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    A Survey on Security Aspects for LTE and LTE-A Networks

    Jin Cao ; Maode Ma ; Hui Li ; Yueyu Zhang ; Zhenxing Luo
    Communications Surveys & Tutorials, IEEE

    Volume: 16 , Issue: 1
    DOI: 10.1109/SURV.2013.041513.00174
    Publication Year: 2014 , Page(s): 283 - 302

    IEEE Journals & Magazines

    High demands for broadband mobile wireless communications and the emergence of new wireless multimedia applications constitute the motivation to the development of broadband wireless access technologies in recent years. The Long Term Evolution/System Architecture Evolution (LTE/SAE) system has been specified by the Third Generation Partnership Project (3GPP) on the way towards fourth-generation (4G) mobile to ensure 3GPP keeping the dominance of the cellular communication technologies. Through the design and optimization of new radio access techniques and a further evolution of the LTE systems, the 3GPP is developing the future LTE-Advanced (LTE-A) wireless networks as the 4G standard of the 3GPP. Since the 3GPP LTE and LTE-A architecture are designed to support flat Internet Protocol (IP) connectivity and full interworking with heterogeneous wireless access networks, the new unique features bring some new challenges in the design of the security mechanisms. This paper makes a number of contributions to the security aspects of the LTE and LTE-A networks. First, we present an overview of the security functionality of the LTE and LTE-A networks. Second, the security vulnerabilities existing in the architecture and the design of the LTE and LTE-A networks are explored. Third, the existing solutions to these problems are classically reviewed. Finally, we show the potential research issues for the future research works. View full abstract»

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    Toward LTE commercial launch and future plan for LTE enhancements (LTE-Advanced)

    Abeta, S.
    Communication Systems (ICCS), 2010 IEEE International Conference on

    DOI: 10.1109/ICCS.2010.5686367
    Publication Year: 2010 , Page(s): 146 - 150
    Cited by:  Papers (24)

    IEEE Conference Publications

    As a promising radio access technology for next generation mobile communication systems, LTE (Long-Term Evolution) is being standardized by the 3rd Generation Partnership Project (3GPP) international standardization organization. LTE Release 8 has many advantages to the other systems, e.g., the peak throughput is 300Mbps in Downlink (DL) and 75Mbps in Uplink (UL), 2-3 time higher spectrum efficiency than Rel. 6 HSPA (High Speed Packet Access), very low latency around 5msec in RAN (Radio Access Network) and 100msec for connection setup time. With Release 8, the first version for LTE specification, being completed in March 2009, the LTE standard is now being developed towards commercialization in various countries in the world. This paper addresses the plan for LTE commercial launch in NTT DOCOMO and future plan for LTE Rel. 9 and LTE-Advanced (LTE Rel. 10 and beyond). View full abstract»

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    IP Multimedia Relay Architectures with Multi-RAT Support in LTE-Advanced Wireless Network

    Yi-Ting Mai ; Jeng-Yueng Chen
    Modelling Symposium (AMS), 2013 7th Asia

    DOI: 10.1109/AMS.2013.49
    Publication Year: 2013 , Page(s): 283 - 288

    IEEE Conference Publications

    LTE/LTE-Advanced is the competing leader of access network technology in 4G wireless networks. LTE is one of 3GPP standards, and furthermore LTE and LTE-Advanced are developed by 3GPP which are organized by telecommunication manufacturers and operators. Moreover, LTE and LTE-Advanced are backward compatible with 3G/UMTS cellular systems. To improve radio resource utilization, simultaneously deploying Multiple Radio Access Technologies (Multi-RATs) in a given coverage area, to carry the complete offered user traffic, provides a superior user experience. The LTE-Advanced has added a new entity called relay node (RN) to enlarge service coverage and provides flexibility of deployment. If RN can support Multi-RATs including UMTS, IEEE 802.11 and 802.16, the LTE-advanced system can provide more flexible IP multimedia services. However, the virtualization system architecture for Multi-RAT support is still under development. This paper focuses on integrated architecture design by which RN can provide services for both UMTS UEs and LTE UEs. Two novel architectures (Arch-A and Arch-B) with three useful alternatives respectively, namely Alt_1, Alt_2 and Alt_3 are presented in this paper. As shown in the protocol stacks, our proposed approaches can integrate the services of 3G UMTS and 4G LTE-Advanced wireless network. Thus, the transition between 3G and 4G is more easily achieved between our proposed novel Alt_1, Alt_2 and Alt_3 alternatives based on two architectures via IP Multimedia Core Network Subsystem (IMS). View full abstract»

