Tag Archives: Data rate units

New and Better WiFi

Wi-Fi Signal logo

Wi-Fi Signal logo (Photo credit: Wikipedia)

There are two new standards for WiFi that will be hitting the market in the next few years. The standards are 802.11ac and 802.11ad. The two new standards use different spectrum with 802.11ac at 5 GHz and 802.11ad at 60 GHz. Both new Wifi standards will be able to deliver up to 7 gigabits per second, compared to today’s WiFi that tops out at 600 megabits per second.

Looking at basic spectrum characteristics there are four major differences in the way these two standards will use the spectrum:  bandwidth available, propagation characteristics, antenna size and interference.

The maximum data speed that can be delivered by any radio spectrum is limited by the amount of spectrum used and the signal-to-noise ratio. This limit is defined by the Shannon-Hartley Theorem. The 802.11ac at 5 GHz can use about 0.55 GHz of spectrum. The 802.11ad at 60 GHz can use up to 7 GHz. 802.11ac has channels that are 160 MHz wide while 802.11 will have channels that are 2,160 MHz wide. But the channels in 802.11ac can be bonded which will allow it to deliver almost as much bandwidth as 802.11ad.

802.11ac will use the same 5 GHz spectrum that is used by today’s Wifi and will have similar propagation characteristics. But the 802.11ad spectrum at 60 GHz will not travel through bricks, wood or paint and thus this technology will be most useful as an in-room technology.

For these spectrums to achieve full potential they need to be able to transmit multiple signals, meaning that they need multiple antennas. Antenna size is proportional to the wavelength being transmitted. A 5 GHz antenna has to be about an inch long and spaced at least an inch apart to be effective. But 60 GHz antennae only need to be 1/10 inch long and apart. This is going to make it easier to put 802.11ad into handsets or into any small device.

Finally is the issue of interference. There is already a lot of usage in the 5 GHz band today. In addition to being used for WiFi the spectrum is used for weather Doppler radar. There are also a few other channels in the band that have been allowed for other uses. And so 802.11ac will have to work around the other uses in the spectrum. The 60 GHz spectrum range is mostly bare today, and since this will go such short distances there should be very few cases of interference. However, multiple 801.11d devices in the same room will interfere with each other to some extent.

The 80211.ac standard is pretty much set but won’t be fully certified until 2014. However, there are already devices being shipped that include some of the features of the standard. For example, it’s included in the Samsung Galaxy S4 and MacBooks. But today’s version uses beamforming to send the signal to one device at a time. Beamforming means that the signal is sent to one device from each separate antenna in an array, but at slightly different times.

Still to come is the best feature of 80211.ac, which is to support separate sessions with different devices, different priorities and different power needs. This feature is called multi-user MIMO and it will revolutionize the way that WiFi is used. For example, you will be able to make a WiFi voice call while simultaneously downloading a video from another device. Your WiFi chip will determine the location of each device you will be talking to and will initiate a prioritized session with each. In this example it can give priority to the voice call.

The fully deployed 80211.ac will be the first generation wireless that is getting ready for the Internet of Things. It will be able to communicate with multiple devices in the environment at the same time. It will turn smartphones and tablets into workhorses able to gather data from sensors in the environment.

802.11ad is going to be far more limited due to its inability to pass through barriers. The most likely use for the spectrum will be to create very high-speed wireless data paths between devices, such as connecting a PC or laptop to a wireless network. It should be able to achieve speeds approaching 7 Gbps with only one device and one path in play.

One would expect by 2016 or 2017 for devices using these two technologies will become widespread. Certain in the telecom industry an upgrade to 802.11ac will allow carriers to deliver more bandwidth around a home or office and be able to handle multiple sessions with wireless devices. This new technology is a fork-lift upgrade and is not backwards compatible with earlier WiFi devices. This means it will take some time to break into the environment since all of the local wireless devices will need to be upgraded to the new standard. One would expect first generation 802.11ac routers to still include 802.11n capabilities.

