Draft FAQ - Scanning for Services

[prl]

UPDATE (Sep 2010):
The latest firmware versions (from 01.05.334 & 01.07.055) are intended to handle duplicate channels correctly as per The Free TV Australia Operational Practice OP-41 Logical Channel Descriptor. However, in some locations it selects the lower quality channels to use. In this case, clearing all services and using the appropriate partial scans (as in Dealing with duplicate services/Avoiding duplicates below) will force the use of the correct transmitter sites.

Scanning for Services
How do I know whether I have duplicate services
What problems do duplicate services cause?
Sounds a bit of a mess. Can't it be made easier?
Dealing with duplicate services
Removing duplicates
Avoiding duplicates
A worked example
Removing duplicates
Avoiding duplicates
How do I find out what transmitters I can receive from?


Scanning for Services

Normally, scanning for services on the Beyonwiz is simple. Just go to Setup > Config. > Service Scan; Scanning Range = FULL, and then Start Scanning.

However, a full scan is slow, and can be made faster in some cases by using Scanning Range = PARTIAL.

In other cases, you may be receiving the same digital TV services from different transmitters on different channels (I use "service" and "channel" here as described in peteru's note in the Reception FAQ). If you do a full scan and have duplicate service definitions, this can cause a number of problems with setting timers and other functions on the Beyonwiz.

A "service" as peteru describes it, has a Logical Channel Number (LCN), which is its identity in the Digital TV system. These numbers are different from the channel number, which identifies which part of the radio spectrum that a broadcast is made on. The same broadcaster (e.g. ABC) broadcasts on many different channels, depending on the transmitter. However, LCN 2 is always the digital service ABC1.

The aim of the FAQ is to describe what you need to do to avoid duplicate services, and to remove them if you have them. It will also, along the way, show how you can, in many circumstances, speed up a service scan by using a partial scan, and also point you to some resources for finding out what channels you are receiving from.

How do I know whether I have duplicate services

"Duplicate services" here doesn't mean seeing the same content on two different services (or LCNs). For example, ABC1 is normally transmitted on both LCN 2 and LCN 21.

By "duplicated services", I mean that your All Services list (press LIST in live TV and then BLUE for All Services), that there are two entries for ABC1 on LCN 2, on different channels (and different frequencies).

The Services list is a scrollable list that shows each scanned LCN and the service name it represents. At the bottom left of the services list, the broadcast channel number and the frequency of the channel carrying the service. A broadcast channel carries a number of services, both video and radio (audio only). At the moment only SBS and ABC channels carry radio services.

Duplicate services are services where the same LCN is repeated and associated with more than one different broadcast channel number. The service name can be repeated without the service being a duplicate service. For example, ABC1 is associated with LCN 2 and LCN 21. That is normal, and is not considered a duplicate service. ABC1 appearing twice on LCN 2 is a duplicate service.

What problems do duplicate services cause?

So, why should I care about duplicate services? After all, I can just set up one set in the Favorites and only use them, as I do with, say the ABC1 on LCN 2 and LCN 21.

Duplicate services (duplicate LCNs) can cause a variety of problems on the Beyonwiz. These include:

• The Beyonwiz selecting the weaker of the two channels to use, giving poor reception when the signal from the stronger transmitter is very good.
• Failure of the EPG to display correctly, with services visible in live TV missing EPG information. This can affect both Free-to-Air EPG and IceTV Guide.
• Timers failing to record correctly.
• When changing channels while dual recording, the tuner selection algorithm can be confused by the duplicate channels and may alter the tuner of one of the recordings mid-stream, causing recordings to cut short and/or get parts of a different service in them.

Sounds a bit of a mess. Can't it be made easier?

The Free TV Australia Operational Practice OP-41 Logical Channel Descriptor sets out quite clearly what a digital TV receiver should do if it receives duplicate services on more than one broadcast channel:

3.2.3 Signal Quality Matrix
If competing duplicate services (i.e. those that have the same LCN allocated) are received from different transmitters, then a receiver that complies with the Australian DVB-T receiver standard, AS 4933 [5], will place the service with the highest received quality in the correct LCN position and the other(s) made available to the user, for example stored at the next available unallocated number in the range 350 - 399, unless it is intentionally duplicated by the broadcaster as indicated by its presence in the frequency list descriptor of the NIT (see section 3.2.2), in which case it can be safely discarded.

