Downlink Packet Scheduling Research Articles

An improved downlink packet scheduling algorithm for delay sensitive devices in both H2H and M2M communications in LTE-advanced networks

An improved downlink packet scheduling algorithm for delay sensitive devices in both H2H and M2M communications in LTE-advanced networks

Latency-Rate Downlink Packet Scheduler for LTE Networks

The Long-Term Evolution standard is currently the leading technology used in mobile 4G networks. Under LTE user devices may request services available on the Internet such as voice/vid ...

Enhancing the Energy-Efficiency and Timeliness of IoT Communication in WiFi Networks

Increasing the number of Internet of Things (IoT) stations or regular stations escalates downlink channel access contention and queuing delay, which in turn result in higher energy consumption and longer communication delays with IoT stations. To remedy this problem, this paper presents WiFi IoT access point (Wiotap), an enhanced WiFi access point (AP) that implements a downlink packet scheduling mechanism. In addition to assigning higher priority to IoT traffic compared to regular traffic, the scheduling algorithm computes per-packet priorities to arbitrate the contention between the transmission of IoT packets. This algorithm employs a least-laxity first (LLF) scheme that assigns priorities based on the remaining wake-up time of the destination stations. We used simulation to show the scalability of the proposed system. Our results show that Wiotap achieves 37% improvement regarding the duty cycle of IoT stations compared to a regular AP. In addition, we developed a testbed to confirm the implementation correctness and the performance benefits of Wiotap in a network with four IoT stations and regular traffic. For the edge and cloud scenarios, our empirical evaluations show up to 44% and 38% improvement in energy and 52% and 41% improvement in delay, respectively.

A Low-Complexity Scheduler to Improve the Number of Satisfied Video Streaming Users in LTE

The ongoing development of mobile communication networks has led to an expressive growth in capacity demand, mainly due to video streaming services, which together with the Internet of Things sector represent a challenge for the mobile network operators. Video streaming is already responsible for most of the Internet traffic, and the real-time video calling services are becoming increasingly common. The use of strict quality of service parameters can lead to global resource starvation, where no user can be served with the resources available. In case of network congestion is important to prevent global resource starvation problem and also serve as many users as possible with a reasonable quality of service while still ensuring a minimum of connectivity to other users. Considering this problem, this article presents a new channel-aware downlink packet scheduler for Long Term Evolution networks that aims to increase the number of satisfied real-time video streaming users. The performance evaluation was done through computer simulations, using peak signal-to-noise ratio (PSNR) to compare the quality delivered by competing algorithms, and the number of users who are given enough resources to play video with quality. The results indicate that the proposed method outperforms the commonly-used algorithms considering the number of satisfied users and average video PSNR, mainly under moderate-to-heavy traffic load conditions.

Carrier Aggregation based Downlink Packet Scheduling Scheme with Improved Quality of Service

Carrier Aggregation based Downlink Packet Scheduling Scheme with Improved Quality of Service

An improved downlink packet scheduling algorithm for delay sensitive devices in both H2H and M2M communications in LTE-advanced networks

The demand for increased data rate with improved QoS for real-time data traffic is ever increasing in the present day wireless environment. The scheduling schemes available in the literature incur lot of scheduling overhead at the eNodeB. Therefore, this work recommends an energy efficient, QoS-aware scheduler with reduced scheduling complexity at the eNodeB, for transmission of delay sensitive data. The scheduling problem is composed as a gain of weighted transmission rates of all possible combinations of various resources required by the channel for transmitting data. An improved greedy algorithm at the eNodeB, has been developed to allocate the resources dynamically to the user equipments (UEs) for the transmission of real-time data. The input video frames to the algorithm are compressed using discrete wavelet transform. The results of this research work show that the proposed scheduling algorithm greatly improves the coverage of the cell edge users. The performance of this greedy scheduler is compared with other two notable schedulers in the literature namely LOG rule and EXP-rule. This scheduling algorithm outperforms the other schemes in terms of QoS parameters for real-time data transmission.

