scispace - formally typeset
Search or ask a question
Book Chapter•DOI•

Adaptive V2V Routing with RSUs and Gateway Support to Enhance Network Performance in VANET

Jims Marchang1, Benjamin Sanders2, Dany Joy3•
Sheffield Hallam University1, University of Winchester2, University of Plymouth3
18 Jun 2018-pp 298-310
TL;DR: RSUs are used in this paper for route discovery within one gateway zone when a next hop vehicle to relay the route request packet is unavailable and a local route repair is attempted to maintain a more stable link with the help of RSUs.
Abstract: In a VANET communication, link stability can neither be guaranteed nor make the established route link permanent due to the dynamic nature of the network. In V2V communication without the involvement of any infrastructural units like RSU access points or gateway, the probability of successful link establishment decreases when vehicle’s speed varies, red traffic light increases, cross-road increases and finally when the density of the running vehicles is sparse. To ensure route establishment and control route request broadcast in a sparse VANET with cross-road layout, RSUs are used in this paper for route discovery within one gateway zone when a next hop vehicle to relay the route request packet is unavailable. RSUs are static but the vehicles are dynamic in nature, so relying completely on RSU for forwarding data is not recommended because chances of link failure, link re-establishment, and handoff overhead will be high. So, in this paper, RSUs and Gateways are evoked for route discovery and data forwarding only when necessary. Moreover, a local route repair is attempted in this paper when the path length is high to reduce or avoid loss of buffered packets along the route and to maintain a more stable link with the help of RSUs.

Summary (2 min read)

Jump to: [1. Introduction] – [2. Relevant Background Study] – [3. Assumptions] – [4. Proposed Adaptive Routing] and [5. Network Settings, Results, and Discussion]

1. Introduction

  • In building and integrating a smart traffic management system and incorporate each vehicle to become a part of the Internet of Things (IoT) entity, Vehicle Ad Hoc Network is a vital component.
  • Route undiscoverable situation in V2V is not uncommon especially when vehicle density is too low, and the destination is too far away because the probability of missing next hop link increases because of the dynamic nature of the vehicles in VANET and the physical structure of roads and highways (straight, cross-road, curve etc.).
  • Some may argue that without RSU, information collection and distribution from and to the vehicles can be executed directly using internet; however, in a bandwidth hungry world with limited wireless network resources, RSUs and Gateways play a crucial role in collecting and disseminating information from and to the vehicles by targeting only the region of interest.
  • If vehicle distribution density is low and if one of the potential relay vehicles accelerate or slows down or take a turn in the ring road as shown in Figure 2, the link stability between the source and destination decreases.
  • In order to ensure a more stable link, this paper proposed a routing mechanism which uses the support of RSUs in absence of next hop relay vehicle and conducts a local link repair if the link is broken closer to the destination to reduce route discovery overhead and overall data loss.

2. Relevant Background Study

  • The RSUs are static and available always, so various authors take an advantage of the presence of RSUs and use in discovering path between a source and a destination.
  • It was investigated in [5] that even with a small number of RSUs, the probability of network connectivity, delay and the message penetration time are significantly improved in VANET.
  • In an ever-changing dynamic network due to high mobility maintaining accuracy about minimum message delivery time to relay within its neighborhood will be a challenge.
  • The path from source to destination is made by using road id's and Gateway nodes assist in locating the destination and forward packets from one segment of a road to other [10].
  • In order to ensure limited delay, bound packet forwarding, RSUs are used by placing minimal number of RSUs in the system at the right spots [11].

3. Assumptions

  • In implementing and testing to validate the proposed routing mechanism, using network simulator NS2, there are some assumptions considered about the test environment.
  • As described by the authors of [12], this work also follows a simple wireless communication model with a perfect radio propagation channel as used in academic practice with the following assumptions: i. The surface of communication is flat.
  • If node A can hear node B, then node B can also hear node A when nodes don't move and use same transmission power.
  • Other assumptions include, vehicles travel with the same average speed at all time and the RSUs are functional at all time and a local gateway is installed in every ringroad as sown in Figure 3.

