Performance Evaluation of Wireless n Using Level 2 and Level 3 Mobility

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1 Indian Journal of Science and Technology, Vol 11(14), DOI: /ijst/2018/v11i14/120616, April 2018 ISSN (Print) : ISSN (Online) : Performance Evaluation of Wireless n Using Level 2 and Level 3 Mobility Hind Sounni*, Najib Elkamoun and Fatima Lakrami Department of Physics, STIC Laboratory, Chouaib Doukkali University, El Jadida 24000, Morocco; hind.sounni@gmail.com, elkamoun@gmail.com, fatima.lakrami@gmail.com Abstract Objectives: To present a performance evaluation of a WI-FI network under the impact of mobility. It alsomakes the study and the evaluation cover for level 2 and level 3 mobility. Methods/Statistical Analysis: The OPNET simulator was used for simulating the scenarios of proposed architectures. For performance evaluations, the different parameter has considered, such as mobility speed, number of connected users and channel access methods. Findings: The main interest of this paper is to reveal the mobility schema that ensures a better continuity of providing services to mobile users moving between different Wi-Fi access points while considering a number of constraints related to the quality of service. Application/Improvements: Deploying level 2 roaming gives better results compared with level three roaming using MIPv4, while increasing the speed of mobility and the number of clients. Keywords: Level 2 Mobility, Level 3 Mobility, Performance Evaluation, MIPv4, n 1. Introduction The number of wireless devices for voice or data exceeds the number of fixed devices. Mobile data communication will likely emerge as the technology supporting most communication types including voice and video. Mobile data communication is present in cellular systems such as 3G and in wireless LAN such as and will extend into satellite communication. Wireless fidelity or Wi-Fi is one of the most used types that makes connection costs for large networks easier, cheaper, and allows wide coverage while assuring the QoS requested by users using multimedia applications. Though mobility may be enabling link-layer technologies, data crossing networks or different link layers is still a problem. The solution to this problem is a standards-based protocol, Mobile IP. This paper provides an overview of level 2 and level 3 mobil- ity using Mobile IPv4 technology by bringing different application schemes that can be used in a network. The rest of the paper has organized as follow: section 2 gives a description of wireless network parameters. Section 3 describes the mobility in a wireless network. The performance evaluation is presented by section 4. Section 5 resumes simulation results, while section 5 concludes the paper. 2. Wireless Network Parameters In wireless networks, several parameters are configurable and have a huge impact on wireless network performance (Wi-Fi), such us: 1. Access point properties: Antenna Gain, Modulation, Wireless Card, Standard, and Frequency, Transmit Power and Coverage, *Author for correspondence

2 Performance Evaluation of Wireless n Using Level 2 and Level 3 Mobility 2. Number of users: Channel access competition, 3. Mobility of users: Specifies whether the mobile node should switch to access points with higher signal strength either by using the level 2 mobility, and level 3 mobility, 4. Load: Based on the number of packets in network, and 5. Type of traffic: Best effort or Multimedia. This paper is particularly interested about studying the impact of two factors: mobility in term of speedand the number of users. 3. Mobility in Wireless Network There are several levels of mobility referring to the OSI model. The lowest level of mobility is level 2, which corresponds to the link layer of the OSI model. This level of mobility has known as Micro-mobility. The talking is about data-link (L2) roaming when a terminal re-associates with a new AP from the current AP within the same subnet 1 (APs belonging to the same subnet) Figure 1. The roaming includes a movement; it is quite conceivable to imagine during a movement to end up on another IP network than the original one. If the terminal connects to an AP in a different subnet, then network (L3) roaming will happen. This level of mobility has known as Macromobility Figure 1. Actually, Network roaming (L3) can occur only after a successful L2 roaming 1, Mobility Micro-mobility is the movement of a mobile node between two attachment points on the same network 2. The basic features of a mobility management are mainly the management of the location and management of handovers. For that, some functions must necessarily have a protocol authorizing the mobility management, citing the transfer of the packets, the update of the ways or the roads, the management of the handovers, the support of the inactive mobiles, the management of the addresses, the authentication and security mechanisms, etc. The criteria for selection of a mobility management protocol are mainly the total duration of the relay and packet loss rate during the procedure. This called Smooth Handover to designate a relay with a minimum of delay. Figure 1. Layer 2 and layer 3 roaming. 2 Indian Journal of Science and Technology

