Hany M. Elsayed

Performance of Fast and Gigabit Ethernet in networked control systems

In this paper, the use of Fast and Gigabit Ethernet in networked control systems is tested. Real-time traffic and non-real time traffic are integrated without changing the IEEE 802.3 protocol packet format. In a mixed traffic industrial environment, it is found that standard Gigabit Ethernet switches succeed to meet time constraints that Fast Ethernet failed to meet

Ethernet-Based Car Control Network

The use of networks for communication between electronic control units has increased in car industry over the last two decades. Several types of networks were developed for this purpose. In this study, Ethernet at gigabit speed is tested as a network for such system. The use of Ethernet helps integrating real-time control functions and non-real-time entertainment functions. Two main scenarios were simulated using OPNET. The fist one simulates pure control networks on board of a moving vehicle. The second scenario is the same as the first one with an added video load to simulate on-board entertainment. Both simulations were successful, as the end-to-end delays were below the maximum round-trip delays required by the system

Gigabit Ethernet for redundant networked control systems

In this paper, the use of fast and Gigabit Ethernet in advanced networked control systems is studied. Redundant control node scenario is the key factor for minimum down-time. Ethernet 802.3 protocol is tested without modification in frame format. Gigabit Ethernet succeeded to absorb the control traffic of several working machines while fast Ethernet could not.

Effect of node distributions on lifetime of Wireless Sensor Networks

Wireless Sensor Networks has recently become an attractive research topic due to the rapidly growing field of applications. This paper focuses on prolonging network lifetime by investigating different node deployments including both geometric and uniform. Geometric distributions resulted in a 35.6% increase in lifetime as opposed to random distributions. Furthermore, different sink locations were examined. The optimum sink location introduced a considerable lifetime elongation compared to the previously used location.

Fault-tolerant networked control systems under varying load

In this paper, a simulation study is made to test the fault tolerant ability of networked machines. This ability is introduced by reallocating loads in case of controller failure. Also, the increase in machine speed for higher production, is considered. The maximum speed of operation of individual machines and fault tolerant production-lines, is studied. All machine networks of this study are built on-top-of switched Gigabit Ethernet in star topology.

Fault tolerant two-level pyramid networked control systems

In this paper, a pyramid control hierarchy is proposed. It is based on the presence of a supervisor controller on top of separate controller nodes. A simulation study is conducted to test the functionality of the system. The proposed model is an enhancement of machine modeled in form of networked control systems (NCS). Two models are tested: one supervisor/two sub-controllers, one supervisor/three sub-controllers. All possible combinations of supervisor-controller intercommunication are tested. Also, all supervisor/controller inter-changeability possibilities are taken into consideration. Results are illustrated and discussed. Recommendations are drawn out. All machine models of this study are built using switched gigabit Ethernet in star topology

Lifetime optimization in hierarchical wireless sensor networks

Wireless sensor networks is a voracious field for research, especially after the great advances in MEMS based sensors. In this paper, environmental monitoring applications are considered where data may be continuously reported with the possibility of urgent alarming if necessary. Hierarchical architecture of the network is assumed in order to overcome the problem of energy constrained sensors. Two algorithms are proposed with the purpose of network lifetime elongation and the maximization of the use of the available energy. The first algorithm is a modification for LEACH-C to enhance its performance. It results in a 25% longer lifetime. The second algorithm is an energy efficient method to ensure full coverage of the network as long as sensors are still working. This achieves 32% longer lifetime than LEACH-C.

The Use of Ethernet for Single On-board Train Network

The use of Ethernet protocol for railway vehicle on-board networks is considered. It is shown that a single Ethernet network can carry real-time control data, thus replacing existing train control networks. In addition, this network can also carry entertainment data for passengers as well as data coming from mobile wireless devices carried on-board. OPNET simulations are used to estimate the maximum allowable entertainment traffic that can be carried by the network while satisfying the real-time constraints of the control traffic.

Wireless Vehicle Communication for Traffic Control in Urban Areas

This paper introduces the idea of using the stigmergic approach to solve traffic problems in congested urban areas and focuses on the communications aspect of the problem. V2I and I2V are based on IEEE 802.11 standard. The urban area is equipped with access points that are wired to a central node. The number of packets lost is investigated at different vehicle speeds as well as different I2V broadcast rates. The best broadcast rate is found in order to reduce the packets lost irrespective of vehicle speed

Effect of hamming coding on WSN lifetime and throughput

Wireless Sensor Networks has become an attractive field of research due to its wide range of applications. This paper focuses on improving network throughput without affecting the lifetime. It shows that the use of the Hamming code has a negligible effect on network lifetime irrespective of the SNR. In contrast, the CRC with retransmissions reduces the lifetime by 37.3% compared to the uncoded system. It is also proven that using the Hamming code increases system throughput when compared to the use of CRC. High-rate Hamming codes have a higher throughput than low-rate Hamming codes over network lifetime. Both AWGN and Rayleigh fading channels are considered. If the Network Master is used as a repeater, it is found that this generally increases network lifetime. Furthermore, at low SNR, system throughput in the case of high-rate Hamming codes is increased. The above results are shown both for fixed data and fixed frame schemes.