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    Handover algorithm with joint processing in LTE-advanced

    Cheng-Chung Lin ; Sandrasegaran, K. ; Reeves, S.
    Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology (ECTI-CON), 2012 9th International Conference on

    DOI: 10.1109/ECTICon.2012.6254240
    Publication Year: 2012 , Page(s): 1 - 4

    IEEE Conference Publications

    LTE is a purely packet-switched radio access technology and improves the legacy systems by supporting higher data rates with low latency. Release 8 of LTE has a number of gaps that prevent it from meeting the IMT-Advanced requirements for 4G. Release 10 has been proposed to fulfill the additional requirements. Coordinated multipoint (CoMP) transmission and reception is the key technique in LTE-Advanced to improve the cell-edge throughput and/or system throughput, especially joint processing (JP) in CoMP provides multiple data transmission points among multiple cooperated cells for each user equipment (UE) in the network. The standard handover algorithm in LTE could not satisfy the concept of JP in LTE-Advanced. Therefore a new handover algorithm supports JP in LTE-Advanced is necessary. In this paper, a handover algorithm with JP in LTE-A system is implemented and simulated by a C/C++ simulation tool. Simulation results show that, when compared with the standard handover algorithm in LTE system, handover algorithm with JP in LTE-Advanced is able to improve system throughput and minimize packet loss ratio (PLR) effectively. However this algorithm could lead to system capacity overload and saturated system throughput issues when dealing large amount of UEs in the network. View full abstract»

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    Performance of LTE Release 8 and Release 10 in wireless communications

    Abdullah, M.F.L. ; Yonis, A.Z.
    Cyber Security, Cyber Warfare and Digital Forensic (CyberSec), 2012 International Conference on

    DOI: 10.1109/CyberSec.2012.6246127
    Publication Year: 2012 , Page(s): 236 - 241

    IEEE Conference Publications

    LTE-Advanced (Release 10) is a preliminary mobile communication standard formally submitted as a candidate 4G systems to the ITU-T. It is being standardized by the 3rd Generation Partnership Project (3GPP) as a major enhancement of the 3GPP Long Term Evolution (LTE-Release 8) standard, which proved to be sufficient to satisfy market's demand. The 3GPP group has been working on different aspects to improve LTE performance, where the purpose of the framework provided by LTE-Advanced, includes higher order MIMO, carrier aggregation (carriers with multiple components), and heterogeneous networks (relays, picos). This paper presents a study on evolution LTE toward LTE-Advanced in terms of LTE enabling technologies (Orthogonal Frequency Division Multiplexing (OFDM) and Multiple-Input Multiple-Output (MIMO)). This paper also focuses on LTE-Advanced technologies MIMO enhancements for LTE-Advanced, Coordinated Multi Point transmission (CoMP), repeaters and relays. View full abstract»

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    A Survey of Radio Resource Management for Spectrum Aggregation in LTE-Advanced

    Haeyoung Lee ; Vahid, S. ; Moessner, K.
    Communications Surveys & Tutorials, IEEE

    Volume: 16 , Issue: 2
    DOI: 10.1109/SURV.2013.101813.00275
    Publication Year: 2014 , Page(s): 745 - 760

    IEEE Journals & Magazines

    In order to satisfy the requirements of future IMT-Advanced mobile systems, the concept of spectrum aggregation is introduced by 3GPP in its new LTE-Advanced (LTE Rel. 10) standards. While spectrum aggregation allows aggregation of carrier components (CCs) dispersed within and across different bands (intra/inter-band) as well as combination of CCs having different bandwidths, spectrum aggregation is expected to provide a powerful boost to the user throughput in LTE-Advanced (LTE-A). However, introduction of spectrum aggregation or carrier aggregation (CA) as referred to in LTE Rel. 10, has required some changes from the baseline LTE Rel. 8 although each CC in LTE-A remains backward compatible with LTE Rel. 8. This article provides a review of spectrum aggregation techniques, followed by requirements on radio resource management (RRM) functionality in support of CA. On-going research on the different RRM aspects and algorithms to support CA in LTE-Advanced are surveyed. Technical challenges for future research on aggregation in LTE-Advanced systems are also outlined. View full abstract»

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    Open-LTE: An Open LTE simulator for mobile video streaming

    QingHua Zheng ; Haipeng Du ; Junke Li ; Weizhan Zhang ; Qingyu Li
    Multimedia and Expo Workshops (ICMEW), 2014 IEEE International Conference on

