This paper presents AGA-MAC: an adaptive geographic any cast medium access control (MAC) protocol for wireless sensor networks (WSNs). The aims at reducing the sleep-delay problem of asynchronous preamble-based MAC protocols by selecting opportunistically next relay node from a set candidates. size Forwarding Candidate Set (FCS) is influenced threshold parameter in our protocol. In order to outperform other existing protocols, we analyze effect different network densities, and values...

This paper presents a method for federating disjoint segments of Wireless Sensor Networks (WSNs) in the presence unbalanced traffic. The approach relies on an Unmanned Aerial Vehicle (UAV) message ferrying. Network disconnections compromise system operation, ergo alternative to mitigate is important extend network lifetime. In our work, UAV becomes data mule, carrying physically packets across partitions assure connection. presented this article goes beyond previous work by taking into...

Wireless sensor networks employ duty-cycles to save energy, with the cost of enlargement end-to-end latency. Cross-layer protocols that use anycast medium access control achieve latency reduction in asynchronous duty-cycled wireless (WSNs). A series strobed preambles is sent order rendezvous next relay, selected from a forwarding candidate set (FCS). This paper proposes PAX-MAC: Pramble Ahead Medium Access Control. It novel protocol for low packet propagation WSNs. In PAX-MAC, propagate...

This paper proposes a distributed measuring system based on wireless sensor networks (WSN) employed to estimate plant water-content in agricultural fields. The WSN is present crop field order measure environmental variables, like soil moisture. Water-content obtained by the attenuation of network communication signal. need for measurements parameters pointed-out and mathematical model radio-wave propagation through vegetation developed. used water-content. Experimental results are also presented.

This paper presents a novel cross-layer anycast medium access control (MAC) protocol for wireless sensor networks (WSNs) based on advanced preamble propagation and geographic routing. The aims at reducing the sleep-delay problem, common in asynchronous preamble-based MAC protocols. When packet is ready to be transmitted, differently from other state-of-the-art protocols, sequence propagated advance several hops before release. So, simultaneous of signaling obtained. number nodes Forwarding...

Wireless sensor networks (WSN) and many other wireless communication systems utilize the spectrum frequency of 2.4 GHz. Radio interference, intentional or not, is a serious threat to availability services major cause performance losses in networks. This paper evaluates behavior WSN under interference real-world scenarios, such as WSNs, WLANs, Bluetooth microwave ovens. Moreover, evaluated prototype multi-radio node an alternative for reducing coexistence problems. Results shown that delivery...

This paper presents a new routing protocol for opportunistic networks based on sociological movement model. In this model, the mobile nodes have tendency to visit fixed places frequently. Our approach recognizes encounter places, called hubs, and employs them as base elements procedure. Nodes visiting frequently two or more hubs are considered carriers used data mule message transport. After setting up infrastructure, tables constructed in hubs. When should be routed, it is sent hub and,...

This paper presents GB-MAC, an asynchronous cross-layer medium access control protocol. Several MAC protocols suffer from the sleep-delay problem which causes a large latency in multi-hop communications. In our approach, we create backbone composed by nodes with short active-sleep cycles to ensure fast relay of messages and sink node. About 15% are recruited form backbone. Moreover, protocol is order avoid complexity arising constant time synchronizations. Simulations have shown that low all...

This paper presents an analytical model for anycast asynchronous preamble-based medium access control (MAC) protocols. Asynchronous MAC protocols are widely used in Wireless Sensor Networks (WSN). An important drawback of these is the sleep-delay phenomenon, which may impose high communication latency. In order to tackle this shortcoming, concept anycast, i.e., explore opportunistic path redundancy employed, instead selecting a unique next hop. Existing approaches employ arbitrary rules...

This paper proposes a distributed measuring system based on wireless sensor networks (WSN) employed to estimate vegetation water content in agricultural fields. A WSN deployed along the whole field permits measure and map soil, air plant variables transmit these data, by small radios, central computer. Water is obtained attenuation of network communication signals (RF), without use any specific sensor. The need measurements crop parameters pointed out. mathematical model radio wave...

Redes de Sensores Sem Fio (RSSF) usam ciclos trabalho como estratégia para economizar energia. O atraso propagação (sleep-delay) é uma consequência negativa desse modo operação, aumentando a latência fim-a-fim. Apresenta-se aqui o Split-MAC: um protocolo assíncrono baixa energia e reduzida RSSFs. Ele reúne funções controle acesso ao meio roteamento, emprega estratégias obter latência: comunicação anycast, esquema reserva canal transmitir dados maneira encadeada transmissão simultânea...