Routing Protocol For Cognitive Radio Research Articles

Primary user supported routing protocol for cognitive radio ad hoc networks in search of higher throughput

SummaryA routing protocol for cognitive radio ad hoc networks (CRAHNs), namely, primary user supported routing (PSR) is demonstrated in this research. Unlike existing routing protocols for CRAHN, where routing of cognitive users (CUs) is accomplished within CUs, in this proposed protocol, some of the primary users (PUs) support CUs to communicate, by forwarding CU packets. This service provided by PU is of voluntary nature. However, such assistance shall be provided by the PUs, only when they are idle, thereby, preserving the principles of cognitive radio networks (CRNs), which indicates that the operation of PU should not be disturbed by the CU activities. The proposed work is compared with cognitive ad hoc on‐demand distance vector (CAODV) protocol. The performance parameters considered are routing overhead, rate of loss of packets, and e2e packet delay. PSR outperforms CAODV in all these performance parameters. There has been on average 26.25% improvement in routing overhead, 34.12% decrease in loss, and 27.01% improvement in e2e delivery in the proposed PSR.

WITHDRAWN: Implementation of QOS metrics in Multi-hop cognitive radio routing protocol in heterogeneous environment

Abstract With the benefit of have privileged spectrum utilization efficiency, this network are quickly adapt for the provisioning of high qos contribution within wireless network. The cognitive based network, has specified a higher opportunity of receiving huge throughput giving a provision of high qos provisioning for the subsequently generation upcoming services In addition, the routing metrics use in multi-hop CRMANETs be supposed to reproduce the band ease of use, the links eminence, The PU behavior and quality of service (Qos) Necessities of secondary users. In favor of the most excellent of awareness, numerous of researchers investigate the presentation of the diverse routing protocols in a homogeneous surroundings only. In this article, we suggest a heterogeneous cognitive radio routing protocol (HCR) Ope Rates In Heterogeneous Environment (Organized Into Hierarchical Clusters). The projected routing protocol is suspiciously developed to formulate a substitution linking the channel diversity of the routing path next to with the CRMANETs throughput. With simulation, we talk about the performance of the future HCR routing protocol and evaluate it with the AODV routing protocol by means of a MATLAB simulation.

Spectrum-aware cross-layered routing protocol for cognitive radio ad hoc networks

Cognitive radio network has been proposed as a promising technology to satisfy the manifold requirements of future generation (5G) wireless system by intelligently accessing the underutilized channel of a primary user. However, due to the heterogeneity in channel propagation characteristics, intermittent availability of licensed channel, recurrent hand-offs, and need of a protection to primary users, finding a successful route is more challenging. Also, incorporation of opportunistic spectrum access in cognitive radio network requires a potential spectrum management functions across the network layers. Hence, a cross-layered channel assignment algorithm and routing algorithm is proposed for a cognitive radio ad hoc network which can overcome above-mentioned challenges and provide a stable path for routing of data packets. A novel metric, for the probability of successful transmission of a channel is derived by considering channel statistics, sensing periodicity of the cognitive user, and time-varying channel quality. Also, the number of available channels and their characteristics is considered for the selection of a next-hop node with an aim to avoid the one-hop neighbors located in the PU transmission range. The proposed routing protocol is simulated in ns-2 and compared with the existing similar protocols. The performance shows that the proposed algorithm performs better in terms of throughput, end-to-end delay, number of spectrum hand-offs, and interference to the primary user in a significant manner.

A Survey on Routing Protocols for Delay and Energy-Constrained Cognitive Radio Networks

