Fourth Generation Wireless Networks Research Articles

Review on Radio Resource Allocation Optimization in LTE/LTE-Advanced using Game Theory

Recently, there has been a growing trend toward ap-plying game theory (GT) to various engineering fields in order to solve optimization problems with different competing entities/con-tributors/players. Researches in the fourth generation (4G) wireless network field also exploited this advanced theory to overcome long term evolution (LTE) challenges such as resource allocation, which is one of the most important research topics. In fact, an efficient de-sign of resource allocation schemes is the key to higher performance. However, the standard does not specify the optimization approach to execute the radio resource management and therefore it was left open for studies. This paper presents a survey of the existing game theory based solution for 4G-LTE radio resource allocation problem and its optimization.

Scalable Virtualization and Offloading-Based Software-Defined Architecture for Heterogeneous Statistical QoS Provisioning Over 5G Multimedia Mobile Wireless Networks

As a crucial step moving towards the next generation of super-fast wireless networks, recently the fifth-generation (5G) mobile wireless networks have received a plethora of research attention and efforts from both the academia and industry. The 5G mobile wireless networks are expected to provision distinct delay-bounded quality of service (QoS) guarantees for a wide range of multimedia services, applications, and users with extremely diverse requirements. However, how to efficiently support multimedia services over 5G wireless networks has imposed many new challenging issues not encountered before in the fourth-generation wireless networks. To overcome these new challenges, we propose a novel network-function virtualization and mobile-traffic offloading based software-defined network (SDN) architecture for heterogeneous statistical QoS provisioning over 5G multimedia mobile wireless networks. Specifically, we develop the novel SDN architecture to scalably virtualize wireless resources and physical infrastructures, based on user’s locations and requests, into three types of virtual wireless networks: virtual networks without offloading, virtual networks with WiFi offloading, and virtual networks with device-to-device offloading. We derive the optimal transmit power allocation schemes to maximize the aggregate effective capacity, overall spectrum efficiency, and other related performances for these three types of virtual wireless networks. We also derive the scalability improvements of our proposed three integrated virtual networks. Finally, we validate and evaluate our developed schemes through numerical analyses, showing significant performance improvements as compared with other existing schemes.

5G Wireless Networks Deployment with Emerging Technologies and Research Challenges

Over the last couple of decades the world has witnessed gradual, yet steady evolution of mobile wireless communications towards second, third and fourth generation wireless networks. Introduction of digital modulations, effective frequency reuse, penetration of packetbased Internet and rapid advancement in physical layer technologies. Currently all IP based 4G Long Term Evolution (LTE/4G) networks have become a part of everyday life. As a result, a set of new, user-oriented mobile multimedia applications, like mobile video conferencing, streaming video, e-healthcare and online gaming are coming up. These new applications are not only satisfying users’ requirements, but also opening up new business horizons for wireless operators to increase their revenue. Fifth generation mobile communications (5G) are expected to accommodate rapidly increasing mobile traffic aiming at the realization of a “Hyper Connected World” in which all people and surrounding things are connected and information is exchanged between them, and to play the role of a basis of the Internet of everything. The 5G wireless network is expected to become a “Heterogeneous Network” where new wireless access technologies incompatible with 4G and the wireless access technologies for unlicensed band are incorporated with the enhanced technology of 4G (e.g. IMT-advanced). This paper introduces the vision and emerging technology trends of 5G, shows key directions of the research challenges and development of 5G in the future.

Integration of Mobile Ad Hoc Networks in 4G Networks

This Fourth-generation wireless networks may require an integration of mobile ad hoc networks (MANET) into external network to enhance the flexibility of the communication and roaming. This phenomenon is well-suited for commercial and military applications which yield additional benefit of roaming. However, integration of MANET with external network poses a serious security challenge for communication because of open and distributed nature of the ad hoc network.This paper discusses about the 4 G network architecture,its challenges and finally the use of MANET in 4G networks..

