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A Unified Urban Mobile Cloud Computing
Offloading Mechanism for Smart Cities
Daniela Mazza, Daniele Tarchi, Senior Member, IEEE, and
Giovanni E. Corazza, Senior Member, IEEE,
Department of Electrical, Electronic and Information Engineering
University of Bologna
40136 Bologna, Italy
Abstract
The increasing urbanization level of the world population has driven the development of a Smart City
geographic system, conceived as a fully connected wide area characterized by the presence of a multitude
of smart devices, sensors and processing nodes aimed at distributing intelligence into the city. At the
same time, the pervasiveness of wireless technologies has led to the presence of heterogeneous networks,
operating simultaneously in the same city area. One of the main challenges in this context is to provide
sustainable solutions able to jointly optimize the data transfer, exploiting heterogeneous networks, and
the data processing, exploiting heterogeneous devices, for managing Smart City applications for the
citizens community. In this paper, the Urban Mobile Cloud Computing (UMCC) framework is developed,
introducing a mobile cloud computing model describing the flows of data and operations taking place
in the Smart City. In particular, we focus on the proposal of a unified offloading mechanism where
communication and computing resources are jointly managed allowing a load balancing among the
different entities in the environment, delegating both communication and computation tasks in order
to satisfy the Smart City application requirements. This allows to cope with the limited battery power
and computation capacity of the Smart Mobile Devices (SMDs), and plays a key role in a smart
environment where wireless communication is of utmost relevance, particularly in mobility and traffic
control domains.
Index Terms
Smart City, Mobile Cloud Computing, HetNets, Offloading mechanisms, QoS management.
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I. INTRODUCTION
According to the World Urbanization Prospect1published by the United Nations, more
than half of the population is living nowadays in urban areas, and about 70% will be city
persons by 2050. At the same time with urbanization, an extraordinary phenomenon concerning
the Information and Communication Technology (ICT) is happening: according to the Visual
Networking Index2, the number of connected devices in mobility has overtaken the number of
people in the world, and by 2018 it will be over 10 billion, including Machine to Machine
(M2M) modules in the Internet of Things. Mobile data traffic is expected to increase about 11
times in the next five years.
Urbanization and ICT expansions are finding a relevant convergence point in the Smart
City concept, the icon of sustainable and livable city, projecting the ubiquitous and pervasive
computing paradigms to urban spaces, focusing on developing city network infrastructures,
optimizing traffic and transportation flows, lowering energy consumption and offering innovative
services. It is through ICT that Smart Cities are truly turning smart [1], in particular exploiting
smart mobile devices in a Mobile Cloud Computing (MCC) context [2]. However, the huge
amount of data generated in a Smart City environment could be overwhelming, due to the rising
and diversified QoS requirements of the city services in relation to the computation time and the
energy consumed by the devices. In order to face the explosion of Big Data to be stored and
elaborated in a Smart City, mobile devices need to be supported by cloud and fog computing
structures [3], allowing an optimized load-sharing in the network for both data storage and
processing features.
For this reason, a new urban framework, named Urban MCC (UMCC), is developed herein.
While in [4]–[6] specific solutions were introduced and analyzed, here the full system view
is provided with requirements and optimization framework. UMCC can be thought of as the
technological nervous system, allowing the networks and information flows of the city to enjoy
a better urban way of life. UMCC is composed by different network and computing elements,
having heterogeneous requirements and capabilities. Within it, the offloading process emerges
as the opportune method for balancing the workload in a twofold way: on one hand, network-
offloading [7] distributes data traffic among the different wireless access technologies within the
1http://esa.un.org/unpd/wup/
2http://www.cisco.com/c/en/us/solutions/service-provider/visual-networking-index-vni/index.html
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Heterogeneous Network (HetNet) environment. On the other hand, computation-offloading, or
cyberforaging [8], delegates computing functions to the cloud. In this context, a novel unified
offloading mechanism can be envisaged. By means of the UMCC framework, data can be stored
and processed by resource-rich devices using a dynamic cell association for delegating workload,
thus shortening execution time, extending battery life and exploiting the possibility to preserve
data in the cloud. The proposed framework implements a unified offloading mechanism that
allows to optimize the system, by offloading both communication and computing tasks in order
to satisfy the Smart City application requirements.
