-
An understanding of the policies, regulations, standards and techniques of radio spectrum
management is useful to those who manage and administrate it, to operators, to equipment
providers and to the users of wireless communication (i.e., all of us). For many years the author
has been deeply involved in ruling the RF spectrum at the national, regional and global levels.
The book is based on the professional experience of the author, his academic courses, presenta-
tions and tutorials in five continents. The book reflects this legacy and will be of use to engineers,
lawyers and economists, who serve the global industry of the wireless world; in it they may find
solutions to the problems they frequently encounter.
標(biāo)簽：
Management
Spectrum
Radio
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
-
Radio frequency spectrum is a scarce and critical natural resource that is utilized for
many services including surveillance, navigation, communication, and broadcast-
ing. Recent years have seen tremendous growth in the use of spectrum especially by
commercial cellular operators. Ubiquitous use of smartphones and tablets is one
of the reasons behind an all-time high utilization of spectrum. As a result, cellular
operators are experiencing a shortage of radio spectrum to meet bandwidth
demands of users. On the other hand, spectrum measurements have shown that
much spectrum not held by cellular operators is underutilized even in dense urban
areas. This has motivated shared access to spectrum by secondary systems with no
or minimal impact on incumbent systems. Spectrum sharing is a promising
approach to solve the problem of spectrum congestion as it allows cellular operators
access to more spectrum in order to satisfy the ever-growing bandwidth demands of
commercial users.
標(biāo)簽：
Spectrum
Sharing
Between
Radars
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
-
When 3GPP started standardizing the IMS a few years ago, most analysts expected the
number of IMS deploymentsto grow dramatically as soon the initial IMS specifications were
ready (3GPP Release 5 was functionallyfrozenin the first half of 2002and completedshortly
after that). While those predictions have proven to be too aggressive owing to a number of
upheavals hitting the ICT (Information and Communications Technologies) sector, we are
now seeing more and more commercial IMS-based service offerings in the market. At the
time of writing (May 2008), there are over 30 commercial IMS networks running live traffic,
addingup to over10million IMS users aroundthe world; the IMS is beingdeployedglobally.
In addition, there are plenty of ongoing market activities; it is estimated that over 130 IMS
contracts have been awarded to all IMS manufacturers. The number of IMS users will grow
substantially as these awarded contracts are launched commercially. At the same time, the
number of IMS users in presently deployed networks is steadily increasing as new services
are introduced and operators running these networks migrate their non-IMS users to their
IMS networks.
標(biāo)簽：
Multimedia
Subsystem
The
IMS
3G
IP
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
-
Public telephone operators and new independent wireless operators through-
out the world are deploying wireless access in an effort to drastically reduce
delivery costs in the most expensive part of the network?the local loop.
Available radio technology enables both existing and new entrants to access
subscribers in a rapid manner and deliver their basic telephony products and
broadband-enhanced services.
標(biāo)簽：
Transmission
Handbooks
Systems
Design
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
-
Telecommunications is today widely understood to mean the electrical means of
communicating over a distance. The first form of telecommunications was that of
the Telegraph, which was invented quite independently in 1837 by two scientists,
Wheatstone and Morse. Telegraphy was on a point-to-point unidirectional basis and
relied on trained operators to interpret between the spoken or written word and the
special signals sent over the telegraph wire. However, the use of telegraphy did
greatly enhance the operations of railways and, of course, the dissemination of news
and personal messages between towns.
標(biāo)簽：
Telecommunications
Understanding
Networks
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
-
Once upon a time, cellular wireless networks provided two basic services: voice
telephony and low-rate text messaging. Users in the network were separated
by orthogonal multiple access schemes, and cells by generous frequency reuse
patterns [1]. Since then, the proliferation of wireless services, fierce competition,
andthe emergenceof new service classes such as wireless data and multimediahave
resulted in an ever increasing pressure on network operators to use resources in a
moreefficient manner.In the contextof wireless networks,two of the most common
resources are power and spectrum—and, due to regulations, these resources are
typically scarce. Hence, in contrast to wired networks, overprovisioning is not
feasible in wireless networks.
標(biāo)簽：
Maximization
Nonconvex
Wireless
Utility
Systems
in
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
-
With the proliferation of cloud computing and Internet online services, more and
more data and computation are migrated to geographical distributed Internet data
centers (IDCs), which can provide reliability, management, and cost benefits.
However, IDC operators encounter several major problems in IDC operations, such
as huge energy consumption and energy cost, and high carbon emission. To deal
with the above problems, IDC operators have to efficiently manage the way of
energy consumption and energy supply. Considering the potential of smart grid, we
focus on the energy management of IDCs in smart grid from several perspectives,
i.e., power outage, carbon emission, heterogeneous service delay guarantees, and
operation risk.
標(biāo)簽：
Internet
Centers
Data
上傳時(shí)間：
2020-06-07
上傳用戶：shancjb
-
The term “ smart grid ” defi nes a self - healing network equipped with dynamic optimiza-
tion techniques that use real - time measurements to minimize network losses, maintain
voltage levels, increase reliability, and improve asset management. The operational data
collected by the smart grid and its sub - systems will allow system operators to rapidly
identify the best strategy to secure against attacks, vulnerability, and so on, caused by
various contingencies. However, the smart grid fi rst depends upon identifying and
researching key performance measures, designing and testing appropriate tools, and
developing the proper education curriculum to equip current and future personnel with
the knowledge and skills for deployment of this highly advanced system.
標(biāo)簽：
Smart
Grid
上傳時(shí)間：
2020-06-07
上傳用戶：shancjb
