Different Types Of Base Stations Research Articles

A small mobile communication system for communication in remote areas

In the age of the Internet, mobile communications have become an indispensable part of our everyday lives, let us connect with other people, get information, and participate in various activities but the communication in remote areas is still difficult due to terrain constraints and other factors. Although communication in remote areas is very important and challenging, there are also many measures and real cases exist. The article describes a small mobile communication system that can be used in remote areas and analyses its characteristics. First, the coverage area is hexagonal base stations, and I draw the distribution map of base stations and users, and then design a switching criterion to determine when a user changes the service base station during the movement. Second, the distribution is compared with the distribution of different types of base stations to study the difference in their system capacity and the effect of the number of antennas on them. to determine who is more efficient.

Coverage Performance Analysis of a Cache-Enabled UAV Base Station Assisted Cellular Network

Unmanned Aerial Vehicle base stations (UBSs) can be used to assist a ground cellular network to enhance its network services for cellular users. This paper studies the coverage performance analysis of a cache-enabled UBS-assisted cellular network. Analytical models are derived for investigating the overall coverage probability of the network and the average achievable rate of a cellular user. In deriving the analytical models, an air-to-ground (A2G) channel model with both a line-of-sight (LoS) link and a non-line-of-sight (NLoS) link, a BS association strategy based on the strongest average received power, and a cache model with a probabilistic caching strategy are considered. The cache hit probability of UBSs based on the cache model is also taken into consideration. Moreover, the association probabilities with the association strategy are derived for different types of base stations. The derived analytical models are validated through simulation results and the impacts of system parameters on the coverage performance of the network are investigated through numerical results. Compared with existing relevant work, the novelty of this work is that the effects of both an access link and a backhaul link are taken into account in the coverage performance analysis. The obtained results can provide theoretical guidance for the deployment of UBSs in a cache-enabled UBS-assisted cellular network.

A Fairness-based Cell Selection Mechanism for Ultra-Dense Networks (UDNs)

A typical 5G Ultra-Dense Network (UDN) comprises different types of Base Stations (BSs) in its structure. Dense deployment of small-cell BSs within a macrocell BS's coverage offers significant benefits, as the distance between a User Equipment (UE) and its small-cell BS is shorter with robust signals. Thus, the network capacity will increase dramatically. However, selecting an appropriate small-cell BS for a particular UE becomes a challenge in 5G UDNs. This study proposed a mechanism to address the cell selection problem and maximize fairness among UEs when making the cell selection decision. The proposed mechanism considered different parameters. The load balance for each small-cell BS was considered to fairly distribute UEs and avoid traffic congestion. Moreover, the signal strength was considered with the achievable data rate for all small-cell BSs to stimulate idle small-cell BSs to be in operating mode. A simulation was carried out in MATLAB to evaluate the proposed mechanism. Signal-to-Interference-Ratio (SINR) and Signal Strength (SS) -based strategies were also simulated for comparison. The proposed solution outperformed the other schemes in terms of fairness, as the UEs attached to the system were fairly distributed among small-cell BSs. Furthermore, the proposed mechanism achieved the best radio resource distribution in terms of fairness compared to the two other schemes.

Editorial for Wiley's IJSCN Special Issue “Satellite networks integration with 5G”

Editorial for Wiley's IJSCN Special Issue “Satellite networks integration with 5G”

Characterization of base station deployment distribution and coverage in heterogeneous networks

Considering different types of base stations (BSs) in future cellular networks are overlapping deployment with the status of dense, multi-tier and heterogeneous in general, how to optimize the real BS deployment becomes a complicated problem. Based on it, repulsive BS dataset and clustering BS dataset are statically characterized with various types of spatial point processes. It shows that the improvement of coverage probability between 1-tier and 2-tier network fluctuates as the signal-to-interference ratio (SIR) threshold increases for different datasets. The authors' proposed hybrid model fits well with repulsive BS dataset, while the log-Gaussian Cox point process (LGCP) and Cauchy model are reasonable models for clustering BS dataset. Besides, in order to dynamically analyze the coverage problem affected by adding new BSs, a cell boundary constructed by an irregular circle is introduced under an equal SIR constraint, and a BS placement scheme is proposed to place new BSs at the points of minimum interference. Numerical results show that the coverage probability may increase after adding BSs in the target area of heterogeneous network by using the proposed scheme. However, as the density of femto BS reaches a certain value, its coverage may remain unchanged even after adding more femto BSs.

