MacLeech
The one and only
Premium
join:2001-07-14
SoCal
| reply to spfaff
Re: Wasteful Channel Lineup means fewer HD Channels?
said by spfaff :
750/6 = 125 and 860/6 = ~143,... what happened to the remaining 8 slots each ? Check the included list for a standard "slot" layout with frequencies.
There are gaps in the slot arrangement to make room for certain other users.
--
Don't mind me, I'm just trying to help...
|
|
cypherstream
Looking forward to the future of things.
Premium,MVM
join:2004-12-02
Reading, PA
clubs: | reply to spfaff
Subtract 54 first. The first 54 MHz is the return path.
750-54 = 696.
696 / 6 = 116. There's no issues putting at least one or two channels over, so add one for 117. (Don't add 2 because ch 1 doesn't count). |
|
spfaff
@comcast.net
| reply to cypherstream
said by cypherstream  :I'm going to try to use the term Slots instead of channels to try not to get confused. A slot is this description is a 6 MHz wide "RF Channel". In a 750 MHz system there are 117 "Slots". In an 860 MHz system there are 135 "Slots". 750/6 = 125 and 860/6 = ~143,... what happened to the
remaining 8 slots each ? |
|
bicker
join:2007-05-10
Burlington, MA | reply to IPPlanMan
The most reliable information I've read regarding some systems around here which have three slots available is that engineering is where the delay is. (And that's all the details I have about it.) |
|
IPPlanMan
Holy Cable Modem Batman
join:2000-09-20
Washington, DC | reply to heat84
I Googled for "Comcast D.C. 860 MHz" and came up with that link... Might be able to do the same for your area. |
|
IPPlanMan
Holy Cable Modem Batman
join:2000-09-20
Washington, DC | reply to markofmayhem
Wow... That's very helpful
Thanks for doing the Math... Must be a "contractual" issue or something holding up the new channels then if they've got room.... Thoughts? |
|
keithbart
join:2007-01-01
South Bend, IN | reply to IPPlanMan
My system is 860MHz but I have never heard of a 1GHz
system. Boston maybe? |
|
heat84
join:2004-03-11
Fort Lauderdale, FL | reply to cypherstream
When did Comcast start upgrading to 860MHZ and 1GHZ? |
|
cypherstream
Looking forward to the future of things.
Premium,MVM
join:2004-12-02
Reading, PA
clubs: | reply to heat84
My system was upgraded 10 years ago (at least my neighborhood) and it's still only 750 MHz from that day. Back in 1998 when we switched over to the 750 MHz, it felt state of the art coming from a 450 MHz one way system. |
|
heat84
join:2004-03-11
Fort Lauderdale, FL | reply to IPPlanMan
Is there anyway to find out what my system is? It was upgraded 10 years ago, so I guess its 860MHZ. |
|
cypherstream
Looking forward to the future of things.
Premium,MVM
join:2004-12-02
Reading, PA
clubs:
| reply to markofmayhem
Yeah that was the problem with Harrisburg and Hershey's 860 area's up until recently. The majority of Central PA is 750 MHz. They did some work in Harrisburg and Hershey to help 'break them away' from the gridlock that was holding them back from the rest of CPA.
D.C. is 860 though if you read that Multichannel News article that was posted above. Makes sense, you want to have a good high tech system around capital hill. |
|
markofmayhem
join:2004-04-08
Pittsburgh, PA
| reply to keithbart
Chicago and Boston were easy, DC is not.
»hraunfoss.fcc.gov/edocs_public/a···24A1.pdf
Go to your state and county, this is a list of the channels that Satellite must carry as local in your area (it's an easy document to read and VERY closely mirrors the required stations that Comcast must carry as well: use it as a "cheat-sheet"). As long as these channels apply for "must carry" ATSC licenses and check "analog support" until 2012, they will remain analog as well as your "local" stations. DC is a pretty flooded by surrounding markets. Areas close in Maryland, Virginia, and Delaware will more than likely have closer to 30 analog stations carried after an "all digital" transition.
DC is also big on ingress due to RF waves all over the skies. There's probably a few channels skipped on your plant. If your truly estimating:
Count your total analog stations today, 68 as Cypher said.
Estimate 22 channels for 232 SD channels, half at 12:1 and half at 10:1 (the 15:1 and 8:1 will cancel each other out).
Estimate 6 3:1 HD HITS and local muxed stations (18 HD's)
Estimate 10 channels for the other 20 HD stations: locals and nationals such as HDTheatre and the ESPN's
Estimate 1 full channel of music.
Estimate 6 digital services channels (VoD, HSI, and the like).
Estimate 4 unservicable channels.
Estimate 1 OOB support channel.
