Smartening the Environment using Wireless Sensor Networks in a Developing Country Presenter Al-Sakib Khan Pathan Department of Computer Science International Islamic University Malaysia, Malaysia A TEST-BED ANALYSIS FOR SEAMLESS MIPV6 HANDOVER IN HETEROGENEOUS ENVIRONMENT Mohammad Moshee Uddin, International Islamic University Malaysia Al-Sakib Khan Pathan, International Islamic University Malaysia Shariq Haseeb, MIMOS Berhad, Kuala Lumpur, Malaysia Mohiuddin Ahmed, Jazan University, Saudi Arabia

Introduction Background Objective Experimental Setup Analysis and Results Concluding Remarks 2 ISCE, June 14-17, 2011, Singapore Outline of the Presentation

Use of multiple network interfaces is becoming more common with a mobile node (MN). Now-a-days, almost every hand-held device has multiple network interfaces built-in –Wi-Fi –Ethernet –WiMAX –Bluetooth –UMTS Multiple network interfaces converged network –Ubiquitous communications 3 Introduction ISCE, June 14-17, 2011, Singapore

Mobile IPv4 (MIPv4) has become a part of the solution for the mobility support system to have ubiquitous communication. Yet, it could not solve lots of problems because of its limitations to support wide-scale applications such as Peer-to-Peer (P2P) applications, addressing limitations as well as IPsec (Internet Protocol Security), etc. 4 Introduction (Continued) ISCE, June 14-17, 2011, Singapore

MIPv6 is a key protocol which allows a node to have ubiquitous communication with the help of mobility support system. It allows MN to change its point of attachment without changing the “Home Address” of MN. So any packet may still be routed regardless of any point of attachment as long as it is attached to the Internet. 5 Background: MIPv6 ISCE, June 14-17, 2011, Singapore

Furthermore, multiple network interfaces also can be handled by MIPv6 protocol to support heterogeneous mobility. For instance, the movement from one Wi-Fi segment to Ethernet segment or Ethernet segment to Wi-Fi or Wi-Fi segment to WiMAX, and so forth, if the “Home Address” remains the same. 6 MIPv6 (Continued) ISCE, June 14-17, 2011, Singapore

Test-bed experimentations of vertical MIPv6 handover performance (i.e., from Ethernet segment to Wi-Fi segment and vice versa) to evaluate –Handoff latencies –Packet losses while multiple interfaces are simultaneously associated with different types of networks. 7 Main Objective of the Work ISCE, June 14-17, 2011, Singapore

8 MIPv6 Handover Process ISCE, June 14-17, 2011, Singapore

The test-bed has been implemented with two scenarios: –Scenario1: When MN moves around between home link and foreign link (Figure 1) –Scenario 2: Again when MN moves around foreign links (Figure 2) 9 Our Experimental Setup ISCE, June 14-17, 2011, Singapore

10 Scenario 1 (Figure 1) Two PC-based routers: HA and FR One switch One IEEE abg Access Point One notebook as MN with one Ethernet and one wireless interface built-in One PC-based Correspondent Node (CN). ISCE, June 14-17, 2011, Singapore

11 Scenario 2 (Figure 2) Three PC-based routers: HA, FR1, and FR2 Two switches One IEEE abg Access Point One notebook as MN with one Ethernet and wireless interface built-in One PC-based CN ISCE, June 14-17, 2011, Singapore

Figure 1 shows MN is associated with HL via Ethernet & at the same time Wi-Fi network coverage is present. At this moment, MN is communicating with CN via home link. Since Wi-Fi network is available, MN is also pre- associated with Wi-Fi network (a.k.a FR). 12 Experiment Methodology ISCE, June 14-17, 2011, Singapore

At any given time, to create a vertical handover, Ethernet connection has been disconnected manually from the home link. Then the Wi-Fi interface immediately takes over the data communication from Ethernet. This type of vertical handover has happened from home network to foreign network. 13 Experiment Methodology (Contd.) ISCE, June 14-17, 2011, Singapore

