A Survey on Signaling Load in Mobility Management

ISSN: 2231-4946 Volume IV, Special Issue, December 2014 International Journal of Computer Applications in Engineering Sciences Special Issue on Advances in Computer and Communications www.caesjournals.org Manuscript Received: 01/10/2014 Revised: 17/11/2014 Online Published: 05/12/2014 A Survey on Signaling Load in Mobility Management Hemali Vithalani Department of Computer Engineering, Faculty of PG studies-mef Group of Institutions, Rajkot-360003, India. vithalani.hemali@gmail.com Abstract--In this paper survey on various approaches for reducing signaling load is done. The objective of this work is to provide various methods for reducing signaling load in Mobile Internet Protocol (MIP) network. In MIP lots of binding related message needs to be exchange to provide mobility to mobile node. Frequent exchange of binding related message increases the signaling load. Higher signaling load may reduce the scalability of network. Higher signaling load can even overload the mobility agent as they need to process more binding related message. Thus most of the work associated with reducing the signaling load mainly tries to minimize the number of binding related message. Keywords-- Mobile, Mobility Management, Signaling, Internet I. INTRODUCTION Mobile IP is standard which provides uninterrupted connectivity to mobile node. MIP provides routing independent of location and efficient scalable mechanism for roaming users on the Internet. There are mainly three aspect of MIP: discovery mechanism to find out new connection point, registration mechanism to register with the current location and packet transmission mechanism to transmit datagram [9]. There are two variation of MIP: IPv4 and IPv6. Mobile IPv6 provides streamlined mobility support and can accommodate the need of huge address space to enact all-ip network and internet of things. Internet of things defines that mobile node must be able to communicate with each other regardless of its mobility pattern [7]. Despite of having many advantages MIPv6, it intensify signaling load as it uses same mechanism for handling local mobility and global mobility of mobile node. MIPv6 also increases the handoff delay. To overcome this problems MIPv6 is extended to Hierarchical Mobile IPv6 (HMIPv6) by using Mobile Anchor Point (MAP). HMIPv6 provides transparency to both home agent and corresponding node. Fig. 1 [4] shows the location updating process in HMIPv6. Two addresses are used for communication: RCoA (Regional Care of Address) which is address of MAP and LCoA (Local Care of Address) which is mobile node current temporary address. MAP forward all the packet of HA and CN to MN LCoA therefore MN need not to send BU message to HA and CN during intra domain movement. 1 P a g e

Hemali Vithalani CN N HA Packet Binding Update message Internet CN N AR1 MAP 1 MAP 2 AR2 AR3 Domain 1 MN Movement MN Domain 2 Fig. 1 Hierarchical mobile IPv6 [4]. Mobility in MIP can be achieved by sending Binding Update (BU) and Binding Refresh (BR) message as it allow to maintain reachability and on-going connection between Mobile Node (MN) and Correspondent Node (CN) [4]. Whenever a MN changes its location it needs to send BU message to its HA and relevant CN (if any). HA and CN acknowledge BU message by sending BACK (Binding Acknowledgment) message. BU message mainly contains information about binding lifetime and new location. Binding lifetime can be said as time interval after which mobile node needs to re-register with the current CoA (Care of Address). When binding lifetime is close to expire MN need to send binding refresh message. It is very essential to determine the binding lifetime as it has remarkable impact on system performance. Binding refresh rate is directly depend on binding lifetime. Longer binding lifetime causes more number of BR message. And more number of BR massage causes higher signaling load. Thus most of mobility management strategies attempt to reduce signaling load by minimizing number of binding related message. Recent work defines that reducing signaling load is challenging job. Signaling load can cause reduced scalability, processing overhead at the mobility agents, fragmentation overhead [5]. Key terms: 1). Binding update message: Generated when MN changes its location from one location to other location. 2). Binding refresh message: Generated when MN need to re-register with the current location. 3). Binding acknowledgment message: Mobility agent acknowledges binding update and binding refresh message by sending binding acknowledgment message. 4). Binding lifetime: Time interval after which MN need to re-register with the current location. 5). Care of Address (CoA): CoA can be said as mobile current temporary address. This paper is organized as follows: Challenges and issues for reducing signaling load is defined in Section 2; literature review about various approach of signaling load is addressed in Section 3; comparative analysis is discussed in Section 4; finally, conclusion is addressed. 2 P a g e

