Blacklist-aided forwarding in static multihop wireless networks

Proceedings of the 3rd ACM international symposium on Mobile ad hoc networking & computing - MobiHoc '02, 2002

We examine two aspects concerning the influence of unidirectional links on routing performance in multihop wireless networks. In the first part of the paper, we evaluate the benefit from utilizing unidirectional links for routing, as opposed to using only bidirectional links. Our evaluations are based on three transmit power assignment models that reflect some realistic network scenarios with unidirectional links. Our results indicate that the marginal benefit of using a high-overhead routing protocol to utilize unidirectional links is questionable. Most common routing protocols, however, simply assume that all network links are bidirectional, and thus may need additional protocol actions to remove unidirectional links from route computations. In the second part of the paper, we investigate this issue using a well known on-demand routing protocol, Ad hoc Ondemand Distance Vector (AODV), as a case study. We study the performance of three techniques for AODV for efficient operation in presence of unidirectional links, viz., BlackListing, Hello, and ReversePathSearch. While BlackListing and Hello techniques explicitly eliminate unidirectional links, the ReversePathSearch technique exploits the greater network connectivity offered by the existence of multiple paths between nodes. Performance results using ns-2 simulations, under varying number of unidirectional links and node speeds, show that all three techniques improve performance by avoiding unidirectional links, the ReversePathSearch technique being the most effective.

2010 First IEEE International Conference on Smart Grid Communications, 2010

Unreliable wireless links can cause frequent link (and route) failures, creating a major challenge for routing protocols who need to constantly repair routes and find alternate paths. In this paper we propose DADR (Distributed Autonomous Depth-first Routing), a new distributed distance-vector routing protocol designed to adapt quickly to changing link conditions while minimizing network control overhead. In our algorithm, when a link fails, data packets are rerouted through an alternate next hop, and the information about the failed link is propagated with the data packet; therefore, routes are updated dynamically and with little overhead. We have implemented DADR on several link-layer technologies and deployed it in different applications, including AMI deployments in Japan [1]; all implementations resulted in reliable networks that were easy to set up, maintain, and resilient to changing conditions. I.

Wireless Personal Communications, 2006

A mobile ad hoc network (MANET) is characterized by multi-hop wireless links and frequent node mobility. Communication between non-neighboring nodes requires a multi-hop routing protocol to establish a route. But, the route often breaks due to mobility. The source must rediscover a new route for delivering the data packets. This wastes the resources that are limited in MANET. In this paper, a new on-demand routing protocol is proposed, named on-demand routing protocol with backtracking (ORB), for multi-hop mobile ad hoc networks. We use the multiple routes and cache data technique to reduce the rediscovery times and overhead. After executing the route discovery phase, we find out a set of nodes, named checkpoint, which has the multiple routes to the destination. When a checkpoint node receives a data packet, it caches this data packet in its buffer within a specific time period. When a node detects a broken route during the data packets delivery or receives an error packet, it will either recover the broken route or reply the error packet to the source. If a node can not forward the data packet to the next node, it replies an error packet to the source. This packet is backtracking to search a checkpoint to redeliver the data packet to the destination along other alternate routes. The main advantage of ORB is to reduce the flooding search times, maybe just delay and cost while a route has broken. The experimental results show that the proposed scheme can increase the performance of delivery but reduce the overhead efficiently comparing with that of AODV based routing protocols.

IFIP International Federation for Information Processing, 2006

Computer Communications, 2007

7 8 Abstract 9

Mathematical Problems in Engineering, 2014

To keep information recent between two nodes, two types of link sensing feed-back mechanisms are used; Link Layer (LL) and Network Layer (NL). In this paper, we model and evaluate these link sensing mechanisms in three widely used reactive routing protocols; Ad-hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR) and DYnamic MANET On-demand (DYMO). Total cost paid by a routing protocol is the sum of cost paid in the form of energy consumed (in terms of packet reception/transmission) and time spent (in terms of processing route information). Routing operations are divided into two phases; Route Discovery (RD) and Route Maintenance (RM). These protocols majorly focuss on broadcast cost optimization performed by Expanding Ring Search (ERS) algorithm to control blind flooding. Hence, our model relates link sensing mechanisms in RD and RM for the September 10, 2014 DRAFT Recent research mainly focusses on Wireless Multi-hop Networks (WMhNs) due to increased use of wireless devices all around. A mobile node, in WMhNs, acts as a transmitter and as a router (relay node) for nodes not in the direct transmission range of each other. Applications of these networks range from a small room to large areas like, a battlefield or a natural disaster.

