Re: 60ms cross continent
Theoretically, Starlink should be faster cross country than terrestrial fiber. Joe McGuckin ViaNet Communications joe@via.net 650-207-0372 cell 650-213-1302 office 650-969-2124 fax
"In Theroy" -- ROFL Don't get me wrong it would be awesome if that turns out to be the case. On Mon, Jul 6, 2020 at 10:05 PM joe mcguckin <joe@via.net> wrote:
Theoretically, Starlink should be faster cross country than terrestrial fiber.
Joe McGuckin ViaNet Communications
joe@via.net 650-207-0372 cell 650-213-1302 office 650-969-2124 fax
Hi, Startlink 1.0, probably will not have lower latency vs Fiber (either cross country or across oceans) Once the laser based inter-sat links are running (Starlink 2.0?), it should be lower latency vs Fiber. With ground stations only: https://youtu.be/m05abdGSOxY With laser links: https://youtu.be/QEIUdMiColU -Harry On 7/6/20 8:00 PM, james jones wrote:
"In Theroy" -- ROFL
Don't get me wrong it would be awesome if that turns out to be the case.
On Mon, Jul 6, 2020 at 10:05 PM joe mcguckin <joe@via.net <mailto:joe@via.net>> wrote:
Theoretically, Starlink should be faster cross country than terrestrial fiber.
Joe McGuckin ViaNet Communications
joe@via.net <mailto:joe@via.net> 650-207-0372 cell 650-213-1302 office 650-969-2124 fax
On Tue, 7 Jul 2020 at 06:35, Harry McGregor <hmcgregor@biggeeks.org> wrote:
Once the laser based inter-sat links are running (Starlink 2.0?), it should be lower latency vs Fiber.
I understood it's not clear if this will ever happen. In local constellation it might, but supposedly technology does not currently actually exist to do it between constellations. I don't understand the topic at all, but I got impression that the precision of timing and accuracy of aiming needed is actually a very hard problem. But agreed, should sat2sat communication become possible, there are many legs where starlink latency will improve upon terrestrial. -- ++ytti
Any idea what network protocol(s) used with Starlink? On Tue, Jul 7, 2020, 5:08 AM Saku Ytti <saku@ytti.fi> wrote:
On Tue, 7 Jul 2020 at 06:35, Harry McGregor <hmcgregor@biggeeks.org> wrote:
Once the laser based inter-sat links are running (Starlink 2.0?), it should be lower latency vs Fiber.
I understood it's not clear if this will ever happen. In local constellation it might, but supposedly technology does not currently actually exist to do it between constellations. I don't understand the topic at all, but I got impression that the precision of timing and accuracy of aiming needed is actually a very hard problem.
But agreed, should sat2sat communication become possible, there are many legs where starlink latency will improve upon terrestrial.
-- ++ytti
On 2020-07-07 05:04, joe mcguckin wrote:
Theoretically, Starlink should be faster cross country than terrestrial fiber.
Joe McGuckin ViaNet Communications
joe@via.net 650-207-0372 cell 650-213-1302 office 650-969-2124 fax
When there is no clouds.
This is why adaptive coding and modulation systems exist. Also dynamic channel size changes and advanced computationally intensive FECs. You don't think people working on microwave band projects above 10GHz with dollar figures in the hundreds of millions are unaware of basic rain fade and link budget methodology, do you? On Mon, Jul 6, 2020, 8:44 PM Denys Fedoryshchenko <nuclearcat@nuclearcat.com> wrote:
On 2020-07-07 05:04, joe mcguckin wrote:
Theoretically, Starlink should be faster cross country than terrestrial fiber.
Joe McGuckin ViaNet Communications
joe@via.net 650-207-0372 cell 650-213-1302 office 650-969-2124 fax
When there is no clouds.
On 2020-07-07 06:48, Eric Kuhnke wrote:
This is why adaptive coding and modulation systems exist. Also dynamic channel size changes and advanced computationally intensive FECs.
You don't think people working on microwave band projects above 10GHz with dollar figures in the hundreds of millions are unaware of basic rain fade and link budget methodology, do you?