The unified offloading operation, within the UMCC framework, can be driven by a purposely
defined utility function where throughput, energy efficiency, latency and computing performance
are taken into account. Several works have already analyzed the characteristics of MCC
offloading. In Tab. I the strengths and weaknesses with respect to UMCC of some of the most
important works are summarized.
[TABLE 1 about here.]
The rest of the paper is organized as follows. In the Section II, the main requirements of a
Smart City environment are introduced, by focusing on some specific applications. In Section III,
the proposed UMCC framework is introduced by focusing on the main constitutive entities, while
in Section IV, the offloading mechanism taking advantage of the UMCC framework is discussed.
Finally, in Section V, the conclusions are drawn.
II. REQUIREMENTS OF SMART CITY APPLICATIONS
There are many taxonomies trying to define Smart City key areas, where social aims, care
for environment, and economic issues are related and interconnected. The European Research
Cluster on the Internet of Things (IERC) has identified in [9] a list of applications in different
Internet of Things (IoT) domains, including the Smart City domain. Moreover, the Net!Works
ETP has issued a white paper [10] aiming to identify the major topics of Smart Cities that
will influence the ICT environment. Furthermore, a relevant document aiming to categorize
and define the different applications has been released by the European Telecommunications
Standards Institute (ETSI), where several application types have been specified focusing on their
bandwidth requirements [11].
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Taking into account all the relevant aforementioned essays, we selected some important Smart
City applications in order to identify their requirements and, then, to leverage the UMCC.
Each application can be defined through the services provided to the citizens, concerning the
requirements in terms of:
•Latency: the amount of time required by a certain application between the event happens
and the event is acquired by the system;
•Energy Consumption: the energy consumed for executing a certain application locally or
remotely;
•Throughput: the amount of bandwidth required by a specific application to be reliably
executed in the Smart City environment;
•Computing: the amount of computing processes requested by a certain application;
•Exchanged data: the amount of input, output and code information to be transferred by
means of the wireless network;
•Storage: the amount of storage space required for storing the sensed data and/or the
processing application;
•Users: the number of users for achieving a reliable service.
The Quality of Service (QoS) of a certain application can be seen as a function, where
each requirement plays a role less or more important depending on the application type. In
the following, we list some of the most influential Smart City applications, by highlighting their
technological requirements and characteristics, while, in Tab. II, the considered application types
and the significance of their requirements are summarized.
[TABLE 2 about here.]
a) Mobility: All the components in an intelligent transportation system could be connected
to improve transportation safety, relieve traffic congestion, reduce air pollution and enhance
comfort of driving. The necessary throughput, the computational load and the amount of data
to exchange are high, whereas we can think the storage as a secondary requirement, unless for
security recording.
b) Healthcare: Intelligent and connected medical devices, monitoring physical activity and
providing efficient therapy management by using patients’ personal devices, could be connected
to medical archives and provide information for medical diagnosis. In this case, there are
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relatively low requirements regarding energy consumption, throughput and number of users,
whereas the requirements in terms of latency, computation, exchanged data and storage are high.
c) Disaster Recovery: In a disaster relief scenario people are facing with the destruction of
the infrastructures and local citizens are asked to use their mobile phones to photograph the site.
In this case there are relatively low requirements regarding throughput, whereas it is important
to have a quick response and to save the energy of the devices.
d) Energy: Energy saving can take advantage from the cloud basically thanks to smart
grid systems, aimed to transform the behavior of individuals and communities towards a more
efficient and greener use of electric power.
e) Waste Management: Automatically generated schedules and optimized routes which take
into account an extensive set of parameters could be planned not only looking at the current
situation, but also considering the future outlook. We can expect non-restrictive requirements of
latency and throughput, whereas resource-poor devices have to be taken into consideration. The
requirements related to data to be exchanged, load of computation, storage and number of users
are not critical.
f) Tourism: Augmented reality and social networks are the characteristics of applications
that more take advantage from the cloud, that becomes also useful for mobile users sharing
photos and video clips, tagging their friends in popular social networks. We can expect
not-restrictive requirements of latency and throughput, whereas resource-poor devices have
to be taken into consideration. There are a great amount of data to be exchanged, load of
computation and storage and number of users are variable.
