S.Zahoor Ul Huq et al. / International Journal of Engineering Science and Technology
Vol. 2(3), 2010, 227-231 ANALYSIS OF EFFICIENT ADDRESS
ALLOCATION SCHEMES IN MOBILE AD
HOC NETWORKS
S.ZAHOOR UL HUQ*1, Dr. K.E.SREENIVASA MURTHY2, Dr. B.SATYANARAYANA3, D.KAVITHA4
1
Associate Professor, Computer Science & Engineering Department, G. Pulla Reddy Engineering College,
Kurnool, Andhra Pradesh, India
s_zahoor_2000@yahoo.com
2
3
Principal, G. Pullaiah College of Engineering & Technology,
Kurnool, Andhra Pradesh, India
kesmurthy@gmail.com
Professor in Master of Computer Applications Department, Sri Krishna Devaraya University,
Anantapur, Andhra Pradesh, India
bachalasatya@yahoo.com
4
Associate Professor, Computer Science & Engineering Department, G. Pulla Reddy Engineering College,
Kurnool, Andhra Pradesh, India
dwaramkavithareddy@yahoo.com
ABSTRACT
A Mobile Ad-hoc Network (MANET) can be implemented anywhere where there is little or no communication
infrastructure, or the existing infrastructure is inconvenient to use. A number of mobile devices may connect together to
form one network. Address auto-configuration is an important issue for ad hoc networks in order to provide
autonomous networking and self-management. In this paper we take into account various parameters for designing an
efficient address allocation scheme in MANETs and consider the best of them to build an efficient protocol for Address
allocation in MANETs.
Keywords: IP Address Auto-Configuration; Ad Hoc Address Allocation, Address Conflicts, Resolution schemes, DAD
Schemes, Addressing Structure.
1. Introduction
In the wired networks the address of the devices or nodes is static and does not change as the autoconfiguration is done by the Dynamic Host Configuration Protocol (DHCP)[4]. But, the addresses of mobile or
wireless devices change from time to time. The wireless nodes, moving from one place to another have different points
of presence in the network. An auto-configuration method such as DHCP, unfortunately is not suitable for mobile and
wireless devices. Another area where DHCP and other solutions for fixed networks, such as Internet Engineering Task
Force (IETF) Zeroconf[5], do not provide a good solution is mobile ad hoc networks (MANETSs)[1]. Such networks
consist of mobile devices that communicate with each other with wireless communication technologies in an ad hoc
fashion. The nodes also act as routers and relay packets that cannot reach the destination in one hop. This makes the
network multihop, and this multihop characteristic of a MANET makes existing addressing solutions for fixed networks
inadequate. The protocols that are designed for a single LAN topology, with the assumption that every node can reach
all the others by link layer broadcasts or multicasts are not true for most MANETs. All nodes are not guaranteed to be
reachable through link local broadcasting. Different protocols are therefore required for MANETs.
We cannot trust the Mac Addresses for data transfer as Mac Addresses works at Layer 2, and the another
reasons are the Mac Addresses are not unique as some manufacturers sell network adapters with non-registered MAC
addresses or the MAC address may be corrupt while manufacturing. Most of the network adapters allow users to
change the MAC address to arbitrary values and some of the adapters may not be having IEEE MAC addresses at all.
Above all because of the privacy interface identifiers are generated randomly [2].
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Vol. 2(3), 2010, 227-231 The major requirement of ad hoc addressing schemes is ensuring the uniqueness of node addresses so that no
ambiguity appears when they try to communicate. This is not as trivial as it seems, especially because of the dynamic
topology of ad hoc networks. A MANET can be split into several parts and several MANETs can merge into one. Tens
to thousands of nodes coexisting in a single network may participate concurrently in the configuration process.
Moreover, the wireless nature, such as limited bandwidth, power, and high error rate makes the problem even more
challenging. Besides handling a dynamic topology, the protocols much take into account scalability, robustness, and
effectiveness.
Various protocols use various initial methods for address allocation like Perkins et al[9] uses Duplicate
Address Detection (DAD), Boleng[13] uses Agent discovery, Patchipulusu [14] uses Leader Discovery and PACMAN
[15] directly. Also most of the papers discuss about the IP auto-configuration when a new node joins or when the subnetwork joins another network but none of them discusses when a new network is initialized and there is no assignment
of addresses or there is no Leader and there is no coordinator in the network. Consider the case during Military
Operations or during the war where the soldiers carry the mobile devices which help them in communication among
themselves, which happens in a remote place where is no network available, in such places a new network has to be
initialized to initiate the communication among the devices. In such a place there are no address assignment done to the
nodes or there is no DAD scheme or there is no Leader or coordinator among the mobile devices. We want to build IP
address auto-configuration for such an network.
