To achieve both redundancy of a transmission line and cost-effectiveness in the event of failure, we previously proposed a cost-effective redundant mobile fronthaul (MFH) system that uses only a short-reach transceiver. In this paper, we present a prototype that implements a rate-adjustment function for adjusting the data rate in accordance with the parity amount of the FEC as the MFH redundancy function. To evaluate the feasibility of our system, we demonstrate the results of the processing delay and budget-expansion effect when the parity amount of the forward error correction (FEC) Reed-Solomon is changed in the prototype under MFH burst traffic conditions.
This paper examines the possibility of an electromagnetic interference (EMI) caused by unintentional radiated emissions from an unshielded twisted pair (UTP) cable in the sub-6GHz band of 5G. First, it is experimentally and numerically confirmed that a UTP cable with a twist pitch of 20mm and a sheath with relative permittivity of 2.9 radiates above 5.7GHz. It is also clarified that the radiated emissions are attributable to the twist structure. In addition, the usefulness of two equations, derived in developing radiating pair cables, to easily calculate the radiation band and the radiation angle to solve the EMI problem is validated.
This letter proposes a windowed-based error correction scheme for spatially coupled low-density parity-check (SC-LDPC) codes over channels with insertion and deletion errors. We first introduce the windowed detection and decoding scheme and then examine its asymptotic performance with several types of SC-LDPC codes. Subsequently, we demonstrate that a significant performance gain with lower latency and delay can be obtained using finite-length SC-LDPC codes.
FPGA virtualization using container (FPGA container) are being used to implement cloud services as the combinations offer high-speed processing. As it is necessary to migrate FPGA container to another server due to system maintenance etc., this paper proposes an integrated system of managing FPGAs and containers using OSS such as k8s and Tacker. Experiments show that the proposed system can detect the specified migration trigger and automatically perform FPGA container migration between servers.
For rapid service creation, software-defined network (SDN) controller is promising when establishing access networks on the all-photonics network (APN). To our knowledge, no study has investigated fast restoration from SDN controllers with NETCONF/RESTCONF for high-reliability service requirements. This paper proposes an automatic fast failure restoration application on a software-defined optical switch controller with NETCONF/RESTCONF. It includes periodic device information collection and failure detection with optical power information via the SDN controller. Evaluations show that our application achieves 0.9-s failure restoration in a system that uses an optical switch and a server with SDN controller.
A simple technique based on the substitution method is proposed to measure the radiation efficiency of an antenna in a reverberation chamber. The substitution method requires a reference antenna with a known radiation efficiency, which is composed of ohmic and dielectric losses and is usually difficult to measure. In the proposed method, a waveguide to coax adapter is used as the reference antenna. The radiation efficiency of this adapter can be easily and accurately measured as insertion loss by connecting it directly to a vector network analyzer. The radiation efficiency of a WR-42 pyramidal horn antenna with the frequency band of 18GHz to 26.5GHz was determined by the proposed method.
Before performing electromagnetic interference (EMI) measurement tests in the frequency range below 30 MHz, the test site must be evaluated by normalized site insertion loss (NSIL) using a pair of loop antennas. The site insertion loss measurements are performed with three arrangements of loop antennas to measure three-axis components of magnetic fields in the near-field regions. In this paper, it is shown that the locations of the feed gaps on the loop antenna elements change the values of the SIL. The preferable locations of the feed gaps are proposed to perform the NSIL measurements with the measurement results in a semi-anechoic chamber.