Neeraj Tyagi

Vehicle assisted cross-layer handover scheme in NEMO-based VANETs (VANEMO)

The combination of VANET and NEMO is termed as VANEMO. In this paper, we propose the use of ad hoc communications between vehicles in VANEMO to assist seamless NEMO handover in vehicular scenario. Using cross-layer information, a vehicle which is undergoing handover process, can take assistance from other vehicles in the ad hoc region to reduce handover latency as well as to minimise packet loss during handover. Using other vehicles assistance, a handover vehicle can get the router advertisement of the next access point before actual handover takes place. Thus, it can configure its new care-of-address on the fly, resulting in considerable reduction in handover latency. At the same time, another vehicle in the ad hoc region may assist in receiving packets destined for handover vehicle, resulting in minimisation of packet loss during handover period. The main contribution of this paper is to optimise handover latency and minimise packet loss based on the uses of mixed ad hoc and infrastructure communications, thus enabling vehicle to infrastructure communications to be improved. The proposed solution is characterised and evaluated through extensive simulation, showing that it provides an efficient handover in vehicular communications.

An enhancement of AODV routing protocol for wireless ad hoc networks

Wireless ad hoc network is an infrastructure less, self organized, multi hop packet switched network. In an ad hoc network, node movement results in dynamic topology and cause link failures. In this paper, we are using packet scheduling technique for Ad Hoc on Demand Distance Vector (AODV) routing protocol. We are using weight hop based scheduling for AODV routing protocols. In this paper, intermediate node starts the packet scheduling and manages its buffer memory according to data transfer rate. For link break, intermediate store the data packets and repair the broken route and manage over flow of data packets. We try to send the data packet by using alternate routes instead of dropping it. We analyze the proposed technique on NS-2.34 simulator. Simulation results show that proposed scheme performance is better than AODV.

Fox-Hole Model for Data-centric Misbehaviour Detection in VANETs

Broadcasting false traffic information in VANETs is one of the major security concerns. Detecting false data sent by misbehaving nodes has been a major challenge in recent times. In this paper, we are going to present a simple scheme for detection of correctness of information regarding happening of an event like a road crash. It uses the data collected from the movement of other vehicles on the road who can observe the event and measuring their response towards it. Our misbehaviour detection scheme (MDS) is data-centric meaning it figures out whether the information received is true. Vehicles may send false information just to gain access to a whole lane in a congested area. For fast moving traffic, it thus becomes more important to find the truth-value of a broadcasted alert rather than exactly finding the misbehaving node. Our scheme is not based upon voting but observing the actual movement of nodes in response to the detected event. After describing the model in detail and the mathematical equation behind the MDS, we will present certain scenarios as a justification of our scheme. At the end, we will highlight the advantages and certain limitations of our MDS as a comparative study.

Media independent handover for seamless mobility in IEEE 802.11 and UMTS based on IEEE 802.21

Multiple types of networks are evolving with different radio technologies (RATs) which are having different capabilities, price and performance ratio. When these networks are collocated with each other and when mobile devices roam around across these networks, a heterogeneous network access is formed. Each mobile device is equipped with multiple interfaces to access all types of networks of heterogeneous system. Multiple interfaces can be included in the mobile device by using separate hardware and software modules. The mobile user always wanted to be Always Best Connected (ABC) as per its requirements and availability in a given scenario. When the mobile user leaves and joins the networks, a handover operation is performed. The Handover operation is used to achieve seamless mobility. Handover operation is of two types, one is in between the same RAT and the other is in between the different RAT. For seamless and smooth handover operations across heterogeneous networks, IEEE has defined a standard named as IEEE 802.21. This paper presents a novel vertical handover scheme applicable for IEEE 802.11 (WLAN) and Universal Mobile Telecommunication System (UMTS) based on IEEE 802.21. UMTS is a 3GPP (Third Generation Partnership Project) technology, which is being used in cellular networks. WLAN is a LAN technology which supports smaller coverage area than the cellular networks. Vertical handover between these two is needed because they have different RAT.

A Cross Layer Seamless Handover Scheme in IEEE 802.11p Based Vehicular Networks

In this paper, we propose a seamless handover scheme for Network Mobility (NEMO) in vehicular scenario assisted by IEEE 802.11p based ad hoc communications among vehicles. The proposed scheme reduces handover latency and minimizes packet loss during handover by utilizing cross layer information available from other vehicles in the ad hoc manner. The role of neighboring vehicles assistance to the handover vehicle is twofold. First is to get the router advertisement of the next access point in advance to actual handover, resulting in considerable reduction in handover latency. Second is to receive packets destined for handover vehicle, thus minimizing packet loss during handover period. The extensive simulation study reveals that the proposed handover scheme provides seamless network mobility handover in vehicular communication scenario.

