Simulation and evaluation about mac protocols in wireless sensor network using NS2

ckets to the medium, it 
first call clear channel assessment (CCA) procedure 
to sense the medium for activity. If the medium is 
idle for at least a inter-frame space time (DIFS), the 
node can transmit packets. Otherwise, the node runs 
a back-off algorithm to delay transmission to a later 
time. The binary exponential back-off algorithm 
will randomly select a number of time slots to wait 
and store this value for a back-off counter for later 
time.
IEEE 802.11 was designed for one hop links 
in network; it provides efficiently services networks 
due to its basic characteristics as high bit rates, 
simple to implement, flexibility in architecture and 
a cost effective method for channel allocation, but 
due to the fact that it is not sleep period strategy and 
consumes more energy in long idle listening, thus it 
is not suitable for WSN.
B. IEEE 802.15.4
IEEE 802.15.4 standard is designed for 
low-rate and low-power applications [11]. In 
physical layer, it can work at three operational 
frequency bands: 868 MHz, 915 MHz, and 2.4 
GHz bands. There are 27 sub-channels defined 
in IEEE 802.15.4 standard, which consists of 16 
sub-channels in 2.4 GHz band, 10 sub-channels 
in 915 MHz band and one sub-channel in the 868 
MHz band. IEEE 802.15.4 standard can operate 
in two modes: a beacon-enabled mode and non-
beacon enabled mode. In a non-beacon enabled 
mode, IEEE 802.15.4 uses un-slotted CSMA/CA 
algorithm to control medium access and maintain 
network activities. In a beacon-enabled mode, 
the network is managed by a coordinator device, 
which regularly transmits a beacon frame to other 
devices to synchronize and identify network. The 
beacon-enabled mode of IEEE 802.15.4 consists 
of a contention access period (CAP), a contention 
free period (CFP) and inactive period that is in a 
super-frame. The super-frame structure is shown as 
Figure 1 follows:
Fig. 1. Superframe structure of IEEE 802.15.4
ISSN 2354-0575
Khoa học & Công nghệ - Số 23/Tháng 9 - 2019 Journal of Science and Technology 41
where aBaseSuperframeDuration = 960 symbols, 1 
symbol = 16 µs, BO is Beacon Order, and SO is 
Superframe Order. The coordinator communicates 
with other nodes during the active period and sleeps 
during the inactive period. In a beacon-enabled 
mode, the nodes use a slotted CSMA/CA protocol 
in the CAP period to transmit data packets to other 
nodes. To save energy, all the nodes will go into a 
sleep period during the long inactive period.
C. Sensor-MAC (S-MAC)
S-MAC [2, 7] is a medium access control 
protocol base on contention-based random access 
that allows nodes directly communicate to each 
other in network. S-MAC is designed to reduce 
energy consumption from all the sources for 
wireless sensor networks that we can identify 
to cause energy waste (collision, idle listening, 
overhearing and control overhead) by using fixed 
listen and sleep duty cycle called a time frame, in 
which nodes periodically transition between a listen 
state and a sleep state to reduce energy consumption 
in idle listening channel.
A time frame in S-MAC contains two parts: 
one for a listening period and the other for a sleeping 
period as shown in Figure 2 follow:
Fig. 2. Listen and sleep period of S-MAC
During a listen period, the nodes communicate 
with other nodes by exchanging SYNC, Request-
To-Send (RTS), and Clear-To-Send (CTS) messages 
before transmitting data packets. In sleep period, 
the nodes will turn off radio fully to save energy 
and wake up at a scheduled time in a next frame. If 
a node has data to send in this period, it must defer 
its transmission until the next listen period.
In order to synchronize the time of listen and 
sleep period among nodes in network, the nodes 
regularly share their information about schedule 
table by broadcasting SYNC message, which is 
very small and consist of node ID (identification), 
the next sleep time... 
In network, a packet collision occurs when 
two or more nodes attempt to transmit packets into 
the medium over the network at the same time. 