On Mon, Jul 6, 2020, 8:44 PM Denys Fedoryshchenko <nuclearcat@nuclearcat.com> wrote:
On 2020-07-07 05:04, joe mcguckin wrote:
Theoretically, Starlink should be faster cross country than terrestrial fiber.
Joe McGuckin ViaNet Communications
joe@via.net 650-207-0372 cell 650-213-1302 office 650-969-2124 fax
When there is no clouds.
In my experience, all that ACM has achieved is that when link becomes "slow" and if it rains outside, it means that it will be down completely after few seconds. Previously with CCM or DVB-S without 2, it simply disappear without warning. And yes, I have and cheap and expensive Microwaves >10Ghz too. ACM/VCM really helps if you want to live on the edge, milking each db, (edge of link budget, e.g. small antenna size, interference), and this is actually very important to increase profitability, especially in case of multipoint VSAT, but it is near useless against rain fade.
"no clouds" is overstating the effect somewhat. I've operated a number of mission critical Ku band based systems that met four nines of overall link uptime. The operational effect of a cloud that isn't an active downpour of rain is negligible. Continual overcast of clouds is not much of a problem at all, it's active rain rate in mm/hour and its statistical likelihood, climate parameters of the location. Yes, during rain fade events, current generation VSAT modems will drop all the way down to BPSK 1/2 code rate to maintain a link, with corresponding effect on real world throughput in kbps each direction, but entirely dropping a link is rare. On Mon, Jul 6, 2020 at 9:40 PM Denys Fedoryshchenko < nuclearcat@nuclearcat.com> wrote:
On 2020-07-07 06:48, Eric Kuhnke wrote:
This is why adaptive coding and modulation systems exist. Also dynamic channel size changes and advanced computationally intensive FECs.
You don't think people working on microwave band projects above 10GHz with dollar figures in the hundreds of millions are unaware of basic rain fade and link budget methodology, do you?
On Mon, Jul 6, 2020, 8:44 PM Denys Fedoryshchenko <nuclearcat@nuclearcat.com> wrote:
On 2020-07-07 05:04, joe mcguckin wrote:
Theoretically, Starlink should be faster cross country than terrestrial fiber.
Joe McGuckin ViaNet Communications
joe@via.net 650-207-0372 cell 650-213-1302 office 650-969-2124 fax
When there is no clouds.
In my experience, all that ACM has achieved is that when link becomes "slow" and if it rains outside, it means that it will be down completely after few seconds. Previously with CCM or DVB-S without 2, it simply disappear without warning. And yes, I have and cheap and expensive Microwaves >10Ghz too. ACM/VCM really helps if you want to live on the edge, milking each db, (edge of link budget, e.g. small antenna size, interference), and this is actually very important to increase profitability, especially in case of multipoint VSAT, but it is near useless against rain fade.
On 2020-07-07 08:32, Eric Kuhnke wrote:
"no clouds" is overstating the effect somewhat. I've operated a number of mission critical Ku band based systems that met four nines of overall link uptime. The operational effect of a cloud that isn't an active downpour of rain is negligible. Continual overcast of clouds is not much of a problem at all, it's active rain rate in mm/hour and its statistical likelihood, climate parameters of the location.
Yes, during rain fade events, current generation VSAT modems will drop all the way down to BPSK 1/2 code rate to maintain a link, with corresponding effect on real world throughput in kbps each direction, but entirely dropping a link is rare.
BPSK 1/2 is quite extreme. In my case it was 32APSK 8/9 at 36Mhz transponder (yes it was quite large antenna), ~140Mbit, so switching to 1/2 BPSK will make it ~16Mbit/s, which is pretty useless for telco purposes. For corporate, end-users, with QoS - it can be ok, but still depends on climatic zone. Remember, it is not downlink only issue, but uplink too. And depends on antenna elevation angle as well. Even for end-user it is not fun to have 1/10 of capacity, most likely means unable to do video conferencing anymore, for few days, just because it is few rainy days. And as Ku is often covering specific regions, often it means rainy days for most transponder customers. This is why in zones closer to equator, with their long-term monsoon, C-Band was only option, no idea about now.