Extended Vertical Handoff Decision in Next Generation Wireless Networks

In the vision of 4G wireless communications, it is requisite to provide seamless mobility support across heterogeneous access networks. The benefit of heterogeneous network is that, devices can connect to different wireless networks without interruption of service while the network is being switched. The problem in heterogeneous environments is that transition between diverse types of access technologies can lead to reduced performance, mainly due to incompatibility problems. Seamless mobility can be achieved by enabling mobile terminals to conduct seamless handovers across diverse access networks, that is, seamlessly transfer and continue their ongoing sessions from one access network to another. One major challenge in cellular/WLAN internetworking is how to take advantage of the wide coverage and almost universal roaming support of cellular networks and the high data rates of WLAN. Many issues should be carefully addressed to achieve seamless interworking, such as mobility management, resource allocation, call admission control, security and billing. The vertical handoff requirements are potential of the network, network cost, handoff latency, network conditions, power consumption and user's preference. These must be considered during vertical handoff. In this research paper a new vertical handoff decision based on ARM & AI Techniques is designed. A refined, intelligent Associative Rule Mining (ARM) and Artificial Intelligence (AI) based technique is used to execute the vertical handoff intelligent mechanism in fourth generation wireless networks to produce an effective service which reduces the handoff delay and complexity.

Location-Information-Assisted Joint Spectrum Sensing and Power Allocation for Cognitive Radio Networks With Primary-User Outage Constraint

Fifth-generation (5G) wireless networks are expected to achieve 1000 times higher capacity compared with fourth-generation wireless networks. Thus, improving the spectrum efficiency (SE) is a crucial problem, which must be considered. Cognitive radio (CR) is considered an effective approach to alleviate the spectrum scarcity problem. In this paper, based on the location information of the primary transmitter (PT) and the CR network, we estimate the distance between the PT and the secondary transmitter (ST) and then propose a joint spectrum sensing and power allocation (JSS-PA) scheme to improve the SE of the CR network. In the JSS-PA scheme, we focus on jointly optimizing the sensing parameters and the transmit power of the secondary user (SU) such that the SE is maximized, whereas the primary user (PU) outage constraint is satisfied. When cooperative spectrum sensing is employed to detect the PU's status, we analyze two cooperative strategies, i.e., soft information fusion (SIF) and hard information fusion (HIF). Under the SIF strategy, the optimization of sensing and power (S-OSP) algorithm is proposed to maximize the SE. Under the HIF strategy, the optimization of thresholds (H-OT) algorithm is proposed, and then, the optimization of sensing and power (H-OSP) algorithm is proposed to find the optimal duration of local sensing, the optimal transmit power of the SU, and the optimal final decision threshold. Finally, we present the simulation results to evaluate the performance of the proposed JSS-PA scheme and discuss the effects of the optimal parameters on different schemes under SIF and HIF strategies.

Detection and Leasing of Joint Space and Spectrum Opportunities by Multiple Secondary Network Operators in Cognitive Radio Systems

The fifth generation (5G) wireless networks are expected to achieve 1000 times higher capacity compared to the fourth generation (4G) wireless networks. This implies that maximizing the spectrum efficiency will be one of the key issues to 5G systems. In this paper we consider the problem of detecting and leasing the joint space and spectrum opportunities by a number of secondary network operators (SNOs) in a cognitive network. With the exploitation of an antenna array equipped at each SNO, the whole space in the view of the array can be sliced by multiple partially overlapped beams for each narrowband channel. We derive the energy detection probability of the primary users (PUs) at a given beam for each narrowband channel and the probabilities of that the PUs are located respectively at each neighboring beam under the condition of the PUs located at the given beam and the given narrowband channel. To maximize the spectrum utility, we propose to model the spectrum leasing market of the cognitive network for the obtained opportunities in the framework of the differential games, such that the spectrum price and demand are controlled by a dynamic system. We then derive the open-loop equilibria of the game. Simulation results confirm the efficacy of the proposed methods.

Efficient Internet Access Framework for Mobile Ad Hoc Networks

The development of the Internet services and applications and the trend in the fourth generation (4G) wireless networks to all-IP networks have led to a growing demand for enabling Mobile Ad hoc NETworks (MANETs) to connect to the Internet and achieving the goal of omnipresence Internet which is accessible anytime and anywhere. However, such integration gives rise to a number of challenges. In this paper, an efficient framework which has considered six main challenges encountered in the MANET---Internet integration is proposed. An adaptive distributed multipath internet gateways discovery protocol is proposed, where the gateways advertise their information dynamically to an adaptive limited number of mobile nodes. For mobile nodes that cannot receive this information, an efficient dynamic routing algorithm for MANETs---Internet integration derived from the ant colony optimization algorithms is proposed. In addition, an improved Quality of Services based gateway selection mechanism providing load-balancing is proposed. The simulation study confirms that the proposed framework is scalable and able to cope with changes on the number and mobility of active sources connecting to the Internet and outperforms other conventional approaches in terms of end-to-end delay, packet delivery ratio while attaining acceptable overhead and fair load distribution among all gateways.

