Packet Scheduling Scheme Research Articles

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.

Joint Video Packet Scheduling, Subchannel Assignment and Power Allocation for Cognitive Heterogeneous Networks

In this paper, a joint video scheduling, subchannel assignment, and power allocation problem in cognitive heterogeneous networks are modeled as a mixed integer non-linear programming (MINLP), which maximizes the minimum video transmission quality among different secondary mobile terminals (MTs) subject to the total available energy at each secondary, the total interference power at each primary base station, the total available capacity at each radio interface of each secondary MTs, and the video sequence encoding characteristic. In order to solve it, we decompose the original MINLP as joint subchannel and power allocation problem and video packet scheduling problem. Then, we model the joint subchannel and power allocation problem as a max–min fractional programming, and transform it as a convex optimization problem. Finally, we utilize dual decomposition method to design a joint subchannel and power allocation algorithm, and propose a video packet scheduling scheme based on auction theory to maximize the video quality for each secondary MT. Simulation results demonstrate that the proposed framework not only improves the video transmission quality significantly, but also guarantees the fairness among different secondary MTs.

A New Wireless Multicast Queuing Design Using Network Coding and Data-Flow Model

A queue stability analysis in a wireless multicast network with packet erasure channels is studied in this letter. In particular, a new queuing model consisting of several sub-queues is introduced, where each packet in a sub-queue is associated with an index set indicating its intended users. Our objective is to maximize the input rate under the queue stability constraints. We formulate it as a linear programming problem and propose a network coding-based packet scheduling scheme that finds the optimal solution. Finally, the simulation results corroborate our method.

Distributed Channel Allocation for Ad-hoc Multichannel Cognitive Radio Networks

Cognitive radio network was proposed to use the spectrum resource more efficiently. In a multichannel ad-hoc cognitive radio network, there is no central station and requires distributed channel scheduling. An important requirement of the cognitive radio network is to avoid interference to primary networks. In this paper, the authors propose the distributed packet scheduling scheme for ad-hoc multichannel cognitive radio networks. Each secondary user calculates independently its own priority with probabilistic manner and selects one of multi channels considering the primary user’s traffic pattern to minimize interference to the primary networks.

Implementation and evaluation of dynamically weighted low complexity fair queuing (DWLC-FQ) algorithm for packet scheduling in WiMAX networks

Services provided by internet need guaranteed network performance. Efficient packet queuing and scheduling schemes play key role in achieving this. Internet engineering task force (IETF) has proposed Differentiated Services (DiffServ) architecture for IP network which is based on classifying packets in to different service classes and scheduling them. Scheduling schemes of today's wireless broadband networks work on service differentiation. In this paper, we present a novel packet queue scheduling algorithm called dynamically weighted low complexity fair queuing (DWLC-FQ) which is an improvement over weighted fair queuing (WFQ) and worst-case fair weighted fair queuing+ (WF2Q+). The proposed algorithm incorporates dynamic weight adjustment mechanism to cope with dynamics of data traffic such as burst and overload. It also reduces complexity associated with virtual time update and hence makes it suitable for high speed networks. Simulation results of proposed packet scheduling scheme demonstrate improvement in delay and drop rate performance for constant bit rate and video applications with very little or negligible impact on fairness.

A Survey on Scheduling Schemes with Security in Wireless Sensor Networks

Wireless Sensor Network (WSN) is highly distributed network of small and light weight node. The node has the limited battery lifetime. Packet scheduling is important in WSN to maintain fairness based on priority of the data and to reduce the end to end delay. Existing packet scheduling algorithm used were First Come First Served (FCFS), Preemptive, Non-Preemptive.In this paper Dynamic Multilevel Priority (DMP) Packet Scheduling Scheme with the Bit Rate classification is proposed. The threshold value check mechanism is also proposed to prevent the deadlock situation. To provide security we will be implementing the RC6 security algorithm.

Dynamic Core Allocation and Packet Scheduling in Multicore Network Processors

With ever increasing network traffic rates, multicore architectures for network processors have successfully provided performance improvements through high parallelism. However, naively allocating the network traffic to multiple cores without considering diversified applications and flow locality results in issues such as packet reordering, load imbalance and inefficient cache usage. Consequently, these issues degrade the performance of latency sensitive network processors by dropping packets or delivering packets out of order. In this paper, we propose a packet scheduling scheme that considers the multiple dimensions of locality to improve the throughput of a network processor while minimizing out of order packets. Our scheduling policy tries to maintain packet order my maintaining the flow locality, minimizes the migration of flows from one core to another by identifying the aggressive flows, and partitions the cores among multiple services to gain instruction cache locality. Our light weight hardware implementation shows improvement of 60 percent in the number of packets dropped and 80 percent in the number of out-of-order packet deliveries over previously proposed techniques.