G.Fast

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 just announced a field trial of G.Fast. That trial 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.

Right now Alcatel-Lucent is spending a lot of time on G.Fast because they see a big opportunity to make more money out of the old copper networks. So let’s look at the issues that a large telco like AT&T will face when considering the technology:

  • Because the distances to deploy G.Fast are so short, the carrier is going to 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.
  • Copper drops are generally the worst copper in the network. These wires get banged around by wind and suffer from repetitive water damage and are the weak point in the copper network. The promised savings from G.Fast is to lower the cost of installation at a customer. Some of this savings disappears if too many homes need a new drop to make it work.
  • G.Fast will save the cost of getting into the house. Once connected to an existing telephone NID on the outside of the house the signal can go anywhere in the home that is already wired for telephone. But the distance issue quickly kicks in and I would expect carriers to take this to a wireless right inside the house.
  • Savings are going to depend on how inexpensive the G.Fast electronics are compared to FTTH electronics.
  • Large telcos have relied for years upon customer self-installation of DSL and they will need G.Fast to work the same way.

So the savings to somebody like AT&T come from a) cheaper fiber installation costs because of the ability to overlash, 2) the ability in many cases to use existing drop and inside telephone wires, and 3) the ability to have customers self-install the product to avoid having to go into the home.

There are still a lot of technical issues to consider and overcome. Some issues that come to my mind include things like overcoming existing splices in the copper, and making sure there is no interference with existing DSL.

The expected time line for the deployment of G.Fast is as follows:

  • Standards finalized by spring of 2014.
  • Chip sets developed in 2015.
  • First generation hardware available in 2016 that probably won’t support vectoring.
  • Mature second generation equipment available in 2017.

Since a carrier has to build fiber everywhere for this to work, the technology is really competing against FTTH. By the time this is readily available there may be lower-cost units for FTTH deployment and I think any carrier would prefer an all-fiber network if possible.

Broadband and Schools

Satellite Internet dish attached to a...

English: Satellite Internet dish attached to a building in rural America (Photo credit: Wikipedia)

Earlier this month President Obama announced an initiative to get 1 Gbps or at least 100 Mbps broadband to 99% of schools within five years. The new plan is being referred to as ConnectEd and the citation takes you to a posting on the White House web site that outlines the program.

The program will have several components. The one that will be most familiar to the readers of this blog is that the program will provide improved connectivity through the E-Rate program that is part of the current Universal Service Fund. The E-Rate program for years has been providing subsidies to bring broadband to schools and libraries in the poorest communities. One has to imagine that the FCC is going to expand that program to include money to build fiber in rural communities. It’s not clear yet how it will work, but the administration has said that the NTIA (National Telecommunications and Information Administration) will take a lead in moving the program forward.

The second component of the plan will provide more training for teachers to be proficient in the technology that broadband will bring to the schools. This will be done with funding through Title II and Title VI programs through the Department of Education.

I don’t think there is anybody who can fault the goal of this plan which is to make sure that kids have access to broadband at school. Certainly students at schools that do not have broadband access will fall behind everyone else.

But for rural areas this is not enough. Over the last few years there has been a number of ‘middle-mile’ fiber networks built as part of the BTOP program using money from the 2009 Stimulus program that built rural fiber. The middle-mile projects built fiber through rural areas and also connect to ‘anchor institutions’ in those areas, meaning schools, universities, libraries and government buildings.

But in far too many cases those are the only places that got broadband out of the billions of dollars that were spent to build fiber. This is not a blanket indictment of the BTOP program because in some cases that fiber has been an incentive for carriers to build last mile fiber or wireless networks to serve rural customers. But I am also aware of many examples of BTOP fiber networks that bring fiber through a rural town, connect a school and a City Hall and nobody else.

And in many of those communities the existing broadband is poor or non-existent. It is very typical to have some sort of broadband in the towns in rural counties – generally DSL supplied by the phone company or cable modems supplied by a cable company. But in most cases the broadband in these towns is far slower than what is routinely available in big cities. But one generally only has to go a mile or two outside of these rural towns and the broadband stops. There are hundreds of counties that have this situation.

