Journal of High Speed Networks - Volume 24, issue 2

Authors: Falamarzi, Reza | Bahrambeigy, Bahram | Ahmadi, Mahmood | Rajabzadeh, Amir

Article Type: Research Article

Abstract: Software solutions are not effective to be used in network applications because of their low throughput. By employing hardware implementation on FPGA, not only sufficient flexibility is achieved but also the throughput is increased considerably. In this paper, two multi-core architectures are proposed for Bloom filter and CRC as two main network processing core functions. These architectures called multi-core architecture with shared queue and multi-core architecture with private queue. The proposed architectures are implemented for 1, 2, 4, 8 and 16 cores. Experimental results show that multi-core architecture with private queue achieves higher throughput In comparison to the other one. …As compared to Bloom filter, CRC application leads to less computational load and consequently more throughput. Moreover, Bloom filter is implemented on GPU and CPU and the results are compared with each other. When number of packets in GPU memory is 16384, the speedup achieved by GPU implementations using CUDA is about 274 times compared with CPU implementations. However, FPGA results outperform GPU, so that the throughput of the first architecture (shared queue) and second architecture (private queue) with 16 cores are almost 5.5 and 7.1 times higher than GPU throughput, respectively. Show more

Keywords: Bloom filter, Cyclic Redundancy Check (CRC), Field-Programmable Gate Arrays (FPGA), Graphics Processing Unit (GPU), Multi-core/many-core processors

DOI: 10.3233/JHS-180583

Citation: Journal of High Speed Networks, vol. 24, no. 2, pp. 89-106, 2018

Authors: Bylykbashi, Kevin | Spaho, Evjola | Barolli, Leonard | Xhafa, Fatos

Article Type: Research Article

Abstract: In this paper, we evaluate and compare the performance of different routing protocols in a many-to-one communication within a Vehicular Delay Tolerant Network (VDTN). Seven groups with three stationary sensor nodes sense the temperature, humidity and wind speed and send these data to a stationary destination node that collect them for statistical and data analysis purposes. Vehicles moving in Tirana city roads in Albania during the opportunistic contacts will exchange the sensed data to destination node. The simulations are conducted with the Opportunistic Network Environment (ONE) simulator. For the simulations we considered two different scenarios where the distance of the …source nodes from the destination is short and long. For both scenarios the effect of node density, ttl and node movement model is evaluated. The performance is analyzed using delivery probability, overhead ratio, average latency, average number of hops and average buffer time metrics. The simulation results show that the increase of node density increases the delivery probability for all protocols and both scenarios, and better results are achieved when shortest-path map-based movement model is used. The increase of ttl slightly affects the performance of all protocols. By increasing the distance between source nodes and destination node, delivery probability is decreased almost 10% for all protocols, the overhead for sprayandwait protocol does not change, but for other protocols is slightly increased and the average number of hops and average latency is increased. Show more

Keywords: Opportunistic network, DTN, VDTN, routing protocol, ONE Simulator

DOI: 10.3233/JHS-180584

Citation: Journal of High Speed Networks, vol. 24, no. 2, pp. 107-118, 2018

Authors: Dhurandher, Sanjay Kumar | Borah, Satya J. | Woungang, Isaac | Tibarewal, Suryansh | Barolli, Leonard

Article Type: Research Article

Abstract: Designing a routing protocol for opportunistic networks (OppNets) is a challenging task due to node’s mobility and the lack of further knowledge about the network topology and the presence or not of an end-to-end path. This paper proposes an energy efficient routing protocol called Distance and Encounter based Energy-Efficient Protocol (DEEP), in which the selection of the best next hop forwarder for a message relies on the node’s energy. Simulation results demonstrate that the proposed scheme outperforms E-Prophet, E-PRoWait and E-EDR, our energy-aware implementations of the Probabilistic Routing Protocol using History of Encounters and Transitivity (so-called Prophet), Probability-based controlled flooding …in opportunistic networks (so-called PRoWait), and Encounter and Distance based Routing (so-called EDR) routing protocol, in terms of node’s residual energy, number of dead nodes, message delivery probability, and message latency. Show more

