-
The current methods of communications are becoming less relevant under
today’s growing demand for and reliance on constant connectivity. Of
decreasing relevance are the models of a single radio to perform a single
task. The expansion of wireless access points among coffee shops, airports,
malls, and other public arenas is opening up opportunities for new services
and applications.
標簽：
Intelligence
Artificial
上傳時間：
2020-05-26
上傳用戶：shancjb
-
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
-
Microwave radio network design is a subset of activities that constitute
the overall transmission network design. Transmission networks are
sometimes called transport networks, access networks, or connectivity
networks. For many wireless carriers, microwave is becoming a popu-
lar preference over wireline (leased lines) transport for many reasons,
especially as microwave radio equipment costs decrease and installation
becomes simpler. Low monthly operating costs can undercut those of
typical single (and especially multiple) T1/E1 expenses, proving it to be
more economical over the long term—usually two to four years. Network
operators also like the fact that they can own and control microwave
radio networks instead of relying on other service providers for network
components.
標簽：
Transmission
Microwave
Networks
上傳時間：
2020-05-28
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
-
Wireless communications is rapidly becoming one of the ubiquitous technological
underpinnings of modern society (such as electric power, fossil fuels, automobiles,
etc.).Fewpeoplethinkaboutthetechnologywithintheirmobilephones,remotecontrols,
garage door openers, GPS navigation devices, and so on. They are always at hand and
reliably work for the user.
標簽：
Practical
wireless
digital
signals
上傳時間：
2020-05-31
上傳用戶：shancjb
-
The investigation of the propagation channel is becoming more and more important in mod-
ern wireless communication. The demand for spectral efficiency motivates exploitation of
all channels that can possibly be used for communications. Nowadays, a common trend for
designing physical layer algorithms is to adapt the transceiving strategy, either by maximizing
the diversity gains or by utilizing the coherence of the channels to improve the signal-to-noise
power ratio.
標簽：
Characterization
Propagation
Channel
上傳時間：
2020-05-31
上傳用戶：shancjb
-
Quality of Service ( QoS ) has always been in a world of its own, but as the technology
has been refi ned and has evolved in recent years, QOS usage has increased to the point
where it is now considered a necessary part of network design and operation. As with
most technologies, large - scale deployments have led to the technology becoming more
mature, and QOS is no exception.
標簽：
QOS-Enabled
Networks
上傳時間：
2020-05-31
上傳用戶：shancjb
-
Recent advances in wireless communication technologies have had a transforma-
tive impact on society and have directly contributed to several economic and social
aspects of daily life. Increasingly, the untethered exchange of information between
devices is becoming a prime requirement for further progress, which is placing an
ever greater demand on wireless bandwidth. The ultra wideband (UWB) system
marks a major milestone in this progress. Since 2002, when the FCC allowed the
unlicensed use of low-power, UWB radio signals in the 3.1–10.6GHz frequency
band, there has been significant synergistic advance in this technology at the cir-
cuits, architectural and communication systems levels. This technology allows for
devices to communicate wirelessly, while coexisting with other users by ensuring
that its power density is sufficiently low so that it is perceived as noise to other
users.
標簽：
Circuits
Wideband
Ultra
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Today wireless is becoming the leader in communication choices among
users. It is not anymore a backup solution for nomadic travellers but really a
newmoodnaturallyusedeverywhereevenwhenthewiredcommunicationsare
possible. Many technologies evolve then continuously, changing the telecom-
munication world. We talk about wireless local area networks (WLANs), wire-
less personal area networks (WPANs), wireless metropolitan area networks
(WMANs), wireless wide area networks (WWANs), mobile ad hoc networks
(MANETs), wireless sensor networks (WSNs) and mesh networks. Since we
can find today a multitude of wireless technologies we decided to group a
numberofcomplementarytechnologiesintoonedocumenttomakeiteasierfor
areadertounderstandsomeofthetechnicaldetailsofeachmedia.
標簽：
TM
Bluetooth
Zigbee
Wi-Fi
WiMax
and
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Although the origins of radio frequency based wireless networking can be
traced back to the University of Hawaii’s ALOHANET research project
in the 1970s, the key events that led to wireless networking becoming
one of the fastest growing technologies of the early 21st century have
been the ratification of the IEEE 802.11 standard in 1997, and the
subsequent development of interoperability certification by the Wi-Fi
Alliance (formerly WECA).
標簽：
Networking
Technology
Wireless
上傳時間：
2020-06-01
上傳用戶：shancjb