Energy-Efficient, QoS-Aware Packet Scheduling in High-Speed Networks

In current commercial routers, faster network processor units (NPUs) in line cards (LCs) can significantly improve network QoS performance. However, this improvement may come at a high cost of energy consumption. In this paper, we propose and investigate two classes of QoS-aware DVFS-based packet scheduling schemes. The first class uses queue length (QL) to control execution rates in line cards, whereas the second uses link utilization to achieve the same purpose. Excessive reduction in execution rate to save energy, however, may result in a sharp increase in network delay. To address this challenge, different frequency scaling strategies are proposed, and the performance of their associated schedulers is investigated. The simulation results show that both QL-aware and Load-aware DVFS have potential for significant energy saving in high-speed networks, with acceptable delay performance. Furthermore, a simulation study is carried out to compare the performance of the proposed schemes to similar schemes described in the literature for different network environments and traffic loads. The results show that the $\text{m}\bar{\text{Q}}\text{LA}$ scheme achieves the best results, with performance gains of up to 9.5% energy saving, while meeting the QoS performance of the supported applications.

Two-Step Scheduling Scheme to Support Fairness and QoS in DVB-S2 System

The use of an efficient packet scheduling scheme for a forward link in satellite communication networks is very important to support fairness for each return channel satellite terminal (RCST) and the service differentiations for user traffics. To support fairness and QoS for each RCST with service-level agreement (SLA), the Adaptive Coding and Modulation (ACM) system in a satellite hub has to process packets with considering modulation and coding (MODCOD) and packet types. Although a DVB-S2 system with ACM scheme has higher transmission efficiency, it cannot offer fairness or quality of service (QoS) to RCSTs. Because the data are transmitted with high MODCOD in regions with clear skies, while data are transmitted using low MODCOD in regions experiencing rain events. In this paper, we propose a two-step scheduling scheme offering fairness and QoS to RCSTs, while minimizing a decrease in throughput. The proposed scheme is carried out performance evaluations using a computer simulation. As results of this simulation, the proposed scheduler was shown to support bandwidth fairness to an individual RCST, and provide a level of QoS differentiation for user traffics.

Enhanced IHMAC with Dead Line Aware Packet Scheduling Scheme for Wireless Sensor Networks

Enhanced IHMAC with Dead Line Aware Packet Scheduling Scheme for Wireless Sensor Networks

Packet scheduling in MIMO satellite long term evolution networks

Summary This paper deals with the performance evaluation of different packet scheduling schemes for Long Term Evolution mobile satellite systems based on the adoption of a multi-user MIMO technique. The major breakthrough of MIMO technology in terrestrial networks has motivated the interest here for the adoption of MIMO in mobile satellite systems as well. In particular, a land mobile dual-polarized GEO satellite system has been considered in this work. The aim of this paper is to propose new cross-layer packet scheduling schemes that achieve a good trade-off among throughput, QoS and fairness and to conduct performance comparisons with other scheduling schemes in the literature. This is the reason why this paper also proposes a new performance index that can be used to evaluate the overall performance of each scheduler. The work shows that the new cross-layer scheduler, called channel-based queue sensitive scheduler, attains the best performance in terms of the new comprehensive performance index, thus representing an interesting solution for future mobile satellite systems. Copyright © 2015 John Wiley & Sons, Ltd.

Measuring the impact of adversarial errors on packet scheduling strategies

In this paper, we explore the problem of achieving efficient packet transmission over unreliable links with worst-case occurrence of errors. In such a setup, even an omniscient offline scheduling strategy cannot achieve stability of the packet queue, nor is it able to use up all the available bandwidth. Hence, an important first step is to identify an appropriate metric to measure the efficiency of scheduling strategies in such a setting. To this end, we propose an asymptotic throughput metric which corresponds to the long-term competitive ratio of the algorithm with respect to the optimal. We then explore the impact of the error detection mechanism and feedback delay on our measure. We compare instantaneous with deferred error feedback, which requires a faulty packet to be fully received in order to detect the error. We propose algorithms for worst-case adversarial and stochastic packet arrival models, and formally analyze their performance. The asymptotic throughput achieved by these algorithms is shown to be close to optimal by deriving lower bounds on the metric and almost matching upper bounds for any algorithm in the considered settings. Our collection of results demonstrate the potential of using instantaneous feedback to improve the performance of communication systems in adverse environments.

