Packet Scheduling Research Articles

Packet priority assignment for wireless control systems of multiple physical systems

Wireless control systems (WCSs) have gained much attention lately, due to their easy deployment and flexibility compared to wired control systems. However, this comes at the cost of possibly increased network delay and packet losses, that can significantly impact the control system performance, and possibly its stability. Such problems become even more relevant if the network is shared among different control systems, and thus becomes a scarce resource, like in Industrial Internet of Things applications. In this paper, we aim at minimizing the performance degradation of the WCS with multiple physical systems sharing a network. We propose a dynamic packet scheduling solution to minimize the performance error of WCS, by dynamically determining the packet priorities of different control systems and characteristic of network paths. We consider two cases for network path selection: (1) network delay only by developing a worst-case end-to-end delay analysis; (2) network delay + reliability by proposing a new network quality model including both delay and packet losses, both of which are very important for the quality of output of the WCSs. Our solution is evaluated over two different use cases to show the generality of the approach: the WCS for a set of inverted pendula, and the WCS for small modular reactors in a nuclear power plant. The results show that the proposed approach allows for a more stable performance even in presence of highly nonlinear systems, sensitive to time-varying delays, as well as in presence of high network interference.

A-ECN Minimizing Queue Length for Datacenter Networks

Recently, Explicit Congestion Notification (ECN) has been leveraged by DCTCP and its successive protocols to reduce the latency in datacenters. However, we find that DCTCP may induce the queue underflow and high latency in multi-queue scenarios and even single-queue environments. Our analysis concludes that the problem is caused by improper ECN marking thresholds of DCTCP. In this paper, an Adaptive ECN (A-ECN) marking scheme is proposed to enhance the performance of the ECN marking scheme of DCTCP.A-ECN is designed to minimize queue length as well as keeping high link utilization. More importantly, A-ECN can adaptively adjust ECN marking thresholds in different scenarios to achieve good generality. Therefore, network operators can directly deploy A-ECN in various environments regardless of underlying bandwidth, packet schedulers and the number of concurrent flows. At last, the testbed evaluation results show that A-ECN can minimize queue length and maintain high throughput. The flow completion times (FCT) for short flows could be reduced by up to 40% compared to the ECN marking scheme of DCTCP.

A Design of Packet Scheduling Algorithm to Enhance QoS in High-Speed Downlink Packet Access (HSDPA) Core Network

Voice over Internet Protocol (VOIP) in an efficient manner is a basic requirement of modern era. The real time and non-real traffics demand customized communication provisioning to get guarantee of service. For this we proposed a user fulfillment design for facilitating packets switching in 3G cellular network to insure provisioning of QoS (quality of service) in DiffServ (Differentiated Services) Network. To enhance QoS for real time traffic by reducing delay, packet loss and jitter, we proposed Low latency queuing (LLQ) algorithm. In this paper, we focused on packet scheduling, Diffserv and QoS classes mapping into Universal Mobile telecommunication System (UMTS) classes and buffering. To associate different types of real time multimedia traffic, the QoS provisioning mechanism used different code points of Diffserv. The new idea in LLQ is to map the video and voice traffics against two separate queues and used priority queuing in Low latency queuing for voice traffic. The results got from reproductions shows that proposed calculation meets the QoS prerequisites.

Contract-Based Scheduling of URLLC Packets in Incumbent EMBB Traffic

Recently, the coexistence of ultra-reliable and low-latency communication (URLLC) and enhanced mobile broadband (eMBB) services on the same licensed spectrum has gained a lot of attention from both academia and industry. However, the coexistence of these services is not trivial due to the diverse multiple access protocols, contrasting frame distributions in the existing network, and the distinct quality of service requirements posed by these services. Therefore, such coexistence drives towards a challenging resource scheduling problem. To address this problem, in this paper, we first investigate the possibilities of scheduling URLLC packets in incumbent eMBB traffic. In this regard, we formulate an optimization problem for coexistence by dynamically adopting a superposition or puncturing scheme. In particular, the aim is to provide spectrum access to the URLLC users while reducing the intervention on incumbent eMBB users. Next, we apply the one-to-one matching game to find stable URLLC-eMBB pairs that can coexist on the same spectrum. Then, we apply the contract theory framework to design contracts for URLLC users to adopt the superposition scheme. Simulation results reveal that the proposed contract-based scheduling scheme achieves up to 63% of the eMBB rate for the “No URLLC” case compared to the “Puncturing” scheme.

