|
Globecom
2013 Workshop - Management of Emerging
Networks and Services Program
Monday, December 9, 2013
Time |
Room: 302 |
Room:
303 |
09:00-10:00 |
Keynotes 1: hot topics in
research and the links to
standardization |
10:00-10:30 |
Coffee break |
10:30-11:30 |
MENS 1-1: SDN & Openflow,
and Network Virtualization |
MENS
2-1: Energy efficiency for emerging
networks |
11:30-12:30 |
MENS 1-2: SDN & Openflow,
and Network Virtualization |
MENS
2-2: Energy efficiency for emerging
networks |
12:30-13:30 |
Lunch break |
13:30-14:45 |
Keynotes 2: Q&A Panel
with Industry: IPv6, SDN & NFV,
Autonomic & Converged Management |
14:45-15:30 |
MENS:3: LTE Technology and
Management & Control |
MENS:4:
QoS and performance optimization |
15:30-16:00 |
Coffee break |
16:00-17:00 |
MENS 5: Management of
Emerging Networks |
MENS 6: Autonomic networking,
cognitive networking and
self-Management |
Monday,
December 9
09:00 - 10:00
Keynotes
1: hot topics in research and the links to
standardization
- SDN Enablers
in the ETSI AFI GANA Reference Model for
Autonomic Management & Control
(emerging standard), and Virtualization
Impact
-
Ranganai Chaparadza
(IPv6 Forum, Germany); Tayeb Ben Meriem
(Orange, France); Benoit Radier (Orange
France Telecom R&D, France); Szymon
Szott (AGH University of Science and
Technology, Poland); Michal Wodczak
(Department of Information Technology at
Poznan University of Economics, Poland);
Arun Prakash (Fraunhofer FOKUS &
Technische Universität Berlin, Germany);
Jianguo Ding (University of Skövde,
Sweden); Said Soulhi (Ericsson, Sweden);
Andrej Mihailovic (King's College London,
United Kingdom)
This paper is standardization
oriented paper that describes the SDN
(Software-Driven Networking) Enablers in
the ETSI AFI GANA Reference Model for
Autonomic Management & Control (an
emerging standard from ETSI), and impact
of Virtualization. This is because in this
study we see that Autonomic Management
& Control and SDN (Software-Driven
Networking) share the same objective of
enabling programmable, manageable,
dynamically self-adaptable and
cost-effective networks and services. (1)
Modularization of Logically centralized
Control Software (GANA Network Level DEs
in the GANA Knowledge Plane) and Reference
Points Definitions; (2) Primitives for
Programmability at various layers; (3)
Run-time Executable Behavioral Models to
complement Policy-Control with dynamic
policies; (4) The role and value the GANA
MBTS (Model Based Translation Service)
brings in SDN; (5) The role and value the
GANA ONIX (Overlay Network for Information
eXchange) brings in SDN; (6) Interworking
GANA Knowledge Plane Decision Elements and
OpenFlow-based Controllers. The study is
important because it is now becoming
critical to study and explore the
relationships between Autonomic Management
& Control and SDN enabling frameworks,
as well as Virtualization, identify
complementarities between the paradigms
and close the gaps by unifying SDN
concepts and associated frameworks with
the emerging ETSI AFI GANA Reference Model
standard for Autonomic Networking,
Cognitive Networking and Self-Management.
10:30 - 11:30
MENS 1-1:
SDN & Openflow, and Network Virtualization
- Mobile Core
Traffic Balancing by OpenFlow Switching
System
-
Ebrahim Ghazisaeedi
(Carleton University, Canada); Rahim
Tafazolli (University of Surrey, United
Kingdom)
Nowadays, one of the main
problems of mobile operators is to handle
network traffic more resourcefully.
Techniques, which increase the traffic
capacity over the mobile core with minimum
costs, play a fundamental role. Following
advent of smart phones, the most of the
traffic bandwidth is being used for
connecting to external IP networks, like
the Internet. Consequently, this
overloaded traffic causes congestion over
the mobile core network and degrade the
quality of service. In this regard, we
suggest a process using recently revealed
switching system (OpenFlow), to balance
the traffic over the mobile core network
and use resources more efficiently. In
this paper, we imply a technique to
decrease the core network load using this
switching system and provide a better
quality of service for specific services
over 3G and Evolved Packet Core (EPC).
Mobile Operators with the proposed
solution may save millions of dollars per
year.
- An Autonomic
Management Architecture for SDN-based
Multi-service Network
-
Hongyun Li (Beijing
University of Posts and
Telecommunications, P.R. China); Xirong
Que (Institute of Networking Technology,
P.R. China); Yannan Hu (Beijing University
of Posts and Telecommunications, P.R.
China); Gong Xiangyang (Beijing University
of Posts and Telecommunications P.R.
China, P.R. China); Wang Wendong (Beijing
University of Posts and
Telecommunications, P.R. China)
Software-Defined Networking
(SDN) is a new paradigm, which emerged in
the innovation for future networks and has
been successfully applied in many
scenarios including Campus/Enterprise
network and Data Center network. By
extending the concept of SDN and
autonomicity to the design of versatile
network infrastructures, especially to the
design of a carrier grade network, we
propose AMA, which is an autonomic
management architecture for SDN-based
multi-service network. AMA is designed and
implemented by utilizing autonomic
management and network virtualization
technologies. We believe that AMA can
support more application types, and can be
used to build a more flexible network.
- CIM-SDN: A
Common Information Model extension for
Software-Defined Networking
-
Billy Pinheiro (Federal
University of Para - UFPA, Brazil); Rafael
Chaves (Federal University of Para - UFPA,
Brazil); Eduardo Cerqueira (Federal
University of Para & UFPA, Brazil);
Antonio Jorge Gomes Abelem (UFPA - Federal
University of Pará, Brazil)
The increase in complexity of
computer networks and their services have
boosted the development of
standardizations, models and solutions for
network management over the years. Lately,
the Distributed Management Task Force
(DMTF) defined the Common Information
Model (CIM) for describing computational
entities and businesses on the Internet.
This paper proposes an extension of the
CIM for Software-Defined Networking (SDN)
by adding new elements (Controllers, Apps,
Slices and others). Furthermore, we define
a metamodel to help the process of
creating and understanding the proposed
model. The proposal was validated by
creating a script that generates the
FlowVisor configuration file using the
network model as input and using Object
Constraint Language (OCL) to find
inconsistencies in the network.