The most noteworthy thing I'm seeing in C band these days, is many customers formerly 100% reliant upon it shifting their traffic to newly built submarine fiber routes. On Mon, Jul 6, 2020, 11:51 PM Denys Fedoryshchenko < nuclearcat@nuclearcat.com> wrote:
On 2020-07-07 08:32, Eric Kuhnke wrote:
"no clouds" is overstating the effect somewhat. I've operated a number of mission critical Ku band based systems that met four nines of overall link uptime. The operational effect of a cloud that isn't an active downpour of rain is negligible. Continual overcast of clouds is not much of a problem at all, it's active rain rate in mm/hour and its statistical likelihood, climate parameters of the location.
Yes, during rain fade events, current generation VSAT modems will drop all the way down to BPSK 1/2 code rate to maintain a link, with corresponding effect on real world throughput in kbps each direction, but entirely dropping a link is rare.
BPSK 1/2 is quite extreme. In my case it was 32APSK 8/9 at 36Mhz transponder (yes it was quite large antenna), ~140Mbit, so switching to 1/2 BPSK will make it ~16Mbit/s, which is pretty useless for telco purposes. For corporate, end-users, with QoS - it can be ok, but still depends on climatic zone. Remember, it is not downlink only issue, but uplink too. And depends on antenna elevation angle as well. Even for end-user it is not fun to have 1/10 of capacity, most likely means unable to do video conferencing anymore, for few days, just because it is few rainy days. And as Ku is often covering specific regions, often it means rainy days for most transponder customers. This is why in zones closer to equator, with their long-term monsoon, C-Band was only option, no idea about now.
On 7/Jul/20 10:07, Eric Kuhnke wrote:
The most noteworthy thing I'm seeing in C band these days, is many customers formerly 100% reliant upon it shifting their traffic to newly built submarine fiber routes.
Before most of Africa had submarine fibre, a lot of our traffic was carried on C-Band. In the decade preceding the arrival of submarine fibre, we reduced costs by moving to Inclined Orbit satellites, which were mainly operated on Ku-Band. So outages due to rain were a normal and accepted part of doing business. ISP's that maintained C-Band satellites survived rain fade, but had much higher operating costs. Nowadays, satellite services are generally used in remote locations, and for specific applications. Submarine fibre is the norm. Mark.
Watching the growth of terrestrial fiber (and PTP microwave) networks going inland from the west and east African coasts has been interesting. There's a big old C-band earth station on the hill above Freetown, Sierra Leone that was previously the capital's only link to the outside world. Obsoleted for some years now thanks to the submarine cable and landing station. I imagine they might keep things live as a backup path with a small C-band transponder MHz commit and SCPC modems linked to an earth station somewhere in Europe, but not with very much capacity or monthly cost. The landing station in Mogadishu had a similar effect. On Tue, Jul 7, 2020 at 1:45 AM Mark Tinka <mark.tinka@seacom.com> wrote:
On 7/Jul/20 10:07, Eric Kuhnke wrote:
The most noteworthy thing I'm seeing in C band these days, is many customers formerly 100% reliant upon it shifting their traffic to newly built submarine fiber routes.
Before most of Africa had submarine fibre, a lot of our traffic was carried on C-Band.
In the decade preceding the arrival of submarine fibre, we reduced costs by moving to Inclined Orbit satellites, which were mainly operated on Ku-Band. So outages due to rain were a normal and accepted part of doing business. ISP's that maintained C-Band satellites survived rain fade, but had much higher operating costs.
Nowadays, satellite services are generally used in remote locations, and for specific applications. Submarine fibre is the norm.
Mark.
On 7/Jul/20 21:58, Eric Kuhnke wrote:
Watching the growth of terrestrial fiber (and PTP microwave) networks going inland from the west and east African coasts has been interesting. There's a big old C-band earth station on the hill above Freetown, Sierra Leone that was previously the capital's only link to the outside world. Obsoleted for some years now thanks to the submarine cable and landing station. I imagine they might keep things live as a backup path with a small C-band transponder MHz commit and SCPC modems linked to an earth station somewhere in Europe, but not with very much capacity or monthly cost.
The landing station in Mogadishu had a similar effect.