A Survey on Signaling Load in Mobility Management II. CHALLENGES AND ISSUE Escalated popularity of Internet and availability of Internet in wireless mobile communication leads to inevitable need of mobility management which is most challenging issue for wireless communication over internet. Mobility management provide uninterrupted Internet services to mobile node when it moves from one location to other location. There are two aspect of mobility management: location management and handoff management. Location management mainly deal with location registration and call delivery [9]. To register with location, mobile node needs to send binding update and binding refresh message. Mobile node needs to send binding update message when it moves from one location to other and to re-register with the current location mobile need to send binding refresh message. Mobility agents acknowledges binding update and binding refresh message by sending binding acknowledgement message. This binding related messages may causes signaling load on the network. Thus when large number of mobile node moves from one location to other location causes more exchange of binding related messages and which in turn escalate the signaling load. Higher signaling load reduces the scalability and increases the processing overhead at the mobility agent. Lots of research work is exists for mobility related issue. All of this work focus on minimization of handoff latency, signaling load and packet tunneling cost [2]. Other issue in MIP network can be define as determination number of layer in the architecture of network. There must be some accepted hierarchy of layer in the network [2]. Efficient management of location database and tracking and finding mobile terminal are also important issue in MIP network. III. LITERATURE REVIEW This section introduce the existing methods for reducing signaling load. Tanapong Poungkong and Watit Benjapolakul [1] have shown the comparison of Mobile IP, Mobile IP with paging support, Mobile IP Regional Registration and Mobile IP Regional Registration with paging support. Paging mainly used to find out the location of idle MN before establishing call. Paging concept is introduced to overcome the issues with the MIP by reducing signaling cost. MIP with paging reduces the signaling load by the concept as no registration is required in case MN is idle and moving within the same paging area. Mobile IP Regional Registration does few improvement in MIP with paging by using gate way foreign agent. In Mobile IP Regional Registration MN register with the new domain by sending regional registration message to only gateway foreign agent when it changes its location from one domain to other with in the coverage area of same gateway foreign agent. Mobile IP Regional Registration with paging support, incorporates paging with the Regional Registration. In this schema HA forwards the packet of MN to gateway foreign agent. On receiving the packet gateway foreign agent check the state of MN, if MN is active then send that packet to froing agent where MN is currently registered and if the MN is in idle state then paging request is sent by gateway foreign agent to all the foreign agent with in the same paging area. Nitul Dutta and et al. [2] have present cost analysis of Three Layer MIPv6 (TLMIPv6) and hierarchical MIPv6 (HMIPv6). Authors have evaluated cost analysis in terms of signaling cost, tunneling cost and packet dropping probability. HMIPv6 split the network into two parts backbone domain and local domain. Anchor agent is attached with both domain which provides transparency to HA and CN. Two kind of address are assign to MN: CoA (Care of Address) and RCoA (Regional CoA). LCoA and RCoA changes with mobility of MN. If there is change in LCoA then MN needs not to send binding update message to HA and CN. This will reduces the signaling load in domain network. TLMIPv6 also split the network into two domain inside and backbone domain. The inside domain is further split into three domain as local, regional and global domain. Three divergent anchor agent are used to cover this three domain. Three different