Licensed shared access field trial and a testbed for satellite‐terrestrial communication including research directions for 5G and beyond

SummaryThis paper describes a licensed shared access (LSA) testbed and field trials using a live network. The testbed includes real 4G base stations and up to 1000 virtual base stations, in the spectrum sharing scenario between satellite and cellular systems. The trials focus on 5G pioneer bands 3.4–3.8 GHz and 24.25–27.5 GHz where a satellite system is operating in the downlink direction and a cellular system is accessing the same band. The designed testbed supports both frequency bands. The performance evaluation concerns evacuation and frequency change times using different types of base stations in 3.6 GHz, that is, how fast the system relinquishes the shared band to the primary user and continues transmission using another band. We show that our LSA system is scalable and able to support large number of base stations. In addition, we investigate how satellite systems could reuse International Mobile Telecommunication (IMT) bands to offer enhanced satellite communication services for land, maritime, and aeronautical applications. Preliminary simulations and analysis confirm the possibility to reuse IMT spectrum for satellite systems without causing harmful interference to the terrestrial system.

Performance Analysis of MISINR User Association in 3-D Heterogeneous Cellular Networks

The continuously growing mobile traffic demand is pushing wireless networks to dense heterogeneous architectures with different types of base stations (BSs). In such dense heterogeneous networks (HetNets), especially in the high-rise building 3-D environment, the users need to determine which BS to be associated with before communication. Different user association schemes lead to different system performance. In this paper, a maximum instantaneous signal-to-interference-plus-noise ratio (MISINR) user association scheme is studied in the dense urban environment. A general 3-D model is utilized to model the dense urban HetNets deployed in the high-rise buildings. The coverage probability and average user rate are theoretically derived by using stochastic geometry in a general case and an interference-limited case, respectively. Numerical and simulation results demonstrate that the MISINR user association scheme has the best performance compared with other two association schemes in 3-D HetNets. From the results, it is interesting to observe that the expressions of coverage probability and average user rate can be simplified to closed-forms in the interference-limited case.

CPPHA: Capability-based Privacy-Protection Handover Authentication Mechanism for SDN-based 5G HetNets

Ultra-dense Heterogeneous network (HetNet) technique can significantly improve wireless link quality, spectrum efficiency and system capacity, and satisfy different requirements for coverage in hotspots, which has been viewed as one of the key technologies in fifth Generation (5G) network. Due to the existence of many different types of base stations (BSs) and the complexity of the network topology in the 5G HetNets, there are a lot of new challenges in security and mobility management aspects for this multi-tier 5G architecture including insecure access points and potential frequent handovers among several different types of base stations. In this paper, we integrate user capability and Software Defined Network (SDN) technique, and propose a capability-based privacy protection handover authentication mechanism in SDN-based 5G HetNets. Our proposed scheme can achieve the mutual authentication and key agreement between User Equipments (UEs) and BSs in 5G HetNets at the same time largely reduce the authentication handover cost. We demonstrate that our proposed scheme indeed can provide robust security protection by employing several security analysis methods including the BAN logic and the formal verification tool Scyther. In addition, the performance evaluation results show that our scheme outperforms other existing schemes.

Security Requirement and Standards for 4G and 5G Wireless Systems

In this article, we give an overview on the security requirements and standards for the fourth generation (4G) long term evolution (LTE) and the fifth generation (5G) wireless systems. Compared with the third generation (3G) universal mobile telecommunication system (UMTS), the LTE system not only improves the network capacity and coverage but also provides better performance of data rate, access latency, energy efficiency (EE), and spectrum efficiency (SE) [1]. With the increasing data usage and the new multimedia applications, LTE technologies have been proposed by the 3rd generation partnership project (3GPP) as the broadband mobile wireless networks with packet switched, IP-based technology solely, fully inter-working with different access technologies, different types of base stations and relay nodes. To support more use cases with unique service requirements, 5G wireless systems are developed. There are eight advanced features for 5G wireless systems, 1-10 Gbps connections to end points in the field, 1 millisecond latency, 1000x bandwidth per unit area, 10-100x number of connected devices, 99.999% availability, 100% coverage, 90% reduction of network energy usage and up to ten years battery life for low power devices [2]. These advanced features make 5G wireless systems capable of supporting many new use cases, new industry applications, a multitude of devices and applications to connect society at large. Due to the introduction of new characteristics, there are many new security requirements in the design of the security architectures of the 4G LTE and 5G wireless systems.