And in a lot of these areas without landline broadband there is also inadequate wireless broadband. Fiber is needed to provide broadband to cell towers if we want to use them to provide 3G or 4G data. Most rural cell towers were built along highways to serve cars and are not built where people live. And so in many rural areas there is no effective broadband.

And so it leads me to ask if there is not some way to help the communities around the schools while we bring broadband to the schools. 100 Mbps or 1 Gbps to a school is a great thing and I applaud this effort. But are we really helping rural students if once they leave school they don’t have enough broadband to do homework?

The original BTOP program that built fiber through rural communities did not go far enough. We need some way in this country to now build the rest of the fiber network and connect everybody. I would be a lot more excited about this announcement if it said that we were going to bring fiber to 99% of rural homes in five years.

I work with a lot of rural communities trying to get funding to build fiber and it is tough. These projects suffer from having a large infrastructure cost per household due to the sparse population in rural areas. These projects have a hard time getting funded through traditional funding sources like municipal bonds. If the federal government really wants to help rural areas get fiber they should be looking at ways that would help get rural fiber projects funded.

I don’t think it’s necessary for the federal government to step in and hand out the money to build rural fiber. That would probably just give us more BTOP programs and networks. But there are concrete steps the federal government could take that would make it easier to get this done. Rural communities are willing to pay for fiber themselves, but that desire is meaningless if nobody will lend them the money. So the best way to help rural America get broadband is to make it easier for rural communities to do it themselves. That is going to mean something like loan guarantees or lower interest rates for these projects.

The federal government already operates a ‘bank’ to provide rural broadband at the Rural Utility Service (RUS) that is part of the Department of Agriculture. But that money is so hard to obtain by rural governments that it might as well not exist. It would be easy to make the RUS into a functional program – it just takes the will to make it work.

In the last year we have had two big announcements at the federal level about broadband. One was to promote gigabit cities and now we will have broadband to 99% of schools. I am still waiting for the announcement that matters – to bring broadband to people.

Make it Faster

Cable modem Motorola SurfBoard for broadband i...

Cable modem Motorola SurfBoard for broadband internet (Photo credit: Wikipedia)

Whenever I look at my client’s data products I almost have the same advice – make it faster. I am constantly surprised to find companies who deliver small bandwidth data products when their networks are capable of going much faster. I have come to the conclusion that you should give customers as much bandwidth as you technically can deliver, within any technical restraints.

I know that networks are operated largely by engineers and technicians and very often I hear the engineers warn management against increasing speeds. They typically are worried that faster speeds mean that customers will use more bandwidth. They worry that will mean more costs with no additional revenue to pay for the extra bandwidth.

But the experience in the industry is that customers don’t use more data when they get more speeds, at least not right away. Customers do not change their behavior after they get faster data – they just keep doing the same things they were doing before, only faster.

Of course, over time, internet data usage is steadily increasing on every network as customers watch more and more programming on the web. But they are going to increase usage regardless of the speed you deliver to them as long as that speed is fast enough to stream video. Going faster just means they can start watching content sooner without having to worry about streaming glitches.

The engineers do have one valid point that must be taken into consideration, in that many networks have chokepoints. A chokepoint is any place in a network that can restrict the flow of data to customers. Chokepoints can be at neighborhood nodes, within your network backbone, at devices like routers, or on the Internet backbone leaving your company. If your network is getting close to hitting a chokepoint you need to fix the issue because the data usage is going to grow independently of the speeds you give your customers. When I hear worry about chokepoints it tells me that the network needs upgrades, probably sooner rather than later.

Historically telecom companies were very stingy with data speeds. The first generations of DSL didn’t deliver speeds that were much faster than dial-up and even today there are many markets that still offer DSL with downloads speeds of 1 Mbps. Then cable modems came along and they upped speeds a little, with the first generation of cable modems offering speeds up to 3 Mbps. And over time the telcos and the cable companies increased data speeds a little, but not a lot. They engaged in oligopoly competition rather than in product competition. There are many notorious quotes by the presidents of large cable companies saying that their customers don’t need more speed.