Unfortunately, Beyonwiz PVRs don't implement this strategy, so you need to perform this process manually.

UPDATE (Sep 2010):
The latest firmware versions (from 01.05.334 & 01.07.055) are intended to handle duplicate channels correctly as per The Free TV Australia Operational Practice OP-41 Logical Channel Descriptor. However, in some locations it selects the lower quality channels to use. In this case, clearing all services and using the appropriate partial scans (as in Dealing with duplicate services/Avoiding duplicates below) will force the use of the correct transmitter sites.

Dealing with duplicate services

There are two ways of managing duplicate services, either do a full scan and then remove all the duplicated services, or, clear all the services, and then use a partial scan (or a number of partial scans) you ensure that you only scan one channel for each broadcaster.

Removing duplicates

• Make a note of your Favorite services lists and all your timers, especially if you use manual timers.
• Use LIST, BLUE All Services to see all services in the service list menu.
• Find all the duplicate service LCNs, and note down the broadcast channels that the services are associated with. For each duplicated LCN, you'll find a different broadcast channel number.
• Pick one representative service from each broadcast channel that's causing duplicate LCNs and change to the service in the Services LIST. Then use POPUP>Tuner Information and make a note of the Signal Strength and Signal Quality for each broadcast channel causing duplicated services.
• Choose the channel you want to keep from each set of duplicates. This will usually be the one with the best Signal Strength/Signal Quality, but if two channels have similar signal strength and quality, then simply choose the one you prefer (e.g. possibly a metropolitan and regional transmitter for the same network; Seven vs Prime, for example).
• Delete all the services associated with the channels you don't want to keep (YELLOW Delete button in LIST). Use the Radio/TV button to check radio services as well as TV services. Duplicated radio services need to be deleted, too.
• Check the service list for duplicates or other errors (have you deleted more services than you intended). If you've deleted too many services, you may want to do the rescan method suggested in the next section.
• Re-create any lost timers. If you use IceTV, go to My Account>Interactive in your IceTV account Web page and Resend All Timers for the device. Fix your Favorites lists.
• Re-select your Favorites list.

For emphasis, to remove problems caused by duplicate services, you have to remove all services TV and Radio associated with the broadcast channel you are trying to remove. You can't pick-and-choose services between two channels to give a set of "non-duplicates". You have to systematically remove all the duplicated services from all broadcast channels except the one you want to keep.

Avoiding duplicates

This method can also be useful for speeding up scans even if you don't have problems with duplicates. For example, the Black Mountain transmitters in the ACT transmits digital TV on channels 6 (SC Ten), 9A (ABC), 11 (WIN), 12 (Prime), and 30 (SBS). By doing a PARTIAL scan from channel 6 to channel 30 (the range is inclusive, so channels 6 and 30 will both be scanned), you can speed up your scan considerably, by scanning only 13 channels out of 52. This is possible to do in many locations, but the channels and scan ranges will be different.

• Make a note of all your timers, especially if you use manual timers.
• Use LIST, BLUE All Services to see all services in the service list menu.
• Find all the duplicate service LCNs, and note down the broadcast channels that the services are associated with. For each duplicated LCN, you'll find a different broadcast channel number.
• Pick one representative service from each broadcast channel that's causing duplicate LCNs and change to the service in the Services LIST. Then use POPUP>Tuner Information and make a note of the Signal Strength and Signal Quality for each broadcast channel causing duplicated services.
• Choose the channel you want to keep from each set of duplicates. This will usually be the one with the best Signal Strength/Signal Quality, but if two channels have similar signal strength and quaility, then simply choose the one you prefer (e.g. possibly a metropolitan and regional transmiter for the same network; Seven vs Prime, for example).
• Work out a channel range, or small set of channel ranges that will include all the channels you want to keep, and not include the channels you don't want to keep.
• In SETUP>System>Initialize, Clear Service Information.
• In SETUP>Config>Service Scan, use Scanning Rnge: PARTIAL and set Start Channel and End Channel to the first and last channels of one of (or the only) the ranges of channels you want to include. Repeat this step for other ranges if you need to.
• Check the service list to ensure you have the service coverage you want with no duplicates.
• Re-create any lost timers. If you use IceTV, go to My Account>Interactive in your IceTV account Web page and Resend All Timers for the device. Fix your Favorites lists.
• Re-select your Favorites list.

Once you've worked out which channel ranges to scan to avoid having duplicates, this is the simplest method to use if you ever need to clear all your services and rescan.

