Resultados y análisis en relación a otros maestros 31

!

What is the likely migration for each of the existing technologies in the future? Also, are there any new technologies on the horizon that might bring broadband affordably to consumers?

!

Future of DSL – G.Fast

!

DSL speeds are expected to increase over time with new innovations. In the labs there have been DSL technologies tested with speeds up to 500 Mbps. However, the high bandwidth DSL

variants tend to have characteristics that drastically reduces the bandwidth with distance. Distances for very-high-speed DSL is 150 feet or less and is expected to be useful in conjunction with Fiber-To-The-Curb (FTTC) deployments. A FTTC system would still require fiber traversing every street, but use copper drops and DSL instead of fiber drops. FTTH costs more than a FTTC system today, but can deliver tremendously more bandwidth.

!

You are going to start hearing about a new technology that may infuse some life back into existing copper networks. The technology is being referred to as G.Fast. This technology promises to be able to deliver very fast speeds up to a gigabit over copper for very short distances. Some are referring to G.Fast as a last mile technology, but it is really a drop

technology. The distances supported by the technology are so short that this is going to require fiber to the curb, or as some are now calling it, fiber to the distribution point.

!

Alcatel-Lucent and Telekom Austria recently did a field trial of G.Fast that achieved a maximum speed of 1.1 Gbps over 70 meters and 800 Mbps over 100 meters for brand new copper. On older copper the speed dropped to 500 Mbps for 100 meters.

!

Current copper technologies use only a small portion of the theoretical bandwidth available on a copper wire. For example, most VDSL2 systems deployed today use up to 17 MHz of spectrum on the copper. G.Fast can provide more speeds by using more of the available spectrum and will be able to use somewhere between 70-140 MHz on copper. Plus G.Fast will be more efficient. Today DSL functions by dividing the data path into sub channels which each contain about 15 bits of data. Engineers are looking at coding and modulation techniques that will increase the bits per sub channel for G.Fast and thus increase speeds more.

!

G.Fast also will benefit by an existing technique called vectoring. This technology is used today with VDSL2 and eliminates crosstalk interference between copper pairs. It does this by

monitoring the noise on copper and then creating an anti-noise signal which cancels the noise in the same was as is done by noise-canceling headphones.

!

Because the distances to deploy G.Fast are so short, a telco will have to build fiber past every customer, just like in a FTTH network. A large carrier like AT&T has some advantages over a fiber overbuilder in that they can overlash fiber onto existing copper on pole lines. This is

cheaper and faster than putting up fiber for a new provider who has to deal with pole make-ready costs.

!

Future of Cable Modems - Future DOCSIS

!

Anybody who uses a cable modem at home has probably heard the acronym DOCSIS. This is asset of standards that define how data is transmitted over coaxial cable networks. DOCSIS

stands for Data Over Cable Service Interface Specification. It was developed by CableLabs,

and development purposes. CableLabs is to the cable TV world what Bell Labs always was for the telephony world.

!

DOCSIS 1.0 was first issued in 1997 as a standard and created the basis for cable modems. It established a data network that started with a CMTS (cable modem terminal system) that talked to cable modems in each home. DOCSIS 1.0 was limited to a single data channel which means that data speeds were limited to a usable 38 Mbps download and 9 Mbps upload for everybody together on a cable node. Because the data was shared with anywhere up to 200 homes, speeds on DOCSIS 1.0 were generally limited to a maximum of about 7 Mbps, although these speeds could be much slower at peak times.

!

The standard was updated in 1999 to DOCSIS 1.1 which allowed for QoS (Quality of Service) which enabled cable systems to carry voice calls, with priority, on the cable modem data path. There are still a significant number of field deployments using DOCSIS 1.0 and 1.1, particularly in smaller and rural cable systems.

!

DOCSIS 2.0 came out in 2001 and the major improvement was to increase upload speeds. Version 2.0 also improved the ability to transmit VoIP. The standard still kept the single channel downstream. As cable companies lowered the node sizes there were DOCSIS 2.0 systems that supported speeds of up to 12 Mbps download.

The cable system in Austin is probably at DOCIS 2.0, although it may be at one of the versions of DOCSIS 1.0.