By comparing the above described applications, it is possible to highlight that a Smart City
scenario is composed of several heterogeneous services with different requirements. However,
it is possible to note that most of them require a high computational complexity and a very
high amount of data to be exchanged in order to be executed. Moreover, it should be noticed,
that in a Smart City scenario multiple services co-exist, increasing even more the system
requirements. This is at the base of the proposed UMCC architecture that, taking benefit from a
joint distributed computing and communication infrastructure, can be implemented through the
use of heterogeneous cloud computing and wireless networks.
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III. UMCC FRAMEWORK
UMCC sprang from the MCC, that is gaining an increasing interest in the recent years,
due to the possibility of exploiting both cloud computing and mobile devices for enabling a
distributed cloud infrastructure [2]: on one hand, the cloud computing idea has been introduced
as a mean for allowing a remote computation, storage and management of information, and,
on the other hand, the mobility skill allows to gain by the most modern smart devices and
broadband connections for creating a distributed and flexible virtual environment. At the same
time, the recent advances in the wireless technologies are defining a novel pervasive scenario
where several heterogeneous wireless networks interact among them, giving the users the ability
to select the best radio access among those in a certain area. As a consequence, the development
of UMCC is introduced, gaining from both computing and wireless communication technologies.
In the following the three pillars at the basis of the proposed UMCC framework are discussed.
A. Smart Mobile Devices (SMDs)
By analyzing the technology systems underlying a smart city framework, mobile devices can
be considered in a three-fold way:
•Sensors: They can acquire different types of data regarding the users and the environment,
transmitting a large amount of information to the cloud in real time, by means of wireless
communication systems.
•Nodes: They can form distributed mobile clouds where the neighboring mobile devices are
merged for resource sharing, becoming integral part of the network.
•Outputs: They can make the citizens aware of results and able to decide consequently, or
become actuators without need of human intervention.
To perform this triple role, mobile devices have to become part of an infrastructure that is
constituted by different cloud topologies and, at the same time, have to exploit heterogeneous
wireless link technologies, allowing to address the different requirements of a smart city scenario.
This infrastructure starts from the concept of MCC, where the cloud works as a powerful
complement to resource-constrained mobile devices.
B. Cloud Topologies
In relation to the previously described Smart Mobile Device (SMD) roles, we take into account
various cloud topologies. This is a different categorization with respect to the classical as a
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Service taxonomy used for cloud computing, i.e., Software-as-a-Service (SaaS), Platform-as-a-
Service (PaaS) and Infrastructure-as-a-Service (IaaS). It looks on the different interaction among
the nodes that form the cloud, instead of the services provided by the cloud itself, so we can
distinguish among centralized cloud, cloudlet, distributed mobile cloud and a combination of
them, as shown in Fig. 1:
•Centralized Cloud: A centralized cloud provides the citizens to interact remotely, e.g., for
accessing to open data delivered by the public administrations. It refers to the presence
of a remote cloud computing infrastructure having a huge amount of storage space and
computing power, virtually infinite, offering the major advantage of the elasticity of resource
provisioning.
•Cloudlet: Cloudlets are fixed small cloud infrastructures installed between the mobile
devices and the centralized cloud, limiting their exploitation to the users in a specific area.
Their introduction allows to decrease the latency of the access to cloud services by reducing
the transfer distance at the cost of using smaller and less powerful cloud devices.
•Distributed Mobile Cloud: A third configuration can address the issue of non persistent
connectivity, whereas both the previous concepts must assume a durable state of connection.
In a distributed mobile cloud the neighboring mobile devices are pooled together for resource
sharing [12].
The proposed UMCC framework foresees the joint exploitation of the aforementioned topologies.
[Fig. 1 about here.]
C. Heterogeneous Access Technologies
One of the most actual trend in wireless networks is the presence of a heterogeneous
access platform allowing to several types of devices with multiple network interfaces to select
among them the most suitable. Such a forthcoming scenario, introducing a higher degree of
pervasiveness, allows, especially in a Smart City scenario, to enable the access of a multitude of
different devices, from the high-end broadband user devices to the narrowband M2M devices.