Section 2 discusses about the requirements for IP Addresses configuration. Section 3 focuses on two types of
Addressing Structure, Section 4 discusses about Allocation Methods, Section 5 regarding Addressing and finally
Section 6 Conclusion.
2. Requirements
The Ad Hoc address auto-configuration protocol must detect and resolve address conflicts in a timely manner
and on an ongoing basis, and it should allow the conflicted address replaced with another. The Address allocation
scheme should minimize the damage, such as loss of delivered packets due to address replacement. Addresses should
be allocated or auto-configured in a way that minimizes the probability that two or more nodes will have the same
address.
The address allocation scheme must capable of providing IP address in a reasonable delay, must be capable of
discovering whether an IP address is currently in use or not, must detect and resolved IP address conflicts in a timely
manner and on an ongoing basis, and must timely validate auto-configured IP addresses when powering up or rebooting
and also may timely validate auto-configured IP addresses when moving into a new network. The scheme should be
able to process the address conflict due to manual address configuration, should minimize the influence of autoconfiguration traffic on the ongoing MANET communication performance, and may get the aid of ad hoc protocol so as
to detect duplicate addresses. This scheme should not me modifying the existing MANET routing protocol and may get
the aid of ad hoc routing protocol so as to minimize the probability that two or more nodes will have the same address.
When MANET Partitions merge, ad hoc address auto-configuration protocol should be performed in the way it
avoids congestion caused by messages sent for the purpose of duplicate address detection. Should minimize the
damage, such as loss of delivered packets due to address replacement for supporting the survivability of upper-layer
sessions, such as TCP. Using this scheme the IP addresses are allocated to mobile nodes in a way that minimizes the
probability that two or more nodes will have the same address. The reclamation of the addresses unused any more may
be considered. An IP address is assigned only for the duration the node stays in the network. When the node departs the
network, its IP address may become available for assignment to other nodes. In this case, address auto-conf protocol
should not immediately reuse the released IP addresses as soon as they become available, in order to reduce address
conflicts.
3. Addressing Structure
The two types of addressing Structure followed are flat and hierarchical. Networks generally use a flat
addressing scheme (e.g. the MAC hardware address, the IP network address), where the actual address used does not
have a relationship to the hierarchical name which it represents. This type of address is easily administered and assumes
no specific network topology.
Although easy to administer, a flat address scheme provides no indication of the location of a computer in the
network. It is therefore complex to arrange routing between end systems in a large flat network. The social security
system is an example of a flat address space. Social security numbers are allocated to people in the order in which they
are processed in a particular area. The number itself says nothing about the individual or where she/he may be found
(the only information is the social security office where the person's records were processed!)
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Vol. 2(3), 2010, 227-231 Whereas in the hierarchical address structure, the network may use this information to help perform the
routing. A typical example of a hierarchical addressing system is the telephone numbering scheme. For example, the
international phone number 643482009 can be parsed as 64-348-2009 where 64designates a country code (New
Zealand), 3 an area within the country (city of Christchurch), 48 a telephone exchange, and 2009 a subscriber line.
Both hierarchical and flat address spaces have advantages. Hierarchical addresses can simplify routing, since
successive steps may depend on individual fields. For example, successively locating a country, an area, a central office,
and a subscriber. It is also simple to assign hierarchical addresses without the need for a central authority. Abbreviation
of addresses for local use is easy; for example, country and area codes do not need to be dialed for local phone calls. On
the other hand, hierarchical address must be changed if subscribers move and the address space may be inefficiently
used since the number of addresses available at a hierarchy level is largely independent of how many are needed. Both
types of addressing are common.
In our case the network is small/medium and the number of nodes are limited, the addressing type followed is
local. The type of Ad Hoc network is mostly standalone. Supports handling network merging and partitioning. There is
no Leader whose functionality is address maintenance.
4. Allocation Method
The IP Address assignment can be done by using either Conflict detection allocation (CDA) or Conflict-free
allocation (CFA). CDA works on selecting an address from a pool of available addresses and then performing DAD
(Duplicate Address Detection). DAD is intended to detect conflicts with local addresses. In contrast to CDA, no
duplicate detection is performed by the CFA method. The uniqueness of the allocated address can be assured without
any cross check.
Duplicate Address Detection (DAD) is important to avoid misrouting. DAD is of two types Strong Dad and Weak
DAD.
