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Analytical Evaluation of Proactive Routing Protocols with Route Stabilities under two Radio Propagation Models
Abstract
This paper contributes to modeling links and route stabilities in three diverse wireless routing protocols. For this purpose, we select three extensively utilized proactive protocols; Destination-Sequenced Distance Vector (DSDV), Optimized Link State Routing (OLSR) and Fish-eye State Routing (FSR). We also enhance the performance of these protocols by modifying default parameters. Optimization of these routing protocols are done via performance metrics, i.e., average Throughput, End to End Delay (E2ED) and Normalized Routing Load (NRL) achieved by them. Default routing protocols DSDV, OLSR and FSR are compared and evaluated with modified versions named as M-DSDV, M-OLSR and M-FSR using Network Simulator (NS2). Numerical Computations for Route Stabilities of these routing protocols through a mathematical modeled equation is determined and compared with simulation results. Moreover, all-inclusive evaluation and scrutiny of these proactive routing protocols are done under the MAC layer standards 802.11 DCF and 802.11e EDCF. In this way both Network and MAC layer exploration has been done under the performance metrics which gives overall performance and tradeoff with respect to full utilization of the available resources of Ad-hoc network high scalability scenario. Routing latency effects with respect to route stabilities and MAC layer standards 802.11 and 802.11e are compared and scrutinized with the tradeoff observed in throughput and in overhead (NRL) generated.
... The ns-2 [46] simulator was used during this validation process because it allows us to model several network scenarios and collect statistics through trace files. The OLSR model and also the model used by the ns-2 simulator to evaluate the network performance are described in [47]. Using this simulation tool we defined several network topologies, configure wireless network interfaces and set the node mobility patterns. ...
The adoption of mobile and ubiquitous solutions that involve participatory or opportunistic sensing increases every day. This situation has highlighted the relevance of optimizing the energy consumption of these solutions, because their operation depends on the devices' battery lifetimes. This article presents a study that intends to understand how the prediction of topology control messages in human-centric wireless sensor networks can be used to help reduce the energy consumption of the participating devices. In order to do that, five research questions have been defined and a study based on simulations was conducted to answer these questions. The obtained results help identify suitable mobile computing scenarios where the prediction of topology control messages can be used to save energy of the network nodes. These results also allow estimating the percentage of energy saving that can be expected, according to the features of the work scenario and the participants behavior. Designers of mobile collaborative applications that involve participatory or opportunistic sensing, can take advantage of these findings to increase the autonomy of their solutions.
This document describes the Optimized Link State Routing (OLSR)
protocol for mobile ad hoc networks. The protocol is an optimization
of the classical link state algorithm tailored to the requirements of
a mobile wireless LAN. The key concept used in the protocol is that
of multipoint relays (MPRs). MPRs are selected nodes which forward
broadcast messages during the flooding process. This technique
substantially reduces the message overhead as compared to a classical
flooding mechanism, where every node retransmits each message when it
receives the first copy of the message. In OLSR, link state
information is generated only by nodes elected as MPRs. Thus, a
second optimization is achieved by minimizing the number of control
messages flooded in the network. As a third optimization, an MPR
node may chose to report only links between itself and its MPR
selectors. Hence, as contrary to the classic link state algorithm,
partial link state information is distributed in the network. This
information is then used for route calculation. OLSR provides
optimal routes (in terms of number of hops). The protocol is
particularly suitable for large and dense networks as the technique
of MPRs works well in this context.
This paper introduces a finite load multi-class 802.11e EDCF model that is simple enough to be explicitly solvable. The model is nevertheless flexible enough to model the impact of 802.11e parameters on the prioritization of realistic traffic. We emphasize that a modeling framework which allows nonsaturated sources is essential in the study of realistic traffic. We apply the model to a situation of practical interest: competing TCP flows in an infrastructure network. The model allows us to make a principled selection of 802.11e parameters to resolve problems highlighted in this scenario. Model predictions and parameter selections are validated against simulation and experiment. The model is shown to be accurate and the parameters effective.
An analytical model is proposed to describe the priority schemes of the EDCA mechanism of the IEEE 802.11e standard. EDCA provides class-based differentiated QoS to IEEE 802.11 WLANs. The main contribution of this paper opposed to other works is that the model predicts the throughput, delay and frame dropping probabilities of the different traffic classes in the whole range from a lightly loaded, non-saturated channel to a heavily congested, saturated medium. Furthermore, the model describes differentiation based on different AIFS-values, in addition to the other adjustable parameters (i.e. window-sizes, retransmission limits, TXOP lengths etc.) also encompassed by previous models. AIFS differentiation is described by a simple equation that enables access points to predict at which traffic loads starvation of a traffic class will occur. The model is calculated numerically and validated against simulation results. We observed a good match between the analytical model and simulations.