Load-Aware Performance Analysis of Cell Center/Edge Users in Random HetNets

For real-time traffic, the link quality and call blocking probability (both derived from coverage probability) are realized to be poor for cell edge users (CEUs) compared to cell center users (CCUs) as the signal reception in the cell center region is better compared to the cell edge region. In heterogeneous networks (HetNets), the uncoordinated channel access by different types of base stations determine the interference statistics that further arbitrates the coverage probability. Thus, the spectrum allocation techniques have major impact on the performance of CCU and CEU. In this paper, the performance of CCUs and CEUs in a random two-tier network is studied for two spectrum allocation techniques namely: 1) co-channel (CSA), and 2) shared (SSA). For performance analysis, the widely accepted conception of modeling the tiers of HetNet using independent homogeneous Poisson point process (PPP) is considered to accommodate the spatial randomness in location of BSs. To incorporate the spatial randomness in the arrival of service and to aid the load-aware analysis, the cellular traffic is modeled using spatio-temporal PPP. Under this scenario, we have developed an analytical framework to evaluate the load-aware performance, including coverage and blocking probabilities, of CCUs and CEUs under both spectrum allocation techniques. Further, we provide insight into achievable area energy efficiency for SSA and CSA. The developed analytical framework is validated through extensive simulations. Next, we demonstrate the impact of traffic load and femto access points density on the performance of CCUs/CEUs under CSA and SSA.

Modeling and Analysis of Downlink Heterogeneous Cellular Networks

Owing to the irregular deployment of different types of base stations (BSs), cellular networks are now becoming more and more complex. In this study, a tractable and accurate framework based on hybrid model is proposed for heterogeneous cellular networks (HCNs). According to the distribution characteristics of different types of BSs in HCNs, the plane distributed macro BSs are termed as tier-1 cells, whereas the small cells, which are spatial distributed, are modeled as tier-2. First, we derive the probability of a target user communicate with macro BS or small cell. Second, we calculate the coverage probability that the target user communicate with macro or small cell respectively. Finally, we obtain the general closed expressions of whole coverage probability. In some special cases, the expressions present simple closed forms and can be calculated easily. Compared with the presented model, the simulation results show that our model is accurate within 1-2dB.

A Novel Architecture for 5G Ultra Dense Heterogeneous Cellular Network

The mounting use of wireless devices and wide range applications in an ultra-dense heterogeneous wireless network has directed to the challenging circumstances that could not be handled till 4G. In order to deal with the critical challenges, the fifth generation (5G) wireless network architecture requires an efficient well-organized wireless network. In this paper, a novel architecture for the 5G ultra-dense heterogeneous cellular network is proposed. In the proposed architecture two main aspects, massive MIMO-OFDMA and IP-based vertical handover are considered. In order to have full network coverage, the whole macro area network is divided into the microcells and each microcell is further divided into the smaller cells. The heterogeneity of different types of base stations (macro area network base station, micro-cell base station, and small cell base station) provides efficient network coverage. By reducing the area of the cell, the frequency efficiency and network coverage are improved. All the base stations are equipped with the massive MIMO-OFDMA antennas and different radio access technologies so a single wireless device can switch from one radio access technology to the other. In order to prevent the link disconnection and save IP address, whenever wireless devices need to perform vertical handover first a new connection is established with new radio access technology. It is important to note the same IP address is used whereas the current connection is disconnected. By utilizing IP-based vertical handover, the new 5G wireless network can become the principal goal of service continuity and minimize the handover processing delay. The simulation results show the improvement in the network performance.