Such network deployment, comprised of a mix of low-power nodes underlying the conventional
homogeneous macrocell network, by deploying additional small cells within the local-area range
and bringing the network closer to users, can significantly boost the overall network capacity
through a better spatial resource reuse. Inspired by the attractive features and potential advantages
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of HetNets, their development have gained much momentum in the wireless industry and research
communities during the past few years towards the 5G concepts.
D. Towards a unified offloading mechanism
The UMCC approach foresees the definition of a scenario where smart city applications can
exploit jointly the three cloud topologies, as shown in Fig. 2, by distributing and performing
among the different parts composing the framework, and heterogeneous wireless network access
technologies, deployed in the urban area. The application requested by a specific SMD, named
as the Requesting SMD (RSMD), is partitioned and distributed among the different clouds using
the available access networks or computed locally (Fig. 2).
[Fig. 2 about here.]
The main issue is that, for transferring data from the requesting mobile device to the
selected cloud topology, a certain time is required. This mostly depends on some communication
parameters of the selected access network, such as the end-to-end throughput, the amount of
users, the QoS management of a certain transmission technology between the user device and
each type of cloud processing unit. Moreover, the access networks themselves could be already
used by SMDs belonging to the smart city scenario, as well as other devices using the wireless
infrastructures. This involves the necessity of designing a proper offloading method that by
modeling both computing and communication resources as a single unique resource allows to
distribute the computing/communication load in a fair way among the different clouds and access
networks.
Hence, when a RSMD needs to select the cloud infrastructures to be used for computing the
smart city application, two main elements have to be taken into account:
•the processing and storage devices - smart mobiles, per se or together forming distributed
mobile clouds, and cloud servers, constituting the cloudlets and the centralized cloud;
•the wireless transmission equipment, - different access networks entailing diverse transmis-
sion speeds in relation to their own channel capacity and to the number of linked devices.
In Fig. 2, the UMCC framework is sketched by representing the functional flows of the
architecture. Whenever a smart city application has to be performed, the citizen within the
UMCC can select among different MCC infrastructures, aiming to respect the requirements of
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the specific application depending on their features. The distribution depends on the application
requirements, and the UMCC features.
Computation, storage, and transmission features: The features of the selected processing
and storage devices, considered per se or in a group forming cloud/cloudlets, are:
•Processing Speed: the speed of a device or a group of devices for processing the applications;
•Storage Capacity: the amount of storage space provided by a device or a group of devices.
At the same time, the features of the transmission equipment to be taken into account are:
•Channel Capacity: The nominal bandwidth of a certain communication technology that can
be accessed by a certain device;
•Priority/QoS management: The ability of a certain communication technology to manage
different QoS and/or priority levels;
•Communication interfaces: The number of communication interfaces of each device, that
impacts on the possibility of selecting among the available HetNets.
IV. UMCC OFFLOADING MODEL
Let’s focus on one RSMD running an application App, defined through the number of operation
to be executed, O, the amount of data to be exchanged, D, and the amount of data to be stored, S.
An application can be seen as a smart city service, that can be executed either locally or remotely
by exploiting the cloud infrastructures. Furthermore, each application has many requirements
regarding the QoS levels. Among others, the most important are:
•the maximum accepted latency TApp, intended as the interval between a task of the
application is requested and its results are acquired,
•the minimum level of energy consumption EApp, that the RSMD necessarily uses for
performing the application itself,
•the throughput ηApp, intended as the minimum bandwidth that the application needs for
being performed.
The first acting entity in the system is the RSMD, characterized by certain features that are
involved in the offloading operation: the power to compute applications locally, Pl, the power
used for transferring data towards clouds, Ptr, the power for idling during the computation in
the cloud, Pid, the computing speed to perform locally the computation, fl, and its storage
availability, Hl. Furthermore, also the time-varying position of the device plays an important
role in the system interactions.
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The different types of clouds considered in the Smart City are characterized by their computing
speed to perform the computation, i.e., fcc for the centralized cloud and fcl for cloudlets.
Additionally, while the storage availability of the centralized cloud can be considered infinite,
therefore not constraining in the interaction, the storage availability Hcl of each cloudlet has to
be taken in consideration.