A worked example

In Adelaide, there are three digital TV transmitter sites.
The channels you want are:

• Mt Lofty transmitters (most of Adelaide): 6, 8, 11, 12, 33
• Grenfell Centre (city) transmitters (Adelaide Foothills): 54, 57, 61, 64, 66
• Kettering Rd transmitters (Elizabeth South), ABC and SBS only: 61 & 64

I'll take the example of someone in the northern suburbs of Adelaide who receives signals from both Mt Lofty and Kettering Rd transmitters.

They will get services from channels 6 (Seven), 8 (WIN), 11 (Ten), 12 (ABC), 33 (SBS), 61 (SBS) and 64 (ABC). This means that all the ABC and SBS services will be duplicated, but not the commercial services.

Removing duplicates

To remove duplicates in this case, check the Signal Strength/Quality for one service associated with each of channels 12, 33, 61 and 64. If the best signal scores are for ABC on 12 and SBS on 33, delete all services associated with channels 61 and 64. Don't forget the radio services! If the best signal scores are for ABC on 64 and SBS on 61, delete the services associated with channels 12 and 33.

Avoiding duplicates

Check the signal scores for one service associated with each of channels 12, 33, 61 and 64 as for Removing Duplicates and decide which channels you get the best ABC and SBS reception from.

In SETUP>System>Initialize, Clear Service Information.

If you want to receive ABC and SBS from Mt Lofty (channels 12 & 33), simply do a PARTIAL scan from Start Channel 6 to End Channel 33. This avoids scanning the Kettering Rd channels 61 and 64.

If you want to receive ABC and SBS from Kettering Rd, and the remaining channels from Mt Lofty, it's a bit more complicated. You need to do partial scans from channels 6 to 11, and then from 61 to 64, to avoid scanning channels 12 and 33, but including all the channels you want.

How do I find out what transmitters I can receive from?

The ABC's Tuning In Web page lets you look up the reception coverage of their transmitters. Just enter your suburb name or postcode to get a list of the ABC transmitters that might cover your location, and click on each of the ABC Digital links to see the coverage. Clicking on the coverage map will give you a larger view of the map. This will give you a hint to the coverage of the other broadcasters at the same site, but because of possible differences in the transmitter mast locations and the transmitter power, the ABC maps will potentially be less accurate for the other broadcasters. Unfortunately, as far as I know the ABC is the only broadcaster to provide this useful service.

The Australian Communications and Media Authority (ACMA) produces the Radio and Television Broadcasting Stations book. This is an authoritative listing of all licensed radio and television stations in Australia. Two of the most useful chapters are 8. Television by Channel Order and 9. Television by Area Served. The first is useful to help find where the transmitter is for a particular broadcast channel you are receiving, and the second can help find what transmitters are in your area. Digital TV transmitters are highlighted in light purple. The Contents and Explanatory notes helps interpret the data, and the General Information section has some information about channel frequencies and an outline of some of the broadcast standards.

Unfortunately, although chapter 9 lists the location of all transmitters' by latitude and longitude, that's a bit cumbersome if you want to find the nearest transmitters. The named area served can be useful, but the naming isn't always obvious.

The same Web page on the ACMA site also has a the transmitter data (more than what's in the book form) available as a Microsoft Excel spreadsheet (also readable using OpenOffice Calc) and a Microsoft Access database. Both of these forms are useful if you want to process the transmitter location data.

For the ACMA spreadsheet, there's a commandline tool, rtv2kml, that allows you convert CSV files written from the spreadsheet into Google Earth KML placemark files, so you can display the transmitter locations in Google Earth. When you click on the transmitter icons in Google Earth, you get a popup containing the basic information about the transmitter site and the transmitters there. rtv2kml runs on Windows, Linux, OS X and Cygwin. There are "pre-compiled" versions available for Windows, OS X and Cygwin. If you don't use the pre-compiled version, you need perl installed on your system. There are detailed installation notes in the README.txt in the distribution.

The Google Earth placemarks let you see at a glance where nearby transmitters are, what stations broadcast from the transmitter sites, and their frequencies, power, polarisation and whether the transmissions are directional. Unfortunately, there's no information about the main transmission directions for directional broadcasts. You can get some idea of the directions from the ABC coverage Web site mentioned above.

Thanks to tonymy01 for help with the section on problems caused by duplicate services and to sub3r for drawing my attention to the fact that the automatic handling of duplicate services doesn't always work.