Packet collisions can be the cause of wasting energy 
and decreasing performance network. To solve this 
problem, S-MAC uses traditional mechanisms like 
the IEEE 802.11 such as the exchange of RTS/CTS 
message and using ACK message to affirm a good 
data packet received. In addition, S-MAC combines 
the physical carrier sensing called Clear Channel 
Assessment (CCA) and virtual carrier sensing 
called Network Allocation Vector (NAV) to avoid 
collision and overhearing. NAV contains a value, 
only when this value is set to zero, packets can be 
transmitted.
D. Simulation Parameters
To evaluate the performance of IEEE 802.11, 
802.15.4 MAC and S-MAC protocols, we use 
the network simulator ns-2 (v.2.35) [10] with the 
parameters in the scenarios that are described in 
Table I, [6, 7, 12].
Table I. The Arrangement of Channels
Parameters Values
Topology area 500 m × 500 m
Numbers of nodes 50
Antenna type Omni Antenna
Routing protocol AODV
Packet size 128 bytes
Simulation time 500 seconds
Transmission range (m) 250
Traffic type CBR
Data rate 1 (kbps)
Initial energy 2 (Joules)
Idle power 712e-6 (Watt)
Receiving power 0.3 (Watt)
Transmission power 0.6 (Watt)
Sleep power 144e-9 (Watt)
E. Performance Metrics
1) Energy Consumption
Energy consumption denotes the relationship 
among energy dissipation to the total of data packets 
delivered by each node in the network. A node 
consists of energy consumption in different states 
as transmission (E
Tx
), reception (E
Rx
), idle listening 
(E
Idle
), sleeping (ESlep), transition (Etrans) and CCA 
(E
CCA
) state that can be calculated as follows:
ISSN 2354-0575
Journal of Science and Technology42 Khoa học & Công nghệ - Số 23/Tháng 9 - 2019
/ /
( )
E E E E E E E
P Ps R P Ps R P T P T
P T k P T
node Tx Rx Idle Sleep Trans CCA
Tx i
i
Ntx
Rx j
j
Nrx
Idle Idle Sleep Sleep
trans trans
k
N
CCA CCA
1 1
1
trans
= + + + + +
= + + +
+ +
= =
=
/ /
/
(1)
where E
x
, P
x
 and T
x
 are the energy consumption 
(joules), the power (watt) and the time interval of 
transceiver in state x (second). Psi and R are the size 
of length of the ith packet of receiving or sending 
and R is the data transferring rate. N
tx
 and N
rx
 are 
total numbers of receiving or sending packets.
( )
E n
E i
AN
node
i
n
1= =
/
 (2)
where E
AN
 are the average energy consumption of all 
nodes in network, n is number of nodes in network.
2) Throughput:
Throughput express the total count of data 
packets transported to destination nodes of one flow 
(connection) in network during the simulation time. 
The average throughput of the entire 
network expresses the average throughput of 
each connection. The average throughput of each 
connection is calculated by the total size of received 
packets at destination node per the time, which 
takes for traffic to flow through the connection.
*
( )t t
Ps
bps
8
Throughput_of_ flow 
i
i
m
2 1
1
j = -
=
/
 (3)
)_ _ _ _ networkThroughput of (Throughput of flow j
j 1
k
=
=
/
(4)
where Psi is the size of length of the i
th packet 
reaching the destination, t
1
 and t
2
 are the time 
when first packet sent by source node and the time 
when last packets received by destination node, 
respectively.
3) Energy Efficiency:
Energy efficiency is defined as the throughput 
achieved per unit of energy consumed, where the 
throughput represents the number of successfully 
delivered packets.
_
_ ( )
( )
Energy efficiency
Energy consumption Joules
Throughput packets
= 
(5)
4) Packet Delivery Ratio (PDR):
PDR represents the ratio of data packets 
successfully received from all the sent data packets, 
which is computed as below:
PDR Ns
Nr= (6)
Where Nr and Ns are the number of packets received 
by destination node and the number of packet sent 
by source node, respectively.
