TCP CERL+: revisiting TCP congestion control in wireless networks with random loss

Wireless Networks - In this paper, we analyze the performance of wireless networks subject to random loss. In this regard, we revisit our TCP Congestion Control Enhancement for Random Loss (CERL)...     

Home Security System Using Wireless Sensors Network

Wireless Personal Communications - In this paper, we propose a smart and robust home security system. This is for intrusion detection along with a proprietary Android application. Intruder-Spi...     

Improving Throughput in Lossy Wired/Wireless Networks

Wireless communication is more prone to random loss than wired communication because of noise and mobility. Over years researchers have developed TCP variants that do not decrease the send window when random loss arises. Years ago it was introduced TCP CERL algorithm that proved to present a high performance compared to other protocols. Here, we test CERL assuming two-way transmission of relatively heavy load and compare with TCP BIC, TCP NewReno, TCP Westwood+, TCP NewJersey and TCP Illinois. Simulation Results show that TCP CERL gains a 145%, 137%, 120%, 97% and 125% throughput improvement over New Reno, Bic, Westwood+, New Jersey and Illinois, respectively.

     

Laser backscattered from partially convex targets of large sizes in random media for E-wave polarization

The characteristics of a radar cross section (RCS) of partially convex targets with large sizes up to five wavelengths in free space and random media are studied. The nature of the incident wave is an important factor in remote sensing and radar detection applications. I investigate the effects of beam wave incidence on the performance of RCS, drawing on the method I used in a previous study on plane-wave incidence. A beam wave can be considered a plane wave if the target size is smaller than the beam width. Therefore, to have a beam wave with a limited spot on the target, the target size should be larger than the beam width (assuming E-wave incidence wave polarization. The effects of the target configuration, random medium parameters, and the beam width on the laser RCS and the enhancement in the radar cross section are numerically analyzed, resulting in the possibility of having some sort of control over radar detection using beam wave incidence.     

Routing Using Genetic Algorithm in a Wireless Sensor Network

In this paper we probe the routing algorithm that maximizes the quality of the network. In this regard, we present various scenarios for comparisons among different routing algorithms in a wireless sensor network. Using simulations conducted in NS-2, we compare the performance of genetic algorithm (GA) to the Dijkstra algorithm, Ad hoc On-Demand Distance Vector (AODV), GA-based AODV Routing (GA-AODV), grade diffusion (GD) algorithm, directed diffusion algorithm and GA combined with the GD algorithm. We assume the presence of faulty nodes and work on finding out the performance that enhances the lifespan of the sensor network. In this regard, we have simulated routing algorithms while considering faulty nodes up to 50% of the functioning nodes. Nodes are considered to be dynamic and we assumed different mobility speeds of the nodes. Our results demonstrate that GA can be used in different network configurations as it shows a better performance in the wireless sensor network.

     

TCP CERL: congestion control enhancement over wireless networks

In this paper, we propose and verify a modified version of TCP Reno that we call TCP Congestion Control Enhancement for Random Loss (CERL). We compare the performance of TCP CERL, using simulations conducted in ns-2, to the following other TCP variants: TCP Reno, TCP NewReno, TCP Vegas, TCP WestwoodNR and TCP Veno. TCP CERL is a sender-side modification of TCP Reno. It improves the performance of TCP in wireless networks subject to random losses. It utilizes the RTT measurements made throughout the duration of the connection to estimate the queue length of the link, and then estimates the congestion status. By distinguishing random losses from congestion losses based on a dynamically set threshold value, TCP CERL successfully attacks the well-known performance degradation issue of TCP over channels subject to random losses. Unlike other TCP variants, TCP CERL doesn’t reduce the congestion window and slow start threshold when random loss is detected. It is very simple to implement, yet provides a significant throughput gain over the other TCP variants mentioned above. In single connection tests, TCP CERL achieved an 175, 153, 85, 64 and 88% throughput gain over TCP Reno, TCP NewReno, TCP Vegas, TCP WestwoodNR and TCP Veno, respectively. In tests with multiple coexisting connections, TCP CERL achieved an 211, 226, 123, 70 and 199% throughput improvement over TCP Reno, TCP NewReno, TCP Vegas, TCP WestwoodNR and TCP Veno, respectively.