The ever-growing demand for higher network data rates, lower delay, and conservative energy consumption at reduced costs, to support Internet-of-things (IoT) communications, has pushed wireless technologies into a new frontier. The growing demand for such technologies can be attributed to several factors, such as the massive number of the upcoming bandwidth-hungry IoT applications and the enormous number of - often battery-powered - devices expected to connect to the network. Cognitive Radio Networks (CRNs) can play a significant role in future generations of mobile-communication technologies by providing dynamic access to underutilized licensed bands. However, battery-operated devices, which communicate delay-sensitive data over multihop links, impose serious energy-delay limits. In such CRN-based IoT communications, as one device depletes its energy, network disconnectivity may arise, which can degrade the network efficiency. Therefore, building a reactive routing protocol to recover from any sudden link breakage is necessary to maintain prolonged network connectivity. This paper provides a comprehensive survey of CRN routing protocols that are based on two essential metrics, namely, packet delay, energy consumption, or both, while excluding all other CRN routing protocols. The survey is meant to support the designers of future CRN-based IoT communication frameworks with a detailed comparative survey, which targets the most relevant proposed routing protocols, including the specifics of the routing metrics, implemented spectrum awareness strategy, and employed medium-access control standard along with the simulator tool used for performance evaluation. In addition, this survey finds that the majority of cognitive radio routing protocols address either delay or energy consumption, but only a few consider a joint delay-energy metric, which suits delay-sensitive IoT applications running on energy-constrained devices.

An efficient routing protocol for cognitive radio networks of energy-limited devices

In the era of Internet-of-things (IoT), the future 5G networks are supposed to provide ubiquitous connectivity, high speed, as well as low latency and energy efficiency at low cost to billions of battery-powered wireless devices. The anticipated tremendous demand for wireless bandwidth in 5G networks calls for efficient usage of the underutilized licensed frequency spectrum that preserves the energy consumption of these energy-limited devices. This is feasible by embracing the cognitive radio concept and making use of its functionalities and capabilities to form 5G-CR incorporation. As a step towards this goal, an efficient routing protocol for cognitive radio (ERCR) networks is proposed in this paper. The proposed protocol is location-based and can fully operate over a single wireless channel using a channel access mechanism that follows the IEEE 802.11 distributed coordination function. It selects the route with the minimum number of forwarding nodes that have sufficient remaining energy. This, in turn, increases the per-node capacity to meet the operational requirements of different IoT applications. Meanwhile, it conserves the limited energy of battery-powered devices. The efficiency of the proposed protocol has been evaluated using extensive network simulator-2 computer simulations for a wide range of performance metrics under different activity levels of licensed users in terms of channel occupancy likelihood and duration. The simulation results reveal that ERCR is capable of providing reliable packet delivery at a low packet transfer latency while saving the energy of the cognitive radio network nodes with a fairly small overhead.

Classification of Routing Protocols Based on Routing Metrics in Cognitive Radio AD HOC Networks

Cognitive radio ad hoc networks are opportunistic networks, which utilize licensed spectrum. The spectrum assigning authority has divided the spectrum in to two regions: licensed and unlicensed. The unlicensed bands are clogged while licensed bands are underutilized. So unlicensed traffic needs to be shifted to unused licensed portion of the spectrum. Henceforth, Cognitive Radio Networks are proposed. These networks were having an infrastructure just like base station in cellular network. Cognitive radio ad hoc network are special wireless ad hoc networks having cognitive capability. In these networks, devices are able to adapt according to the environment. These devices are designed to operate in different frequency ranges. Routing data in this kind of network is a bit challenging due to its different nature. This paper discusses these challenges in detail. Later a detailed discussion is presented on the existing approaches used to handle these challenges. A clear & concise analysis of every approaches is preformed which leads to identification of merits & demerits of each of these approach. Lastly, identification of various routing metrics which need to be considered while designing a new routing protocol for cognitive radio ad hoc networks has been made.

Performance Modeling of Bio-Inspired Routing Protocols in Cognitive Radio Ad Hoc Network to Reduce End-to-End Delay

Performance modeling of bio-inspired routing protocols in cognitive radio ad hoc network to reduce end-to-end delay - The rapid

CROP: Cognitive radio ROuting Protocol for link quality channel diverse cognitive networks

