Communications Technology

Trends In The TV Business

Or

Why Satellite Still Matters In The

Age Of Fiber And IP

September 2017

Chris Campbell

404-849-5232

c.campbell@pobox.com

PRESENTATION OVERVIEW

• Basics of TV backhaul and distribution

• Basics of satellite technology

• Tangent: lightning protection

• Satellite economics and logistics

• Fiber backhaul

• Encoding and signaling

• TV distribution shifts

• News gathering shifts

• Video signals in the plant

TV BACKHAUL AND DISTRIBUTION

• TV production is “glass to glass”: starts at glass at front of camera and ends at glass of home display

• Facilities include the studio/venue, production house, transmission, distribution, cable headends, last mile

• Historically, programmers uplink “linear TV” to satellites, bent pipe to cable/MSOs; cable-only model invented in 1970s by Ted Turner

TV BACKHAUL AND DISTRIBUTION

• “Backhaul” hop might be satellite, but is often fiber since it is point to point anyway

• “Distribution” hop to home might be satellite, but is more commonly cable (hybrid fiber / coax or HFC)

• “Transmission” (in the middle) is the one hop that historically must be satellite, because it scales nationwide.

TV BACKHAUL AND DISTRIBUTION

Video compression bitrates squeeze down as you go;

HD video examples:

• Camera: 1500 Mbps, uncompressed HD-SDI on coax

• Backhaul: 100-300 Mbps, JPEG2000 in transport stream

• Distribution: 5-10 Mbps MPEG4 (was 15 Mbps MPEG2)

• Cable/telco/wireless: 1 Mbps ... or worse!(or better, with passthrough)

SATELLITE TECHNOLOGY BASICS

Rockets and space are sexy, but how do satellites work?

SATELLITE TECHNOLOGY BASICS

Satellites are “bent pipes”:

• bandwidth up is simply mirrored back down in a "transponder“, but at a different frequency

• space segment is decidedly LOW tech (an analog “pipe”) but high reliability

• endpoints on ground are high tech (and serviceable, upgradeable)

SATELLITE TECHNOLOGY BASICS

Ku band:

- 10-14 GHz, 2-3 cm wavelength

- smaller uplink antennas (size of SUV), 4.5m to 7m

- somewhat susceptible to rain fade -> add power margin

- heavily used by news trucks

Ka band:

- 26-40 GHz, 0.8-1.2 cm wavelength

- smallest antennas

- extremely susceptible to rain fade -> big power margins

- some use by TV industry for DTH delivery

- most commonly used for internet (spot beams)

C band:

- 4-6 GHz, 5-8 cm wavelength

- big antennas (size of garage), 7m to 15m

- lower frequency drills through rain

- heavily used by TV industry for distribution

SATELLITE TECHNOLOGY BASICS

Broadcast TV distribution:

• no back channel!

• everything is done via one-way communications

• FEC = Forward Error Correction(since retransmit requests are not possible)

• signals are broadcast across continent (or ocean)

• geostationary satellites at 22,000 miles above earth

• fixed antennas at both ends of link (no tracking)

SATELLITE TECHNOLOGY BASICS

Encryption:

• signal is visible to everyone but encrypted

• decryption by combination of hardware (IRDs) and software (keys transmitted OTA)

• encryption is proprietary; keys kept in vendor vaults

• authorization jargon: tiers, blackouts, force tune

• cable headends have IRD pools for sparing (e.g. “NAP”)

• IRD serial number force display for anti-piracy

SATELLITE TECHNOLOGY BASICS

Evolution of digital modulation:

• BPSK

• QPSK/DVB-S

• 8PSK/DVB-S2

• xQAM, rare on satellite,common on cable systems

Efficiency:

• - 2-3 bps/Hz is typical

• - 15-50% eaten up by FEC

Higher order modulation requires:

• low phase noise

• high power

SATELLITE: LIGHTNING PROTECTION

Attract strikes and dissipate energy:

• pointed rods

• conductive grid buried in ground for low impedance

Suppress strikes in the first place:

• fuzzballs!

• Streamer Retarding Air Terminal (SRAT)

• dissipation array tower

Lots of surge protection in buildings where wires come in and out, e.g. optoisolators

SATELLITE: ECONOMICS AND

LOGISTICS

May 2010 failure of Galaxy 10 satellite and subsequent gymnastics:

https://www.youtube.com/watch?v=ZaqUpB4otD8 (AGI, 25 secs)

https://www.youtube.com/watch?v=wVp8UNnG3YE (FridgeFTA, 45 secs)

• a GEO satellite costs on the order of $500M, designed to last 15 years

• use: $2000-$4000 per month per MHz

• $1.5M per year per 36 MHz transponder

• as it nears end of life, transponders will die (and eventually run out of spares)

• stationkeeping: satellite normally “in the box”

• stationkeeping gets loose due to fuel running out, eventually going "inclined", which then requires ground antennas to track; discount rates to customers who can live with that

• in-orbit spare satellites cover the occasional catastrophic failure (May 1998, May 2010, Aug 2017!)