- PindSwitch: A
SDN-based Protocol-independent Autonomic
Flow Processing Platform
-
Tong Zhou (Beijing
University of Posts and
Telecommunications, P.R. China); Gong
Xiangyang (Beijing University of Posts and
Telecommunications P.R. China, P.R.
China); Yannan Hu (Beijing University of
Posts and Telecommunications, P.R. China);
Xirong Que (Institute of Networking
Technology, P.R. China); Wang Wendong
(Beijing University of Posts and
Telecommunications, P.R. China)
Software Defined Networking
(SDN) has already gained enormous momentum
in the industry. Its innovation
architecture that separates the control
and forwarding planes allow third-party
developers more leeway in how a network
behaves. Since new protocols and
forwarding schemes are needed to produce
better network performance, efforts have
been put forth in redefining user-defined
protocol support. Besides, the concept of
autonomicity has been proposed recently to
solve the dilemma of management in complex
network environments. In this paper, we
propose the design and implementation of
PindSwitch, which provides a SDN-based
Protocol-independent platform to allow
users to outline their own protocols'
format and flow processing rules into
physical switches. We also introduce
autonomicity and self-* attributes into
SDN by extending the architecture of GANA
to achieve better management of
user-defined protocols and their
processing schemes.
- EDGS:
Efficient Data Gathering Scheme for Dense
Wireless Sensor Networks
-
Saad Al-Ahmadi (College
of Computer and Information Sciences, King
Saud University, Saudi Arabia); Abdullah
Al-Dhelaan (King Saud University, Saudi
Arabia)
Dense and large scale Wireless
Sensor Networks (WSNs) require efficient
data gathering strategies that are robust,
scalable, cover large areas, and extend
network lifetime. We propose EDGS as novel
and efficient data gathering algorithm to
collect data from these challenging WSNs.
EDGS creates virtual network backbone
based on the Gray Cube regular graph
structure. EDGS collects data in parallel
short paths, balances energy consumption,
and is highly tolerant against sensor
failures. The backbone construction is
adaptive with good connectivity, low
network diameter, and short average path
length. We present several versions of
EDGS for constructing the backbone using
top-down or bottom-up techniques and
centralized or distributed approaches. The
backbone sensors act as access points for
non backbone sensors for local data
collection. We conduct comparative study
using modeling techniques and NS-2
simulation to demonstrate EDGS's
efficiency and its superiority compared to
other recently proposed data gathering
techniques in terms of energy consumption,
gathering delay, scalability, QoS
requirements, and fault tolerance.
MENS 2-1:
Energy efficiency for emerging networks
- Optimized
Scheduling of Power in an Islanded
Microgrid with Renewables and Stored
Energy
-
Arif Isikman (TOBB
University of Economics and Technology,
Turkey); Seçkin Anıl Yıldırım (TOBB
University of Economics and Technology,
Turkey); Cankal Altun (TOBB University of
Economics and Technology, Turkey);
Suleyman Uludag (The University of
Michigan - Flint, USA); Bulent Tavli (TOBB
University of Economics and Technology,
Turkey)
The conception of the Smart Grid
(SG) paradigm is to offer many benefits to
the transmission, distribution, and
consumption of energy. One catalyzer
ingredient of the SG repertoire of changes
is the idea of microgrids. As a new low
voltage distribution subsystem, microgrids
are expected to improve reliability, help
integrate distributed resources, isolate
power disturbances, and ameliorate load
and supply balance. In this paper, we
study a microgrid power scheduling problem
with renewable sources and energy storage
where five different classes of appliances
are prioritized by smart meters. A novel
formulation and solution based on mixed
integer programming are proposed.
Preliminary simulations show the efficacy
of the optimization to schedule power
among users and appliances of a microgrid
in terms of the total power consumed and
the number of power usage requests
accepted by the system.
- Energy Aware
Cross Layer Uplink Scheduling for
Multihomed Environments
-
Takoua Ghariani
(Institut Telecom / Telecom SudParis,
France); Badii Jouaber (Institut TELECOM -
Telecom SudParis & cnrs UMR-SAMOVAR,
France)
With the continuous evolution of
wireless technologies, there is today a
plethora of access networks ranging from
wireless hotspots to high speed cellular
networks. Within this rich environment and
with multimodal terminals that are able to
connect to different wireless technologies
at once, users are expecting to benefit
from higher throughput and enhanced QoS.
However, the coexistence of several
wireless systems rises different technical
challenges including interface selection,
packet scheduling, multi-path routing and
mobility management. At the network level,
recent protocols such as MTCP and mSCTP
allow session continuity and offer the
possibility of seamlessly adapting IP
routing during a transmission session.
These protocols are mainly based on the
use of a set of IP addresses that can be
associated to the same terminal and user
session. But at the access level,
efficient packet scheduling mechanisms on
multiple interfaces are still required.
New rules and approaches are needed to
select the most suitable technology that
better fits QoS requirements considering
the dynamic mobile user environment. In
addition, optimizing energy consumption
should also be considered in order to
lengthen mobile terminals' battery
lifetime. In this paper we propose an
energy efficient cross layer scheduling
mechanism for multi-homed wireless
terminals. The proposed algorithm goes
through the use of energy models for both
802.11n and LTE technologies to
dynamically select the more suited
technology according to users' context.
Performance evaluations of the proposed
algorithm are presented and discussed.
They show that a significant energy saving
can be achieved while respecting
applications QoS requirement.
- Energy
Performance of Distributed Queuing Access
in Machine-to-Machine Networks with
Idle-to-Saturation Transitions
-
Francisco
Vázquez-Gallego (Centre Tecnològic de
Telecomunicacions de Catalunya (CTTC),
Spain); Jesus Alonso-Zarate (Centre
Tecnologic de Telecomunicacions de
Catalunya - CTTC, Spain); Pere Tuset-Peiro
(Universitat Oberta de Catalunya, Spain);
Luis Alonso (Universidad Politecnica de
Catalunya-BarcelonaTECH &
Telecommunications and Aerospatial
Engineering School of Castelldefels,
Spain)
Machine-to-Machine (M2M)
networks must be energy-efficient to
operate autonomously for years, or even
decades. In this paper, we consider a
synchronized duty-cycled M2M network
composed of a huge number of dormant
devices that periodically wake up to
transmit data to a coordinator. We propose
the use of Distributed Queuing (DQ)
tree-splitting algorithms to optimize the
shared access to the channel among the
high number of devices, in order to
improve the energy efficiency and thus
extend the network lifetime. We evaluate
the energy performance of DQ access in
this kind of dense M2M networks, and we
compare it to traditional access schemes
based on variations of Frame Slotted-ALOHA
(FSA) and the Contention Tree Algorithm
(CTA). Computer-based simulations show
that DQ can reduce the energy consumption
in more than a 50% with respect to FSA and
CTA. Results show that there is an optimum
number of contention slots which maximizes
the energy efficiency of DQ regardless of
the number of devices. The performance
evaluation presented in this paper also
compares the energy consumption of DQ
using low power Wi-Fi and IEEE 802.15.4
devices.