The early years of submarine fibre in Africa always had satellite as a backup. In fact, many satellite companies that served Africa with Internet prior to submarine fibre were banking on subsea and terrestrial failures to remain relevant. It worked between 2009 - 2013, when terrestrial builds and operation had plenty of teething problems. Those companies have since either disappeared or moved their services over to fibre as well. In that time, it has simply become impossible to have any backup capacity on satellite anymore. There is too much active fibre bandwidth being carried around and out of/into Africa for any satellite system to make sense. Rather, diversifying terrestrial and submarine capacity is the answer, and that is growing quite well. Plenty of new cable systems that are launching this year, next year and the next 3 years. At the moment, one would say there is sufficient submarine capacity to keep the continent going in case of a major subsea cut (like we saw in January when both the WACS and SAT-3 cables got cut at the same time, and were out for over a month). Satellite earth stations are not irrelevant, however. They still do get used to provide satellite-based TV services, and can also be used for media houses who need to hook up to their network to broadcast video when reporting in the region (even though uploading a raw file back home over the Internet is where the tech. has now gone). Mark.
When we started TICSA (Internet Africa/Verizon/whatever), we went with a 9600 bps satellite link to New Jersey specifically because the SAT-2 fibre had just been installed and traffic was being moved off satellite. The satellite folk were getting *very* nervous, and gave us a heavily discounted service provided we had a 5-year contract that specified that they service *had* to run over satellite. Job insurance. As our requirements grew, we added fibre connections. Eventually the telco canceled the satellite connection as they were starting to focus on VSAT. paul
On Jul 8, 2020, at 3:05 AM, Mark Tinka <mark.tinka@seacom.com> wrote:
On 7/Jul/20 21:58, Eric Kuhnke wrote:
Watching the growth of terrestrial fiber (and PTP microwave) networks going inland from the west and east African coasts has been interesting. There's a big old C-band earth station on the hill above Freetown, Sierra Leone that was previously the capital's only link to the outside world. Obsoleted for some years now thanks to the submarine cable and landing station. I imagine they might keep things live as a backup path with a small C-band transponder MHz commit and SCPC modems linked to an earth station somewhere in Europe, but not with very much capacity or monthly cost.
The landing station in Mogadishu had a similar effect.
The early years of submarine fibre in Africa always had satellite as a backup. In fact, many satellite companies that served Africa with Internet prior to submarine fibre were banking on subsea and terrestrial failures to remain relevant. It worked between 2009 - 2013, when terrestrial builds and operation had plenty of teething problems. Those companies have since either disappeared or moved their services over to fibre as well.
In that time, it has simply become impossible to have any backup capacity on satellite anymore. There is too much active fibre bandwidth being carried around and out of/into Africa for any satellite system to make sense. Rather, diversifying terrestrial and submarine capacity is the answer, and that is growing quite well.
Plenty of new cable systems that are launching this year, next year and the next 3 years. At the moment, one would say there is sufficient submarine capacity to keep the continent going in case of a major subsea cut (like we saw in January when both the WACS and SAT-3 cables got cut at the same time, and were out for over a month).
Satellite earth stations are not irrelevant, however. They still do get used to provide satellite-based TV services, and can also be used for media houses who need to hook up to their network to broadcast video when reporting in the region (even though uploading a raw file back home over the Internet is where the tech. has now gone).
Mark.
On 8/Jul/20 15:21, Paul Nash wrote:
When we started TICSA (Internet Africa/Verizon/whatever), we went with a 9600 bps satellite link to New Jersey specifically because the SAT-2 fibre had just been installed and traffic was being moved off satellite. The satellite folk were getting *very* nervous, and gave us a heavily discounted service provided we had a 5-year contract that specified that they service *had* to run over satellite. Job insurance.
As our requirements grew, we added fibre connections. Eventually the telco canceled the satellite connection as they were starting to focus on VSAT.
There's no denying... they well-and-truly made their money :-). If I think back to what we paid for 192Kbps up, 320Kbps down, it may make all the grown folk on this list cry in :-). Mark.
On 2020-07-08 10:05, Mark Tinka wrote:
On 7/Jul/20 21:58, Eric Kuhnke wrote:
Watching the growth of terrestrial fiber (and PTP microwave) networks going inland from the west and east African coasts has been interesting. There's a big old C-band earth station on the hill above Freetown, Sierra Leone that was previously the capital's only link to the outside world. Obsoleted for some years now thanks to the submarine cable and landing station. I imagine they might keep things live as a backup path with a small C-band transponder MHz commit and SCPC modems linked to an earth station somewhere in Europe, but not with very much capacity or monthly cost.