Strong DAD: Let Ainode(t) be the address assigned temporarily to node inode at time t. Ainode(t) is undefined when node
inode has not chosen any address at time t. For each address addr, addr != undefined, define set saddr(t) = { j | Ainode(t) =
addr}. That is saddr(t) is the set of nodes that are assigned address addr at time t. A Strong DAD algorithm must ensure
that, within a finite bounded time interval after t, at least one node in saddr(t) will detect that | saddr(t) | > 1.
The Strong DAD is impossible under certain conditions if partitions can occur for unbounded intervals of time then
strong DAD is impossible. Say, two partitions, and remain so for an unbounded interval of time. In this case if two
nodes in the two partitions choose the same address addr, no algorithm can detect these duplicates within a bounded
time interval, since the nodes in the two partitions cannot communicate with each other in a timely manner. In practice,
particularly in presence of partition, it may not be possible to bound message delays
Weak DAD: is proposed in [3], by which the messages can be delivered correctly even when duplicate addresses occur:
(i) Delays in ad hoc networks are not always bounded.
(ii) Even if the message delays were bounded, determining the bound is not trivial (Particularly when size of the
network may be large and possibly unknown).
(iii) Impossibility of Strong DAD in presence of unbounded delays implies that timeout-based duplicate address
detection schemes will not always detect duplicate addresses.
(iv) Weak DAD, unlike strong DAD, can be achieved despite unbounded message delays.
(v) Weak DAD relaxes the requirements on duplicate address detection by not requiring detection of all duplicate
addresses.
(vi) Informally, weak DAD requires that packets “meant for” one node must not be routed to another node, even if the
two nodes have chosen the same address. Weak DAD is proposed in [3], by which the messages can still be delivered
correctly even when duplicated addresses occur.
Protocol overhead is caused by processes that must be completed by each protocol. Consider a network of N
nodes then [6], [7], [8], [9] uses the CDA allocation method and has the protocol overhead of O(N2). Where as [10],
[11], [12] uses the CFA allocation method and has the protocol overhead of O(N).
Although Weak DAD and other methods are existing, Strong DAD is considered to be efficient to find the
uniqueness of the IP Addresses. In our Scheme we propose to implement CDA & CFA methods for address allocation.
First we propose to use CFA then CDA
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Vol. 2(3), 2010, 227-231 5. Addressing
The address type can be classified as Tentative and Definite. A Tentative address is the address whose
uniqueness is being verified, prior to its assignment to the node. This type of address is not considered assigned to the
node in the usual sense. Before the IP Address is assigned to a node and used, however, a node must attempt to verify
that this tentative address is not already in use by another node in the network. Specifically, it can be done by Strong
DAD containing the tentative address as the target. If another node is already using that address, it will return a
message saying so. If another node is also attempting to use the same address, it will also send the message for the
target as well, and on getting the acknowledgment of it, the node has to change its tentative address and repeat the
process again. The exact delay time for the DAD is network specific and may be set by network management. An
address on which the DAD procedure is applied is said to be tentative until the procedure is completed successfully. A
tentative address is not considered “assigned to a node” in the traditional sense.
It should be noted that DAD must be performed prior to assigning an address to a node in order to prevent
multiple nodes from using the same address simultaneously. If a node begins using the address in parallel with DAD,
and another node is already using the address, the node performing DAD will erroneously process traffic intended for
the other node, resulting in such possible negative consequences as the resetting of open TCP connections. The
detection and resolution of address conflicts are the indispensable part of address auto-conf protocol operation
6. Conclusions
Much effort has been put into the creation of routing algorithms to handle route setup and maintenance. Most
researches in the routing area assume that all hosts already have allocated their unique addresses. This assumption is
critical and has to be resolved. A mobile device in a MANET must be assigned a free IP address before it may
participate in communication. Dynamic address allocation and management is a very difficult problem and challenging
in MANETs where nodes join the network and depart from the network unexpectedly. The random mobility of nodes in
MANETs can lead to frequent and unpredictable topology changes. In this paper we have presented an exhaustive
analysis of different techniques. We described various available techniques and explained the different criteria to
include them in the protocol.
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
Mobile Ad-hoc Networks (MANET), www.ietf.org/html.charters/ manet-charter.html
Killian A. Weinger, “Passive Autoconfiguration of Mobile Ad hoc Networks”, IEEE Journal of Selected areas in communications. Vol. 23.