But then Verizon built FiOS and changed the equation. Verizon’s lowest speed product when they launched service was 20 Mbps, and it was an honest speed, meaning that it delivered as advertised. Many of the DSL and cable modem speeds at that time were hyped at speeds faster than could be delivered in the network. Cable modems were particular susceptible to slowing down to a crawl at the busiest times of the evening.

Over time Verizon kept increasing their speeds and on the east coast they pushed the cable companies to do the same. Mediacom in New York City was the first cable company to announce a 50 Mbps data product, and today most urban cable companies offer a 100 Mbps product. However, the dirty secret cable companies don’t want to tell you is that they can offer that product by giving prioritization to those customers, which means that everybody else gets degraded a little bit.

And then came Google in Kansas City who set the new bar to 1 Gbps. Service providers all over the country are now finding ways to 1 Gbps service, even if it’s just to a few customers.

I am always surprised when I find a company who operates a fiber network which does not offer fast speeds. I still find fiber networks all the time that have products at 5 Mbps and 10 Mbps. In all of the fiber-to-the-premise technologies, the network is set up to deliver at least 100 Mbps to every customer and the network provider chokes the speeds down to what is sold to customers. It literally takes a flick of a switch for a fiber provider to change the speed to a home or business from 10 Mbps to 100 Mbps.

And so I tell these operators to make it faster. If you own a fiber network you have one major technological advantage over any competition, which is speed. I just can’t understand why a fiber network owner would offer speeds that are in direct competition with the DSL and cable modems in their market when they are capable of leaping far above them.

But even if you are using copper or coax you need to increase speeds to customers whenever you can. Customers want more speed and you will always be keeping the pressure on your competition.

Should You Build a Cable TV Headend?

I still meet new businesses all of the time who are just entering the cable TV business for the first time or who are opening up remote markets from their service core. In the past it was a no brainer to build a new headend for a new market as long as that market had enough potential customers to justify the capital outlay. But I find myself hesitating today when I am asked the question of whether one should build a new headend. I don’t think the answer is an automatic yes any longer and there are a number of reasons for this.

Transport. One huge consideration is bandwidth transport. It always makes more sense to use the signal from an existing headend somewhere as long as you can get the signal there for less ongoing cost than building a new headend. The amount of bandwidth needed to transmit a full channel line-up is huge and can easily require at least 100 Mbps. The bandwidth varies a lot depending upon the specific method that is being used to send the TV signal to customers. For example, the bandwidth needed to send a lineup that has both analog and digital tiers will be larger than a lineup that is all IPTV. And the amount of bandwidth is even greater if you want to transmit video on demand.

The price of transport varies widely by location due to the availability of fiber, but overall there has been a big reduction in transport prices. The long-haul transport business has gotten very competitive and there are a host of companies that sell not only bandwidth, but also dark fiber or fiber lamdas. Also, a number of new middle-mile networks were built with federal stimulus grants and those networks, by definition, have to offer reasonably priced bandwidth. In many cases I am seeing transport as a good alternative to building a new headend, whereas a few years ago building a headend almost always looked like a lower-cost alternative.

Aggregators. You also should consider using a network aggregator. One that many of my clients use is Avail Media. Avail has aggregated a channel line-up that comes from the satellite directly in MPEG4 format, meaning that it can be taken directly from the satellite and used in an IPTV distribution network. The advantage of doing this is in the cost savings for the headend. A lot of the capital cost in a traditional headend is spent for equipment that translates TV signals from one format to another. The cost, size and power requirements for a headend drop significantly if the TV signals don’t have to be translated.

Of course, Avail and others aggregators charge a premium for getting the signal to you in the right format and you need to do the math to make sure that there is a net savings in equipment compared to their ongoing transport charges. But many of my clients have found aggregator arrangements that have saved them money.

