Artificial lighting allows humans to be active at night, but has many unintended consequences, including interference with ecological processes, disruption of circadian rhythms and increased exposure to insect vectors of diseases. Although ultraviolet and blue light are usually most attractive to arthropods, degree of attraction varies among orders. With a focus on future indoor lighting applications, we manipulated the spectrum of white lamps to investigate the influence of spectral composition on number of arthropods attracted. We compared numbers of arthropods captured at three customizable light-emitting diode (LED) lamps (3510, 2704 and 2728 K), two commercial LED lamps (2700 K), two commercial compact fluorescent lamps (CFLs; 2700 K) and a control. We configured the three custom LEDs to minimize invertebrate attraction based on published attraction curves for honeybees and moths. Lamps were placed with pan traps at an urban and two rural study sites in Los Angeles, California. For all invertebrate orders combined, our custom LED configurations were less attractive than the commercial LED lamps or CFLs of similar colour temperatures. Thus, adjusting spectral composition of white light to minimize attracting nocturnal arthropods is feasible; not all lights with the same colour temperature are equally attractive to arthropods.

Wireless sensor networks are collections of autonomous devices with computational, sensing and wireless communication capabilities. Research in these networks has been growing steadily in the past few years given the wide range of applications that can benefit from such a technology. In this paper, the development of a highly modular and miniaturized wireless platform for sensor networks is described. The system incorporates a radio transceiver (operating in the 2.4 GHz ISM Band) with embedded protocol software to minimize power consumption and maximize data throughput. Additional input capability for sensor and actuator integration can be incorporated seamlessly due to the modular nature of the system. The total system is packaged in a modular 25mm cubed form factor.

Abstract. Nodes in a wireless network transmit messages through a shared medium. Thus, a Media Access Control (MAC) protocol is necessary to regulate and coordinate medium access. For some application areas it is necessary to have a deterministic MAC protocol which can give guarantees on message delay and channel throughput. Schedule based MAC protocols, based on time synchronization among nodes, are currently used to implement deterministic MAC protocols. Time synchronization is difficult and costly, especially in energy constrained sensor networks. In this paper the f-MAC protocol is presented which can give guarantees regarding message delay and channel throughput without the requirement of time synchronization among nodes. The various trade-offs of f-MAC are analysed and discussed and application areas that would benefit from f-MAC are presented.

For the long-term deployment of wireless sensor networks, energy efficient MAC protocols are necessary. The transceiver of a sensor node should only consume energy while actively taking part in communication. Energy consumption in idle mode should be avoided as much as possible. In this paper it is shown how application layer knowledge in the form of flow specifications can be used to improve the energy properties of a MAC protocol. A new protocol, named £-MAC, is proposed and evaluated through simulations.