Likewise, while MN is associated with the Wi-Fi network and communicates with CN, at any given time Ethernet cable has been manually plugged into the MN. After that, Wi-Fi interface has been disconnected from foreign link and Ethernet immediately takes over the handover procedure. The packets are captured to determine handoff delays and packet losses while MN moves from home link to foreign link and vice versa with multi-homed MN. 14 Experiment Methodology (Contd.) ISCE, June 14-17, 2011, Singapore

In a similar fashion, handoff delays and packet losses have been captured (see Figure 2), while MN moves from foreign link to a new foreign link using multiple network interfaces. 15 Experiment Methodology (Contd.) ISCE, June 14-17, 2011, Singapore

The handover measurement has been conducted 50 times with the multi-homed MN between 2 and 3 seconds interval of router advertisement. MIPv6 tester [1] tool has been used to capture the heterogeneous handoff latency where it opens bi- directional TCP/UDP packets between MN and CN over the network. To capture packet loss, ‘iperf’ [2] tool has been used during heterogeneous handover. 16 Methodology and Tools ISCE, June 14-17, 2011, Singapore

List of Notations 17 Mathematical Analysis L Total Total handover latency L2L2 Total layer 2 handover latency L3L3 Total layer 3 handover latency L Probe Layer 2 latency that scans for available AP L Auth Layer 2 latency that performs authentication L Re-assoc Layer 2 latency that performs re-association L Router Discovery Layer 3 latency that performs IP address configuration L DAD Layer 3 latency that performs uniqueness on the link L BU Layer 3 latency that performs a message regarding location status L BA Layer 3 latency that performs a message confirming location status ISCE, June 14-17, 2011, Singapore

According to [3], [4], [5], and [6], total handover latency in MIPv6 could be mathematically put as follows: Therefore, L Total = L Probe + L Ahth + L Re-assoc + L Router Discovery + L DAD + L BU + L BA (4) 18 Mathematical Analysis L Total = (L 2 + L 3 )(1) L 2 = L Probe + L Auth + L Re-assoc (2) L 3 = L Router Discovery + L DAD + L BU + L BA (3) ISCE, June 14-17, 2011, Singapore

This total handover latency (equation 4) is calculated once the current AP becomes unavailable and MN associates itself with a new AP during the movement (i.e. a scenario of horizontal handover). –Suppose an MN is associated with network X, at the same time it could be under the coverage of network Y. Therefore, it can pre- associate with the network Y while network X is still available. But at any time network X may no longer available, then the communication with MN will be handed over to network Y (X and Y could be any type of network such as Ethernet LAN, Wi-Fi network, WiMAX network, UMTS etc). 19 Analysis ISCE, June 14-17, 2011, Singapore

TABLE 1. HANDOFF LATENCY DURING THE MOVEMENT OF MN 20 Results: Handoff Latency HN to FN (Sec)FN to FN (Sec)FN to HN (Sec) Max Min Average Figure 3 ISCE, June 14-17, 2011, Singapore

While MN is handed over to FN from HN with multi- homed interfaces, the average delay is 1.835s (Table 1), whereas the average handover delay with single interface is 3.677s as in [7] and 3.447s as in [8]. As for single interface handover process, it has to maintain total layer 2 and layer 3 procedures following equation 4. But for multi-homed MN, if one of the interfaces is pre- associated with foreign network; layer 2 handover delay can be reduced from total delay. Therefore, we can get from the equation 1, L Total = (L2 + L3) - L2 = L3 21 Results Analysis ISCE, June 14-17, 2011, Singapore

Observing this experiment, multi-homed MN also reduces the processing time of layer 3 (router discovery and DAD [Duplicate Address Detection]) except binding update (BU) and binding acknowledgement (BA). 22 Results Analysis ISCE, June 14-17, 2011, Singapore

