Address Auto-configuration in
Mobile Ad Hoc Networks Current
Approaches and Future Directions
Date：2005 / 1 / 20
Speaker：Xu Jia-Hao
Advisor：Ke Kai-Wei
Outline
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Introduction
Stateful protocols
Stateless protocols
Hybrid approaches
Conclusion
Reference
Introduction
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Mobile ad hoc networks are infrastructureless
self-organizing wireless networks.
Before proper routing of data packets in a
network is possible, all nodes need to be
configured with unique addresses.
Preconfiguration is not always possible, so
that, an autoconfiguration protocol is required.
Introduction (Cont.)
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The main task of an address autoconfiguration
protocol is to manage the resource address
space.
Allocate a unique address to an unconfigured
node and deallocate when it leaving the
network.
A major challenge is network partitioning and
merging.
Introduction (Cont.)
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All nodes need to confirm their own address
is uniqueness within a single network
partition.
Autoconfiguration protocols for conventional
networks can be classified in protocols
utilizing either stateless or stateful
approaches.
Stateful Approach
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Assume the existence of a central entity to
assign unique addresses to unconfigured
nodes and to keep state information about
already assigned addresses in an address
allocation table.
An example is DHCP (Dynamic Host
Configuration Protocol).
Stateless Approach
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Allow the nodes to select an address by
themselves and verify its uniqueness in a
distributed manner with the so-called
duplicated address detection (DAD).
The DAD is performed by broadcasting a
special ARP probe for the selected address.
Outline
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Introduction
Stateful protocols
Stateless protocols
Hybrid approaches
Conclusion
Reference
Stateful protocols
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That can be classified according to the way
they maintain the address allocation table.
Three major approaches：
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Centralized maintenance of the allocation table.
Distributed maintenance of a common allocation
table.
Distributed maintenance of multiple disjoint
allocation tables.
Selects and assigns an address as the
initiator and the node that requests and
address as the requester.
Centralized maintenance of the allocation
table
Distributed maintenance of a common
allocation table
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There are three protocols using distributed
common allocation table：
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MANETconf
Boleng’s protocol
Prophet allocation protocol
MANETconf
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Join node j (the requester)：
j send neighbor_query
if no reply is received
assign an address to itself
else
initiator flood an initiator_request contain address
if the address isn’t be used
reply initiator_response to the initiator (so and others)
else (negative reply)
repeat the allocation process with another address
initiator flood address_announce to every node
Distributed maintenance of a common
allocation table (Cont.)
Distributed maintenance of multiple
disjoint allocation tables
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The basic idea is to split the allocation table
among all nodes and use buddy systems for
efficient table mergers.
The initiator assigns half of its allocation table
to the requester and the new node itself can
autonomously assign addresses.
Distributed maintenance of multiple
disjoint allocation tables (Cont.)
Outline
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Introduction
Stateful protocols
Stateless protocols
Hybrid approaches
Conclusion
Reference
Stateless Approaches
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They do not maintain any allocation table.
Instead, an unconfigured node self-assigns
an address chosen randomly or based on a
hardware ID.
The uniqueness of the address is verified by
a DAD procedure after a network merger or
permanently performed.
Stateless Approaches (Cont.)
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There are three major approaches：
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Query-based DAD
-- To query all nodes
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Weak DAD
-- Address & Key
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Passive DAD
-- Based on protocol events
Outline
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Introduction
Stateful protocols
Stateless protocols
Hybrid approaches
Conclusion
Reference
Hybrid Approaches
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Hybrid protocols combine elements of both
stateful and stateless approaches.
There are two kinds of protocols：
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HCQA ( Hybrid Centralized Query-Based
Autoconfiguration )
PACMAN ( Passive Autoconfiguration for Mobile
Ad Hoc Networks )
HCQA
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It utilizes QDAD together with a centrally
maintained allocation table.
A node selects an address by itself and
verifies its uniqueness with the QDAD.
If the DAD is successful, it configures the
address and registers with a dynamically
elected address authority (AA), which inserts
the new address in its allocation table.
PACMAN
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It combines PDAD with a distributed
maintenance of a common allocation table.
The nodes passively collect information about
already assigned addresses in the network
from routing protocol traffic.
Outline
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Introduction
Stateful protocols
Stateless protocols
Hybrid approaches
Conclusion
Reference
Conclusion
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A centrally maintained allocation table has
fewer problems with inconsistent states, but
requires a dynamic leader election algorithm.
The most important component of stateless
approaches is DAD.
Reference
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Address Auto-configuration in Mobile Ad Hoc
Networks: Current Approaches and Future
Directions, IEEE Network Magazine, K.
Weniger, M. Zitterbart, Vol 18, No. 4, pp. 6-11,
2004.
Problem of partition merged
Address
conflicts
The resolution of a conflict requires at least one node to acquire a new address