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<concept id="GUID-F5FE22F3-B7C4-50B3-9B36-5CB8BC1BA18A" xml:lang="en"><title>Receiving

Broadcast Data</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>This topic gives information about how to receive the broadcast data. </p>

<section><title>Purpose</title> <p>This tutorial is about creating IP filters,

removing the IP filters and updating the network time. </p> <p><b>Required

Background</b> </p> <p>IP platform contains many services, so each service

is an IP data stream identified by the IP address. </p> </section>

<section><title>Introduction</title><p>For a DVB-H application, you have to

receive a small number of services. So you need to filter out from a large

number of IP data packets for a small number of services. This is done by

asking the receiver to only send IP packets matching a specific IP address,

or a small number of IP addresses. This is called filtering. </p> <p>The receiver

has the ability to filter network time from a DVB-H broadcast, for you to

get network updated time. </p></section>

<section><title>Setup and Configuration Requirements</title><p>The initial

step to create a filter is to obtain the IP address of desired services. Further

setup is beyond the scope of this document, but some typical steps are: </p> <ul>

<li id="GUID-BE351C29-0BE5-5B37-A87C-945603B13A10"><p>You can setup a well-known

IP address of bootstrap ESG service for an IP platform. </p> </li>

<li id="GUID-2C054EA0-911E-5764-8804-9BF020297317"><p>You can obtain from

the bootstrap, the ESG IP address of a particular ESG service for an IP platform </p> </li>

<li id="GUID-24AFC3F8-C6AF-5857-915A-1CE942532D76"><p>You can obtain an ESG

service from the IP address of a TV programme. </p> </li>

</ul></section>

<section><title>Using Receiving Broadcast Data Tutorial </title> <p>The Following

tasks will be covered in this tutorial: </p> <ul>

<li id="GUID-8038AAAC-85FD-52E3-B2FF-0C3F118222DD"><p><xref href="GUID-5808DC87-C55B-4488-9099-B0F9BB167BDA.dita">Creating

IP Filters</xref></p> </li>

<li id="GUID-C20A0F85-75A8-5A78-ABFE-BFE0183C8756"><p><xref href="GUID-7D83F734-4298-44C9-BBA1-DC2F9E1E32E2.dita">Updating

Network Time</xref> </p> </li>

</ul> </section>

<section><title>Example</title><codeblock id="GUID-710BFB6A-19CA-524C-8DFE-610D430ED284" xml:space="preserve">

//Context: The following takes place in some method of an active object

//that implements MDvbhDataObserver (e.g. CExampleClient : public

//CActive, public MDvbhDataObserver).  Its member iReceiver is a 

//RDvbhReceiver that has previously been initialised.  Its member iAddress

//contains the IP address to filter.

//Assume that CExampleClient previously registered itself as a

//MDvbhDataObserver as in Figure 8.

TInt filterId = 0;

User::LeaveIfError(iReceiver.CreateFilter(iAddress, 

                                          filterId, 

                                          iStatus));

StoreFilterIdL(filterId , iAddress);

SetActive();

//Filter now active. For as long as it remains active, any IP data the

//receiver gets that matches the IP address will be sent to the client.

//....At some later stage, perhaps within another function:

User::LeaveIfError(iReceiver.CancelFilter(filterId));

//Filter removal initiated.  When complete, CExampleFilter::RunL will be

//called and related IP data will no longer be filtered.

//Example CExampleFilter::RunL()

void CExampleFilter::RunL()

    {

    //CreateFilter() operation has completed, which means the filter no

      //longer exists.  Check iStatus for completion code (KErrCancelled,

      //KErrNotReady, etc.) and act accordingly.  For example:

    RemoveFilterIdFromStorage(iAddress);

    }

</codeblock></section>

<section><title> Removing IP Filters</title> <p>In order to remove an active

IP filter on the receiver, call <xref href="GUID-617CD367-CF68-3932-8E77-669820A7B9AF.dita#GUID-617CD367-CF68-3932-8E77-669820A7B9AF/GUID-42D70FDD-9206-33B3-B5ED-3A04B5F03036"><apiname>RDvbhReceiver::CancelFilter()</apiname></xref>.

The instance is passed through filter ID. If it represents an active filter,

then the filter is removed and its corresponding asynchronous request is completed

with error reason as KErrCancelled. According to it, IP packets for that filter

will no longer be sent to the client. </p> <p>If the filterId does not represent

an active filter, an error will be returned. As long as there exists at least

one active filter on the receiver, it will be in a receiving state. When the

last active filter has been removed, the receiver will move to ready state. </p> </section>

</conbody><related-links>

<link href="GUID-3C9BE2FF-8D5C-51D0-8BC1-BED7BC1288BA.dita"><linktext>Turn On Broadcast

Receiver</linktext></link>

<link href="GUID-2C8BE998-BCCE-5A06-AFC1-4B611D9233AB.dita"><linktext>Turn Off

Broadcast Receiver</linktext></link>

<link href="GUID-0297CAF5-4EB7-5E84-8A8C-8758D6F3B75F.dita"><linktext>Setting Data

Reception</linktext></link>

<link href="GUID-567585CC-26EC-553D-99D5-D3C178C455F6.dita"><linktext>DVB-H Signal

Scanning</linktext></link>

<link href="GUID-743D3117-095B-58D5-947D-A8713475C9A5.dita"><linktext>Tuning IP

Platform</linktext></link>

</related-links></concept>