Internet connectivity for mobile ad hoc network: a survey based study

Mobile ad hoc network (MANET) is a collection of wireless mobile nodes forming a temporary network without the aid of any established infrastructure or centralized administration. MANETs have become increasingly significant in recent years due to their potential applications. From a technological point of view, the realization of this vision still requires a large number of challenges to be solved related to devices, protocols, applications and services. The drawbacks of MANETs are the limited number of services and applications, limited wireless coverage, limited bandwidth and battery power, and dynamic network topology. The growth of the Internet services and applications and the trend in the fourth generation (4G) wireless networks to all-IP networks have led to an increasing demand for enabling MANET nodes to connect to the Internet and use its services and applications. These kinds of networks are named as hybrid MANETs which can be deployed quickly and easily. The main objective of this paper is to introduce an overview of the different challenges and solutions for MANET---Internet integration. It will also introduce a solid analysis of the most significant proposals by describing their functionality, characteristics, and drawbacks. Summary of features of existing hybrid integration approaches for integration is presented. This survey concludes with further points for investigation.

Three-Dimensional Beamforming: A new enabling technology for 5G wireless networks

It is anticipated that the mobile data traffic will grow 1,000 times higher from 2010 to 2020 with a rate of roughly a factor of two per year. This increasing demand for data in next-generation mobile broadband networks will lead to many challenges for system engineers and service providers. To address these issues and meet the stringent demands in coming years, innovative and practical solutions should be identified that are able to provide higher spectral efficiency, better performance, and broader coverage. Next generations of wireless cellular networks, which are known as fifth generation (5G) or beyond fourth generation (B4G) wireless networks, are expected to produce higher data rates for mobile subscribers in the order of tens of gigabits per second (Gbit/s) and support a wide range of services. Despite the absence of official standards for the 5G, the data rate of 1 Gbit/s per user anywhere for 5G mobile networks is expected to be deployed beyond 2020.

Service Class Resource Management for Green Wireless-Optical Broadband Access Networks (WOBAN)

Exponential growth in the volume of wireless data, boosted by the growing popularity of mobile devices, such as smartphone and tablets, has forced the telecommunication industries to rethink the way networks are currently designed, and to focus on the development of high-capacity mobile broadband networks. In response to this challenge, researchers have been working toward the development of an integrated wireless optical broadband access network. Two major candidate technologies, which are currently known for their high capacity as well as quality of service (QoS) for multimedia traffic, are passive optical networks (PON), and fourth generation (4G) wireless networks. PON is a wired access technology, well known for its cost efficiency and high capacity; whereas 4G is a wireless broadband access technology, which has achieved broad market acceptance because of its ease of deployment, ability to offer mobility, and its cost efficiency. Integration of PON and 4G technologies in the form of wireless-optical broadband access networks, offers advantages, such as extension of networks in rural areas, support for mobile broadband services, and quick deployment of broadband networks. These two technologies however, have different design architectures for handling broadband services that require quality of service. For example, 4G networks use traffic classification for supporting different QoS demands, whereas the PON architecture has no such mechanism to differentiate between types of traffic. These two technologies also differ in their power saving mechanisms. In this paper, we propose a service class mapping for the integrated PON-4G network, which is based on the M/G/1 queuing model. We also propose a class-based power saving mechanism which significantly improves the sleep period for the integrated optical wireless unit, without compromising support for QoS. Results indicate that our proposed class-based power saving scheme reduces power consumption by up to 80%, and maintains the QoS within the requirements of the service level agreement.

An apropos signal report and adaptive period (ASAP) scheme for fast handover in the fourth-generation wireless networks

In this paper, a medium access control (MAC) layer handover scheme is proposed to reduce the handover processing time. Two critical points of investigation are examined to improve the performance of the handover process. The first point is the exact point of time when the handover process should be triggered. This factor is highly related to the signal-to-noise ratio (SNR) the mobile station (MS) receives at that moment. The second point is the moving direction and current moving velocity of the MS. Based on these two factors, an apropos signal report and adaptive period (ASAP) handover scheme is proposed to reduce the handover processing time. ASAP is based on the concept that the received SNR is highly related to the point of time the MS reports and the circumstance the MS stays. If the variation between two reported SNR values is large, the time interval of receiving the next SNR report must be reduced, or increased when the variation is small, to accurately reflect the SNR change. ASAP adjusts the periodic ranging period dynamically according to the MS moving velocity and no additional control messages are introduced into ASAP. ASAP is a base station (BS) initiated handover scheme. Detailed comparisons reveal that ASAP can achieve a handover delay reaching 15ms low at most, which is substantially smaller than the fastest legacy network-assisted handover mechanism (50ms).

