EC researchers demo multi-gigabit fibre-to-the-home
Running rings around copper broadband
European Commission-funded researchers have declared a high speed broadband research project a success, stating that the “Sardana” project (Scalable Advanced Ring-based Passive Dense Network Architecture) has demonstrated the feasibility and robustness of 10 Gbps fibre-to-the-home networks.
The project, which was supported by €2.6 million from the Commission, also demonstrated that the higher speeds it describes are achievable using off-the-shelf components.
The main architectural change proposed by the Sardana researchers is to fan-out end user connections closer to the home, and using wavelength division multiplexing (WDM) to increase the capacity delivered to the fan-out nodes. A PON environment such as is being used by Australia’s National Broadband Network serves as many as 32 households from a node, which limits the capacity that can be delivered to the end user (although the NBN is designed to start at 100 Mbps, and has been demonstrated at an end-user speed of 1 Gbps).
Serving nodes from a fibre ring also makes the network more robust, according to the Sardana researchers, since connectivity should be able to survive a break in the ring.
More encouragingly, the Sardana pilot demonstrated symmetrical high-capacity connections, rather than the lingering asymmetry that inhibits most current architectures.
“Using WDM on the ring means we can multiply bandwidth by 40 wavelengths so individual users can enjoy 1 Gbps: not just in one direction, but in both directions, both upstream and downstream,” says Professor Josep Prat of the Universitat Politècnica de Catalunya, coordinator of the project.
“This could open the door to entirely new applications that are simply not possible today, such as high definition video conferencing.”
The trial network included lab tests by Tellabs, a field trial in Brittany, and a demonstration at the FTTH Council in Milan. The tests showed that the Sardana architecture could serve as many as 4,000 users with symmetrical 300 Mbps connections up to 20 Km from the main ring, or up to 250 users 100 km from the main ring, with 10 Gbps / 25 Gbps asymmetrical services. ®
Re: That's all nice and everything....
Which is why a company I used to work for partnered with local electricity companies. Since fibre is non-conductive they could run the backhaul at the top of the poles next to the electricity cables (not the high tension stuff, regular telegraph pole voltages) and only have to come down the pole for the last few hundred feet to the customer which at the time (and this was 10 years ago) was done over coax as FTTP was not feasible at the time (we did the work and couldn't figure out how to terminate hundreds of thousands of fibres per town - the patch panel would take several floors of our termination facilities on its own)
In metro areas its a little more challenging. You'd like to use horizontal directional drilling as that stops you from digging up roads, but most cities have out of date or incorrect utility maps so tearing up the street to lay new conduit is the only way to do it. Washington DC tried to get the utility companies to agree to a construction schedule so that a street would only be dug up once but they couldn't make it work - a moratorium on digging was imposed, meetings were held, and then the moratorium was lifted and life went on as before. Parts of the San Francisco Bay area (I think San Jose particularly) did manage to do that when the fibre companies were trenching in tons of fibre and on some streets the manhole covers are in groups and always in the same order as a result.
The real problem that stops FTTP isn't that it costs a lot of money, its that the companies that have the money to do that are typically the same companies that have a ton of copper in the ground or on poles already serving your phone and/or cable TV services. Ripping that out and replacing it with fibre is not something that goes down well with shareholders as you're destroying infrastructure you paid for and is essentially free at this point. Its difficult to make money off the investment as you have to compete with other people that haven't replaced their copper infrastructure and may not have a good a service, but people frequently don't look at the quality, they look only at the bottom dollar/pound/<insert your local currency here>.
Pft, symetrical gigabit connections to the home represent the beginning of the end for company offices, with knock on effects for transport networks, real estate and IT as teleworking becomes the norm for a lot of employees, cities will empty and 'rush hour' will become just another olden days thing you will try to explain to your disinterested kids.
Roll on the future.
No, you don't want passive networks
Even with WDM it means you will still have to run any old standard your customers still happen to have over those lines. Eventually with services being shifted in and out according to demand, you'll end up with a patchwork of used wavelengths. Should you ever have to have some WDM standard you might not have the space as some customers still require some ancient standard for business critical operation.
Laying fiber to the customer is a multi-decade operation. It's the first substantial upgrade of the phone network. We shouldn't botch this by using passive networks, just run a dedicated pair of fibers from every home at least to the curb. Unlike copper fibers are incredibly cheap. Always keep in mind that we will have to use whatever we put in the ground for the next 50-100 years.