Headend Sharing. Before I would build a new headend today I would always look around to see if there is an existing headend in the area that I could share. Generally, almost anybody except for the major cable companies would be interested in sharing a headend. Sharing a headend can help a headend owner offset the cost of running their headend while requiring very little ongoing effort after the initial connection.

There are a number of issues to consider when thinking about sharing a headend, but I have dozens of clients who have figured out ways to share. The biggest issue is the signal format. For example, it would make no sense to share an analog headend with somebody who is operating an IPTV system. The cost of translating channels from analog to digital would be almost as costly as building a new headend. There are also contractual issues with some of the programmers who make you jump through extra legal hoops before they will agree to let you transport signal from an existing headend to a different operator in a different market. But headend sharing makes a lot of sense and today, and sharing would almost always be my preference over building a new headend.

Other Issues.  There are always other considerations to consider. For example, if you share a headend or buy content from an aggregator you are still going to have to somehow insert the local must-carry networks onto your system. So you will need to a ‘mini-headend’ of some sort that lets you add your own content to the content that comes from somebody else.

Even if you share somebody else’s headend you might want to consider operating and inserting your own video-on-demand. This will cut down on the transport needed between the locations. If the market is large enough you also might want to consider inserting your own local advertising rather than inflict ads from some distant market upon your customers.

What’s Up With Verizon?

1980s Dodge Ram Van Verizon

1980s Dodge Ram Van Verizon (Photo credit: Wikipedia)

I have another story to tell about my friend Danny. He runs an accounting firm in northern Virginia and he looks a lot like a ton of other small businesses. He has half a dozen phone lines and he wants a fast Internet connection. He called me the other day and told me that he had been approached in just the course of one week by three different salespeople who represented Verizon.

His first contact still has me shaking my head. A salesman stopped by and offered to sell him an all-in-one T1. Danny already has FiOS and a symmetrical 35 Mbps Internet connection. This salesperson wanted to sell Danny a T1 from Verizon or from half a dozen other CLECs and resellers. And he could do this for only $1,400 per month, which is 3.5 times what Danny is paying for vastly better service.

I was really surprised by this sales call. This is a flashback to the late 90’s when there were salespeople everywhere selling the all-inclusive T1 that had some channels for voice and the rest of the T1 for data. And in those days since we had all just migrated from the dial-up world, this seemed like fast Internet access. But then DSL and cable modems, and now fiber and 4G have all left T1s far behind and I was surprised that there was a company who would spend the money on a salesperson to go door-to-door with last century’s product. That seems like the telecom’s version of a buggy-whip salesman.

But Danny says that in his CPA practice that he has at least 50 clients who still use T1s. He advises them every year to move to something better, but I guess there are a lot of people in the world who stick with what is comfortable and working. Such customers could save a lot of money moving to something else and would get far faster Internet access to boot. But I guess the fact that these kinds of customers are still out in the market explains the T1 salesman. There is so much profit in a T1 at his prices that one sale per month probably keeps him happy and very profitable.

Next Danny got a visit from Verizon Wireless. They wanted him to ditch his FiOS and go completely wireless with 4G. Danny has had his FiOS for four years and has never had a single problem. During that time Verizon has increased his bandwidth without changing the price. He is completely happy with fiber and he knows that fiber is the ultimate pipe if he wants bigger bandwidth in the future.

4G is an interesting product, but nobody thinks that a wireless network is as reliable as the FiOS fiber. Cell towers sometimes go down or get overwhelmed with service requests. And the 4G speeds vary by how many customers are using it at any given time. 4G is nice, but it is not fiber.

Danny says that the 4G salesperson could not answer some basic questions. For instance, they could not tell him the speeds he could expect at his location but only could talk about a possible range of speeds. And they never asked him any questions about his business. There certainly are going to be businesses where 4G might be the right solution, but Danny is not one of them. His accountants work in the office and clients come to see him. His major concern is reliability and he loves that FiOS stays up and running. Before FiOS he had a Comcast cable modem and had to send employees home several days when the Internet was not working. Danny is a happy Verizon customer and is sold on their fiber. Danny was somewhat amazed that the 4G salesperson did not know that he already had FiOS and it seems like the different parts of Verizon don’t talk to each other.