- Energy Aware
Evolutionary Routing Protocol with
Probabilistic Sensing Model and Wake-Up
Scheduling
-
Enan Khalil (Gazi
University, Turkey); Suat Ozdemir (Gazi
University, Turkey)
Wireless Sensor Networks (WSNs)
have become increasingly popular in recent
years for controlling systems where human
intervention is undesirable or impossible.
The main challenges in designing and
planning the operations WSNs are to
optimize the energy consumption of sensor
nodes and prolong the network lifetime.
Hierarchical routing protocols are proven
to be efficient to drastically reduce the
energy consumption and prolong the
lifespan of the network. For example,
Energy-Aware Evolutionary Routing Protocol
(EAERP) is an Evolutionary Algorithm (EA)
based routing protocol that aims to
achieve a better compromise between the
stability time and network lifetime. This
paper reformulates the design of EAERP
according to the sensing model.
Specifically, disc (isotropic) and
probabilistic sensing model are
considered. Moreover, for further
extension of network lifetime a novel
wake-up scheduling scheme applied to
alternate between active and idle state of
sensor nodes. Extensive simulations are
performed for each of sensing models and
results show that the proposed protocol
improves the energy efficiency and network
lifetime.
- Hybrid
Framework for Scalable Resource Control in
Multi-ingress Networks
-
Sandino Jardim (Federal
University of Goias, Brazil); Augusto Jose
Venancio Neto, Ph. D. (Universidade
Federal do Rio Grande do Norte &
Centro de Ciências Exatas da Terra,
Brazil); José Castillo Lema (Universidade
da Coruña, Spain); Evariste Logota
(University of Aveiro, Instituto de
Telecomunicações, Portugal); Eduardo
Cerqueira (Federal University of Para
& UFPA, Brazil); Jonathan Rodriguez
(Instituto de Telecomunicações, Portugal)
Attempts by the research
community to meet expectations arising
from future Internet systems, and
specifically to provide Quality of Service
(QoS) for multimedia multi-user sessions,
have resulted in mechanisms such as
Multi-User Aggregated Resource Allocation
(MARA). Its results have been promising,
mainly because it drastically reduces
signaling and processing overhead, despite
its limitations in multi-ingress
scenarios. In view of these benefits, this
paper proposes the Multi-User Aggregated
Resource Allocation - Multi-Ingress to
overcome the main limitations of MARA so
that it can serve as a promising tool in
todays and future IP-based network
systems. The simulation experiments
carried out for MARA-MI demonstrated the
benefits in optimizing bandwidth use and
networking costs while maintaining QoS
over time in multiple sessions, in
comparison to a relevant related work.
11:30 - 12:30
MENS 1-2:
SDN & Openflow, and Network Virtualization
- Software
Defined Networking for Distributed
Mobility Management
-
Yuhong Li (Beijing
University of Posts and
Telecommunications, P.R. China); Haimeng
Wang (Beijing University of Posts and
Telecommunications, P.R. China); Ming Liu
(Beijing University of Posts and
Telecommunications, P.R. China); Bufan
Zhang (Beijing University of Posts and
Telecommunications, P.R. China); Huanqun
Mao (Beijing University of Posts and
Telecommmunications, P.R. China)
With the mobile network core
evolving towards an unlayered and
decentralized architecture, distributed
mobility management appears to be more
compatible and efficient with the
flattened networks. In this paper, we
propose a new approach to realize the
distributed mobility management using the
software defined networking techniques
instead of the existing mobility
management protocols. The mobility
management functions are implemented with
the help of distributed controllers. The
controllers will update the involved
routing tables directly in case of
handover, which realizes the route
optimization inherently. The test results
show that the proposed SDN-aided approach
is an efficient mechanism for distributed
mobility management.
- Managing
Storage Flows with SDN Approach in I/O
Converged Networks
-
Osamu Shiraki (Fujitsu
Laboratories Ltd., Japan); Yukihiro
Nakagawa (Fujitsu Laboratories Ltd.,
Japan); Kazuki Hyoudou (Fujitsu
Laboratories Ltd., Japan); Shinji
Kobayashi (Fujitsu Laboratories Ltd.,
Japan); Takeshi Shimizu (Fujitsu
Laboratories Ltd., Japan)
The demand for efficient use of
ICT resources has recently been growing.
Equipment costs at datacenters have been
reduced to satisfy this demand and all ICT
resources have been required to be
controlled on demand. Network
virtualization and software defined
networking (SDN) technologies have been
applied to datacenter networks for the
same reason. On the other hand, efficient
networks and operations also need to be
provided, including traditional storage
systems. Ethernet fabric and I/O
convergence have been applied to satisfy
these requirements. However, the SDN
approach has mainly been applied to local
area networks and flexible control has so
far not been accomplished for converged
networks. We introduced an SDN approach
similar to OpenFlow and applied this to
Fibre Channel over Ethernet (FCoE)
networks, which is a method of achieving
I/O converged networks. This method of
controlling flows can coexist with
OpenFlow based SDN flow control.We explain
the differences between our method of flow
control, OpenFlow, and path optimization
with FCoE and their effects as examples in
this paper.