3 Hind Sounni, Najib Elkamoun and Fatima Lakrami 3.2 Macro-Mobility Macro-mobility is about moving between two different domains (networks). It can take place during an active session of a mobile user, or during a new session initiated by the user in a visited network. Mobile IP has designed to handle this type of mobility Mobile IP Overview Traditional IP technology cannot support mobility in IP layer.when a mobile node moves and attaches itself to another network; it needs to obtain a new IP addressthe reason why IETF defines Mobile IP 3. The fundamental assumption behind the development of Mobile IP was backward compatibility with the existing Internet infrastructure based on TCP/IP protocol suite originally developed for fixed networks 4. Figure 2 describes the functioning of mobile IP network. Different entities used in mobile IP networkare: MN: (Mobile Node) is a node that shows mobility without changing its IP i.e. it can change its point of attachment from one link to another but will be reachable through its home address, HA: (Home Agent) is a router on the HN that provides services to MN, FA: (Foreign Agent) is a router on the FN, and CN: (Correspondent Node) is a node that has intended to communicate with a MN. It may be mobile or a stationary node 5. Mobile IP uses the technique of re-routing to allow mobile nodes to roam around wireless LANs without disrupting transport sessions 6. By designating a Home Agent or HA on the mobile home network which must intercept the packets intended for the mobile and then encapsulate them to be sent to the foreign agent FA located in the visited network that intercepts packets destined for MN within the FN, encapsulates them and finally delivers them to the MN 7. When MN is on its home subnet, it uses normal IP protocol to communicate. While it enters the foreign subnet, it acquires an IP address, Called Care Of Address (COA). It then sends a registration message to HA to inform HA of its current location, COA8. When a correspondent CN decide to rejoin the mobile node, and it sent a datagram, which reaches the home network via standard IP routing. The datagram is intercepted by home agent HA and is tunneled to the care-of address, then delivered to the MN. Each time the mobile node enters a new network, a handoff triggers. The mobile gets a new temporary COA Figure 2. Mobile IP network. Indian Journal of Science and Technology 3

4 Performance Evaluation of Wireless n Using Level 2 and Level 3 Mobility address and registers it to HA again in order to be able to forward the datagram to it. When the MN leaves the old foreign network the mobile node sends registration request message to it s HA, indicating the change of its position and inform the HA to stop sending datagrams to the old FA that will be deleted Performance Evaluation The university has different departments scattered on a different position, Figure 3 it plans to install a Wi-Fi connection to cover the territory of its six departments IP network planning is proving necessary. The choice is either to put all the departments in the same IP network (Level 2 mobility) or to put each department in a network is separately or this case is mobility Level 3 (IP layer). The purpose of this work is to plan the wireless network in such manner to ensure a continuity of service with better QoS of mobile users even when moving from one network to another. The objective of this work is to give a comparative study between level 2-3 mobility in this experimental setting and to choose the appropriate access mode for the transfer of multimedia applications within the university taking into account several parameters that are mention in section 2. OPNET 17.5 is used to evaluate the performance of the proposed network, which makes it possible to build simulations of network infrastructure. In this simulation, the access points use n standard 9 (Data Rate 54 Mbps). Various scenarios are simulating based on different access methods: Distributed Coordination Function (DCF) and Enhanced Distributed Coordination (EDCF) 10, while varying different network parameters: mobility speed, and a number of users. Two types of traffic had been considered: data (best effort), and video (Multimedia). The simulation result is given just for multimedia traffic being the most sensitive for network variation. Different scenarios are generated by varying the number of clients (1,5, and 10) depending on mobility speed (1m/s, 5m/s, 10m/s). In each Mobile IPv4 scenarios, a comparison between access methods DCF and EDCF is done (the values used are by default). 5. Results 5.1 Level 2 and Level 3 Mobility Comparison Results give in terms of End to end delay that is defined as the time to transmit a packet across a network from source to destination. Figure 4-5 shows that in the case Figure 3. University departments. Figure 4. Mobile IP packet end-to-end delay. 4 Indian Journal of Science and Technology