Finally last week Danny got a call from a FiOS rep. He had not gotten a call about his FiOS since he first bought it, but I guess that the Verizon FiOS group knew that Verizon Wireless was out trying to poach their customers and they called to check on him. So within the span of one week Danny was contacted by three different salespeople, two from Verizon and one who was a Verizon reseller.

This surprised me for a number of reasons. First, I honestly would have thought the day of selling T1s was dead and that visit just has me shaking my head. But the idea that two different parts of Verizon would spend for sales resources to compete for the same customer has me flummoxed. I understand that the Verizon fiber and wireless businesses are separate business units. But at the end of the day their profits all roll up to the same bottom line.

It appears to me that Verizon has missed one of the basic principles of selling – putting the customer first. A lot of my clients are CLECs and they learned a long time ago that the way to get loyal customers is to get to know them and find them a solution that fits what they need. This approach is called consultative sales and involves taking the time to get to know the customers’ needs. In the early days of CLECs they all sold on price and they quickly learned that a customer who changed to them for a lower price would also drop them for the next lowest offer. The CLECs who are still around today are for the most part doing it right and selling in a way to earn trust and loyalty from customers.

It honestly surprises me that Verizon has not learned this simple lesson. Danny says that the wireless salesperson never asked him about his business and only spouted that 4G was the latest and greatest product. It further surprises me that Verizon would put a live sales staff on the street to compete against themselves. Sales teams are expensive and it’s hard to fathom why Verizon would send a wireless salesperson to a place that already has Verizon FiOS. You would think at a minimum they would send salespeople only to those places that don’t already use Verizon. But once they heard he had FiOS they still tried to convert him to wireless.

Why would Verizon compete against itself like this? I know that there are different business units at Verizon and that each group will earn bonuses based upon their own performance, but at the end of the day it is more profitable as a corporation to do this the right way. Verizon ought to be sending out one sales team that can sell their whole product line and who will help the customer find the best solution for their business. In the long run it can’t do Verizon any good having salespeople bashing their own product lines. As a corporation do they really want wireless salespeople telling the public not to use their fiber? That is going to lead customers to pick somebody other than Verizon.

I think Danny has it right. When his receptionist hears the word Verizon now she just tells them, “He doesn’t want to talk to you.” And she is right.

How Much Bandwidth Can a Cable TV System Deliver?

Cut showing the composition of a coaxial cable.

Cut showing the composition of a coaxial cable. (Photo credit: Wikipedia)

There are a number of techniques that are available for a traditional cable TV network to upgrade the bandwidth on the network available for customer data. If you are operating or competing against a cable TV system you should recognize that there are a number of upgrades that can when combined can drastically improve data speeds. Each of these upgrades comes at a cost, but you can’t discount the technical capabilities of an HFC network if data delivery becomes the primary goal of the network.