A performance analysis on packet scheduling schemes based on an exponential rule for real-time traffic in LTE

Abstract Long-Term Evolution (LTE) was implemented to fulfill and satisfy users’ needs as well as their demands for an improvised, fast and efficient Quality of service (QoS). A minimal aggregate of waiting time in return would give users a better Quality of experience (QoE). Real-time service packet scheduling is an important process in allocating resources to users. An efficient packet scheduling scheme will be able to cater fairly and efficiently to its users in the LTE network. Hence, studies are performed focusing on real-time traffic which includes video as well as Voice over Internet Protocol (VoIP) transmissions. In this work, the existing exponential rule (EXP rule) is utilized to benchmark our proposed packet scheduling techniques so that we are able to further evaluate the scheduling performance. In response to the increasing likelihood of losing packets in the EXP rule’s algorithm and maximizing the throughput rate, several schemes have been experimented with. The proposed schemes include 1) simplified EXP rule (sEXP Rule), 2) modified EXP rule (mEXP Rule), 3) EXP rule with maximum throughput (MT) (EXP_MT Rule), and 4) enhanced EXP rule with MT (E2M). By adding MT as a weight to the EXP rule, the throughput is maximized, thus providing higher throughput rates for real-time and non-real-time traffic. The simulation results show that the sEXP rule has a better performance in throughput, packet loss rate (PLR), and spectral efficiency for video traffic. Aside from this, our proposed E2M rule performs better than the benchmark EXP rule and outperforms the other proposed schemes, as well. It is observed that the E2M rule has better QoS support for real-time transmission in terms of delay, packet loss, throughput and spectral efficiency, within the LTE network. Hence, our proposed E2M rule is an enhancement of the benchmark EXP rule, which is commonly used in LTE packet scheduling.

User popularity-based packet scheduling for congestion control in ad-hoc social networks

Traditional ad-hoc network packet scheduling schemes cannot fulfill the requirements of proximity-based ad-hoc social networks (ASNETs) and they do not behave properly in congested environments. To address this issue, we propose a user popularity-based packet scheduling scheme for congestion control in ASNETs called Pop-aware. The proposed algorithm exploits social popularity of sender nodes to prioritize all incoming flows. Pop-aware also provides fairness of service received by each flow. We evaluate the performance of Pop-aware through a series of simulations. In comparison with some existing scheduling algorithms, Pop-aware performs better in terms of control overhead, total overhead, average throughput, packet loss rate, packet delivery rate and average delay.

Quality of Service Provisioning for Real-Time Traffic in Cognitive Radio Networks

In this paper the problem of Quality of Service (QoS) provisioning for the Real-Time secondary traffic in Cognitive Radio Networks (CRNs) is investigated. Supporting the Real-Time (RT) traffic in CRNs is a complicated task which requires elaborate consideration in different aspects of the network. Here we consider a practical model for the network. Furthermore, a novel packet scheduling scheme is proposed which can efficiently provide the QoS requirements of the RT Secondary Users (SUs). The variations of the SNR of wireless frequency channels which result in variable transmission rates on the channels are also taken into account in the proposed scheme. The resulting QoS parameters of the RT SUs are calculated analytically. The obtained results are also verified by simulations. The results provide helpful insight for the support of RT traffic in CRNs.

Design and Analysis of EDF Scheduling Algorithm for a Chosen Network Traffic Problem: Implementation and Simulation Analysis

Abstract Workstations, CPU etc are in a period of transition, moving from a relatively slow network links and data oriented services to a high set fibre optic services and more diverse services. As such many of the hard and soft real time will not only demand high bandwidth but also a predictable and guarantee Quality of Service (QoS) along side, which is not offered in a best effort network (BE). The provision and terms of (QoS) to real-time applications is a key issue in promising broadband packet switched networks and network of other sorts. Applications such as voice and video typically require QoS guarantees in terms of end-to-end data transfer delays. Supporting the diverse and of course, heterogeneous delay requirements of applications with widely varying characteristics requires packet scheduling schemes more sophisticated than First-In-First-Out (FIFO) at each switch in the network(2) are one of most accepted examples of such scheduling schemes. This points to the convincing need for a QoS, which apportion a high network utilization to be realized. In this paper, we focus on the EDF scheduling scheme, since it is known to provide the optimal delay performance (2), in the deterministic environment, and can for this reason be expected to perform well in the real time setting as well. The large amount of bandwidth as promised by the future network also offer the integration of real time applications, hard or soft.