Computer Communications, 2012

Recently, routing protocols for mobile ad hoc networks (MANETs), which use position information to improve their efficiency, have been actively studied. In this paper, we develop a mathematical model to evaluate the performance of the beaconless routing algorithm (BLR). We also propose a new forwarding strategy named distance-aware forwarding (DAF) and compare the performance of DAF with that of the traditional strategy referred to as most forwarding within radius (MFR). BLR can efficiently reduce redundancy in its transmissions for flooding. When a node receives a packet, a time variable referred to as deferring time is calculated using the positions of the sender, receiver, and final destination of the packet. Each node forwards the packet after this deferring time unless it notices that another node forwards the same packet during the deferring time. As a result, only the node that is assigned the shortest deferring time forwards the packet. It is important to make this deferring time as short as possible to reduce the total deferring time in a multi-hop transmission. Numerical results demonstrate that the proposed strategy reduces the total deferring time in a multihop transmission, although the number of hops slightly increases. We also make a performance analysis considering packet collisions and suggest an implementation guideline of the transmission range.

A novel routing protocol for wireless, mobile ad hoc networks is presented. This protocol incorporates features that enhance routing reliability, defined as the ability to provide almost 100% packet delivery rate. The protocol is based on a virtual structure, unrelated to the physical network topology, where mobile nodes are connected by virtual links and are responsible for keeping physical routes to their neighbors in the virtual structure. Routes between pairs of mobiles are set up by using information to translate virtual paths discovered in the virtual structure. Route discovery and maintenance are based on unicast messages travelling across virtual paths, with sporadic use of flooding protocol. Most floodings are executed in background using low priority messages. The routing protocol has been evaluated and compared with the Dynamic Source Routing protocol (DSR) by means of simulation.

Wireless Networks, 2010

Communication networks, whether they are wired or wireless, have traditionally been assumed to be connected at least most of the time. However, emerging applications such as emergency response, special operations, smart environments, VANETs, etc. coupled with node heterogeneity and volatile links (e.g. due to wireless propagation phenomena and node mobility) will likely change the typical conditions under which networks operate. In fact, in such scenarios, networks may be mostly disconnected, i.e., most of the time, end-to-end paths connecting every node pair do not exist. To cope with frequent, long-lived disconnections, opportunistic routing techniques have been proposed in which, at every hop, a node decides whether it should forward or store-andcarry a message. Despite a growing number of such proposals, there still exists little consensus on the most suitable routing algorithm(s) in this context. One of the reasons is the large diversity of emerging wireless applications and networks exhibiting such "episodic" connectivity. These networks often have very different characteristics and requirements, making it very difficult, if not impossible, to design a routing solution that fits all. In this paper, we first break up existing routing strategies into a small number of common and tunable routing modules (e.g. message replication, coding, etc.), and then show how and when a given routing module should be used, depending on the set of network characteristics exhibited by the wireless application. We further attempt to create a taxonomy for intermittently connected networks. We try to identify generic network characteristics that are relevant to the routing process (e.g., network density, node heterogeneity, mobility patterns) and dissect different "challenged" wireless networks or applications based on these characteristics. Our goal is to identify a set of useful design guidelines that will enable one to choose an appropriate routing protocol for the application or network in hand. Finally, to demonstrate the utility of our approach, we take up some case studies of challenged wireless networks, and validate some of our routing design principles using simulations.

Lecture Notes in Computer Science, 2003

Ad hoc networking is a new paradigm of wireless communications for mobile nodes. Mobile ad hoc networks work properly only if the partecipating nodes cooperate to network protocols. Cooperative algorithms make the system vulnerable to user misbehavior as well as to malicious and selfish misbehavior. Nodes act selfishly to save battery power, by not cooperating to routing-forwarding functions. Lack of cooperation may severely degrade the performance of the ad hoc system. This paper presents a new approach to cope with cooperation misbehavior, focusing on the forwarding function. We present a general framework, based on reliability indices taking into account not only selfish/malicious misbehavior, but also situations of congestion and jammed links. We aim at avoiding unreliable routes and enforcing cooperation, thus increasing network "performability" (performance and reliability).