The distributed cloud is a set of SMDs, each characterized by its specific features in the same
way of the RSMD, even if the role played by the SMDs is not a request but a provision of
service. Furthermore, we are considering the system from the point of view of the RSMD. Thus,
the involved features are: connectivity, computation and storage for the data exchange, i.e. the
computing speed fMD, the storage availability HMD, the position posMD(x, y), the throughput
ηMD, the number of devices that can be connected to each SMD nMD, and their coverage range
rMD.
While the connection to the cloudlets can be made only through the unique Access Point
(AP) that can be considered built-in in each cloudlet, and the connection to the SMDs of the
distributed cloud can be made directly, the nodes of the HetNet offer different alternatives to
connect towards the centralized cloud. For each involved node it is possible to define the position
of the node posNod(x, y), the end-to-end throughput in bit per second between the user and the
exploited node ηNod, the number of devices available to connect nNod, and the range of availability
of the node rNod.
Tab. III summarizes the entities and the characteristics above described. They are in a certain
relationship due to some physical and logical bounds that are derived from the following
considerations.
[TABLE 3 about here.]
In order to distribute the computing and communication loads among the different elements,
the system has to evaluate which HetNet nodes, cloudlets, and SMDs are available. On one
hand, there are Mavailable HetNet nodes Nod for the communication offloading towards the
centralized cloud, and Ncloudlets Ccl and KSMDs, able to offer computation offloading
capabilities to the RSMD. On the other hand the system has to distribute, by means of all
these entities, different percentages αiof operations O,βiof data D, and γiof memory S, to
all the available nodes, cloudlets and devices.
The requirements related to the applications, and the associated QoS, can be respected by
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optimizing the application partitioning and node/cloud association based on the features of the
processing and storage devices and of the transmission devices introduced in Section III-D;
this corresponds to design a unified offloading mechanism, that, by taking into account both
computing and communication resources and their relationships, as listed in Tab. III, as a whole,
can distribute the loads to the different devices of the environment.
In this context a utility function aiming to optimize the application dependent QoS can
be introduced, acting as input for the offloading procedure by selecting the best cloud and
communication infrastructures, as shown in Fig. 3. The model constraints are derived from the
observation that the sum of the offloaded fractions must be equal to 1, thus the optimization
problem becomes:
max
αXi,βXi {wEf(ERSMD (αXi, βXi)) + wTf(TRSMD (αXi, βXi)) + wηf(ηRSMD (αXi, βXi))}(1a)
s.t. α0+
M
X
i=1
αHNi +
N
X
i=1
αCLi +
K
X
i=1
αMDi = 1 (1b)
M
X
i=1
βHNi +
N
X
i=1
βCLi +
K
X
i=1
βMDi = 1 (1c)
The above equation corresponds to maximize a utility function defined as a weighted sum of
the functions related to the energy consumed, the time spent and the throughput achieved by
the RSMD, with constraints the amount of operations and data to be shared among the different
entities. By doing this the system performs a unified offloading mechanism by considering
jointly the communication and computing resources. In particular, the overall throughput can be
evaluated as the sum of the throughput values ηXi achievable through each node of the scenario.
The throughput ηXi is related to the number of SMDs nXi connected to the ith node and the
channel capacity BWXi of the ith node, and can be expressed by resorting to the Shannon
Formula. With respect to the latency, it can be evaluated as the sum of the local computing, the
data transfer time toward and from the cloud/cloudlets, and the idle time during the offloaded
computation. With respect to the consumed energy, it can be derived from the latency, as the
weighted sum of each latency components by the power consumed in each state.
In Fig. 3, the functional blocks of the UMCC offloading mechanism, based on a utility
function optimization, are represented. On one hand, the smart city applications define specific
requirements, while the cloud topologies in a certain scenario set their features. The utility
function aims at selecting those cloud topologies and access networks that allow to respect the
requirements by setting an optimized distribution of the application itself. The optimization of
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the partition and the node association will impact again on the UMCC features to be used by
the other applications.
[Fig. 3 about here.]
The maximization of the introduced utility function could be a nontrivial optimization problem,
depending on the considered number of applications and devices acting in the selected scenario.