4. Proposed Adaptive Routing

  • The proposed routing protocol is called an adaptive V2V routing with RSUs and Gateway support (AV2VR) where the RSUs are invoked for routing only when one or more vehicles connecting the source and destination are missing or if the link is broken due to acceleration or slow down or due to changing direction in cross road.
  • In an event of missing next hop vehicle in V2V communication, during the route request initiation, the route request packets are not forwarded throughout the network in this study, rather the relay or forwarding of the route request packets are restricted by the record in RSUs or local Gateway.
  • When one of the RSUs respond to the local Gateway about the destinations, the rest of the other RSUs in the ring-road terminates the route request broadcast.
  • In order to avoid frequent re-routing or re-discover of route due to vehicle’s speed, direction, density and limited transmission range of the vehicles, the transmission range of the RSUs can be made much higher to maintain longer link stability and provide better scope of handoff since RSUs are stationary in nature.

5. Network Settings, Results, and Discussion

  • To analyze the performance of the proposed routing protocol a network topology of Figure 5 is considered, where vehicles are sparsely spaced and tested with an average speed of 20m/s and 40m/s.
  • So, packets keep forwarded from the source vehicle hoping to eventually repair the broken link, but it never happened, rather the buffer gets overflowed and packets get dropped eventually, leading high loss rate as the offered load increases.
  • Roadside Units as message routers in VANETs, also known as ROAMER.

Did you find this useful? Give us your feedback

Figures (10)

Content maybe subject to copyright    Report

Citations
More filters
Journal Article•DOI•
A Survey of VANET/V2X Routing From the Perspective of Non-Learning- and Learning-Based Approaches

[...]

01 Jan 2022-IEEE Access
TL;DR: In this paper , the authors categorize the routing mechanisms as non-learning-and learning-based approaches, and discuss existing V2X routing protocols and their contributions to and impacts on VANET performance.
Abstract: Intelligent transportation systems (ITSs) have become increasingly popular because they support effective coordination in connected vehicles. ITSs present an integrated approach for exchanging relevant information in order to improve the safety, efficiency, and reliability of road transportation systems. A variant of mobile ad-hoc networks (MANETs) called vehicular ad-hoc networks (VANETs) are an integral component of ITSs. VANETs consist of interconnected vehicles with sensing abilities that exchange information related to traffic, positioning, weather, and emergency services. In general, vehicle-to-everything (V2X) refers to communications between any entity and a vehicle, where the entity may be a vehicle, a cloud-based network, a pedestrian, or equipment installed along a road. One of the crucial challenges in V2X is the reliable and timely circulation of information among vehicular nodes to allow drivers to make decisions that increase road safety. In this context, efficient V2X routing protocols play a key role in supporting reliability and safety, and enhancing the overall quality of service (QoS) in VANETs. However, VANETs have distinct characteristics, such as high vehicular node mobility, unsteady connectivity, rapid changes in network topology, and unbounded network size, that can significantly affect routing in the network. Various routing protocols for V2X communication exist in the open technical literature. In this survey, we categorize the routing mechanisms as non-learning- and learning-based approaches, and discuss existing V2X routing protocols and their contributions to and impacts on VANET performance. Here, the learning-based approach implies the use of machine learning algorithms. This survey also summarizes open challenges in designing effective V2X routing protocols and future research directions to consider when developing smart routing mechanisms for next-generation intelligent VANET technologies.

12 citations

Journal Article•DOI•
A Survey of VANET/V2X Routing From the Perspective of Non-Learning- and Learning-Based Approaches

[...]