    DOI: 10.1109/ICMEW.2014.6890630
    Publication Year: 2014 , Page(s): 1 - 2

    IEEE Conference Publications

    Simulation is the optimal means to evaluate the booming researches on how to enhance the end-to-end service reliability of mobile video streaming over LTE network. However, to the best of our knowledge, all existing LTE network simulators provide simulations of relatively closed virtual networks, in which only meaningless tracing data can be simulated being delivered. Researches on mobile video streaming have not yet been fully supported. In light of this, herein, the open LTE simulator Open-Sim is made to provide the simulation of virtual LTE network with the ability to connect actual hosts over real wired link in realtime. The transport and application layer related logics of video streaming can be deployed on remote hosts and will no longer be limited by the simulator framework. Open-LTE is thus compatible with experimental studies on most aspects of mobile video streaming. Open-LTE is simple to use by providing a centralized configuration file to set up the LTE channel fading scenarios and interconnect real traffic with the virtual LTE network. We will demonstrate our work with QoE experiments on a live video streaming application. View full abstract»

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    Equivalent capacity analysis of LTE-Advanced systems with carrier aggregation

    Ran Zhang ; Zhongming Zheng ; Miao Wang ; Xuemin Shen ; Liang-Liang Xie
    Communications (ICC), 2013 IEEE International Conference on

    DOI: 10.1109/ICC.2013.6655582
    Publication Year: 2013 , Page(s): 6118 - 6122

    IEEE Conference Publications

    The Long Term Evolution - Advanced (LTE-A) standard is widely accepted for the 4th generation mobile systems to satisfy the explosive growth of high-data-rate demand. Carrier Aggregation (CA) is considered as one of the most momentous techniques adopted in LTE-A standard. Many studies have been done to analyze the performance of LTE-A systems with CA in terms of average user throughput. However, the system-level capacity analysis of LTE-A systems has not been well studied. In this paper, we explore the downlink admission control process in LTE-A systems with CA to compare the capacities between LTE users and LTE-A users, based on the metric - equivalent capacity. Specifically, taking into account the user heterogeneity, the system evolution is modeled as a birth-death process for each user class based on an effective user traffic generation model. A closed-form relationship between the equivalent capacity and system bandwidth is then derived for a single-carrier LTE-A system with the help of binomial-normal approximation. The relationship is further extended to multi-carrier case for both LTE users and LTE-A users. Finally, simulation results are provided to verify our analytical ones, and demonstrate that the equivalent capacity of LTE-A users surpasses that of LTE users significantly. View full abstract»

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    CSI-RS design for virtualized antenna when LTE and LTE-A efficiently coexisting

    Jianming Wu
    Personal Indoor and Mobile Radio Communications (PIMRC), 2012 IEEE 23rd International Symposium on

    DOI: 10.1109/PIMRC.2012.6362696
    Publication Year: 2012 , Page(s): 2073 - 2078
    Cited by:  Papers (1)

    IEEE Conference Publications

    In this paper, we newly design a CSI-RS for virtualized antenna system when LTE and LTE-A are efficiently coexisting in Rel-10 and beyond. To this end, we newly insert a small amount of CSI-RS into the locations which is close to the existing CRS positions for legacy LTE as enough as possible. The newly designed CSI-RS modulated by space time coded signal efficiently works well for LTE-A UE channel estimation when the number of antennas involved in LTE-A system is larger than four which are normally used for LTE system as maximal. In such a legacy system with eight physical transmit antennas, eight antenna ports with eight orthogonal CSI-RSs are exploited for LTE-A system while virtualized four antenna ports are for LTE system. The benefit of the proposed solution is to significantly reduce the CSI-RS overhead, compared to the overhead employed in the existing Rel-10 system. View full abstract»

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    Device power saving mechanisms for low cost MTC over LTE networks

    Jha, S.C. ; Koc, A.T. ; Vannithamby, R.
    Communications Workshops (ICC), 2014 IEEE International Conference on

