مجال
التميز
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تميز دراسي وبحثي + جائزة تفوقية
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البحوث المنشورة
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البحث (1):
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عنوان البحث:
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An
Efficient Scalable Scheduling MAC Protocol for Underwater Sensor Networks
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رابط إلى البحث:
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Click here
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تاريخ النشر:
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25 August
2018
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موجز عن البحث:
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Underwater
Sensor Networks (UWSNs) utilise acoustic waves with comparatively lower loss
and longer range than those of electromagnetic waves. However, energy remains
a challenging issue in addition to long latency, high bit error rate, and
limited bandwidth. Thus, collision and retransmission should be efficiently
handled at Medium Access Control (MAC) layer in order to reduce the energy
cost and also to improve the throughput and fairness across the network. In
this paper, we propose a new reservation-based distributed MAC protocol
called ED-MAC, which employs a duty cycle mechanism to address the
spatial-temporal uncertainty and the hidden node problem to effectively avoid
collisions and retransmissions. ED-MAC is a conflict-free protocol, where
each sensor schedules itself independently using local information. Hence,
ED-MAC can guarantee conflict-free transmissions and receptions of data
packets. Compared with other conflict-free MAC protocols, ED-MAC is
distributed and more reliable, i.e., it schedules according to the priority
of sensor nodes which based on their depth in the network. We then evaluate
design choices and protocol performance through extensive simulation to study
the load effects and network scalability in each protocol. The results show that
ED-MAC outperforms the contention-based MAC protocols and achieves a
significant improvement in terms of successful delivery ratio, throughput,
energy consumption, and fairness under varying offered traffic and number of
nodes.
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البحث ( 2 ):
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عنوان البحث:
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An
Energy-Conserving Collision-Free MAC Protocol for Underwater Sensor Networks
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رابط إلى البحث:
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Click here
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تاريخ النشر:
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25 February
2019
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موجز عن البحث:
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An
underwater sensor network (UWSN) has recently attracted considerable
attention due to its ability to discover and monitor the aquatic environment.
However, its acoustic communication has posed several inherent
characteristics, such as high latency, low available bandwidth, and high bit
error rate. These unique characteristics have made contention-based medium
access control (MAC) protocols inefficient for UWSNs. They are most expensive
and are not as effective as they are in terrestrial networks. Through this
principle, a contention-free MAC protocol is, therefore, considered to be
more reliable and flexible to overcome the consequences of applying acoustic
signals and also to achieve a high performance (improving the energy
efficiency and throughput across the network) by eliminating the chance of
collision. In this paper, we propose a novel energy-conserving and
collision-free depth-based layering MAC (DL-MAC) protocol for UWSNs. DL-MAC
is able to deal with the underwater MAC challenges, such as the near-far
effect, spatial-temporal uncertainty, and hidden/exposed terminal problems.
It is able to efficiently schedule the transmission and reception operations
in each side by using the concept of layering and a distributed clustering
algorithm. By using a TDMA-based principle, DL-MAC can assign separate time
slots to every sensor node individually to access the medium without any
possibility of collision. Our extensive simulation study shows that DL-MAC
outperforms other protocols in terms of throughput, packet delivery ratio,
energy consumption, and packets lost under varying traffic rates and the
numbers of nodes.
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البحث ( 3):
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عنوان البحث:
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A Collision-Free Graph Coloring MAC Protocol for
Underwater Sensor Networks
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رابط إلى البحث:
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Click here
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تاريخ النشر:
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27 March
2019
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موجز عن البحث:
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Employing contention-based medium access control
(MAC) protocols in underwater sensor networks (UWSNs) is typically costly.
This is due to the unique characteristics of underwater acoustic channels,
such as long propagation delay, limited bandwidth, and high bit error rate.
As a consequence, the contention-based (handshaking and random access-based)
MAC protocols do not perform as efficiently as expected. The collision-free
approach is therefore considered to achieve high performance by avoiding the
collisions at the MAC layer in order to improve energy efficiency,
throughput, and fairness. In this paper, we propose, inspired by the graph
coloring techniques, a novel energy-conserving and collision-free
reservation-based MAC protocol, called GC-MAC, for UWSNs. GC-MAC employs
time-division multiple access (TDMA)-like approach by assigning separate
time-slots, colors, to every individual sensor node in every two-hop
neighborhood. Sensors with the same colors can thus transmit at the same time
with no chance of collision. GC-MAC is also able to address the near–far
effect, spatial–temporal uncertainty, and hidden/exposed node problems,
without requiring code-division multiple access (CDMA) or power adjustment
for collision avoidance. The network coverage and connectivity is then
discussed to show the effectiveness of using cubes to cover a 3D underwater
environment. Our extensive performance study shows that GC-MAC performs well
by avoiding collisions to achieve better throughput and energy-efficiency
performance compared with those of contention-based protocols. There is also
a significant improvement in terms of packet delivery ratio and fairness
among the nodes under different operational conditions.
