公开(公告)号：US20250047518A1

公开(公告)日：2025-02-06

申请号：US18792054

申请日：2024-08-01

Applicant: Applied Optoelectronics, Inc.

Inventor： Rafael CELEDON ,  Yi WANG ,  Tina MATHEWS ,  Ruru CHEN ,  Mark SIEJKA ,  Hang XIE ,  Ramesh NALLUR ,  Stefan MURRY ,  David STEWART

IPC: H04L12/28 ,  H04B1/69

Abstract: Low data rate, low power, bi-directional transmissions may be provided over existing physical communication media (e.g., coaxial cables) using a portable network communications module and in the presence of higher bandwidth, higher power primary signals currently being transmitted over the communication media. The low data rate, low power, bi-directional transmissions may be accomplished using spread-spectrum modulated signals that are positioned in frequency relative to the primary signals, such that the low data rate, low power transmissions occur without detectable interference with the primary signals, which include multiplexed narrowband modulated signals. The primary signals may be modulated using quadrature amplitude modulation (QAM) and multiplexed using orthogonal frequency division multiplexing (OFDM) and the spread-spectrum modulated signals may be chirp spread spectrum (CSS) modulated signals modulated using Gaussian frequency shift keying (GFSK). One example of the spread-spectrum modulated signals is implemented using LoRa technology and communication protocols defined by the LoRaWAN standard.