IEEE-32331
Route Maintenance in Set Routing using FLT for Mobile Wireless Sensor Networks M.S.Godwin Premi, U.Nivetha, Betty Martin, S.Maflin Shaby Faculty of Electrical and Electronics, Sathyabama University Chennai -119
[email protected] Abstract – The goal of wireless sensor networks is the maximum data gathering. Factors like energy, memory, bandwidth and processing capability affects the characteristics of the network which implies in reduced data collection. To avoid the reduction in data collection, mobile sensor nodes are used. They cover large area in short time and these networks are called as mobile wireless sensor networks (MWSN). In MWSN, set routing is used as one of the routing method for maximum data collection. In which the entire network is divided into many sets. This routing algorithm is applied for each set with the consideration that there is no node failure in the network. Here this work shows that how a new route is discovered if a node fails in a set using the Foldable Lookup Table (FLT) method. Also FLT method is compared with the routing table developed by fuzzy variables. Simulation is performed with OMNET++ simulator. Result shows the effectiveness of node failure in terms of delay and packet drops and how the route is maintained during node failure is shown with respect to delay. Keywords: mobile nodes, set routing, wireless sensor networks
I. INTRODUCTION Sensors placed in the structures, machinery, and the environment, joined with the efficient delivery of sensed information, could provide various benefits. Major advantages of these include: conservation of natural resources, enhanced manufacturing productivity, immediate emergency response, and improved homeland security. But due to the breakages occur in the connector which can be a lead wire or fiber optic cable, the overall quality of the network is reduced. To reduce the connection failures as well as the maintenance cost it would be best to select the wireless sensor network. Wireless sensor networks are started spreading in industries. The wireless sensor networks in industrial applications comes under the category of low rate - wireless private area networks (LRWPAN). The IEEE 802.15.4 defines the industrial standard for LR-WPAN[11]. Comparing to wireless local area network (WLAN) which is standardized under the category of IEEE 802.11, the LR-WPAN - IEEE 802.15.4 deals about low power, low energy, short range and low data rate. IEEE 802.15.4 defines the specifications of the physical layer and also about the Medium Access Control (MAC) layer. Zigbee is built on the standard in IEEE 802.15.4 which deals about the energy efficiency.
II. RELATED WORK Studies related to mobile sink node generally attempt to prolong the lifetime of the network. Due to the sink mobility, the sensor nodes in the network can take turns to become the neighbors of the sink so energy can be consumed evenly among the sensor nodes, and consequently the lifetime of the entire network can be prolonged. But during the mobility of sinks the network topology changes which gave an impact on routing. Thus reconstruction of routes is in need in this type of applications. The paper [3], [4],[5] proposes the local update method to update the new location of the sink with a single mobile sink. The energy consumption is compared with the flooding method. Simulating a sensor network found to be a problem and is solved by some of the authors with NS-2 or matlab. But significant amount of research results are coming out using omnet++ network simulator. Very few works addressed about the routing with mobility in WSN. In the previous work [1], [2] we presented about sink mobility and about the routing methods to increase the lifetime. The previous papers dealt about set routing technique for mobile nodes in a network. Here we present the effect of node failures with the set routing. III. SYSTEM DESCRIPTION The square shape of the sensor field is considered. The sensor nodes are deployed randomly in one end of the sensing field. Sink node is placed in the centre of the sensing field. All the nodes are grouped into sets. Set routing is the technique in which grouping is based on relative neighborhood with the base station or sink node. Each set is comprised of n2 nodes where ‘n’ can be 2, 3, 4 or above [1]. In any routing schemes two phases are considered where the first phase is the route discovery and the next phase is the route maintenance. In [1] first phase is discussed. Here we compared the new route maintenance method (FLT) with the fuzzy set route maintenance [2]. We proposed three scenarios by considering single node, double node and triple node failures in a set respectively. If a node fails in between a source sensor node and the destination sink node then it is necessary that the sensor node has to take a different route to deliver its message. For all the scenarios we considered the set with n=3 ie; nine nodes in a set.