III. Results and Analysis
Figure 3 represents the percentage of power 
consumption of IEEE 802.15.4, 802.11 MAC and 
S-MAC protocols during simulation time. It is 
clearly observable that the S-MAC protocol with 
active and sleep cycle has better performance in 
reducing energy consumption of nodes than IEEE 
802.15.4 and 802.11 MAC protocols.
Fig. 3. Energy consumption during the simulation 
time
Fig. 4. Energy consumption per number of flows
Figure 4 shows the energy consumption of 
nodes when we increase the number of connection 
ISSN 2354-0575
Khoa học & Công nghệ - Số 23/Tháng 9 - 2019 Journal of Science and Technology 43
(flow) in network. It seems that energy consumed 
increases as the number of nodes sent data packets 
increases with all MAC protocols, but it is rapid 
increase about energy consumption with IEEE 
802.11 MAC and S-MAC having the lowest 
consumption of energy.
As illustrated in Figure 5 and 6, the average 
throughput and energy efficiency of protocols 
is analyzed in increased number of sent nodes. 
We can see that IEEE 802.11 MAC with the high 
throughput achieved the better energy efficiency 
than IEEE 802.15.4 MAC and S-MAC protocols. 
Fig. 5. The average throughput
Fig. 6. Energy efficiency
In Figure 7, we illustrate the packet delivery 
ratio for both three protocols in the number of 
flows. Based on results shown in Figure 6, we can 
obviously observe that the packet delivery ratio in 
the network in the IEEE 802.11 MAC protocol is 
higher than about 200% compared to IEEE 802.15.4 
MAC and S-MAC protocols.
Fig. 7. Packet delivery ratio
The percentage of energy consumption 
in different states of all nodes in network are 
illustrated in Figures 8, 9 and 10 in which idle 
listening state consumes more energy than other 
states, it is 87.7%, 59 and 59% with IEEE 802.11, 
% IEEE 802.15.4 MAC and S-MAC, respectively. 
The sleeping and transition state consume lowest 
energy but the total of energy consumption of IEEE 
802.11 and 802.15.4 MAC protocols are still more 
higher than S-MAC because nodes have listened 
channel to check packets came while S-MAC 
achieves energy efficiency by switching the radio 
in sleep and active state periodically, so S-MAC 
achieves energy savings thereby providing longer 
lifetime of network. 
Fig. 8. Energy consumption in several states with 
IEEE 802.11 MAC
ISSN 2354-0575
Journal of Science and Technology44 Khoa học & Công nghệ - Số 23/Tháng 9 - 2019
Fig. 9. Energy consumption in several states with 
S-MAC
Fig. 10. Energy consumption in several states with 
IEEE 802.15.4 MAC
IV. Conclusion
In this paper, we analyzed the energy 
consumption of nodes in wireless sensor network 
considering the interactions of the IEEE 802.11, 
802.15.4 MAC and S-MAC protocols. Our goal is 
to evaluate performance of MAC protocols which 
helps the development of power saving schemes in 
WSN. Our simulation results show that the energy 
consumption of S-MAC with active and sleep cycle 
is better than that of IEEE 802.15.4 and IEEE 802.11 
MAC protocols about 10% case of large network 
(50 nodes deployed in 500m×500m area). Besides 
IEEE 802.11 consumes more energy but it has the 
packet delivery ratio is the most in MAC protocols.
References
[1]. A. Bengheni, F. Didi and I. Bambrik, “Energy-Saving Comparison of Asynchronous MAC 
Protocols for Wireless Sensor Networks,” International Conference on Mathematics and information 
Technology, December 2017, pp. 263-268.
[2]. C. Wang, Y. Chen and Y. Hou, “The analysis and improvement of SMAC protocol for Wireless 
sensor networks,” IEEE 9th International Conference on Mobile Ad-hoc and Sensor Networks, 
December 2013, pp. 437-441.
[3]. D. Simaiya, U. Sharma and A. N. Tripathi, “Simulation and Performance Evaluation of Energy 
Efficient MAC Protocols for Wireless Sensor Networks,” Tenth International Conference on Wireless 
and Optical Communications Networks (WOCN), July 2013, pp. 1-5.