    DOI: 10.1109/ICCW.2014.6881233
    Publication Year: 2014 , Page(s): 412 - 417

    IEEE Conference Publications

    3GPP has started to investigate feasibility of a low cost machine type communication (LC-MTC) terminal class in LTE networks in Release 12 aiming to be competitive with that of GSM/GPRS terminals targeting the same low-end MTC market with improved coverage. LC-MTC devices are expected to have limited power source. Since LTE technology is relatively more power hungry compared to GSM/GPRS, device power efficiency is one of the crucial requirements for LC-MTC over LTE networks. In this paper, we focus on exploring mechanisms to reduce power consumption for LC-MTC in LTE networks. Most of the current LTE power saving mechanisms are designed and optimized for human-to-human (H2H) communications which are not attractive for LC-MTC as traffic characteristics and service requirements for LC-MTC are expected to be largely different than those of H2H Communications. LC-MTC usually has very infrequent and small traffic burst mostly in UL. Therefore, one possible solution to maximize the power saving is to maximize the time with LTE radio turned off in between the traffic bursts. In this paper, we analyze the impact of turning off LTE radio without moving LC-MTC into Radio Resource Control (RRC) Idle and reducing the RRC Connected tail time (i.e., RRC Inactivity Timer). Our results show that turning LTE radio off after data transmission can achieve upto 95.28% reduction in power consumption compared to that in case of moving device to RRC Idle. Reducing RRC Connected tail time further improves the device power saving. View full abstract»

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    LTE-A uplink antenna solution analysis

    Fang Zhou ; Hua Guo
    Communications and Networking in China (CHINACOM), 2013 8th International ICST Conference on

    DOI: 10.1109/ChinaCom.2013.6694609
    Publication Year: 2013 , Page(s): 296 - 301

    IEEE Conference Publications

    MIMO is basic antenna solution for LTE system comparing to UMTS optional MIMO function, and MIMO can improve LTE cell coverage and frequency usage efficiency. Uplink coverage is very important for LTE system, and MU-MIMO antenna solutions can enhance the LTE uplink coverage and capacity. The paper analyses the relation between different antenna configurations and cell spectral efficiency under uplink MU-MIMO antenna mode for LTE-A system. LTE-advanced supports advanced MIMO antenna techniques such as coordinated multi-point (CoMP).The paper proposes 4Rx CoMP antenna deployment solution for LTE-A intra-eNodeB network and also analyses the impact of the LTE cell throughput by uplink 4Rx CoMP technique. View full abstract»

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    Extending the Battery Life of Smartphones and Tablets: A Practical Approach to Optimizing the LTE Network

    Elnashar, A. ; El-Saidny, M.A.
    Vehicular Technology Magazine, IEEE

    Volume: 9 , Issue: 2
    DOI: 10.1109/MVT.2014.2311571
    Publication Year: 2014 , Page(s): 38 - 49

    IEEE Journals & Magazines

    This article provides a practical approach to optimize the long-term evolution (LTE) network to extend the battery life of LTE devices such as smartphones and tablets. The majority of the commercially deployed LTE networks are optimized for data dongles where the battery consumption is not a major concern. With the introduction of LTE smartphones and tablets and other handheld LTE devices, battery consumption has become a major bottleneck to the end user. In this article, we analyze, evaluate, and validate the key relevant features and parameters that can potentially reduce the battery consumption and, hence, extend the device usage time. The objective of this article is to obtain the optimum parameters setting for relevant LTE features to efficiently deliver non-real-time applications with bursty traffic over the LTE network by providing power savings without perceptibly degrading the user experience. The connected and idle-mode discontinuous reception (DRX) mechanism along with the user inactivity timer (UIT) are assessed and evaluated by means of field testing in a live LTE network to identify the optimal deployment scenario for the most common data applications in a commercially deployed LTE network. View full abstract»

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    Testing of early applied LTE-Advanced technologies on current LTE service to overcome real network problem and to increase data capacity

    Seung-Chul Shin ; Young-Poong Lee
    Advanced Communication Technology (ICACT), 2013 15th International Conference on

    Publication Year: 2013 , Page(s): 275 - 281

    IEEE Conference Publications

    LTE service that has advantage of high data rate and speed is successful launched in the world wide with 57 service provider in 32 countries as of Mar 2012. But data throughput gap between peak data rate and average date rate is more increased than legacy wireless application, and it brings big problem on the current high rate data service. Although LTE supports high peak data rate, its average is 35% lower than peak data rate. But 2G service, GSM/GPRS is almost same rate with peak data rate. So Frequency efficiency is became important factor for high data throughput service. Especially, Korea Service providers, SKT, KT, LGU+, try to apply early engaged LTE-Advanced technologies to increase frequency efficiency and to cover data traffic using complementary wireless application like Carrier-Aggregation, Multi-Frequency band, Heterogeneous Network. First of all, briefly introduce LTE-Advanced technologies and problem of current LTE service and finally, we are finding design and test challenges of early applied LTE-Advanced technologies, Carrier-Aggregation, Multi-standard Radio and Multi-frequency band LTE. View full abstract»