Last update: 15 Oct 2014. Updated ACMA Radio and Television Broadcast Stations book link.

[prl]

The draft Scanning for Services FAQ is now open for comment. Do your worst

[tonymy01]

Failure of the EPG to display correctly, with services visible in live TV bissing EPG information. This can affect both Free-to-Air EPG and IceTV Guide.

Probably should be "missing" in that point .
Also, while deleting duplicates is a must, deleting ALL channels from the broadcaster you choose to delete just one of the duplicates from is a must. Else the EPG may still be empty for all services (despite not being duplicate any more). e.g
Say Seven Main has 7,70,72,73,74 and Seven Regional you are picking up has 7,70,72,73. Say the regional is better coverage for you, it is not good enough to simply delete 7,70,72,73 of the Main and leave 74 (as it is not duplicated at all). Once you decide to purge the duplicates on Seven Main, you need to purge ALL channels on Seven Main.

Ok, maybe there are no situations in the country like this example above, but I can imagine a real example of what might happen is someone deletes a duplicate accidentally from one broadcast frequency/location, and then as they are going through and deleting the rest of the duplicates (a day/week/whatever later) they might purge the rest from the other broadcast frequency/location, and thus still be receiving Seven from two locations in the Beyonwiz tuner tables, and thus will still end up with no EPG for possibly all of the broadcaster Seven channels (except the one).

Regards

[prl]

Failure of the EPG to display correctly, with services visible in live TV bissing EPG information. This can affect both Free-to-Air EPG and IceTV Guide.

Probably should be "missing" in that point .
Also, while deleting duplicates is a must, deleting ALL channels from the broadcaster you choose to delete just one of the duplicates from is a must. Else the EPG may still be empty for all services (despite not being duplicate any more). e.g
Say Seven Main has 7,70,72,73,74 and Seven Regional you are picking up has 7,70,72,73. Say the regional is better coverage for you, it is not good enough to simply delete 7,70,72,73 of the Main and leave 74 (as it is not duplicated at all). Once you decide to purge the duplicates on Seven Main, you need to purge ALL channels on Seven Main.

Ok, maybe there are no situations in the country like this example above, but I can imagine a real example of what might happen is someone deletes a duplicate accidentally from one broadcast frequency/location, and then as they are going through and deleting the rest of the duplicates (a day/week/whatever later) they might purge the rest from the other broadcast frequency/location, and thus still be receiving Seven from two locations in the Beyonwiz tuner tables, and thus will still end up with no EPG for possibly all of the broadcaster Seven channels (except the one).

Regards

I've fixed the typo. Thanks.

I thought that this covered what you were saying about deleting all duplicated:

Delete all the services associated with the channels you don't want to keep (YELLOW Delete button in LIST). Use the Radio/TV button to check radio services as well as TV services. Duplicated radio services need to be deleted, too.

I think it adequately covers your example.

[tonymy01]

I dunno, if there is just one channel not duplicated between 2 broadcasters, but all other PIDs effectively the same, then even though that channel doesn't have a duplicate, it has to be deleted if other services on that same frequency were chosen to be deleted.

[prl]

I dunno, if there is just one channel not duplicated between 2 broadcasters, but all other PIDs effectively the same, then even though that channel doesn't have a duplicate, it has to be deleted if other services on that same frequency were chosen to be deleted.

But I say to delete all services on the unwanted (broadcast) channel.

I've decided to add somewhere earlier that if two broadcast channels have any duplicated services, then only one of the two channels should have any services present.

I don't want to refer to deleting services in the general parts of the post, because thare are two different ways of dealing with the problem, and one of them (the one I think is the better in most circumstances) avoids getting duplicate services in the scan, so there's nothing to delete.

[tonymy01]

But I say to delete all services on the unwanted (broadcast) channel.

Ahh yes, that would do it

[prl]

But I say to delete all services on the unwanted (broadcast) channel.

Ahh yes, that would do it

Hi, Tony. I've added a paragraph at the end of the Dealing with duplicate services/Removing duplicates section re-emphasising that all services on unwanted channels have to be removed.

[sub3R]

Hi Peter. From my experience, your comment;

"UPDATE (Sep 2010):
The latest firmware versions now handle duplicate channels correctly as per The Free TV Australia Operational Practice OP-41 Logical Channel Descriptor" here, can be a bit misleading seeing this doesn?t always work correctly in some locations.

