network mobility architecture has been studied extensively. Network mobility basic support protocol developed by Internet Engineering Task Force based on mobile IPv6 can be deployed using existing mobile infrastructure. In the basic support protocol, the tunnelling overhead increases with the level of nesting of a mobile network. In order to reduce the this overhead, various route optimization protocol have been proposed. However, most of the protocols fail to provide required quality of services in higher level of nesting. In this paper, we propose a new hierarchical attachment process in nested network mobility scenario that explicitly instructs a new mobile network node to attach at a suitable level of nesting for better quality of service. We observe that the newly proposed attachment process improves its hand-off latency in Nested Network Mobility environment.

In this paper, we provide a gap analysis to apply an IP-based distributed mobility management architecture that is standard in IETF to a 3GPP mobile core network. The IP distributed mobility management deployment model is obtained from the five models defined by the IETF DMM WG, and the 3GPP mobile core network is a 4G-based extended architecture and 5G core network study architecture. We conduct the gap analysis to describe the technology that requires current standards-based applicability and extension for technical interoperability between two standardization organizations.

This paper presents an advanced Security QoS provisioning module with vertical multi-homing and multi-streaming framework for 5G mobile terminals with radio network aggregation capability in next generation mobile and wireless broadband networks. The proposed mobile terminal framework is leading to high performance opportunities for multimedia services with high level of QoS provisioning and secure communications. It is using vertical multi-homing and multi-streaming features with IPSec encapsulations within the mobile equipments, which are able to handle simultaneously multiple radio network secure connections and speed up the transfer of the multimedia services by transmitting each object in a separate stream, achieving high level of QoS and security provisioning. Our proposed model is user-centric, targeted to always-on connectivity, maximal network throughput, with ability to provide various multimedia services with high level of security and confidentiality. The performance of the proposed framework is evaluated though simulations and analysis with multimedia traffic in Next Generation Mobile broadband scenarios with coexistence of multiple heterogeneous radio access technologies, such as existing and future (5G) mobile broadband networks.

Being powered by battery and the reliance on expensive cellular data while users are on the move are holding smart mobile devices from being widely used in those long-lasted, computation-intensive, or highly network-reliant usage scenarios. In the meantime, more and more mobile workloads and optimizations now rely on the cloud, such as mobile cloud offloading, cloud-based mobile web optimization, and cloud-based network traffic redundancy reduction. However, it is hard to perform large-scale and personalized support or optimization for mobile workloads without significant computation resource increase on the cloud, as well as higher bandwidth requirement on the networks. We target solving the above two problems by enabling edge-hosed personalized services (EPS for short). The idea of EPS is twofold. One is enabling developer-customizable and power-and-traffic-efficient network communication on the "last-hop" communication between mobile devices and the network edge. The other is distributing cloud services for mobile workloads to network edge, so that they can be done on a personalized basis, while enjoying much lower communication latency to/from mobile devices.