The landing station in Mogadishu had a similar effect.
The early years of submarine fibre in Africa always had satellite as a backup. In fact, many satellite companies that served Africa with Internet prior to submarine fibre were banking on subsea and terrestrial failures to remain relevant. It worked between 2009 - 2013, when terrestrial builds and operation had plenty of teething problems. Those companies have since either disappeared or moved their services over to fibre as well.
In that time, it has simply become impossible to have any backup capacity on satellite anymore. There is too much active fibre bandwidth being carried around and out of/into Africa for any satellite system to make sense. Rather, diversifying terrestrial and submarine capacity is the answer, and that is growing quite well.
Plenty of new cable systems that are launching this year, next year and the next 3 years. At the moment, one would say there is sufficient submarine capacity to keep the continent going in case of a major subsea cut (like we saw in January when both the WACS and SAT-3 cables got cut at the same time, and were out for over a month).
Satellite earth stations are not irrelevant, however. They still do get used to provide satellite-based TV services, and can also be used for media houses who need to hook up to their network to broadcast video when reporting in the region (even though uploading a raw file back home over the Internet is where the tech. has now gone).
Mark.
I don't think traditional satellites have much future as backbone. Only as broadcasting media. Most are still acting as dumb RF converters, but we can't expect much more from them. On geostationary orbit, it is not only expensive to bring each additional kg, but also they need to keep it simple as possible, as it is all above van allen belt, and it needs to run there without any maintenance for 7+ years. So if SpaceX managed to squeeze in their satellites at least basic processing (and seems they did), it will improve satellite capabilities (and competitiveness) greatly. The only thing i hope, if they had space for some M2M IoT stuff, similar to ORBCOMM.
For the IoT/M2M stuff that doesn’t require huge amounts of data, there is a Silicon Valley startup that is deploying cube sats for just that. Swarm Technologies https://www.swarm.space/ -Mike
On Jul 8, 2020, at 19:49, Denys Fedoryshchenko <nuclearcat@nuclearcat.com> wrote:
On 2020-07-08 10:05, Mark Tinka wrote:
On 7/Jul/20 21:58, Eric Kuhnke wrote: Watching the growth of terrestrial fiber (and PTP microwave) networks going inland from the west and east African coasts has been interesting. There's a big old C-band earth station on the hill above Freetown, Sierra Leone that was previously the capital's only link to the outside world. Obsoleted for some years now thanks to the submarine cable and landing station. I imagine they might keep things live as a backup path with a small C-band transponder MHz commit and SCPC modems linked to an earth station somewhere in Europe, but not with very much capacity or monthly cost. The landing station in Mogadishu had a similar effect. The early years of submarine fibre in Africa always had satellite as a backup. In fact, many satellite companies that served Africa with Internet prior to submarine fibre were banking on subsea and terrestrial failures to remain relevant. It worked between 2009 - 2013, when terrestrial builds and operation had plenty of teething problems. Those companies have since either disappeared or moved their services over to fibre as well. In that time, it has simply become impossible to have any backup capacity on satellite anymore. There is too much active fibre bandwidth being carried around and out of/into Africa for any satellite system to make sense. Rather, diversifying terrestrial and submarine capacity is the answer, and that is growing quite well. Plenty of new cable systems that are launching this year, next year and the next 3 years. At the moment, one would say there is sufficient submarine capacity to keep the continent going in case of a major subsea cut (like we saw in January when both the WACS and SAT-3 cables got cut at the same time, and were out for over a month). Satellite earth stations are not irrelevant, however. They still do get used to provide satellite-based TV services, and can also be used for media houses who need to hook up to their network to broadcast video when reporting in the region (even though uploading a raw file back home over the Internet is where the tech. has now gone). Mark.
I don't think traditional satellites have much future as backbone. Only as broadcasting media. Most are still acting as dumb RF converters, but we can't expect much more from them. On geostationary orbit, it is not only expensive to bring each additional kg, but also they need to keep it simple as possible, as it is all above van allen belt, and it needs to run there without any maintenance for 7+ years. So if SpaceX managed to squeeze in their satellites at least basic processing (and seems they did), it will improve satellite capabilities (and competitiveness) greatly. The only thing i hope, if they had space for some M2M IoT stuff, similar to ORBCOMM.
