The Influence of Physical Tuning Technology on Voice Over LTE (VoLTE)

Long-term evolution (LTE) is a broadband wireless communication standard evolved from the Universal Mobile Telecommunications System (UMTS) network. A report from GSA (Global mobile Suppliers Association) said that there are 274 LTE networks have been launched in 101 countries until 2014 Feb [1]. This paper describes the background and current situation of voice over LTE (VoLTE) technology in LTE netwrok. We provide some presentations about existing solutions and operator situation first. And then, we introduce video over LTE technology and elaborate the challenges from voice over LTE to video over LTE.

Nowadays, most communication based train control systems (CBTC) use Wireless Local Networks (WLAN) technology for information transmission. However, because of the high running speed of the train in urban rail transit, WLAN technology cannot fully satisfy the information transmission under the condition of train operation at a high speed. Long term evolution (LTE) technology has a high transmission speed, which can better meet the real-time requirements of train and ground information transmission. Therefore, LTE technology has become an emphasis on the research of communication technology in today’s urban rail transit. Although there is a lot of research on the application of LTE technology in urban rail transit, there is little research on the reliability of LTE based train ground communication systems using experimental data. In this paper, the reliability of train ground communication is firstly defined. Then the train ground communication environment was established in the laboratory, and the performance parameters of train ground communication based on LTE technology were obtained in the test. Finally, the reliability is calculated and analyzed according to the experimental results, and a storage method of train data in actual operation is proposed, which can be used to analyze the reliability of train information transmission. The results show that the reliability of train ground communication based on LTE technology meets CBTC requirements.

This article to analyze and describe the speaking ability of non-English department students, Universitas Riau in the academic year 2016/2017 covering pronunciation, grammar, vocabulary, fluency and comprehension. The study was also aimed to describe the activities done by the English lecturer in the teaching and learning process and the difficulties the students had when speaking. Descriptive qualitative method was used in this study participated by twenty participants at the Faculty of Economics Universitas Riau. The data were gathered using observation, an oral test in the form of interview and documentation. The results of the data analysis of the participants’ speaking ability in terms of pronunciation indicated that 11 participants’ pronunciation was in fair category, 7 participants’ pronunciation was in very good category, 2 participants’ pronunciation was in very good category and none of the participants’ pronunciation was in poor and excellent categories. In terms the participants’ speaking ability in grammar, the findings showed that 12 participants’ grammar was in fair category, 6 was in good category, 2 was in very good category, and none was in poor and excellent categories. In terms of the participants’ speaking ability in vocabulary, it was discovered that 2 participants’ vocabulary was in poor category, 4 was in good category, 14 was in fair category, and none was in very good and excellent categories. The participants’ speaking ability in terms of fluency, the findings revealed that 2 participants’ speaking ability was in poor category, 5 was in good category, 13 was in fair category, and none was in very good and excellent categories. Finally, the participants’ speaking ability in terms of comprehension indicated that 2 participants’ comprehension was in poor category, 4 was in good category, 14 was in fair category, and none was in very good and excellent categories

With the emergence of the Long Term Evolution (LTE) technology, LTE based VoIP services are gaining more and more popularity in these days. Voice over LTE (VoLTE) is a VoIP based multimedia service on All-IP based LTE network, which was initially introduced and commercialized by Korea telecommunication companies in 2012. As more and more subscribers use VoLTE service, the VoLTE traffic volume increases, and this may in turn lower down the VoLTE quality; therefore to preserve QoS of VoLTE service, we need to periodically monitor VoLTE traffic among LTE traffic, and perform appropriate actions to LTE network. To be the first step of realizing this goal, in this paper, we propose a VoLTE traffic classification method and its distributed processing architecture to achieve high throughput. For the classification, we analyze SIP/SDP packets for VoLTE service and generate VoLTE tailored SIP packet signature using SIP User-Agent header field. Since the proposed classification method is relying on Deep Packet Inspection (DPI) method, the classification accuracy can be guaranteed, yet it suffers from the poor processing performance. Therefore, we further propose a distributed and parallel traffic processing architecture with the help of HTCondor.

4G wireless standard, Long Term Evolution (LTE), promises to guarantee delivering of band-consuming applications. In this context data-based services as web browsing with equipped video and video streaming are the most requested services by end user. In order to be able to use all LTE innovative features, Mobile Network Operators (MNO) need to also guarantee both an opportune Quality of Service (QoS) both an acceptable Quality of Experience (QoE) perceived by end user. End-to-end approach for QoS is strongly recommended not only for data-based services but also for delay sensitive services as Voice over LTE (VoLTE). This work presents a method for QoE estimation of a VoLTE service in realistic situations basing on QoS informations. Multiuser and multiservice scenarios are modeled with VoLTE application delivered in conjunction with HTTP web browsing application. An IP cloud is used for modeling network impairments in terms of additive delay and IP packet loss. Simulations are performed using OPNET modeler 17.5. A final comparison of simulation results is provided in order to identity the best mathematical models for QoE estimation for VoLTE application.