Twinkle Chatterjee, Raja Karmakar, Georges Kaddoum, S. K. Chattopadhyay, Subrata Chakraborty 
IEEE Access
TL;DR: This survey categorizes the routing mechanisms as non-learning- and learning-based approaches, and discusses existing V2X routing protocols and their contributions to and impacts on VANET performance.
Abstract: Intelligent transportation systems (ITSs) have become increasingly popular because they support effective coordination in connected vehicles. ITSs present an integrated approach for exchanging relevant information in order to improve the safety, efficiency, and reliability of road transportation systems. A variant of mobile ad-hoc networks (MANETs) called vehicular ad-hoc networks (VANETs) are an integral component of ITSs. VANETs consist of interconnected vehicles with sensing abilities that exchange information related to traffic, positioning, weather, and emergency services. In general, vehicle-to-everything (V2X) refers to communications between any entity and a vehicle, where the entity may be a vehicle, a cloud-based network, a pedestrian, or equipment installed along a road. One of the crucial challenges in V2X is the reliable and timely circulation of information among vehicular nodes to allow drivers to make decisions that increase road safety. In this context, efficient V2X routing protocols play a key role in supporting reliability and safety, and enhancing the overall quality of service (QoS) in VANETs. However, VANETs have distinct characteristics, such as high vehicular node mobility, unsteady connectivity, rapid changes in network topology, and unbounded network size, that can significantly affect routing in the network. Various routing protocols for V2X communication exist in the open technical literature. In this survey, we categorize the routing mechanisms as non-learning- and learning-based approaches, and discuss existing V2X routing protocols and their contributions to and impacts on VANET performance. Here, the learning-based approach implies the use of machine learning algorithms. This survey also summarizes open challenges in designing effective V2X routing protocols and future research directions to consider when developing smart routing mechanisms for next-generation intelligent VANET technologies.

10 citations

Proceedings Article•DOI•
An Efficacy of Transmission Power on DYMO Routing Protocol in VANET

[...]

04 Jul 2022
TL;DR: In this paper , the authors presented the evaluation of Dynamic MANET On-Demand (DYMO) routing protocol for a vehicular network with a single RSU in order to elaborate the influence of different transmission power values on QoS parameters.
Abstract: A Vehicular Ad hoc Network (VANET) is made up of groups of moving or stationary vehicles that are linked by a wireless network. It arose from the concept of creating an automobiles network to achieve a specific need or situation, such as Intelligent Transport System (ITS) and smart cities. VANET are now recognized as reliable network that vehicles are used for communication on highways and in cities. Basically, when the vehicles communicate with one another directly is known as Vehicle to Vehicle (V2V), or it can communicate with Infrastructure or a Road-side Unit (RSU so it is called Vehicle to Infrastructure (V2I) and Vehicle to Everything (V2X). This paper presents the evaluation of Dynamic MANET On-Demand (DYMO) routing protocol for a vehicular network with a single RSU in order to elaborate the influence of different transmission power values on QoS parameters. The simulation results are obtained using OMNeT++ with INET and Veins frameworks communicate with a SUMO traffic road simulator to implement DYMO. The findings depict a good foundation for researchers in evaluating the efficacy of transmission power of the vehicles on the QoS metrics of DYMO routing protocol in terms of packet delivery ratio, normalized routing load, throughput and packet loss ratio in a VANET environment.
Proceedings Article•DOI•
Chain Branch Leaf-Gateway, a Strategy for Dynamic Clustering and Optimal Coverage of Communication for Automated Mobility

[...]

Sabrine Belmekki, Dominique Gruyer, Charles Tatkeu
24 Oct 2022
TL;DR: In this article , the authors proposed an improvement of the Chain Branch Leaf (CBL) strategy with the implementation of a Gateway mechanism (cBL-G) in order to guarantee V2X architecture.
Abstract: One of the main issues with embedded sensors in Automated Vehicle (AV) concerns their limited perception capabilities (limited range) and short-term reaction to only close events. However, for safer operations, AVs need to anticipate distant events. To reach this goal, it is essential to propose efficient communication architectures and strategies that guarantee a high level of Quality of Service (QoS). Therefore, cooperation among communication “nodes” is essential to establish and maintain the links between vehicles or vehicles and infrastructure. However, the communication links could be interrupted in some situations such as Vehicles leaving the area covered by the communications (vehicle alone or in low vehicle density), or the high velocity of vehicles (reduced range). This paper proposes an improvement of the Chain Branch Leaf (CBL) strategy with the implementation of a Gateway mechanism (CBL-G). The initial Vehicle-to-Vehicle (V2V) strategy is now extended with a Vehicle-to-Infrastructure (V2I) configuration in motorway areas in order to guarantee V2X architecture. CBL-G objective is to develop a dynamic communication clustering strategy with a distributed and dedicated Road Side Units (RSU) topology for optimal communication coverage. The proposed solution improves the QoS for critical functions (i.e risk assessment, accurate and distributed localization) by redirecting isolated vehicle nodes and clusters to RSUs.
Proceedings Article•DOI•
Chain Branch Leaf-Gateway, a Strategy for Dynamic Clustering and Optimal Coverage of Communication for Automated Mobility

[...]