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المؤتمرات العلمية:
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المؤتمر (1):
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عنوان المؤتمر:
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IEEE
88th Vehicular Technology Conference (VTC) Fall
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تاريخ الإنعقاد:
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27–30
August 2018
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مكان
الإنعقاد:
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Chicago, USA
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طبيعة المشاركة:
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Oral presentation
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عنوان المشاركة:
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An
Energy-conserving Depth-based Layering MAC Protocol for Underwater Sensor
Networks
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ملخص المشاركة:
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Underwater
sensor networks (UWSNs) are effective tools for discovering and observing the
underwater environment. Due to the unique characteristics of its acoustic
channels such as long propagation delay, limited bandwidth, and high bit
error rate, most contention-based Media Access Control (MAC) protocols are
usually costly. As a result, both contention-based MAC protocols with and
without RTS/CTS schemes do not perform as efficiently as their achieved
performance in terrestrial networks. A collision-free approach is
increasingly considered to more likely achieve a better performance by
preventing any possibility of collisions in order to improve the energy
efficiency and throughput across the network. In this paper, we propose a
novel energy-conserving and collision-free depth-based layering MAC protocol,
called DL-MAC, for UWSNs. Through multiple layers and distributed clustering
approach, DL-MAC successfully schedules reception and transmission periods
according to nodes priority in the network. It also addresses the
spatial-temporal uncertainty, near-far, and hidden/exposed terminal problems.
Our extensive simulation study shows that DL-MAC outperforms previously
reported protocols in terms of throughput, packet delivery ratio, energy
consumption, and fairness under varying offered loads. Index Terms-Underwater
sensor networks (UWSNs), Media access control (MAC), Depth-based scheduling,
Multiple layer division, Cluster-based approach, Collision-free MAC protocol.
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المؤتمر (2):
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عنوان المؤتمر:
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8th
International Conference on Sensor Networks
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تاريخ الإنعقاد:
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26–27
February 2019
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مكان
الإنعقاد:
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Prague, Czech Republic
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طبيعة المشاركة:
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Oral presentation
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عنوان المشاركة:
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A
Comparative Performance Evaluation of Distributed Collision-free MAC
Protocols for Underwater Sensor Networks
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ملخص المشاركة:
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The
design of Medium Access Control (MAC) protocols for UWSNs poses many
challenges because of their long propagation delay, high mobility, limited
bandwidth, and high bit error rate. Due to these unique acoustic channel
characteristics, most contention-based MAC protocols are costly. Thus,
collisions and retransmissions should be efficiently handled at the MAC layer
in order to reduce the energy cost and to improve throughput and fairness
across the network. As a consequence, they do not perform as efficiently as
their achieved performance in terrestrial networks. In this paper, we
evaluate the performance of three recently reported distributed
collision-free MAC protocols; namely, ED-MAC, DL-MAC, and GC-MAC under
various operational conditions. An extensive simulation study is carried out
to compare the performance of these MAC protocols in terms of packet delivery
ratio (PDR), throughput, and energy consumption with different scenarios
(narrow and shallow networks) under varying traffic rates and numbers of
nodes. Our study results showed that ED-MAC reaches the best energy
efficiency in a narrow scenario with a light load than DL-MAC and GC-MAC
protocols. While DL-MAC is a suitable choice for both scenarios among others
in terms of flexibility. In terms of reliability and scalability, GC-MAC
achieves the best performance in both scenarios than other protocols.