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    Impact of smart grid traffic peak loads on shared LTE network performance

    Markkula, J. ; Haapola, J.
    Communications (ICC), 2013 IEEE International Conference on

    DOI: 10.1109/ICC.2013.6655193
    Publication Year: 2013 , Page(s): 4046 - 4051
    Cited by:  Papers (1)

    IEEE Conference Publications

    The purpose of the paper is to examine if public long term evolution (LTE) network is suitable for smart grid (SG) automatic metering usage, in a suburban scenario, without causing significant hindrance to typical LTE traffic. In addition, the same generalized suburban scenario is evaluated with a hybrid sensor - LTE network where wireless sensor network (WSN) cluster heads are also equipped with LTE remote terminal units (RTUs). The simulation topology is formed as a suburban area that consists of single RTU per apartment/house for SG traffic and an average 3.7 people per habitat, each with their user equipment, using one of the available carriers. Normal SG traffic is generated in both directions, uplink and downlink. The worst-case usage factor is considered as a power outage, where all SG meters in the area of influence simultaneously detect and attempt to report such a failure. Thus, emergency SG traffic is generated simultaneous by all RTUs. To alleviate the problem of the high momentary SG emergency traffic load, two distinct solutions are proposed and simulated. As the first solution, an artificial, up to one-second random delay is introduced in the transmission scheduling of emergency messages. The second solution applies low-power WSNs at the cluster level and cluster heads that contain both 802.15.4 and LTE communication interfaces, i.e., a hybrid sensor-LTE network. The simulation results show that both of the solutions that try to alleviate the high instantaneous traffic loads can reach the quality of service criteria for SG traffic without compromising other public LTE traffic. The deciding factor to use either pure LTE approach or a hybrid sensor-LTE network comes from non-functional requirements of the system. View full abstract»

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    Study of advanced-opportunistic proportionate fairness scheduler for LTE medium access control

    Chaudhuri, S. ; Das, D. ; Bhaskaran, R.
    Internet Multimedia Systems Architecture and Application (IMSAA), 2011 IEEE 5th International Conference on

    DOI: 10.1109/IMSAA.2011.6156352
    Publication Year: 2011 , Page(s): 1 - 6

    IEEE Conference Publications

    Medium Access Control (MAC) scheduler entity forms one of the most important parts of any high speed packet access system like HSDPA or LTE. To the best of our knowledge the LTE MAC schedulers that had been proposed so far constitute of sub-carrier resource scheduling mostly based on single criteria like user throughput, link conditions, buffer constraints or power requirement. The above LTE MAC scheduler algorithms do not take care of user's queue weight calculation taking all the above mentioned parameters into consideration. In this paper, we proposed a novel algorithm to support dynamic queue weight calculation and referred it as Advanced-Opportunistic Proportionate Fairness Scheduler for LTE (A-OPFS-LTE). The A-OPFS-LTE, calculates the queue weight based on multiple parameters like flow control feedback, hybrid automatic repeat request (HARQ) retransmission status, service class type, guaranteed bit rate, access terminal (AT's) channel condition, queue's buffer utilization and later assigns the physical resource block. A-OPFS-LTE was able to schedule 14 uncompressed VoIP calls or 5 streaming type video calls every 1 milli-second scheduling cycle with packet loss less than 2%. Compared with MAC scheduler [10, 11], A-OPFS-LTE scheduler supports 10% cell throughput improvement and 30% more users. View full abstract»

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    Coexistence studies on the interference performance between mobile satellite system and LTE network

    Zhang Meng ; Yu Hai ; Fu Yulin ; Chang Yongyu
    Communications, China

    Volume: 10 , Issue: 7
    DOI: 10.1109/CC.2013.6570794
    Publication Year: 2013 , Page(s): 1 - 11

    IEEE Journals & Magazines

    The interference coexistence performance between the systems of a Long Term Evolution (LTE) network and Mobile Satellite Service (MSS) system, both of which work around the frequency of approximately 2 GHz according to the bandwidth allocation in China, is proposed in this article. The related background of an MSS system and the common terminologies are introduced. Further, the coexistence scenarios of different coverage situations shared by the two systems are discussed. The interference impact of an MSS transmission on an LTE system is evaluated using a specific Monte Carlo method. Finally, simulation results show that although no crucial issues for the coexistence of an LTE downlink and the MSS are observed, the LTE uplink suffers a considerable amount of interference from the MSS transmission. Given the insufficient isolation between LTE and MSS existing networks, and the rapid advance in the field of LTE, problems may emerge in the near future. Further, this article can be of significance in providing reference for frequency spectrum planning in the existing LTE networks. View full abstract»

