Alfonso Ariza Quintana

GREENIE: a novel hybrid routing protocol for efficient video streaming over wireless mesh networks

In recent years, video streaming over wireless mesh networks (WMNs) has been of great interest among the users. In WMNs, although node mobility and scalability are the two most important well-known advantages by end-users, they can decrease the perceived video quality on receivers with increasing the probability of path failure, especially when the number of mobile mesh nodes and their mobility speeds increase. Therefore, the necessity of employing an efficient routing protocol to consider the effects of node mobility is inevitable. Moreover, the interference can be sharply increased, especially on the gateways, when there are many mobile mesh nodes in a WMN. Interference does not permit the system to support many STA and mobile mesh nodes. In order to cope with these challenges, this study introduces and evaluates a g ood hybrid r outing protocol for data dissemination which e fficiently and e ffectively routes packets in a wireless mesh n etwork and i ntelligently e mploys proactive and reactive routing protocols based on the node mobility (GREENIE) for efficient video streaming over WMNs and extensively compares it with other routing protocols including hybrid wireless mesh protocol, proactive, reactive, and spanning trees using OMNET++ simulator. GREENIE intelligently distinguishes mobile from static nodes and selects the most stable path between a source and a destination which leads to higher perceived video quality on receivers. The results show the impact of GREENIE on the perceived video quality so that it considerably outperforms other routing protocols in terms of the total number of successfully received packets, the end-to-end delay, and the imposed routing overhead on the system. One of the main advantages of GREENIE is that it performs routing in the medium access control layer without applying any change in the functions of the internet protocol layer.

MATIN: a random network coding based framework for high quality peer-to-peer live video streaming.

In recent years, Random Network Coding (RNC) has emerged as a promising solution for efficient Peer-to-Peer (P2P) video multicasting over the Internet. This probably refers to this fact that RNC noticeably increases the error resiliency and throughput of the network. However, high transmission overhead arising from sending large coefficients vector as header has been the most important challenge of the RNC. Moreover, due to employing the Gauss-Jordan elimination method, considerable computational complexity can be imposed on peers in decoding the encoded blocks and checking linear dependency among the coefficients vectors. In order to address these challenges, this study introduces MATIN which is a random network coding based framework for efficient P2P video streaming. The MATIN includes a novel coefficients matrix generation method so that there is no linear dependency in the generated coefficients matrix. Using the proposed framework, each peer encapsulates one instead of n coefficients entries into the generated encoded packet which results in very low transmission overhead. It is also possible to obtain the inverted coefficients matrix using a bit number of simple arithmetic operations. In this regard, peers sustain very low computational complexities. As a result, the MATIN permits random network coding to be more efficient in P2P video streaming systems. The results obtained from simulation using OMNET++ show that it substantially outperforms the RNC which uses the Gauss-Jordan elimination method by providing better video quality on peers in terms of the four important performance metrics including video distortion, dependency distortion, End-to-End delay and Initial Startup delay.

Efficient P2P Live Video Streaming Over Hybrid WMNs Using Random Network Coding

As random network coding (RNC) considerably increases the network throughput, it has been of great interest for video streaming over wireless mesh networks (WMNs). However, mobile video users suffer from high transmission overhead due to the transmission of large coefficient vectors as headers and an excessive imposed decoding computational complexity due to using the Gauss–Jordan elimination method in RNC. This complexity cannot be supported by the embedded mobile processors. To overcome these limitations, this study analyses the impact of applying a method that simplifies RNC requirements on WMNs. This method is based on the generation of a full rank coefficients matrix without any linear dependency among its vectors. Nodes encapsulate one instead of

A new Variable Error Metric adaptive beamforming Algorithm for smart antenna systems

n

Promoting Wired Links in Wireless Mesh Networks: An Efficient Engineering Solution

n coefficients entries into a packet which leads to very low transmission overhead. Receivers can obtain the inverted coefficients matrix by performing very few arithmetic operations. Consequently, wireless nodes experience very low decoding computational complexity eliminating the need for powerful processors and high battery energy sources. The wireless medium is also less occupied and the transmission processes are shorter. Simulation results in the OMNeT++ framework depict that the applied method provides high video quality on the nodes by addressing the mentioned challenges, even if high mobility rates exist in the WMN.

Performance evaluation of routing protocols in live video streaming over wireless mesh networks

Directional antennas are largely employed in wireless networks due to their capability of increasing spatial reuse of the wireless channel with respect to the classical omnidirectional systems. In this context. the use of Smart Antenna Systems (SAS) are providing a strong increasing impact in digital wireless communication systems. Because of their many benefits, this kind of systems are extremely used especially in pervasive network environments such as Mobile Ad hoc Networks (MANET). However, almost of the whole of existing network simulators use omnidirectional antennas on nodes, and in many cases, do not provide a support for asymmetrical and directional communications. In view of this, we intend to enhance Omnet++ network simulator features by designing a new switched beam smart antenna model for providing a support for directional communications. Our proposed model simulates the basic operation of a Phased Array System also exploiting a very simple algorithm for modeling power management in the channel in order to provide an asymmetrical communication behavior.

GAZELLE: An Enhanced Random Network Coding Based Framework for Efficient P2P Live Video Streaming Over Hybrid WMNs

The use of adaptive antenna systems enables the improvement of the overall wireless network capacity, especially in Mobile Ad hoc Networks (MANET) environments in which the quality of the communication is closely related to the Signal-to-Noise-Ratio (SNR) measured in the channel. Unfortunately, most of used adaptive algorithms such as Least Mean Square (LMS) and Constant Modulus Algorithm (CMA), because are strongly related to the step size value and to the error metric estimation, usually present a speed convergence problem. In this paper, a new Variable Error Metric (VMA) adaptive Algorithm is proposed in order to limit the level of dependency between the algorithms and step size also reducing the slowing effect introduced by Mean Square Error (MSE) criterion used for example by LMS algorithm.

A sectorized directional MAC proposal for mitigating deafness and energy consumption in mobile ad hoc networks

Simulations in complex network scenario environments such as Adaptive Beamforming Networks (ABFN), are very expensive in terms of computational costs. To reduce the overall computational burden, we propose to integrate Omnet++ simulator with Matlab in order to provide a co-simulation model for allowing an efficient communication system that is able to emulate high complexity simulation contexts.