SPAWN: a secure privacy-preserving architecture in wireless mobile ad hoc networks

Fourth-generation wireless networks may require an integration of mobile ad hoc networks (MANET) into external network to enhance the flexibility of the communication and roaming. This phenomenon is well-suited for commercial and military applications which yield additional benefit of roaming. However, integration of MANET with external network poses a serious security challenge for communication because of open and distributed nature of the ad hoc network. In this paper, a secure privacy preserving architecture has been proposed to provide privacy and security for data communication in wireless mobile ad hoc networks. This architecture includes the concept of observer obscurity to provide privacy and security for the genuine nodes and to exclude misbehaving nodes in the network. The proposed architecture is designed based on the k-times anonymous authentication and onion routing - a cryptography concept which supports for anonymous communication. The simulation results prove the necessity and effectiveness of the proposed architecture in achieving such privacy and security in the integrated environment.

Unifying identity management for fourth generation wireless networks

The proliferation of fourth generation (4G) networks has motivated the development of new services characterised by ubiquity and convergence. This means that the end-user can access such services from everywhere through the use of multiple networking infrastructures. Despite the benefits resulting from such services, they are intrinsically vulnerable to many spoofing attacks. Thus, a user needs to be identified and authenticated to different serving networks and service providers. The definition of different identities for the same user would be hardly manageable since it would introduce identity confusion and heavy management procedures, especially in the overlapping zones. This study proposes a unique identifer assignment and management techniques in a heterogeneous 4G environment. In this study, the authors introduce a new syntax for the temporal mobile subscriber identity and develop the associated secure identity management process. The proposed scheme, the so-called advanced identity management guarantees mutual authentication, privacy and tracking avoidance, which are of primary importance in 4G networks.

Cross-layer end-to-end label switching protocol for WiMAX–MPLS heterogeneous networks

The integration of WiMAX networks and multi-protocol label switching (MPLS) networks, called WiMPLS networks, is the trend for nomadic Internet access in the fourth generation (4G) wireless networks. The base station (BS) in such heterogeneous networks will play the role of bridge and router between the IEEE 802.16 subscriber stations (SSs) and MPLS networks. However, there is no such integrated solution so far and the switching efficiency of the BS should be considered as well. This paper, therefore, adopts a cross-layer fashion (from network layer to MAC layer) to design the end-to-end label switching protocol (ELSP) for filling this gap. ELSP provides the mechanism of end-to-end (SS-to-SS) and layer 2 switching transfer for switching performance enhancement by assigning the SS with the MPLS labels (M-labels). The M-label can be carried by the IEEE 802.16e extended subheader within the MAC protocol data unit (MPDU), which is fully compliant with the IEEE 802.16e standard. The security issue caused by M-label usage is also concerned and solved in this paper. This paper also reveals an extra advantage that the switching delay of the BS achieved by ELSP can be as low as hardware-accelerated IP lookup mechanism, e.g., ternary content addressable memory (TCAM). Simulation results show that ELSP efficiently improves the end-to-end transfer delay as well as the throughput for WiMPLS heterogeneous networks.

Bilayer Beams and Relay Sharing based OFDMA Cellular Architecture

Over the past decade, researchers have been putting a lot of energy on co-channel interference suppression in the forthcoming fourth generation (4G) wireless networks. Existing approaches to interference suppression are mainly based on signal processing, cooperative communication or coordination techniques. Though good performance has been attained already, a more complex receiver is needed, and there is still room for improvement through other ways. Considering spatial frequency reuse, which provides an easier way to cope with the co-channel interference, this paper proposed a bilayer beams and relay sharing based (BBRS) OFDMA cellular architecture and corresponding frequency planning scheme. The main features of the novel architecture are as follows. Firstly, the base station (BS) uses two beams, one composed of six wide beams providing coverage to mobile stations (MSs) that access to the BS, and the other composed of six narrow beams communicating with fixed relay stations (FRSs). Secondly, in the corresponding frequency planning scheme, soft frequency reuse is considered on all FRSs further. System-level simulation results demonstrate that better coverage performance is obtained and the mean data rate of MSs near the cell edge is improved significantly. The BBRS cellular architecture provides a practical method to interference suppression in 4G networks since a better tradeoff between performance and complexity is achieved.

