Hybrid Ring- and Tree-Topology RoF Transmission System with Disconnection Protection

This paper proposes a hybrid ring- and tree-topology radio over fiber (RoF) transmission system with self-disconnection protection that can support the high distribution density of base stations (BSs) in a metropolitan area and strengthen the network quality of service through self-disconnection protection. The number of supportable BS in the system can be increased significantly by integrating the time- and wavelength-division multiplexing techniques and properly utilizing a new-generation single-line bidirectional add/drop multiplexer (SBOADM) into the proposed system. Moreover, when the ring–fiber link of the system is interrupted for any reason, the system operator can recover the broken connections quickly only by transforming an optical switch state at the CO end to allow the downlink optical signals to transmit along the clockwise and counterclockwise directions of the ring–fiber link simultaneously. In this case, the downstream optical signals can be delivered to each set of BS-groups through the two-way transmission characteristics of the SBOADM automatically, and the uplink optical signals, originally, from each set of BS-groups can be transmitted back to the CO end along the opposite direction of the downlink signal-routing path. In this way, the interference caused by fiber breakage can be avoided immediately, and the entire transport system can be reconnected to ensure the quality of network services. Our experimental results prove that the overall transmission performances are similar to those under normal circumstances.

Pengujian QoS Pada Implementasi SDN Berbasis Mininet dan OpenDaylight Menggunakan Topologi Tree

The development of information technology and computer network from time to time is increasing along with the increase in user needs for both from the business, education, industrial, to data security side. Data of network traffic that is getting denser in communication and data exchange between users on computer networks can become a problem when using conventional computer network technology. For that, it needs a new technology that is implemented in computer networks, along with the measurement of Quality of Service (QoS) in it. Software-Defined Networking (SDN) is a solution for this, where the stages of network design, management and implementation, separate the data plane and the control plane. In this research, the implementation of SDN was carried out in the form of a simulation using both of Mininet and OpenDaylight with a Tree Topology, then the QoS measurements were carried out in it. The results of testing and measuring QoS on SDN simulations with Tree topology using Mininet and OpenDaylight, showed a Jitter value of 0.425 ms, a Packet Loss value of 0.266%, a Bandwith value of 9.3925 Mbps, a UDP Throughput value of 2.348 bits/sec, and a TCPThroughput value of 2.335 bits/sec.

pSONIC: Ploidy-aware Syntenic Orthologous Networks Identified via Collinearity

With the rapid rise in availability of high-quality genomes for closely related species, methods for orthology inference that incorporate synteny are increasingly useful. Polyploidy perturbs the 1:1 expected frequencies of orthologs between two species, complicating the identification of orthologs. Here we present a method of ortholog inference, Ploidy-aware Syntenic Orthologous Networks Identified via Collinearity (pSONIC). We demonstrate the utility of pSONIC using four species in the cotton tribe (Gossypieae), including one allopolyploid, and place between 75-90% of genes from each species into nearly 32,000 orthologous groups, 97% of which consist of at most singletons or tandemly duplicated genes – 58.8% more than comparable methods that do not incorporate synteny. We show that 99% of singleton gene groups follow the expected tree topology, and that our ploidy-aware algorithm recovers 97.5% identical groups when compared to splitting the allopolyploid into its two respective subgenomes, treating each as separate “species”.