- Cloud-Based
Building Management Systems using
Short-term Cooling Load Forecasting
-
Jaehak Yu (Electronics
and Telecommunications Research Institute,
Korea); MyungNam Bae (Electronics and
Telecommunications Research Institute,
Korea); HyoChan Bang (ETRI, Korea); Sejin
Kim (University of British Columbia,
Canada)
In this paper, we propose a
novel cloud-based building management
system (BMS) architecture for a short-term
cooling load forecasting mechanism to
manage the building cooling system (BCS)
and reduce the cost of BCS construction
and maintenance. The BCS is very important
to economize on air conditioning since a
huge amount of energy is consumed by the
cooling system of buildings in summer and
some recent work have attempted to manage
the BCS using short-term cooling load
forecasting. In order to have accurate
forecasts, however, excellent computing
systems are necessary to predict and
control the BCS based on a huge amount of
past energy consumption data with rapid
processing speed. In the proposed
architecture, hence, we use centralized
computing resources and storages to
predict and control the BCS. Further, we
propose a model with short-term cooling
load forecasting and semantic analysis
system that uses data mining techniques to
improve the forecasting accuracy. Through
our performance results, the proposed
forecasting model outperforms another
scheme in terms of the forecasting
accuracy to control the BCS and it is
expected that the cost of the BCS
maintenance will be greatly reduced with
the cloud-based BMS architecture.
- Cache
management algorithm of load balancer for
large-scale SNMP monitoring system
-
Taeyoung Song (The
University of Tokyo, Japan); Yoshihiro
Kawahara (The University of Tokyo, Japan);
Tohru Asami (The University of Tokyo,
Japan)
Large-scale centralized network
management such as cloud computing,
software defined network (SDN) and network
virtualization are becoming popular. This
requires appropriate interface devices to
incorporate these new devices with legacy
devices for the large-scale network
management. To accommodate the existing
communication devices which are not
expected to manage a large network, a
centralized control monitoring will be
required. We propose a cache management
algorithm in order to avoid the problem of
increasing load by monitoring existing
network equipments. We propose a
Tambourine cache control method which
controls Time-to-Live(TTL) in a similar
way that TCP adjusts the congestion window
size. This method is able to keep CPU
utilization of SNMP devices below a
certain value and guarantees the
granularity of monitoring interval. We
show this architecture can be applied with
the general load balancer using
content-aware switching.
MENS 2-2:
Energy efficiency for emerging networks
- Impact of
Communication Availability in a
Demand-Side Energy Management System:
Differential Game-Theoretic Approach
-
Ryohei Arai (Kyoto
University, Japan); Koji Yamamoto (Kyoto
University, Japan); Takayuki Nishio (Kyoto
University, Japan); Masahiro Morikura
(Kyoto University, Japan)
Differential games are
multi-agent versions of optimal control
problems, which have been used for
modeling control systems of smart grids.
Thus, a differential-game theoretic
approach is a very promising way to
discuss a demand-side energy management
system where there are multiple
decision-making entities. This paper first
indicates that the optimal demand-side
management of multiple demand-side actors
(e.g., consumers, houses, buildings,
communities) in a decentralized way is
formulated as a differential game. In
addition, we point out that an information
structure (e.g., open-loop, feedback),
that is the most important property of
differential games, corresponds to
availability of communications. When
information shared by communications is
available, it enables demand-side actors
to act in an appropriate manner, i.e.,
demand-side actors conduct decentralized
feedback control. On the other hand, when
shared information is unavailable due to
communication failure, demand-side actors
do not necessarily give up control and
they may use another type of control, such
as prediction-based control. For example,
demand-side actors are assumed to manage
the power consumption to minimize
disutility and the electricity rates
allocated to the power grid, and to
maintain the demand-supply balance by
considering a photovoltaic power
generation. Numerical analyses demonstrate
that the proposed framework enables a
trade-off analysis for decentralized
controls considering the availability of
shared information.
- Lyapunov
Stability Analysis of Load Balancing in
Datacenter Networks
-
Amrith Dhananjayan
(Nanyang Technological University,
Singapore); Kiam Tian Seow (Nanyang
Technological University, Singapore);
Chuan Heng Foh (University of Surrey,
United Kingdom)
Modern datacenters are becoming
increasingly complex, with datacenter
networks (DCN's) built to meet the data
transmission demands of densely
interconnected nodes of server hosts and
switches. Load balancing in DCN's - to
balance the bandwidth utilization among
the DCN links - is indispensable for
meeting important objectives such as
maximizing throughput and minimizing
latency. Simulation has been the de facto
empirical method for investigating the
stability of DCN's under load balancing
policies. To complement simulation with
analytical insights into load balancing
stability of DCN's, in this paper, we
present an application of the qualitative
version of the Lyapunov stability theory
for load balancing DCN's modeled as
discrete-event systems. The general
Lyapunov control theory states that a
controlled system is stable if there
exists a function on the state space of
the system, called the Lyapunov function,
whose value is non-increasing along any
execution trajectory of the system.
Analytically proving the existence of such
a Lyapunov function is sufficient to
verify that the DES model representing a
class of DCN's under a load balancing
policy is stable. We illustrate the
utility of our approach by investigating
the stability of a class of DCN's
configured in a fat-tree topology under a
specific load balancing policy. Our work
represents the first step towards a
general qualitative stability theory for
the policy design of load balancing
algorithms for DCN's.
- Make-Without-Break
Horizontal IP Handovers for Distributed
Mobility Management Schemes
-
Tiago Silvestre
Condeixa (Instituto de Telecomunicações,
Portugal); Lucas Guardalben (University of
Aveiro, Instituto de Telecomunicacoes,
Portugal); Tomé Gomes (Instituto de
Telecomunicações, Portugal); Susana
Sargento (Instituto de Telecomunicações,
Universidade de Aveiro, Portugal); Rute C.
Sofia (SITI, Universidade Lusófona,
Portugal)
There is a new trend to consider
Distributed Mobility Management (DMM) for
flat network architectures to cope with
the increased distributed nature of the
mobile networks. DMM improves the routing
optimization and reduces the scalability
issues when compared with the centralized
mobility management, through the traffic
anchoring distribution at the Access
Routers (ARs). However, the handover
optimization, which also demands for fast
and soft handovers to reduce/eliminate the
handover latency and the respective packet
loss, is not properly addressed in the
DMM. Although current seamless handover
approaches, already integrated in
centralized mobility schemes, could also
be adapted to the DMM schemes, they
introduce new entities/functionalities,
messages and buffering/bicasting
mechanisms to reduce the handover latency
or the packet loss. In this paper, the
seamless IP handover is addressed from a
novel make-without-break perspective,
which is able to maintain two logical
connections in the same physical interface
with two Access Points (APs) from distinct
IP networks. The outcome of the evaluation
shows that make-without-break with a DMM
scheme is able to reduce or even eliminate
the handover latency and the packet loss
from link disconnection, providing
seamless IP session continuity in mobile
environments.
