Priority Packets Research Articles

QoS-Aware and Load-Balance Routing for IEEE 802.11s Based Neighborhood Area Network in Smart Grid

Monitoring and transforming smart grid (SG) assets in a timely manner is highly desired for emerging smart grid applications. This critically requires the design of a neighborhood area network (NAN) which is capable of providing high-efficiency and reliable two-way last mile communication from meters to other SG domains. For this demand, IEEE 802.11s based wireless mesh network (WMN) is anticipated to be utilized in a NAN as it can provide high scalability, high-speed and cost-effective wireless transmission. In this paper, we propose a NAN QoS-aware and load-balance routing scheme (NQA-LB) based on the default hybrid wireless mesh protocol (HWMP) of IEEE 802.11s, which aims to address multiple QoS requirements from different NAN applications, and guarantee the highly reliability transfer of NAN traffic data towards gateway. With the NQA-LB, various QoS requirements can be satisfied through sufficient differentiated services as well as network congestion is mitigated by achieving load balance between multiple transmission paths. In order to improve the reliability of NQA-LB, we present an EDCA based adaptive priority adjustment scheme, called AP-EDCA, which dynamically adjusts packet's priority to increase the throughput under low load condition and to mitigate the collision under heavy load condition to improve the reliability of applications with high QoS requirements. Extensive simulation experiments demonstrate the superiority of the proposed scheme in terms of packet delivery ratio, end-to-end delay and throughput while satisfies various QoS requirements much better at the same time.

Network coding-based approach for efficient video streaming over MANET

Video streaming over mobile ad-hoc networks is becoming a highly important application for reliably delivering the content between the user and the content storage node. The key challenge is, hence, to address the impact of the user mobility on the quality of the delivered video. Accordingly, the pioneering concept of network coding (NC) emerges as a promising approach for improving the video transmission quality mainly in multicast mobile environment. This work focuses on improving the Quality of Service of video streaming over mobile ad-hoc networks using random NC. We consider video coded by the widely-used H264/SVC codec that generates packets with different priorities and provides traffic differentiation using the IEEE 802.11e MAC. Intuitively, focusing on lowering the error transmission of high priority packets leads to enhance the video streaming quality. Accordingly, this work develops and proposes a new scalable transmission scheme that decreases the loss of high priority packets. Our approach, named Extended Multicast Scalable Video Transmission using Classification-Scheduling Algorithms and Network Coding over MANET (and denoted EMSCNC), adopts a cross layer design between the H.264/SVC codec, the network and MAC layers. Moreover, we develop an analytical framework allowing the performance evaluation in terms of throughput, delay, and packet delivery ratio. Simulation results validate our analytical model and confirm the substantial performance improvement brought by our approach.

Fuzzy and Parallel Enhanced Congestion Detection and Avoidance for Multiple Class of Traffic in Wireless Network

Background/Objectives: Congestion in wireless network causes loss of packets, longer delay and throughput degradation. So it is always a major concern to network. Many sources send data of different priorities in different applications like Multimedia. So weighted fairness for these applications is also required. Methods: To address these issues we propose a protocol named FPECODA for Mobile Ad hoc Network. Findings: It uses the GPU for parallel version of algorithm for finding the Dynamic Priority of packets, sorting algorithm etc. It also applies the fuzzy logic for rate control of node. Subsequently handling the congestion will become more effective by: a) Bottleneck node based source data sending rate control. b) Flexible Queue Scheduler for packets transfer. Improvements: Experimental results demonstrate that processing of packets becomes significantly faster than CPU only based algorithm. Also it will be very efficient in terms of throughput, end to end delay and fairness in network.

Opportunity cooperative embedded platform and control mechanism based on selectivity of time and frequency domain

The opportunistic cooperative platform and adaptive cooperative control scheme were proposed based on the redundancy degree and priority of cooperative data packet, as well as selective characteristics of time domain and frequency domain. First, opportunistic cooperative platform was defined according to the cooperative data stream scale, mapping algorithm, and priority and redundancy of cooperative data packets. Second, under the single or multiple relay network environment and mobility of sensors, the selective characteristics of time and frequency domain were studied. The active domain and negative domain were proposed for adjusting and improving the opportunistic cooperative platform. Third, the opportunistic cooperative control mechanism based on selectivity of time domain and frequency domain (OCC-TFD) was proposed for improving the performance of wireless sensor networks. Finally, the mathematical results demonstrated that the proposed platform and scheme can provide reliable, robust, and efficient data communication services of wireless sensor networks.

