Revive Exhausted Mobile Backhaul Fiber Links with CWDM and DWDM

The proliferation of data-hungry mobile devices is driving a seemingly insatiable need for mobile backhaul bandwidth. Fiber is the only media capable of supporting virtually limitless growth, so Carriers are currently driving fiber to the edges of the network. Coarse Division Wavelength Multiplexing (CWDM) is a cost-effective and reliable method to expand the fiber capacity of mobile backhaul networks and Radio Access Networks (RAN).

Mobile Backhaul Products

Multiple 3G and 5G/LTE Services over CWDM Mobile Backhaul

This application example demonstrates how to deploy iConverter CWDM/X Multiplexers and CWDM/AD Add Drop Multiplexers to expand the capacity of mobile backhaul fiber access networks.

On the left side of the diagram is a high-density 19-Module Chassis populated with iConverter 8-Channel CWDM/X Multiplexer modules located at a Mobile Switching Center (MSC). Each CWDM/X module has eight channel ports, and each channel port connects to a GM4 Network Interface Device (NID), or a T1/E1 and Ethernet Multiplexer (services from these devices are listed in the call out on the bottom left). The NIDs provide Gigabit Carrier Ethernet backhaul for 5G/LTE services, and the T1 Multiplexers transports up to sixteen T1s and Gigabit Carrier Ethernet for 3G services. Each of the NIDs and T1 Multiplexers are equipped with CWDM SFP Transceivers that match the wavelength of the CWDM/X channel ports, and are connected to the channel ports with fiber patch cables (color coordinated in the illustration for each wavelength).

Each fiber strand (Common Fiber Link) from the MSC transports 8 CWDM channels that connect to four cell towers with a 3G and 5G data channels connected to each cell tower. 16 channels can be transported over each fiber strand when two 8-Channel CWDM/X modules are connected with an optional Band Splitter, and each channel can support a data rate up to 10G.

An iConverter 2-Channel CWDM/AD Add+Drop Multiplexer is located at each tower along a fiber daisy chain (bus topology). Each CWDM/AD filters out two of the appropriate channels (wavelengths) at each tower. The other channels pass through the CWDM/AD Multiplexer and daisy chain to the next Add+Drop location.

At the each cell tower (shown in the call out on the bottom right), one wavelength transports sixteen T1s and Carrier Ethernet for 3G services, and is connected to a Modular T1/E1 Multiplexer with a GM4 NID transport module equipped a 1510nm SFP transceiver. The other data channel is transporting Carrier Ethernet for the 5G/LTE service, and is connected to an iConverter GM4 NID with a 1530nm CWDM SFP transceiver. The GM4 NID provides performance monitoring, fault management, and timing synchronization for the 5G/LTE service.