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المؤتمر (3):
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عنوان المؤتمر:
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19th International
Conference on Network-Based Information Systems (NBIS)
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تاريخ الإنعقاد:
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07-09
September 2016
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مكان
الإنعقاد:
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Ostrava, Czech Republic
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طبيعة المشاركة:
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Oral presentation
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عنوان المشاركة:
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Performance
Comparison of Sender-based and Receiver-based Scheduling MAC Protocols for
Underwater Sensor Networks
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ملخص المشاركة:
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Underwater
Sensor Network (UWSN) is significantly different from terrestrial network in
that acoustic signal is mainly used as the communication medium. The acoustic
signal imposes high bit error rate, limited bandwidth and long propagation
delay which, to some extent, influences the design of various services in
UWSNs. MAC protocol, however, is one of the protocols which has been
completely affected by the unique features of underwater environment. For
UWSNs, energy-efficiency is now a major concern due to difficulties of
replacing or recharging batteries. In order to save energy, most of the
proposed MAC protocols follow a pattern of sleeping and listening mode, since
the sleep mode energy consumption is much less than that of the idle
listening mode. Hence, the energy efficiency is directly dependent upon how
the sleeping and listening modes are scheduled at each node. In some
protocols, sender-based scheduling, the schedule is specified by the sending
nodes, whereas in receiver-based scheduling the receiving nodes decide to
schedule data transmission. In this paper, we evaluate the UWAN-MAC, as a
sender-based, and R-MAC, as a receiver-based scheduling. Our simulation results
show that the receiver-based always performs well in terms of energy
consumption for small size networks and under light traffic. However, by
increasing the number of nodes or traffic load, the sender-based highly
outperforms the receiver-based scheduling protocols in terms of end-to-end
delay and throughput.
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المؤتمر (4):
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عنوان المؤتمر:
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Ninth
International Conference on Ubiquitous and Future Networks (ICUFN)
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تاريخ الإنعقاد:
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04-07 July
2017
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مكان
الإنعقاد:
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Milan, Italy
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طبيعة المشاركة:
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Oral presentation
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عنوان المشاركة:
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Efficient
Depth-Based Scheduling MAC Protocol for Underwater
Sensor Networks
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ملخص المشاركة:
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Underwater
Sensor Networks (UWSN) utilise acoustic waves with comparatively lower loss
and longer range in underwater environment than electromagnetic waves.
However, energy remains a challenging issue in addition to long latency, high
bit error rate, and limited bandwidth. Thus, collision and retransmission
should be efficiently handled at MAC layer in order to reduce the energy cost
and also to improve the throughput and fairness across the network. In this
paper, we therefore propose a new reservation-based distributed MAC protocol,
which employs a duty cycle mechanism to address the spatial-temporal
uncertainty and the hidden node problem to effectively reduce collisions and
retransmissions. Our extensive simulation study reveals that our proposed
protocol can efficiently handle the traffic contention to achieve significant
improvement in terms of energy consumption, throughput, and fairness.
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المؤتمر (5):
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عنوان المؤتمر:
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IEEE
32nd International Conference on Advanced Information Networking and
Applications (AINA)
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تاريخ الإنعقاد:
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16-18 May
2018
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مكان
الإنعقاد:
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Cracow, Poland
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طبيعة المشاركة:
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Oral presentation
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عنوان المشاركة:
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Graph
Colouring MAC Protocol for Underwater Sensor Networks
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ملخص المشاركة:
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Employing
contention-based MAC protocols in underwater sensor networks are typically
costly. This is mainly due to the unique characteristics of its acoustic
channels such as long propagation delay, high bit error rate, and limited
bandwidth. As a consequence, handshake-based and random access-based MAC
protocols do not perform as well as expected. The collision-free approach is
therefore considered to achieve a better performance by efficiently
addressing spatial-temporal uncertainty, hidden/exposed terminal problems,
and near-far effect at MAC layer, thus collisions and retransmissions are
properly avoided in order to reduce the energy cost and also to improve the
throughput and fairness across the network. In this paper, we propose a novel
energy-conserving and collision-free graph colouring MAC protocol, called
GC-MAC, for UWSNs. It employs a TDMA-like principle by assigning separate
time slots to every individual colour in the network. Nodes with the same
colours can thus transmit concurrently without any collision. GC-MAC also
does not require CDMA or power adjustment for collision resolution. Our
extensive simulation study reveals that our proposed protocol can efficiently
handle the traffic contention to achieve significant improvement in terms of
throughput, energy consumption, and fairness index under varying offered
loads.
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جوائز التكريم:
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الجائزة (1):
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مسمى الجائزة:
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The
award for the best poster in the department of Computing, Communications and
Interactive Systems
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الجهة المانحة:
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Glasgow Caledonian University
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تاريخ الجائزة:
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11/11/2015
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مجال التكريم:
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the best poster in the department of
Computing, Communications and Interactive Systems for project “Performance
Comparison of Sender-based and Receiver-based Scheduling in UWSN MAC
Protocols” at the School of Engineering and Built Environment Research
Colloquium
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