| 1. |
- Rohner, Christian, et al.
(author)
-
Interactions between TCP, UDP and Routing Protocols in Wireless Multi-hop Ad hoc Networks
- 2005
-
In: Proceedings of the 1st IEEE ICPS Workshop on Multi-hop Ad hoc Networks: from theory to reality (REALMAN 2005).
-
Conference paper (peer-reviewed)abstract
- The achieved throughput in an ad hoc network is affected by many factors, including radio interference between hops, the ability of the routing protocol to react on topology changes and a complex interaction between the application and underlying protocols. This paper studies experimentally the impact of these factors on UDP and TCP throughput. Furthermore, when both TCP and UDP share some hops in an ad hoc network there is a complex interaction between the transport protocols as well as with the routing protocol. Our results show that this interaction results in significant UDP jitter, instable routes and significantly lower TCP throughput. We use a controlled real testbed for the experiments and a graphical tool that captures the interactions.
|
|
| 2. |
- Achtzehn, Andreas, et al.
(author)
-
ARPD : Asynchronous random key predistribution in the LEAP framework for Wireless Sensor Networks
- 2007
-
In: 3rd IEEE International Workshop on Wireless and Sensor Networks Security (IEEE WSNS 2007).
-
Conference paper (peer-reviewed)abstract
- In the LEAP framework for wireless sensor networks a set of keys is used to secure communication. LEAP distinguishes between unicast (pairwise) communication, group (cluster) communication and global (broadcast) communication. The keys used in pairwise communication are derived from an initial key KI that nodes are equipped with prior to deployment and that is deleted after link setup. Further keys are distributed encrypted with these pairwise keys. If the initial key is ever disclosed, the whole network is compromised. To lower the threat of KI disclosure, we present a novel KI -less scheme for key predistribution. Our scheme is based on random key redistribution, and proves to perform better in medium sized networks than previous proposals. It is resilient against node capture attacks and allows node to node authentication. Attacks against overlying protocols in the network are more difficult with this scheme. We have conducted computations to show the feasibility of our scheme for networks up to a size of 1000 nodes. By introducing a key reuse system we are able to increase the probability of a successful link setup. We have included a security analysis that discusses our scheme’s resistance against commonly known attacks.
|
|
| 3. |
- Achtzehn, Andreas, et al.
(author)
-
Implementing Agreement Protocols in Sensor
- 2006
-
In: The Second International Workshop on Wireless and Sensor Networks Security (WSNS'06).
-
Conference paper (peer-reviewed)abstract
- We investigate application of agreement protocols tolerating malicious failures in sensor networks. We identify several scenarios where agreement can be used, and report on our experience with implementing an agreement protocol.
|
|
| 4. |
|
|
| 5. |
- Bastani, Saeed, et al.
(author)
-
A social node model for realising information dissemination strategies in delay tolerant networks
- 2012
-
In: Proceedings of the 15th ACM international conference on Modeling, analysis and simulation of wireless and mobile systems. - New york : ACM Press. ; , s. 79-88, s. 78-79
-
Conference paper (peer-reviewed)abstract
- In Delay Tolerant Networks (DTNs) as an emerging content dissemination platform, mobile nodes opportunistically exchange content as they meet, with the intent of disseminating content among nodes that share common interests. During a meeting, nodes can exchange both content of direct interest to themselves as well as content that is of interest to a larger set of nodes that may be encountered in the future. The utility of DTN is governed by the content exchange opportunity (the amount of content that can be exchanged during a meeting) as well as the selection of content to be exchanged in order to maximise the interest nodes will have in information they are exposed to. Considering that there is a cost associated with the content exchange (e.g. battery usage, buffer occupancy or consumed transmission opportunity) the aim for nodes participating in content dissemination should be to maximise their payoff. In this paper, we contribute a generic framework for describing the characteristics of content exchange among participating nodes in a network. We incorporate a distributed information popularity measurement and the pairwise interaction of nodes modelled as a bargaining problem. The outcome of this process is the fair split up of dwelling time as a network resource and the selection of which content objects to exchange in order to maximise the nodes’ payoff. The framework is generally intended to be used as a capstone for investigation of content dissemination properties and various content exchange strategies in a DTN, a topic addressed in this paper and experiments conducted to validate the function and correctness of the proposed framework.
|
|
| 6. |
- Beneson, Zinaida, et al.
(author)
-
Verifiable Agreement: Limits of Non-Repudiation in Mobile Peer-to-Peer Ad Hoc Networks
- 2006
-
In: Third European Workshop on Security and Privacy in Ad hoc and Sensor Networks.
-
Conference paper (peer-reviewed)abstract
- We introduce verifiable agreement as a fundamental service for securing mobile peer-to-peer ad hoc networks, and investigate its solvability. Verifiability of a protocol result means that the participants can prove that the protocol reached a particular result to any third party (the verifier) which was not present in the network at the time of the protocol execution.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Bjurefors, Fredrik
(author)
-
Measurements in opportunistic networks
- 2012
-
Licentiate thesis (other academic/artistic)abstract
- Opportunistic networks are a subset of delay tolerant networks where the contacts are unscheduled. Such networks can be formed ad hoc by wireless devices, such as mobile phones and laptops. In this work we use a data-centric architecture for opportunistic networks to evaluate data dissemination overhead, congestion in nodes' buffer, and the impact of transfer ordering. Dissemination brings an overhead since data is replicated to be spread in the network and overhead leads to congestion, i.e., overloaded buffers.We develop and implement an emulation testbed to experimentally evaluate properties of opportunistic networks. We evaluate the repeatability of experiments in the emulated testbed that is based on virtual computers. We show that the timing variations are on the order of milliseconds.The testbed was used to investigate overhead in data dissemination, congestion avoidance, and transfer ordering in opportunistic networks. We show that the overhead can be reduced by informing other nodes in the network about what data a node is carrying. Congestion avoidance was evaluated in terms of buffer management, since that is the available tool in an opportunistic network, to handle congestion. It was shown that replication information of data objects in the buffer yields the best results. We show that in a data-centric architecture were each data item is valued differently, transfer ordering is important to achieve delivery of the most valued data.
|
|
