scholarly journals Trading Optimality for Scalability in Large-Scale Opportunistic Routing

2013 ◽  
Vol 62 (5) ◽  
pp. 2253-2263 ◽  
Author(s):  
Yanhua Li ◽  
Abedelaziz Mohaisen ◽  
Zhi-Li Zhang

Opportunistic routing utilizes the broadcast nature of wireless networks, significantly promoting the unicast throughput. Many variations of opportunistic routing designs have been proposed, although all of the current designs consistently rely on all of the topology information to construct forwarder lists and process data forwarding, which indeed restricts the application in large-scale wireless networks, where collecting global optimal information is very costly. In this paper, we propose the localized opportunistic routing (LOR) protocol, which utilizes the distributed minimum transmission selection (MTS-B) algorithm to partition the topology into several nested close-node-sets (CNSs) using local information. LOR can locally realize the optimal opportunistic routing for a large-scale wireless network with low control overhead cost. Since it does not use global topology information, LOR highlights an interesting tradeoff between the global optimality of the used forwarder lists and scalability inferred from the incurred overhead. Extensive simulation results show that LOR dramatically improves performances over extremely opportunistic routing (ExOR) and MAC-independent opportunistic routing protocol (MORE), which are two well-known designs from the literature, in terms of control overhead, end-to-end delay, and throughputs. It also exhibits promising performance in vehicular ad hoc networks (VANETs).

Author(s):  
Raúl Aquino-Santos ◽  
Víctor Rangel-Licea ◽  
Miguel A. García-Ruiz ◽  
Apolinar González-Potes ◽  
Omar Álvarez-Cardenas ◽  
...  

This chapter proposes a new routing algorithm that allows communication in vehicular ad hoc networks. In vehicular ad hoc networks, the transmitter node cannot determine the immediate future position of the receiving node beforehand. Furthermore, rapid topological changes and limited bandwidth compound the difficulties nodes experience when attempting to exchange position information. The authors first validate their algorithm in a small-scale network with test bed results. Then, for large-scale networks, they compare their protocol with the models of two prominent reactive routing algorithms: Ad-Hoc On-Demand Distance Vector and Dynamic Source Routing on a multi-lane circular dual motorway, representative of motorway driving. Then the authors compare their algorithm with motorway vehicular mobility, a location-based routing algorithm, on a multi-lane circular motorway. This chapter then provides motorway vehicular mobility results of a microscopic traffic model developed in OPNET, which the authors use to evaluate the performance of each protocol in terms of: Route Discovery Time, End to End Delay, Routing Overhead, Overhead, Routing Load, and Delivery Ratio.


Author(s):  
Amina Bengag ◽  
Asmae Bengag ◽  
Mohamed Elboukhari

In the recent years, the study and developments of networks that do not depend on any pre-existing infrastructure have been very popular. Vehicular Ad Hoc Networks (VANETs) belong to the class of these networks, in which each vehicle participates in routing by transmitting data for other nodes (vehicles). Due to the characteristics of VANET (e.g. high dynamic topology, different communication environment, frequently link breakage…), the routing process still one of the most challenging aspects. Hence, many routing protocols have been suggested to overcome these challenges. Moreover, routing protocols based on the position of vehicles are the most popular and preferred class, thanks to its many advantages like the less control overhead and the scalability. However, this class suffer from some problems such as frequent link breakages caused by the high-mobility of vehicles, which cause a low PDR and throughput. In this investigation, we introduce a novel greedy forwarding strategy used to create a new routing protocol based on the position of vehicles, to reduce the link breakages and get a stable route that improves the PDR and throughput. The proposed Density and Velocity (Speed, Direction) Aware Greedy Perimeter Stateless Routing protocol (DVA-GPSR) is based on the suggested greedy forwarding technique that utilizes the density, the speed and the direction for selecting the most convenient relaying node candidate. The results of simulation prove that DVA-GPSR protocol outperforms the classical GPSR in all studied metrics like PDR, throughput, and the ratio of routing overhead by changing the quantity of vehicles in urban and highway scenarios.


