With the acceleration of 5G deployment, how to construct the 5G network in a cost-effective and efficient way has become a hot topic. In this situation, sharing the abundant infrastructure of FTTx networks can be an alternative option for the operators in the 5G era. For one thing, since the Sub-6GHz frequency band is leveraged in standalone networks, the number of required 5G macro cells will be huge, which is estimated to be 1.2 to 2 times of that in the 4G era. Coupled with the separated architecture of AAUs and DUs, fiber resources become pivotal to network deployment. The fiber density of the deployed ODN networks is at least ten times the fiber density required by 5G, allowing for economical and rapid access to 5G AAUs. For another, in the newly built 5G covered areas or hotspot areas, the location of DUs has been taken into account. Deploying DUs with OLTs in the access office can effectively reduce total costs, including rental and new network construction costs as well as DU site maintenance costs.
To meet the requirements in 5G fronthaul deployment, ZTE proposed the Combo PON Plus solution, a further innovation based on ZTE’s Combo PON solution. ZTE unveiled the industry’s first Combo PON solution in the year of 2016, which achieves smooth migration from GPON to 10G-PON. At present, ZTE Combo PON solution has been put into commercial use worldwide. Based on Combo PON, the Combo PON Plus solution fully makes use of the existing FTTx infrastructure resources, allowing fixed and mobile network to share the infrastructure resources, and providing stable and reliable dual-gigabit access of FTTx and 5G to end users.
- Combo PON Plus Solution
In the Combo PON Plus solution, the innovative Combo PON Plus line card supports five wavelength channels per port. Among which, two wavelength channels are used for GPON and 10G-PON respectively to provide two FTTx access rates, allowing for smooth migration from GPON to 10G-PON through flexible replacement of ONUs. The other three wavelength channels are used for one 25G WDM wavelength respectively to provide a bandwidth of 25Gbps, connecting three AAUs for 5G fronthaul. Through the independent wavelength stacking mechanism, the Combo PON Plus solution innovatively supports simultaneous FTTx and 5G fronthaul over the same feeder fiber, and implements rapid deployment of 5G services.
11.Analysis of Combo PON Plus Solution Application Scenario
The Combo PON Plus solution is mainly suitable for the FTTx and 5G macro cell deployment at the same time in the areas with abundant fixed fiber resources. The GPON and 10G-PON channels ensures the legacy FTTx access services. The three 25G WDM wavelength channels under the Combo PON Plus port connects one AAU respectively for 5G macro cell to provide mobile services.
111.FMC for Shared Resources
The Combo PON Plus solution supports 5G deployment by fully making use of the existing FTTx network resources including the idle access offices, ODFs, power supply and temperature control systems, feeder fibers and ducts, distribution fibers and ducts, as well as roadside and outdoor cabinets. It meets the operators’ requirements for massive fiber and equipment room resources in the 5G buildout process. Take the feeder fiber requirement during the 5G deployment as an example: In a typical scenario, an access office connects 18 AAUs, the traditional point-to-point direct fiber connection needs 18 new feeder fibers since each fiber only transmits one wavelength, and the passive CWDM solution needs 6 new feeder fibers since each fiber transmits three wavelengths. However, the Combo PON Plus solution only needs to share 6 feeder fibers in legacy network, without any influence on existing FBB services. Compared with the traditional point-to-point direct fiber connection solution and the passive CWDM solution, the Combo PON Plus solution can effectively reduce 5G deployment costs and shorten the time to market, helping operators build a comprehensive service access area with the goal of resource sharing and cost-effective network construction.
ZTE has been exploring in the FMC field for years, and helping deploy mobile services rapidly by sharing fixed network resources. ZTE has helped Telkom Indonesia build the world’s largest 2G/3G/4G FTTM network. In the 5G era, ZTE continues to innovate and proposes the Combo PON Plus solution, providing stable and reliable dual-gigabit access of FTTx and 5G to users and promoting the development of 5G services economically and efficiently based on the massive ODN fiber resources in existing networks.