Table of Contents
research papers
some a downloaded to /mydir/mywork/dai/docs
MANET
Wireless Ad Hoc Networks (2002)
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.13.8133&rep=rep1&type=pdf
Abstract: A mobile ad hoc network is a relatively new term for an old technology - a network that does not rely on pre-existing infrastructure. Roots of this technology could be traced back to the early 1970s with the DARPA PRNet and the SURAN projects. The new twitch is the application of this technology in the non-military communication environments. Additionally, the research community has also recently addressed some extended features of this technology, such as multicasting and security. Also numerous new solutions to the “old” problems of routing and medium access control have been proposed. This survey attempts to summarize the state-ofthe -art of the ad hoc networking technology in four areas: routing, medium access control, multicasting, and security. Where possible, comparison between the proposed protocols is also discussed.
DTN
DTN improvements
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Disruption-Tolerant Networking: A Comprehensive Survey on Recent Developments and Persisting Challenges
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5770277
Abstract: Nowadays, wireless networks are witnessing several deployments in various extreme environments where they suffer from different levels of link disruptions depending on the severity of the operating conditions. In all cases, their operation requirements are differently altered and their performance is negatively affected rendering them heterogeneous by nature. In the open literature, these networks are known as Intermittently Connected Networks (ICNs). The existing Internet protocols fail to operate properly in the context of ICNs, thus raising a variety of new challenging problems that are attracting the attention of the networking research community. Delay-/Disruption-Tolerant Networking emerged as a highly active area of research where networking experts compete in addressing the various ICN problems. Over time, unicast routing, one of the architectural key components common to all ICNs, became an almost independent field of research in which significant efforts continue to be invested. In contrast, network architectural designs, scheduling and forwarding issues dating from the early days of Inter-Planetary Networks (IPNs) have received relatively little attention and accumulate numerous pending challenges. Moreover, the gap caused by the lack of accurate ICN mathematical models is still large irrespective of some of the appreciated seminal works in this direction. This paper sheds the light over the latest advancements in each of the above-mentioned research sectors and highlight pending open issues in each of them.
Implementing Delay Tolerant Networking
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DTN overlay on OLSR network
abstract: Wireless Mobile Ad-hoc Networks (MANETs) are characterized by frequent and unpredictable disconnections, due to mobility, interference, power management or any other issues. Such disconnections result in the failure of MANET routing protocols that are designed to establish end-to-end paths between the communicating nodes.
This work focuses on enhancing the performance of MANETs by integrating MANET routing using Optimized Link State Routing (OLSR) and Delay Tolerant Networking (DTN) based store and forwarding. Further, we provide support for device heterogeneity by not requiring all the nodes in the network to be DTN capable. The non-DTN capable nodes can use the store and forward functionality of other DTN nodes in the network to combat the effect of network partitioning. We define a DTN-based OLSR, DTS-OLSR, with a new routing and discovery mechanism based on Structured Mesh Overlay Network (SMON) to fulfill the objectives.
As a proof of concept, we implement DTS-OLSR where it is demonstrated that our scheme is successful in dealing with the problem of network partitioning. Our architecture mainly targets networks that can tolerate delay but require high reliability such as an ad hoc network constructed in an emergency scenario.
Integrating DTN and MANET Routing
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.111.2299&rep=rep1&type=pdf
Abstract: Mobile Ad-hoc Network (MANET) routing protocols aim at estab- lishing end-to-end paths between communicating nodes and thus support end-to-end semantics of existing transports and applica- tions. In contrast, DTN-based communication schemes imply asyn- chronous communication (and thus often require new applications) but achieve better reachability, particularly in sparsely populated environments. In this paper, we suggest a hybrid scheme that com- bines AODV and DTN-based routing and allows keeping the AODV advantage of maintaining end-to-end semantics whenever possible while, at the same time, also offering DTN-based communication options whenever available—leaving the choice to the application. We present our protocol and system design, particularly including the interaction of AODV and DTN, demonstrate achievable perfor- mance gains based upon measurements, and report on initial exper- iments with our implementation in an emulation environment.
DTLSR: Delay Tolerant Routing for Developing Regions
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.132.4975&rep=rep1&type=pdf
ABSTRACT We consider the problem of routing in delay tolerant networks de- ployed in developing regions. Although these environments expe- rience intermittent connectivity (hence the desire to use DTN), in many cases the topology has an underlying stability that we can ex- ploit when designing routing protocols. By making small, yet crit- ical, modifications to classical link state routing, we derive a more effective algorithm capable of leveraging predictions of future link uptimes. We describe a complete and fully-implemented protocol, capable of being deployed in the DTN reference implementation without modification. Using a simulation incorporating real-world network characteristics, we demonstrate that our system operates effectively when conventional routing and forwarding may fail.