Author(s):  
Rajendra V. Boppana ◽  
Suresh Chalasani

Multihop wireless networks based on WiFi technology offer flexible and inexpensive networking possibilities. Applications of multihop wireless networks range from personal networks within consumer homes to citywide departmental networks to wide-area vehicular ad hoc networks. In this chapter, we focus on multihop ad hoc networks with communication among user devices and access points, where available, without the restriction that the user devices need to be within the radio range of access points. We first describe pure WiFi networks and their limitations. Next we discuss mixed networks based on WiFi and other wired and wireless technologies to provide robust city-scale networks. This chapter also explores security issues and vulnerabilities of wireless networks. An emerging application of WiFi ad hoc networks-RFID (radio frequency identification) networks based on the WiFi technology for warehouses and large retail stores-is presented. This chapter also presents another emerging application of WiFi-based networks: vehicular ad hoc networks for automobiles.


2011 ◽  
pp. 155-174
Author(s):  
Rajendra V. Boppana ◽  
Suresh Chalasani

Multihop wireless networks based on WiFi technology offer flexible and inexpensive networking possibilities. Applications of multihop wireless networks range from personal networks within consumer homes to citywide departmental networks to wide-area vehicular ad hoc networks. In this chapter, we focus on multihop ad hoc networks with communication among user devices and access points, where available, without the restriction that the user devices need to be within the radio range of access points. We first describe pure WiFi networks and their limitations. Next we discuss mixed networks based on WiFi and other wired and wireless technologies to provide robust city-scale networks. This chapter also explores security issues and vulnerabilities of wireless networks. An emerging application of WiFi ad hoc networks-RFID (radio frequency identification) networks based on the WiFi technology for warehouses and large retail stores-is presented. This chapter also presents another emerging application of WiFi-based networks: vehicular ad hoc networks for automobiles.


Author(s):  
Ameneh Daeinabi ◽  
Akbar Ghaffarpour Rahbar

Vehicular Ad Hoc Networks (VANETs) are appropriate networks that can be applied for intelligent transportation systems. Three important challenges in VANETs are studied in this chapter. The first challenge is to defend against attackers. Because of the lack of a coordination unit in a VANET, vehicles should cooperate together and monitor each other in order to enhance security performance of the VANET. As the second challenge in VANETs, scalability is a critical issue for a network designer. Clustering is one solution for the scalability problem and is vital for efficient resource consumption and load balancing in large scale VANETs. On the other hand, due to the high-rate topology changes and high variability in vehicles density, transmission range of a vehicle is an important issue for forwarding and receiving messages. In this chapter, we study the clustering algorithms, the solutions appropriate to increase connectivity, and the algorithms that can detect attackers in a VANET.


2012 ◽  
Vol 8 (1) ◽  
pp. 45-59 ◽  
Author(s):  
Sunwoo Kim ◽  
Won W. Ro

Network coding is a promising technique for data communications in wired and wireless networks. However, it places an additional computing overhead on the receiving node in exchange for the improved bandwidth. This paper proposes an FPGA-based reconfigurable and parallelized network coding decoder for embedded systems especially for vehicular ad hoc networks. In our design, rapid decoding process can be achieved by exploiting parallelism in the coefficient vector operations. The proposed decoder is implemented by using a modern Xilinx Virtex-5 device and its performance is evaluated considering the performance of the software decoding on various embedded processors. The performance on four different sizes of the coefficient matrix is measured and the decoding throughput of 18.3 Mbps for the size 16 × 16 and 6.5 Mbps for 128 × 128 has been achieved at the operating frequency of 64.5 MHz. Compared to the recent TEGRA 250 processor, the result obtained with128 × 128 coefficient matrix reaches up to 5.06 in terms of speedup.


Sign in / Sign up

Export Citation Format

Share Document