On the other hand, while MN handover is done from FN to another FN or it returns to home network from any foreign network (Figure 3 and Table 1), minimal handover latency occurs that could not be possible to be detected by the MIPv6 tester tool. As multi-homed MN is simultaneously associated with the networks, only one of the interfaces would be communicating but HA keeps tracking all interfaces. This immediate handover procedure time is approximately unnoticeable. So from these experiments and equation number 1, it can be derived, L Total ≈ 0, if multi-homed MN is pre-associated. 23 Results Analysis ISCE, June 14-17, 2011, Singapore

TABLE 2. PACKET LOSS DURING THE MOVEMENT OF MN 24 Results: Packet Loss HN to FN (Sec)FN to FN (Sec)FN to HN (Sec) Max Min Average Figure 4 ISCE, June 14-17, 2011, Singapore

Figure 4 shows the total packet loss in percentages of 50 trials during handoff and Table 2 summarizes maximum, minimum and average packet loss. With multi-homed MN, average packet loss is about 3.85% while it moves from home network to foreign network. At this point, packet loss occurs during binding update and binding acknowledgement processes at layer 3 as in handoff latency. Packet loss is proportional to handoff latency. L Total ∝ P Total (where P Total is total packet loss) 25 Results: Packet Loss ISCE, June 14-17, 2011, Singapore

Again, while multi-homed MN moves from one foreign network to another or returns to home network, minimal packet loss may occur that also could not be detected, similar to the handoff latency. Therefore, packet loss is approximately unnoticeable as shown in Figure 4 and Table 2 during the MN’s movement from foreign network to another or its return to Home network. Hence, P Total ≈ 0%, if multi-homed MN is pre-associated. 26 Results: Packet Loss ISCE, June 14-17, 2011, Singapore

MIPL (Mobile IPv6 for Linux) enables all the features of mobility for heterogeneous environment, yet some delays may occur during handover processes which cause some major packet loss. There are handoff delays and packet losses during the handover process from HN to FN which degrade the performance of communication. While MN moves from one FN to another or returns to home network, handoff delay and packet loss are almost unnoticeable and this improves communication process. 27 Concluding Remarks ISCE, June 14-17, 2011, Singapore

Based on our findings we may state that; with the help of MIPv6, a multi-homed MN may perform better vertical handover process while it moves among foreign networks in heterogeneous environment. As our future work, we would like to perform an extended experiment and analyze other associated parameters to get a detailed understanding of the potential use of the technology for consumer related applications as well as for other application areas. 28 Concluding Remarks ISCE, June 14-17, 2011, Singapore

[1] MIPv6 tester, retrieved June 1 st, 2010 from [2] Measure Network Performance with iperf, Retrieved June 1 st,2010,from [3]D. Johnson, C. Perkins and J. Arkko, “RFC 3775 Mobility Support in IPv6,” URL reference: (June 2004). [4]M. Siksik, H. Alnuweiri and S. Zahir, “A Detailed Characterization of the Handover Process Using Mobile IPv6 in Networks,” IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, Victoria, Canada, August [5]V. Vassiliou and Z. Zinonos, “An Analysis of the Handover Latency Components in Mobile IPv6,” Journal of Internet Engineering, Vol.3, No.1, December, 2009, pp [6] S. Haseeb and G. Kurup, “Performance Analysis of MIPL based Mobile IPv6 Testbed,” Proceedings of the 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, May 14-17, 2007, Penang, Malaysia. 29 Major References ISCE, June 14-17, 2011, Singapore

[7] V. Vassiliou and Z. Zinonos, “An Analysis of the Handover Latency Components in Mobile IPv6,” Journal of Internet Engineering, Vol.3, No.1, December, 2009, pp [8] S. Haseeb and G. Kurup, “Performance Analysis of MIPL based Mobile IPv6 Testbed,” Proceedings of the 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, May 14-17, 2007, Penang Malaysia. 30 Major References ISCE, June 14-17, 2011, Singapore

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