- Efficient
Traffic Allocation Scheme for Multi-flow
Distribution in Heterogeneous Networks
-
Hao Lian (Beijing
Uninversity of Posts and
Telecommunications, P.R. China); Xiao Yan
(Beijing University of Posts and
Telecommunications, P.R. China); Lina Weng
(Beijing University of Posts and
Telecommunications, P.R. China); Qixun
Zhang (Beijing University of Posts and
Telecommunications, P.R. China); Zhiyong
Feng (Beijing University of Posts and
Telecommunications, P.R. China); Ping
Zhang (WTI-BUPT, P.R. China)
This paper proposes an efficient
dynamic traffic allocation scheme for
multi-flow distribution in LTE-WLAN
heterogeneous networks, where data traffic
is split into multiple sub-flows and
transmitted through different networks
simultaneously. The state transition
equations of the M/M/1 queuing system are
modified to model the parallel
transmissions. To improve system
performance especially in practical
situations, our modified queuing system
model also considers random interference
and dynamic changes of available bandwidth
which are often ignored in previous work.
We also study the traffic characteristics
to ameliorate the trade-off between
limited network resources and multiple
flow transmission. A novel scheme —
layered video streaming allocation (LVSA)
— based on traffic characteristics is
proposed to increase system capacity
especially in high delay situations.
Simulation results indicate that our
schemes have a significant improvement in
delay performance and system capacity
compared with other schemes.
- Optimal
Spectrum Decision with Channel Quality
Considered in Cognitive Radio Subnets
-
Mingxue Liao (Institute
of Software, Chinese Academy of Sciences,
P.R. China); He Xiao-Xin (Institute of
Software, Chinese Academy of Sciences,
P.R. China); Fanjiang Xu (Institute of
Software Chinese Academy Sciences, P.R.
China)
This paper formulates a new QoS
model for a tree-based cognitive radio
network (CRN) which is under test for
communication in mountainous areas. The
model takes spectrum quality into account,
which results in a more complex spectrum
decision involving 3-dimension
information: cognitive users, spectrums
and their quality for combination
optimization making. An optimal algorithm
with correctness and performance proofs is
proposed to search the best solution among
all possible candidates. Each candidate
takes a form of extreme maximal bicliques
(EMB) in a viewpoint of cognitive users
and spectrums, or a user-spectrum space
and the best one adds more rich features
to EMB. Simulations with parameters
coinciding with real application
requirements and experiment data from many
days of experiments are conducted, showing
a real-time performance of the algorithm.
13:30 - 14:45
Keynotes
2: Q&A Panel with Industry: IPv6, SDN &
NFV, Autonomic & Converged Management
- Implementation
Guide for the ETSI AFI GANA Model: a
Standardized Reference Model for Autonomic
Networking, Cognitive Networking and
Self-Management
-
Ranganai Chaparadza
(IPv6 Forum, Germany); Tayeb Ben Meriem
(Orange, France); Benoit Radier (Orange
France Telecom R&D, France); Szymon
Szott (AGH University of Science and
Technology, Poland); Michal Wodczak
(Department of Information Technology at
Poznan University of Economics, Poland);
Arun Prakash (Fraunhofer FOKUS &
Technische Universität Berlin, Germany);
Jianguo Ding (University of Skövde,
Sweden); Andrej Mihailovic (King's College
London, United Kingdom); Said Soulhi
(Ericsson, Sweden)
This paper is standardization
oriented paper that describes an
Implementation Guide for an emerging
standard for autonomic management
&control, namely the ETSI AFI GANA
Reference Model for Autonomic Networking,
Cognitive Networking and Self-Management
(an emerging standard from ETSI). The
implementation guide also takes into
consideration the impact of emerging
paradigms such as SDN and Virtualization.
This is because as the standardized
Reference Model has been published, it
becomes important to provide an associated
Implementation Guide that can be followed
in implementing autonomic management &
control in architectures.
14:45 - 15:30
MENS:3:
LTE Technology and Management & Control
- A Delay
Sensitive LTE Uplink Packet Scheduler for
M2M Traffic
-
Nusrat Afrin
(University of Newcastle, Australia);
Jason Brown (University of Newcastle,
Australia); Jamil Y Khan (The University
of Newcastle, Australia)
Some M2M applications such as
those found in a Smart Grid environment
generate event driven and delay sensitive
uplink traffic. Wide area cellular systems
such as LTE are usually not optimized for
such traffic. In this paper, we design an
LTE scheduler with the main objective of
maximizing the percentage of uplink
packets that satisfy their individual
delay budgets. In order to do this
accurately, we allow devices to notify the
eNodeB of the age of the oldest packet in
their buffers via a new MAC control
element in the uplink MPDU. This
information is used by the eNodeB to
calculate an absolute deadline for each
packet request individually, and the
eNodeB scheduler ranks requests according
to an urgency metric that depends upon the
time remaining to the deadline and other
factors such as the volume of pending data
in the device buffers. Using an OPNET
simulation model of an LTE TDD system, we
show that our proposed scheduler can
satisfy the uplink delay budget for more
than 99% of packets for bursty delay
sensitive M2M traffic even when the system
is fully loaded with regard to the data
channel utilization.
- Adaptive
QoS-Aware Resource Allocation for
High-Speed Mobile LTE Wireless Systems
-
Yifan Zhang (Beijing
University of Posts and
Telecommunications, P.R. China); Muqing Wu
(BUPT, P.R. China); Rui Zhang (Beijing
University of Posts and
Telecommunications, P.R. China); Panfeng
Zhou (Beijing National Railway Research
& Design Institute of Signal &
Communication, P.R. China); Shiping Di
(Beijing National Railway Research &
Design Institute of Signal &
Communication, P.R. China)
Resource allocation is one of
the key issues in long term evolution
(LTE) systems. In this paper, we propose
an adaptive resource allocation scheme
with quality of service (QoS) guarantees
to maximize system throughput for
high-speed mobile LTE systems. In this
scheme, considering that channel quality
indicator (CQI) might be changed in fast
mobile scenarios which can reduce the
system throughput, we first propose a
novel CQI feedback method to achieve
continue high throughput. Then we optimize
the resource blocks (RB) allocation
procedure under QoS requirements and adopt
a more effective modulation and coding
scheme (MCS) selection method to improve
the system performances. Through extensive
simulations, the results show that the
proposed resource allocation scheme can
achieve higher system throughput and
better performance stability compared with
some existing schemes in high-speed mobile
LTE systems.