That's 118, just one over a "normal" 750mhz system. You may be "860", doesn't mean your utilizing it all. Looks like a jam-packed 750 system to me. Being DC, I'm sure you have tons of traps and filters on your system in addition to out-dated and damaged taps. Perhaps replacing them all for releasing that full 860 potential is not cost effective. Your physical plant connected to your home may support 860; your entire node may support 860; but you have to get your entire head-end on board. Also, if your head-end is not able to receive national channels on it's own, then your at the mercy of your regional head-end to feed you those new national HD channels. If the regional head-end has mostly 750mhz plant on it's system, then your maxed out and looking at analog reclaimation as your solution for more HD. I feel your pain, I have a carrier test signal on channel 131, CLEARLY able to handle 860mhz on my plant, but am stuck on a line-up for 650mhz systems, slightly less than you. If you truly are 860 and it's not capacity stopping you but the regional VP to light up your area before other less capacity areas, then you have room for:
Dedicated VoD slots to handle: 17 additional HD feeds + 51 additional SD feeds
34 HD at 2:1 compression
51 HD at 3:1 compression
170 SD at average compression (10:1 is average)
2040 music express channels |
|
keithbart
join:2007-01-01
South Bend, IN | reply to IPPlanMan
The reason I counted 46 is when Comcast does an analog migration (like they did in Chicago) they keep about
20 stations(locals like ABC, CBS, etc.) on analog. |
|
cypherstream
Looking forward to the future of things.
Premium,MVM
join:2004-12-02
Reading, PA
clubs:
| reply to keithbart
I thought I counted 58 analogs on TV Planner.net for your zip code. Well it's hard to say, some of those numbers 'below 100' could actually be digital only.
There's a lot of factors at play there. How many channels total (not including duplicates that show up in the lineup). 4 Music Choice channels count as 1 SD Digital channel.
Say you do have 46 analog channels. In an 860 MHz system you have 135 available channel slots. That's 89 channel slots available for digital channels and data. Conservatively let's say 6 channel slots for VOD and 2 for HSI/CDV. That's 81 channel slots for digital video. If they are only doing 2:1 HD compression since they have the room, that's 19 slots used for your current HD lineup. Could be less if they have some 3:1 compression in use. Normally there is a mix (some 3:1, some 2:1).
Anyway that's 62 channel slots available. Remember we have to duplicate your lineup now in the digital form. So count all of your SD channels from 2 to 999 but don't count duplicates and don't count HD (we've already accounted for them). Also don't worry about music only channels.
Take that answer and divide it by 12. Now add one for the Music Choice. Whatever that answer is minus 62 is a "rough estimate" of how much free space could be left.
Remember they could be using 10:1 compression, 11:1, or 12:1 on SD channels. Many times there's a mix mash. Some 15:1 (MLB/NHL Package), some 6:1 (ESPN PPV), some 8:1, some 10:1, etc....
Minus whatever channels you can't use due to noise, OTA interference, or placement of OOB data channels. If your system is smart, your OOB channel will be in the 74~75 MHz range between analog channels 4 and 5. If not, it could possibly live in the way of ch 95,96,97,98 or 99. Some area's designed the system better than others.
I would imagine you have enough room for 70 HD channels at least (with 2:1 compression). |
|
keithbart
join:2007-01-01
South Bend, IN | reply to IPPlanMan
cypherstream, I have 38 HD channels and 46 non-local
analogs on my 860MHz system. Can you give me a rough idea how many new HD channels Comcast can add? Thanks. |
|
cypherstream
Looking forward to the future of things.
Premium,MVM
join:2004-12-02
Reading, PA
clubs:
| reply to IPPlanMan
Nope, you are 860 MHz system, your good to go.
I have 33 HD channels on a 750 MHz system, along with the standard Comcast fanfare, plus 1 data channel and 4 VOD channels (Some nodes are using 6 VOD channels). We have 74 analogs as well and we can't use slot #97 because the Motorola OOB data channel is there.
You have an extra 110 MHz to play with. |
|
IPPlanMan
Holy Cable Modem Batman
join:2000-09-20
Washington, DC
3 edits | reply to IPPlanMan
38... not counting the Pay-per-view HD or HD on Demand Channels
Cypherstream- Using your math, are they running out of space to offer more here in DC? |
|
keithbart
join:2007-01-01
South Bend, IN
| reply to IPPlanMan
My system is 860MHz and I have 38 HD channels. How many do you have? |
|
IPPlanMan
Holy Cable Modem Batman
join:2000-09-20
Washington, DC | reply to IPPlanMan
I did some looking and it turns out that Comcast D.C. is an 860 MHz system...
»www.multichannel.com/article/CA625894.html |
|
jmoz2989
join:2008-02-01
Moscow, PA
 ·Adams CATV
| reply to cypherstream
Comcast recently took over a 500 Mhz system in Eagles Mere and Northumberland, PA. The company that ran these systems was Commuter Cable, like a lot of the rural providers in northern PA, they never invested in network upgrades for extra services. So now Comcast has a system with no digital cable infrastructure, HSI or digital voice solution. This is one system that Comcast has to sell off to Blue Ridge or Metrocast which already have a presence in that area. Otherwise none of these older Adelphia systems or ones in southeast PA will never be up to par, due to Comcast purchasing these legacy systems and experimenting with things like targeted advertising. |
|