A Dynamic Packet Scheduling Scheme with Multilevel Priority for Wireless Sensor Network

Packet scheduling is one of the critical issues in wireless sensor networks. In WSNs most existing scheduling mechanisms use FCFS, non-preemptive or preemptive priority algorithms. However, most of these algorithms incur high processing overhead and high end-to-end transmission delay due to the FCFS concept and starvation of real time and nonreal time data packets in non-preemptive and preemptive priority scheduling algorithms. Also, these packet scheduling algorithms are predetermined and hence cannot change in application requirements of WSNs. Therefore, in this paper, we propose a dynamic multilevel priority (DMP) packet scheduling algorithm to overcome the short comes like starvation of real time data, end-to-end or data transmission delay, and to make the packet scheduling dynamic. It is well known that in DMP scheduling scheme, nodes are organized in hierarchical structure and each node (except those nodes which are located at last level of hierarchical structure) has three level of priority queues in which real time data packets go to highest priority queue and non-real time data packets go to other two queues based on certain threshold levels of their estimated processing time. The DMP scheme proposed in this work was implemented with network simulator (NS2) v.2.32. The results obtained (end-to-end delay, average waiting time, network lifetime, and energy consumption) indicate the proposed DMP scheme is superior to existing first come first serve (FCFS) packet scheduling scheme. General Terms Wireless Sensor Network, FCFS.

Efficient Scheduling of Packets in Wireless Sensor Networks Using Priority Based Scheduling Approach

The packet scheduling is essential and plays an important role to sense the element nodes with resource constraints in Wireless Networks. The packet scheduling scheme also scale the energy consumption and end-to-end information transmission delay in time period and non-real-time information packets during wireless transmission. The proposed Priority based Packet Scheduling (PPS) technique has a tendency to overcome the issues based on priority queues in a wireless network. The priority queue has three levels at each node, except those at the last virtual hierarchy level in the zone-based topology of wireless network. In the meantime packet square are measured and placed in the highest-priority queue and might pre-empt information packets in alternative queues. In the non-real-time period packet square are measured and placed into two alternative queues supported at a particular threshold of their calculable interval. The time period and non-real time information has two queues in a leaf node, since they did not receive information from alternative nodes which causes scale back end-to-end delay. The proposed PPS technique has affinity to evaluate performance through simulations for the time period and non-real-time information. Simulation results illustrate that the PPS Scheme outperforms typical schemes in terms of average information waiting time and end-to-end delay.

Probabilistic Prediction based Scheduling for Delay Sensitive Traffic in Internet of Things

This paper proposes a probabilistic prediction based approach for providing Quality of Service (QoS) to delay sensitive traffic for Internet of Things (IoT). A joint packet scheduling and dynamic bandwidth allocation scheme is proposed to provide service differentiation and preferential treatment to delay sensitive traffic. The scheduler focuses on reducing the waiting time of high priority delay sensitive services in the queue and simultaneously keeping the waiting time of other services within tolerable limits. The scheme uses the difference in probability of average queue length of high priority packets at previous cycle and current cycle to determine the probability of average weight required in the current cycle. This offers optimized bandwidth allocation to all the services by avoiding distribution of excess resources for high priority services and yet guaranteeing the services for it. The performance of the algorithm is investigated using MPEG-4 traffic traces under different system loading. The results show the improved performance with respect to waiting time for scheduling high priority packets and simultaneously keeping tolerable limits for waiting time and packet loss for other services.

A New Packet Scheduling Scheme in Satellite HSDPA Networks

ABSTRACTSatellite access networks serve as an extension of the terrestrial access networks counterparts to provide services to areas where terrestrial access is not technically or economically viable. This paper proposes a new packet scheduling scheme that is designed for satellite high speed downlink packet access (S-HSDPA) networks using a cross-layer approach. The proposed scheduler uses the channel state information (CSI), queuing factors and application type (QoS factors) in taking scheduling decisions. The performance of the proposed scheduler is favourably compared with other schedulers in literature. This paper also investigates the effect of the signal-to-noise ratio (SNR) margin that has been introduced to compensate for the propagation delay experienced in GEO satellites in order to ensure an appropriate CSI is used by packet scheduler in the Node B of the S-HSDPA network. The optimal SNR margin that will provide the best performance (capacity) is then computed.