- Joint
implementation of Several LTE-SON
Functions
-
Khoa Truong Dinh
(Warsaw University of Technology, Poland);
Sławomir Kukliński (Warsaw University of
Technology, Poland)
In SON enabled LTE networks many
different SON functions may operate
simultaneously in order to optimize the
entire network performance. With the
increasing number of SON functions the
probability of conflicts and dependencies
between them increases and become more
challengeable to handle. In this paper an
integrated approach for two SON functions,
namely handover optimization and load
balancing combined with admission control
is presented. In this approach the
conflicts are solved using the combination
of Fuzzy Q-Learning Control (FQLC)
algorithm and a heuristic Diff_Load
algorithm. The novelty of this approach
lies in using of FQLC for adjusting more
than a single parameter, namely the
handover hysteresis and the time to
trigger. Working in parallel, the
Diff_Load tunes the handover offset. The
proposed approach has been evaluated using
the LTE-Sim simulator.
- Selective
Call-Dropping and Bandwidth Adaptation for
Reducing Multiple-Call Handoff Dropping
-
Olabisi Emmanuel Falowo
(University of Cape Town, South Africa)
Small cells such as femto cells
are commonly being deployed for traffic
offloading in heterogeneous wireless
networks (HetNet), and multimode terminals
designed for HetNets have the capability
to simultaneously support two or more
different classes of calls. A user having
a multimode terminal with multiple ongoing
calls that are connected through a femto
cell may experience necessary handoff when
the user moves outside the coverage area
on the femto cell in a HetNet. However,
multiple handoff calls from a multimode
terminal may be dropped because none of
the available candidate radio access
technologies has enough residual capacity
to accommodate the multiple handoff calls
from the femto cells. In order to reduce
the probability of dropping multiple
handoff calls in HetNets, this paper
proposes a handoff decision scheme that
uses selective call dropping and bandwidth
adaptation to decrease overall call
dropping probability of multiple handoff
calls. The proposed scheme uses individual
call priority for performing selective
call dropping. Performance of the proposed
scheme is evaluated and compared for four
different scenarios. Results show that the
proposed scheme significantly reduces the
probability of dropping essential handoff
calls in HetNet.
MENS:4:
QoS and performance optimization
- Decoupling
Malicious Interests from Pending Interest
Table to Mitigate Interest Flooding
Attacks
-
Kai Wang (Beijing
Jiaotong University, P.R. China); Huachun
Zhou (Beijing Jiaotong University, P.R.
China); Yajuan Qin (Beijing Jiaotong
University, P.R. China); Jia Chen (Beijing
Jiaotong University, P.R. China); Hongke
Zhang (Beijing Jiaotong University, P.R.
China)
Named Data Networking (NDN) is a
clean slate Internet paradigm that embeds
some security primitives in its original
design, which is being considered as one
of the promising candidates for
next-generation Internet architecture.
However, it may suffer from some emerging
threats such as Interest Flooding Attacks
(IFA), which means corresponding security
management mechanisms need to be designed
to improve its security. In this paper, we
focus on the IFA that can severely consume
the memory resource for the Pending
Interest Table (PIT) of each involved NDN
router by flooding large amount of
malicious Interests with spoofed names. To
loosen the stress of PIT attacked by IFA,
we propose an approach called Disabling
PIT Exhaustion (DPE) to divert all the
malicious Interests out of PIT, by
directly recording their state information
(e.g., incoming interface) in the name of
each malicious Interest rather than PIT,
as well as introducing a packet marking
scheme to enable Data packet forwarding
without the help of PIT. DPE can be
considered as a security management
mechanism for the emerging NDN
architecture, which aims at reducing
memory resource consumption for each NDN
router. Moreover, we present an in-depth
evaluation on DPE, via extensive
simulations under realistic users'
behavior model. Simulation results show
DPE can significantly mitigate the damage
effect of IFA on exhausting PIT's memory
resource. To the best of our knowledge,
DPE is the first attempt to design a
security management mechanism embedding
with the idea "decoupling malicious
Interests from PIT" to counter IFA.
- Performance
comparison of Routing Protocols over Smart
Utility Networks: A Simulation Study
-
Gopalakrishnan B Iyer
(Auburn University, USA); Prathima Agrawal
(Auburn University, USA); Ruben Salazar
Cardozo (Landis + Gyr, USA)
With the rapid increase in
deployment of smart meters across North
America, utility resources such as water,
gas and electricity consumption data is
being collected at a much higher granular
level. The huge amount of data is being
used to make demand-response applications
smarter. A large part of this deployment
of smart utility networks and Advanced
Metering Infrastructure (AMI) is being
done using the wireless mesh architecture
due to the low deployment costs offered by
this method. Although wireless environment
parameters such as fading and path loss
differ widely from home, outdoor to
industrial, in-building scenarios,
efficient protocols at the Medium Access
Control (MAC) and Physical (PHY) layers
and lower layer agnostic data routing
protocols can be employed to overcome
these challenges. For such routing
protocols to be applicable to smart
utility networks, reliability and
scalability are vital metrics which will
determine the performance in such
networks. In this paper, we analyze
reliability and scalability of three such
routing protocols, viz. RPL (IPv6 Routing
Protocol for Low power and Lossy
Networks), LOAD (6LoWPAN Ad Hoc On-Demand
Distance Vector Routing) and a proprietary
flavor of Geographical Routing.
- Congestion
Control and User Utility Function for
Real-Time Traffic
-
Hengky Susanto
(University of Massachusetts at Lowell,
USA); Byung-Guk Kim (University of
Massachusetts at Lowell, USA)
Usage of multimedia
communication in everyday life has seen a
remarkable growth. Vast in Bandwidth
demand often result in lower network
performance and reduced quality of user
experience during congestion. In this
paper, we will address congestion control
problem while providing quality of service
(QOS) of delay for inelastic flows like
video streaming, IPTV, etc. First, we
propose an extension of an existing user
utility function [2] to capture user's
satisfaction over bandwidth allocation,
QoS, and the cost to acquire the service.
Second, we will study the relationship
between these three entities.
- Square-Based
Location Update Protocol in Wireless
Sensor Networks
-
Jun Xu (Information
& Electronics Technology Lab, Beijing
University of Posts and
Telecommunications, P.R. China); Zhiqiang
Liu (Beijing University of Posts and
Telecommunications, P.R. China); Weidong
Wang (Beijing Unversity of Posts and
Telecommunications, P.R. China); Yinghai
Zhang (Beijing University of Posts and
Telecommunications, P.R. China)
The introduction of mobile sink
to wireless sensor networks (WSNs) can
effectively address the hot-spot problem.