In this paper, we provide a throughput analysis of the IEEE 802.11 protocol at the data link layer in non-saturated traffic conditions taking into account the impact of both transmission channel and capture effects in Rayleigh fading environment. The impact of both non-ideal channel and capture become important in terms of the actual observed throughput in typical network conditions whereby traffic is mainly unsaturated, especially in an environment of high interference. We extend the multi-dimensional Markovian state transition model characterizing the behavior at the MAC layer by including transmission states that account for packet transmission failures due to errors caused by propagation through the channel, along with a state characterizing the system when there are no packets to be transmitted in the buffer of a station. Finally, we derive a linear model of the throughput along with its interval of validity. Simulation results closely match the theoretical derivations confirming the effectiveness of the proposed model.
An ad-hoc network is the cooperative engagement of a collection of Mobile Hosts without the required intervention of any centralized Access Point. In this paper we present an innovative design for the operation of such ad-hoc networks. The basic idea of the design is to operate each Mobile Host as a specialized router, which periodically advertises its view of the interconnection topology with other Mobile Hosts within the network. This amounts to a new sort of routing protocol. We have investigated modifications to the basic BellmanFord routing mechanisms, as specified by the Routing Information Protocol, making it suitable for a dynamic and self-starting network mechanism as is required by users wishing to utilize ad-hoc networks. Our modifications address some of the previous objections to the use of Bellman-Ford, related to the poor looping properties of such algorithms in the face of broken links and the resulting time dependent nature of the interconnection topology describing th...
In this paper we evaluate several routing protocols for mobile, wireless, ad hoc networks via packet‐level simulations. The ad hoc networks are multi‐hop wireless networks with dynamically changing network connectivity owing to mobility. The protocol suite includes several routing protocols specifically designed for ad hoc routing, as well as more traditional protocols, such as link state and distance vector, used for dynamic networks. Performance is evaluated with respect to fraction of packets delivered, end‐to‐end delay, and routing load for a given traffic and mobility model. Both small (30 nodes) and medium sized (60 nodes) networks are used. It is observed that the new generation of on‐demand routing protocols use much lower routing load, especially with small number of peer‐to‐peer conversations. However, the traditional link state and distance vector protocols provide, in general, better packet delivery and end‐to‐end delay performance.
Arbitrary inter-frame space (AIFS), contention window (CW) and transmission opportunity (TXOP) are three important quality-of-service (QoS) differentiation schemes specified in the IEEE 802.11e enhanced distributed channel access (EDCA) protocol for wireless local area networks (WLANs). Analytical models of EDCA in the current literature have been mainly developed for the AIFS, CW, and TXOP schemes, separately. This study proposes a comprehensive analytical model to accommodate the combination of these three QoS schemes in WLANs under unsaturated traffic loads. We derive the performance metrics in terms of throughput, end-to- end delay, and frame loss probability. Extensive simulation experiments are conducted to validate the accuracy of the model.
The IEEE has standardized the 802.11 protocol for wireless local
area networks. The primary medium access control (MAC) technique of
802.11 is called the distributed coordination function (DCF). The DCF is
a carrier sense multiple access with collision avoidance (CSMA/CA)
scheme with binary slotted exponential backoff. This paper provides a
simple, but nevertheless extremely accurate, analytical model to compute
the 802.11 DCF throughput, in the assumption of finite number of
terminals and ideal channel conditions. The proposed analysis applies to
both the packet transmission schemes employed by DCF, namely, the basic
access and the RTS/CTS access mechanisms. In addition, it also applies
to a combination of the two schemes, in which packets longer than a
given threshold are transmitted according to the RTS/CTS mechanism. By
means of the proposed model, we provide an extensive throughput
performance evaluation of both access mechanisms of the 802.11 protocol
In this paper, we present a novel routing protocol for wireless ad hoc networks -- Fisheye State Routing (FSR). FSR introduces the notion of multi-level fisheye scope to reduce routing update overhead in large networks. Nodes exchange link state entries with their neighbors with a frequency which depends on distance to destination. From link state entries, nodes construct the topology map of the entire network and compute optimal routes. Simulation experiments show that FSR is simple, efficient and scalable routing solution in a mobile, ad hoc environment. 1 Introduction As the wireless and embedded computing technologies continue to advance, increasing numbers of small size and high performance computing and communication devices will be capable of tetherless communications and ad hoc wireless networking. An ad hoc wireless network is a selforganizing and self-configuring network with the capability of rapid deployment in response to application needs. An important characteristic wh...