Proprietary startups for M2M in most of cases bad idea, especially if they require custom hardware (those operate in VHF band). And with such history: <<Originally in March of 2018, Swarm had launched satellites without FCC approval. In December of 2018, Swarm agreed to pay the FCC a total of $900k over five years for the unauthorized launch. The company began bouncing back, as it closed a Series A financing round with $25 million in January.>> https://www.satellitetoday.com/government-military/2019/10/18/swarm-receives... Here is example, Sigfox in UK seems powered by startup, and startup went defunct: https://twitter.com/cybergibbons/status/1280892048787243008 And my own experience, if you embed in your design proprietary modem, it will be very pricey to replace it, if startup fail to reach profit margin. I rather will trust technologies based on open standards, like FossaSat or Lacuna, often they are built with terrestrial fallback, and in fact you can build your own gateways, if required. And more than that, some modules, like Murata, support both Sigfox + LoRaWAN, and technically possible to support LoRa satellites as well at same time, without significant hardware mods. On 2020-07-09 05:56, Mike Lyon wrote:
For the IoT/M2M stuff that doesn’t require huge amounts of data, there is a Silicon Valley startup that is deploying cube sats for just that.
Swarm Technologies
-Mike
On 9/Jul/20 04:47, Denys Fedoryshchenko wrote:
I don't think traditional satellites have much future as backbone. Only as broadcasting media.
Does anyone know of (m)any satellite TV services delivering 1080p or greater? The most I've seen on our side of the rock is 1080i. If there is an inherent commercial restriction in how many pixels we can grab over satellite at scale, it might be tricky for some markets that demand 1080p, 4K, or greater, for linear TV. Mark.
On 09/07/2020 05:34, Mark Tinka wrote:
Does anyone know of (m)any satellite TV services delivering 1080p or greater? The most I've seen on our side of the rock is 1080i.
If there is an inherent commercial restriction in how many pixels we can grab over satellite at scale, it might be tricky for some markets that demand 1080p, 4K, or greater, for linear TV.
Mark.
There are a few 4K test streams. NASA TV is one: https://www.lyngsat.com/tvchannels/us/NASA-TV-UHD.html I just piped it into ffmpeg and the NASA TV feed runs 10-15mbps, H.265 encoding at a resolution of 3840x2160. So definitely possible to push greater then 1080 video. Chris
On 9/Jul/20 16:51, Christopher Munz-Michielin wrote:
There are a few 4K test streams. NASA TV is one:
https://www.lyngsat.com/tvchannels/us/NASA-TV-UHD.html
I just piped it into ffmpeg and the NASA TV feed runs 10-15mbps, H.265 encoding at a resolution of 3840x2160. So definitely possible to push greater then 1080 video.
So is there a reason why we are not seeing widespread 1080p TV via satellite? They seem to exist where a broadcaster also supports an IPTV platform. Mark.
On 09/07/2020 08:00, Mark Tinka wrote: So is there a reason why we are not seeing widespread 1080p TV via satellite? They seem to exist where a broadcaster also supports an IPTV platform.
Mark. I'd assume it's a question of available bandwidth and availability of decoders. From my observations most HD satellite feeds seem to sit between 3 and 5 mbps, a typical Ku band transponder might have a bandwidth of around 20-25mbps. This means you can cram 5-8 HD feeds onto a single transponder. With 4K streams the bandwidth requirements double, meaning you can cram a lot less in the same amount of transponder space and satellite bandwidth is expensive!
The other issue is on the decoder side. Right now, the vast majority of satellite subscribers receive programming though dedicated decoders (set top boxes). Most of these decoders only have hardware to decode MPEG2 and H.264 video, while 4K stuff is almost exclusively H.265. That means it's not a simple matter of turning on 4K, you'd have to arrange to send new decoders to all your subscribers wanting to receive 4K. As time moves along, I'm sure we'll start to see more satellite feeds available in 4K but like the transition to HD video, it'll be a slow process. Chris
On 9/Jul/20 18:00, Christopher Munz-Michielin wrote:
I'd assume it's a question of available bandwidth and availability of decoders. From my observations most HD satellite feeds seem to sit between 3 and 5 mbps, a typical Ku band transponder might have a bandwidth of around 20-25mbps. This means you can cram 5-8 HD feeds onto a single transponder. With 4K streams the bandwidth requirements double, meaning you can cram a lot less in the same amount of transponder space and satellite bandwidth is expensive!