Nowadays, the train-ground communication systems of communication based train control systems (CBTC) are based on Wireless Local Networks (WLAN). However, WLAN is not designed for urban rail transit systems. It is susceptible to wireless interference, and high-speed movement environment. Long Term Evolution (LTE) technology is getting popular in train-ground communication systems for its high transmission speed and anti-interference capability. Despite the advantages of LTE technologies, little research has been done to study the reliability of LTE based CBTC train ground communication systems based on experimental data. In this paper, the performance requirements of CBTC train ground communication systems are analyzed according to the principle of CBTC. We define the system reliability based on the packet delay and loss rate performance. The real test environment is set up, and the performance parameters of the train-ground communication are tested. Using the experimental results, we conduct a numerical computation for system reliability. The numerical results show that the reliability of the train-ground communication based on LTE technology satisfies CBTC requirements.

Long Term Evolution (LTE) is a totally IP based cellular network, that only supports packet switching (PS) function, previous cellular networks, such as 2G and 3G, were basically designed to carry voice calls through circuit switching (CS) service, then data service was supported through techniques that basically encapsulated data inside the voice-call connections. In LTE there are many alternatives for offering voice services over LTE to ensure the service continuity over celluar networks, these alternatives include Voice over LTE (VoLTE), also include Over the Top Voice over IP (OTT VoIP) one of the proposed alternatives for voice service over LTE, which is the lowest in cost and complexity. The objective of this paper is, to investigate the quality of the low cost OTT VoIP voice service, as an alternative to VoLTE, especially for those Mobile Network Operators (MNOs), who aren’t ready to deploy the highly complex and costly IP Multimedia Subsystem (IMS) infrastructure of VoLTE . Performance evaluation for OTT VoIP over LTE, compared with VoLTE is provided, from the most important QoS parameters point of view, in different scenarios with different number of users assuming congested and non-congested network states, the analysis for all these scenarios are based on simulations using OPNET 17.5 simulation tool, the results provide a performance template for MNOs who doesn’t want to deploy IMS and doesn’t have legacy 2G/3G networks.

The Recent decades have witnessed intensive efforts from operators to implement methods enabling better control over network utilization, service usage, and service monetization. Nevertheless, they report significant growth in Diameter signaling traffic, especially policy management signaling traffic. More specifically, operators offering long term evolution (LTE) data-only services and planning for a massive introduction of voice over LTE (VoLTE) and voice over WiFi (VoWiFi) services need to tackle the enormous growth in Diameter signaling traffic. The biggest challenge for those operators is to find an appropriate solution, scalable enough to handle the unpredictable growth of Diameter signaling traffic; as the VoLTE and VoWiFi services will reshape the landscape of LTE policies. Throughout this paper, we propose a network function virtualization (NFV) based model, mature enough to tackle the challenges of those operators planning to launch VoLTE and VoWiFi, without impacting existing services and without jeopardizing current revenues. In our approach we first used standard VoLTE and VoWiFi message flow and referenced users' behavior; then we considered NFV architecture characteristics. We finally referred to the latest experiments and test results related to NFV maturity cycle.

The rapid growth of mobile device usage stimulates the application of high-speed mobile broadband services. Thus, the adoption of Long Term Evolution (LTE), the leading standard of the fourth generation (4G) of mobile phone communication technology, becomes the main growth strategy for carriers. However, the LTE network services do not transmit voice data until the Voice over LTE (VoLTE) initiatives. This study applies quality function deployment (QFD) to explore the customer requirements and identify prospective technologies of VoLTE services. Our research shows that the top three important VoLTE techniques are related to "improve efficiency and resource utilization", "enhance the functionality of the handover selection function nodes" and "circuit switched service over a long term evolution network". Furthermore, the study finds that VoLTE outperforms Over-the-top (OTT) services in most of the customer requirements, which assures that VoLTE has its competitive advantage when compares to OTT services in the mobile voice call services.