Cognitive Radio is an emerging technology to overcome the problem of spectrum scarcity and underutilization. The vital requirement of Cognitive Radio Networks is quick route maintenance because of dynamic changing environment due to immediate emergence of Primary Users. The other major issue is the selection of path based upon shortest path or minimum hop while neglecting the Quality of the Links. The ultimate goal of routing metric is to choose a path that provides high throughput between the two end nodes, which is not possible as shortest path algorithm does not perform well in Multi-channel heterogeneous Cognitive Networks. Moreover, in multi-channel cognitive radio network the concatenated links between the nodes also deteriorates the overall network performance. In this paper Cognitive radio Routing Protocol (CROP) is proposed for ad-hoc networks, which emphasis on these three major routing problems and provides solution for the same. The key novelty of this proposed routing protocol (CROP) are Smart Spectrum Selection (SSS) and Succeeding Hop Selection (SHS) methods. These methods allow the selection of available spectrum by the relay node in a single process and thereby make the route formation a simple process and even reduces the routing overhead. This not only quickens the spectrum sensing and selection but also enhances the throughput due to reduced overheads. Simulative analysis shows the performance of the proposed protocol in the various environmental conditions. Comparative analysis of the proposed metric is also performed, which shows that the Proposed CROP outperforms the available competing Cognitive Radio routing protocols.

Joint channel assignment and routing protocol for cognitive radio ad hoc networks

Conventional single channel wireless ad hoc networks usually suffer from low network throughput owing to the higher number of packet transmissions required for multi-hop communication. Using multiple channels within a single network can improve the network throughput. In multi-channel communication networks, the channels must be assigned appropriately to maximise network performance. Existing channel assignment methods are usually based on the approach of interference reduction/minimisation, for example, by making a link to operate on only one channel and different links to operate on different channels. In this paper, we go in the opposite direction and propose to make links to operate on more channels. A new distributed joint channel assignment and routing protocol for cognitive radio ad hoc networks called cognitive radio-enhanced AOMDV is proposed. Simulation studies showed that our method outperforms other methods.

On-Demand Hybrid Routing for Cognitive Radio Ad-Hoc Network

A novel on-demand cluster-based hybrid routing protocol for cognitive radio ad hoc network with non-uniform node distribution is proposed in this paper. At first, a novel spectrum-aware clustering mechanism is introduced. The proposed clustering mechanism divides node into clusters based on three values: spectrum availability, power level of node, and node stability. Therefore, clusters are formed with the highest stability to avoid frequent reclustering. Later, a routing algorithm is introduced to minimize the delay while achieving acceptable delivery ratio. In this paper, routing is defined as a multi-objective optimization problem to combine different individual routing metrics to form a global metric. Simulation results show that our proposed routing algorithm can guarantee a lower delay and a higher packet delivery ratio than conventional routing protocols for cognitive radio ad hoc networks. Due to our routing design specification, such as power consideration and low delay, it can be suitable to be adopted for Internet of Things applications.

Eigenvector centrality-based stable path routing protocol for cognitive radio ad hoc networks

We propose to use eigenvector centrality (EVC) as the basis for determining stable paths and arrive at benchmarks for the number of path transitions incurred with stability-based routing in cognitive radio ad hoc networks (CRAHNs) wherein secondary users (SUs) use the available (idle) licensed channels of primary users (PUs). We model a time-variant network graph (at any time instant) of SU nodes whose adjacency matrix indicates the number of common available PU channels in the mutually intersecting neighbourhoods of any two SU nodes at the time instant. Such an adjacency matrix is used as the basis to compute the EVC of the vertices in the network graph of SU nodes and determine an end-to-end source-destination path whose constituent SU nodes have a higher EVC. Simulation results indicate EVC-based paths between any two SU nodes incur significantly fewer transitions without any appreciable increase in the average hop count per path.

A delay‐centric parallel multi‐path routing protocol for cognitive radio ad hoc networks

AbstractIn this paper, we develop a delay‐centric parallel multi‐path routing protocol for multi‐hop cognitive radio ad hoc networks. First, we analyze the end‐to‐end delay of multi‐path routing based on queueing theory and present a new dynamic traffic assignment scheme for multi‐path routing with the objective of minimizing end‐to‐end delay, considering both spectrum availability and link data rate. The problem is formulated as a convex problem and solved by a gradient‐based search method to obtain optimal traffic assignments. Furthermore, a heuristic decentralized traffic assignment scheme for multi‐path routing is presented. Then, based on the delay analysis and the 3D conflict graph that captures spectrum opportunity and interference among paths, we present a route discovery and selection scheme. Via extensive NS2‐based simulation, we show that the proposed protocol outperforms the benchmark protocols significantly and achieves the shortest end‐to‐end delay. Copyright © 2015 John Wiley & Sons, Ltd.

