Prediction-based Decentralized Routing Algorithm

We introduce a new efficient routing algorithm called Prediction-based Decentralized Routing algorithm (PDR), which is based on the Ant Colony Optimization (ACO) meta-heuristics. In our approach, an ant uses a combination of the link state information and the predicted link load instead of the ant's trip time to determine the amount of pheromone to deposit. A Feed Forward Neural Network (FFNN) is used to build adaptive traffic predictors which capture the actual traffic behaviour. We study two performance parameters: the rejection ratio and the percentage of accepted bandwidth under two different network load conditions. We show that our algorithm reduces the rejection ratio of requests and achieves a higher throughput when compared to Shortest Path First and Widest Shortest Path algorithms

A Novel Opportunistic Spectrum Sharing Scheme for Cognitive Ad Hoc Networks

Nowadays, wireless ad hoc networks are using a static spectrum allocation which leads to congestion in this spectrum parts as the number of devices increases. On the contrary, a significant portion of the spectrum in licensed band (e.g. TV band) is not utilized. Cognitive radio (CR) is a promising technology to solve the spectrum inefficiency problem in ad hoc networks. Based on CR, the unlicensed (secondary) users will utilize the unused spectrum of the licensed (primary) users in an opportunistic manner. As a result, the average spectrum usage will be increased. However, the sudden appearance of primary users will have a negative impact on the performance of secondary users, since secondary users must evacuate the occupied channel and handoff to another unutilized one. This process continues till an unlicensed user finishes his transmission. We will name this process consecutive spectrum handoff (CSH). In order to increase the performance of CR, the number of consecutive spectrum handoffs should be reduced. In this paper, a novel opportunistic spectrum sharing scheme under a heterogeneous spectrum environment of licensed and unlicensed bands is introduced. In this scheme, the licensed channels will be used as operating channels and the unlicensed channels will be used as backup channels when the primary user appears. Since the unlicensed channels are not interrupted by primary users, no more spectrum handoff is needed

Prediction-based decentralized routing algorithm

We introduce a new efficient routing algorithm called Prediction-based Decentralized Routing algorithm (PDR), which is based on the Ant Colony Optimization (ACO) meta-heuristics. In our approach, an ant uses a combination of the link state information and the predicted link load instead of the ant’s trip time to determine the amount of pheromone to deposit. A Feed Forward Neural Network (FFNN) is used to build adaptive traffic predictors which capture the actual traffic behaviour. We study two performance parameters: the rejection ratio and the percentage of accepted bandwidth under two different network load conditions. We show that our algorithm reduces the rejection ratio of requests and achieves a higher throughput when compared to Shortest Path First and Widest Shortest Path algorithms

The Forwarding on Gates architecture: Flexible placement of QoS functions and states in internetworks

A main driver of Future Internet applications and services is Quality of Service (QoS). Current Internet technologies provide no suitable QoS support for end-to-end connections due to several drawbacks of IntServ and DiffServ. In this article, we propose the “Forwarding on Gates” (FoG) architecture, which answers the QoS questions by the help of a new inter-network architecture. It applies its own new network protocol, which was designed to handle IntServ and DiffServ in an integrated way. FoG supports resource reservations for QoS guarantees in IntServ scenarios and prioritized traffic in DiffServ scenarios as well as a combination of both. As core advantage, the QoS support of FoG works in a scalable way by allowing a network to move QoS states and delegate decisions about the QoS usage to the entities demanding for QoS. This article describes the architecture, its network protocol, and solutions for interoperability with current networks. The evaluation includes theoretical descriptions of network configurations for a use case not supported by IP. Moreover, simulations show that the protocol overhead is comparable to IPv6, although packets can select QoS explicitly. Measured routing graph sizes for various setups show the flexibility of the FoG architecture