The AP2406 is a 1.5Mhz constant frequency, slope compensated current mode PWM step-down converter. The device integrates a main switch and a synchronous rectifier for high efficiency without an external Schottky diode. It is ideal for powering portable equipment that runs from a single cell lithium-Ion (Li+) battery. The AP2406 can supply 600mA of load current from a 2.5V to 5.5V input voltage. The output voltage can be regulated as low as 0.6V. The AP2406 can also run at 100% duty cycle for low dropout operation, extending battery life in portable system. Idle mode operation at light loads provides very low output ripple voltage for noise sensitive applications.
The AP2406 is offered in a low profile (1mm) 5-pin, thin SOT package, and is available in an adjustable version and fixed output voltage of 1.2V, 1.5V and 1.8V
I saw the light of the future when I first read Ray Kurzweil’s best-seller book The
Singularity Is Near: When Humans Transcend Biology. One cubic inch of nanotube cir-
cuitry, once fully developed, would be up to one hundred million times more powerful
than the human brain.
Your Cisco Networking Academy Course Booklet is designed as a study resource you can easily read, high-
light, and review on the go, wherever the Internet is not available or practical:
■ The text is extracted directly, word-for-word, from the online course so you can highlight important
points and take notes in the “Your Chapter Notes” section.
■ Headings with the exact page correlations provide a quick reference to the online course for your class-
room discussions and exam preparation.
■ An icon system directs you to the online curriculum to take full advantage of the images, labs, Packet
Tracer activities, and dynamic Flash-based activities embedded within the Networking Academy online
course interface.
An optical fiber amplifier is a key component for enabling efficient transmission of
wavelength-divisionmultiplexed(WDM)signalsoverlongdistances.Eventhough
many alternative technologies were available, erbium-doped fiber amplifiers won
theraceduringtheearly1990sandbecameastandardcomponentforlong-haulopti-
caltelecommunicationssystems.However,owingtotherecentsuccessinproducing
low-cost, high-power, semiconductor lasers operating near 1450 nm, the Raman
amplifiertechnologyhasalsogainedprominenceinthedeploymentofmodernlight-
wavesystems.Moreover,becauseofthepushforintegratedoptoelectroniccircuits,
semiconductor optical amplifiers, rare-earth-doped planar waveguide amplifiers,
and silicon optical amplifiers are also gaining much interest these days.
One of the prerequisites for the development of telecommunication services is the
understanding of the propagation of the waves, either acoustic, electromagnetic,
radio or light waves, which are used for the transmission of information.
In this work, we shall limit ourselves to the study of radio waves: this term
apply to the electromagnetic waves used in radio communications. Their
frequency spectrum is very broad, and is divided into the following frequency
bands : ELF waves (f < 3 kHz), VLF (3-30 kHz), LF waves (30-300 kHz), MF
waves (300-3000 kHz), HF (3-30 MHz), VHF waves (30-300 MHz), UHF waves
(300-3000 MHz), SHF waves (3-30 GHz), EHF waves (30-300 GHz) and sub-
EHF waves (300-3000 GHz).
Before I can present design concepts or tactical wireless communications and network
challenges, I feel the need to mention the challenges of writing for a field where some
information is not available for public domain and cannot be included in this book’s context.
Another challenge is the use of military jargon and the extensive number of abbreviations
(and abbreviations of abbreviations!) in the field. Engineering books are naturally dry, and I
have attempted to make it light by presenting the concepts in layman’s terms before diving
into the technical details. I am structuring this book in such a way as to make it useful for
a specialized graduate course in tactical communications and networking, or as a reference
book in the field.
Long-TermEvolution(LTE)isarguablyoneofthemostimportantstepsinthecurrentphaseof
the development of modern mobile communications. It provides a suitable base for enhanced
services due to increased data throughput and lower latency figures, and also gives extra
impetus to the modernization of telecom architectures. The decision to leave the circuit-
switched domainoutofthescope ofLTE/SAEsystem standardization might soundradical but
itindicatesthatthetelecomworldisgoingstronglyfortheall-IPconcept----andthedeployment
of LTE/SAE is concrete evidence of this global trend.
The use of light to send messages is not new. Fires were used for signaling in
biblical times, smoke signals have been used for thousands of years and flashing
lights have been used to communicate between warships at sea since the days of
Lord Nelson.
The idea of using glass fibre to carry an optical communications signal originated
with Alexander Graham Bell. However this idea had to wait some 80 years for
better glasses and low-cost electronics for it to become useful in practical
situations.
