Dan Galatchi

Analysis and simulation of a Predictable Routing Protocol for VANETs

Vehicular ad hoc networks (VANETs) are expected to support a large spectrum of mobile distributed applications ranging from traffic alert dissemination and dynamic route planning to context-aware advertisement and file sharing. Internetworking over VANETs becomes one of the most important applications and desired service for mobile users. In current ad-hoc routing protocols, the control messages in reactive protocols and route update timers in proactive protocols are not used to anticipate link breakage. They only indicate presence or absence of a route to a given node. Consequently, the route maintenance process at both protocol types is initiated only after a link breakage event takes place. This paper analysis the possibility to predict a link breakage event prior to its occurrence. Vehicles are grouped according to their velocity vectors. When a vehicle shifts to a different group and a route, involving the vehicle, is to be broken, the protocol searches for a more stable route that includes vehicles from the same group. Whilst this scheme (Predictable Routing Protocol - PRP) can be implemented on any existing routing protocol, the paper considers the case of PRP over Destination-Sequenced Distance Vector (DSDV) routing protocol and Optimized Link State Routing (OLSR) protocol. The performance of the scheme is evaluated through computer simulations.

Lane departure warning system implementation using the Blackfin microcomputer

the purpose of this paper is to evaluate the performance of an embedded lane departure monitoring system implemented using the Blackfin microcomputer. This paper is focused on evaluating the image processing algorithm and the main goal of this work is to propose methods to speed-up the necessary computations. A practical, flexible and low cost solution is proposed and the monitoring system is effective at medium vehicle speeds.

Flat routing protocols for ad hoc mobile wireless networks

Ad hoc networks are characterized by multihop wireless connectivity, frequently changing network topology and the need for efficient dynamic routing protocols plays an important role. In these networks there is no fixed topology due to the mobility of nodes, interference, multipath propagation and path loss. Hence a dynamic routing protocol is needed for these networks to function properly. Many of them have been developed for accomplishing this task. This paper presents two mobile ad-hoc routing protocols DSDV and AODV where the first one is a proactive protocol depending on routing tables which are maintained at each node. The other one is a reactive protocol, which finds a route to a destination on demand, whenever communication is needed.

Improved load balancing and scheduling performance in embedded systems with task migration

This paper presents a migration mechanism for tasks running in nodes of a wireless sensor network (WSN). The WSN is consisted of digital signal processing nodes implemented with Blackfin microcomputers with Micrium μC OS III operating system. The migration mechanism allows load balancing, better scheduling of the tasks and allow cooperative signal processing at the whole network and it is useful in case of the node failures as well. This mechanism uses the Micrium operating system primitives in order to decide when the task migration will be started and to control the whole migration process. The communication network is provided by Lightweight Internet Protocol (LwIP) protocol. A performance evaluation (load balance, migration time and missed deadlines ratio) is performed. The paper demonstrates viable implementation of tasks migration in embedded systems and illustrates a better performance of the load balancing and the tasks scheduling.

Embedded content aware router implementation using the Blackfin microcomputer

The purpose of this paper is to evaluate the performance of embedded content aware routers implemented using the Blackfin microcomputer. The main goal of this work is to propose methods to speed-up the necessary computations in the content aware routers. A practical solution is proposed.

Analysis of a traffic flow optimization protocol for hybrid MANETs

The communication between wireless ad-hoc networks and infrastructure-based networks is essential to extend Internet beyond its traditional scope, to remote inaccessible areas, making Web services in ad-hoc networks available anytime, anywhere. The mobile nodes in a wireless ad-hoc network must be able to detect available gateways and select one of them if they want to have Internet access. In this paper, the analyzed protocol proposes the transfer of the mobile gateway functionality to another node present in the covered area of the access point acting as a router. There were evaluated the following performances of the proposed protocol (using OPNET): packet delivery ratio, overhead and the packet delay.