Adaptive downlink packet scheduling in LTE networks based on queue monitoring

The dynamic packet scheduling is a key component of LTE network to enhance the system throughput, as well as to satisfy the end users with the quality of service. However, the burst in user data traffic leads to user queue overflow at eNodeB due to resource starvation. Therefore, in this paper, queue monitoring and resource scheduling algorithms are proposed for LTE downlink transmission to reduce overflow of the user queue at eNodeB, and also to reduce the transmission time of the packet. On the other hand, this also enhances the system throughput and maintains fairness among the users. The dynamic packet scheduling mechanism first checks the queue level of user at eNodeB, channel condition of the user, resource allocation history and QoS of the packets, and then computes the priority metric of user by using these parameters. Then, using three proposed resources allocation mechanisms, the resource blocks are allocated to the users based on priority metric of user as well as queue status of user at eNodeB. The experimental results illustrate that the proposed algorithms enhance the system throughput compared to other existing schedulers. Further, it also improves packet delivery fraction and reduces the transmission time of the packets.

A Joint Evaluation of Energy-Efficient Downlink Scheduling and Partial CQI Feedback for LTE Video Transmission

A green cellular technology is proposed to optimize the energy and spectrum resources. Such optimization will require perfect channel state information at the transmitting base station. However, reporting the channel status of the entire bandwidth requires huge undesirable feedback overhead. Therefore, the aim of this paper is to optimize the energy and bandwidth resources while maintaining quality-of-service at the downlink when a partial feedback is considered. In this paper, a modified downlink scheduler based on a Packet Prediction Mechanism (PPM) is conducted at the eNodeB to optimize the energy and spectrum resources. On the user equipment side, a partial channel feedback scheme based on an adaptive feedback threshold is developed. A primary concern of this feedback scheme is to reduce the uplink signaling overhead without a substantial loss in downlink performances. Finally, the downlink packet scheduling and the partial feedback are jointly evaluated to further enhance the system performance. Based on a system-level simulation results, the proposed energy-efficient scheduling with partial feedback has achieved an improvement in EE of up to 79% compared to the PPM scheduler. Besides, it minimizes the degradation caused by the partial channel quality indicator feedback. Thus, the proposed two-sided algorithm gives the best tradeoff between uplink and downlink performances.

A novel downlink semi-persistent packet scheduling scheme for VoLTE traffic over heterogeneous wireless networks

Long-term evolution (LTE) is becoming the first choice of mobile network operators (MNOs) when constructing a wireless network infrastructure because of its high data rate, high throughput, and low latency. These significant advancements are necessary for satisfying the delivery of a wide-range of mobile applications and managed network resources. However, deploying a new LTE network or a transition from current legacy cellular networks to LTE can take several years to roll out. In the meantime, working in a heterogeneous wireless communication network looks inevitable. This paper investigates Voice over LTE (VoLTE) Quality of Service (QoS) under a heterogeneous wireless communication scenario. The contributions of this paper are twofold. First, a novel downlink (DL) semi-persistent scheduling scheme is proposed to reduce VoLTE end-to-end delay and increase system capacity. Second, an extensive network simulation model has been designed and implemented to evaluate the proposed scheme. The performance of the proposed scheme is compared with the performance of two relevant and well-known DL packet scheduling methods. The simulation results confirm that the proposed scheme is able to reduce VoLTE end-to-end delay and achieve a better system capacity than current methods, and maintain the desired VoLTE QoS.

Performance evaluation of downlink packet scheduling for real time traffic in LTE system

Long-term evolution (LTE) is one of the promising broadband wireless technologies developed by third generation partnership project (3GPP) to support higher data rate. Packet scheduling is one of the open issues in deciding the overall system performance. In this paper, a new scheduling scheme is proposed that is suitable for real time services. In this method, two metrics are estimated for the packets based on the type of bearers. Tmax is calculated for guaranteed bit rate (GBR) bearers and Tmin is calculated for non-GBR bearers. The main objective is to allocate first all GBR bearers because of their highest quality-of service (QoS) requirements. After the resource allocation of GBR bearers, if the current transit time interval (TTI) has more resources, then the packets of non-GBR bearers are entertained. The proposed scheme is compared with traditional scheduling algorithms and validated by means of simulation results.

