-
For nearly a hundred years telecommunications provided mainly voice services and very low speed
data (telegraph and telex). With the advent of the Internet, several data services became mainstream
in telecommunications; to the point that voice is becoming an accessory to IP-centric data networks.
Today, high-speed data services are already part of our daily lives at work and at home (web surfing,
e-mail, virtual private networks, VoIP, virtual meetings, chats...). The demand for high-speed data
services will grow even more with the increasing number of people telecommuting.
標簽：
WiMAX
WLAN
LTE
and
上傳時間：
2020-05-27
上傳用戶：shancjb
-
The ever-increasing demand for private and sensitive data transmission over wireless net-
works has made security a crucial concern in the current and future large-scale, dynamic,
and heterogeneous wireless communication systems. To address this challenge, computer
scientists and engineers have tried hard to continuously come up with improved crypto-
graphic algorithms. But typically we do not need to wait too long to find an efficient way
to crack these algorithms. With the rapid progress of computational devices, the current
cryptographic methods are already becoming more unreliable. In recent years, wireless re-
searchers have sought a new security paradigm termed physical layer security. Unlike the
traditional cryptographic approach which ignores the effect of the wireless medium, physi-
cal layer security exploits the important characteristics of wireless channel, such as fading,
interference, and noise, for improving the communication security against eavesdropping
attacks. This new security paradigm is expected to complement and significantly increase
the overall communication security of future wireless networks.
標簽：
Communications
Physical
Security
Wireless
Layer
in
上傳時間：
2020-05-31
上傳用戶：shancjb
-
We are currently witnessing an increase in telecommunications norms and
standards given the recent advances in this domain. The increasing number of
normalized standards paves the way for an increase in the range of offers and
services available for each consumer. Moreover, the majority of available radio
frequencies have already been allocated.
標簽：
Allocation
Resource
Radio
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Driven by the desire to boost the quality of service of wireless systems closer to that afforded
by wireline systems, space-time processing for multiple-input multiple-output (MIMO)
wireless communications research has drawn remarkable interest in recent years. Excit-
ing theoretical advances, complemented by rapid transition of research results to industry
products and services, have created a vibrant and growing area that is already established
by all counts. This offers a good opportunity to reflect on key developments in the area
during the past decade and also outline emerging trends.
標簽：
Space-Time
Processing
上傳時間：
2020-06-01
上傳用戶：shancjb
-
The continuing explosive growth in mobile communication is demanding more spectrally
efficient radio access technologies than the prevalent second generation (2G) systems such as
GSM to handle just the voice traffic. We are already witnessing high levels of mobile
penetration exceeding 70% in some countries. It is anticipated that by 2010 more than half of
all communications will be carried out by mobile cellular networks. On the other hand, the
information revolution and changing life habits are bringing the requirement of commu-
nicating on a multimedia level to the mobile environment. But the data handling capabilities
and flexibility of the 2G cellular systems are limited.
標簽：
Planning
Network
UMTS
上傳時間：
2020-06-01
上傳用戶：shancjb
-
This chapter provides extensive coverage of existing mobile wireless technologies. Much of the
emphasis is on the highly anticipated 3G cellular networks and widely deployed wireless local
area networks (LANs), as the next-generation smart phones are likely to offer at least these two
types of connectivity. Other wireless technologies that either have already been commercialized or
are undergoing active research and standardization are introduced as well. Because standardization
plays a crucial role in developing a new technology and a market, throughout the discussion
standards organizations and industry forums or consortiums of some technologies are introduced.
In addition, the last section of this chapter presents a list of standards in the wireless arena.
標簽：
Networking
Wireless
Complete
上傳時間：
2020-06-01
上傳用戶：shancjb
-
GaN is an already well implanted semiconductor
technology, widely diffused in the LED optoelectronics
industry. For about 10 years, GaN devices have also been
developed for RF wireless applications where they can
replace Silicon transistors in some selected systems. That
incursion in the RF field has open the door to the power
switching capability in the lower frequency range and
thus to the power electronic applications.
Compared to Silicon, GaN exhibits largely better figures
for most of the key specifications: Electric field, energy
gap, electron mobility and melting point. Intrinsically,
GaN could offer better performance than Silicon in
terms of: breakdown voltage, switching frequency and
Overall systems efficiency.
標簽：
GaN-on-Si
Displace
and
SiC
Si
上傳時間：
2020-06-07
上傳用戶：shancjb
-
If one examines the current literature on GPS receiver design, most of it is quite a
bit above the level of the novice. It is taken for granted that the reader is already at a
fairly high level of understanding and proceeds from there. This text will be an
attempt to take the reader through the concepts and circuits needed to be able to
understand how a GPS receiver works from the antenna to the solution of user
position.
標簽：
Fundamentals_of_Global_Positionin
g_System
上傳時間：
2020-06-09
上傳用戶：shancjb
-
This book describes a unifying framework to networked teleoperation systems
cutting across multiple research fields including networked control system for linear
and nonlinear forms, bilateral teleoperation, trilateral teleoperation, multilateral
teleoperation, cooperative teleoperation, and some teleoperation application
examples. Networked control has been deeply studied at the intersection of systems
& control and robotics for a long time, and many scholarly books on the topic have
been already published. Nevertheless, the approach remains active even in several
new research fields, such as bilateral teleoperation, single master and multiple
slaves, trilateral teleoperation, and multilateral teleoperation
標簽：
Teleoperation
Intelligent
Networked
Control
上傳時間：
2020-06-10
上傳用戶：shancjb
-
Modern information technologies and the advent of machines powered by artificial
intelligence (AI) have already strongly influenced the world of work in the 21st century.
Computers, algorithms and software simplify everyday tasks, and it is impossible
to imagine how most of our life could be managed without them. However, is it
also impossible to imagine how most process steps could be managed without
human force? The information economy characterised by exponential growth
replaces the mass production industry based on economy of scales
標簽：
AI-and-Robotics-IBA-GEI-April
2017
上傳時間：
2020-06-10
上傳用戶：shancjb
