Optics in Cable TV Networks
LightCounting Releases a Research Note
LightCounting has published a Research Note titled “Optics in Cable TV Networks” based on interviews and presentations that took place at the Cable-Tec Expo conference and exhibition held in Denver, Colorado in October 2017, hosted by the Society of Cable TV Engineers (SCTE). This newsletter is an excerpt from the Research Note.
MSOs going “Fiber Deep” to increase bandwidth
Along with the move to DOCSIS 3.1, cable companies are evolving their network architecture, adopting a ‘Fiber Deep’ architecture, which is simply moving to smaller optical nodes, to make more bandwidth is available on the coaxial portion of the network serving the homes connected to a given optical node.
The traditional hybrid-fiber-coax (HFC) networks transmit an RF signal over fiber to a remote optical node, and from there the signal goes over coaxial cable through several RF amplifiers, in cascade, until ultimately reaching the subscriber’s home. One optical node in an HFC network may serve a neighborhood of 500-2500 homes.
A Fiber Deep upgrade increases capacity to the subscribers, and thereby extends the useful life of the Hybrid Fiber Coax network. By extending fiber closer to subscribers homes, the average size of the optical nodes serving area shrinks to 50-150 homes, and eliminates all the cascaded RF amplifiers from the coaxial portion of the network. And of course, moving from 500 homes per node in HFC networks to 50 homes per node in Fiber Deep means that as many as ten-times more nodes – and transceivers – are needed in Fiber Deep networks, which is positive news for suppliers of optical components.
Unfortunately the transition to Fiber Deep also created a congestion problem on the Cable Modem Termination System (CMTS) side of the network, as each new node consumed another port on the CMTS headend unit. To alleviate space and power issues in the headend, a further evolution of the cable architecture was developed and is now being deployed: the Distributed Access Architecture or DAA. A key feature of this development is that the physical layer (either PHY or MAC-PHY) of a CMTS or Converged Cable Access Platform (CCAP) is moved down to the remote node, which are then called ‘remote PHY nodes’ or ‘R-PHY nodes’, often abbreviated as RPD. Moving the PHY layer from headend to node cannot be accomplished using analog optics, so moving to DAA also necessitates moving to digital optics on the headend to remote node link. In practical terms, R-PHY nodes are also Fiber Deep nodes, though they are separate concepts.
In a nutshell, cable networks are transitioning away from using low volumes of analog optics and toward using many more standardized digital optics.
DAA networks will require lots of 10G SFP+ transceivers
R-PHY nodes have two SFP+ ports, one for connectivity to the headend, and the other for redundancy or daisy-chaining to another R-PHY node. 10G SR and LR transceivers are almost universally used in these nodes today. If all of the 116 million US housing units are eventually passed by a cable network, with an average optical node size of 100 households, and if each headend-node link has two SFP+ ports, then roughly 2.2 million transceivers will be deployed. (116 million homes/100 homes/node*2 transceivers/node). This is a rough estimate, because, in practice, the number of ports per node depends on factors such as node redundancy, segmentation configuration, downstream vs. upstream, etc.
All remote node optics must meet either the e-Temp or i-Temp specification for operating temperature range. One conference speaker noted that temperatures inside a typical aluminum remote node housing have been measured as high as 170 degrees F, which is about 77 degrees C. This extended temperature requirement is the same as that required for mobile fronthaul transceivers. One vendor told LightCounting that they have received requests from MSOs for temperature performance beyond the iTemp range, to 90 degrees C or more.
The Research Note also provides information on several related topics, including 10G tunable transceivers being developed for the cable TV market, how 100Gbps transceivers may be used in future cable networks, and how cable MSOs and equipment makers have adapted PON technologies for cable networks.
3D Sensing for Self-Driving Cars Reaches the Peak of Inflated Expectations
LightCounting releases a new report addressing illumination in smartphones and automotive lidarIn 2019, the market for VCSEL (vertical cavity surface-emitting laser) illumination in smartphones will exceed $1.0 billion – now nearly triple the size of the market for communications VCSELs. That’s quite remarkable for a market that didn’t exist three years ago.3D sensing in smartphones felt like an overnight sensation, but the technology foundations were laid down years ago with Microsoft’s Kinect – a motion-sensing peripheral for gamers released in 2010 but discontinued in 2017 after lackluster sales. Lumentum supplied lasers to the Kinect almost a decade before the iPhone opportunity emerged; the company was ready to profit from the iPhone X opportunity when Apple decided to launch 3D sensing for facial recognition in September 2017.
