Performance Evaluation of VoLTE Based on Field Measurement Data

Voice over Long-Term Evolution (VoLTE) has been witnessing a rapid deployment by network carriers worldwide. During the phases of VoLTE deployments, carriers would typically face challenges in understanding the factors affecting the VoLTE performance and then optimizing it to meet or exceed the performance of the legacy circuit switched (CS) network (i.e., 2G/3G). The main challenge of VoLTE service quality is the LTE network optimization and the performance aspects of the service in different LTE deployment scenarios. In this paper, we present a detailed practical performance analysis of VoLTE based on commercially deployed 3GPP Release-10 LTE networks. The analysis evaluates VoLTE performance in terms of real-time transport protocol (RTP) error rate, RTP jitter and delays, block error rate (BLER) in different radio conditions and VoLTE voice quality in terms of mean opinion score (MOS). In addition, the paper evaluates key VoLTE features such as RObust Header Compression (ROHC) and transmission time interval (TTI) bundling. This paper provides guidelines for best practices of VoLTE deployment as well as practical performance evaluation based on field measurement data from commercial LTE networks

Licensed-Assisted Access to Unlicensed Spectrum in LTE Release 13

Exploiting the unlicensed spectrum is considered by 3GPP as one promising solution to meet the ever-increasing traffic growth. As a result, one major enhancement for LTE in Release 13 has been to enable its operation in the unlicensed spectrum via Licensed-Assisted Access (LAA). In this article, we provide an overview of the Release 13 LAA technology including motivation, use cases, LTE enhancements for enabling the unlicensed band operation, and the coexistence evaluation results contributed by 3GPP participants

Performance and Energy Conservation of 3GPP IFOM Protocol for Dual Connectivity in Heterogeneous LTE-WLAN Network

For the 5th Generation (5G) networks, Third Generation Partnership Project (3GPP) is considering standardization of various solutions for traffic aggregation using licensed and unlicensed spectrum, to meet the rising data demands. IP Flow Mobility (IFOM) is a multi access connectivity solution/protocol standardized by the Internet Engineering Task force (IETF) and 3GPP in Release 10. It enables concurrent access for an User Equipment (UE) to Heterogeneous Networks (HetNets) such as Long Term Evolution (LTE) and IEEE 802.11 Wireless Local Area Network (WLAN). IFOM enabled UEs have multiple interfaces to connect to HetNets. They can have concurrent flows with different traffic types over these networks and can seamlessly switch the flows from one network to the other. In this paper, we focus on two objectives. First is to investigate the performance parameters e.g. throughput, latency, tunnelling overhead, packet loss, energy cost etc. of IFOM enabled UEs (IeUs) in HetNets of LTE and WLAN. We have proposed a novel mechanism to maximize the throughput of IeUs achieving a significant throughput gain with low latency for the IeUs. We have explored further and observed a throughput energy trade off for low data rate flows. To address this, we also propose a smart energy efficient and throughput optimization algorithm for the IeUs, resulting in a substantial reduction in energy cost, while maintaining the high throughput at lower latency and satisfying the Quality of Service (QoS) requirements of the IeUs.Comment: 12 pages, 15 figures, journa

Scalable Application- and User-aware Resource Allocation in Enterprise Networks Using End-host Pacing

Scalable user- and application-aware resource allocation for heterogeneous applications sharing an enterprise network is still an unresolved problem. The main challenges are: (i) How to define user- and application-aware shares of resources? (ii) How to determine an allocation of shares of network resources to applications? (iii) How to allocate the shares per application in heterogeneous networks at scale? In this paper we propose solutions to the three challenges and introduce a system design for enterprise deployment. Defining the necessary resource shares per application is hard, as the intended use case and user's preferences influence the resource demand. Utility functions based on user experience enable a mapping of network resources in terms of throughput and latency budget to a common user-level utility scale. A multi-objective MILP is formulated to solve the throughput- and delay-aware embedding of each utility function for a max-min fairness criteria. The allocation of resources in traditional networks with policing and scheduling cannot distinguish large numbers of classes. We propose a resource allocation system design for enterprise networks based on Software-Defined Networking principles to achieve delay-constrained routing in the network and application pacing at the end-hosts. The system design is evaluated against best effort networks with applications competing for the throughput of a constrained link. The competing applications belong to the five application classes web browsing, file download, remote terminal work, video streaming, and Voice-over-IP. The results show that the proposed methodology improves the minimum and total utility, minimizes packet loss and queuing delay at bottlenecks, establishes fairness in terms of utility between applications, and achieves predictable application performance at high link utilization.Comment: Accepted for publication in ACM Transactions on Modeling and Performance Evaluation of Computing Systems (TOMPECS

Performance Comparison of Packet Scheduling Algorithms for Video Traffic in LTE Cellular Network

In this paper we have studied downlink packet scheduling algorithms proposed for LTE cellular networks. The study emphasize on three most promising scheduling algorithms such as: FLS, EXP rule and LOG rule. The performance of these three algorithms is conducted over video traffic in a vehicular environment using LTE-Sim simulator. The simulation was setup with varying number of users from 10 - 60 in fixed bounded regions of 1 km radius. The main goal this study is to provide results that will help in the design process of packet scheduler for LTE cellular networks, aiming to get better overall performance users. Simulation results show that, the FLS scheme outperforms in terms of average system throughput, average packet delay, PLR; and with a satisfactory level of fairness index

A Simple Reinforcement Learning Mechanism for Resource Allocation in LTE-A Networks with Markov Decision Process and Q-Learning

