Salwa H. El Ramly

Bio: Salwa H. El Ramly is an academic researcher from Ain Shams University. The author has contributed to research in topics: Bit error rate & Routing protocol. The author has an hindex of 6, co-authored 24 publications receiving 100 citations.

PR-LEACH: Approach for balancing energy dissipation of LEACH protocol for wireless sensor networks

Abstract: Wireless sensor networks are composed of hundreds or even thousands of sensor nodes which have limited energy. Energy consideration is a very critical issue for designing routing protocols. This paper discusses a common clustering protocol, called LEACH, and improves cluster-head selection criteria. LEACH selects cluster-heads based on random probability, while the proposed algorithm considers the sensor nodes residual energy in order to balance energy dissipation among all of the nodes to extend network lifetime as one unit to minimize dead-spots. MATLAB simulation shows that the proposed energy consideration protocol which is called Percentage LEACH (PR-LEACH), provides better performance compared to LEACH protocol.

Securing Modern Voice Communication Systems using Multilevel Chaotic Approach

Abstract: this paper, we present a new voice encryption for voice communication system. It is based on permutation and substitution of voice samples using transform domains and secret keys in time. To increase the security we design the system such that it is multilevel in the sense that two chaotic maps are used. This provides the encrypted signal with a high degree of confidence. The Arnold cat map is applied to a permutation of the samples, The Henon map is employed in key generation to generate mask keys to be used in the substitution process. The results show that the encryption system provides the speech signal with a high degree of confidence, key sensitivity and high quality recovered signal. Total key space for the proposed encryption system is larger than ( 2 425 ), which is large enough to protect the encrypted signal against attack. Keywordsencryption, Henon map, Arnold cat map, Permutation, Substitution.

Securing digital voice communication using non-autonomous modulated chaotic signal

Abstract: In this paper, we present an encryption approach for voice communication systems based on direct chaotic modulation (non-autonomous modulation), in which voice is injected into one variable of the master system (using either Lorenz chaotic flow or Qi hyperchaotic flow) without changing the value of any control parameter. This approach is based on the change of chaotic signal by injecting voice samples into one variable in chaotic system and hence generating a new chaotic signal. The voice signal is then extracted from the chaotic signal in the receiver side. Furthermore, we use a high dimension chaotic flow which increases the security of the encrypted signal. Non-autonomous modulation technique is suitable for secure real-time applications. We also presented a comparative study between the two approaches with their conventional chaotic masking counterparts. Experimental results show that non-autonomous methods give better performance than their chaotic masking counterparts when they are analyzed against Signal-to-Noise-Ratio (−38.55 dB vs. 38.51 dB and 59.22 dB vs. 58.11 dB), Segmental signal-to-Noise-Ratio (38.91 dB vs. 38.84 dB and 54.20 dB vs. 53.16 dB), Log-Likelihood Ratio (0.88 vs. 0.80 and 1.59 vs. 1.50), and Correlation Coefficient Analysis (0.0345 vs. 0.021 and 0.0002 vs. 0.01012). Statistical analyses show that the second proposed approach has the best results for the encrypted signal. Modifying conventional chaotic approaches increases the security of the encryption system.

Novel hybrid soft-hard demodulation schemes for RQD constellation

Abstract: Rotated constellation with Q-delay (RQD) is a new modulation scheme adopted by some wireless standards including the second generation of the digital video broadcasting for terrestrial (DVB-T2) system. This scheme offers significant improvement over unrotated modulation in terms of bit error rate (BER) performance due to its signal space diversity. In this paper, we present four novel computationally efficient demodulation schemes with hybrid soft-hard outputs used in hard demapping of data. The main idea is to take advantage of the unique projections the rotated cells have in the RQD system. The proposed schemes reduce the number of log likelihood ratio (LLR) computations. One proposed scheme gives the same BER performance as traditional LLR while reducing the computational complexity by 34% at SNR = 20 dB. Another scheme reduces the computations by 25% independent of the SNR level. The other two schemes offer a tradeoff between computational complexity and power efficiency.

An Arnold Cat Map-Based Chaotic Approach for Securing Voice Communication

Abstract: We present four encryption approaches for voice communication systems by combining Arnold cat map with either Henon or modified Henon or Unified or Lorenz chaotic maps. These approaches depend on permuting and substituting voice samples using transform domains and secret keys in time. We use two levels of chaotic maps to increase the security of the encrypted signal. We first apply Arnold cat map to permute the voice samples, then we apply either Henon or modified Henon or Unified or Lorenz chaotic maps to generate the mask key and hence substitute the permuted samples. We also present a comparative study between these approaches. Experimental results show that modifying conventional chaotic approaches from one level chaotic map to two levels chaotic map increases the key space of the encryption system.

Narrowband Internet of Things (NB-IoT): From Physical (PHY) and Media Access Control (MAC) Layers Perspectives

Abstract: Narrowband internet of things (NB-IoT) is a recent cellular radio access technology based on Long-Term Evolution (LTE) introduced by Third-Generation Partnership Project (3GPP) for Low-Power Wide-Area Networks (LPWAN). The main aim of NB-IoT is to support massive machine-type communication (mMTC) and enable low-power, low-cost, and low-data-rate communication. NB-IoT is based on LTE design with some changes to meet the mMTC requirements. For example, in the physical (PHY) layer only single-antenna and low-order modulations are supported, and in the Medium Access Control (MAC) layers only one physical resource block is allocated for resource scheduling. The aim of this survey is to provide a comprehensive overview of the design changes brought in the NB-IoT standardization along with the detailed research developments from the perspectives of Physical and MAC layers. The survey also includes an overview of Evolved Packet Core (EPC) changes to support the Service Capability Exposure Function (SCEF) to manage both IP and non-IP data packets through Control Plane (CP) and User Plane (UP), the possible deployment scenarios of NB-IoT in future Heterogeneous Wireless Networks (HetNet). Finally, existing and emerging research challenges in this direction are presented to motivate future research activities.

Mobile sink-based energy efficient cluster head selection strategy for wireless sensor networks

Abstract: Energy efficient routing protocol is the requirement of today’s wireless sensor networks. Various protocols have been developed in order to create an energy efficient wireless sensor network, but still some loopholes exist in this domain and energy hole is one of them. Energy hole refers to the early energy diminution of those nodes that are near to the sink. This study introduced a mobile sink based energy aware clustering mechanism to enhance the lifetime of the network by overcoming the issue of energy holes. In proposed work, the network is initially divided into the number of rectangular regions and each region is comprised of one cluster head (CH). The nature-inspired firefly optimization algorithm is used to select cluster heads where residual energy, average node to node distance and distance from the node to sink are the decisive parameters of the process. The sink moves in the observing field after estimating the centroid location of the CHs. The performance of the proposed work is compared with the LEACH, LEACH-GA, A-LEACH, MIEEPB, and MSIEEP by using Matlab simulation platform. The result section represents the proficiency of the proposed MSECA protocol over traditional techniques in term of network lifetime, packet delivery ratio and packet delay.