  1. Increase System Bandwidth. An example of this kind of upgrade is when a system is upgraded from 750 MHz to 1,000 MHz (or 1 GHz). This upgrade provides more bandwidth by widening the frequencies that are available on the coax. A system bandwidth can be a major upgrade and can involve replacing all of the power taps in the system, and in some systems even requires replacing the coaxial cable.
  1. Reducing Node Size. A node in an HFC system is a neighborhood of homes and/or businesses that share the same bandwidth. Typically there is fiber built to a node and then coax cable from the node to each customer. Historically, before cable modems, nodes were large, often at 1,000 homes or more. But many cable companies have deployed more fiber and reduced node sizes and some cable companies now have nodes in the 200 customer range. Making smaller nodes creates smaller pools of shared bandwidth, meaning there is more bandwidth available to customers at peak times.
  1. MPEG4 Compression. A lot of cable systems still use a compression technique known as MPEG2. This technology is used to compress the digital channels on a network today so that up to ten digital channels will fit into one 6 MHz analog slot. But with MPEG4 as many as 20 digital channels can fit into the same 6 MHz slot. The biggest issue with this conversion is that older set-top boxes won’t recognize MPEG4.
  1. Deploy DOCSIS 3.0. DOCSIS 3.0 is a bandwidth management technology that allows a cable modem to use a larger window of RF frequency for data. The way this works is that a cable system can ‘bond’ multiple channel slots together to that the cable modems can use more than one 6 MHz channel slow for data.
  1. Migrate Analog Channels to Digital. A cable provider can gain some bandwidth space by migrating analog channels to an existing digital line-up. There are often contractual requirements with programmers that make this difficult to achieve. However, as mentioned above, as many as 20 digital channels can fit in the same sized slot as an analog channel. There are always customer issues to also consider since this kind of conversion will shrink the analog offering and expand the digital tiers.
  1. Full Digital Conversion. In a full digital conversion all channels are converted to digital. Once completed, every customer needs a set-top box or other device in order to decode and view channels. There is now a device called a Digital Television Adapter (DTA) that is less costly than a set-top box that can support a customer remote. It is possible to send the ‘basic’ channels through the network un-encoded so that customers with a digital QAM tuner in their TV will be able to see these channels without a DTA.
  1. Deploy Data QOS. This technique does not increase system bandwidth, but rather allows the cable provider to sell faster data to some customers by allowing those customers to use a frequency allocation that is only used by these faster data customers. For example, Comcast advertises 100 Mbps service in most large cities, and they would deliver that kind of speed by giving the 100 Mbps customer priority over other customers in the node by having those customers send their data over a lesser-used frequency on the COAX. Of course, as the priority customer gets more bandwidth, everybody else in the node gets degraded service, and if too many premium services are sold then even the priority customer can’t get the promised bandwidth. But this technique does allow the cable company to selectively compete against fiber for selected customers willing to pay for the extra speed.
  1. Convert to IPTV. This conversion would allow a cable system to use more of the RF frequency on the network for bandwidth. On an IPTV system the programming, voice and cable modem service are all sent over shared bandwidth. An IPTV conversion does not automatically gain a lot of extra bandwidth and any savings come from the fact that the company does not have to broadcast all channels to all nodes all of the time, but rather can just those channels that somebody in the node is watching. There is a benefit, but it is not as large as the extra bandwidth gained by other strategies.
  1. Higher Spectral Efficiency. This technique involves converting to DOCSIS 3.1 and also changing the system modulation techniques. The traditional modulation technique is called QAM (Quadature Amplitude Modulation) and uses a 6 MHz frequency allocation.  The new technique is ODFM (Orthogonal Frequency Division Multiplexing) which uses a higher QAM modulation.  Where Current DOCSIS capabilities achieve approximately 6.3 bits per Hertz, DOCSIS 3.1 can achieve 10 bits per Hertz. New modulation techniques can create much larger bandwidth slots and can at the same time increase the bits to Hz efficiency of the frequency being used. In effect, this technology turns the cable system into a DSL system, with the difference being that there is more frequency available on a coaxial cable than is available on a telephone copper cable, but that a CATV node is then shared by multiple subscribers.

As can be seen, a cable company has a lot of options to increase bandwidth. So, how much bandwidth can be delivered? There are a lot of cable networks that have been upgraded through step 7 above. These systems can support some selected customers up to 100 Mbps download. But these systems probably only support 30 Mbps for all subscribers if the nodes are small enough. A system that is upgraded through step 8 can probably deliver 50 – 60 Mbps to most customers with selected customers being able to get much faster speeds. But a full upgrade to through step nine would allow a cable system to match the overall bandwidth delivered by a fiber PON system, although it is then shared with a lot more customers.

These upgrades are expensive. But if you are competing against a cable company, don’t assume that they are incapable of delivering very decent internet speeds if they are willing to make enough investment in their network.

If you have questions or want to discuss this further call Derrel Duplechin at CCG at (337) 654-7490.