address are used which are CoA IP address of MAP, RCoA IP address of RMAP (Regional MAP) and GCoA IP address of GMAP (Global MAP). Here only the change in GCoA requires to update HA and CA by sending BU message. This will significantly reduce the signaling load. Z. D. Wu [3] have proposed method of determining optimized binding lifetime in MIPv6. In this paper author have defined that binding lifetime has remarkable impact on system performance. If binding lifetime is set to smaller values then it will increases the binding related messages to HA and CN and in turn increases the signaling load of the network. If binding lifetime is set to large value then it may occupy more space in Binding Cache and Binding Update list. Thus author have proposed an algorithm for dynamically determining binding lifetime in context of MIPv6. Algorithm for determining binding lifetime uses the parameters such as user mobility, traffic workload, and network structure. An analytical mathematical model is also introduced in the paper for estimation of optimal lifetime. Sun Ok Yang and et al. [4] have also present the scheme for lifetime determination in context of HMIPv6. For determining binding lifetime authors have proposed new profile based determination schema. This schema is based on the observation that most of the people follows the regular movement. Thus each user can keep local profile 3 P a g e

Hemali Vithalani which contain the movement logs. This profile can be used for estimating binding lifetime for binding update message. Therefore it can be used for reducing the number of binding related message in turn can reduce the signaling load in the network. Local profile contains the parameters such as subnet identifier, the arrival time and the departure time which can used for estimation of binding lifetime. Ki-Sik Kong and et al. [5] have shown the analysis of signaling load in MIPv6 and HMIPv6. Authors have proposed novel analytical approach for evaluating signaling load in MIPv6 and HMIPv6. Authors have identified that signaling load can cause reduce scalability, Processing overhead at the mobility agents, fragmentation overhead. Increased number of MN in foreign network can cause more number of BU and BR messages and which in turn increases the signaling load. Processing overhead can be increased as the HA and MAP need to evaluate binding related message and more number of binding related message requires more processing. Packet tunneling requires more bandwidth which increases the size of packet this can cause the fragmentation overhead. Therefore it is very essential to reduce the signaling load. To assume the mobility movement of MN authors have uses fluid flow model. To find out location updating cost authors have consider the location cost as summation of binding update cost, binding refresh cost, packet tunneling cost, inside domain signaling costs, outside domain signaling cost and total signaling costs. Young J. Lee and et al. [6] proposed new schema for reducing link and signaling cost in MIP. Packet transmitted in MIP follows longer path then the required, it is known as triangle routing problem. To overcome this problem many protocols are proposed for transmitting the packet to optimal path. But this protocol impose high signaling and processing cost on network. Thus authors in this paper have proposed a new schema for reducing signaling cost by route optimization. Author have computed total cost as summation of link cost and signaling cost. To compute signaling cost signaling function is used to determine signaling and processing load generated by route optimization. To compute link cost link cost function is used for determining network resources required by routing path. This approach uses the morkovian decision model to estimate optimal routing path. For the simplification of decision process authors have restricted the model to intra domain handoff. IV. COMPARATIVE ANALYSIS This section shows the comparison of various method used for reducing signaling load in MIP network. To reduce the signaling load all the method discuss below mainly tries to minimize the number of binding related message. By reducing number of binding related message one can reduce the processing load at mobility agent, minimizes signaling load of network, and also one can prevent the unnecessary use of bandwidth. Signaling load can even reduce by optimizing the binding lifetime as binding refresh rate is directly depend on binding lifetime. Table 1 shows the comparison of various method used for reducing signaling load. 4 P a g e