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    CPRI compression transport for LTE and LTE-A signal in C-RAN

    Bin Guo ; Wei Cao ; An Tao ; Samardzija, D.
    Communications and Networking in China (CHINACOM), 2012 7th International ICST Conference on

    DOI: 10.1109/ChinaCom.2012.6417602
    Publication Year: 2012 , Page(s): 843 - 849
    Cited by:  Papers (1)

    IEEE Conference Publications

    C-RAN is the next-generation clean wireless access network architecture, which is based on centralized processing, the Collaborative Radio and Real-time Cloud Infrastructure. In C-RAN architecture, different access technology (eg.GSM / TD-SCDMA / WCDMA / LTE) can be support on the same hardware platform in baseband pool system; C-RAN can be applied to reduce the consumption of operators. LTE (Long Term Evolution) and LTE-A, which are based on OFDM and MIMO technologies, are regarded as the main wireless access technology in the evolution from 3G to 4G. LTE introduces variety of novel technologies to improve the system performance, especially in C-RAN architecture, such as Multi antennas MIMO, Carrier Aggregation, CoMP. However, C -RAN architecture also brings about lager data transmission in the optical fiber. In this paper a low-latency baseband signal compression algorithm used in ALU is introduced to reduce the data rate. Based on the Characteristics of LTE signal data, the algorithm removal redundancies in the spectral domain firstly, and then the block scaling, which is combined with non-linear (nonuniform) quantizer, is designed to minimize quantization error. This algorithm can effectively reduce the amount of data transferred between BBU and RUU in LTE system, to facilitate the deployment of LTE in the CRan architecture. Simulation analysis is given out in the paper; meanwhile TD-LTE system demo verification is also implemented. The results indicate that the scheme introduced can get good performance under a certain compression rate in the real system. Further research is also in progress. View full abstract»

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    Performance and Analysis on LTE System under Adjacent Channel Interference of Broadcasting System

    Wei Li ; Jiadi Chen ; Hang Long ; Bin Wu
    Computer and Information Technology (CIT), 2012 IEEE 12th International Conference on

    DOI: 10.1109/CIT.2012.75
    Publication Year: 2012 , Page(s): 290 - 294

    IEEE Conference Publications

    In the progress of the standardization of the long term evolution (LTE) system, the interference between the LTE system and other systems is quite important. In China, the LTE system and the broadcasting system may deploy in the same geographical area in adjacent frequency channels around the band of 698 MHz in digital dividend spectrum, which is free up for the conversion from analog TV to digital TV. Therefore, with the deployment of frequency planning, it is urgent to ensure the coexistence between the LTE system and the broadcasting system. This paper is aiming at analyzing the interference from the broadcasting system to the LTE system with different distances between the two systems and different offset distances with Monte Carlo simulations. We calculate the required adjacent channel interference ratio values to achieve 5% throughput loss. Simulation results show that the interference situation of LTE uplink is much more severe than LTE downlink and should be paid more attention. Additionally, it can be improved by locating the broadcasting system transmitter at the LTE system's cell edge. View full abstract»

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    Over-the-air LTE measurements in the reverberation chamber

    Chen, Xiaoming ; Hussain, Ahmed ; Kildal, Per-Simon
    General Assembly and Scientific Symposium (URSI GASS), 2014 XXXIth URSI