SATELLITE: ECONOMICS AND

LOGISTICS

• Satellite point-to-point speed of execution (for news) can't be beat; keep the space segment ready, set up circuit in 15 minutes, faster if equipment is automated

• If satellite circuit goes down, you only have two endpoints and two people involved

• Fiber circuit takes days/weeks to get set up, but then is wildly cheaper to operate

• If fiber circuit goes down, you have multiple parties involved and it takes 1-24 hours to restore, even just a workaround; "backhoe fade"; for important circuits you buy two and switch between them

FIBER BACKHAUL

Dark fiber vs Transport service

Dark fiber:

• customer-leased fiber, owned by provider

• literally a continuous glass tunnel from end to end

• customer provides terminating hardware

• allows for rapid upgrade or repurposing of lines

• e.g. entire 500 Mhz of L-band spectrum (analog!)

Transport service:

• backhaul provider co-locates their terminating equipment at user’s facility

• remotely managed by provider

• handoff at patch panel, typically ASI (coax) or IP (Ethernet)

• digital signals only

VIDEO ENCODING AND SIGNALLING

• the olde analog days: NTSC (analog compression), BMAC and VC2 (encryption)

• evolution of digital compression: MPEG2 -> MPEG4 -> MPEG4 HEVC(also JPEG2000 for backhaul; “mezzanine” or “light” compression)

• SD vs HD vs 4K

VIDEO ENCODING AND SIGNALLING

The devilish details of TV

distribution:

• FCC requirements that old

distrib has dealt with for

decades

• closed captioning, multiple

audios (languages)

• descriptive audio

• commercial triggers

Last mile providers (OTT) want all

of these just like the big old cable

co’s.

TV DISTRIBUTION SHIFTS

• ~10 years ago: fiber links direct from programmers to major MSOs, with satellite as backup (satellite still used by thousands of tiny cable co’s)

• ~5 years ago: over the top (OTT) feeds; TV via internet to non-STB platforms (incl. mobile, tablet, Roku, Apple TV, Xbox, etc)

• Hulu, TV Everywhere, cable subscription integration

• No multicast, but CDNs

NEWS GATHERING SHIFTS

• ENG = “electronic”; microwave trucks, metro area

• SNG = satellite trucks, cross country or even just two blocks!

• DNG = “digital”; Internet: equip field producer with camera, laptop and editing SW

• each have their pros and cons, but DNG price is unbeatable if you have ISP

• bonded cellular, e.g. LiveU

• quality doesn't matter for breaking news -- grainy cell phone video is just fine

• SPEED is what matters, channel changers will stop at first station that shows story

NEWS GATHERING SHIFTS

Switched video (fiber) services for occasional use (OU):

LiveTime, TheSwitch, VideoLink, Level3/Vyvx ...

VIDEO SIGNALS IN THE PLANT

Convergence of broadcast video world with IP world

SDI started in 1990 MUCH faster than Ethernet (270 Mbps)

Ethernet speed growth curve steeper than video/SDI, overtakes video in ~2012

SDI can’t multiplex videos on a single line (huge demand growth)

Leverage commodity IP hardware and the IP tech curve

Leverage a generation of IP-literate engineers

SDI speed history:

1990: 0.270 Gbps

2000: 1.5 Gbps

2007: 3.0 Gbps

2016: 6.0 Gbps

VIDEO SIGNALS IN THE PLANT

Migration from SDI video switching to IP-based switching results in massive cost savings:

FROM

• niche broadcast hardware

• I x O crosspoint switchers (256x256, 1024x1024)

• $1M SDI router + 1694A coax

TO

• commodity IP hardware

• SDI encapsulation and IP routing

• IGMP + multicast

• $1K Cisco switches + Ethernet

Considerations

• SDI over IP latency: milliseconds instead of microseconds

• dual path uses IP routing and SMPTE 2022-7 Seamless Protection Switching

• FEC (Forward Error Correction) via SMPTE 2022-1

VIDEO SIGNALS IN THE PLANT

In-house monitoring already transitioned:

• IPTV already good enough for 90% of plant(non-technical monitoring including executives)

• No multicast on internet, but now common inside TV plant

• Shut down inhouse coax plant and replace with IP multicast (to desktops and STBs)

Troubleshooting does get much harder:

• Out with SDI, coax, eye patterns, patch panels

• In with Ethernet, Cat5, 10GbE fiber, wireshark

• Move from plumbing model to cloud model

TAKE AWAYS

Satellite vs Fiber delivery:

• Satellite one-to-many model scales better than fiber

• Fiber setup and repair takes forever

• Installed fiber gets better and better

IP in plant

• Expensive niche hardware replaced by commodity IP hardware

• Huge growth in video channels / services requires infrastructure that can multiplex signals

Chris Campbell

404-849-5232

c.campbell@pobox.com