However, as the sink moves in the sensing
area, its location information needs to be
broadcasted periodically to ensure network
connectivity. This additional location
update process will increase communication
cost in each sensor node. To deal with
this problem, this paper proposes a
Square-Based Location Update Protocol
(SLUP). In SLUP, the target area is
divided into squares and subdivided into
virtual grids. The sink does not need to
broadcast its location information to the
entire network when it only moves inside a
square. Besides, the pattern of sink
mobility is determined by real-time
network parameters, e.g., Average Residual
Energy of Sensor Nodes (ARESN) and sojourn
time in a square. Such controlled mobility
pattern can not only decrease the
probability of moving out of the current
square for the sink but also achieve load
balancing in the network. Simulation
results demonstrate that SLUP outperforms
the traditional protocols in reducing the
energy consumption of location update and
prolonging the network lifetime.
15:30 - 16:00
Coffee
break
16:00 - 17:00
MENS 5:
Management of Emerging Networks
- A New Approach
for Scrambling and Spreading Code Reuse in
WCDMA Networks
-
Rouzbeh Razavi (Bell
labs, Alcatel-Lucent, Ireland); David
López-Pérez (Bell Labs Alcatel-Lucent,
Ireland); Holger Claussen (Bell Labs,
Alcatel-Lucent, Ireland)
In this paper, we propose a
novel approach for addressing both
inter-cell interference and handover
failure issues in dense WCDMA small cell
deployments. This is achieved through an
innovative scrambling allocation approach
and an efficient spreading code allocation
scheme that allow appropriate spatial
reuse of resources. The proposed
enhancements can be implemented in a
centralised or distributed manner, and
they are standard compliant. Simulation
results show that the proposed approach
can significantly mitigate inter-cell
interference in both data and control
channels, and thus result in enhanced
network and user capacity as well as
mobility management in dense small cell
clusters.
- Churn
Prediction in Subscriber Management for
Mobile and Wireless Communications
Services
-
Hakki Candan Cankaya
(Fujitsu Network Communications &
Southern Methodist University, USA); Utku
Yabas (Engineer, USA)
Subscriber churn is a concern of
customer care management for most of the
mobile and wireless service providers and
operators due to its associated costs.
This paper explains our work on subscriber
churn analysis and prediction for such
services. We work on data mining
techniques to accurately and efficiently
predict subscribers who will
change-and-turn (churn) to another
provider for the same or similar service.
The dataset we use is a public and real
dataset compiled by Orange Telecom for the
KDD 2009 Competition. Number of teams
achieved high scores on this dataset
requiring a significant amount of
computing resources. We are aiming to find
alternative methods that can match or
improve the recorded high scores with more
efficient and practical use of resources.
In this study, we focus on ensemble of
meta-classifiers which have been studied
individually and chosen according to their
performances.
- XML-compression
techniques for efficient network
management
-
Antonio Dariush
Kheirkhahzadeh (University of West London,
United Kingdom); John Moore (University Of
West London, United Kingdom); Jiva Bagale
(University Of West London, United
Kingdom)
XML has become a standard widely
used in wireless networking technologies
to improve flexibility and
interoperability between heterogeneous
applications. However, applying this
technology to areas such as network
management across a wireless embedded
internet can pose significant challenges
due to the verbosity of XML. A number of
compression techniques and tools have been
applied to this problem to help transform
highly-structured data into a more compact
form. Despite this choice, there is a lack
of support for tools which are optimised
for embedded computing. In this paper we
will show the performance trade-offs that
exist when compression is applied using
different techniques. Furthermore, we will
describe a tool which has been specially
designed to be used within the domain of
network management within a constrained
environment.
- On the
Analysis of Dissemination Management
Information through an Eyesight
Perspective
-
Lucas Guardalben
(University of Aveiro, Instituto de
Telecomunicacoes, Portugal); Tiago
Silvestre Condeixa (Instituto de
Telecomunicações, Portugal); Tomé Gomes
(Instituto de Telecomunicações, Portugal);
Paulo Salvador (Instituto de
Telecomunicações, DETI, University of
Aveiro, Portugal); Susana Sargento
(Instituto de Telecomunicações,
Universidade de Aveiro, Portugal)
The dissemination of information
in wireless networks is a fundamental
aspect in several network processes, such
as routing, monitoring and management.
Nowadays, most of the techniques for
dissemination of management information
adopt controlled flooding approaches,
which usually impairs the network
performance. In this sense, the
optimization of the dissemination of
management information for large-scale
wireless scenarios remains a relevant
research challenge. In this paper, it is
presented and analyzed the performance of
the Neighbors Eyesight Direction (NED)
dissemination against to OSPF,
uncontrolled flooding and Gossip
approaches in wired and large network
scenarios. NED is able to work on wired
and large-scale wireless scenarios,
showing to be more efficient than the
baseline approaches. With lower
dissemination cost and lesser recursive
cycles, NED proved to be scalable to
disseminate management information for
scenarios with a large number of devices.
- Router-based
Request Redirection Management for Next
Generation Content Distribution Network
-
Erwin Harahap (Keio
University, Japan); Janaka Wijekoon (Keio
University, Japan); Rajitha Tennekoon
(Keio University, Japan); Fumito Yamaguchi
(Keio University & Graduate School of
Science and Technology, Japan); Hiroaki
Nishi (Keio University, Japan)
The increase of digital data
between content's servers and clients in a
network causes congestion problems when
downloading big web contents including
files, streaming media, etc. Content
Delivery Network (CDN) is introduced to
overcome such problems by redirecting
client's request to a nearest server.
However, with intensity increasing number
of people accessing internet, the
performance of CDN is reduced and
sometimes congested. We propose an
architecture to solve such problems with a
new management method to redirect client's
request through a router. This method is
more effective than the traditional
DNS-based redirection that is currently
being used. We introduce a special router
named as Service-oriented Router (SoR)
that can perform a deep packet inspection
(DPI) into the packet streams. Our
experiment conducted with both analytical
modeling as well as test bed experiments
which confirmed that the router-based
request redirection management reduced the
response time by 23.3% and test bed RTT
7.7% compared to the DNS-based request
redirection management.
