scholarly journals Cross-layer performance control of wireless channels using active local profiles

2007 ◽  
Vol 3 (3) ◽  
pp. 148 ◽  
Author(s):  
D. Moltchanov
Keyword(s):  
Performance Optimization ◽  
Wireless Channels ◽  
Forward Error Correction ◽  
Wireless Channel ◽  
Distribution Functions ◽  
Wireless Access ◽  
Cross Layer ◽  
Performance Control ◽  
Adaptation Mechanisms ◽  
Wide Range

To optimize performance of applications running over wireless channels state-of-the-art wireless access technologies incorporate a number of channel adaptation mechanisms. While these mechanisms are expected to operate jointly providing the best possible performance for current wireless channel and traffic conditions, their joint effect is often difficult to predict. To control functionality of various channel adaptation mechanisms a new cross-layer performance optimization system is sought. This system should be responsible for exchange of control informationbetween different layers and further optimization of wireless channel performance. In this paper design of the cross-layer performance control system for wireless access technologies with dynamic adaptation of protocol parameters at different layers of the protocol stack is proposed. Functionalities of components of the system are isolated and described in detail. To determine the range of protocol parameters providing the best possible performance for a wide range of channel and arrival statistics the proposed system is analytically analyzed. Particularly, probability distribution functions of the number of lost frames and delay of a frame as functions of first- and second-order wireless channel and arrival statistics, automatic repeat request, forward error correction functionality, protocol data unit size at different layers are derived. Numerical examples illustrating performance of the whole system and its elements are provided. Obtainedresults demonstrate that the proposed system provide significant performance gains compared to static configuration of protocols.

scholarly journals Cross Layer Design based Hybrid Error Control for Packet Aggregation over WSN

2018 ◽  
Vol 7 (4.6) ◽  
pp. 382
Author(s):  
Lakshmi. S ◽  
Dr. Selvakumar raja.S
Keyword(s):  
Error Rate ◽  
Error Control ◽  
Forward Error Correction ◽  
Control Technique ◽  
Cross Layer ◽  
Cross Layer Design ◽  
Source Information ◽  
Packet Aggregation ◽  
Wide Range ◽  
Error Control Mechanism

In general sensor networks have a wide range of application and also play a major role in developing precision and timely information. Mostly it deals with real world applications and in many cases the data sensed by the nodes should deliver within the time constriction. Meeting the deadlines is mandate for the applications and the data should be processed as soon as possible and without major data losses. The objective of this scheme is to collect data with high accuracy and low latency. Collecting and processing the data by means of aggregation will greatly reduce the congestion data rate. Cross Layer Design based Hybrid Error Control (CLDHEC) mechanism is proposed for reducing error rate occurred in sensor network which includes formation of network, data aggregation and transmission. Error control technique named Adaptive Forward Error Correction is used to defend the video transmission by recovering source information losses. FEC mechanism along with packet range control greatly increases the FEC efficiency in wireless networks. The service quality for different kind of data can be improved by lessening error rate using adaptive error control mechanism with cross layered design during packet aggregation. 

A Cross-Layer Model for Video Multicast Based TCP-Adaptive FEC over Heterogeneous Networks

2010 ◽  
pp. 1879-1895
Author(s):  
Ghaida A. AL-Suhail ◽  
Liansheng Tan ◽  
Rodney A. Kennedy
Keyword(s):  
Forward Error Correction ◽  
Video Quality ◽  
Wireless Channel ◽  
Cross Layer ◽  
Radio Link ◽  
Layer Model ◽  
Data Link ◽  
Link Layer ◽  
Adaptive Fec ◽  
Forward Error

In this article, we present a simple cross-layer model that leads to the optimal throughput of multiple users for multicasting MPEG-4 video over a heterogeneous network. For heterogeneous wired-to-wireless network, at the last wireless hop there are bit errors associated with the link-layer packets that are arising in the wireless channel, in addition of overflow packet dropping over wired links. We employ a heuristic TCP function to optimize the cross-layer model of data link and physical (radio-link) layer. An adaptive Forward-Error-Correction (FEC) scheme is applied at the byte-level as well as at the packet-level. The corresponding optimal video quality can be evaluated at each client end. The results show that a server can significantly adapt to the bandwidth and FEC codes to maximize the video quality of service (QoS) in terms of temporal scaling when a maximum network throughput for each client is reached.

