USource Passive WDM Solutions for 5G xHaul RAN
One of the main challenges in dense 5G xHaul radio access networks (RANs) is the provisioning of low-cost connectivity between a large number of antennas, located at remote sites, and a central site (hub) in which baseband processing functions are performed. The wavelength division multiplexing (WDM) is the principal transport network technology enabling the reduction of the demand for direct optical fiber connections of fronthaul (between RU and DU), midhaul (between DU and CU), and backhaul (between CU and a 5G core network).
WDM makes it possible to establish a number of such links, using different wavelengths in a single optical fiber. Additional savings by reducing the number of fibers required can be achieved by means of optical add-drop multiplexers (OADMs). OADMs enable the access of unused wavelengths by intermediate remote nodes, whenever the capacity on the WDM system is not fully utilized by the end remote node.
USource Offers Passive WDM Solutions
Different solutions have been considered for passive WDM networks. Coarse Wavelength Division Multiplexing (CWDM) has been widely used in local and metropolitan networks. In CWDM, the channel spacing equals 20 nm, which enables the use of 18 channels in the wavelength range from 1271 nm to 1611 nm. Due to the wide range of dispersion, CWDM has limited use in systems with an extreme bit rate of 100 Gb/s per wavelength. Zero dispersion of the G.652D fiber lies in the range of 1312±12 nm. For this reason, in the IEEE 802.3cu standard, the wavelength range is limited to 4 channels: 1271, 1291, 1311, and 1331 nm. In China, the range has been expanded to 6 channels 1271 to 1371 nm.
A two times denser spacing (that is 10 nm) was proposed in the Metro Wavelength Division Multiplexing (MWDM) system. Twelve (12) channels were located in the range from 1267.5 to 1374.5 nm. In addition, 12-channel LAN-WDM system (LWDM) with an 800 GHz inter-channel spacing is used, which in the O-band window corresponds to a spacing of about 4.5 nm. The center of channels passband equals, respectively, 1269.23, 1273.55, 1277.89, 1282.26, 1286.66, 1291.10, 1295.56, 1300.05, 1304.58, 1309.14, 1313.73, and 1318.35 nm.
In the mentioned WDM systems, multiplexers (MUX), demultiplexers (DMUX), and add/drop modules (OADM), which utilize optical thin-film filters (TFF), are used to extract a channel of a specific wavelength. They have better transmission properties than Bragg grids (FBG) and array waveguide gratings (AWG), especially with inter-channel spacing greater than 200 GHz.
USource Technology Products
USource Technology manufactures fiber optic devices and optical communication products. The company has two business groups, optical active manufacturing and optical passive manufacturing. USource fiber optics products and optical networking solutions are widely used in data centers, FTTX, ethernet, video transmission, metro networks, base stations, etc. The optical active manufacturing group produces optical sub-assemblies (TOSA, ROSA, BOSA, Triplexer), optical transceivers (SFP, XFP, QSFP), media converters and switches. The optical passive manufacturing group provides micro-optic components, CWDM & DWDM multiplexers, fiber splitters, cable connectors, and assemblies.
To request more information or a quotation for any USource Technology products, contact IL Photonics.