Keywords: Opportunistic networks, Delay-Tolerant Network (DTN), Opportunistic Network Environment (ONE) simulator, E-Prophet, E-PRoWait and E-EDR

DOI: 10.3233/JHS-180585

Citation: Journal of High Speed Networks, vol. 24, no. 2, pp. 119-131, 2018

Authors: Alyatama, Anwar

Article Type: Research Article

Abstract: The rapid change in traffic behavior and the tremendous growth in bandwidth demand have promoted the development of a new generation of optical networks known as elastic optical networks (EONs). EONs provide scalable, flexible, and efficient assignment of network resources. Spectrum allocation is one of the most important factors in the success of EONs. In this study, we propose an adaptive spectrum allocation algorithm for EONs in the case of multicasting. The algorithm is based on relative cost and learning automata to produce a near-optimal searching sequence of the optical spectrum. The algorithm estimates the net margin of carrying a …call at a set of contiguous frequency slots on subsequent (future) call arrival. This margin will be used to sort the spectrum frequencies. Simulation results show that our algorithms outperform existing algorithms and provide savings for the normalized revenue loss of up to 50% over the static first-fit spectrum allocation algorithm. Show more

Keywords: Elastic optical networks, routing and spectrum allocation, learning automata, multicast

DOI: 10.3233/JHS-180586

Citation: Journal of High Speed Networks, vol. 24, no. 2, pp. 133-146, 2018

Authors: Fouziya Sulthana, S. | Nakkeeran, R. | Shaffath Hussain Shakir, S. | Rajesh, A.

Article Type: Research Article

Abstract: Multicasting is an effective method of transmitting the group messages that results in minimal utilization of network resources. But in real scenario, both unicast and multicast services are to be served by the evolved Node B (eNB). So an appropriate resource allocation method should be adopted to satisfy the Quality of Service (QoS) requirements of these services. This paper focuses on resource allocation method for Long Term Evolution (LTE) downlink when these services are scheduled by the eNB. To improve the system throughput, an objective function is formulated that maximizes the throughput of both unicast and multicast services. The multicast …group is in turn divided into subgroups and the subgrouping allocation is carried out by means of Genetic Algorithm (GA) that aims to maximize the total throughput. It is shown that multicast with subgrouping shows 20% increase in the total throughput and 3% reduction in average delay when compared with combined unicast and conventional multicasting method that uses Least Channel Gain (LCG) user rate for multicast transmission. Show more

Keywords: Multicasting, LTE, subgroup, genetic algorithm

DOI: 10.3233/JHS-180587

Citation: Journal of High Speed Networks, vol. 24, no. 2, pp. 147-159, 2018

Authors: Miao, Jingcheng | Song, Xiaoou

Article Type: Research Article

Abstract: In cognitive radio (CR) networks, it is crucial for secondary users to quickly detect spectrum holes when prior information of primary users is unknown. This paper proposes a new cooperative spectrum sensing (CSS) scheme based on nonparametric cumulative sum (NCUSUM) to reduce the mean detection delay under the condition of unknown prior information. The proposed scheme consists of secondary users and fusion center. Secondary users preprocess the observation data of spectrum to get positive drifts and negative drifts and only transmit positive drifts to fusion center. Fusion center uses the NCUSUM to accumulate positive drifts to make a fast decision …about whether the primary signal is present or not. To ensure the false alarm probability low enough, this scheme notes that the decision can be made in certain time interval. The simulation results show that the proposed cooperative spectrum sensing scheme has better performance in reducing mean detection delay with respect to conventional soft combination schemes. Show more

Keywords: Nonparametric cumulative sum, cognitive radio networks, soft combination, detection delay, spectrum holes, cooperative spectrum sensing

DOI: 10.3233/JHS-180588

Citation: Journal of High Speed Networks, vol. 24, no. 2, pp. 161-174, 2018