Survey of the State-of-the-Art in Flash-based Sensor Nodes

Real-Time Communications in Wireless Sensor Networks

Next Generation Mobile Networks and Ubiquitous Computing ◽

10.4018/978-1-60566-250-3.ch008 ◽

2010 ◽

pp. 69-78

Author(s):

Isabelle Augé-Blum ◽

Fei Yang ◽

Thomas Watteyne

Keyword(s):

Wireless Sensor Networks ◽

Sensor Networks ◽

Real Time ◽

State Of The Art ◽

Communication Protocols ◽

The State ◽

Sensor Nodes ◽

Wireless Sensor ◽

Future Trends ◽

Wireless Links

This chapter presents the state-of-the-art of real-time communication in the challenging topic of Wireless Sensor Networks (WSNs). In real-time communication, the duration between the event which initiates the sending of a message, and the instant this message is received must be smaller than a known delay. Because topologies are extremely dynamic and not known priori, this type of constraint is very hard to meet in WSNs. In this chapter, the different communication protocols proposed in the literatures, together with their respective advantages and drawbacks, are discussed. We focus on MAC and routing because they are key layers in real-time communication. As most existing protocols are not suitable under realistic constraints where sensor nodes and wireless links are unreliable, we give, at the end of this chapter, some insights about future trends in designing real-time protocols. We hope to give the reader an overview of recent research works in this complex topic which we consider to be essential in critical applications.

Download Full-text

Real-Time Communications in Wireless Sensor Networks

Wireless Technologies ◽

10.4018/978-1-61350-101-6.ch107 ◽

2012 ◽

pp. 120-129

Author(s):

Isabelle Augé-Blum ◽

Fei Yang ◽

Thomas Watteyne

Keyword(s):

Wireless Sensor Networks ◽

Sensor Networks ◽

Real Time ◽

State Of The Art ◽

Communication Protocols ◽

The State ◽

Sensor Nodes ◽

Wireless Sensor ◽

Future Trends ◽

Wireless Links

This chapter presents the state-of-the-art of real-time communication in the challenging topic of Wireless Sensor Networks (WSNs). In real-time communication, the duration between the event which initiates the sending of a message, and the instant this message is received must be smaller than a known delay. Because topologies are extremely dynamic and not known priori, this type of constraint is very hard to meet in WSNs. In this chapter, the different communication protocols proposed in the literatures, together with their respective advantages and drawbacks, are discussed. We focus on MAC and routing because they are key layers in real-time communication. As most existing protocols are not suitable under realistic constraints where sensor nodes and wireless links are unreliable, we give, at the end of this chapter, some insights about future trends in designing real-time protocols. We hope to give the reader an overview of recent research works in this complex topic which we consider to be essential in critical applications.

Download Full-text

Practical Picture Processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051700 ◽

1974 ◽

Vol 32 ◽

pp. 338-339

Author(s):

T. A. Welton

Keyword(s):

Radiation Damage ◽

Coherence Length ◽

Spatial Information ◽

State Of The Art ◽

Coherent Radiation ◽

The State ◽

Energy Spread ◽

Electron Micrograph ◽

Picture Processing ◽

Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

Download Full-text