Resource allocation is still a difficult issue to deal with in wireless networks. The unstable channel condition and traffic demand for Quality of Service (QoS) raise some barriers that interfere with the process. It is significant that an optimal policy takes into account some resources available to each traffic class while considering the spectral efficiency and other related channel issues. Reinforcement learning is a dynamic and effective method to support the accomplishment of resource allocation properly maintaining QoS levels for applications. The technique can track the system state as feedback to enhance the performance of a given task. Herein, it is proposed a simple reinforcement learning mechanism introduced in LTE-A networks and aimed to choose and limit the number of resources allocated for each traffic class, regarding the QoS Class Identifier (QCI), at each Transmission Time Interval (TTI) along the scheduling procedure. The proposed mechanism implements a Markov Decision Process (MDP) solved by the Q-Learning algorithm to find an optimal action-state decision policy. The results obtained from simulation exhibit good performance, especially for the real-time Video application.Comment: 6 pages, 11 figures and 1 tabl

A Survey on QoE-oriented Wireless Resources Scheduling

Future wireless systems are expected to provide a wide range of services to more and more users. Advanced scheduling strategies thus arise not only to perform efficient radio resource management, but also to provide fairness among the users. On the other hand, the users' perceived quality, i.e., Quality of Experience (QoE), is becoming one of the main drivers within the schedulers design. In this context, this paper starts by providing a comprehension of what is QoE and an overview of the evolution of wireless scheduling techniques. Afterwards, a survey on the most recent QoE-based scheduling strategies for wireless systems is presented, highlighting the application/service of the different approaches reported in the literature, as well as the parameters that were taken into account for QoE optimization. Therefore, this paper aims at helping readers interested in learning the basic concepts of QoE-oriented wireless resources scheduling, as well as getting in touch with its current research frontier.Comment: Revised version: updated according to the most recent related literature; added references; corrected typo

Performance of LTE network for VoIP users

With the arrival of LTE standard, it is expected that the mobile voice services paradigm will shift from the circuit switched to fully packet switched mode supporting the VoIP services. VoIP services took quite a bit of time before they were accepted as the main stream telephony service in the fixed networks. To provide VoIP services over the LTE networks with appropriate QoS, it is necessary to analyse the performance of such services and optimise the network parameters. This paper analyses the performance of VoIP services on the LTE network using the FD and the SMP packet scheduling techniques. This work identifies and analyses the features of above LTE packet scheduling techniques to enhance the QoS of VoIP services. An OPNET-based simulation model is used to analyse the performance of VoIP services on the LTE network by incorporating G.711 and G.723 speech coders. The work also studied the performance of VoIP services in variable transmission channel conditions

Delay Estimation and Fast Iterative Scheduling Policies for LTE Uplink

We consider the allocation of spectral and power resources to the mobiles (i.e., user equipment (UE)) in a cell every subframe (1 ms) for the Long Term Evolution (LTE) orthogonal frequency division multiple access (OFDMA) cellular network. To enable scheduling based on packet delays, we design a novel mechanism for inferring the packet delays approximately from the buffer status reports (BSR) transmitted by the UEs; the BSR reports only contain queue length information. We then consider a constrained optimization problem with a concave objective function - schedulers such as those based on utility maximization, maximum weight scheduling, and recent results on iterative scheduling for small queue/delay follow as special cases. In particular, the construction of the non-differentiable objective function based on packet delays is novel. We model constraints on bandwidth, peak transmit power at the UE, and the transmit power spectral density (PSD) at the UE due to fractional power control. When frequency diversity doesn't exist or is not exploited at a fast time-scale, we use subgradient analysis to construct an O(N log L) (per iteration with small number of iterations) algorithm to compute the optimal resource allocation for N users and L points of non-differentiability in the objective function. For a frequency diversity scheduler with M sub-bands, the corre- sponding complexity per iteration is essentially O(N(M^2+L^2)). Unlike previous iterative policies based on delay/queue, in our approach the complexity of scheduling can be reduced when the coherence bandwidth is larger. Through detailed system simulations (based on NGMN and 3GPP evaluation methodology) which model H-ARQ, finite resource grants per sub-frame, deployment, realistic traffic, power limitations, interference, and channel fading, we demonstrate the effectiveness of our schemes for LTE

Modeling and Analysis of Traffic Performance and Coverage of LTE Network with Automatic Cell Planning Method (Lowokwaru Subdistrict, Malang City)

The growth of cellular network technology is very rapid, currently in generation 4 or Long Term Evolution (LTE), namely the development of the third generation. However, there is a problem in this case, namely that there are several cellular networks that are less than optimal considering the very high customer service needs from time to time. The purpose of this study was to improve the quality of performance of several cellular network parameters in the case study area in Lowokwaru District, Malang City. Based on the results that have been carried out by researchers, the results of the average RSRP value before optimization are -100.5 dBm after optimization to -85 dBm, for the average RSRP value before optimization is -10.67 dB after optimization to -6.78, for the SINR value before being optimized 7.6 after being optimized to 29.02 dB. The results value of traffic is 16 user points, the average value per user of downlink data before optimizing is 121 kbps to 128 kbps and the average value of uplink data throughput before optimization is 57.88 kbps 60, 93 kbps. The value of downlink voice throughput before being optimized was 7.16 kbps to 12.2 kbps and the average value of uplink voice throughput before being optimized was 6.43 kbps after being optimized to 12.8 kbps