Ad hoc wireless distribution service

About: Ad hoc wireless distribution service is a research topic. Over the lifetime, 17734 publications have been published within this topic receiving 488205 citations.

Mobile ad hoc extensions for the internet

Abstract: Described is an internetworking system having various mobile ad hoc extensions to the Internet that are particularly suited to the dynamic environment of mobile ad hoc networks. The internetworking system includes any combination of a link-state routing protocol for disseminating topology and link-state information over a multi-hop network comprised of nodes, a neighbor discovery protocol that can detect the appearance and disappearance of new neighbor nodes, an address format that facilitates deployment of IPv6 nodes in a predominantly IPv4 network infrastructure, a queuing mechanism that can update information upon resuming interrupted communications between nodes, and dynamic network measurement techniques for adaptively using wireless bandwidth when establishing and maintaining connections between nodes and a server.

SOAR: Simple Opportunistic Adaptive Routing Protocol for Wireless Mesh Networks

Abstract: Multihop wireless mesh networks are becoming a new attractive communication paradigm owing to their low cost and ease of deployment. Routing protocols are critical to the performance and reliability of wireless mesh networks. Traditional routing protocols send traffic along predetermined paths and face difficulties in coping with unreliable and unpredictable wireless medium. In this paper, we propose a simple opportunistic adaptive routing protocol (SOAR) to explicitly support multiple simultaneous flows in wireless mesh networks. SOAR incorporates the following four major components to achieve high throughput and fairness: 1) adaptive forwarding path selection to leverage path diversity while minimizing duplicate transmissions, 2) priority timer-based forwarding to let only the best forwarding node forward the packet, 3) local loss recovery to efficiently detect and retransmit lost packets, and 4) adaptive rate control to determine an appropriate sending rate according to the current network conditions. We implement SOAR in both NS-2 simulation and an 18-node wireless mesh testbed. Our extensive evaluation shows that SOAR significantly outperforms traditional routing and a seminal opportunistic routing protocol, ExOR, under a wide range of scenarios.

Denial of service resilience in ad hoc networks

Abstract: Significant progress has been made towards making ad hoc networks secure and DoS resilient. However, little attention has been focused on quantifying DoS resilience: Do ad hoc networks have sufficiently redundant paths and counter-DoS mechanisms to make DoS attacks largely ineffective? Or are there attack and system factors that can lead to devastating effects? In this paper, we design and study DoS attacks in order to assess the damage that difficult-to-detect attackers can cause. The first attack we study, called the JellyFish attack, is targeted against closed-loop flows such as TCP; although protocol compliant, it has devastating effects. The second is the Black Hole attack, which has effects similar to the JellyFish, but on open-loop flows. We quantify via simulations and analytical modeling the scalability of DoS attacks as a function of key performance parameters such as mobility, system size, node density, and counter-DoS strategy. One perhaps surprising result is that such DoS attacks can increase the capacity of ad hoc networks, as they starve multi-hop flows and only allow one-hop communication, a capacity-maximizing, yet clearly undesirable situation.

Weak duplicate address detection in mobile ad hoc networks

Abstract: Auto-configuration is a desirable goal in implementing mobile ad hoc networks. Specifically, automated dynamic assignment (without manual intervention) of IP addresses is desirable. In traditional networks, such dynamic address assignment is often performed using the Dynamic Host Configuration Protocol (DHCP). Implementing DHCP, however, requires access to a DHCP server. In mobile ad hoc networks, it is difficult to guarantee access to a DHCP server, since ad hoc networks can become partitioned due to host mobility. Therefore, alternative mechanisms must be employed. One plausible approach is to allow a node to pick a tentative address randomly (or using some locally available information), and then use a "duplicate address detection" (DAD) procedure to detect duplicate addresses. The previously proposed DAD procedures make use of timeouts and do not always perform correctly in presence of partitions. In networks where message delays cannot be bounded, use of timeouts can lead to unreliability. Therefore, we propose an alternative approach (which can be used in conjunction with previously proposed schemes). We refer to the proposed approach as "weak" duplicate address detection. The goal of weak DAD is to prevent a packet from being routed to the "wrong" destination node, even if two nodes in the network happen to have chosen the same IP address. We also propose an enhanced version of the weak DAD scheme, which removes a potential shortcoming of the weak DAD approach.