A proxy signature-based handover authentication scheme for LTE wireless networks

A seamless and secure handover is always one of the important design goals of the cellular networks. The handover scheme of 4G Long Term Evolution (LTE) wireless networks is complex due to the presence of two possible different types of base stations. In LTE communication systems, a normal base station is referred to as an eNodeB (eNB). What increases the level of complexity of the system is the fact that the other kind of base stations, namely, Home eNodeB (HeNB), cannot directly communicate with eNB. In the LTE networks, the handover scenarios involving a HeNB could result in a complicated handover procedure. Besides, since key chains have been used in the handover processes, it is found to be lack of backward security. Therefore, in order to handle the handover involving a HeNB efficiently with security provisioning, in this paper, a proxy signature-based handover scheme is proposed. The proposed scheme works based on the Elliptic Curve Cryptography (ECC) algorithm, which makes the computational cost of the handover process smaller compared to other handover schemes.

Small Cell Offloading Through Cooperative Communication in Software-Defined Heterogeneous Networks

To meet the ever-growing demand for a higher communicating rate and better communication quality, more and more small cells are overlaid under the macro base station (MBS) tier, thus forming the heterogeneous networks. Small cells can ease the load pressure of MBS but lack of the guarantee of performance. On the other hand, cooperation draws more and more attention because of the great potential of small cell densification. Some technologies matured in wired network can also be applied to cellular networks, such as Software-defined networking (SDN). SDN helps simplify the structure of multi-tier networks. And it's more reasonable for the SDN controller to implement cell coordination. In this paper, we propose a method to offload users from MBSs through small cell cooperation in heterogeneous networks. Association probability is the main indicator of offloading. By using the tools from stochastic geometry, we then obtain the coverage probabilities when users are associated with different types of base stations (BSs). All the cell association and cooperation are conducted by the SDN controller. Then on this basis, we compare the overall coverage probabilities, achievable rate and energy efficiency with and without cooperation. Numerical results show that small cell cooperation can offload more users from MBS tier. It can also increase the system's coverage performance. As small cells become denser, cooperation can bring more gains to the energy efficiency of the network.

A Semi-Markov Decision Process (SMDP) for Active State Control of A Heterogeneous Network

Due to growing demand on wireless data traffic, a large number of different types of base stations (BSs) have been installed. However, space-time dependent wireless data traffic densities can result in a significant number of idle BSs, which implies the waste of power resources. To deal with this problem, we propose an active state control algorithm based on semi-Markov decision process (SMDP) for a heterogeneous network. A MDP in discrete time domain is formulated from continuous domain with some approximation. Suboptimal on-line learning algorithm with a random policy is proposed to solve the problem. We explicitly include coverage constraint so that active cells can provide the same signal to noise ratio (SNR) coverage with a targeted outage rate. Simulation results verify that the proposed algorithm properly controls the active state depending on traffic densities without increasing the number of handovers excessively while providing average user perceived rate (UPR) in a more power efficient way than a conventional algorithm.

Joint MCS and power allocation for SVC video multicast over heterogeneous cellular networks

Scalable video coding (SVC) and adaptive modulation and coding (AMC) are key issues for video multicast in broadband wireless networks, which could improve users’ received video quality by encoding the video stream into different layers and assigning appropriate modulation and coding schemes (MCSs) to each layer. With the development of mobile communication, various types of cellular networks such as 4G LTE and 3G co-exist at the same place. This type of network is named heterogeneous cellular networks in this paper. Given one ISP usually owns different types of base stations (BSs) at the same place and different BSs may have different traffic loads and transmission capabilities, cooperative transmission among the heterogeneous BSs becomes possible, e.g. a 4G LTE BS could help offload a 3G BS if the 4G LTE BS has extra bandwidth and the devices have the corresponding network interface. As far as the authors understand, how to schedule this cooperation has not been solved in any formal way in literature. This paper presents a joint MCS and power allocation problem in multi-base-station heterogeneous cellular networks for SVC video multicast with the objective to maximize the defined system utility. This problem is NP-hard and in order to solve this, we first decompose this problem into two sub-problems. We present a dynamic programming algorithm to optimize the problem without optimizing the power allocation. Then we take power allocation for each sub-channel into account and propose a multi-base joint dynamic programming and greedy algorithm (MDPGA) algorithm for this joint power and MCS allocation problem in heterogeneous cellular networks. Simulation results show that our algorithms can outperform other competing schemes significantly.