Trusted Network Selection using SAW and TOPSIS Algorithms for Heterogeneous Wireless Networks

Seamless continuity is the main goal in fourth generation Wireless networks (FGWNs), to achieve this "HANDOVER" technique is used, when a mobile terminal(MT) is in overlapping area for service continuity, Handover mechanism are mainly used. In Heterogeneous wireless networks main challenge is continual connection among the different networks like WiFi, WiMax, WLAN, WPAN etc. In this paper, Vertical handover decision schemes are compared and Multi Attribute Decision Making (MADM) is used to choose the best network from the available Visitor networks (VTs) for the continuous connection by the mobile terminal. In our work we mainly concentrated to the handover decision phase and to reduce the processing delay in the period of handover. MADM algorithms SAW and TOPSIS where compared to reduce the processing delay by using NS2 to evaluate the parameters for processing delay.

Design and Implementation of a Single-Frequency Mesh Network Using OpenAirInterface

OpenAirInterface is an experimental open-source real-time hardware and software platform for experimentation in wireless communications and signal processing. With the help of OpenAirInterface, researchers can demonstrate novel ideas quickly and verify them in a realistic environment. Its current implementation provides a full open-source software modem comprising physical and link layer functionalities for cellular and mesh network topologies. The physical (PHY) layer of the platform targets fourth generation wireless networks and thus uses orthogonal frequency division multiple access (OFDMA) together with multiple-input multiple-output (MIMO) techniques. The current hardware supports 5 MHz bandwidth and two transmit/receive antennas. The media access (MAC) layer of the platform supports an abundant two-way signaling for enabling collaboration, scheduling protocols, as well as traffic and channel measurements. In this paper, we focus on the mesh topology and show how to implement a single-frequency mesh network with OpenAirInterface. The key ingredients to enable such a network are a dual-stream MIMO receiver structure and a distributed network synchronization algorithm. We show how to implement these two algorithms in real-time on the OpenAirInterface platform. Further more, we provide results from field trials and compare them to the simulation results.

Air data systems - integrated multi system wireless networks

Aircraft data networks are fast becoming more of a necessity due to their support for user mobility. Many aircraft manufacturers are planning to deploy data networks within their airplanes and provide internet connectivity to their passengers. While a data network within the aircraft and passenger access to it causes some security concerns, it open up some safety enhancement opportunities. With internet connectivity within the airplane, the activity within the airplane can be monitored in real-time from the ground station. Also, using the high bandwidth satellite links, the flight critical data could be downloaded to a server in the ground station in real-time flight or periodically, thereby enabling real-time flight status monitoring. In a multi-system environment where a mobile node can utilize multiple interfaces and simultaneously connect to multiple providers, new opportunities exist for efficient location management strategies spanning heterogeneous cellular wireless networks. An integrated framework is developed for location management in such a multi-system, fourth generation (4G) wireless networks. This information-theoretic framework allows each individual sub-system to operate fairly independently, and does not require the knowledge of individual sub-network topologies. An efficient location management in such a loosely coupled network is designed by having a mobile node view its movement as a vector-valued sequence, and then transmit this sequence in an entropy coded form to the network. Ill. 2, bibl. 8 (in English; summaries in English, Russian and Lithuanian).

Received Signal Strength-based Cross-layer Designs for Mobile Ad Hoc Networks

In fourth generation (4G) wireless networks and beyond, it is strongly anticipated that mobile ad hoc network will be used to economically extend their coverage and capacity. The mobile ad hoc networks provide new applications, but also face significant technical challenges. Recently, it has been argued that layered architectures are not suitable for wireless networks. In an effort to improve the performance of mobile ad hoc networks, there has been increased interest in protocols that rely on cross-layer interactions between different layers. In this paper, we proposed and studied three cross-layer designs among physical, medium access control and routing (network) layers, using Received Signal Strength (RSS) as cross-layer interaction parameter for energy conservation, unidirectional link rejection and reliable route formation in mobile ad hoc networks. These proposed cross-layer designs are implemented using GloMoSim, the Global Mobile Simulator, and the performance of cross-layer protocol frame work is studied.