The other issue is on the decoder side. Right now, the vast majority of satellite subscribers receive programming though dedicated decoders (set top boxes). Most of these decoders only have hardware to decode MPEG2 and H.264 video, while 4K stuff is almost exclusively H.265. That means it's not a simple matter of turning on 4K, you'd have to arrange to send new decoders to all your subscribers wanting to receive 4K.
As time moves along, I'm sure we'll start to see more satellite feeds available in 4K but like the transition to HD video, it'll be a slow process.
The above are all the reasons I've been positing as well. It's just that with more and more stuff being loaded on to IP (not to mention, good ol' IPTV), does it make sense for broadcasters to upgrade satellite infrastructure and decoders to support 1080p, 4K, 8K, 16K, e.t.c., when all you need is an app and an Internet connection for the very same (if not better) quality? Not to mention, considerations for eyeball time in the fight between the linear TV and VoD? Mark.
Mark Tinka wrote:
It's just that with more and more stuff being loaded on to IP (not to mention, good ol' IPTV),
Good.
does it make sense for broadcasters to upgrade satellite infrastructure and decoders to support 1080p, 4K, 8K, 16K, e.t.c., when all you need is an app and an Internet connection for the very same (if not better) quality?
There is a jump of logic. First, we should have STBes to generate not decoded video signal over HDMI but encoded video over IP over Ethernet. Though IP packets may be carried to anywhere, which makes regional restrictions meaningless, (re-encoded) decoded video can be carried by IP anyway. We should also use IP even over radio waves. IP over MPEG2-TS over DVB (or terrestrial broadcast network) is doable though IP directly over DVB should be better.
Not to mention, considerations for eyeball time in the fight between the linear TV and VoD?
Unicast video over satellite link costs a lot. Masataka Ohta
On 9/Jul/20 22:49, Masataka Ohta wrote:
We should also use IP even over radio waves. IP over MPEG2-TS over DVB (or terrestrial broadcast network) is doable though IP directly over DVB should be better.
Well, when we moved over from traditional satellites to inclined orbit satellites back in 2000 across most of Africa, IP was carried directly over DVB for downlink traffic. The uplink traffic still required regular SCPC modems. We had to use a DVB decoder reconfigured for IP carriage (rather than video) to decode the DVB stream (via a unique key, since DVB is a Multicast-type medium) and pass the IP packets over to your router. So yes, this technology does exist, and is way cheaper than SCPC in the downlink direction.
Unicast video over satellite link costs a lot.
Which is my point, and makes me wonder whether we shall ever see 1080p or greater via satellite, en masse. DVB, however, is more Multicast-y. So technically, you aren't unicasting video over DVB, which is what a number of satellite TV providers are using to deliver their services. Mark.
With common Ku band TVRO (receive only) dishes and decoders, one of the constraints for moving to higher bitrates is the physical sizes of the customer dish and economics. For a good example go to a very densely populated developing nation environment. Saddar, central Rawalpindi, Pakistan would be one such place. Get up on a tall roof and look at the numerous low cost Ku dish and LNB setups on other roofs. Achievable bps/Hz and modulation type, code rates, and type of FEC are very limited when the antenna has to be so small. Usually something like qpsk 3/4. In order to have something like a 4k stream and not require end users to replace their 75-100cm size dishes with something much bigger, you'd need to use a lot more MHz on the geostationary satellite's transponder. Greatly increasing monthly transponder fees for the tv broadcaster. Any sort of modulation like 8PSK or a 16QAM is probably not achievable as long as the end user consumer antennas remain so small. For people who are accustomed to a terrestrial microwave link budget and path loss, Geostationary will seem weird. For SCPC two way data links you can spend a lot of money and construct 3.8-4.5m size earth stations, definitely a construction project with a capital P, but the laws of physics will dictate your link sees only 4 bps/Hz or less. Even with the very best modems on the market now. Ultimately advances in codecs may help this somewhat. 4k AV1 at fairly low bitrates is remarkably not terrible. H.266 was just standardized. It'll take a long time for full hardware decode to show up in ultra low cost satellite TV boxes. On Thu, Jul 9, 2020, 9:01 AM Christopher Munz-Michielin < christopher@ve7alb.ca> wrote:
On 09/07/2020 08:00, Mark Tinka wrote: So is there a reason why we are not seeing widespread 1080p TV via satellite? They seem to exist where a broadcaster also supports an IPTV platform.
