Your SlideShare is downloading. ×
Performance evaluation of the mobility management towards 4 g wireless netwo
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Saving this for later?

Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime - even offline.

Text the download link to your phone

Standard text messaging rates apply

Performance evaluation of the mobility management towards 4 g wireless netwo

81
views

Published on

Published in: Technology, Business

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
81
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 1 PERFORMANCE EVALUATION OF THE MOBILITY MANAGEMENT TOWARDS 4G WIRELESS NETWORKS Yang Jie School of Information Technology, Wuhan University of Technology, Wuhan, China Dheyaa Jasim Kadhim Electrical Engineering Department, University of Baghdad, Iraq, Baghdad ABSTRACT The next generation of 4G wireless communication networks is supposed as a communication of different wireless access technologies (vertical communication) permitting the user with the best anywhere, anytime connection and developing the system resource utilization. So mobility management is crucial to ubiquitous computing and requires network management operations to avoid service degradation through this networks heterogeneity. Both location management and handoff management constitute mobility management. Handoff management is one of the mobility management components; it maintains mobile network’s connections active while roaming or switching into a new area. The location management is a tracking process for the active mobile during his roaming without a call. In this work the performance of mobility management is evaluated during handoff and location management processes. Keywords: 4G Wireless Network, Mobility Management, Handoff Process and Location Management. 1. INTRODUCTION The grouping of different wireless communication technologies toward 4G wireless networks should face some expected challenges before realistic practice implementation. One of the major challenges is the mobile station mobility managing among different wireless technologies in order to keep the mobile station connected to the best available wireless network. To merge these vertical wireless networks in one network as an underlay network that can submit a better service at lower cost to the user, as well as improve the overall networks resource utilization. However, achieving INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATION ENGINEERING & TECHNOLOGY (IJECET) ISSN 0976 – 6464(Print) ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October, 2013, pp. 01-10 © IAEME: www.iaeme.com/ijecet.asp Journal Impact Factor (2013): 5.8896 (Calculated by GISI) www.jifactor.com IJECET © I A E M E
  • 2. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 2 these two goals needs a well-designed mobility management system that can achieve the tradeoff between efficient resource utilization and mobile station comprehended QoS [1][2]. Mobility management includes two parts, handoff and location management. When a mobile station moving across the boundary of two neighbor cells, the MSC prepares a new two channels in the new cell to conserve the call from dropping, this operation is called a Handoff Management (HM). The location management (LM) is tracking the active mobile station (powered on MS) during his roaming without a call. While the location of a MS must be known exactly during a call, LM usually means how to track an active mobile station between two consecutive phone calls [3][4]. The most important issues in mobility management are seamless roaming (integration among different 4G wireless networks, QoS assurance, operational costs supported features and a good utilizing of the wireless links (utilizing the wireless links represented by occupying the control channels in the paging and location update operations) [5]. Furthermore, vertical handoffs between radio access networks using different technologies require additional delay for reconnecting the mobile terminal to the new wireless access network, which may cause packet losses and degrade the QoS for real-time traffic [6]. The occupancy of bandwidth, all computational processes in infrastructure of the network, power consumption in MS, and power consumption in the network are form the cost and all of this is a financial cost. Therefore the cost reduction is a very important issue in LM [7]. The objectives of this paper are to focus on handoff management HM, which is an important component of mobility management, and is crucial in enabling seamless mobility across heterogeneous network infrastructures. Also focusing on location management LM with all location management schemes especially paging operation schemes and location update schemes. In order to satisfy seamless mobility a vertical handoff proposed by [8] is considered with some modification using Relative Received Signal (RSS). In order to keep mobile station's location tracking, a proposed location management scheme is submitted, where for each mobile station subscriber we divide his movement pattern into sub-routines depending on randomness in movement during his day's hours. This approach uses a data base to predict the future location of a mobile host based on the history of movement pattern of a mobile host. Simulation is also carried out for different movement patterns (i.e. regular, uniform, random) to predict the future location of a mobile host. 2. MOBILITY MANAGEMENT Seamless roaming or mobility is crucial to ubiquitous computing and requires network management operations to avoid service degradation. Both location management and handoff management constitute mobility management as shown in Figure (1) below. Location management involves two processes. The first process is called location registration, or location update, in which the MT periodically informs the network of its current location, which leads the network to authenticate the user and update its location profile in a database [9]. The second process related to location management is called paging. The handoff management is one of the major functions under mobility management that embraces several aspects of user mobility and mobility support procedures for wireless networks. Handoff management includes wireless terminal handoff management considerations within one network called horizontal handoff and handoff management across different wireless networks which could be based on different wireless access technologies termed vertical handoff [10].