[4]. H. Kobayashi, S. Izumi and K. Takahashi, “Proposal of IEEE 802.11 Wake-Up Control Method 
Using IEEE 802.15.4 for Low Energy Consumption,” the 5th International Conference on Business 
and Industrial Research (ICBIR), May 2018, pp. 17-20.
[5]. H. Xiao, D. M. Ibrahim and B. Christianson, “Energy Consumption in Mobile Ad Hoc Networks,” 
IEEE Wireless Communications and Networking Conference (WCNC), April 2014, pp. 2599-2604.
[6]. H. Y. Zhou, D. Y. Lou, Y. Gao and D. C. Zou, “Modeling of Node Energy Consumption for 
Wireless Sensor Networks,” Wireless Sensor Network, January 2011, vol. 3, pp. 18-23. 
[7]. M. Errouidi, H. Moudni, H. Mouncif and A. Merbouha, “An Energy Consumption Evaluation 
of Reactive and Proactive Routing Protocols in Mobile Ad-hoc Network,” the 13th International 
Conference Computer Graphics, Imaging and Visualization, March 2016, pp. 437-441.
ISSN 2354-0575
Khoa học & Công nghệ - Số 23/Tháng 9 - 2019 Journal of Science and Technology 45
[8]. R. Munadi, A. E. Sulistyorini, F. U. Fauzi and T. Adiprabowo, “Simulation and Analysis of Energy 
Consumption for S-MAC and T-MAC Protocols on Wireless Sensor Network,” IEEE Asia Pacific 
Conference on Wireless and Mobile, August 2015, pp.142-146. 
[9]. S. V. Rao and S. S. Pillai, “Performance of Sensor-MAC in an Energy Harvesting Environment,” 
Proceedings of IEEE International Conference on Circuits and Systems, December 2017, pp. 157-
161.
[10]. VINT Project, “The network simulator - NS2,”  (accessed: Sep 5, 
2019), 1997. 
[11]. W. Dargie and C. Poellabauer, Fundamentals of Wireless Sensor Networks Theory and Practice, 
USA: John Wiley & Sons, 2010, ch. 6, pp. 125-161.
[12]. Y. K. Huang, S. W. Huang and A. C. Pang, “An Energy-Efficient MAC Design for IEEE 
802.15.4-Based Wireless Sensor Networks,” IFIP International Federation for Information 
Processing, 2007, pp. 237-248.
MÔ PHỎNG VÀ ĐÁNH GIÁ CÁC GIAO THỨC TRUY NHẬP MÔI TRƯỜNG TRUYỀN
TRONG MẠNG CẢM BIẾN KHÔNG DÂY SỬ DỤNG NS2
Tóm tắt:
Một trong những thách thức của mạng cảm biến không dây là làm sao sử dụng hiệu quả nguồn năng 
lượng pin quý hiếm nhằm kéo dài thời gian sống của toàn bộ mạng vì các nút mạng sau khi sử dụng hết 
nguồn pin, chúng sẽ chết. Nhiều giao thức điều khiển truy cập môi trường truyền đã được đề xuất nhằm 
giảm năng lượng tiêu thụ của các nút cảm biến như chuẩn IEEE 802.11, 802.15.4 và giao thức S-MAC. 
Trong bài báo này, chúng tôi cung cấp đánh giá quá trình tiêu thụ năng lượng, thông lượng và sự chuyển 
phát gói tin của chuẩn IEEE 802.11, 802.15.4 và giao thức S-MAC. Các kết quả mô phỏng của chúng tôi 
cho biết rằng giao thức S-MAC với các chu kỳ hoạt động - ngủ tiêu thụ năng lượng ít hơn khoảng 10% khi 
so sánh với chuẩn IEEE 802.15.4 và ít hơn khoảng 15% khi so sánh với chuẩn IEEE 802.11.
Từ khóa: Mạng cảm biến không dây, hiệu quả năng lượng, S-MAC, IEEE 802.15.4, IEEE 802.11.