1,720,971 research outputs found
Dynamic forward error correction algorithm over IP network services for ITU-T G.722.2 codec
No full textIn this paper, we present the design of a new packet loss concealment (PLC) algorithm based on Dynamic Forward Error Correction (FEC) to improve speech quality degradation caused by packet losses. It is to be implemented for the standard ITU-T AMR-WD G.722.2 codec. The performance proposed scheme is compared with the original method embedded in the standard ITU-T G.772.2. To evaluate its performance, the perceptual evaluation of speech quality (PESQ) and enhanced modified bark spectral distortion (EMBSD) tests under a variety of packet loss rates are used and the obtained results prove that the proposed PLC based Dynamic FEC is better than the concealment method embedded in the ITU-T G.722.2 for speakers (female and male). The performance measures confirm that our PLC method based Dynamic FEC is superior than the
one embedded in the standard ITU-T G.722.2
Joint Voice/Video Retry Limit Adaptation for On-Demand Streaming over WiFi Networks
Get PDFThis letter proposes a fast retry limit adaptation algorithm for the 802.11e distributed networks. Different from existing solutions, which manage a unique access category, the presented method jointly estimates the retry limits associated with both voice and video packets. The algorithm that operates in saturated and non-saturated traffic conditions is validated adopting an 802.11n physical layer and comparing its performance with a proper extension of an existing solution
A Network Coding Approach for Reliable SDN Based UAV Networks
No full textInternational audienceRecently, the integration of unmanned Aerial Vehicles (UAV) in Software-Defined Networking (SDN) based environments has seen an increasing research turnout as it allows a logical centralization of the control function while enhancing Information Technology (IT) management. This paper focuses on the use of Network Coding (NC) to secure the exchanged data between the UAVs where we consider the deployment of an SDN-based UAV architecture in a logical environment. We also consider the integration of NC in a UAV-SDN-based architecture to reduce the number of packet retransmissions and improve network reliability in lossy networks. To further secure data integrity in our system, we propose a pollution attack detection method as a tool to identify and block malicious packets from accessing the network. We assume that the UAVs are powerful enough to perform all encoding and decoding operations during communication
Securing UAV Communication: Authentication and Integrity
Get PDFRecent technological advancements have seen the integration of unmanned aerial networks (UAVs) into various sectors, from civilian missions to military operations. In this context, ensuring security, precisely authentication, is essential to prevent data theft and manipulation. A Man-in-the-Middle attack not only compromises network integrity but also threatens the original data, potentially leading to theft or alteration. In this work, we proposed an authentication method to secure UAV data exchange over an insecure communication channel. Our solution combines Diffie-Hellman (DH) key exchange and Hash-based Message Authentication Code (HMAC) within ROS communication channels to authenticate exchanged UAV data. We evaluated our method by measuring transmission time and simulating key tampering, finding acceptable performance for DH key sizes below 4096 bits but longer times for larger sizes due to increased complexity. Both drones successfully detected tampered keys, affirming our method\u27s efficacy in protecting UAV communication. However, scalability challenges in resource-constrained environments warrant further research
A Cooperative NOMA User Pairing in UAV-Based Wireless Networks
Get PDFNOMA (non-orthogonal multiple access) will be seen as a promising technology
for enhancing spectrum efficiency in future cellular networks. The use of
unmanned aerial vehicle (UAV) Amplify-and-Forward (AF) relaying as a moving
access point or BS, on the other hand, has emerged as a potential solution to
wireless networks' high traffic demands. In this paper, we study joint user
pair and resource allocation-based distance to optimize fair throughput in a
downlink scenario, which concentrates on UAV-aided communication from different
wireless-powered nodes. Several transmission methods are proposed, including
NOMA as well as UAV cooperative relaying and two representative node-pairing
strategies. The simulation results illustrate that the proposed user pairing
strategies for cooperative NOMA and UAV-based cellular networks enhance
downlink transmission performance and ensure optimum use of power and bandwidth
resources.Comment: 5 pages, 4 figure
Subspace Coding for Error Control and Interference Mitigation in Routing Solutions with Cooperative Destination Nodes
Get PDFRandom Linear Network Coding (RLNC) is a transmission scheme that opts for
linear combinations of the transmitted packets at a subset of the intermediate
nodes. This scheme is usually considered when Network Coding (NC) is desired
over non-coherent networks. In order to integrate error correction in RLNC,
subspace codes have been proposed. The codewords in those codes are unchanged
under rank-preserving row operations, making them convenient for RLNC. In this
paper, we investigate the use of those codes for the interference channel in a
system model consisting of an array of SISO communication systems with
cooperative destination nodes. This system model is deemed as a simplified
model of a network with a routing based transmission scheme. Results have
indicated that the use of subspace codes have allowed for better performance in
terms of the decoding failure probability.Comment: (5 pages, 5 figures, conferenc
Illuminating Networks: Enhancing Visible Light Communication with Physical-Layer Network Coding (PNC-VLC Scheme)
Get PDFWireless communications using light waves are called visible light communication. A technique called Physical-layer Network coding allows several users to communicate simultaneously over the same channel in a distributed space-time Coding scheme. Herein, we report a new PNC-VLC one-to-many scheme using physical-layer network coding in VLC system for enhancing throughput by boosting data transmission at relay nodes. We develop an integrated PNC-VLC framework including physical-layer signal processing algorithms and medium access control approaches. Our proposed technique is then modelled mathematically and compared with some of the VLC and PNC-VLC schemes under various channel conditions and scenarios. Our investigation revealed that our proposed technique performed better than traditional PNC schemes in achieving better Bit Error Rate performance in different channe
Robust and Secure Speech Based on Elliptic Curve Cryptography for WB G.722.2
No full textInternational audienceElliptic Curve Cryptographic (ECC) systems are now increasingly used in protocols using public key cryptography, as it allows to significantly reduce the size of the keys used compared to other cryptographic systems such as RSA (Ron Rivest, Adi Shamir and Leonad Adelman). ECC is based on Elliptic Curve (EC) theory, for creating faster, smaller, and more efficient cryptographic schemes. This paper presents an encryption scheme for AMR-WB ITU-T G.722.2 speech based on ECC for securing transmitted speech signals. The implementation of ECC is carried out by transforming the coded speech into an affine point on the elliptic curve, over a finite field. The proposed cryptosystem is evaluated by including waveform and spectrogram analysis, Enhanced Modified Bark Spectral Distortion (EMBSD) and Wideband Perceptual Evaluation of Speech Quality (WB-PESQ) for objective testing and Mean Opinion Score (MOS) for its subjective counterpart in order to confirm the efficiency of our proposed method in terms of security and privacy
A Cooperative NOMA User Pairing in UAV-Based Wireless Networks
No full textInternational audienceNOMA (Non-Orthogonal Multiple Access) is deemed a promising technology for enhancing spectrum efficiency in future cellular networks. The use of unmanned aerial vehicle (UAV) Amplify-and-Forward (AF) relaying as a moving access point or BS, on the other hand, has emerged as a potential solution to high traffic demands in wireless networks. In this paper, we study joint user pairing and resource allocationbased distance to optimize fair throughput in a downlink scenario, with a focus on UAV-aided communication from different wireless powered nodes. Several transmission methods are adopted, including NOMA as well as UAV cooperative relaying along with two representative nodepairing strategies. The simulation results illustrate that the proposed user pairing strategies for cooperative NOMA and UAV-based cellular networks enhance downlink transmission performance and ensure optimum use of power and bandwidth resources
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