5 Hind Sounni, Najib Elkamoun and Fatima Lakrami Figure 5. Level 2 mobility packet end-to-end delay. Figure 7. Level 2 mobility loss rate. Figure 6. Mobile IP loss rate. Figure 8. Mobile IP throughput. of level 2 mobility, better results are obtained than the case when L3 mobility has occurred.in fact, when there is macro mobility, a triangular routing increases the delay of packet transmission.in both cases of mobility (MIPv4 and mobility level 2), if the mobility speed increases the end to delay decreases. Packet loss occurs when one or more packets of data traveling across a network fail to reach their destination. Packet loss is typically caused by network congestion. It has measured the percentage of received packets compared to packets sent. As shown in Figure 6-7 loss rate in L 2, mobility is lower than loss rate obtained in the case of mobile IPv4. If the mobility speed increases, the loss rate decreases in the case of the MIP and increases in the case of the mobility level 2. Throughput represents the average number of bits successfully received or transmitted by the receiver per Indian Journal of Science and Technology 5

6 Performance Evaluation of Wireless n Using Level 2 and Level 3 Mobility Figure 9. Level 2 mobility throughput. Figure 11. DCF vs EDCF loss rate. unit time. Figure 8-9 shows a higher throughput for mobility Level 2 than mobility Level 3, and it decreases in both cases if the speed of mobility increases. 5.2 DCF and EDCF Comparison in Mobile IPv4 The EDCF delay gives better results compared to the DCF for the different scenarios that have been simulated (Figure 10). The results of DCF and EDCF loss rate in the case of 1m / s and 5m / s for different client numbers are almost the same. In the case of 10 m /s, the rate of loss of EDCF is very low compare to DCF (Figure 11). This comparison confirms the fact that EDCF gives better results compared to DCF in the case of level 2 and level 3 mobility using MIPv4 for multimedia traffic, because it privileges the transmission of sensitive traffics. 6. Conclusion In this paper, an experiment comparison between different types of mobility is given. The present study ensures a continuity of services to mobile users with a better quality of service in Wi-Fi network. Therefore, a comparative study through simulation has performed. Paper results show clearly that deploying level 2 roaming give better results compared with the deployment of level 3 roaming using MIPv4, even whileincreasing the speed of mobility and the number of clients.in future work, a study and an evaluation of mobility performance using mobile IPv6 will been done. Figure 10. DCF vs EDCF packet end-to-end delay. 7. References 1. Gál Z, Karsai A, Orosz P. Evaluation of IPv6 services in mobile WiFi environment, Computer Graphics. 2005; Indian Journal of Science and Technology

7 Hind Sounni, Najib Elkamoun and Fatima Lakrami 2. Wi-Fi Roaming Cisco Blog. Accessed on: 05/06/2014. Available at: 3. Hsieh R, Zhou ZG, Seneviratne A.S-MIP: A seamless handoff architecture for mobile IP. In: INFOCOM 2003 Twenty-Second Annual Joint Conference of the IEEE Computer and Communications IEEE Societies, IEEE; 2003, 3. p Crossref. 4. Park T, Dadej A. OPNET simulation modeling and analysis of enhanced Mobile IP IEEE Wireless Communications and Networking, WCNC 2003; 2003, 2. p Talaat AH, Hussein NA, Elsayed HA, Elhennawy H. Real-time traffic performance for WiFi handovers over MIPv4 versus MIPv6, International Journal of Computer Applications Jul; 26(8): Yokota H, Idoue A, Hasegawa T, Kato T. Link layer assisted mobile IP fast handoff method over wireless LAN networks. In: ACM Press; p Crossref. 7. Grenzinger Y, Jaquemet L. IP MOBILE OpNet. OPNET Technologies, Inc.; p Min-hua Y, Yu L, Hui-min Z. The mobile ip handoff between hybrid networks. The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications; 2002, 1. p Lakrami F, Elkamoun N, Laouidya O. Performance comparison of wireless IEEE a,b,g and n used for Ad-Hoc networks in an e-learning classrooms network, International, Journal of Computer Science and Information Security (IJCSIS) Sep; 15(9): Sounni H, Elkamoun N, Lakrami F. Performance evaluation of access methods with QoS enhancement under mobility impact, International Journal of Computer Applications Dec; 179(2): Indian Journal of Science and Technology 7