SEER: spectrum- and energy-efficient routing protocol for cognitive radio ad hoc networks

Cognitive radio ad hoc networks (CRAHNs) were developed to improve the utilization ratio of licensed spectrum. Since spectrum opportunities for users are varied over time and location, enhancing the spectrum effectiveness is a goal and also a challenge for CRAHNs. Besides, due to the energy limitation of the devices in CRAHNs, energy efficiency is another goal to be achieved. Therefore, the objective of this paper is to design a spectrum- and energy-efficient routing (SEER) protocol for CRAHNs, which improves transmission efficiency and balances energy consumption. The design of the protocol uses the techniques of expected transmission power, expected residual lifetime and utility indifference curves. The protocol will select the optimal route from all candidate paths. We present a performance comparison with two existing protocols for CARHNs: the minimum total transmission power (MTTP) and the min---max battery cost (MMBC) protocols. Simulation results show that SEER can reduce energy consumption by almost 40 % than that of MMBC, and increase network lifetime by almost 200 % than that of MTTP. Besides, SEER can improve the network throughput by at least 50 % and 150 % than that of MTTP and MMBC respectively.

Joint Channel Assignment and Routing Protocol for Cognitive Radio Ad Hoc Networks

Conventional single channel wireless ad hoc networks usually suffer from low network throughput owing to the higher number of packet transmissions required for multi-hop communication. Using multiple channels within a single network can improve the network throughput. In multi-channel communication networks, the channels must be assigned appropriately to maximise network performance. Existing channel assignment methods are usually based on the approach of interference reduction/minimisation, for example, by making a link to operate on only one channel and different links to operate on different channels. In this paper, we go in the opposite direction and propose to make links to operate on more channels. A new distributed joint channel assignment and routing protocol for cognitive radio ad hoc networks called cognitive radio-enhanced AOMDV is proposed. Simulation studies showed that our method outperforms other methods.

Mobility assisted spectrum aware routing protocol for cognitive radio ad hoc networks

We propose a mobility assisted spectrum aware routing (MASAR) protocol for cognitive radio ad hoc networks (CRAHNs), providing robustness to primary user activity and node mobility. This protocol allows nodes to collect spectrum information during a spectrum management interval followed by a transmission period. Cognitive users discover next hops based on the collected spectrum and mobility information. Using a beaconless mechanism, nodes obtain the mobility information and spectrum status of their neighbors. A geographical routing scheme is adopted to avoid performance degradation specially due to the mobility of the nodes and the activity of the primary users. Our scheme uses two approaches to find either short or stable routes. Since mobility metrics have a significant role in the selection of the next hop, both approaches use a reactive mobility update process assisted by mobility prediction to avoid location errors. MASAR protocol performance is investigated through simulations of different scenarios and compared with that of the most similar protocol, CAODV. The results indicate that MASAR can achieve significant reduction in control overhead as well as improved packet delivery in highly mobile networks.

Spectrum-aware routing in discontinuous orthogonal frequency division multiplexing-based cognitive radio ad hoc networks

With the rapid requirement and development of the green ICT (Information and Communication Technology) technology, the demand for dynamically radio spectrum resources has significant attention. The low utilisation of licensed spectrum leads to the scarcity of the spectrum resource. The emerging cognitive radio (CR) systems become increasingly important in the wireless green communication. In cognitive radio ad hoc networks, unlicensed users (called secondary users, SUs) communicate with other CR users through an ad hoc connection on licensed spectrum bands, but spectrum bands may be unexpectedly preempted by licensed users (called primary users, PUs). The design of routing protocol for CR ad hoc network considers problems of the dynamic spectrum sensing, management, sharing and mobility caused by reappearance of PUs. In this paper, the authors developed a spectrum-aware routing protocol for discontinuous orthogonal frequency division multiplexing-based cognitive ad-hoc networks by using the concept of the minimum expected total transmission time. With the expected total transmission time of all possible paths, a route with the smallest expected total transmission time is constructed. Mathematical analysis and simulation result illustrate that the proposed routing protocol can significantly reduce the total transmission time and improve the throughput.