STAR: Storage aware routing protocol for generalized Delay Tolerant Networks
Abstract: This paper presents a novel storage aware routing (STAR) protocol designed to provide a general networking solution over a broad range of mobile and wireless scenarios. STAR enables routing policies which adapt seamlessly from a well-connected wired network to a disconnected wireless network using a 2-Dl routing metric composed of a short and a long term route cost and storage availability on downstream routers. Temporary in-network storage is preferred over forwarding along a path that is slower than average and opportunistic transmission is encouraged when a faster route becomes available. Results from ns2 based simulations show that STAR achieves 20% higher throughput compared to OLSR under varying link conditions and delivers 20% more files in DTN scenarios. Experimental evaluation of STAR on the ORBIT testbed demonstrates significant performance improvements with 25% higher peak throughput compared to OLSR in a wireless mesh network.
A field experience on DTN-based sensor data gathering in agricultural scenarios
Abstract: This paper describes our field experience on data collection from remote sensors. By letting tractors, farmers and sensors have short-range radio communication device with delay disruption tolerant networking (DTN), we can collect data from those remote sensors to our central database. Although, several implementations have been made by using PHS devices or mesh network in the past, DTN-based systems for such applications are still under explored. The main contribution of this paper is to present our practical implementation and experiences on DTN based data collection from remote sensors. The software, which we have developed for this research, is very small only about 3000 lines in C, which is much smaller than any other DTN implementations. We carried out an experiment with 10 DTN nodes in the University of Tokyo. They achieved 100% collection with moderate delivery latency showing sufficient usefulness in data granularity.
From Delay-Tolerant Networks to Vehicular Delay-Tolerant Networks
http://ieeexplore.ieee.org/iel5/9739/5451756/06007076.pdf?arnumber=6007076
Abstract: This paper provides an introductory overview of Vehicular Delay-Tolerant Networks. First, an introduction to Delay-Tolerant Networks and Vehicular Delay-Tolerant Networks is given. Delay-Tolerant schemes and protocols can help in situations where network connectivity is sparse or with large variations in density, or even when there is no end-to-end connectivity by providing a communications solution for non real- time applications. Some special issues like routing are addressed in the paper and an introductory description of applications and the most important projects is given. Finally, some research challenges are discussed and conclusions are detailed.
Routing
Dynamic source routing in ad hoc wireless networks (1996)
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.129.426&rep=rep1&type=pdf
Abstract: An ad hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration. In such an environment, it may be necessary for one mobile host to enlist the aid of other hosts in forwarding a packet to its destination, due to the limited range of each mobile host’s wireless transmissions. This paper presents a protocol for routing in ad hoc networks that uses dynamic source routing. The protocol adapts quickly to routing changes when host movement is frequent, yet requires little or no overhead during periods in which hosts move less frequently. Based on results from a packet-level simulation of mobile hosts operating in an ad hoc network, the protocol performs well over a variety of environmental conditions such as host density and movement rates. For all but the highest rates of host movement simulated, the overhead of the protocol is quite low, falling to just 1 % of total data packets transmitted for moderate movement rates in a network of 24 mobile hosts. In all cases, the difference in length between the routes used and the optimal route lengths is negligible, and in most cases, route lengths are on average within a factor of 1.01 of optimal. 1.
DTN routing as a resource allocation problem (2007)
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.129.9966&rep=rep1&type=pdf
Abstract: Routing protocols for disruption-tolerant networks (DTNs) use a variety of mechanisms, including discovering the meeting probabilities among nodes, packet replication, and network coding. The primary focus of these mechanisms is to increase the likelihood of finding a path with limited information, and so these approaches have only an incidental effect on routing such metrics as maximum or average delivery delay. In this paper, we present rapid, an intentional DTN routing protocol that can optimize a specific routing metric such as the worst-case delivery delay or the fraction of packets that are delivered within a deadline. The key insight is to treat DTN routing as a resource allocation problem that translates the routing metric into per-packet utilities which determine how packets should be replicated in the system. We evaluate rapid rigorously through a prototype deployed over a vehicular DTN testbed of 40 buses and simulations based on real traces. To our knowledge, this is the first paper to report on a routing protocol deployed on a real DTN at this scale. Our results suggest that rapid significantly outperforms existing routing protocols for several metrics. We also show empirically that for small loads RAPID is within 10 % of the optimal performance.
An Ad Hoc Cooperative Routing Algorithm Based on Symmetric Link Selection
A MAC layer protocol for wireless networks with asymmetric links
http://www.sciencedirect.com/science/article/pii/S1570870507000510
Abstract: We introduce AsyMAC, a MAC layer protocol for wireless networks with asymmetric links and study a protocol stack consisting of AsyMAC and the A4LP routing protocol. The two protocols are able to maintain connectivity where the standard IEEE 802.11 MAC protocol coupled with either AODV or OLSR routing protocols may loose connectivity. A comparative study shows that AsyMAC improves on two previously proposed protocols’ accuracy in determining the nodes to be silenced to prevent collisions.
