Traffic signals play an important role in controlling and coordinating the traffic movement in cities especially in urban areas. As the traffic is exponentially increasing in cities and the pre-timed traffic light control is insufficient in effective timing of the traffic lights, it leads to poor traffic clearance and ultimately to heavy traffic congestion at intersections. Even the Emergency vehicles like Ambulance and Fire brigade are struck at such intersections and experience a prolonged waiting time. An adaptive and intelligent approach in design of traffic light signals is desirable and this paper contributes in applying fuzzy logic to control traffic signal of single four-way intersection giving priority to the Emergency vehicle clearance. The proposed control system is composed of two parallel controllers to select the appropriate lane for green signal and also to decide the appropriate green light time as per the real time traffic condition. Performance of the proposed system is evaluated by using simulations and comparing with pre-timed control system in changing traffic flow condition. Simulation results show significant improvement over the pre-timed control in terms of traffic clearance and lowering of Emergency vehicle wait time at the intersection especially when traffic intensity is high.
A compact ultra-wideband antenna (UWB) is presented in this paper for WLAN, WiMAX, LTE and Smart grid applications. The proposed antenna comprises a circular patch and rectangular slot in center of circular patch and apart from this it also consists of four small rectangular slots around circular patch to provide wideband. The antenna is fabricated onto Rogers R03003 substrate with an overall dimension of 47X47 mm 2 . The substrate has dielectric constant of 3 and thickness of 1.6 mm. The simulated experiment shows that the proposed antenna achieves good impedance matching an operating bandwidth of 2.5-8.2 GHz (106.5%) and 10-15 GHz (40%) that covers the lower UWB and higher UWB band. Thus it covers WLAN 5.2/5.8 GHz band, WiMAX 2.5/3.5/5.5 GHz band and LTE 2.5-2.69 GHz band. The gain of this antenna varies between 2-3 dBi for most of the frequency band and therefore the proposed antenna is suitable for being used in UWB communication applications.
Mobile ad hoc network is an infrastructure-less network, that consist of mobile nodes, with the ability to communicate with each other without any centralized unit. The main features of MANETs are, wireless medium, dynamic topology, distributed cooperation, vulnerable to many security attacks and data loss because of the mobility of nodes.Many routing protocols have been developed for MANET, but ad hoc on Demand Distance Vector (AODV) routing protocol is preferred as the best routing protocol for MANET, because it minimizes the routing overhead more than the other protocols and hence improves the performance of the network. In this article, we have analyzed and evaluated the performance of Nakagami propagation loss model and Friis propagation loss model under different mobility scenario at different speeds to measure the performance parameter such as Packet Delivery Ratio (PDR), Throughput and Packet loss, the routing protocol used in are research is AODV.
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