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Wireless Fidelity (Wi-Fi) networks have become mainstream over the last few years. What
started out as cable replacement for static desktops in indoor networks has been extended
to fully mobile broadband applications involving moving vehicles, high-speed trains, and
even airplanes.
標(biāo)簽：
Technologies
Emerging
Wireless
Theory
LANs
in
上傳時(shí)間：
2020-05-27
上傳用戶(hù)：shancjb
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The next-generation wireless broadband technology is changing the way
we work, live, learn, and communicate through effective use of state-
of-the-art mobile broadband technology. The packet-data-based revolu-
tion started around 2000 with the introduction of 1x Evolved Data Only
(1xEV-DO) and 1x Evolved Data Voice (1xEV-DV) in 3GPP2 and High
Speed Downlink Packet Access (HSDPA) in 3GPP. The wireless broad-
band fourth-generation technology (4G) is an evolution of the packet-
based 3G system and provides a comprehensive evolution of the
Universal Mobile Telecommunications System specifications so as to
remain competitive with other broadband systems such as 802.16e
(WiMAX)
標(biāo)簽：
Essentials
LTE-A
LTE
and
of
上傳時(shí)間：
2020-05-27
上傳用戶(hù)：shancjb
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With the rapid growth in the number of wireless applications, services and devices,
using a single wireless technology such as a second generation (2G) and third gener-
ation (3G) wireless system would not be efficient to deliver high speed data rate and
quality-of-service (QoS) support to mobile users in a seamless way. The next genera-
tion wireless systems (also sometimes referred to as Fourth generation (4G) systems)
are being devised with the vision of heterogeneity in which a mobile user/device will
be able to connect to multiple wireless networks (e.g., WLAN, cellular, WMAN)
simultaneously.
標(biāo)簽：
Heterogeneous
Wireless
Networks
Access
上傳時(shí)間：
2020-05-27
上傳用戶(hù)：shancjb
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The first Third Generation Partnership Project (3GPP) Wideband Code Division
Multiple Access (WCDMA) networks were launched during 2002. By the end of 2005
there were 100 open WCDMA networks and a total of over 150 operators having
frequency licenses for WCDMA operation. Currently, the WCDMA networks are
deployedinUniversalMobileTelecommunicationsSystem(UMTS)bandaround2GHz
in Europe and Asia including Japan and Korea. WCDMA in America is deployed in the
existing 850 and 1900 spectrum allocations while the new 3G band at 1700/2100 is
expected to be available in the near future. 3GPP has defined the WCDMA operation
also for several additional bands, which are expected to be taken into use during the
coming years.
標(biāo)簽：
HSDPAHSUPA
Access
Speed
Radio
UMTS
High
for
上傳時(shí)間：
2020-05-27
上傳用戶(hù)：shancjb
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In the nineteenth century, scientists, mathematician, engineers and innovators started
investigating electromagnetism. The theory that underpins wireless communications was
formed by Maxwell. Early demonstrations took place by Hertz, Tesla and others. Marconi
demonstrated the first wireless transmission. Since then, the range of applications has
expanded at an immense rate, together with the underpinning technology. The rate of
development has been incredible and today the level of technical and commercial maturity
is very high. This success would not have been possible without understanding radio-
wave propagation. This knowledge enables us to design successful systems and networks,
together with waveforms, antennal and transceiver architectures. The radio channel is the
cornerstone to the operation of any wireless system.
標(biāo)簽：
LTE-Advanced
Generation
Next
and
上傳時(shí)間：
2020-05-27
上傳用戶(hù)：shancjb
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With the rapid growth of the wireless mobile applications, wireless voice has
begun to challenge wireline voice, whereas the desire to access e-mail, surf the
Web or download music (e.g., MP3) wirelessly is increasing for wireless data.
While second generation (2G) cellular wireless systems, such as cdmaOne1,
GSM2 and TDMA3, introduced digital technology to wireless cellular systems
to deal with the increasing demand for wireless applications, there is still the
need for more spectrally efficient technologies for two reasons. First, wireless
voice capacity is expected to continue to grow. Second, the introduction of
high-speed wireless data will require more bandwidth.
標(biāo)簽：
Wireless
Systems
Mobile
Beyond
and
3G
上傳時(shí)間：
2020-05-30
上傳用戶(hù)：shancjb
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Emerging technologies such as WiFi and WiMAX are profoundly changing the
landscape of wireless broadband. As we evolve into future generation wireless
networks, a primary challenge is the support of high data rate, integrated multi-
media type traffic over a unified platform. Due to its inherent advantages in
high-speed communication, orthogonal frequency division multiplexing (OFDM)
has become the modem of choice for a number of high profile wireless systems
(e.g., DVB-T, WiFi, WiMAX, Ultra-wideband).
標(biāo)簽：
OFDM-Based
Broadband
Networks
Wireless
上傳時(shí)間：
2020-05-31
上傳用戶(hù)：shancjb
-
Rapid progress in information and communications technology (ICT) induces
improved and new telecommunications services and contributes greatly to society
in general and to vendors and network and service providers. In addition to existing
services such as telephony or leased line services, spread of the Internet, the Internet
Protocol (IP) phone, and new communications services like IPTV are making great
progress with the development of digital subscriber lines (DSL) and high - speed
communications technologies like fi ber to the home (FTTH).
標(biāo)簽：
Telecommunications
Networks
上傳時(shí)間：
2020-06-01
上傳用戶(hù)：shancjb
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Changes in telecommunications are impacting all types of user
group, which include business users, traveling users, small and
home offices, and residential users. The acceptance rate of telecom-
munications and information services is accelerating significantly.
Voice services needed approximately 50 years to reach a very high
teledensity; television needed just 15 years to change the culture
and lives of many families; the Internet and its related services have
been penetrating and changing business practices and private com-
munications over the last 2 to 3 years.
標(biāo)簽：
Telecommunications
Handbook
The
上傳時(shí)間：
2020-06-01
上傳用戶(hù)：shancjb
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The advent of modern wireless devices, such as smart phones and MID 1 terminals,
has revolutionized the way people think of personal connectivity. Such devices
encompass multiple applications ranging from voice and video to high-speed data
transfer via wireless networks. The voracious appetite of twenty-first century users
for supporting more wireless applications on a single device is ever increasing.
These devices employ multiple radios and modems that cover multiple frequency
bands and multiple standards with a manifold of wireless applications often running
simultaneously.
標(biāo)簽：
Architectures
Wireless
Receiver
Design
and
上傳時(shí)間：
2020-06-01
上傳用戶(hù)：shancjb