I think the word ?correctly? should be removed & possibly an amendment added to say that this may not always work correctly in some locations.

[prl]

Hi Peter. From my experience, your comment;

"UPDATE (Sep 2010):
The latest firmware versions now handle duplicate channels correctly as per The Free TV Australia Operational Practice OP-41 Logical Channel Descriptor" here, can be a bit misleading seeing this doesn?t always work correctly in some locations.

I think the word ?correctly? should be removed & possibly an amendment added to say that this may not always work correctly in some locations.

Agreed. How about:

UPDATE (Sep 2010):
The latest firmware versions (from 01.05.334 & 01.07.055) are intended to handle duplicate channels correctly as per The Free TV Australia Operational Practice OP-41 Logical Channel Descriptor. However, in some locations it selects the lower quality channels to use. In this case, clearing all services and using the appropriate partial scans (as in Dealing with duplicate services/Avoiding duplicates below) will force the use of the correct transmitter sites.

[sub3R]

Excellent.

[prl]

Excellent.

Fixed.

[SouthPark]

The draft Scanning for Services FAQ is now open for comment. Do your worst

Typo in 'transmiter' ..... in the line that says 'Choose the channel you want to keep from each set of duplicates. This will usually be the one with the best Signal Strength/Signal Quality, but if two channels have similar signal strength and quaility, then simply choose the one you prefer (e.g. possibly a metropolitan and regional transmiter for the same network; Seven vs Prime, for example). '

Inconsistency between 'favorites' and 'favourites'. Choose whether you want to use the american spelling 'initialize' - or the british style 'initialise'.

Typo in 'pre-complied'. Typo in 'Beyonwix'.

No big deal. I make typos all the time. Open for comment as mentioned, and I was doing my worst.

[prl]

Thanks. should be fixed now.

My spelling of Favorites/favourites in fact had a strange and deliberate consistency to it. "Favorites" (capitalised) referred to the Favorites list on the Beyonwiz, for which Beyonwiz engineering have decided (along with Initialize) to favour US rather than British spelling. I used "favourites" (not capitalised) to refer to favourites more generally - this was how I was taught to spell it Now all references have been changed to Favorites.

As for "Initialize", it is always used in the FAQ in the context of its position in the SETUP menu, and was spelt consistently that way throughout, since that is how it appears in the menus, even though I would normally not spell it that way.

[SouthPark]

No problem. Excellent draft Peter. And very nice efforts. Also, a very good point made about the 'favorites' list. Something that didn't occur to me until now. I will remember that! Thanks.

[Recusant]

Hiya, the URL for the "Radio and Television Broadcasting Stations book" needs to be updated. I found this: http://www.acma.gov.au/Industry/Broadca ... sters-acma

It's dated July 2014 but Canberra's stations just changed very recently. Does anyone know if it incorporates those changes?

I'll admit - i don't readily remember how to find the appropriate 'range' to avoid duplicates. The range used to be from channel 53 to 69. Can anyone save me the time if they've already worked it out?

Thanks

[prl]

Hiya, the URL for the "Radio and Television Broadcasting Stations book" needs to be updated. I found this: http://www.acma.gov.au/Industry/Broadca ... sters-acma

It's dated July 2014 but Canberra's stations just changed very recently. Does anyone know if it incorporates those changes?

I'll admit - i don't readily remember how to find the appropriate 'range' to avoid duplicates. The range used to be from channel 53 to 69. Can anyone save me the time if they've already worked it out?

Thanks

I'll update the link in the FAQ. Thanks for the reminder.

The most recent version of the ACMA Radio and Television Broadcasting Stations data is in the spreadsheets on that page. The October data has both the old and new frequencies for the Canberra transmitters that are retuning in October (Weston Creek/Woden & Tuggeranong), but doesn't distinguish them. You can get the full retune timetable from the Department of Communications restack page, and that, combined with the ACMA data, allows you to find the new frequencies.

To save you the bother, the correct range for tuning from Tuggeranong or Weston Creek/Woden is now 41-45 (Weston Creek/Woden is only 41, ABC and 45, SBS). That will exclude the old frequencies during the simulcast (which should now have finished) and the Black Mountain transmitters.

I don't know why the text version of the Radio and Television Broadcasting Stations book has been allowed to fall so far behind the data files on the same page.

[Recusant]

Thank you so much prl. Always so helpful

[prl]

No problem.