Dynamic Multi Threshold Priority Packet Scheduling Algorithms

Packet scheduling algorithms are developed in order to use shared transmission resources efficiently. Various application packets such as real and non-real time packets might have different QoS requirements and traditional scheduling algorithms might be insufficient to respond to the applications needs. In this paper, two packet scheduling algorithms are proposed to overcome this problem: Dynamic multi threshold priority packet scheduling (DMTPS) and dynamic multi threshold priority with urgency packet scheduling (DMTPUS). The proposed algorithms aim to provide a better QoS level with a decrease in delay time and loss ratio for the low priority packets while still maintaining acceptable fairness towards high priority packets. To evaluate the performance of DMTPS and DMTPUS algorithms, they are compared with the commonly used scheduling algorithms such as first come first served (FCFS) and fixed priority. Simulation results illustrate that the dynamic multi threshold priority packet scheduling algorithms can provide a better QoS for low priority packets without decreasing the QoS levels of high priority packets.

Big data in mobile social networks: a QoE-oriented framework

Due to the rapid development of mobile social networks, mobile big data play an important role in providing mobile social users with various mobile services. However, as mobile big data have inherent properties, current MSNs face a challenge to provide mobile social user with a satisfactory quality of experience. Therefore, in this article, we propose a novel framework to deliver mobile big data over content- centric mobile social networks. At first, the characteristics and challenges of mobile big data are studied. Then the content-centric network architecture to deliver mobile big data in MSNs is presented, where each datum consists of interest packets and data packets, respectively. Next, how to select the agent node to forward interest packets and the relay node to transmit data packets are given by defining priorities of interest packets and data packets. Finally, simulation results show the performance of our framework with varied parameters.

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.

Performance Analysis of Wavelength Division Multiplexing Asynchronous Internet Router Employing Space Priority Mechanism under Self-Similar Traffic Input—Multi-Server Queueing System with Markovian Input and Erlang-k Services

In this paper, we analyze the queueing behaviour of wavelength division multiplexing (WDM) Internet router employing partial buffer sharing (PBS) mechanism with self-similar traffic input. In view of WDM technology in networking, each output port of the router is modelled as multi-server queueing system. To guarantee the quality of service (QoS) in Broadband integrated services digital network (B-ISDN), PBS mechanism is a promising one. As Markov modulated Poisson process (MMPP) emulates self-similar Internet traffic, we can use MMPP as input process of queueing system to investigate queueing behaviour of the router. In general, as network traffic is asynchronous (unslotted) and of variable packet lengths, service times (packet lengths) are assumed to follow Erlang-k distribution. Since, the said distribution is relatively general compared to deterministic and exponential. Hence, specific output port of the router is modelled as MMPP/Ek/s/C queueing system. The long-term performance measures namely high priority and low priority packet loss probabilities and the short-term performance measures namely mean lengths of critical and non-critical periods against the system parameters and traffic parameters are computed by means of matrix-geometric methods and approximate Markovian model. This kind of analysis is useful in dimensioning the router under self-similar traffic input employing PBS mechanism to provide differentiated services (DiffServ) and QoS guarantee.

Optimization of Access Threshold for Cognitive Radio Networks with Prioritized Secondary Users

We propose an access control scheme in cognitive radio networks with prioritized Secondary Users (SUs). Considering the different types of data in the networks, the SU packets in the system are divided into SU1 packets with higher priority and SU2 packets with lower priority. In order to control the access of the SU2 packets (including the new arrival SU2 packets and the interrupted SU2 packets), a dynamic access threshold is set. By building a discrete-time queueing model and constructing a three-dimensional Markov chain with the number of the three types of packets in the system, we derive some performance measures of the two types of the SU packets. Then, with numerical results, we show the change trends for the different performance measures. At last, considering the tradeoff between the throughput and the average delay of the SU2 packets, we build a net benefit function to make optimization for the access threshold.

PT-BAR: Prioritized Thermo-Buffer Based Adaptive Routing Protocol for Network-on-chip

The Network-on-Chip (NoC) is an important technology that replaced the traditional bus-based architecture for the future of System-on-Chip (SoC). The NoC system provides better scalability, performance, reliability, etc. to the SoC networks by implementing the principles of interconnection networks and packet switching. One of the major problems in NoC is the increase in temperature of the nodes that leads to unbalanced thermal management within the network. This further leads to performance degradation due to damaged nodes. A novel thermal management scheme is proposed in this paper, which makes use of the thermal state and buffer state of the nodes for routing the packets. The proposed Prioritized Thermo-Buffer based Adaptive Routing (PT-BAR) protocol maintains a thermal region based on the thermal balance of the nodes within the region. Only high priority packets are transferred through the thermal region to preserve thermal balance throughout the network. During packet transfers the thermo-buffer model considers the energy consumption and thermal conductivity of nodes to calculate temperature and the current buffer state of the node. This factor is used to choose a path that will provide better performance in end-to-end delay and throughput while preserving the thermal balance of the network. Proposed PT-BAR reduces the temperature by 1.5° C than the existing protocol by making use of the efficient thermal model and buffer models for the efficient routing strategy.