In the first scenario, we considered that any one of the node in a set fails. In a nine node set there is a possibility of 27 cases Veltech Multitech Dr.Rangarajan Dr.Sakunthala Engineering College, within 3 hops distance considering at least one node in each Avadi, Chennai (Sponsors) hop. Here we considered either the case 1 or case 2 as the initial position. In case 1, one node is selected with single hop, 3 nodes are selected with 2 hops and 5 nodes are selected with 3 hops. In case 2, three nodes are selected with single hop, 3 International Conference on Science, Engineering and Management Research (ICSEMR 2014) 978-1-4799-7613-3/14/$31.00 ©2014 IEEE
IEEE-32331 nodes are selected with 2 hops and 3 nodes are selected with 3 hops. The directions of movement of sensor nodes are based on the rule below [1]: LEFT Æ LEFT Æ DOWN Æ DOWN Æ RIGHT Æ RIGHT Æ UP Æ UP s7
s8
s9
s7
s8
s9
s4
s5
s6
s4
s5
s6
s3
s2
s1
s3
s2
s1
BS (a)
BS (b)
Fig.3. Initial Position of a set (a) Case 1 (b) Case 2
Using this rule the eight directions are covered by the set nodes. (NW Æ N Æ NE Æ E Æ SE Æ S Æ SW Æ W). Each movement is performed twice before switching into other movement.Fig.3. (a) and (b) shows the initial position of a set with no failure case. Here s1 to s9 represents the sensor nodes and BS represents base station or sink node. For case 1, initial position is the Position I and Position II is nothing but case 2. All the eight positions are arrived with moving sensor nodes in a direction said above.
fig.4.(e), (f) and (h) show that there is also only one node failure but there are changes in the route. New route is created for only one node in each condition. For the condition shown in fig.4.(i) show that there is also only one node failure but the data delivery will be stopped until the other nodes reach the new position. This is because of the node failure nearest to the base station. From this it is inferred that if a node present in the last hop fails, it will not affect the existing routes. But if it happens for the middle then new route has to be created and has to be maintained. Also if a node present nearest to the sink or base station fails then the data cannot be forwarded by that node. From this Fig.5 it is understood that if a node present in the last hop fails, it will not affect the existing routes. But if it happens for the middle then new route has to be created and it has to be maintained. Also if a node present nearest to the sink or base station fails and an alternate route can be found with the nodes present in one hop. By this data monitoring or collection can be done continuously with the alternate routes. So the node failure will not interrupt in data collection because of the presence of alternate router nodes in single hop. In the second scenario, it is considered that any two of the nodes in a set fails. Two examples for this node failure is shown in Fig.5.
(a)
(b)
Fig.5. Examples of two nodes failure in Position I
In the third scenario, it is considered that any three of the nodes in a set fails. The proposed route maintenance using FLT follows the look up table method. But it overcomes the requirement of memory. Initially the routes are discovered by using set routing technique and are stored in the routing table. Later this table is changed as the foldable look up table based on the route requirement. Fig.6 shows the entire coverage of the set of all nodes in eight different positions. The tables shown below give the original routing tables and foldable lookup tables for each node in the set of nine nodes. I
II
VIII
Fig.4. All possibilities of single node failure in case 1 with Position I
Fig.4. shows the possibilities of single node failure in Position I. Fig.4. (a), (b), (c), (d) and (g) show the set with only one node failure. Node with a cross mark indicates the dead or failed node. In these conditions old routes are maintained with no message from the dead node. In the conditions shown in
VII
III
IV
VI
V
Fig.6. Entire coverage of 4-node Set with 8 positions
IEEE-32331
ORIGINAL ROUTING TABLES
FOLDABLE LOOKUP TABLES Node id s1
Node id s2
Node id s3
Node id s4
Node id s5
Position I II III IV V VI VII VIII Position I II III IV V VI VII VIII Position I II III IV V VI VII VIII
Position I II III IV V VI VII VIII
Position I II III IV V VI VII VIII
Hop count 1 1 3 3 3 3 3 1