24 Oct 2022
TL;DR: In this paper , the authors proposed an improvement of the Chain Branch Leaf (CBL) strategy with the implementation of a Gateway mechanism (cBL-G) in order to guarantee V2X architecture.
Abstract: One of the main issues with embedded sensors in Automated Vehicle (AV) concerns their limited perception capabilities (limited range) and short-term reaction to only close events. However, for safer operations, AVs need to anticipate distant events. To reach this goal, it is essential to propose efficient communication architectures and strategies that guarantee a high level of Quality of Service (QoS). Therefore, cooperation among communication “nodes” is essential to establish and maintain the links between vehicles or vehicles and infrastructure. However, the communication links could be interrupted in some situations such as Vehicles leaving the area covered by the communications (vehicle alone or in low vehicle density), or the high velocity of vehicles (reduced range). This paper proposes an improvement of the Chain Branch Leaf (CBL) strategy with the implementation of a Gateway mechanism (CBL-G). The initial Vehicle-to-Vehicle (V2V) strategy is now extended with a Vehicle-to-Infrastructure (V2I) configuration in motorway areas in order to guarantee V2X architecture. CBL-G objective is to develop a dynamic communication clustering strategy with a distributed and dedicated Road Side Units (RSU) topology for optimal communication coverage. The proposed solution improves the QoS for critical functions (i.e risk assessment, accurate and distributed localization) by redirecting isolated vehicle nodes and clusters to RSUs.
References
More filters
Ad hoc On-Demand Distance Vector (AODV) Routing

[...]

Charles E. Perkins, Elizabeth M. Belding-Royer, Samir R. Das
01 Jul 2003
TL;DR: A logging instrument contains a pulsed neutron source and a pair of radiation detectors spaced along the length of the instrument to provide an indication of formation porosity which is substantially independent of the formation salinity.
Abstract: The Ad hoc On-Demand Distance Vector (AODV) routing protocol is intended for use by mobile nodes in an ad hoc network. It offers quick adaptation to dynamic link conditions, low processing and memory overhead, low network utilization, and determines unicast routes to destinations within the ad hoc network. It uses destination sequence numbers to ensure loop freedom at all times (even in the face of anomalous delivery of routing control messages), avoiding problems (such as "counting to infinity") associated with classical distance vector protocols.

11,490 citations

Proceedings Article•DOI•
Experimental evaluation of wireless simulation assumptions

[...]

David Kotz1, Calvin Newport1, Robert S. Gray1, Jason Liu2, Yougu Yuan1, Chip Elliott •
Dartmouth College1, Colorado School of Mines2
04 Oct 2004
TL;DR: A comprehensive review of six assumptions that are still part of many ad hoc network simulation studies, despite increasing awareness of the need to represent more realistic features, including hills, obstacles, link asymmetries, and unpredictable fading are provided.
Abstract: All analytical and simulation research on ad~hoc wireless networks must necessarily model radio propagation using simplifying assumptions. We provide a comprehensive review of six assumptions that are still part of many ad hoc network simulation studies, despite increasing awareness of the need to represent more realistic features, including hills, obstacles, link asymmetries, and unpredictable fading. We use an extensive set of measurements from a large outdoor routing experiment to demonstrate the weakness of these assumptions, and show how these assumptions cause simulation results to differ significantly from experimental results. We close with a series of recommendations for researchers, whether they develop protocols, analytic models, or simulators for ad~hoc wireless networks.

627 citations

Journal Article•DOI•
Enhancing VANET Connectivity Through Roadside Units on Highways

[...]