  • 3. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 3 Figure 1. Mobility Management System Mobility management generally deals with automatic roaming, authentication, and intersystem handoff. Automatic roaming includes a set of network functions that allow a subscriber to obtain service outside the home service provider area. These functions are automatic and do not require special subscriber actions. The automatic roaming functions are divided into: •Mobile station (MS) service qualification •MS location management •MS state management •Home location register (HLR), and VLR fault recovery The authentication process requires that end users of the system are authenticated; i.e., the identity of each subscriber is verified. Many researchers propose different mobility models, some of the mobility models are usually used to describe the mobility of an individual subscriber and other models describe the aggregate pattern of all subscribers. In [11] the author used Fluid Flow model to model the mobility of vehicular MS. It requires a continuous movement with infrequent speed and direction changes. In [12], the author used the discrete Random Walk, in this model the author assumed the time is slotted, and the subscriber can make at most one move during a time slot. In [13] the author proposes another model where the current move depends on the previous move, this model called Markov Walk. There are many other mobility models like Cell Residence Time based, Gauss- Markov, Normal Walk, Shortest Path, and Activity Based. For simplicity, and because of these models not required in this thesis, be satisfied by listing them only. Figure (2) illustrates all mobility models [14]. Figure 2. Mobility Models
  • 4. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 4 3. HANDOFF MANAGEMENT SYSTEM Handoff management is one of the mobility management components; it maintains mobile network connections active while roaming or switching into a new area. Depending on the type of attachment, the handoff can be classified into two types: horizontal handoff and vertical handoff. In the horizontal handoff, the MS will not change the technology deployed for its connection even when moving from one point of attachment to another. However, in the vertical handoff, the MS will change the technology when handing off and when moving from one point of attachment to another. The handoff process is divided into three phases [15]: Network Discovery, Handoff Decision and Handoff Implementation. Periodically the system monitors for a better network which the mobile terminal can be handed off. The handoff considerations include several different criteria depending on the algorithms and the goals set for handoff. 3.1 Proposed Handoff Scheme Received signal strength (RSS) is the most widely used criterion to evaluate the performance of Handoff management in the 4G wireless networks because it is easy to measure and is directly relevant to the service quality. There is a close relationship between the RSS readings and the distance between the mobile terminal and its point of attachment. The majority of existing horizontal handover algorithms use RSS as the main decision criterion, and RSS is an important criterion for vertical handoff decision. Since 4G heterogeneous networks will operate in an environment of multiple standards and networks, transfer of packets to a new wireless link will also involve transfer of additional contextual information in order to enable the mobile node to move through different networks, while maintaining its data flows. The proposed vertical handoff scheme will help mobile terminals to choose the best network to connect to among all the available candidates. Here, the focus is only on the research efforts and recent developments on improving the efficiency of vertical handoff decision process. 3.2 Proposed Handoff Scheme Procedure The following steps show the procedure proposed to deal with the handoff scheme for different wireless networks using RSS as a performance criterion: Step 1: RSS measurement: Equation (1) is used to monitor; RSS=P-L-10*n*Log (d)-f (µ, α) (1) Where: P is the transmitted power, L is a constant power loss, n is the path loss exponent, and d is the distance of the MS from the access point. Step 2: RSS average has been calculated using simple average function; RSSavg.=1/N∑RSS (2) Where N is the averaging window. Step 3: The slop estimation has been calculated and as follows; S[k]=( RSSavg[k2]- RSSavg[k1])/(k2-k1) (3) Where k1 and k2 are different distance values.
  • 5. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 5 Step 4: The life time estimation in any wireless network can be calculated as; EL[k]=(RSSavg[k]-ґ)/S[k] (4) Where Ґ is the threshold value in this wireless network. Step 5: The plot of RSS versus distance (k) is as shown in Figure (3) below; Figure 3. RSS vs. Distance (k) As it clear when the distance increase the RSS decrease until reaches the minimum value of attenuation. Step 6: Plot the number of expected handoffs according to distance as shown in Figure (4) below; Figure 4. RSS and No. of Handoffs vs. Distance (k) Where the green curve represents number of handoffs while the blue curve represents RSS curve.