No.3 March 2005 p.no.507-519
N. H. Vaidya, “Weak Duplicate Address Detection in Mobile Ad Hoc Networks,” Proc. ACM MobiHoc ’02, June 2002, pp. 206 -16.
R. Droms, “Dynamic Host Configuration Protocol,” IETF RFC 2131, Mar. 1997.
E. Guttman, “Autoconfiguration for IP Networking: Enabling Local Communication,” IEEE Internet Comp., vol. 5, no. 3, May-June 2001,
pp.81-86
I.Park, Y. Kim, and S.Lee, “IPv6 Address Allocation in Hybrid Mobile Ad Hoc Networks,” Proc. 2nd IEEE Wksp. Software Technologies
for Future Embedded and Ubiquitous Sys., p. 58.
J. Jeong, “Ad Hoc IP Address Autoconfiguration,” IETF Internet draft, Jan. 2006.
S. Ruffino and P. Stupar, “Automatic Configuration of IPv6 Addresses for Nodes in a MANET with Multiple Gateways,” IETF Internet
draft, Feb. 2006.
C. Perkins et al., “IP Address Autoconfiguration for Ad Hoc Networks,” IETF draft, 2001.
D. O Mahony and S. Toner, “Self Organizing Node Address Management Protocol for Ad Hoc Networks,” LNCS, 2003, pp. 476–83.
C. Jelger and T. Noel, “Proactive Address Autoconfiguration and Prefix Continuity in IPv6 Hybrid Ad Hoc Networks,” Proc. IEEE
COMSOC, Sept. 2005.
P. Patchipulusu, “Dynamic Address Allocation Protocols for Mobile Ad Hoc Networks,” M.Sc. thesis, Comp. Sci., Texas A&M Univ.,
2001.
J. Boleng, “Efficient Network Layer Addressing for Mobile Ad Hoc Networks,” Proc. Int’l Conf. Wireless Networks, June 2002, pp. 271–
77.
P. Patchipulusu, “Dynamic Address Allocation Protocols for Mobile Ad Hoc Networks,” M.Sc. thesis, Comp. Sci., Texas A&M Univ.,
2001.
M. Mohsin and R. Prakash, “IP Address Assignment in a Mobile Ad Hoc Network,” Proc. MILCOM, vol. 2, Oct. 2002, pp. 856–61.
S.Zahoor ul Huq obtained B.Sc(Electronics) from Sri Krishna Devaraya Universty, Anantapur and
MCA from Osmania University, Hyderabad, India in the year 1997 and 2000 respectively. He also
obtained his M.E in Computer Science & Engineering from Anna University in 2004.He is currently
pursuing PhD degree from Sri Krishna Devaraya University, Anantapur, India,. He presented 6
research papers in various international journals. He is presently working as Associate Professor in
CSE Department, G. Pulla Reddy Engineering College, Kurnool, A.P, India.His research interests
include Computer Networks , Databases and data mining.
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Vol. 2(3), 2010, 227-231 Dr. K.E. Sreenivasa Murthy obtained B.Tech and M.Tech degrees in Electronics and
Communication Engineering from Sri Venkateswara University, Tirupati, India in 1989 and 1992
respectively and PhD degree from Sri Krishna Devaraya University, Anantapur, India, in 1997. He
presented more than 10 research papers in various national and international conferences and
journals. He is at present working as principal at G. Pullaiah College of Engineering and
Technology, Kurnool, India. His research interests include FPGA and DSP applications.
Dr. B. Sathyanarayana graduated from Madras Christian College, Madras University, Tamilnadu
India in1985 and post graduated from Madurai Kamaraju University, Tamilnadu in 1988 and
obtained PhD from Sri Krishna Devaraya University Ananthapur India in 2000. He Worked as
Head of the Departement in Department of Computer Science & Technology. Sri Krishna
Devaraya University Ananthapur ,Andhra Pradesh India He Published 11Papers for National and
International Journals. He attended for 3-National Conferences His area of interest is on Computer
Networks, Network Security and Image Processing.
D.Kavitha obatained her B.Tech degree from S.K.University, Anantapur and M.Tech degree
from Jawaharlal Nehru Technological University, Anantapur in the year 2001 and 2005
respectively.She is currently pursuing Ph.D at Sri Krishna Devaraya University, Anantapur, India.
She is presently working as Associate Professor in the Department of Computer Science and
Engineering at G. Pulla Reddy Engineering College, Kurnool, Andhra Pradesh, India. She
presented four research papers in national conferences, one in International Conference and one
research paper in International Journal.. Her research areas include Computer Networks and
Network Security
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