Name services for mobile ad hoc networks are essential to discover and bind resources given by their name or URI to a specific network address. As there is no fixed infrastructure available in MANETs, nodes cannot rely on any DNS-like system as is taken for granted in the Internet. To keep up with the dynamicity of MANETs, a name service needs to be flexible and scalable. For this purpose, we propose MAPNaS (mobile ad-hoc peer-to-peer name service), a lightweight and locality-aware peer-to-peer based name service. MAPNaS runs on top of MADPastry (T. Zhan and J. Schiller, June 2005), a general-purpose DHT substrate especially designed for MANETs. Through simulation we compare the performance of MAPNaS - both in terms of the success rate and overall network traffic - against an unstructured, broadcast-based reference approach. We thereby demonstrate how to efficiently build a peer-to-peer based name service in mobile ad hoc networks
In the natural sciences, researchers use a variety of techniques that rely on extensive man-hours and can therefore be difficult to scale. This obviously limits questions that concern large spatial scales or that involve large numbers of animals. Here, we describe the design and deployment of a wireless sensor network that delivers high resolution sensor data while monitoring seabirds on a UK National Nature Reserve. We describe some of the problems encountered and the solutions we have used. In general, the network has successfully demonstrated its utility in a real world scenario and will be extended and enhanced for the coming field season.
A major step towards secure Internet backbone routing started with the deployment of the Resource Public Key Infrastructure (RPKI). It allows for the cryptographic strong binding of an IP prefix and autonomous systems that are legitimate to originate this prefix. A fundamental design choice of RPKI-based prefix origin validation is the avoidance of cryptographic load at BGP routers. Cryptographic verifications will be performed only by cache servers, which deliver valid AS/prefix mappings to the RPKI-enabled BGP router using the RPKI/RTR protocol. In this paper, we give first insights into the additional system load introduced by RPKI at BGP routers. For this purpose, we design and implement a highly efficient C library of the RPKI/RTR router part and the prefix origin validation scheme. It fetches and stores validated prefix origin data from an RTR-cache and performs origin verification of prefixes as obtained from BGP updates. We measure a relatively small overhead of origin validation on commodity hardware (5% more RAM than required for full BGP table support, 0.41% load in case of ≈ 92,000 prefix updates per minute), which meets realworld requirements of today.
If the WSN is located in an outdoor environment, standard solutions like GPS can be applied. If GPS is not available it is possible to measure the radio propagation properties beforehand or install beacons on known positions to allow a WSN node to determine its position. In our scenario we suffer from the problem that we do not have any a priori information about the environment, as we want to localize WSN nodes within an ad hoc network. Known solutions without special hardware support usually exploit the received signal strength indicator (RSSI) to approximate the distance to an anchor node. In several publications and own experiments the RSSI based approach performed very bad concerning accuracy in unknown environments [6].