On Demand Priority Packet Forwarding for TCP Performance Enhancement in Cognitive Mobile IP Networks

Spectrum mobility packet drops due to dynamic channel handover in optimized cognitive mobile IP leads to end-to-end connection disruption and severe performance degradation in transmission control protocol (TCP). In traditional mobile IP, buffered packet drops in between base station and the mobile node are only due to node mobility and network congestion. To date, number of packet buffering and forwarding mechanisms were proposed to reduce the node mobility and buffer overflow packet drops. But, dynamic spectrum access in cognitive mobile IP introduces spectrum mobility packet drops apart from node mobility and network congestion. Hence, it is significant to enhance the existing mobile IP to support the spectrum handover framework and reduce spectrum mobility packet drops during primary user (PU) active in the current cognitive radio channel. In this work, on-demand priority packet forwarding with spectrum handover support is proposed to reduce the packet drops due to spectrum mobility, node mobility and network congestion. In addition, adaptive power control algorithm is proposed to reduce the collisions due to hidden PU receivers at edge PU coverage area. Experimental results disclose that the performance of TCP with proposed on-demand priority packet forwarding outperforms the existing packet buffering mechanisms.

Routing Imperative Data Packets in Wireless Sensor Networks using Congestion Free Path

The congestion problem in Wireless Sensor Networks (WSNS) is quite different from that in traditional networks. Most current congestion control algorithms try to alleviate the congestion by reducing the rate at which the source nodes inject packets into the network. Congestion occurs when too many source nodes are sending data for network to handle. It causes missing of data packets, increases energy efficiency and transmission delay. Transferring crucial data in critical situation is a challenging problem in WSNS. In sensor network two types of paths are constructed for data transmission, they are single path and multi path. Single path data transmission leads to more congestion as all data are send through a single path. Multi path data transmission reduces congestion by sending data based on the urgency. The proposed work dynamically schedules different type of data flow. To assign priority for each data packets it avoids the starvation problem by finding buffer occupancy of each intermediate node by finding the shortest path. Imperative data packets routed using congestion free path with minimum delay in WSNS increase the network throughput and efficiency.

Loss Visibility Optimized Real-Time Video Transmission Over MIMO Systems

The structured nature of video data motivates introducing video-aware decisions that make use of this structure for improved video transmission over wireless networks . In this paper, we introduce an architecture for real-time video transmission over multiple-input multiple-output (MIMO) wireless communication systems using loss visibility side information . We quantify the perceptual importance of a packet through the packet loss visibility and use the loss visibility distribution to provide a notion of relative packet importance . To jointly achieve high video quality and low latency, we define the optimization objective function as the throughput weighted by the loss visibility of each packet, a proxy for the total perceptual value of successful packets per unit of time. We solve the problem of mapping video packets to MIMO subchannels and adapting per-stream rates to maximize the proposed objective . We show that the solution enables jointly reaping gains in terms of improved video quality and lower latency. Optimized packet-stream mapping enables transmission of more relevant packets over more reliable streams while unequal modulation opportunistically increases the transmission rate on the stronger streams to enable low latency delivery of high priority packets. Tested on H.264-encoded video sequences, for a $4 \times 4$ MIMO system with three spatial streams, the proposed architecture achieves 8 dB power reduction for the same video quality and supports $2.4\times $ higher throughput due to unequal modulation. Furthermore, the gains are achieved at the expense of few bits of cross-layer overhead rather than a complex cross-layer design.

Adaptive Q-aware Scheduling Algorithm for Multi-Service Flows in 802.16j Networks

The IEEE 802.16j standard defines Mobile Multi-hop Relay Wireless Cellular Networks. Introduction of Relays in WiMAX networks pose new challenges along with the advantages of High Throughput and Improved Coverage Area. Thus Scheduling plays a crucial role in Mobile Multihop Relay(MMR) Wireless Networks. The Queue aware scheduling algorithm [1] maximizes the throughput by considering Queues at Base Station(BS) and Relay Station(RS) as well along with Concurrent Transmission Technique. In Queue aware scheduling, as all the arrived packets are queued up in FCFS manner, the high priority packets are obviously delayed. In this paper, QOS guarantee is incorporated by considering multiple Queues for different service flows at Base Station for Queue aware scheduling algorithm. Real Time Adaptive Scheme (RTAS) [2] is modified to improve throughput and used for picking the packets from service class sub queues(SCSQ) to include them in BS input queue. The results show that high priority packets are given proper importance while considering low priority packets as well. Throughput is also increased because of Modified RTAS and Concurrent Transmission Technique of Queue aware scheduling. General Terms WiMAX, Scheduling, Algorithm, Throughput, Queue, Packet