To this aim different methods to find an optimal, or sub-optimal solution, of the objective function
can be employed.
a) A Greedy approach: If the offloading operation is advantageous with respect to the local
computation, the cell association scheme allows to select the ‘best’ node from the list of those
available; such list can be completed by each SMD that sort each possible access node based on
a self calculated objective function [4]. If the offloading cost is lower than the cost for the local
computation, the SMD will connect to the node which minimizes the cost function, otherwise
it will compute locally the application.
b) A cluster based approach: The idea is to divide the urban area in subareas having
range r; each SMD can share resources only with the other SMDs, cloudlets, and HetNet access
points placed in the same subarea. This approach, even if sub-optimal, can simplify the problem
by reducing the amount of concurrent devices that are involved in the offloading; in [5] a
cluster based optimization model is proposed, where the cluster size plays a significant role for
optimizing the problem while keeping low the complexity.
c) Biased Randomization: A different approach can be obtained by resorting to probabilistic
algorithms based on biased-randomization techniques [6]. In this problem setting, the most
promising node concerning the potential increase in system efficiency has to be selected. The
biased-randomization techniques work by introducing a biased or oriented random effect on the
possible solutions of a problem, allowing to choose the best solution from a set of possible
alternatives that are close to the global optimal. In [6] a biased randomization algorithm is
proposed, allowing to approach the optimal solution by gaining from a heuristic algorithm,
hence keeping the complexity low while approaching to the optimal solution. In [6], it is also
possible to note that such an approach is feasible from the implementation point of view allowing
to have a quasi-optimal solution in a reduced amount of time.
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V. CONCLUSIONS
In this paper we developed the UMCC framework, a concept that supports the smart city vision
for the optimization of the QoS of various types of smart city applications. By exploiting the
heterogeneous types of applications and devices, typical of a Smart City environment, and from
the heterogeneous computing and communication infrastructure that composes the technological
nervous system of the Smart City, the proposed UMCC framework allows to optimize the
system performance by respecting the application requirements by performing a suitable partial
offloading mechanism. The performance shown in specific applications allows to be optimistic
about the UMCC practical effectiveness.
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Daniela Mazza received the masters degrees in electronic engineering and communication science and the Ph.D. degree in
electronics, telecommunications, and information technologies engineering from the University of Bologna, Bologna, Italy.
She is an expert on system optimization in public administration organizational contexts at Emilia Romagna Local Government,
Italy. Her research interests include the services to the citizens, including solution for distributed multimedia system and services
management in a context of smart city. She possesses more than 15 years of experience in the local government organizations
and has worked as a Project Manager for technological packaging industries since 1991.
Daniele Tarchi (S’99, M’05, SM’12) received the M.Sc. degree in telecommunications engineering and the Ph.D. degree
in informatics and telecommunications engineering from the University of Florence, Florence, Italy, in 2000 and 2004,
respectively. He is currently an Assistant professor at the University of Bologna, Bologna, Italy. His research interests include the
telecommunication area, with particular interests to resource allocation and link adaptation algorithms in wireless and satellite
networks. He has been involved in several national projects as well as European projects and has been active in several industry
funded projects. Dr. Tarchi is an Editorial Board Member for the IEE Communications and for the IEEE Transactions on Vehicular
Technology, and has been an Editorial Board Member for the Wiley Wireless Communication and Mobile Computing, Hindawi
Journal of Engineering, and the Scientific World Journal and has served as an Associate Editor for the IEEE Transactions on
Wireless Communications. He was Symposium Chair at IEEE Wireless Communications and Networking Conference 2011 and
at IEEE Globecom 2014, and Workshop Co-Chair at the IEEE International Conference on Communications 2015.
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Giovanni Emanuele Corazza (M’92, SM’07) is currently a Full Professor with the Alma Mater Studiorum, University of
Bologna, Bologna, Italy, a Member of the Alma Mater Board of Directors, the Founder of the Marconi Institute for Creativity
(2011), a Member of the Marconi Society Board of Directors, a Member of the Board of the 5G Infrastructure Association, the
Vice-Chairman of the NetWorld2020 European Technology Platform, and the founder of the Mavigex S.r.l. spin-off company. He
was Head of the Department of Electronics, Computer Science and Systems (DEIS) in 20092012, the Chairman of the School
for Telecommunications in 20002003, the Chairman of the Advanced Satellite Mobile Systems Task Force (ASMS TF), the
Founder and Chairman of the Integral Satcom Initiative, a European technology platform devoted to satellite communications.
