Routing In Cognitive Radio Ad Hoc Networks Research Articles

Cluster based routing in cognitive radio adhoc networks: Reconnoitering SINR and ETT impact on clustering

A novel clustering approach for Cognitive Radio Ad Hoc Networks (CRAHNs) is proposed in this paper. The Signal to Interference and Noise Ratio (SINR) produced by Primary Users (PUs) on collocated Cognitive Users (CUs) along with Expected Transmission Time (ETT) among CUs is taken into account for cluster formation. The primary concern of the proposed work is to find a suitable method of cluster formation for efficient routing in CRAHN. The suggested algorithm is simulated in ns-3. Through the observed results, values of some base parameters for efficient clustering are established. Efficiency of the proposed approach is also compared with three existing cluster based protocols. Results reveal that the proposed algorithm performs better. One cluster maintenance algorithm is also proposed in the paper. Future scope of the work is outlined.

Using Hybrid Evolutionary Algorithm based Adaptive Filtering

Noise degrades the overall efficiency of the data transmission in the networking models which is no different in Cognitive Radio Adhoc Networks (CRAHNs). For efficient opportunistic routing in CRAHN, the Modified SMOR (M-SMOR) and Sparsity based Distributed Spectrum Map M-SMOR (SDS-M-SMOR) have been developed which provide significant improvement in the overall routing behavior. However, the increase in the noises is inevitable especially in large scale networks which Swarm Optimization (PSO) and Genetic Algorithm (GA) together termed as HPSOGA. The proposed HPSOGA based adaptive filter readjusts the filter constraints in accordance to the channel and the signals, thus mitigates the noise in the reconfigurable systems, like CRAHNs. The key benefit of the HPSOGA based adaptive filter is the global optimization when compared to other, the proposed model with noise cancellation has better performance values than other routing models.

Cognitive cross-layer multipath probabilistic routing for cognitive networks

Mobile Ad-hoc NETworks (MANETs) is a set of mobile nodes that can move around arbitrarily, and communicate with others in a multi-hop fashion without any assistance of base stations. With recent advances in Cognitive Radio (CR) technology, it is possible to apply the Dynamic Spectrum Access model in MANETs. This introduces the concept of Cognitive Radio Ad Hoc Networks (CRAHNs). Applying CR techniques provides better throughput, even in congested spectrum along with better propagation characteristics. CRAHN is a kind of intelligent network that is aware of its surrounding environment, and adapts to the transmission or reception parameters to achieve efficient communication without interfering with primary users. Routing in CR environment is a challenging task as the availability of channel is constrained by the presence of primary user. The problem of routing in CRAHNs targets the creation and maintenance of wireless multi-hop paths among cognitive nodes by deciding both the spectrum to be used and the relay nodes of the path. This paper proposes a cognitive cross-layer multipath probabilistic routing for cognitive radio based networks. The proposed solution uses spectrum holes identified by MAC layer, decides the channel to be used and transmit power level for each hop in the path. The proposed solution is implemented in NS2, and performance of the proposed solution is compared with the existing solution from the literature. The paper also shows that the proposed solution outperforms existing solution in terms of packet delivery ratio, average end-to-end delay and energy consumed per data packet.

Noncooperative Differential Game Based Efficiency-aware Traffic Assignment for Multipath Routing in CRAHN

Comparing to the traditional multihop ad hoc networks, dynamic spectrum environment is the special characteristic of CRAHN (cognitive radio ad hoc networks). Therefore, the cognitive users will show their selfishness on spectrum bandwidth cost in multihop communication. In CRAHN, multipath routing is a reasonable choice when considering efficiency and stability. In order to take further advantage of efficiency of multipath routing, this paper study the efficiency-awareness traffic assignment problem of multipath routing in CRAHN. There are several existing game based traffic assignment schemes for selfish wireless network, however, all of them can not be directly applicable to CRAHN. In addition, none of the existing works studied whether the scheme is efficient. In this paper, a noncooperative differential game is proposed, and the equilibrium of the game is computed and proved to be an efficient traffic assignment for multipath routing in CRAHN. Besides this, we also optimize the total cost of game from the game designer's point of view, and give a simple example to illustrate the optimization procedure.