<span>The increasing demand for telecommunication services causes data traffic density. Therefore, in this research, the long-term evolution (LTE) network expansion was carried out using a choice of frequency bands of 700 MHz, 2100 MHz, and 2300 MHz. The analysis was carried out from the technical and economic aspects. Frequency band recommendations were obtained using the simple multi-attribute rating technique (SMART) method. This research was conducted using a case study of Semarang City. Based on the simulation results, the average of reference signal receive power (RSRP) values for frequency 700 MHz and 2300 MHz is in the very good range, while the frequency of 2100 MHz is in the good range. The signal to interference noise ratio (SINR) values for the three frequencies are in the normal category and the throughput values are in the very good category. The techno-economic calculations of the three frequencies, namely the value of internal rate of return (IRR), net present value (NPV), and payback period are included in the business category that is feasible to do. Based on the ranking results, the 700 MHz frequency is the most superior, both in terms of technical and economic aspects.</span>

The 4G technology, known as Long Term Evolution (LTE), has been dominating the telecommunication market the last years offering a high data rate (up to 100Mbps) that will perfectly satisfy the users multimedia applications needs in term of bandwidth. Designed to be a fully packet switched network, LTE lack in offering the voice CS service. This paper propose an analytical model for simulating the performance of Voice over LTE (VoLTE) while presenting an overview of the latest up to date solutions for the voice over LTE such as Circuit Switched Fall Back, Voice over LTE via Generic Access and third party services for providing call continuity over LTE.

Long Term Evolution (LTE) is expanding its utilization in unlicensed band by deploying LTE Unlicensed (LTE-U) and Licensed Assisted Access LTE (LTE-LAA) technology. Smart Grid can take the advantages of unlicensed bands for achieving two-way communication between smart meters and utility data centers by using LTE-UILTE-LAA. However, both schemes must co-exist with the incumbent Wi-Fi system. In this paper, several co-existence schemes of Wi-Fi and LTE technology is comprehensively reviewed. The challenges of deploying LTE and Wi-Fi in the same band are clearly addressed based on the papers reviewed. Solution procedures and techniques to resolve the challenging issues are discussed in a short manner. The performance of various network architectures such as listen-before-talk (LBT) based LTE, carrier sense multiple access with collision avoidance (CSMA/CA) based Wi-Fi is briefly compared. Finally, an attempt is made to implement these proposed LTE-Wi-Fi models in smart grid technology.

The most effective automatic speech recognition (ASR) approaches are based on artificial neural networks (ANN). ANNs need to be trained with an adequate amount of matched conditioned data. Therefore, performing training adaptation of an ASR model using augmented data of matched condition as the real environment gives better results for real data. Real-world speech recordings can vary in different acoustic aspects depending on the recording channels and environment such as the Long Term Evolution (LTE) channel of mobile telephones, where data are transmitted with voice over LTE (VoLTE) technology, wireless pin mics in a classroom condition, etc. Acquiring data with such variation is costly. Therefore, we propose training ASR models with simulated augmented data and fine-tune them for domain adaptation using deep neural network (DNN)-based simulated data along with re-recorded data. DNN-based feature transformation creates realistic speech features from recordings of clean conditions. In this research, a comparative investigation is performed for different recording channel adaptation methods for real-world speech recognition. The proposed method yields 27.0% character error rate reduction (CERR) for the DNN–hidden Markov model (DNN-HMM) hybrid ASR approach and 36.4% CERR for the end-to-end ASR approach for the target domain of the LTE channel of telephone speech.

Through the introduction of LTE (Long Term Evolution), which is a next-generation radio access network, the traditional circuit switching system in cellular telephony networks is migrating to VoLTE (Voice over LTE). Although LTE can provide high quality and high bandwidth, the call processing capacity of a VoLTE system is designed for normal traffic density, as is the traditional cellular network. However, its performance, measured by the successful call rate, deteriorates when overwhelmed by the large number of calls generated by the special circumstances such as large gatherings and disasters. At such times, users continue to retry calls until the call goes through, resulting in additional degradation of system performance. In this paper, we propose a novel method to improve performance in such circumstances by placing a hold on calls that are likely to fail, and automatically making those calls in IMS (IP Multimedia Subsystem), which is the main call-control function in VoLTE. Finally, we present a simulation of our proposal that demonstrates its effectiveness when users are persistent with their calls.

The current communication solutions train control application that is based on WLAN or GSM-R becomes obsolete with a number of shortcomings in term of capacity and capability. Hence, deploying a new dependability vehicular communication is recommended. In this context, the Long Term Evolution (LTE) technology is considered as a new solution for railway communication because of its ability to support multi-service traffic (voice, video, data). Before widely deploying this new solution in railway industry, it must be evaluated and tested to ensure the desired performance level for train control system (TCS) according to the railway safety standards. In order to overcome the high time execution and low accuracy of statistical evaluation for small probabilities, the analytical treatment is a a complementary approach to the simulation approach. Therefore, it is necessary to propose a new analytical approach for analysing and evaluating the communication error types of the LTE based TCS. It is also the goal of this paper. The results presented in the framework of this paper are prerequisites for the dependability analysis of the advanced TCS based on the LTE technology in further works.