Route Reply Packets Research Articles

Multi-bounded QoS routing protocol and performance analysis for mobile Ad Hoc network

Providing Quality of Service ( QoS) guarantee for mobile Ad Hoc network is very important due to the rapid growth of multimedia applications. The Multi-bounded QoS-aware Ad Hoc Routing ( MQAR) protocol based on AODV was proposed, which allowed intermediate node to return Route Reply ( RREP) packet and reserve resources by extending QoS routing table, and adopted local route recovery as well. The simulation results show that MQAR protocol can effectively reduce route establishing time, route recovery time and routing overload as well, and the packet delivery ratio remains high.

A new Ad Hoc routing algorithm based on minimizing the channel handoff

How to improve the performance of the wireless Ad Hoc network by utilizing the spectrum resources efficiently has become a hot research topic in recent years. In this paper we propose a reactive routing algorithm that supports multiple channels to improve the performance of the Ad Hoc network based on the minimizing of the channel handoff. Our approach allocates the communication channel during the route discovery, and notifies the allocated channel information to the corresponding node in the route reply packets. Each node in the route tries its best to choose the same channel with the upstream node without interference. The simulation results show that our algorithm performs better than the K-hop distinct protocols in both average delays and network throughputs obviously

A Beaconless Minimum Interference Based Routing Protocol to Minimize End-to-End Delay per Packet for Mobile Ad hoc Networks

The authors propose a beaconless, on-demand, mobile ad hoc network routing protocol called minimum interference based routing protocol (MIF) that minimizes the end-to-end delay per data packet. During route discovery, each node inserts its identification and location information before broadcasting the Route-Request (RREQ) message in its neighborhood. The weight of a link, called the interference index, is the number of interfering links surrounding it. Two links are said to interfere with each other, if the distance between the mid points of the two links is within the interference range. The interference index of a path is the sum of the interference index values of the constituent links. The destination selects the path with the minimum interference index value and notifies the source through the Route-Reply packet. Simulation results demonstrate that MIF incurs a significant reduction in the end-to-end delay per data packet vis-à-vis the interference-aware load balancing routing protocol.

Link stability based multicast routing scheme in MANET

The group-oriented services are one of the primary application classes that are addressed by Mobile Ad hoc Networks (MANETs) in recent years. To support such services, multicast routing is used. Thus, there is a need to design stable and reliable multicast routing protocols for MANETs to ensure better packet delivery ratio, lower delays and reduced overheads. In this paper, we propose a mesh based multicast routing scheme that finds stable multicast path from source to receivers. The multicast mesh is constructed by using route request and route reply packets with the help of multicast routing information cache and link stability database maintained at every node. The stable paths are found based on selection of stable forwarding nodes that have high stability of link connectivity. The link stability is computed by using the parameters such as received power, distance between neighboring nodes and the link quality that is assessed using bit errors in a packet. The proposed scheme is simulated over a large number of MANET nodes with wide range of mobility and the performance is evaluated. Performance of the proposed scheme is compared with two well known mesh-based multicast routing protocols, i.e., on-demand multicast routing protocol (ODMRP) and enhanced on-demand multicast routing protocol (EODMRP). It is observed that the proposed scheme produces better packet delivery ratio, reduced packet delay and reduced overheads (such as control, memory, computation, and message overheads).

On supporting reliable QoS in multi-hop multi-rate mobile ad hoc networks

Due to complicated situations such as node/link interference and traffic load, quality of service support in multi-hop multi-rate ad hoc networks remains a challenging issue. Furthermore, when mobility is present, because of frequent route change, it is even more difficult to maintain high level performance for existing real-time flows that may not tolerate serious performance degradation. In this paper, we focus on the issue of providing sufficient QoS in networks with moderate to high node mobility. We first introduce route available bandwidth (RAB), a major index for prediction of flow performance along a specific path. RAB considers various important factors such as intra-flow interference, effective link bandwidth, and channel busy time. Then, we devise a DSR based admission control scheme where the source node accepts/rejects a flow according to the RAB of the collected route when it receives a route reply packet. To handle mobility, we incorporate an additional metric of route reliability (RR) so that a path with sufficient bandwidth and reliability can be obtained. Results show that with admission control, existing flows experiences around 80---95% average delivery ratio, even for 20 m/s maximum moving speed, which is much better than 30---60% average delivery ratio when admission control is absent.

Crosscheck mechanism to identify malicious nodes in ad hoc networks

AbstractRoute falsification attacks are easy to launch in mobile ad hoc networks with on demand routing protocols that employ network‐wide flooding of control packets for route discoveries. To mitigate such attacks, we propose a p‐hop crosscheck mechanism, which requires nodes p, p ≥ 2, hops apart to authenticate and verify route reply packets using pairwise shared keys. This mechanism can detect route falsification by non‐colluding malicious nodes on‐the‐fly; furthermore, it can identify a group of at most p+1 nodes that contain the malicious nodes that caused the route falsification. Unlike intrusion detection techniques, which require extensive monitoring and sampling, the proposed crosscheck mechanism is light‐weight and fast and hence can be used to augment the existing secure routing protocols and improve intrusion detection capability. We implement a two‐hop crosscheck for an on demand ad hoc network routing protocol. Using simulations, we show that the two‐hop crosscheck mitigates attacks by multiple malicious nodes with negligible impact on performance. Copyright © 2008 John Wiley & Sons, Ltd.

A strategy to reduce the control packet load of MANETs with bidirectional links using DSR

AbstractDynamic source routing (DSR) is a robust protocol commonly applied to multi‐hop wireless mobile ad hoc networks (MANETs). In this paper, an algorithm is proposed for modifying the basic DSR protocol to enhance its performance by reducing the number of redundant route reply packets (RREPs). In the modified DSR (MDSR), for a source destination pair, the destination responds to the first received route request packet (RREQ) with an RREP, and the subsequently received RREQs, bearing the same request ID, are responded to only if the hop count is less than that of all the previously received RREQs. The performance of MDSR has been compared with that of the basic DSR for different network densities and for different mobility of nodes. Simulation results show that MDSR gives fewer control packets, less latency and a higher packet delivery ratio than DSR. Copyright © 2007 John Wiley & Sons, Ltd.

Optimized on Demand Routing Protocol of Mobile Ad Hoc Network

In this paper optimization of DSR is achieved using New Link Cache structure and Source Transparent Route Maintenance Method. The new link cache effectively utilizes the memory by caching the routes in adjacent list type of data structures. It selects the shortest hop and least congested path, which in turn reduce the control packets, route request packets, route reply packets and increase the data packets forwarded by the nodes. To solve the DSR route maintenance problem during high mobility, source transparent route maintenance method is introduced in this paper. This method has two schemes namely cache validation and local route repair. These schemes reduce the packet loss, end-to-end delay and increase the throughput.