With the rapid expansion of wireless consumer products,there has been a con-
siderable increase in the need for radio-frequency (RF) planning, link plan-
ning, and propagation modeling.A network designer with no RF background
may find himself/herself designing a wireless network. A wide array of RF
planning software packages can provide some support, but there is no substi-
tute for a fundamental understanding of the propagation process and the lim-
itations of the models employed. Blind use of computer-aided design (CAD)
programs with no understanding of the physical fundamentals underlying the
process can be a recipe for disaster. Having witnessed the results of this
approach, I hope to spare others this frustration.
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.
Mobilenetworkoperatorswillmeetmanychallengesinthecomingyears.Itisexpectedthatthe
numberofpeopleconnected,wirelineandwireless,willreachfivebillionby2015.Atthesame
time, people use more wireless services and they expect similar user experience to what they
can now get from fixed networks. Because of that we will see a hundred-fold increase in
network traffic in the near future. At the same time markets are saturating and the revenue per
bit is dropping.
Wireless is one of the most rapidly developing technologies in our time, with dazzling
new products and services emerging on an almost daily basis. These developments present
enormous challenges for communications engineers, as the demand for increased wireless
capacity grows explosively. Indeed, the discipline of wireless communications presents
many challenges to designers that arise as a result of the demanding nature of the physical
medium and the complexities in the dynamics of the underlying network.
Mobile multimedia communication is increasingly in demand because of the basic need to communi-
cate at any time, anywhere, using any technology. In addition, to voice communication, people have a
desire to access a range of other services that comprise multimedia elements—text, image, animation,
high fidelity audio and video using mobile communication networks. To meet these demands, mobile
communication technologies has evolved from analog to digital, and the networks have passed through
a number of generations from first generation (1G) to fourth generation (4G).
Mobile radio networks have risen in prominence over the last few years, primarily by the rise
in popularity of cellular phones. It is important to recognise however that mobile radio
technology fulfils a far wider range of applications that meet the demands of the modern
world. These include the networks that allow police and emergency services to serve the
public, military networks for operations and humanitarian support, and the mobile technol-
ogies that are vital to the safety of aircraft.
Mobile telecommunications emerged as a technological marvel allowing for access to
personal and other services, devices, computation and communication, in any place and
at any time through effortless plug and play. This brilliant idea became possible as the
result of new technologies developed in the areas of computers and communications that
were made available and accessible to the user.
Wireless metropolitan area networks (WirelessMANs) is emerging as a promising
broadband wireless access (BWA) technology to provide high-speed, high bandwidth
efficiency and high-capacity multimedia services for residential as well as enterprise
applications. It is observed that WirelessMAN (e.g., WiMAX) is even regarded as a 4G
technology. For the success of the WirelessMANs, international standardization organiza-
tions are very actively specifying the standards IEEE 802.16, ETSI HiperMAN and Korea
WiBro.
Informationnetworkinghasemergedasamultidisciplinarydiversifiedareaofresearchover
thepastfewdecades.Fromtraditionalwiredtelephonytocellularvoicetelephonyandfrom
wired access to wireless access to the Internet, information networks have profoundly
impactedourlifestyle.Atthetimeofwriting,over3billionpeoplearesubscribedtocellular
services and close to a billion residences have Internet connections.
