Expanding DOCSIS (Best of 2020)

In 2014, we published the article, “Infinite HD Channels, Forever,” illustrating Adara’s use of switched IP video (SIPV), which is best described as a kind of switched digital video (SDV) on steroids that is able to address unlimited HD and 4K into the foreseeable future. While that’s still the good-value proposition, operators are currently trying to expand their DOCSIS fast enough to keep pace with growing demands on Internet bandwidth. But, what options are currently available to the operator, and what limitations are associated with those options?


Consumer demand for OTT services, 4K video, IoT connectivity, and Internet services continues to drive demand for bandwidth and speed. Commonly, an operator will attempt to satisfy customers by expanding its system’s DOCSIS capacity. At the same time, operators find their RF spectrum getting pinched on the other side by programmers who package high-demand networks with less profitable ones to maximize the return on their own programming assets.

That trend – we call it bandwidth sprawl – is being adopted by more programmers and will likely continue into the future. As it stands, the dynamic is not sustainable. While operators continue to dedicate 75 - 85 percent of their existing bandwidth to video services, those video services can contribute less than 30 percent of their gross margin.

So, what options do operators have available to address the problem?

With its energy efficiencies, 4096 QAM, and potent bandwidth, the first, and obvious, option is to upgrade to the DOCSIS 3.1 standard; it’s the strategy preferred by most operators struggling to find bandwidth.

But, migrating to DOCSIS 3.1 is a spendy proposition that even Comcast, the country’s largest MSO, is just beginning to roll out. With the cost of chip sets, compatible cable modems, and associated deployments being what they are, it takes years for operators to see any sizable return. And with related cable modem termination system (CMTS) upgrades and the like, the time and resource costs will continue to mount. So, DOCSIS 3.1 looks to be promising, but it always seems to be a long way off.

Another option operators are considering is to overbuild existing plant with Fiber to the Home (FTTH), which is both expensive, and takes a long time to deploy. Our bet is that after close investigation, less than 1 percent of systems considering an FTTH overbuilding strategy will go through with it. Most systems have already gone through a very long and costly digital transfer adapter (DTA) roll-out, reclaiming analog spectrum and converting it to digital. While that whole exercise served a purpose back when systems went through it, it only worked for a short period of time, after which their bandwidth filled up again. In most cases, systems added a bunch of HDs just to keep up with satellite competition, and ate up the bandwidth they had added. Now, there’s little left to cope with the demand for 4K and even more HDs.


Still another option is converting MPEG-2 to MPEG4. In other words, if some HDs can be converted to MPEG-4, they can reclaim some bandwidth so that 75- or 85 percent utilization drops to 65 percent, opening up bandwidth for DOCSIS expansion. Recently, a mega-MSO told customers in one of its Midwest mega-systems that those customer will need to upgrade to newer settop boxes that support MPEG-4. Easier said than done. The changeout requires a massive forklift swap-out of set-top boxes, because a big chunk of legacy equipment in use are not MPEG-4 compatible.

Were this mega-MSO to deploy switched IP video instead, this Midwest mega-system would save not only tens of millions of dollars, but would experience significant customer goodwill instead of sowing disruption and aggravation among its customers.

The fourth and most practical option is deploying switched IP video. Compared to other options, SIPV answers these needs in a very elegant and low-cost way. It provides all of the benefits of switched digital video but eliminates the significant challenges associated with SDV. SIPV vs. SDV Switched IP video differs from switched digital video in three important ways. First, SIPV can be deployed at a fraction of the cost of SDV. Second, SIPV is created by back-office utilities that allow the entire unlimited HD/4K line-up to be switched, instead of the long-tailed switching performed by SDV. Lastly, SDV is extremely technologically and operationally complicated while SIPV is not. Without SDV’s complications, SIPV can scale from the largest operators with multiple millions of customers down to those small systems with a couple of thousands of customers.


It’s Adara’s and this writer’s belief that switched IP video is probably the best credible option for making the most of a system’s bandwidth in light of growing Digital TV demand. SIPV can solve bandwidth mitigation problems, while reducing of the challenges and unreasonably high costs that operators face by pursuing any of the other options we just discussed.

Bonus: switched IP video is not only an ’either/or’. We are not saying that operators should employ SIPV and not to migrate to DOCSIS 3.1. We are saying there should be nothing stopping an operator from deploying SIPV now, so that it can achieve Gbps DOCSIS improvements, now, while plants are prepared, and DOCSIS 3.1 is deployed over the next few years. |||||


Rex Porter is Transmit's Technical Editor.