    DOI: 10.1109/URSIGASS.2014.6929015
    Publication Year: 2014 , Page(s): 1 - 2

    IEEE Conference Publications

    The 3rd Generation Partnership Project (3GPP) has provided successful reports and specifications for Long Term Evolution (LTE). The LTE system is the so-called 4G system. A major difference between LTE and its 3G predecessor is that orthogonal frequency division multiplexing (OFDM) and multiple-input multiple-output (MIMO) techniques are employed in the LTE system, thanks to which a much higher throughput can be achieved in the LTE system. To evaluate LTE with end-user experience, over-the-air (OTA) testing of the performances of LTE devices is needed. Among the MIMO-OTA testing techniques, the reverberation chamber (RC) based OTA testing system [1, 2] seems the most promising candidate due to its fast and repeatable measurement. Despite the high efficiency of the RC-based OTA measurement, a theoretical model of the OTA measurement to complement measurement is desired. With throughput being the most interesting performance metric of LTE OTA testing, a throughput model based on the threshold receiver concept has been proposed in [3]. The throughput model is valid for both diversity and spatial multiplexing cases [4]. The reverberation chamber was first used for EMC measurements, i.e. measuring the effects of undesired radiation. Then, measurement uncertainty was not important. In this paper we describe how it is used for measuring the effects of desired radiation, and then we of course would like to have measurement uncertainties smaller than 0.5 dB in order to distinguish good from bad LTE devices. This is possible with the latest RC developments [5]. Fig. 1 shows the modeled and measured LTE system with different system bandwidth Bs under different channel coherence bandwidths Bc. Note that the coherence bandwidth in the RC can be controlled by loading the chamber with different amounts of lossy objects [6], whereas, in the simulation, it is taken into account by generating independent OFDM subcarriers [3]. As can be seen, the throughput mode- well predicts the measurement. In the final presentation, we will present the throughput model in details. We will also present LTE throughput measurements and modeling for different LTE MIMO configurations, the relationship between Total Isotropic Sensitivity (TIS) and throughput, and the interpretation of throughput as a Probability of Detection (PoD). View full abstract»

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    BER analysis of single/multi-user LTE and LTE- A systems

    Chawla, P. ; Gupta, B.
    Advance Computing Conference (IACC), 2014 IEEE International

    DOI: 10.1109/IAdCC.2014.6779331
    Publication Year: 2014 , Page(s): 262 - 266

    IEEE Conference Publications

    Multi-input-multi-output (MIMO) systems along with orthogonal frequency division multiplexing (OFDM) technique plays a crucial role in 4G based wireless networks. The inclusion of MIMO technology enables new types of links such as downlink multi-user communication. Long term evolution (LTE) systems are based on multi-user MIMO technologies, which have flexible bandwidths. In this paper, we derived closed form expression of bit error rate (BER) for multi-user LTE and LTE-Advanced (LTE-A) systems. Moment generating function (MGF) and pair-wise error probability (PEP) based approaches are used to derive these BER expressions. Theoretical results of BER are validated using simulation results for different number of users. Results are plotted on the basis of various features such as coordinated multipoint (CoMP) transmission and reception, multimedia broadcast and multicast services (MBMS) and allocation of Bandwidth in LTE and LTE-A systems. View full abstract»

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    Short paper: A LTE-direct broadcast mechanism for periodic vehicular safety communications

    Gallo, L. ; Harri, J.
    Vehicular Networking Conference (VNC), 2013 IEEE

    DOI: 10.1109/VNC.2013.6737604
    Publication Year: 2013 , Page(s): 166 - 169

    IEEE Conference Publications

    LTE-Direct is an upcoming LTE rel. 12 extension to allow UEs to communicate directly without going through an eNB. LTE-Direct is expected to be used in future LTE-A networks for unicast Proximity Services, and has not been envisioned so far for broadcast transmissions. In this paper, we propose an eMBMS-inspired mechanism to allocate LTE-Direct resources for dedicated broadcast/multicast vehicular safety communications. The mechanism does not require any connection procedure for LTE-Direct broadcast transmissions, and proposes to reserve identical LTE downlink resources over multiple eNB for dedicated communications between UEs. We apply this concept to the periodic broadcast of BSM/CAM and illustrate that the mechanism's flexibility and extensibility makes LTE-Direct a good complementary technology to DSRC for periodic vehicular safety communications. View full abstract»

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    Looking at LTE in Practice: A Performance Analysis of the LTE System Based on Field Test Results

    Elnashar, A. ; El-Saidny, M.A.
    Vehicular Technology Magazine, IEEE

    Volume: 8 , Issue: 3
    DOI: 10.1109/MVT.2013.2268334
    Publication Year: 2013 , Page(s): 81 - 92