Agile Spectrum Mobility Aided Spectrum-Aware Routing Protocol for Cognitive Radio Ad Hoc Networks

In this paper, a Spectrum-Aware Routing (SAR) protocol for cognitive radio ad hoc networks, (CRAHN), is proposed which is robust to primary user activity and node failures. The protocol allows nodes to collect spectrum information during a spectrum management interval followed by a transmission period. Cognitive users discover routes by joint channel and next hop selection (synchronization) in the transmission intervals. A restricted geographical routing approach is adopted to avoid performance degradation specially due to routing overhead. We also add spectrum mobility capabilities to routes in our proposed method to provide robustness to primary user activity. SAR protocol performance is investigated through simulations of different scenarios and is compared with the most similar work, CAODV protocol. The results indicate that SAR can achieve significant reduction in control overhead as well as improved throughput.

Energy-aware routing protocol for cognitive radio ad hoc networks

Routing is one of the most important issues in multihop ad hoc networks. In the routing for mobile cognitive radio (CR) networks, the constraints on residual energy of each user and the requirements for primary user protection should be additionally taken into account. This study proposes a spectrum and energy-aware routing (SER) protocol for CR ad hoc networks, which is based on the dynamic source routing. To establish routes on-demand with reserved bandwidth, the protocol involves route selection and channel-timeslot allocation jointly. The proposed SER protocol can balance energy consumption, reduce routing overhead, eliminate contention between nodes and decompose traffics over different channels/timeslots. Extensive simulation shows that the proposed protocol achieves good performance in system throughput, network lifetime and mean message delay.

CRP: A Routing Protocol for Cognitive Radio Ad Hoc Networks

Cognitive radio (CR) technology enables the opportunistic use of the vacant licensed frequency bands, thereby improving the spectrum utilization. However, the CR operation must not interfere with the transmissions of the licensed or primary users (PUs), and this is generally achieved by incurring a trade-off in the CR network performance. In order to evaluate this trade-off, a distributed CR routing protocol for ad hoc networks (CRP) is proposed that makes the following contributions: (i) explicit protection for PU receivers that are generally not detected during spectrum sensing, (ii) allowing multiple classes of routes based on service differentiation in CR networks, and (iii) scalable, joint route-spectrum selection. A key novelty of CRP is the mapping of spectrum selection metrics, and local PU interference observations to a packet forwarding delay over the control channel. This allows the route formation undertaken over a control channel to capture the environmental and spectrum information for all the intermediate nodes, thereby reducing the computational overhead at the destination. Results reveal the importance of formulating the routing problem from the viewpoint of safeguarding the PU communication, which is a unique feature in CR networks.

Search: A routing protocol for mobile cognitive radio ad-hoc networks

Recent research in the emerging field of cognitive radio (CR) has mainly focussed on spectrum sensing and sharing, that allow an opportunistic use of the vacant portions of the licensed frequency bands by the CR users. Efficiently leveraging this node level channel information in order to provide timely end-to-end delivery over the network is a key concern for CR based routing protocols. In addition, the primary users (PUs) of the licensed band affect the channels to varying extents, depending on the proportion of the transmission power that gets leaked into the adjacent channels. This also affects the geographical region, in which, the channel is rendered unusable for the CR users. In this paper, a geographic forwarding based SpEctrum Aware Routing protocol for Cognitive ad-Hoc networks (SEARCH), is proposed that (i) jointly undertakes path and channel selection to avoid regions of PU activity during route formation, (ii) adapts to the newly discovered and lost spectrum opportunity during route operation, and (iii) considers various cases of node mobility in a distributed environment by predictive Kalman filtering. Specifically, the optimal paths found by geographic forwarding on each channel are combined at the destination with an aim to minimize the hop count. By binding the route to regions found free of PU activity, rather than particular CR users, the effect of the PU activity is mitigated. To the best of our knowledge, SEARCH takes the first steps towards a completely decentralized, CR routing protocol for mobile ad-hoc networks and our approach is thoroughly evaluated through analytical formulations and simulation study.