The biggest improvement with DOCSIS came with version 3.0 which was released in August 2006. This standard allows for bonding cable channels together to make larger data paths to each node. Cable companies that have deployed DOCSIS 3.0 are offering much faster speeds than in the past. Comcast in the US offers 107 Mbps download in urban markets using the newer modems. In Canada, Shaw Cable and Videotron have used DOCSIS 3.0 to offer products over 200 Mbps download. Virgin Media in Britain announced a speed of 1.5 Gbps download and 150 Mbps upload.

!

Why don’t US cable companies offer speeds that fast? There is a trade-off in any cable system between the number of channels that are used for programming and those used for data. While cable companies have undergone digital conversion to free up channels, they have used most of that new space to add high definition channels to their network rather than dedicate the extra space to data. In the future cable companies are going to be able to free up more space if needed by converting their cable channels to IPTV. Today they multicast every channel in the system to every home, but with IPTV they would send only the channels people want to watch.

!

So urban cable companies can probably deliver a gigabit to each customer node, and if they make their nodes faster there is no reason that they can’t have everyday products of hundreds of Mbps. This is going to require a significant investment and will also require a full conversion to

IPTV. One would think this kind of conversion and cost is only going to be incurred in the metropolitan areas.

!

Gigabit Wireless

!

There are wireless technologies on the drawing board that may be able to deliver as much as one Gigabit of data (1,000 Mbps) over very short distances. For example, this spectrum could deliver bandwidth from a pole in front of a house to the computer and TV.

!

This type of bandwidth will only make sense when coupled with a fiber system. If the transmitters and receivers of this technology were made at a low enough cost, such a wireless technology could replace the drop to the house and act just like having a fiber to the house. Such a system would enable a customer to serve multiple TVs and computers and move them around at will without reliance on wires. However, only a fiber system can deliver enough bandwidth to the pole to make such a system work. This technology will depend on the availability of poles near houses, which will be a problem in the new neighborhoods with underground utilities.

!

The Future of Broadband in Austin

!

When talking about the future of these technologies it is important to remember that Austin today does not have the best technology that is available. It’s clear in looking at the data speeds in the community that both the cable modems and the DSL in the community are older technologies. And many of the rural areas of the Austin Public School District still have no broadband other than satellite. And so it is important to note that just because new technologies are developed that it is no guarantee that Austin will ever see them.

!

Austin has already fallen on the wrong side of what I call the digital divide. The large companies are making big investments in the metropolitan areas. It soon will not be hard for customers in most of the Twin Cities to buy 100 Mbps download cable modems if they are willing to pay the premium price. But even the slower cable model products in the Twin Cities are already moving towards 20 – 30 Mbps.

!

And CenturyLink has stepped up DSL speeds in the Twin Cities and has offerings today using their bonded copper pairs of up to 40 Mbps download. And if they roll out G.Fast there in the future the speeds could approach those of a fiber network. This would require them to build fiber everywhere and I think that is on the distant horizon, but it is possible in the cities, or at least in some neighborhoods.

!

And even the cellular carriers have stepped up their game in the Twin Cities to faster cellular data speeds.

!

But these new technologies have not been brought to Austin and are unlikely to be brought there. The incumbent cable and telco in Austin installed the first generation data equipment and have not upgraded it since. But meanwhile there have been several upgrades in the city.

The incumbents are not willing to make the needed upgrade investments in small markets like Austin. They have largely ignored the market for years and the wires are in bad shape compared to the metropolitan areas. And so Austin has fallen behind the metropolitan areas and will never catch up. And the gulf between your technology and the urban technology is only going to grow.

!

There was a time when the digital divide meant the difference between places that had dial-up and places that had something faster. But the digital divide has grown and now most of rural America is several generations of technology behind the cities and there is no real expectation that this gap will ever close.

!

There are real life repercussions of this gap. This means people can’t use broadband in their homes the same way that people in the Twin Cities can. But much more importantly, businesses can’t get the same bandwidth that their competitors in major metros have. In the long run this is going to squelch innovation in the rural areas. Areas on the wrong side of the digital divide are going to have a really hard time in creating jobs or attracting businesses or providing the educational and health services that will let their children stay in the area. And so places on the wrong side of the digital divide, like Austin, will fall further and further down the economic scale and become less relevant to the economy.

!

!

!

Addendum II

!

Below are two maps that show the possible placement of wireless transmitter sites. The first map shows a very basic network that only adds two transmitter sites. The second one shows a fuller network that adds five transmitter sites. These networks are discussed starting on page 42 of the report.