A system comprising a first optical line terminal (OLT) of a first passive optical network (PON) with the first OLT configured to receive user data from a baseband unit (BBU) and send the user data to a remote radio unit (RRU) via a first optical network unit (ONU) of the first PON using a first wavelength, and a second OLT of a second PON, the second OLT configured to obtain control and management (C&M) information, share the C&M information with the first OLT, and send the C&M information to a second ONU that is co-located with the first ONU using a second wavelength.

A bi-directional optical transceiver includes multiple single mode optical ports and a multi-mode optical port. A multi-mode optical combiner combines single mode optical signals received at the single mode optical ports into a multi-mode optical signal at the multi-mode optical port. Each single mode optical signal has a distinct optical mode that does not interfere with the optical mode of the other single mode optical signals. A photo detector detects a total optical power of the plurality of single mode optical signals in the multi-mode optical signal. An amplifier is coupled to receive an output of the photo detector.

An OLT configures combinations of wavelength pairs used for upstream and downstream signals, in a wavelength multiplexing optical communication system which performs single-core bidirectional transmission of a plurality of upstream and downstream signals, in such a way that the maximum value of the chromatic dispersion delay amount calculated from each wavelength pair is less than the maximum value of the chromatic dispersion delay amounts calculated when the combinations of wavelength pairs used for upstream and downstream signals are both allocated from the short wave side.

A laser light generator is configured to generate one or more wavelengths of continuous wave laser light. The laser light generator is configured to collectively and simultaneously transmit each of the wavelengths of continuous wave laser light through an optical output of the laser light generator as a laser light supply. An optical fiber is connected to receive the laser light supply from the optical output of the laser light generator. An optical distribution network has an optical input connected to receive the laser light supply from the optical fiber. The optical distribution network is configured to transmit the laser light supply to each of one or more optical transceivers and/or optical sensors. The laser light generator is physically separate from each of the one or more optical transceivers and/or optical sensors.

Example embodiments of a time division duplex (TDD) Wavelength Division Multiplex Passive Optical Network (WDM PON) architecture using passive optical splitters are disclosed herein. The disclosed TDD WDM PON includes fixed wavelength optical transmitters in an Optical Line Termination system with tunable receiver colorless Optical Network Units (ONUs) that reuse the downstream CW light to carry upstream data. The same wavelength may be used for downstream and upstream transmissions on a single fiber in the ODN. In this architecture, the number of ONUs may be greater than the number of transmitters at the OLT, allowing for a highly scalable system with capacity for growth. An example embodiment of the disclosed system uses Arrayed Waveguide Grating (AWG) or WDM filters at the OLT and a passive optical splitter in the field.

A multi-wavelength passive optical network (MW-PON) includes an optical distribution network (ODN), a plurality of optical line terminations (OLTs) and an optical network unit (ONU). The ODN includes a trunk fiber, one or more branching elements, and a plurality of distribution fibers. Each OLT is associated with an individual bi-directional wavelength channel using a corresponding single downstream wavelength and a corresponding single upstream wavelength, and supporting a specific downstream line rate and one or more distinct upstream line rates. The ONU is communicatively coupled to a respective distribution fiber, being tunable over a specific range of downstream wavelengths and a specific range of upstream wavelengths, and supporting a specific downstream line rate and a specific upstream line rate. The OLT is configured to assemble a broadcast management message conveying information about bi-directional wavelength channels in said MW-PON system and transmit said message downstream over the associated bi-directional wavelength channel.

A method of establishing communication between an optical line terminal and an optical network unit within an optical access network includes receiving a signal indication from an optical transceiver of an optical line terminal. The signal indication includes: (i) a loss-of-signal indication indicating non-receipt of an upstream optical signal from the optical network unit; or (ii) a signal-received indication indicating receipt of the upstream optical signal from the optical network unit. The method includes determining whether the signal indication includes the loss-of-signal indication. When the signal indication includes the loss-of-signal indication, the method includes instructing the optical transceiver to cease signal transmission from the optical transceiver to the optical network unit. Moreover, when the signal indication includes the signal-received indication, the method includes instructing the optical transceiver to transmit a downstream optical signal from the optical transceiver to the optical network unit.

A telecommunications system may include a measurement receiver to confirm the presence of a MIMO signal prior to decoding signals to avoid decoding spectrum that does not include MIMO signals. The measurement receiver may determine a fast Fourier transform (FFT) spectrum for asynchronous wideband digital signals received from two or more ports. The measurement receiver may determine an average FFT spectrum based on the determined FFT spectrum and identify a bandwidth of signals present in the average FFT spectrum. The measurement receiver may identify the MIMO signals present in the bandwidth of signals and decode only the identified MIMO signals.

An electrochemically active material is represented by general formula (I): Si.sub.uSn.sub.vM.sub.1wM.sub.2x[P.sub.0.2O.sub.0.8].sub.y.A.sub.z(I) where u, v, w, x, y, and z represent atomic % values and u+v+w+x+y+z=100, M.sub.1 includes a metal element or combinations of metal elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, B, carbon, or alloys thereof, M.sub.2 includes a metal element or combinations of metal elements selected from Mg, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, or alloys thereof, A is an inactive phase other than a phosphate or silicide, and 0<u<90, 0v<20, 0<w<50, 0<x<20, 0<y<20, and 0z<50.

A bi-directional optical transceiver includes multiple single mode optical ports and a multi-mode optical port. A multi-mode optical combiner combines single mode optical signals received at the single mode optical ports into a multi-mode optical signal at the multi-mode optical port. Each single mode optical signal has a distinct optical mode that does not interfere with the optical mode of the other single mode optical signals. A photo detector detects a total optical power of the plurality of single mode optical signals in the multi-mode optical signal. An amplifier is coupled to receive an output of the photo detector.