Next hop node sink sink s2 s2 s5 s4 s4 sink
Hop count 2 1 2 2 3 3 3 2
Next hop node s1 sink s3 s3 s5 s5 s5 s1
Hop count 3 1 1 1 3 3 3 3
Next hop node s2 sink sink sink s6 s6 s5 s2
Hop count 2 2 3 3 3 2 2 1
Next hop node s1 s1 s5 s5 s5 s7 s7 sink
Hop count 2 2 2 2 2 2 2 2
Next hop node s1 s2 s3 s6 s9 s8 s7 s4
route s2-s3 s2-s3 s5-s9 s4-s7 s4-s7 -
Node id s1
Position
Node id s2
Position
I, II, VIII III, IV V VI, VII
Hop count 1 3 3 3
Next hop node sink s2 s5 s4
route s2-s3 s5-s9 s4-s7
route s1 s3 s3 s5-s9 s5-s8 s5-s7 s1
I,VIII II III, IV V VI VII
Hop count 2 1 2 3 3 3
Next hop node s1 sink s3 s5 s5 s5
Hop count 3 1 3 3
Next hop node s2 sink s6 s5
route s1 s3 s5-s9 s5-s8 s5-s7
route s2-s1 s6-s9 s6-s9 s5-s7 s2-s1
Node id s3
Position I, VIII II, III, IV V, VI VII
route s2-s1 s6-s9 s5-s7
route s1 s1 s5-s1 s5-s6 s5-s9 s7 s7 -
route s1 s2 s3 s6 s9 s8 s7 s4
Node id s4
Position
Node id s5
Position
I, II III IV V VI, VII VIII
I II III IV V VI VII VIII
Hop count 2 3 3 3 2 1
Hop count 2 2 2 2 2 2 2 2
Next hop node s1 s5 s5 s5 s7 sink
Next hop node s1 s2 s3 s6 s9 s8 s7 s4
route s1 s5-s1 s5-s6 s5-s9 s7 -
route s1 s2 s3 s6 s9 s8 s7 s4
IEEE-32331 ORIGINAL ROUTING TABLES Node id s6
Node id s7
Node id s8
Node id s9
Position I II III IV V VI VII VIII
Position I II III IV V VI VII VIII
Position I II III IV V VI VII VIII
Position I II III IV V VI VII VIII
Hop count 3 2 2 1 2 2 3 2
Next hop node s5 s3 s3 sink s9 s9 s5 s5
Hop count 3 3 3 3 3 1 1 1
Next hop node s5 s4 s3 s8 s8 sink sink sink
Hop count 3 3 3 2 3 1 2 2
Next hop node s5 s5 s3 s9 s8 sink s7 s7
Hop count 3 3 3 1 1 1 3 3
Next hop node s5 s6 s3 sink sink sink s5 s8
FOLDABLE LOOKUP TABLES route s5-s1 s3 s3 s9 s9 s5-s7 s5-s4
Node id s6
Position I II, III IV V, VI VII VIII
Hop count 3 2 1 2 3 3
Next hop node s5 s3 sink s9 s5 s5
Hop count 3 3 3 3 1
Next hop node s5 s4 s3 s8 sink
Hop count 3 3 3 2 3 1 2
Next hop node s5 s5 s3 s9 s8 sink s7
Hop count 3 3 3 1 3 3
Next hop node s5 s6 s3 sink s5 s8
route s5-s1 s3 s9 s5-s7 s5-s4
route s5-s1 s4-s1 s5-s3 s8-s9 s8-s9 -
route s5-s1 s5-s2 s5-s3 s9 s8-s9 s7 s7
Node id s7
Position I II III IV, V VI, VII, VIII
Node id s8
Position
Node id s9
Position
I II III IV V VI VII, VIII
route s5-s1 s4-s1 s5-s3 s8-s9 -
route s5-s1 s5-s2 s5-s3 s9 s8-s9 s7
route s5-s1 s6-s3 s5-s3 s5-s7 s8-s7
I II III IV, V, VI VII VIII
route s5-s1 s6-s3 s5-s3 s5-s7 s8-s7
IEEE-32331 In this FLT, if anyone node fails the alternate route is easily determined because the failed node is removed and the FLT is updated for all the nodes in the set. IV. CONDITIONS CONSIDERED The conditions considered for this wireless sensor network is to have homogenous nodes with mobile unit and directional sensor in each node. All sensor nodes are controlled by sink node in such a way that they are static and mobile alternatively with regular intervals. Moreover the initial locations of all the nodes are known by the sink node. In other words, the nodes move in a particular direction for a certain period and then static for a limited time. The direction of movement is fixed and is considered that during static condition the nodes can collect and transmit the data but during mobility the nodes can only collect the data. Using low cost localization algorithm the sink/base station knows the initial location of all the nodes. In set routing since the mobility pattern and velocity are fixed for all the nodes the new location can be determined by the sink node.
Based on the parameters simulations are carried out in OMNET++ network simulator. For case 1 and case 2, three scenarios are performed. Overall end to end delay is plotted in Fig.7 and the memory requirement is given in Fig.8. The output in Fig.9 shows the difference in packet drops for FLT and fuzzy based. Table.2. Channel Control Parameters
S.No.
Channel Control Parameters
Value
1. 2. 3. 4. 5.
Carrier Frequency pMax sat alpha Number of Channels
2.4GHz 2.0mW -85dBm 2 27
Table.3. Physical Layer Parameters
V. EVALUATION METRICS
S.No.
Physical Layer Parameters
Value
We used the same radio model as stated in [1] with Eelec=50nj/bit as the energy being dissipated to run the transmitter or receiver circuits and Eamp=100pJbit/m2 as the energy dissipation of the transmission amplifier. The energy cost of transmission and reception for common sensor nodes is calculated as shown below.
1. 2. 3. 4. 5. 6.