A novel localised network coding-based overhearing strategy

Network coding is a very effective approach to improve network throughput and reduce end-to-end delay. However, the existing approaches cannot thoroughly solve the problem of how to deal with newly overheard packets when the buffer is full, meanwhile, coding node does not schedule the packets in coding queue according to the packets' information in overhearing buffer. As a result, these methodologies lack flexibility and require quite a few assumptions. To address these limitations, we propose a new network coding overhearing strategy which is based on data packet switching and scheduling (DPSS) algorithm. First, when overhearing buffer is full and the sink nodes have overheard new packets, sink nodes will drop the recently overheard packets but record their IDs; second, sink nodes report the packets' information to the coding node that schedules the packets in coding queue for ease of encoding. Finally, sink nodes delete the packets which have been used for decoding, and call for the ever dropped packets when decoding ratio reaches the threshold. Theoretical analysis and simulation demonstrate that, compared with traditional overhearing policies, our scheme gets higher coding ratio and less delay.

Viewport-Adaptive Scalable Multi-User Virtual Reality Mobile-Edge Streaming.

Virtual reality (VR) holds tremendous potential to advance our society, expected to make impact on quality of life, energy conservation, and the economy. To bring us closer to this vision, the present paper investigates a novel communications system that integrates for the first time scalable multi-layer 360° video tiling, viewport-adaptive rate-distortion optimal resource allocation, and VR-centric edge computing and caching, to enable next generation high-quality untethered VR streaming. Our system comprises a collection of 5G small cells that can pool their communication, computing, and storage resources to collectively deliver scalable 360° video content to mobile VR clients at much higher quality. The major contributions of the paper are the rigorous design of multi-layer 360° tiling and related models of statistical user navigation, analysis and optimization of edge-based multi-user VR streaming that integrates viewport adaptation and server cooperation, and base station 360° video packet scheduling. We also explore the possibility of network coded data operation and its implications for the analysis, optimization, and system performance we pursue in this setting. The advances introduced by our framework over the state-of-theart comprise considerable gains in delivered immersion fidelity, featuring much higher 360° viewport peak signal to noise ratio (PSNR) and VR video frame rates and spatial resolutions.

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

Design of a 640-Gbps Two-Stage Switch Fabric for Satellite On-Board Switches

Due to the limitation of hardware resources and high reliability requirements for satellite-borne switching equipments and the demand for the increasing network bandwidth, a new type of two-stage satellite on-board switch fabric is presented in this paper. The fully connected structure is composed of eight input modules and eight output modules. And each module has four shared-buffer memories, which guarantee the premise of high-throughput. Compared with the traditional three-stage CLOS switch fabric, central modules are not used in this design. And compared with the complicated inter-stage scheduling algorithm, this paper uses an improved WRR algorithm which supports multi-priority variable-length packets scheduling. This design reduces the consumption of hardware resources and meets the design requirements of satellite-borne switches. In addition, we used the Xilinx FPGA to implement this $32\times32$ two-stage switch fabric, and used ModelSim 10.6d to simulate and analyze the entire design. The simulation results show that the peak throughput of this structure can reach 640 Gbps when the system clock frequency is 200 MHz.