Performance evaluation of downlink packet scheduling for real time traffic in LTE system

Long-term evolution (LTE) is one of the promising broadband wireless technologies developed by third generation partnership project (3GPP) to support higher data rate. Packet scheduling is one of the open issues in deciding the overall system performance. In this paper, a new scheduling scheme is proposed that is suitable for real time services. In this method, two metrics are estimated for the packets based on the type of bearers. Tmax is calculated for guaranteed bit rate (GBR) bearers and Tmin is calculated for non-GBR bearers. The main objective is to allocate first all GBR bearers because of their highest quality-of service (QoS) requirements. After the resource allocation of GBR bearers, if the current transit time interval (TTI) has more resources, then the packets of non-GBR bearers are entertained. The proposed scheme is compared with traditional scheduling algorithms and validated by means of simulation results.

A Novel Algorithm for Efficient Downlink Packet Scheduling for Multiple-Component-Carrier Cellular Systems

The simultaneous aggregation of multiple component carriers (CCs) for use by a base station constitutes one of the more promising strategies for providing substantially enhanced bandwidths for packet transmissions in 4th and 5th generation cellular systems. To the best of our knowledge, however, few previous studies have undertaken a thorough investigation of various performance aspects of the use of a simple yet effective packet scheduling algorithm in which multiple CCs are aggregated for transmission in such systems. Consequently, the present study presents an efficient packet scheduling algorithm designed on the basis of the proportional fair criterion for use in multiple-CC systems for downlink transmission. The proposed algorithm includes a focus on providing simultaneous transmission support for both real-time (RT) and non-RT traffic. This algorithm can, when applied with sufficiently efficient designs, provide adequate utilization of spectrum resources for the purposes of transmissions, while also improving energy efficiency to some extent. According to simulation results, the performance of the proposed algorithm in terms of system throughput, mean delay, and fairness constitute substantial improvements over those of an algorithm in which the CCs are used independently instead of being aggregated.

A Pre-Scheduling Mechanism in LTE Handover for Streaming Video

This paper focuses on downlink packet scheduling for streaming video in Long Term Evolution (LTE). As a hard handover is adopted in LTE and has the period of breaking connection, it may cause a low user-perceived video quality. Therefore, we propose a handover prediction mechanism and a pre-scheduling mechanism to dynamically adjust the data rates of transmissions for providing a high quality of service (QoS) for streaming video before new connection establishment. Advantages of our method in comparison to the exponential/proportional fair (EXP/PF) scheme are shown through simulation experiments.

A Review of Downlink Packet Scheduling Algorithms for Real Time Traffic in LTE-Advanced Networks

Objective: In recent times, the demand for high data rates is ever increasing in any wireless network environment. Long Term Evolution-Advanced (LTE-A) is the latest 4G technology which is developed based on 3GPP specifications. Our main objective in this proposed research wok is to analyze the various packet scheduling algorithms for downlink real time data and present their scheduling metrics. Methods: In this review we considered more recent scheduling algorithms which are QoS aware and with specific focus on real time traffic classes such as VoIP, Video Streaming, Interactive Gaming and mobile video conference. Conclusion: Our most significant observation from this review is that any packet scheduling algorithm for downlink real time data should be QoS aware so that it is readily deployable in the present day multimedia networks. The scheduling schemes should also consider the latest technologies such as Carrier Aggregation (CA) and Multi Input and Multi Output (MIMO). Applications: The presented review will help the researchers and academicians to develop more efficient scheduling schemes for real time applications for smart phone users with better quality of experience and efficient radio resource management.