Channel Number Transmitter Power Sensitivity Path Loss Alpha Thermal Noise SNIR Threshold
10 1.0mW -85dBm 2 -110dBm 4dB
Table.4. Battery Parameters
with d as the length of the message in bits, d as the distance between transmitter and receiver node and Ȝ as the path- loss exponent. The energy spent for mobility calculated as,
where ‘F’ is the force in Newton, ‘v’ is the velocity in m/s and ‘t’ is the time taken in seconds. The energy spent for every new route establishment is given by where ‘n’ is the total number of nodes, ‘br’ is the total number of routing bits stored, ‘k’ is the Boltzmzn’s constant and ‘T’ is the temperature of the medium.
S.No.
Battery Parameters
Value
1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Battery Capacity Mean Time to Failure Battery Resolution Usage Cpu Active Usage Cpu Sleep SNIRThreshold Publish Time Usage Radio_idle Usage Radio_recv Usage Radio_sleep
25 mAh -1s 1s 7.6 mA 0.237 mA 4dB 20s 0.37mA 19.47mA 0.02mA
Mean End to End Delay 100
V. SIMULATION RESULTS
FLT Fuzzy
90 80
Table.1. Network Settings
S. No. 1. 2. 3. 4. 5. 6.
Network Settings
Value
Playground Size X Playground Size Y Number of hosts (sensor nodes) Sink Sink mobility Sensor node mobility
500 500 9 1 Null Linear
70 Mean delay, sec
Simulations for all the three scenarios are carried out based on IEEE802.15.4. The network settings, channel control, physical and battery parameters are given in Table.1, 2, 3 and 4 respectively.
60 50 40 30 20 10 0 10
20
30
40 50 60 Number of iterations
Fig. 7. Mean end to end delay
70
80
90
IEEE-32331 [8] Memory Requirement for Routing Table 5000 FLT Original routing table
4500
[9]
4000
[10]
Size,kb
3500 3000 2500
[11]
2000
[12]
1500 1000 500
1
2
3
4
5 Node
6
7
8
9
Fig. 8. Memory requirement Packet drops 80 FLT Fuzzy
75 70
dropped Packets
65 60 55 50 45 40 35 10
20
30
40 50 60 Number of iterations
70
80
90
Fig. 9. Packet Drops
VI. CONCLUSION From the simulation results it is seen that FLT route maintenance is better than fuzzy based route maintenance. Thus for a large sensor network, set routing can be used with FLT for maintenance in order to reduce the memory requirement, packet delay and drops.
REFERENCES [1] [2] [3] [4]
[5] [6] [7]
M.S.Godwin Premi, K.S.Shaji, “Set Routing for Mobile Wireless Sensor Networks”, Conference Proceedings of RTCSP, Mar.2011. Jamal Al-Karaki, Ahmed E.kamal, “Routing Techniques in Wireless Sensor Networks”, IEEE Wireless Communications. Dec.2004. Jun Luo, Jean–Pierre Hubaux, “Joint Mobility and Routing for lifetime Elongation in Wireless Sensor Networks”, IEEE INFOCOM, 2005. Guojan Wang, Tian Wang, et.al., “Local Update Routing Protocol in Wireless Sensor Networks with Mobile Sinks”, IEEE Communications Society, 200ee M.S.Godwin Premi, K.S.Shaji, “MMS Routing for Wireless Sensor Networks”, IEEE Computer Society, Feb.2010. A Novel Stateless Energy-Efficient Routing Algorithm for Large-Scale Wireless Sensor Networks with Multiple Sinks Karim Seada, Ahmed Helmy, “Efficient Geocasting over Perfect Delivery in Wireless Networks”, IEEE Communications Society, WCNC 2004.
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M.S.Godwin Premi, K.S.Shaji, “MMS Routing to Enhance Lifetime in Wireless Sensor Networks”, IEEE Conference Proceedings of Wireless Communication and Sensor Networks, Dec.2009. Lei Zhang, Z.Hu, Y.li, X.Tang, “Grouping based Clustering Routing Protocol in Wireless Sensor Networks”, IEEE Communications Society, 2007. O.Younis, S.Fahmy, “HEED: a hybrid, energy efficient distributed clustering approach for adhoc sensor networks”, IEEE Trans. Mobile computing, Oct.2004. Jun Liu, Xiaoyan Hong, “A Traffic-Aware Energy Efficient Routing Protocol for Wireless Sensor Networks”. M.S.Godwin Premi, K.S.Shaji, “Router Performance with AoI and RoI Routing in Wireless Sensor Networks”, IEEE Conference Proceedings of Communication Control and Computing technologies, Oct.2010. Feng Chen, Nan Wang, Reinhard German and Falko Dressler, “Simulation study of IEEE 802.15.4 LR-WPAN for industrial applications”, Wirel. Commun. Mob. Comput. 10: 609–621 (2010), Published online in Wiley InterScience.