  • 6. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 6 Step 7: Plot the number of handoffs with respect to the velocity of the mobile station as shown in Figure (5) below; Figure 5. Number of Handoffs vs. Velocity of MS According to the result plot we see that: As the velocity increased, the number of handoff will also increase. This scenario happened because of the tendency of fast mobile user to leave the coverage area is high compared to slow mobile user. Therefore, the number of handoff is increasing with respect to the velocity of the mobile user. Step 8: Plot the life time to initiate the handoff according to the velocity of the mobile station as shown in Figure (6) below. From this figure we can notice that as the velocity increased, the starting time for the handoff process would be faster. This is due to the tendency of the mobile user to move out from the coverage area is increasing. Figure 6. Handoff Initiated Time vs. Velocity of MS
  • 7. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 7 4. LOCATION MANAGEMENT SYSTEM With the growing of 4G wireless networks, the need for new services will grow also. Voice call, internet service, multimedia transfer (picture and video), video conference, and other service, all of that is needed to transfer a huge amount of data every second. The track of MS must be known by the network to continually serve that MS by delivering his new calls. To keep the network knowing the MS location at any time, two basic operations can perform that, paging and location update operations. There is a tradeoff between location update and paging, when the MS is never making location update, the cost of location update will be minimized, but we must search all cells to find a MS, the paging cost will be of maximum value. For the inverse case where the MS make a location update frequently, the network will know the MS at any time where he is, and there is no need to paging for a MS, the cost of paging will at minimum while the location update will be of maximum value. However, the total cost can be reduced or one cost can be reduced by putting a band on the other cost [16]. 4.1 Paging Operation The first operation (paging) is accomplished by the cellular network, when an incoming call arrives for a MS, the cellular network will page the MS in a number of cells to find out the cell in which the mobile station is located so the incoming call can be routed to the corresponding base station. The numbers of paged cells depending on how the location update is performed, and Figure (7) explicate different paging schemes [14]. Figure 7. Paging Schemes 4.2 Location Update Operation The second operation (location update) is performed by the MS, it informs the network with his resent location and this operation can perform in many schemes, Figure (8) explicates location update schemes [14]. The location update operation can be classified as global or local, a location update scheme is local when the MS allowed to decide when and where it make location update, and called global if all MSs at the same set of cells generate the location update. Also, this operation can be classified as static and dynamic, it will be static when a predetermined set of cells allowed to MS to generate location update in it regardless of its mobility, and it will be dynamic when the MS can generate location update in any cell depending on its mobility.
  • 8. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 8 Figure 8. Location Update Schemes 4.3 Proposed Location Update Scheme The proposed location update scheme predicts the future location of a mobile host based on the history of its movement pattern. Movement pattern (Pn) is the history of movement of a mobile host recorded for a period of time (Tn) where n is the number of regular time intervals at which the mobile host movements are recorded. The time interval can be minutes, hours, days, etc. The movement pattern Pn can be represented by a data at regular time interval, t1, t2 ...tn. Let the movement pattern Pn={p1, p2, ...,pn} be recorded for a mobile station, where Pi indicates the movement of a mobile host during time ti, and we define the movement in terms of direction and distance travelled by a mobile station during the time interval ti. Then Pi is represented by a pair (di,dsi). Where di is the possible direction in which a mobile host moves at ith time interval. For example, if we consider four possible directions, North, East, South and West, of movement of a mobile station, then di={North, East, South, West}. If a mobile host moves towards North direction at ith time interval, then di = North. And dsi is the distance travelled by a mobile host at ith time interval. Here, the distance travelled may be number of cells, kilometers, meters, etc. For example, if a mobile movement pattern is recorded for three time intervals (n=3) with direction of movements, North, East, East and the distance travelled is 2, 1, and 3 units, then the movement pattern is, P3={p1, p2, p3}={(d1, ds1), (d2, ds2), (d3, ds3)}={(North, 2), (East, 1),(East, 3)}. Note that we divided the service area into four location area with each contain eight cells. The Procedure of our proposed location update scheme as follows: Step 1: For the example above, the proposed scheme is assumed that there is a user's database which stored the last four movement cells of the user and then takes the four values. Step 2: Next, the time will calculate and depended on it, the proposed scheme will go to the appropriate database.