Sok-Ian Sou1, Ozan K. Tonguz2•
National Cheng Kung University1, Carnegie Mellon University2
22 Aug 2011-IEEE Transactions on Vehicular Technology
TL;DR: The results show that, even with a small number of RSUs, the performance in terms of the probability of network connectivity, the rehealing delay, the number of rehealing hops, and the message penetration time can be significantly improved in highway VANET scenarios.
Abstract: In vehicular ad hoc network (VANET) safety applications, the source vehicle that detects an accident can generate a warning message and propagate it to the following vehicles to notify other drivers before they reach the potential danger zone on the road. Recent studies have shown that sparse vehicle traffic leads to network fragmentation, which poses a crucial research challenge for safety applications. In this paper, we analyze and quantify the improvement in VANET connectivity when a limited number of roadside units (RSUs) are deployed and to investigate the routing performance for broadcast-based safety applications in this enhanced VANET environment. Our results show that, even with a small number of RSUs, the performance in terms of the probability of network connectivity, the rehealing delay, the number of rehealing hops, and the message penetration time can be significantly improved in highway VANET scenarios.

154 citations

"Adaptive V2V Routing with RSUs and ..." refers background in this paper

  • ...It was investigated in [5] that even with a small number of RSUs, the probability of network connectivity, delay and the message penetration time are significantly improved in VANET....

    [...]

Journal Article•DOI•
ROAMER: Roadside Units as message routers in VANETs

[...]

Khaleel Mershad1, Hassan Artail1, Mario Gerla2•
American University of Beirut1, University of California, Los Angeles2
01 May 2012
TL;DR: This is the first attempt to use the RSU backbone to efficiently route packets to very far locations in VANETs by using geographic forwarding and is compared to existing solutions and proves the feasibility and efficiency of the scheme in terms of query delay, packet success delivery ratio, and total generated traffic.
Abstract: Vehicular Ad hoc Networks, also known as VANETs, enable vehicles that are not necessarily within the same radio transmission range to communicate with each other. VANETs also allow vehicles to connect to Roadside Units (RSUs). The latter are connected to the Internet, forming a fixed infrastructure that offers them the capability of communicating with each other and with roaming vehicles. RSUs support cooperative and distributed applications in which vehicles and RSUs work together to coordinate actions and to share and process several types of information. RSUs have so far been used for different roles such as data disseminators, traffic directories, location servers, security managers, and service proxies. In this paper, we focus on routing; namely we exploit RSUs to route packets between any source and destination in the VANET. To our knowledge, this is the first attempt to use the RSU backbone to efficiently route packets to very far locations in VANETs by using geographic forwarding. We evaluate the RSU backbone routing performance via the ns2 simulation platform. We compare our scheme to existing solutions and prove the feasibility and efficiency of our scheme in terms of query delay, packet success delivery ratio, and total generated traffic.

108 citations

"Adaptive V2V Routing with RSUs and ..." refers methods in this paper

  • ...The authors of [4] use RSU backbone to route packets to in VANETs by using geographic forwarding....

    [...]

Posted Content•
VANET Connectivity Analysis

[...]

Mohamed Kafsi, Panos Papadimitratos, Olivier Dousse, Tansu Alpcan, Jean-Pierre Hubaux 
30 Dec 2009-arXiv: Networking and Internet Architecture
TL;DR: A thorough analysis of the connectivity of VANETs by leveraging on wellknown results of percolation theory to assess the feasibility and performance of future applications relying on vehicular connectivity in urban scenarios.
Abstract: Vehicular Ad Hoc Networks (VANETs) are a peculiar subclass of mobile ad hoc networks that raise a number of technical challenges, notably from the point of view of their mobility models. In this paper, we provide a thorough analysis of the connectivity of such networks by leveraging on well-known results of percolation theory. By means of simulations, we study the influence of a number of parameters, including vehicle density, proportion of equipped vehicles, and radio communication range. We also study the influence of traffic lights and roadside units. Our results provide insights on the behavior of connectivity. We believe this paper to be a valuable framework to assess the feasibility and performance of future applications relying on vehicular connectivity in urban scenarios.

79 citations

"Adaptive V2V Routing with RSUs and ..." refers background in this paper

  • ...Moreover, the connectivity of VANET is not determined only by RSU, but rather there are other factors like vehicle density, distribution, traffic lights, vehicles speed and communication range in governing the connectivity in VANET [7]....

    [...]

Related Papers (5)
Temporary Parallel Route Recovery for Frequent Link Failure in VANET

[...]