scholarly journals Improving Performance in Dense Wireless Spaces by Controlling Bulk Traffic

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Marat Zhanikeev
Keyword(s):  
Performance Optimization ◽  
Wireless Channels ◽  
Web Applications ◽  
Real Life ◽  
Access Point ◽  
Wireless Access ◽  
Wireless Devices ◽  
Simple Method ◽  
Traditional Design ◽  
Educational Applications

The growing number of wireless devices nowadays often results in congestion of wireless channels. In research, this topic is referred to as networking in dense wireless spaces. The literature on the topic shows that the biggest problem is the high number of concurrent sessions to a wireless access point. The obvious solution is to reduce the number of concurrent sessions. This paper proposes a simple method called Bulk-n-Pick which minimizes the number of prolonged concurrent sessions by separating bulk from sync traffic. Aiming at educational applications, under the proposed design, web applications would distribute the main bulk of content once at the beginning of a class and then rely on small messages for real time sync traffic during the class. For realistic performance analysis, this paper first performs real-life experiments with various counts of wireless devices, bulk sizes, and levels of sync intensity. Based on the experiments, this paper shows that the proposed Bulk-n-Pick method outperforms the traditional design even when only two concurrent bulk sessions are allowed. The experiment shows that up to 10 concurrent bulk sessions are feasible in practice. Based on these results, a method for online performance optimization is proposed and validated in a trace-based emulation.

scholarly journals A Study on the Usage of Cross-Layer Power Control and Forward Error Correction for Embedded Video Transmission over Wireless Links

2007 ◽  
Vol 2007 ◽  
pp. 1-14 ◽  
Author(s):  
Fabrizio Granelli ◽  
Cristina E. Costa ◽  
Aggelos K. Katsaggelos
Keyword(s):  
Power Control ◽  
Performance Optimization ◽  
Forward Error Correction ◽  
Rate Distortion ◽  
Analytical Framework ◽  
Theoretical Background ◽  
Cross Layer ◽  
Wireless Multimedia ◽  
Design Paradigm ◽  
Cross Layering

Cross-layering is a design paradigm for overcoming the limitations deriving from the ISO/OSI layering principle, thus improving the performance of communications in specific scenarios, such as wireless multimedia communications. However, most available solutions are based on empirical considerations, and do not provide a theoretical background supporting such approaches. The paper aims at providing an analytical framework for the study of single-hop video delivery over a wireless link, enabling cross-layer interactions for performance optimization using power control and FEC and providing a useful tool to determine the potential gain deriving from the employment of such design paradigm. The analysis is performed using rate-distortion information of an embedded video bitstream jointly with a Lagrangian power minimization approach. Simulation results underline that cross-layering can provide relevant improvement in specific environments and that the proposed approach is able to capitalize on the advantage deriving from its deployment.

scholarly journals Pathwise optimality of the exponential scheduling rule for wireless channels

2004 ◽  
Vol 36 (04) ◽  
pp. 1021-1045 ◽  
Author(s):  
Sanjay Shakkottai ◽  
R. Srikant ◽  
Alexander L. Stolyar
Keyword(s):  
Queue Length ◽  
Wireless Channels ◽  
Unique Feature ◽  
Heavy Traffic ◽  
Wireless Channel ◽  
Service Rate ◽  
Resource Pooling ◽  
Scheduling Policy ◽  
Multiple Data ◽  
Heavy Traffic Limit

We consider the problem of scheduling the transmissions of multiple data users (flows) sharing the same wireless channel (server). The unique feature of this problem is the fact that the capacity (service rate) of the channel varies randomly with time and asynchronously for different users. We study a scheduling policy called the exponential scheduling rule, which was introduced in an earlier paper. Given a system withNusers, and any set of positive numbers {an},n= 1, 2,…,N, we show that in a heavy-traffic limit, under a nonrestrictive ‘complete resource pooling’ condition, this algorithm has the property that, for each timet, it (asymptotically) minimizes maxnanq̃n(t), whereq̃n(t) is the queue length of usernin the heavy-traffic regime.

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