  • 9. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 9 Step 3: a. If the time is between (7 A.M -3 P.M) then the program will go to the work database and then go the next step. b. If the time is between (4 P.M -6 P.M) then the program will go to the road database and then go the next step. c. If the time is between (7 P.M -6 A.M) then the program will go to the home database and then go the next step. Step 4: The proposed scheme will compare the last four movement cells for the user with the patterns that stored in the appropriate database that will selected from the previous step. a. If the match is done then the predicted cell, location area, movement direction and distance will be obtained. b. If the match is not occur then the scheme will propose that the prediction movement cell for the user is known, so the four movement cells getting from the user database with the given prediction movement will make new record added to the appropriate database that will selected before. c. Then the user database will then update with the last four movement cells (taking into account the prediction movement as the last movement). 5. CONCLUSIONS In this work, the mobility management is enhanced into its two directions, handoff management and location management. From the above simulation results for the proposed handoff scheme, it could be concluded that algorithm using lifetime (i.e. using the equation of delay), gives better results compared with the results using RSS. Also these simulation results show that as the velocity increased, the number of handoff will also increase. This scenario happened because of the tendency of fast mobile user to leave the coverage area is high compared to slow mobile user. Therefore, the number of handoff is increasing with respect to the velocity of the mobile user. On the other side, we propose a prediction-based location management in a mobile network. This approach uses a data base to predict the future location of a mobile host based on the history of movement pattern of a mobile host. Multiple move prediction is designed for predicting the future location of a mobile host. The performance of the method has been verified for prediction accuracy by considering different movement patterns of a mobile host. 6. REFERENCES [1] I.F. Akyildiz, Jiang Xie and S. Mohanty, "A survey of mobility management in next- generation all-IP-based wireless systems", IEEE Wireless Communications Journal, Vol. 11 No. 4, 2004. [2] R. Berezdivin, R. Breinig and R. Topp, " Next-generation wireless communications concepts and technologies", IEEE Communications Magazine, Vol. 40 No. 3, 2002. [3] Bar-Noy, I. Kessler and M. Sidi, " Mobile users: to update or not to update?", 13th Proceedings IEEE INFOCOM, Toronto, 1994. [4] J. Cowling, "Dynamic Location Management in Heterogeneous Cellular Network", Thesis, University of Sydney, Australia, 2004. [5] N. Goel, N. Gupta and P. Kumar, "A speed based adaptive algorithm for reducing paging cost in cellular networks", 2nd IEEE International Conference on Computer Science and Information Technology (ICCSIT), Beijing, 2009.
  • 10. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 4, Issue 5, September – October (2013), © IAEME 10 [6] S. M. Joseph and I.F. Akyildiz, "Mobile user location update and paging under delay constraints", Wireless Networks Journal, Vol. 1 No. 4, 1995. [7] K. H. Chiang and N. Shenoy,"A 2D Random Walk Mobility Model for Location management Studies in Wireless Network", IEEE Transaction on Vehicular Networks, Vol. 53 No.2, 2004. [8] B. Liang, A. Zahran and A. Saleh, "Application Signal Threshold Adaptation for Vertical Handoff in Heterogeneous Wireless Networks", International Federation for Information Processing (IFIP), 2005. [9] P. Bilurkar and N. Rao, "Application of Neural Network Techniques for Location Prediction in Mobile Networking", Proceedings of the 9th International Conference on Neural Information Processing, 2002. [10] K. Majumdar and N. Das, "Neural Network for Location Management in Mobile Cellular Communication Networks", Conference on Convergent Technologies for the Asia-Pacific Region (TENCON), 2003. [11] J. Muhammed and A. Hussain, "New Neural Network Based Mobile Location Estimation in Urban Propagation Models", 7th International Multi Topic Conference, 2003. [12] S. Mitra and S. Das Bit,"Neural Network Based Precise Location Identification in a Cellular Mobile Network", IEEE International Conference on Personal Wireless Communications, 2005. [13] S. Akoush, A. Sameh,"The Use of Bayesian Learning of Neural Networks for Mobile User Position Prediction", Proceedings of 16th International Conference on Computer Communications and Networks, 2007. [14] B. P. Vijay, Kumar and P. Venkataram,"Prediction Based Location Management Using Multilayer Neural Networks", Journal of Indian Institute of Science, 2002. [15] X. Li and R. Salleh, "Handoff Techniques for 4G Wireless Mobile Internet", Information Technology Journal, Vol. 6 No. 5, 2007. [16] Y. B. Lin, "Reducing Location Update Cost in a PCS Network", IEEE/ACM Transaction on Networking, Vol. 5 No. 1, 1997. [17] Dheyaa Jasim Kadhim, Tagreed Mohammed Ali and Faris A. Mustafa, “Location Prediction in Cellular Network using Neural Network”, International Journal of Computer Engineering & Technology (IJCET), Volume 4, Issue 4, 2013, pp. 321 - 332, ISSN Print: 0976 – 6367, ISSN Online: 0976 – 6375. [18] C.Amali, Bibin Mathew and B.Ramachandran, “Intelligent Network Selection using Fuzzy Logic for 4G Wireless Networks”, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 4, Issue 2, 2013, pp. 451 - 461, ISSN Print: 0976- 6464, ISSN Online: 0976 –6472. [19] Dheyaa Jasim Kadhim and Sanaa Shaker Abed, “Performance and Handoff Evaluation of Heterogeneous Wireless Networks (HWNS) using Opnet Simulator”, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 4, Issue 2, 2013, pp. 477 - 496, ISSN Print: 0976- 6464, ISSN Online: 0976 –6472.