Effort Traffic Research Articles

A BP Network Control Approach for QoS-Aware MAC in Cloud Robotics

The basic idea of Cloud Robotics is dynamically uploading the compute-intensive applications to the cloud, which greatly enhances the intelligence of robots for the high processing and parallel ability of cloud. However, for the nature of uncertainty of mobility, different kinds of applications on robot may have different Quality of service (QoS). The paper proposes a BP network for QoS-aware MAC(BPFD-MAC) in Cloud Robotics form a view control theory, which can support both absolute and relative QoS guarantees while the energy saving. The hard and soft QoS constraints are de-coupled by normalized into a two-level cascade feedback loop. The former is Active Time Loop (AT-Loop) to enforce the absolute QoS guarantee for real-time application and the later is Contention Window Loop (CW-Loop) to enforce the relative QoS guarantee for Best Effort traffics. Finally, the Back-propagating (BP) neuron network based PID is used for self-tuning parameters and controller design. The hardware experiments demonstrate the feasibility of BPFD-MAC. Comparing with FD-MAC, BPFD-MAC has new feature of absolute QoS support and further developed two advantages:In the condition of heavy loads, BPFD have about 18% great throughput and 14% great power efficient; and in light load, BPFD have lower total energy consumption.

Introduction of a Novel Hybrid Weighted Exponential Logarithm-Maximum Throughput (HWEL-MT) Scheduler for QoS Improvement of LTE/4G Cellular Networks

The real-time broadcast of multimedia contents such as VoIP and video traffics in recent cellular networks is increasingly becoming common. In this regard, LTE networks with the objective of providing high speed data along with QoS assurance have been introduced. To perform this, schedulers in order to allocate of the resources to the traffics are used as channel-aware/QoS-aware. The most important and effective schedulers are EXP RULE and E2M RULE for this type of networks but still requires improving of QoS parameters to reach an optimal level of performance. In this paper aims to improve the packet loss rate (PLR), latency and throughput parameters especially and improve the other QoS parameters generally in the downlink LTE networks, a new scheduler called Hybrid Weighted Exponential Logarithm-Maximum Throughput (HWEL-MT) RULE method has been proposed. By performing simulations and comparisons between output results of EXP-Rule, E2M RULE and HWEL-MT RULE schedulers for VoIP, video and best effort traffics, we have totally concluded that the proposed HWEL-MT scheduler is able to improve PLR, delay, throughput, fairness and spectral efficiency more than two other examined methods. The results have been presented and compared by implementing a LTE network included 5---70 mobile users in open source LTE-Sim software.

Bandwidth Partitioning and SINR Threshold Analysis of Fractional Frequency Reuse in OFDMA Cellular Networks for Real Time and Best Effort Traffic

To achieve high capacity in cellular networks, frequency reuse factor of unity is used. However, it suffers from heavy co-channel interference at cell edge regions. This leads to poor Signal to Interference plus Noise Ratio (SINR) and hence poor performance. fractional frequency reuse (FFR) is one of the methods being considered to improve cell edge performance. In this work we present the impact of SINR threshold and bandwidth partitioning on the successful deployment of FFR scheme. We have considered both real time (RT) and best effort (BE) traffic. In FFR, the total frequency resource is divided logically into cell center and cell edge user bands. However, while frequency resource is partitioned into two segments, the amount of bandwidth required by cell center and cell edge users is quite different and influences the system performance. We developed the semi analytical approach to evaluate the average bandwidth required by cell center and edge band users. From the analysis and simulation results it is seen that while grade of service (GoS) fair based method of choosing bandwidth partitioning ratio is best for RT traffic, while the only feasible method for BE traffic is dividing the bandwidth based on probability of a user to be in a given band which we termed as `Probability' method.

Cross Layer Adaptation for QoS in WSN

In this paper, we propose QoS aware MAC protocol for Wire- less Sensor Networks and its cross layer extension to network layer for providing QoS in delay sensitive WSN scenarios. In WSNs, there can be two types of traffic one is event driven traffic which requires immedi- ate attention and another is periodic reporting. Event driven traffic is classified as Class I(delay sensitive) traffic and periodic reporting is clas- sified as Class II(Best Effort) Traffic. MAC layer adaptation can take place in terms of (i) Dynamic contention window adjustment per class, (ii) Reducing the delay suffered by difference in Sleep schedules(DSS) of communicating nodes by dynamically adjusting Duty Cycle based on Utilization and DSS delay of class I traffic, (iii) Different DIFS (DCF Inter Frame Spacing) per class, (iv) Adjusting all the three schemes pro- pose d above simultaneously. Cross layer extension is also proposed, in which MAC layer uses ne twork layer's next hop information for better adaptation of duty cycle based on DSS delay. Routing protocols can uti- lize MAC layer parameter DSS delay to select the routes which offer least DSS delay latency, there by minimizing the overall end-to-end delay.