He has authored or co-authored more than 260 papers. His research interests include wireless and satellite communications,
mobile radio channel characterization, Internet of Things, navigation and positioning, estimation and synchronization, spread
spectrum and multicarrier transmission, and scientific creative thinking. Prof. Corazza served as an Editor for Communication
Theory and Spread Spectrum for the IEEE Transactions on Communications in 19972012. He was the recipient of the Marconi
International Fellowship Young Scientist Award in 1995, the IEEE 2009 Satellite Communications Distinguished Service Award,
the 2013 Newcom# Best Paper Award, the 2002 IEEE Vehicular Technology Society Best System Paper Award, the Best Paper
Award of the IEEE International Symposium on Spread Spectrum Techniques and Application (ISSSTA) 1998, at the IEEE
International Conference on Telecommunication 2001, and at the 2nd International Symposium on. Wireless Communication
Systems 2005. He was the General Chairman of the IEEE ISSSTA 2008, ASMS 20042012 Conferences, and MIC Conference
2013.
15
LIST OF FIGURES
1 Cloud topologies in the UMCC framework: centralized cloud, cloudlet and dis-
tributed mobile cloud. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2 The process of distributing and performing the application among different parts of
the UMCC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3 The utility function acts for distributing and performing the application in different
parts of the Urban MCC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
FIGURES 16
Fig. 1. Cloud topologies in the UMCC framework: centralized cloud, cloudlet and distributed mobile cloud.
FIGURES 17
Fig. 2. The process of distributing and performing the application among different parts of the UMCC.
FIGURES 18
Fig. 3. The utility function acts for distributing and performing the application in different parts of the Urban MCC.
FIGURES 19
LIST OF TABLES
I State of the Art summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
II Summary of Smart City applications and Requirements . . . . . . . . . . . . . . . 21
III Summary of entities and relations in the UMCC - Involved features and requirements 22
TABLES 20
TABLE I
STATE OF THE ART SUMMARY
Reference Objective Strengths Weaknesses w.r.t UMCC
[13] Cloud-Edge-Beneath (CEB) architecture Scalable ecosystem useful for
Smart City’s massive scale of
devices
Mostly focused on architec-
tural aspects
[14] Cloud Assisted Data Fusion Efficient selection of nodes
with respect to link quality Mostly focused on data-
collection
[15] Device To Device Based architecture Adds D2D communication to
cloud, with increased traffic
capacity
Mostly focused on the global
traffic increase
[12] Mobile as a Representer (MaaR) User-centric characterization
using proactive behaviour Mostly focused on an holistic
perspective
TABLES 21
TABLE II
SUMMARY OF SMART CITY APPLICATIONS AND REQUIREMENTS
Requirements
Application latency energy throughput computing exchanged data storage users
Mobility restrictive variable restrictive high high variable high
Healthcare restrictive non-restrictive non-restrictive high high high low
Disaster Recovery restrictive restrictive non-restrictive high high high variable
Energy non-restrictive non-restrictive non-restrictive high high high high
Waste Management non-restrictive restrictive non-restrictive low low low low
Tourism non-restrictive restrictive non-restrictive high high high variable
TABLES 22
TABLE III
SUMMARY OF ENTITIES AND RELATIONS IN THE UMCC - INVOLVED FEATURES AND REQUIREMENTS
Entity Connectivity Storage Throughput Energy Time latency
App =App(O, D, S, TApp, EApp, ηApp)-S ηApp O,D,EApp O,D,TApp
Dev =Dev(Pl, Ptr, Pid, fl, Hl, posdev(x, y)) posdev(x, y)Hl-Pl,Ptr,Pid,flfl
Ccc =Ccc(fcc)- - - fcc fcc
Ccl =Ccl(fcl, Hcl, poscl(x, y), ηcl, ncl, rcl)poscl(x, y),ncl,rcl Hcl ηcl fcl,ηcl ηcl,fcl
MD =MD(fMD, HMD,posMD(x, y), ηMD, nMD, rMD)posMD(x, y),nMD,rMD HMD ηMD fMD,ηMD ηMD,fMD
Nod =Nod(posNod(x, y), ηNod, nNod, rNod)posNod(x, y),nNod,rNod -ηNod ηNod ηNod