A Survey on Signaling Load in Mobility Management paper [1] MIP [2] TABLE 1 COMPARISON OF VARIOUS APPROACHES FOR REDUCING SIGNALING LOAD Parameters for evaluating Mobility Protocol Remarks signaling load model HLMIPv6 TLMIPv6 [3] MIPv6 [4] HMIPv6 [5] [6] MIP MIPv6 HMIPv6 Number of base stations in paging area, cell perimeter and mobile node Velocity. Signaling cost, tunneling cost and packet dropping probability. User mobility, traffic workload and network structure. Subnet identifier, the arrival time and the departure time. Binding update cost, binding refresh cost, packet tunneling cost, inside domain signaling costs outside domain signaling coast and total signaling costs. link cost and signaling cost Fluid flow Random walk Not applicable Not applicable Fluid flow Not applicable Paging MIP and Regional registration requires less registration message. Thus signaling cost of paging MIP and Regional Registration is less than the traditional MIP and Regional Registration with Paging Mobile IP. Thus paging MIP and Regional registration MIP provide higher scalability. When binding refresh rate is high, HMIPv6 provide better performance than the TLMIPv6. TLMIPv6 restrict binding update to local domain so it gives better performance for different values of binding lifetime of anchor agent. An algorithm for dynamically determining binding lifetime in context of MIPv6 is proposed in this paper but the drawback of this algorithm can be said as it requires to evaluate the approximate distance between MN and CN in HA. This paper provides the approach for determining binding lifetime by using paging approach. This approach can reduce signaling overhead but cannot achieve the reliable result when number of log per subnet is less than the specified threshold value. Signaling bandwidth consumption of HMIPv6 is larger in domain compare to MIPv6 because HMIPv6 requires extra message to MAP. Thus cost required in HMIPv6 is larger than the MIPv6. For the simplification of decision process authors have restricted the model to intra domain handoff. V. CONCLUSION It is very important to reduce signaling load as increased signaling load can increase the processing overhead of mobility agent and reduces the scalability of network in turn degrade the overall network performance. Therefore this paper discuss the various approach of reducing signaling load in MIP network. One of the method of reducing signaling load can be said as optimized the binding lifetime. Optimized binding lifetime can reduce number of binding related messages in turn reduces the signaling load. Therefore most of the work related to reducing signaling load tries to reduce signaling load by reducing number of binding related messages. paper. ACKNOWLEDGMENT I am thankful to Professor Nitul Dutta for his support and precious guidance throughout the completion of this REFERENCES [1] Tanapong Poungkong and Watit Benjapolakul, A Comparative Analysis on Signaling Cost of Mobile IP Regional Registration with Paging Support,IEEE Communications Society, pp. 1415-1420, 2005. [2] Nitul Dutta, Iti Saha Misra, Cost Analysis of a Three Layered mipv6 (tlmipv6) Mobility Model and hmipv6, (IJCSE) International Journal on Computer Science and Engineering, Vol. 02, No.01S,pp.36-46,2010. [3] Z. D. Wu. An approach for optimizing binding lifetime with mobile IPv6, Proc.s of the 28th Annual IEEE International Conference on Local Computer Networks, 1(1), 2003. [4] Sun ok yang, sungsuk kim and chong-sun hwang, Profile-Based Lifetime Determination Schemes for Mobility Management in hmipv6*, journal of information science and engineering 22, pp.659-674, 2006. [5] Ki-Sik KONG, MoonBae SONG, KwangJin PARK and Chong-Sun HWANG, A Comparative Analysis on the Signaling Load of Mobile IPv6 and Hierarchical Mobile IPv6: Analytical Approach, ieice trans. inf. & syst., vol.e89d(1), pp. 139-149, January 2006. 5 P a g e

Hemali Vithalani [6] Young J. Lee and Ian F. Akyildiz, A New Scheme for Reducing Link and Signaling Costs in Mobile IP, IEEE transactions on computers, vol. 52(6), pp. 706-711, june 2003. [7] Nitul Dutta, Iti Saha Misra, Multilayer Hierarchical Model for Mobility Management in IPv6,A Mathematical Exploration23,Vol. 78(2),pp.1413-1439, sept2014. [8] D. B. Johnson, C. Perkins, and J. Arkko, Mobility support in ipv6, RFC 3775, 2004. [9] Charles E. Perkins, Mobile IP, IEEE Communications Magazine, pp.84-99, May 1997. [10] Jun-Zhao Sun*a, Douglas Howie**a, and Jaakko Sauvola***a, Mobility management techniques for the next generation wireless networks [online]. Available: http://www.mediateam.oulu.fi/publications/pdf/85.pdf. 6 P a g e