A Multipath Packet Scheduling Approach based on Buffer Acknowledgement for Congestion Control

Abstract Congestion is an important concern in both wired and wireless communication systems. Several technologies are in use for the data link, network, and transport layer to manage congestion. Conventional congestion control approaches are unreliable for transport layer protocols by means of congestion control mechanisms utilized for multimedia streaming. Packets that schedule flow control to employ multiple network interfaces to smoothly transmit streaming data play an important role in congestion control by overwhelming the intermediate node’s buffer and causing packet loss. In this paper, we propose a Multipath Packet Scheduling (MP-PS) approach to efficiently stream the data packets in multiple paths. It consists of a Multi-Path Packet Scheduler (MPS) to perform the path scheduling based on the path scheduling delay probability, and a Multipath Congestion Control (MCC) to regulate the congestion control through an explicit acknowledgment for the rate of transmission control based on packet delivery rate and buffer availability. It aims to reduce packet loss and improve the throughput utilizing the MP-PS approach. The proposed approach has been extensively simulated by means of a simulator and it showed improvised performance in provisions of throughput and buffer utilization when evaluated with the conventional approach.

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 ...

Scheduling Enhancements and Performance Evaluation of Downlink 5G Time-Sensitive Communications

Time-sensitive communications (TSC) in wireless networks is an emerging paradigm that gains research momentum as an enabler of the industrial Internet of Things. As compared to ultra-reliable low-latency communications (URLLC) in fifth-generation cellular networks, TSC has stricter requirements in terms of latency and reliability, and also demands absolute time-synchronization and on-time delivery of packets for deterministic and isochronous real-time applications. In this regard, a key question is how to schedule TSC traffic flows effectively. This paper presents a radio resource allocation strategy for deterministic downlink TSC flows leveraging traffic pattern knowledge. Taking physical layer control channel effects into account, a comparison of semi-persistent and dynamic packet scheduling methods is presented as well as necessary enhancements to link adaptation and interference coordination procedures. With the proposed methods, the network capacity in terms of number of supported TSC flows can be more than doubled compared to traditional dynamic scheduling methods as commonly assumed for URLLC applications.

Robust Modelling to Jointly Address Security Threats, Bandwidth Utilization, and Energy issues in IoT

The advent of Internet-of-Things (IoT) revolutionizes the mechanism of connectivity of massive chains of machine offering better improvement in data communication and analytical services. Review of existing approaches towards IoT performance improvement shows that there are still larger scope of enhancing the present solution. The proposed system introduces a mechanism where 3 different problems has been jointly addressed viz. security issues, channel capacity issues, energy depletion issues. The proposed model uses analytical research methodology where energy problem is offered common focus and linked with other two problem using stochastic method, probability logic, decision-making approach, packet scheduling, etc. The simulation outcome of the study shows that proposed system offers better energy efficiency, better resistivity against threats, and effective optimization of the bandwidth in contrast to existing related mechanism towards IoT ecosystem.

5MART: A 5G SMART Scheduling Framework for Optimizing QoS Through Reinforcement Learning

The massive growth in mobile data traffic and the heterogeneity and stringency of Quality of Service (QoS) requirements of various applications have put significant pressure on the underlying network infrastructure and represent an important challenge even for the very anticipated 5G networks. In this context, the solution is to employ smart Radio Resource Management (RRM) in general and innovative packet scheduling in particular in order to offer high flexibility and cope with both current and upcoming QoS challenges. Given the increasing demand for bandwidth-hungry applications, conventional scheduling strategies face significant problems in meeting the heterogeneous QoS requirements of various application classes under dynamic network conditions. This paper proposes 5MART , a 5G smart scheduling framework that manages the QoS provisioning for heterogeneous traffic. Reinforcement learning and neural networks are jointly used to find the most suitable scheduling decisions based on current networking conditions. Simulation results show that the proposed 5MART framework can achieve up to 50% improvement in terms of time fraction (in sub-frames) when the heterogeneous QoS constraints are met with respect to other state-of-the-art scheduling solutions.

