EPG slow to populate
[Deleted User]
Posts: 63
Forum Member
✭
Hi,
Wonder if anybody can help with this please.
My friend and I have identical set-ups - an LG 36" TV and a Humax 9150.
We are on the same transmitter - Crystal Palace.
My EPG populates so quickly when I turn on my TV/Humax that I rarely, if ever, have to wait for it.
My friend's can take anything up to an hour to populate for a few days ahead, and even the current day is frustratingly slow.
Can anybody suggest what might be causing this and how it can be sorted.
TIA
Wonder if anybody can help with this please.
My friend and I have identical set-ups - an LG 36" TV and a Humax 9150.
We are on the same transmitter - Crystal Palace.
My EPG populates so quickly when I turn on my TV/Humax that I rarely, if ever, have to wait for it.
My friend's can take anything up to an hour to populate for a few days ahead, and even the current day is frustratingly slow.
Can anybody suggest what might be causing this and how it can be sorted.
TIA
0
Comments
The problem turned out to be the fact that she kept turning off the Humax - I think she's convinced that it's costing her a fortune to leave it switched on and/or her home will catch fire if the Humax is not switched off! She still turns it off but at least now is aware that she'll have to wait for the EPG once she turns it on.
With now and next ( present and future. In DVB speak ) for this mux transmitted more frequently that P/F other muxes, then a few hours(or rest of day) this mux ... Through to 7 days ahead other muxes in increasingly less frequent repetition .
So you can see all P/F in about 20 seconds .... But it should do most of the 7 days in say half an hour or so ... Which can over write any historic and thus update info from the hard drive....
The number Of carousel of data is probably at least 8 ....
For DSAT there is a default transponder which has about 40 times the bit rate of the DTT trickle and thus can download far quicker and efficiently often using the second feed.
Thee is also a P/F feed on each transponder
The UK D Book for DTT requires the broadcasters to achieve EPG table repetition rates as specified by DVB in ETSI Guidelines document TR 101 211.
TR 101 211 specifies maximum (terrestrial) repetition rates for EIT schedule actual (that's the full EPG for the current mux you're tuned to) of 10s for the first full day of schedule and 30s for the entire schedule.
The maximum rates for EIT schedule other (that's the full EPG for all the muxes you're not tuned to) are 60s for the first full day of schedule and 300s for the entire schedule.
That makes the maximum permitted EIT repetition time 5 minutes (for the full EPG), and the BBC run the system well within those limits.
It used to be widely reported that the Humax SD PVRs required two cycles of the data carousel to fully populate the EPG.
Recently a thread on here reports that the Humax SD PVRs fail to retain a complete EPG for days 4 to 8 with random gaps present. on all channels.
Colin
May as well be speaking french.
Actually RT102 211 cannot specify anything because it is not s specification
But putting that to one side ...
Section 4.4.2 defines in one list the repetition frequencies of the main tables
which end up with EIT P/F this mux at 2 seconds and P/F others at 20 secs
It then goes on to indicate what rates the Further part of EIT should be transmitted
but the numbers are highly qualified
which to summarise are
Today This mux 10 secs
Today other mux 60 secs
Obviously these are of variable lengths as the event are rolled up so there is 24 hours worth at 00;01 and a minutes worth at 23:59
But on the whole these are met .. and with evening viewing can be quicker for some muxes! ( but there is a trade off with Tomorrow's Listings)
But then the this mux rest and Other mux rest are very verbose and thus take longer to transmit - and that is where my typical figures come from .... as there are a number of different carousels .... to optimise the limited bit rate ...
Just think - if one day takes 10 secs then at the same data rate 6 days will take 60 secs... not the 30 secs in TR102 211
I don't know what the current parameters are for DigitalUK service and in any case each mux has both different amount of data to carry in each Carousel - and a different amount of bit rate allocated to the SI.
But like the BBC did with Ceefax pages 601-5 they repeat things faster than other muxes .
But 20 mins is longer than most cycles .... pershaps 5 mins up to 10 min is more reasonable - for the full EPG
but some PVRs are better than other that picking things up first time round.
If you want to look at some of the issues I suggest you look at the Teletext EPG ETS 300 707 - and its accompanying CoP TR288 give a simple expansion of some of the issues - But you need t realize that it works on spare spaces in the Teletext stream - which is typically a few Kbit/sec rather than the 1 to 2 Mbit/sec avail in the DVB world.
one interesting point is that this Spec enables not just P/F but also now next and next +1 (or even more) as the most frequent transmission ...
this was done to get over the problem that can come up if you are turning on just before the hour - you can then see the "On the hour" and "next programme (at Half past) " almost immediatly.
I have noticed a few times when viewing in the evening, that the EPG which had a full 8 days worth for all channels, deletes large swathes of itself.
For example, I can be viewing the listings for channel 8 onwards (8 BBC Alba, 9 BBC Four, 10 ITV3, 11 Pick, etc.). Usually, I'm tuned to a BBC channel whilst viewing the EPG.
Suddenly, ITV3, Pick, Dave, Channel 4+1, etc. will disappear. Eventually the deletions are filled in again.
What is the reason for this?
Can DigitalUk upgrade the EPG carousel speeds? A 10 Day EPG would be of more value to me. I notice that the HDR-T2 has space for a second week.
It is the EIT Schedule data which is used by receiving devices to compile the EPG.
I'm still trying to get my head round your post #11. I'm intending to test the EPG population time on a PVR which I know populates fully from one cycle of the EPG Schedule carousel. This will test if this is less than 5 min which applied when I last tested this. I will then be in a position to prepare a more informed reply to your post #11.
Colin