2,027 research outputs found
Approximation Algorithms for Multi-Point Relay Selection in Mobile Wireless Networks
Routing is one of the main problems for Mobile Wireless Networks. In the case of infrastructureless multihop wireless networks, the selection of Multi-Point Relays provides efficient routing schemes. As such a selection is NP-hard, an efficient heuristic has been designed and effectively implemented in protocols for Mobile Ad Hoc Networks such as the Optimized Link State Routing protocol (OLSR). In this paper, we introduce two variants of this practical heuristic by exploiting the topological properties of the network (without assuming a knowledge of geographic positions or geometric properties). For each heuristic, we give their respective guaranteed approximation performances when compared to a solution of optimal value. We argue that the heuristics proposed are of considerable interest when other problems are considered in addition to the routing efficiency (e.g., minimum remaining bandwidth, minimum remaining energy,...)
Multihop Routing in Ad Hoc Networks
This paper presents a dual method of closed-form analysis and lightweight
simulation that enables an evaluation of the performance of mobile ad hoc
networks that is more realistic, efficient, and accurate than those found in
existing publications. Some features accommodated by the new analysis are
shadowing, exclusion and guard zones, and distance-dependent fading. Three
routing protocols are examined: least-delay, nearest-neighbor, and
maximum-progress routing. The tradeoffs among the path reliabilities, average
conditional delays, average conditional number of hops, and area spectral
efficiencies are examined.Comment: 6 pages, 6 figures, to appear in IEEE Military Commun. Conf.
(MILCOM), 201
Experimentation with MANETs of Smartphones
Mobile AdHoc NETworks (MANETs) have been identified as a key emerging
technology for scenarios in which IEEE 802.11 or cellular communications are
either infeasible, inefficient, or cost-ineffective. Smartphones are the most
adequate network nodes in many of these scenarios, but it is not
straightforward to build a network with them. We extensively survey existing
possibilities to build applications on top of ad-hoc smartphone networks for
experimentation purposes, and introduce a taxonomy to classify them. We present
AdHocDroid, an Android package that creates an IP-level MANET of (rooted)
Android smartphones, and make it publicly available to the community.
AdHocDroid supports standard TCP/IP applications, providing real smartphone
IEEE 802.11 MANET and the capability to easily change the routing protocol. We
tested our framework on several smartphones and a laptop. We validate the MANET
running off-the-shelf applications, and reporting on experimental performance
evaluation, including network metrics and battery discharge rate.Comment: 6 pages, 7 figures, 1 tabl
Low Power, Low Delay: Opportunistic Routing meets Duty Cycling
Traditionally, routing in wireless sensor networks consists of
two steps: First, the routing protocol selects a next hop,
and, second, the MAC protocol waits for the intended destination
to wake up and receive the data. This design makes
it difficult to adapt to link dynamics and introduces delays
while waiting for the next hop to wake up.
In this paper we introduce ORW, a practical opportunistic
routing scheme for wireless sensor networks. In a dutycycled
setting, packets are addressed to sets of potential receivers
and forwarded by the neighbor that wakes up first
and successfully receives the packet. This reduces delay and
energy consumption by utilizing all neighbors as potential
forwarders. Furthermore, this increases resilience to wireless
link dynamics by exploiting spatial diversity. Our results
show that ORW reduces radio duty-cycles on average
by 50% (up to 90% on individual nodes) and delays by 30%
to 90% when compared to the state of the art
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