English

English

Agent based Monitoring and Scheduling Technique Framework for Backup Configurations

In Multi Route Configurations (MRC) protocol when failure is detected, it forwards the packets over preconfigured alternative next-hops and immediately recovers from single or multiple failures. Multipath routing provides multipath communication and improves network transmission reliability. However, when there is a huge amount of traffic in the network existing MRC follows default scheduling which results in large transmission delay for high priority packet. Hence it is a challenging problem, and highly influences the performance of MRC. In this paper, we propose an Agent based Monitoring and Scheduling Technique (AMST) algorithm which provides a generic framework for packet scheduling. The main idea of AMST algorithm is to schedule the packets based on its priority and by selecting the transmission path with lowest transmission delay.

Efficient priority packet recovery based on network coding in DVB-IPDC system

In DVB-IPDC system, due to the constraints of handheld devices and the broadcast nature of wireless network, packet loss is inevitable. ECDR-NC proposed is a retransmission encoding packet selection algorithm based on the dynamic information updating, which can find the current most effective complete decoding packet. ECDR-NC can not only avoid the redundant encoding packets due to the overlapping among encoding packets, but also reduce the computational complexity compared with the traditional encoding schemes. Furthermore, the retransmission upper bound of ECDR-NC is fully controlled. In time-sensitive applications, to maximize the aggregate number of recovery packets while minimizing the total number of discarded packets due to the time limit according to the priority preference, the adaptive priority scheme EPNC is formulized, and the weighted relation graph is constructed to find the maximum-weighted encoding packets sequence according to the decoding gains. In the same network environment, the performances comparisons between PNC and EPNC show that EPNC is more efficient and more rational, and the average discarded packets ratios of EPNC can be reduced about 18%∼27%. The main contributions of this paper are an effective retransmission encoding packet selection algorithm ECDR-NC proposed, and a new adaptive priority recovery scheme EPNC introduced into DVB-IPDC system.

A comparison of Mamdani and Sugeno fuzzy based packet scheduler for MANET with a realistic wireless propagation model

The mobile nature of the nodes in a wireless mobile ad-hoc network (MANET) and the error prone link connectivity between nodes pose many challenges. These include frequent route changes, high packet loss, etc. Such problems increase the end-to-end delay and decrease the throughput. This paper proposes two adaptive priority packet scheduling algorithms for MANET based on Mamdani and Sugeno fuzzy inference system. The fuzzy systems consist of three input variables: data rate, signal-to-noise ratio (SNR) and queue size. The fuzzy decision system has been optimised to improve its efficiency. Both fuzzy systems were verified using the Matlab fuzzy toolbox and the performance of both algorithms were evaluated using the riverbed modeler (formally known as OPNET modeler). The results were compared to an existing fuzzy scheduler under various network loads, for constant-bit-rate (CBR) and variable-bit-rate (VBR) traffic. The measuring metrics which form the basis for performance evaluation are end-to-end delay, throughput and packet delivery ratio. The proposed Mamdani and Sugeno scheduler perform better than the existing scheduler for CBR traffic. The end-to-end delay for Mamdani and Sugeno scheduler was reduced by an average of 52% and 54%, respectively. The performance of the throughput and packet delivery ratio for CBR traffic are very similar to the existing scheduler because of the characteristic of the traffic. The network was also at full capacity. The proposed schedulers also showed a better performance for VBR traffic. The end-to-end delay was reduced by an average of 38% and 52%, respectively. Both the throughput and packet delivery ratio (PDR) increased by an average of 53% and 47%, respectively. The Mamdani scheduler is more computationally complex than the Sugeno scheduler, even though they both showed similar network performance. Thus, the Sugeno scheduler is more suitable for real-time applications.

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.

The Effects of Different Congestion Management Algorithms over Voip Performance

This paper presents one of the features of DS (Differentiated Services) architecture, namely the queuing or congestion management. Packets can be placed into separate buffer queues, on the basis of the DS value. Several forwarding policies can be used to favor high priority packets in different ways. The major reason for queuing is that the router must hold the packet in its memory while the outgoing interface is busy with sending another packet. The main goal is to compare the performance of the following queuing mechanisms using a laboratory environment: FIFO (First-In First-Out), CQ (Custom Queuing), PQ (Priority Queuing), WFQ (Weighted Fair Queuing), CBWFQ (Class Based Weighted Fair Queuing) and LLQ (Low Latency Queuing). The research is empirical and qualitative, the results are useful both in infocommunication and in education.