Evaluación del desempeño de un planificador de paquetes en el enlace de bajada de LTE empleando un algoritmo evolutivo


 El constante aumento de usuarios móviles y la demanda de aplicacionesde altos requerimientos de desempeño implican nuevos retos para el despliegue de los sistemas de comunicación inalámbricos, que pese a todas las limitaciones deben propender por la calidad de la experiencia de los abonados. La planificación de paquetes en el enlace de bajada juega un rol importante en los sistemas cuarta generación, ya que es la responsable de asignar en forma inteligente los recursos de radio a los usuarios, deacuerdo a un algoritmo establecido. En el estudio llevado a cabo se desarrolló un planificador de paquetes en el enlace de bajada de LTE basado en un algoritmo evolutivo; el desempeño obtenido es equiparable al de planificadores de paquetes convencionales
 

Comparative Analysis of Downlink Packet Scheduling Algorithms in 3GPP LTE Networks

Long Term Evolution (LTE) mobile network aims to support high speed network services even in highmobility scenarios. To achieve this goal, LTE adopts some advanced features in Radio Resource Management (RRM) procedures. Among them, LTE packet scheduling plays a fundamental role in maximising system performance. In this paper, a comparative analysis on the performances of Proportional Fair (PF), Exponential/Proportional Fair (EXP/PF), Exponential (EXP) Rule, MaximumLargest Weighted Delay First (M-LWDF), Logarithmic (LOG) Rule and Frame Level Scheduler (FLS) LTE downlink packet scheduling algorithms is reported. Performance is evaluated in single cell with interference environment while increasing user number and user speed. Results show that for multimedia flow, FLS scheme outperforms other five schemes in terms of packet delay, packet loss ratio, and average throughput, whereas for best-effort flow, EXP-PF scheme shows better average throughput performance on average as compared with other algorithms being considered herein.

On Uplink and Downlink Packet Scheduling in Full-Duplex Wireless Mesh Networks

We study the problem of deriving the shortest schedule required to forward both uplink and downlink packets in wireless mesh networks (WMNs) with full duplex capability. We derive the theoretical upper and lower bound of the schedule, and propose a novel centralized algorithm, called UDMAC, that greedily generates a schedule on a path-by-path basis and ensures nodes have sufficient antennas for transmissions, receptions, and interference cancellation. Our results show that UDMAC outperforms a state-of-the-art half-duplex scheduling algorithm by at least 60% in terms of schedule length.

A Comparison Study Between the Downlink Packet Scheduling Algorithms in LTE Networks

LTE networks are the latest generation of wireless networks based on IP architecture; it is standardized by the 3GPP in its Rel.8. LTE networks are implemented practically to access internet with very high data rates with using various multimedia services.This paper is based on five types of downlink packet scheduling algorithms in LTE networks,It examines the impact of throughput, the fairness and the spectral efficiency of each scheduling algorithms when the speed of UE (User Equipment) and the number of UEs are changed. A comparison between the scheduling algorithms has been done using Vienna LTE SYSTEM LEVEL Simulator.

Implementation of packet scheduling algorithms in LTE-Sim

In this research paper we have implemented downlink packet scheduling algorithms in LTE-Sim simulation for LTE cellular networks. The implementation includes adding two packet scheduling algorithms (Round Robin and MaxRate). The performance of these algorithms is tested for various types of real time service (video) and non real time service(data) for fixed and mobile users at various speeds 3, and 120Km/h in LTE-Sim simulator. The simulation was setup with varying number of users 120 in fixed boundedregions of 1 km radius.The goal of this project is to study the simulation of Radio Resource Management (RRM) in 4G networks using LTE-Sim. In particular, it focuses on the comprehensive performance testing of packet scheduling algorithms (such as Max Rate, Round Robin, PF, MLWDF, EXP). The paper shows the results of implementing of these algorithms and testing their performance.

Delay-Based Weighted Proportional Fair Algorithm for LTE Downlink Packet Scheduling

This paper proposes an algorithm of delay-based weighted proportional fair (DBWPF) for downlink packet scheduling in the long term evolution cellular networks. Besides the tradeoff between throughput and throughput fairness, which is the target of the traditional PF scheduling, DBWPF also considers the weighted average delay of each user, where the user with larger delay is more likely to obtain resources. With this treatment, the DBWPF scheduling is conducive to achieve delay fairness and implementation rate fairness between different users, which is significant in the case that users in a cell have different traffic volumes. Simulation results indicate that the proposed method has an approximate throughput and throughput fairness compared with the PF scheduling. Moreover, in the aspects of delay fairness and implementation rate fairness, DBWPF is competitively superior to the traditional algorithms.