Multilevel power modeling of base station and its ICs

A new power estimation method is proposed for base station (BS) in this paper. Based on this method, a software platform for power estimation is developed. The proposed method models power consumption on different abstraction levels by splitting a typical base station into several basic components at different levels in the view of embedded system design. In particular, our focus is on baseband IC (Integrate Circuit) due to it’s the dominant power consumer in small cells. Baseband power model is based on arithmetic computing costs of selected algorithms. All computing and storage costs are calibrated using algorithm complexity, hardware architecture, activity ratio, silicon technology, and overheads on all hierarchies. Micro architecture and IC technology are considered. The model enables power comparison of different types of base stations configured with different baseband algorithms, micro architectures, and ICs. The model also supports cellular operators in power estimation of different deployment strategies and transmission schemes. The model is verified by comparing power consumption with a real LTE base station. By exposing more configuration freedoms, the platform can be used for power estimation of current and future base stations.

Energy Efficiency Improvements in Heterogeneous Network Through Traffic Load Balancing and Sleep Mode Mechanisms

Heterogeneous network (HetNet) is one of the most promising approaches of IMT Advanced, which not only offers higher capacity and data rate, but also network Energy Efficiency (EE). HetNet is an advanced network that promotes complex cooperation between multiple tiers or sizes of base stations, i.e. macro, micro, pico, and femto base stations towards the above benefits. In this paper, a theoretical model for evaluating the EE of HetNet is proposed. Then, a sleep mode mechanism on picocells is proposed to reduce the total energy consumption which subsequently improves the EE. Simulation results show that EE can be increased by balancing the traffic load between different types of base stations. In fact, the improvement very much depends on the percentage of traffic that is offloaded to picocells. At low to medium traffic load conditions, significant improvements in EE can be observed through the proposed sleep mechanism. It is observed that by combining the sleep mode feature of picocells and load balancing between the different types of base stations in HetNet, further EE improvements up to 68 % for low traffic load and up to 33 % for medium traffic load can be achieved.

Modeling of Energy Efficiency in Heterogeneous Network

Cellular networks are undergoing transformation from conventional homogeneous macro Base Stations (BSs) to Heterogeneous Network (HetNet). This new paradigm not only offers a significant improvement in the overall network capacity or user data rate; it also promises an improvement in the overall network Energy Efficiency (EE). In this study, a theoretical model for evaluating the EE in HetNet is developed. A HetNet generally consists of different types of Base Stations (BSs) which operate in harmony towards a set of common goals defined by the network operator such as coverage and capacity improvement. Each BS may differ in terms of transmit power, achievable data rate, coverage, BS density and EE, under different network deployment scenarios. The results show that the picocell strongly impacts the Energy Efficiency (EE) of the HetNet as compared to microcell. More specifically it is observed that certain ratios of microcells and picocells per macro BS will result in sub-optimal of Area Energy Efficiency (AEE). It is shown that the AEE of HetNet also increases as the percentage area of macro BS overlaid by smaller cells and the density of micro/picocells increases.

An Energy-Aware Protocol for Self-Organizing Heterogeneous LTE Systems

This paper studies the problem of self-organizing heterogeneous LTE systems. We propose a model that jointly considers several important characteristics of heterogeneous LTE system, including the usage of orthogonal frequency division multiple access (OFDMA), the frequency-selective fading for each link, the interference among different links, and the different transmission capabilities of different types of base stations. We also consider the cost of energy by taking into account the power consumption, including that for wireless transmission and that for operation, of base stations and the price of energy. Based on this model, we aim to propose a distributed protocol that improves the spectrum efficiency of the system, which is measured in terms of the weighted proportional fairness among the throughputs of clients, and reduces the cost of energy. We identify that there are several important components involved in this problem. We propose distributed strategies for each of these components. Each of the proposed strategies requires small computational and communicational overheads. Moreover, the interactions between components are also considered in the proposed strategies. Hence, these strategies result in a solution that jointly considers all factors of heterogeneous LTE systems. Simulation results also show that our proposed strategies achieve much better performance than existing ones.