MENS 6:
Autonomic networking, cognitive networking and
self-Management
- The Role of
SDL in the Design, Simulation, Validation
of System Models, and Code-Generation, in
the recently emerged and growing domain of
Autonomic Systems Engineering
-
Ranganai Chaparadza
(IPv6 Forum, Germany); Arun Prakash
(Fraunhofer FOKUS & Technische
Universität Berlin, Germany)
In this paper we present the
role of SDL in the recently emerged and
growing domain of autonomic systems
engineering, in which SDL has a role to
play. The topic and issues discussed in
this paper are important because the
subject of the role of SDL in autonomic
systems engineering has not yet been
explored due to the fact the area of
autonomic systems engineering is still a
growing even though it is now a mature
area. In this paper we investigate the
role SDL should play in autonomic systems
engineering. At the same time we raise a
series of questions we believe both the
research community and the industry at
large needs to consider in this context
and come up with solutions that will
solidify the role of SDL in such emerging
domains. While we provide important
insights, the goal is not to provide
answers to each of the questions we raise
in this study, but rather to discuss
issues that both academia and industry
should seize within this growing area. The
domain of Autonomic Networking is now
seeing a Reference Model that defines the
associated concepts of the domain, their
relationships and constraints, being
developed in ETSI - European
Telecommunications Standards Institute.
Thus, in this paper, we argue the need for
the formalization of the Reference Model
as a standardizable Meta-Model and present
the role of SDL in a model-driven systems
engineering methodology and associated
tool-chain for designing stable autonomic
systems.
- Autonomic
Cooperative Behaviour in ETSI AFI Scenario
for Autonomicity Enabled Ad-hoc and Mesh
Network Architecture
-
Michal Wodczak
(Department of Information Technology at
Poznan University of Economics, Poland);
Ranganai Chaparadza (IPv6 Forum, Germany);
Szymon Szott (AGH University of Science
and Technology, Poland)
This paper discusses the ETSI
AFI (Autonomic network engineering for the
self-managing Future Internet) dedicated
scenario for the deployment of Autonomic
Cooperative Behaviour (ACB) for the needs
of the instantiation of Autonomicity
Enabled Ad-hoc and Mesh Network
Architecture. An inherent feature of ACB
is the use of cooperative data processing
and computing among network devices for
the purposes of improving the related
system robustness and dependability. In
fact, as much as they may be
differentiated, both ad-hoc and mesh
networks share certain common aspects
allowing for the application of the
assumed scenario in the case o each of
them. This approach aims to guarantee
certain level of unification in terms of
standardisation and validation, especially
that the scenario is very demanding due to
the existence of numerous walls impeding
the quality of data transmission and,
thus, calling for ACB as a remedy.
- Proxy based
Distributed Mobility Management in PURSUIT
-
Zhiwei Yan (CNNIC, P.R.
China); Yong Jin Park (Waseda University,
Japan); Jong-Hyouk Lee (Sangmyung
University, Korea); Xiaodong Lee (CNNIC,
P.R. China)
The Publish-Subscribe Internet
Technology (PURSUIT) project aims at
developing a new internetworking
architecture for the Future Internet. The
internetworking architecture of PURSUIT
has adopted a Publish-Subscribe Internet
(PSI) architecture that is one of the most
promising approaches to solve the current
Internet's limitations including mobility
support. In this paper, a new mobility
support scheme is introduced to provide
better handover performance for the PSI
architecture. In the proposal, a branching
point in a network is dynamically selected
as a proxy to support seamless handover.
The proxy duplicates packets (i.e.,
contents) from a content source to a new
attachment point of a subscriber.
Numerical results show that the proposed
scheme provides better handover
performance compared to that of the basic
PSI architecture in terms of handover
latency. The required handover preparation
time and signaling cost of the proposed
scheme are also analyzed objectively.
- Knowledge
Functional Block for E-UTRAN
-
Aimilia Bantouna
(University of Piraeus &
Telecommunication Networks and integrated
Services Laboratory, Greece); Kostas
Tsagkaris (University of Piraeus, Greece);
Panagiotis Demestichas (University of
Piraeus, Greece)
Large availability of digital
data, or else Big Data, offers to data
scientists the chance of exploiting them
and building knowledge on different
aspects of everyday life related to e.g.,
people preferences and habits,
transportation, health systems,
telecommunications etc. This study targets
to exploit this opportunity in the
telecommunications era. Towards this
direction, the paper presents the
architectural aspects, the role and the
foundation of the functionalities of the
knowledge functional block. Knowledge
functional block comprises of knowledge
building mechanisms that learn different
aspects of future wireless networks in
order to enhance their decisions and thus
their functionality. These aspects may
involve context, efficiency of the
decisions, energy efficiency, trust and
others. Data that can be directly
monitored from an Evolved Universal
Terrestrial Radio Access Network (E-UTRAN)
are identified and modeled to guide the
input that can be used for the knowledge
building mechanisms of the block.
- Asymptotic
Performance Analysis for Common Data
Delivery in Cognitive Radio Networks
-
Kewen Yang (Beijing
University of Posts and
Telecommunications, P.R. China); Wenjun Xu
(Beijing University of Posts and
Telecommunications, P.R. China); Shengyu
Li (Beijing University of Posts and
Telecommunications, P.R. China); Qian Wan
(Beijing University of Posts and
Telecommunications, P.R. China); Kai Niu
(Beijing University of Posts and
Telecommunications, P.R. China); Jiaru Lin
(Beijing University of Posts and
Telecommunications, P.R. China)
This paper investigates the
asymptotic throughput performance of
common data delivery in cognitive radio
networks (CRNs). Three schemes, named
unicast, conventional multicast (CM) and
Multiple Description Coding Multicast
(MDCM), are compared by utilizing extreme
value theory. The distributions of
effective signal-to-noise-ratio (SNR) for
unicast and CM belong to Domain of
Attraction of Gumbel distribution for
maxima and Domain of Attraction of Weibull
distribution for minima, respectively.
Based on asymptotic distribution of a
central order statistic, the asymptotic
performance of MDCM is then investigated.
We first formulate it as an optimization
problem, and then transform it into an
equivalent one and solve it efficiently.
By both theoretic derivation and
simulation analysis, it is found that when
the multicast group size grows, the
per-user throughput of both unicast and CM
decays to zero rapidly, while that of MDCM
approaches to a positive constant, which
implies that MDCM is a more promising
scheme for common information delivery in
CRNs considering that the number of users
is typically large in CRNs.
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