Topology-aware wavelength partitioning for DWDM OBS networks: A novel approach for absolute QoS provisioning

Optical Burst Switching (OBS) is a promising switching technology for the next generation all-optical networks. An OBS network without wavelength converters and fiber delay lines can be implemented simply and cost-effectively using the existing technology. However, this kind of networks suffers from a relatively high burst loss probability at the OBS core nodes. To overcome this issue and consolidate OBS networks with QoS provisioning capabilities, we propose a wavelength partitioning approach, called Optimization-based Topology-aware Wavelength Partitioning approach (OTWP). OTWP formulates the wavelength partitioning problem, based on the topology of the network, as an Integer Linear Programming (ILP) model and uses a tabu search algorithm (TS) to resolve large instances efficiently. We use OTWP to develop an absolute QoS differentiation scheme, called Absolute Fair Quality of service Differentiation scheme (AFQD). AFQD is the first absolute QoS provisioning scheme that guarantees loss-free transmission for high priority traffic, inside the OBS network, regardless of its topology. Also, we use OTWP to develop a wavelength assignment scheme, called Best Effort Traffic Wavelength Assignment scheme (BETWA). BETWA aims to reduce loss probability for best effort traffic. To make AFQD adaptive to non-uniform traffic, we develop a wavelength borrowing protocol, called Wavelength Borrowing Protocol (WBP). Numerical results show the effectiveness of the proposed tabu search algorithm to resolve large instances of the partitioning problem. Also, simulation results, using ns-2, show that: (a) AFQD provides an excellent quality of service differentiation; (b) BETWA substantially decreases the loss probability of best effort traffic to a remarkably low level for the OBS network under study; and (c) WBP makes AFQD adaptive to non-uniform traffic by reducing efficiently blocking probability for high priority traffic.

A Performance Summary of the Evolved 3G (E-UTRA) for Voice Over Internet and Best Effort Traffic

Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA) is a new technology that targets the long-term evolution (LTE) of third generation. The E-UTRA technology has recently been standardized by the Third-Generation Partnership Project (3GPP) as a set of (series_36) specifications. The standardization process is almost complete; this paper does not focus on comparing specific proposed schemes but instead aims to outline the system performance more in general. E-UTRA operates in the packet-switched domain; hence, all traffic is handled by the packet protocols. The analysis is shown for Voice over Internet Protocol (VoIP) and Best Effort (BE) data, as these are common examples of real-time and non-real-time traffic, respectively. The performance is given in the VoIP study as the number of satisfied voice users per cell and in the BE study as the cumulative probability distribution of user (or cell) throughput, which was scaled to the spectral efficiency values, given both at the mean and at the cell edge. The VoIP capacity extends beyond 350 users in downlink and 230 users in uplink, which is a considerable increase compared with the high-speed packet-access (HSPA) reference. The BE spectral efficiency meets the 3GPP targets and yields impressive gains of order 2.5-3 times the well-performing HSPA reference. This clearly exceeds the mean of 1.5 b/s/Hz/cell in downlink and 0.8 b/s/Hz/cell in uplink for a baseline antenna configuration with penetration loss of 20 dB. In some scenarios, these mean gains exceed four times the reference.

Enhancing Both Network and User Performance for Networks Supporting Best Effort Traffic

With a view on improving user-perceived performance on networks supporting best effort flows, e.g., multimedia/data file transfers, we propose a family of bandwidth allocation criteria that depends on the residual work of on-going transfers. Analysis and simulations show that allocating bandwidth in this fashion can significantly improve the user-perceived delay, bit transmission delay, and throughput over traditional approaches, e.g., by 58% on an 80% loaded linear network. A simple implementation based on TCP Reno, exemplifies how one might approach practically realizing such gains. We discuss several other advantages of incorporating such differentiation at the transport level. In particular we make the case that favoring small transfers combined with user impatience or peak rate constraints, both of which are natural mechanisms for users to express the utility of completing transfers, offers a lightweight approach to achieving good overall network goodput and/or utility for best effort networks.

Router Scheduling Configuration Based on the Maximization of Benefit and Carried Best Effort Traffic

This paper shows a configuration scheme for networks with WFQ schedulers. It guarantees maximum revenue for the service provider in the worst case of network congestion. We focus on best effort traffic and select those flows that maximize the benefit while keeping the network utilization high. We show that optimum network configuration is feasible based only on knowledge of the topology. Its dependence on the pricing scheme can be reduced and even eliminated. We offer a formulation that reaches a tradeoff between network utilization, fairness, and user satisfaction.

Polling Best Effort Traffic in Bluetooth

Bluetooth [1] is a wireless access technology where polling is used to share bandwidth among the nodes. We have introduced a new poller named Predictive Fair Poller (PFP) in [2, 3]. In this paper w...