01 Jan 2012
B. Siva Kumar Reddy, M. Sakthi Ganesh, P. Venkata Krishna
Reduction of Routing Overhead in Vehicle-to-Vehicle Communication using Clustering in Vehicular Ad-hoc Networks

[...]

01 May 2017
Rajesh Kolluri
Mobility Information and Road Topology Based Inter-vehicle Routing Protocol in Urban

[...]

22 Sep 2011
Si-Ho Cha, Keun-Wang Lee
An Enhanced Connectivity Aware Routing Protocol for Vehicular Ad hoc Networks

[...]

01 Jan 2014-Research Journal of Applied Sciences, Engineering and Technology
Ahmadu Maidorawa, Kamalrulnizam Abu Bakar
A Predictive Route Maintenance Protocol Based on Signal Strength for Dense Ad Hoc Networks

[...]

01 Jan 2012-International Journal of Computer Theory and Engineering
Sharmila Sankar, V. Sankaranarayanan
Frequently Asked Questions (19)
Q1. What is the reason for the loss of data in LL repair AODV?

In a distributed data communication of wireless networks, loss of data is mainly due to buffer overflow, data collision, exceeding the data retransmission limit and total link failure leading to loss of buffered packets. 

In order to ensure limited delay, bound packet forwarding, RSUs are used by placing minimal number of RSUs in the system at the right spots [11]. 

When the offered load is high i.e. 1000 kb/s, the loss due to buffer overflow is only approximately 20% in the proposed AV2VR routing mechanism, but the loss in LL repair AODV is as high as approximately 50% because LL repair AODV could not conduct local link repair because of lack of next hop relay vehicle in a sparse vehicle density. 

For a RSU with a transmission range of 250m, a vehicle with a speed of 20m/swill take 25 second to cover from one end to the other i.e. 500m [Time= ⁄ ]. 

When a local link repair could not be conducted and a new route is established then all the earlier buffered packets along the older routes are dropped, so local link repair is a must when path length has high hop, which is the reason why a local link repair is conducted in AV2VR if the route path length Ɽ ≥ 5.6. 

in the proposed AV2VR routing mechanism, in absence of next hop relay vehicle in a sparse vehicle density, a neighbor RSU is discovered to relay packets to the destination. 

In building and integrating a smart traffic management system and incorporate each vehicle to become a part of the Internet of Things (IoT) entity, Vehicle Ad Hoc Network (VANET) is a vital component. 

In order to avoid frequent re-routing or re-discover of route due to vehicle’s speed, direction, density and limited transmission range of the vehicles, the transmission range of the RSUs can be made much higher to maintain longer link stability and provide better scope of handoff since RSUs are stationary in nature. 

The future work will also cover the optimization of path length, RSU installation and explore its corresponding theoretical analysis aspect. 

The performance of AV2VR routing provides much higher throughput compared to LL repair AODV and achieve a throughput of 3 times more with any given load. 

In this network setting, the destination vehicle reaches the crossroad at the 25th second before taking a turn and move in different direction and breaks the link and due to the absence of potential relay neighborhood vehicle, the local link repair could not be conducted in LL repair AODV. 

Some may argue that without RSU, information collection and distribution from and to the vehicles can be executed directly using internet; however, in a bandwidth hungry world with limited wireless network resources, RSUs and Gateways play a crucial role in collecting and disseminating information from and to the vehicles by targeting only the region of interest. 

It means that link repair is conducted only for high path length and when a link failure point is closer to the destination compared to the source’s hop count. 

The local link repair AODV yield comparatively low throughput because once the link is broken and if the link repair cannot be completed the source may continue to send packet up to the point where the link is broken with a hope of repairing the broken link. 

In implementing and testing to validate the proposed routing mechanism, using network simulator NS2, there are some assumptions considered about the test environment. 

In LL repair AODV based routing the loss is evident from low offered load of 100kb/s to a high network offered load of 1000kb/s as shown in Figure 7. 

To analyze the performance of the proposed routing protocol a network topology of Figure 5 is considered, where vehicles are sparsely spaced and tested with an average speed of 20m/s and 40m/s. 

The saturation point will be different depending on the path length of the route since the throughput is inversely proportional to the hop. 

As shown in Figure 6, the end-to-end network performance increases as the offered load increases, however, the network gets saturated above 750kb/s offered load.