Figure: 3D depth-sensing meets the Gartner Hype Cycle
Source: Gartner with edits by LightCounting
If all technologies follow the Gartner Hype Cycle, shown in the Figure above, then 3D sensing in smartphones is now moving up the slope of enlightenment. Android brands raced to add 3D sensing to their flagship phones in 2018 – the Xiaomi Mi8 Explorer and Oppo Find X phones were first – although these only sold in single digit million quantities. Huawei also brought out new phones with 3D sensing, but the ongoing U.S. export ban on the Chinese company must be hurting the company’s traction outside China. Apple continues to dominate the market as all new iPhones released by Apple since 2017 have included 3D sensing on the front of the phone. Apple is expected to introduce 3D sensing for ‘world-facing’ applications in 2020, which adds another laser chip to every phone.
Last year illumination for lidars were not included in our market forecast since LightCounting considered it unlikely that lidar would penetrate the consumer market to any great extent over the forecast period. All indicators now point to a market for lidar illumination ramping up in 2022 and beyond. Optical components firms are now shipping prototypes and samples of VCSELs, edge emitters and coherent lasers to customers developing next-generation lidar systems – many of them building on their expertise in illumination for optical communications and smartphones.
As was the case with smartphones, the foundations for lidar technology were laid down much earlier – in this case with the DARPA Challenge 2007, where the winning vehicle used a 64-laser lidar system from Velodyne Acoustics (now Velodyne Lidar). Lidar is considered by the majority of the industry to be an essential part of the sensor suite required for autonomous driving, helping the vehicle to navigate through the environment and detect obstacles in its path. The first commercial deployments have begun. In Germany, lidar on the Audi A8 enables the car to drive itself for limited periods under specific conditions. In Phoenix, Arizona, you can hail a ride in a Waymo robotaxi.
Investor enthusiasm for lidar is undeniable with nearly half a billion dollars invested in lidar start-ups in 2019 according to our analysis of publicly available investment data. Notable deals include $60 million for U.S. company Ouster in March, Israel’s Innoviz Technologies Series C round of $132 million in the same month, and $100 million for U.S.-based Luminar Technologies in July. Interestingly, these examples illustrate the variety of lidar approaches: each company is building a different type of lidar based on a different wavelength: 850nm for Ouster, 905nm for Innoviz and 1550nm in the case of Luminar. There’s an open technology battle and they can’t all be winners.
The automotive lidar market seems to be close to the peak of ‘inflated expectations’. It’s easy to understand why. The automotive industry is enormous, with nearly 100 million vehicles (including trucks) produced annually. Players like Baidu, GM Cruise and Waymo are backed by deep corporate pockets, and new entrants like Aurora and Pony.ai are attracting hundreds of millions in investment. Intel’s $15.3 billion purchase of Mobileye in 2017 was also directed at autonomous driving. Sensor company AMS is in a $4.8 billion battle to acquire German semiconductor lighting firm Osram with its eye firmly on lidar.
However, signs indicate that the descent into the trough of disillusionment could have already begun. Waymo has yet to roll out its robotaxi services more widely – and this summer admitted that its vehicles needed more testing in the rain. GM Cruise has delayed launch of commercial services for self-driving cars beyond 2019 and is reluctant to commit to a new timescale, with its CEO Dan Ammann observing that safety is paramount; automotive is not an industry where you can “move fast and break things” he said. A casualty of the slow pace was optical phased array lidar developer Oryx Vision, which closed its doors in August and started to hand money back to investors.
While lidar is being deployed commercially today, prices are not conducive to mass production, and there are open questions around regulation, safety, ethics and consumer acceptance. Do local laws prohibit self-driving cars? Will they really be safer than humans? Who is responsible for a crash? LightCounting remains skeptical about the pace of adoption of autonomous vehicles, but will be watching the market closely and with optimism.
More information on the report is available at: https://www.lightcounting.com/Sensing.cfm.