A Delay Optimal Multiclass Packet Scheduler for General M2M Uplink

The uplink data arriving at the Machine-to-Machine (M2M) Application Server (AS) via M2M Aggregators (MAs) is fairly heterogeneous along several dimensions such as maximum permissible packet delay, arrival rate, and payload size, thus necessitating the design of Quality-of-Service (QoS) aware packet schedulers. In this paper, we classify the M2M uplink data into multiple QoS classes and use sigmoidal function to map the delay requirements of each class onto utility functions. We propose a delay-optimal multiclass packet scheduler at AS obtained by iteratively searching for the optimal fraction of time-sharing between all preemptive priority scheduling policies, such that it maximizes a proportionally fair system utility metric. The iterative optimization process leads to reduced complexity, thus facilitating its online implementation. We then extend this work to determine a jointly optimal packet scheduler at the MAs and AS. We significantly reduce its computational complexity by iteratively solving a distributed optimization problem, independently at MAs and AS. Using Monte Carlo simulations, we show that the proposed joint packet scheduler outperforms other state-of-the-art packet schedulers and results in (desirable) near-minimal delay-jitter for delay-sensitive traffic at the expense of (tolerable) higher delay-jitter for delay-tolerant traffic.

Transmission and Reception Alignment for User Equipment Energy Efficiency in LTE Networks

Energy efficiency has become an essential component in the design of communication protocols, especially for battery-enabled user equipment (UE) devices such as smartphones. In this letter, an energy-efficient UE packet scheduling scheme for LTE/LTE-Advanced cellular networks is proposed. It achieves energy savings by promoting the simultaneous occurrence of transmissions and receptions. Simulation results show that this approach improves the energy efficiency of the device by increasing the number of simultaneous transmissions and receptions; the network performance, however, suffers little impact.

Fast and Secure Packet Scheduling with Packet Level Redundancy Elimination in Dynamic Mobile Networks

Mobile networks are fast and flexible for effective communication, where it only needs a dynamic topology and unstructured network construction. Due to this flexible nature, the resource utilization and energy consumption is high when comparing to the other static networks. In this scenario, packet redundancy is major problem on mobile networks, which increases network traffic and energy. Currently redundancy elimination is performed using redundancy elimination (RE) solution, which affects the end-to-end privacy. To eliminate redundant packet transfers and provide fast and secure packet transfer in the dynamic mobile network, a new middle box framework is proposed in this paper. This framework is named as Sift Hub, which is a centre point to verify the packet redundancy and security violations. This includes four algorithms to perform packet redundancy elimination, packet scheduling and verification. The algorithms are One pass signature generation algorithm (OSGA) for packet security, Predictive encryption technique using enhanced hidden vector encryption algorithm for redundancy detection on encrypted traffic, Packet level data filtering algorithm (PLDF) for eliminating un-authenticated and redundant packets and RAPS-Redundancy aware packet scheduling algorithm for fast data scheduling over dynamic mobile networks. The Shift_Hub supports inter and intra packet level redundancy elimination and secure packet scheduling without affecting the end-to-end privacy. The Shift_Hub is implemented and the performance is evaluated on dynamic mobile network scenario created on NS2 simulator. The results shows, the proposed work gives better performance in finding and eliminating redundant packet in secure manner than the existing works.

5thgeneration Wireless Network using Distributed Power Control, Novel and round Robin Scheduling Algorithms

The demand for higher networking quality i.e., 5G technology and improved wireless connectivity is increasing rapidly in emerging Cyber-Physical Systems (CPS). In this paper, we looked at the question of reducing total power transmission with power control and resource allocation in 5 G networks where there is mutual interference between cells using the distributed resource allocation algorithm, Packet Scheduling and compared with Round Robin Scheduling algorithm. Power control was indeed an efficient way to enhance wireless system ability. It was assumed that energy levels can be allocated from a constant spectrum in prior job on energy control. But energy levels are allocated from a discrete set in practice. In this work, we consider minimizing the complete transmitted energy over specified discrete sets of available energy levels subject to maintaining an acceptable quality of signal for each mobile. Our algorithm has reduced computational complexity compared to the current optimization algorithm, where each resource is assigned to a maximum of one user over a period of time. Numerical results verify our proposed algorithm's efficiency and convergence.