A survey on WiMAX-3G interworking

IEEE 802.16 WiMAX provides high data rate but limited coverage area and 3G is well established network with low data rate as comparison to WiMAX network. So if we will combine both WiMAX and 3G network then it provides ubiquitous high speed data access as well as attract wider user base. In this paper we have taken component which is used in interworking architecture, security consideration, authentication procedure, fast handoff between heterogeneous (WiMAX-3G) networks. At last we will talk about effect of interworking architecture on IMS (IP multimedia subsystem) signal delay.

Enhancement of route maintenance in AODV over hybrid wireless mesh network

Wireless mesh network has been considering as promising technology for next generation that provides a better services and guarantee to different internet applications. AODV routing protocol is being considered as routing protocol in hybrid wireless mesh network. Route breaks in mobile mesh client is one of the research issues in hybrid wireless mesh network, especially if the traffic comes from internet to mobile mesh clients. To ensure the robustness of the network a link breaks in routing protocol should be able to repair as fast as possible. In this paper, we have proposed a novel mechanism for the enhancement of route maintenance features of AODV in hybrid wireless mesh networks. The proposal mechanism uses the capability of mesh router backbone in terms of minimal mobility and no constraint in power consumption. Where border mesh routers that involves in route path between the internet gateway and mobile mesh clients can finds a new route when the route breaks if a local repair is fail between mobile mesh clients. Simulation results show that the proposed approach outperforms the standard AODV under routing overhead, end to end delay, throughput, number of packet delivery ratio in hybrid Wireless mesh networks.

An Efficient Routing Protocol for Ad-Hoc Networks

A mobile ad-hoc network is infrastructure less, self organizable, multi hop packet switched network. In ad-hoc network, node movements results in dynamic topology and frequent link failures. Studies shows that on demand protocols perform better compared to table driven protocols. Ad-hoc On Demand Routing (AODV) is one of the popular on demand routing protocol. In this paper, we have proposed an innovative method by considering the MAC layer feed back to reduce the route discovery latency and routing overhead of AODV protocol. Also proposed a new approach of preemptive route maintenance to miti gate the delays and overhead incurred during the original AODV. We implemented and simulated the proposed scheme in NS 2. Simulation results show that the pro posed scheme performs better than AODV.

Performance evaluation of mobility model and routing protocols for inter vehicular communication system

Vehicular Ad hoc networks (VANETs) allow vehicles to form a self-organized network without the need for a permanent infrastructure. Successful implementations of VANET require standard network protocols, secure communication, and coverage of wireless network among vehicles as well as drivers themselves. This paper presents a simulation study of Realistic Vehicular Mobility Model on the performance study of VANET that uses topology based Ad-hoc On-Demand Distance Vector (AODV) and Dynamic Source Routing (DSR) as the routing protocol. It gives an overview of the developments of the mobility model and routing protocols for VANET.

Enhancing Greedy Routing using Fuzzy logic for Vehicular Ad hoc Networks

Intelligent Transportation Systems (ITS) has gain a lot of popularity due to much technological advancement in Vehicular Ad hoc Networks (VANETs). VANET provides safety and entertainment services to vehicle users. Therefore, constrained safety is a prominent feature for VANETs. Since the vehicular nodes typically moves fast than the nodes movement in other network such as Mobile Ad hoc Networks (MANETs), it is of great importance to design an efficient routing protocol to provide safety and comfort services to the passengers on the roads. Recently efforts have been put to use the concepts of fuzzy logic to help in the decision making process in VANETs. Fuzzy logic deals with reasoning that is approximate rather than fixed and exact. The fuzzy logic inference system became important and useful when the values of the decision criteria are not only vague but uncertain in nature. In this work, based on analysis of greedy routing for packet forwarding, we have proposed a Fuzzy Logic based Greedy Routing (FLGR) protocol. FLGR is a multihop routing protocol which is used to select the best next-hop node in multi-hop VANETs using fuzzy logic concept. We have considered two characteristics of a vehicle as an input metrics to fuzzy decision making systems. Based on the optimum function of simulation results, the FLGR effectively select the best next-hop node for further packet transmission in the network. Key-Words: Fuzzy logic, VANETs, routing protocol, greedy routing, FLGR, fuzzification.