When discussing fiber infrastructure for cities, we mostly talk about “Gigabit Cities,” which are certainly the state of the art today. GPON or 10GPON are the way to provide gigabit FTTH, and DOCSIS-3 or RFOG can provide similar bandwidth for CATV systems. 5G and WiFi 6 wireless promise almost as much bandwidth, although they are still unproven.
But fiber-optic networks are good for 20-40 years at least, so what happens as time moves on? Is Gigabit good enough? Based on past history of the communications networks and the Internet, the answer is obvious, of course not. So doesn’t it make sense to design fiber optic networks today that will be good in the future – the Terabit future?
Graph of Internet speeds from Netly Fiber.
Another issue that makes sense is “open access.” If the owners of the fiber optic cable plant are not service providers, they can provide the connections to the users and allow multiple ISPs, CATV companies, telcos, etc. to colocate in their head end. If a customer wants to add or change service providers, only a simple patchcord change is needed. Open access networks are preferable for cities because it can allow more flexibility in offering services to citizens and for the city’s own uses.
Can networks like this be built today? That’s what a company called Netly Fiber has done in Solana Beach, CA. In June 2022, Netly completed their 2-year project of building a fiber network in Solana Beach that shows that with some forethought, you can build “Terabit” fiber-optic networks today that should be good for the lifetime of the fiber.
(An aside: When Jack Demers, an entrepreneur in wireless, got interested in fiber over 5 years ago, he called FOA asking questions. He came to our office and spent most of a day discussing the work we had done with FTTH, starting with helping Verizon with FiOS and our recent work in the DIY projects like Southern Fiberworx and Connect Anza. We discussed a lot of topics that day and since then we have continued our conversations as Netly has gotten started and begun operations. And, for full disclosure, your editor, JH, is a minor shareholder in Netly.)
What exactly is Netly doing that is different? The multi-million dollar project took two years to complete and includes ultra-high-speed dark fiber access for every residence, business, traffic light, and institution in the city. To achieve terabit speeds the Netly team took a bold approach and built multiple dedicated strands of fiber to each address located on city streets. Over 30,000 fibers are available for Solana Beach’s 6,000 households.
Yes, every user in the city can have dedicated fiber back to Netly’s head end. And the fiber network is open access; Netly is not an ISP, telecom or CATV company, they just provide the dark fibers and colocation space for service providers. Service providers locate their equipment at Netly’s head end, patch into their customers’ fibers and provide their services using whatever protocols they choose.
Service providers’ equipment (including splitters for PON networks) are placed in the Netly Edge Fiber Center (headend)
Does a centralized fiber infrastructure make sense? Most networks today are based on PONs, passive optical networks that use splitters to serve multiple users from a single network GPON OLT port over one fiber, with splitters placed along the network route. But will that architecture still work in a decade or two? Possible, as 10G is already here and 100G PONs using coherent transmission in R&D. And, then again, maybe not. In the future we may need direct connection to every user.
The centralized fiber network Netly uses is really cheap insurance for the future. If you are using GPON on Netly’s cable plant today, you put your OLT in their head end along with the PON splitters and connect to every user on their dedicated fiber. If the architecture changes to direct connection to the user in the future, a simple change of equipment is all that is needed.
Is centralized fiber affordable today? Netly thinks so. But they are utilizing state-of-the-art products and technologies.
Based on his analysis of the market and new developments in technology, Jack developed a unique business plan for Netly. The notion of centralized fiber with a connection to every user makes sense today because fiber is inexpensive and this architecture reduces the need for numerous fiber distribution hubs and pedestals for splitters or other equipment scattered around the service areas. And centralized fiber architecture is ready for terabit applications.
For the cities on the Southern California coast Netly was interested in, all were somewhat urban but mostly suburban in geography. Underground installation would be required in areas where aerial cables were not permitted, so using microtrenching made sense for the installation method. Working with Corning, Netly chose a microcable that could be blown into microducts. Each trench route has a microduct with six ducts in a row. When only one duct was used, 288 fibers in the microcable were available, but each route could be expanded to 6 of the 288 fiber microcables for 1728 fibers total.
Netly’s microtrenching technique deserves a mention also. Where possible, that is there are no conflicts with other buried utilities, they trench at the joint between the road pavement and the curb, minimizing damage to either. Drops are done in small handholes near the curb, leaving an installation that is almost undetectable. And installation is quick, making for minimal disruption in a neighborhood.
Besides a unique model for the FTTH cable plant, Netly has used a different model for their financing. Netly is funded by private investors who believe this is the best model for FTTH networks and offers the greatest potential for future growth.
The next Netly city will be Folsom, CA.