Peer-to-Peer Energy Trading in DC Packetized Power Microgrids

As distributed energy resources (DERs) are widely deployed, DC packetized power microgrids have been considered as a promising solution to incorporate DERs effectively. In this paper, we consider a DC packetized power microgrid, where the energy is dispatched in the form of power packets with the assistance of a power router. However, the benefits of the microgrid can only be realized when energy subscribers (ESs) equipped with DERs actively participate in the energy market. Therefore, peer-to-peer (P2P) energy trading is necessary in the DC packetized power microgrid to encourage the usage of DERs. Different from P2P energy trading in AC microgrids, the dispatching capability of the router needs to be considered in DC microgrids, which will complicate the trading problem. To tackle this challenge, we formulate the P2P trading problem as an auction game, in which the demander ESs submit bids to compete for power packets, and a controller decides the energy allocation and power packet scheduling. Analysis of the proposed scheme is provided, and its effectiveness is validated through simulation.

Software-defined network assisted packet scheduling method for load balancing in mobile user concentrated cloud

Cloud Network provides a variety of applications and services to meet the requirements of increasing user demands. With its dedicated components, the cloud enables anywhere anytime access of resources to its associated users. A significant factor that holds the performance of the cloud is its congestion, due to unpredictable traffic and asynchronous user demands. Though load balancers serve the purpose of optimizing network traffic, congestion is unavoidable when the level of user demand increases. In this manuscript, a Resource-aware Packet-level Scheduling with Load Balancing (RPS-LB) algorithm is proposed to minimize congestion. In RPS, the incoming network traffic is disseminated through instantaneous neighbors by analyzing their Store and Forward (SF) factor. SF factor is pre-estimated through Estimated Transmission Count (ETX) metric. With this analysis, the reliability of the instantaneous neighbor for handling the current packet-level transmission is verified. This algorithm addresses the issues in user-level and flow-level to mitigate stagnancy and overflow of network traffic. Besides, the proposed load-balancing algorithm is defined as a linear optimization problem within definite constraints to prevent degradation proportional to user density. The performance of the proposed system is assessed by using the performance evaluation parameters such as Queue Utilization, Request Success Rate, Request Failure Rate, Response Time and Link Utilization. The simulation results show that the proposed system performs well than the existing systems.

Distributed Dynamic Packet Scheduling Framework for Handling Disturbances in Real-Time Wireless Networks

Real-time wireless networks (RTWNs) are fundamental to many Internet-of-Things (IoT) applications. RTWNs typically apply time-division multiple access (TDMA)-based media access control mechanisms and often demand deterministic end-to-end packet delivery to meet the given quality of service (QoS) requirements. Packet scheduling in an RTWN thus plays a critical role for achieving the desired performance but is a challenging problem especially when the RTWN is large and must deal with multiple disturbances (i.e., unexpected events causing abrupt workload changes associated with certain sensing tasks) occurring concurrently. This paper introduces a novel distributed dynamic packet scheduling framework, D $^2$2-PaS. D $^2$2-PaS is capable of processing disturbances and minimizes the number of dropped packets while ensuring that all critical events due to disturbances are handled by their deadlines. As a distributed approach, D $^2$2-PaS constructs schedules locally at individual nodes, which significantly reduces the amount of schedule-related information to be broadcast by the gateway. As a dynamic approach, D $^2$2-PaS applies a lightweight packet dropping algorithm to determine on-line at the gateway which packets can be dropped in response to disturbances and disseminate this information to the network. D $^2$2-PaS has been implemented on a multi-hop RTWN testbed to validate its applicability on hardware and a popular RTWN stack. Both testbed measurements and extensive simulation results demonstrate the effectiveness of D $^2$2-PaS.