Auto-Configuration Protocols in Mobile Ad Hoc Networks

The TCP/IP protocol allows the different nodes in a network to communicate by associating a different IP address to each node. In wired or wireless networks with infrastructure, we have a server or node acting as such which correctly assigns IP addresses, but in mobile ad hoc networks there is no such centralized entity capable of carrying out this function. Therefore, a protocol is needed to perform the network configuration automatically and in a dynamic way, which will use all nodes in the network (or part thereof) as if they were servers that manage IP addresses. This article reviews the major proposed auto-configuration protocols for mobile ad hoc networks, with particular emphasis on one of the most recent: D2HCP. This work also includes a comparison of auto-configuration protocols for mobile ad hoc networks by specifying the most relevant metrics, such as a guarantee of uniqueness, overhead, latency, dependency on the routing protocol and uniformity

E-D2HCP: enhanced distributed dynamic host configuration protocol

Mobile Ad Hoc Networks (MANETs) consist of mobile nodes equipped with wireless devices. They do not need any kind of pre-existent infrastructure and are about self-managed networks. MANETs enable communication between mobile nodes without direct links and across multihop paths. To ensure correct operation of the routing protocols, MANETs, have to assign unique IP addresses to the MANET devices. Furthermore, the address assignment is an important issue when dealing with MANET networks because the traditional approaches are not applicable without some changes, having to provide new protocols for the address auto-configuration. These schemes must take into account the properties of MANETs such as dynamic topology, limited resources or lack of infrastructure. In this paper, we propose a stateful scheme for dynamic allocation of IP addresses in MANETs entitled Extended Distributed Dynamic Host Configuration Protocol because it is based on a previous piece of work (D2CHP). This extension includes the network merging not covered by its predecessor. Simulation results show that the new protocol also improves D2HCP functionality in areas such as fault tolerance, concurrency and latency.Sección Deptal. de Sistemas Informáticos y ComputaciónFac. de Ciencias MatemáticasTRUEAgencia Espanola de Cooperacion Internacional para el Desarrollo (AECID, Spain) through Accion Integrada MAEC-AECID MEDITERRANEOSecurity Engineering Research Center - Ministry of Knowledge Economy (MKE, Korea)pu

Distributed Dynamic Host Configuration Protocol (D2HCP)

Mobile Ad Hoc Networks (MANETs) are multihop wireless networks of mobile nodes without any fixed or preexisting infrastructure. The topology of these networks can change randomly due to the unpredictable mobility of nodes and their propagation characteristics. In most networks, including MANETs, each node needs a unique identifier to communicate. This work presents a distributed protocol for dynamic node IP address assignment in MANETs. Nodes of a MANET synchronize from time to time to maintain a record of IP address assignments in the entire network and detect any IP address leaks. The proposed stateful autoconfiguration scheme uses the OLSR proactive routing protocol for synchronization and guarantees unique IP addresses under a variety of network conditions, including message losses and network partitioning. Simulation results show that the protocol incurs low latency and communication overhead for IP address assignment

Mobile Networking

We point out the different performance problems that need to be addressed when considering mobility in IP networks. We also define the reference architecture and present a framework to classify the different solutions for mobility management in IP networks. The performance of the major candidate micro-mobility solutions is evaluated for both real-time (UDP) and data (TCP) traffic through simulation and by means of an analytical model. Using these models we compare the performance of different mobility management schemes for different data and real-time services and the network resources that are needed for it. We point out the problems of TCP in wireless environments and review some proposed enhancements to TCP that aim at improving TCP performance. We make a detailed study of how some of micro-mobility protocols namely Cellular IP, Hawaii and Hierarchical Mobile IP affect the behavior of TCP and their interaction with the MAC layer. We investigate the impact of handoffs on TCP by means of simulation traces that show the evolution of segments and acknowledgments during handoffs.Publicad

Performance of IP address auto-configuration protocols in Delay and Disruptive Tolerant Networks

At this moment there is a lack of research respecting Mobile Ad-hoc Networks (MANET) address assignment methods used in Delay Tolerant Networks (DTN). The goal of this paper is to review the SDAD, WDAD and Buddy methods of IP address assignment known from MANET in difficult environment of Delay and Disruptive Tolerant Networks. Our research allows us for estimating the effectiveness of the chosen solution and, therefore, to choose the most suitable one for specified conditions. As a part of the work we have created a tool which allows to compare these methods in terms of capability of solving address conflicts and network load. Our simulator was created from scratch in Java programming language in such a manner, that implementation of new features and improvements in the future will be as convenient as possible

Modeling and Performance Evaluation of MANET Handover

A Mobile Ad Hoc Network (MANET) is an unstructured collection of wireless nodes that move arbitrarily and use multi-hop protocols to communicate between each other. There is not a predefined infrastructure in a MANET as there is in other types of wireless networks. Now days, MANET networks integrate with other networks, like the Internet, permitting ad hoc nodes to communicate with hosts placed in any part of the world. But the integration of MANETs with fixed infrastructures must be carefully studied to evaluate how it performs. In such integrated scenario, commonly known as Hybrid Ad Hoc Network, a MANET can be seen as an extension to the existing infrastructure, whose mobile nodes seamlessly communicate with hosts on the fixed network by forwarding packets throughout the gateways found on the edge that join both types of network. Connecting MANETs to the Internet does not come without difficulties. Ad hoc routing protocols work different than the regular routing protocols used on the Internet, and their interoperability becomes an important issue. But when MANETs integrate with the Internet, a more demanding challenge emerges if node mobility is considered. A moving node may lose registration with its current gateway, and may then need to register to a different gateway (a handover) to continue communicating. During a handover, any ongoing communication will be interrupted affecting network performance. In order to improve this performance, an IP mobility management protocol must be used. The main objective of this research is to develop a model that may be used to evaluate the performance of MANET handovers under different scenarios. Different issues about MANET integration with the Internet are considered: the IP mobility protocol implemented, the external route computation procedure, the type of ad hoc routing protocol used, and the gateway discovery approach used. For this evaluation, a mobile node in a MANET holding a communication with a correspondent node in the Internet roams to a different sub-network, having to change its registration to a different gateway. The different scenarios considered to evaluate the handover performance include the use of different types of MANET protocols, the use of different gateway discovery approaches, and the use of different versions of the Mobile IP protocol. During the research a review was made of the functioning conditions for the proposed scenario. Then, a handover model was proposed, which was used to develop some metrics that were later used to evaluate the MANET handover performance. This metrics are the broken communication time, the probability of handover failure, and the average communication interruption time. In all the results found, we could confirm that the proactive discovery approach has a better handover performance than the reactive discovery approach, which permit us to conclude that regardless the MANET routing protocol, and the Mobile IP version, the proactive agent discovery approach should be used in highly mobile scenarios, preferable, with the reactive routing protocol