In recent years, cellular voice networks have transformed into powerful packet-switched
access networks for both voice communication and Internet access. Evolving Universal
Mobile Telecommunication System (UMTS) networks and first Long Term Evolution
(LTE) installations now deliver bandwidths of several megabits per second to individual
users, and mobile access to the Internet from handheld devices and notebooks is no
longer perceived as slower than a Digital Subscriber Line (DSL) or cable connection.
Bandwidth and capacity demands, however, keep rising because of the increasing number
of people using the networks and because of bandwidth-intensive applications such as
video streaming. Thus, network manufacturers and network operators need to find ways
to continuously increase the capacity and performance of their cellular networks while
reducing the cost.
The surge of mobile data traffic forces network
operators to cope with capacity shortage. The deployment of
small cells in 5G networks is meant to reduce latency, backhaul
traffic and increase radio access capacity. In this context, mobile
edge computing technology will be used to manage dedicated
cache space in the radio access network. Thus, mobile network
operators will be able to provision OTT content providers with
new caching services to enhance the quality of experience of their
customers on the move.
A decade ago, I first wrote that people moved, and networks needed to adapt to the
reality that people worked on the go. Of course, in those days, wireless LANs came
with a trade-off. Yes, you could use them while moving, but you had to trade a great
deal of throughput to get the mobility. Although it was possible to get bits anywhere,
even while in motion, those bits came slower. As one of the network engineers I worked
with put it, “We’ve installed switched gigabit Ethernet everywhere on campus, so I
don’t understand why you’d want to go back to what is a 25-megabit hub.” He un-
derestimated the allure of working on the go.
Device-to-device(D2D) communications are now considered as an integral part of future 5G networks
which will enable direct communication between user equipment (UE) without unnecessary routing via
the network infrastructure. This architecture will result in higher throughputs than conventional cellular
networks, but with the increased potential for co-channel interference induced by randomly located
cellular and D2D UEs.
The past two decades have witnessed the introduction and unprecedented growth of cellular
mobile telephony and wireless communications. Numerous wireless access technologies
have been introduced in the mobile communications market. While some have flourished
and formed the basis of successful manufacturing and network operator businesses, many
have lived only for a short time and disappeared.
The telecommunications industry has seen a rapid boost within the last decade. New realities
and visions of functionalities in various telecommunications networks have brought forward the
concept of next-generation networks (NGNs). The competitions among operators for support-
ing various services, lowering of the cost of having mobile and cellular phones and smartphones,
increasing demand for general mobility, explosion of digital traffic, and advent of convergence
network technologies added more dynamism in the idea of NGNs. In fact, facilitating con-
vergence of networks and convergence of various types of services is a significant objective of
NGN
The idea of writing this book entitled “Cognitive Networked Sensing and Big Data”
started with the plan to write a briefing book on wireless distributed computing
and cognitive sensing. During our research on large-scale cognitive radio network
(and its experimental testbed), we realized that big data played a central role. As a
result, the book project reflects this paradigm shift. In the context, sensing roughly
is equivalent to “measurement.”
Today’s wireless services have come a long way since the roll out of the
conventional voice-centric cellular systems. The demand for wireless access
in voice and high rate data multi-media applications has been increasing.
New generation wireless communication systems are aimed at accommodating
this demand through better resource management and improved transmission
technologies.
This thesis is about wireless communication in shared radio spectrum. Its origin and
motivation is ideally represented by the two quotations from above. In this thesis, the
support of Quality-of-Service (QoS) in cognitive radio networks is analyzed. New
approaches to distributed coordination of cognitive radios are developed in different
spectrum sharing scenarios. The Wireless Local Area Network (WLAN) 802.11 proto-
col of the Institute of Electrical and Electronics Engineers (IEEE) (IEEE, 2003) with
its enhancement for QoS support (IEEE, 2005d) is taken as basis. The Medium Access
Control (MAC) of 801.11(e) is modified to realize flexible and dynamic spectrum
assignment within a liberalized regulation framework.
The General Packet Radio Service (GPRS) allows an end user to send and
receive data in packet transfer mode within a public land mobile network
(PLMN) without using a permanent connection between the mobile station
(MS) and the external network during data transfer. This way, GPRS opti-
mizes the use of network and radio resources (RRs) since, unlike circuit-
switched mode, no connection between the MS and the external network is
established when there is no data flow in progress. Thus, this RR optimiza-
tion makes it possible for the operator to offer more attractive fees.