Mark. I'd assume it's a question of available bandwidth and availability of decoders. From my observations most HD satellite feeds seem to sit between 3 and 5 mbps, a typical Ku band transponder might have a bandwidth of around 20-25mbps. This means you can cram 5-8 HD feeds onto a single transponder. With 4K streams the bandwidth requirements double, meaning you can cram a lot less in the same amount of transponder space and satellite bandwidth is expensive!
The other issue is on the decoder side. Right now, the vast majority of satellite subscribers receive programming though dedicated decoders (set top boxes). Most of these decoders only have hardware to decode MPEG2 and H.264 video, while 4K stuff is almost exclusively H.265. That means it's not a simple matter of turning on 4K, you'd have to arrange to send new decoders to all your subscribers wanting to receive 4K.
As time moves along, I'm sure we'll start to see more satellite feeds available in 4K but like the transition to HD video, it'll be a slow process.
Chris
On 10/Jul/20 10:50, Eric Kuhnke wrote:
With common Ku band TVRO (receive only) dishes and decoders, one of the constraints for moving to higher bitrates is the physical sizes of the customer dish and economics.
For a good example go to a very densely populated developing nation environment. Saddar, central Rawalpindi, Pakistan would be one such place. Get up on a tall roof and look at the numerous low cost Ku dish and LNB setups on other roofs.
Achievable bps/Hz and modulation type, code rates, and type of FEC are very limited when the antenna has to be so small. Usually something like qpsk 3/4. In order to have something like a 4k stream and not require end users to replace their 75-100cm size dishes with something much bigger, you'd need to use a lot more MHz on the geostationary satellite's transponder. Greatly increasing monthly transponder fees for the tv broadcaster. Any sort of modulation like 8PSK or a 16QAM is probably not achievable as long as the end user consumer antennas remain so small.
For people who are accustomed to a terrestrial microwave link budget and path loss, Geostationary will seem weird. For SCPC two way data links you can spend a lot of money and construct 3.8-4.5m size earth stations, definitely a construction project with a capital P, but the laws of physics will dictate your link sees only 4 bps/Hz or less. Even with the very best modems on the market now.
Ultimately advances in codecs may help this somewhat. 4k AV1 at fairly low bitrates is remarkably not terrible. H.266 was just standardized. It'll take a long time for full hardware decode to show up in ultra low cost satellite TV boxes.
When the leading satellite TV provider in Africa first started delivering service via satellite back in 1997, it was on C-Band, with the smallest dish needing to be 2.4m. When they moved to Ku-Band around 2010, every home now has 90cm dishes. While they do say 60cm dishes are viable, you won't be able to pick up any HD service with those. Mark.
On 7/Jul/20 08:51, Denys Fedoryshchenko wrote:
And as Ku is often covering specific regions, often it means rainy days for most transponder customers. This is why in zones closer to equator, with their long-term monsoon, C-Band was only option, no idea about now.
In much of Africa, the largest satellite TV provider has been running on Ku-Band into homes for several years now. I'm not sure if they still support C-Band services for specialized requirements. But all consumers have been on Ku-Band for a while now. Heavy rain does cause outages, but overcasts do not. If you are lucky to have an FTTH service and you are hit with rain, you can turn to their app and stream the same live channels while the rain falls. Mark.
participants (12)
-
Christopher Munz-Michielin -
Denys Fedoryshchenko -
Eric Kuhnke -
Harry McGregor -
j k -
james jones -
joe mcguckin -
Mark Tinka -
Masataka Ohta -
Mike Lyon -
Paul Nash -
Saku Ytti