    IEEE Journals & Magazines

    This article introduces a practical performance analysis of the long-term evolution (LTE) cellular system based on field test results from a commercially deployed Third-Generation Partnership Project's (3GPP?s) Release 8 LTE network in Band-3 (i.e., 1,800 MHz, sometimes termed LTE1,800 MHz) with 20-MHz channel bandwidth. The presented analysis demonstrates the downlink (DL) and uplink (UL) throughputs in mobility conditions in addition to other aspects of the LTE system such as link budget, cell coverage, spectral efficiency, and handover performance. LTE's key features such as multiple-input, multiple-output (MIMO) and higher-order modulation [i.e., 64 quadrature amplitude modulation (QAM)] are assessed in different radio frequency (RF) conditions. A comparison is presented between LTE and 3GPP Release 8 evolution of high-speed packet access (HSPA+) with a dual-cell high-speed DL packet access (DC-HSDPA) feature based on the universal mobile telecommunications system (UMTS) 2,100-MHz commercial network with 10-MHz bandwidth (i.e., 2x5-MHz adjacent carriers). The presented LTE network performance analysis and the comparison with the HSPA+ network can be used to benchmark the LTE system performance and evaluate the gains and merits of deploying the LTE network. It has been demonstrated that the LTE system outperforms the HSPA+ system in terms of spectrum efficiency, 64-QAM utilization, cell coverage, and handover delay. The LTE system offers a 34% improvement in spectrum efficiency, 40% 64-QAM utilization versus 7.4% for the HSPA+ system, and a 60% reduction in data interruption time during handover. View full abstract»

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    A study of LTE network performance based on data analytics and statistical modeling

    Sanqing Hu ; Ye Ouyang ; Yu-Dong Yao ; Fallah, M.H. ; Wenyuan Lu
    Wireless and Optical Communication Conference (WOCC), 2014 23rd

    DOI: 10.1109/WOCC.2014.6839911
    Publication Year: 2014 , Page(s): 1 - 6

    IEEE Conference Publications

    Various simulation based approaches are developed to study wireless network performance and capacity traditionally. However, these simulation based approaches has its own limitations in supervised and unsupervised learning. Since big data techniques become more available, using big data techniques to understood the huge amount of the LTE network measurements and diagnosis data, evaluate and predict the LTE network capacity and performance becomes a very promising approach. This paper investigates the LTE network performance from the aspect of data analytics and statistical modeling. In this paper, we develop a methodology of data analytics and modeling to evaluate LTE network performance based on traffic measurements and service growth trends. A relational algorithm is developed to obtain the relationship between LTE network resources and LTE KPIs and a forecasting algorithm is developed to trend the network resource consumptions based on traffic and service growth. The numerical results show a high accuracy, robustness, and reliability of the proposed methodology. View full abstract»

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    Traffic-Aware Energy Optimization in Green LTE Cellular Systems

    Saxena, N. ; Sahu, B.J.R. ; Young Shin Han
    Communications Letters, IEEE

    Volume: 18 , Issue: 1
    DOI: 10.1109/LCOMM.2013.111213.131809
    Publication Year: 2014 , Page(s): 38 - 41

    IEEE Journals & Magazines

    Commercial deployment of 4G LTE networks and rapid penetration of smart phones have exponentially increased the wireless data traffic, thus increasing the energy consumption and greenhouse (CO2) gas emission. The concept of green 4G LTE networks lies in the development of energy efficient LTE systems for reducing the greenhouse emissions as well as operators' energy bill. In this letter we first identify the complexity of the optimal traffic awareness in LTE networks and subsequently design a cooperative communication framework for traffic-aware energy optimization. The LTE eNBs explore an information theoretic approach to capture the dynamics and uncertainty of network traffic. Subsequently, using an online, stochastic game theoretic algorithm, the eNBs communicate amongst themselves to optimize the traffic awareness. Optimal traffic awareness helps in reducing the network energy consumption. Simulation results demonstrate that our framework results in almost 22% (40 KW-Hr) daily energy savings across a LTE network of 400 cells. View full abstract»

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    Effect of LTE service adoption on mobile data traffic in Korea

    Soyoung Park ; Jeongtae Kim
    Computing and Convergence Technology (ICCCT), 2012 7th International Conference on

    Publication Year: 2012 , Page(s): 1197 - 1200

    IEEE Conference Publications

    After LTE service is launched in many countries, the number of subscribers of LTE service is globally increasing rapidly. Data traffic caused by LTE users is also in a rapid growth, since LTE supports high data rate services such as multimedia applications, web, and data services. Although LTE service contributes to the rapid data traffic increase, the LTE traffic partially substitute for the traffic of traditional mobile communication services such as 2G and 3G. In this paper, we estimate traffic substitution rate of LTE for 3G services in Korea. For that, we first predict the number of subscribers of 3G services assuming that LTE service is not adopted. Then Effect of LTE on subscribers and traffic of traditional mobile services and total mobile traffic in Korea is presented. View full abstract»

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