<?xml version="1.0" encoding="utf-8" standalone="yes"?><html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Overview of Support for PBCCH/PCCCH</title>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<meta content="text/css" http-equiv="Content-Style-Type" />
<script src="NED?action=retrieve&amp;identifier=dn00188761&amp;edition=1&amp;language=none&amp;coverage=global&amp;encoding=javascript&amp;component=data&amp;item=data" type="text/javascript" xml:space="preserve">
</script>
<?conversion name="Pub2XHTML" version="2.0" source="urn:mars:dn0433398:2:en:global:publishing_online_1_0:data:data:*:*:*" date="2005-02-28T16:03:20Z"?>
<link href="NED?action=retrieve&amp;identifier=dn01158124&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=css&amp;component=data&amp;item=data" rel="stylesheet" title="Nokia Networks default online style" type="text/css" />
<meta content="draft" name="status" />
<?conversion name="SplitHTML" version="1.9" source="urn:mars:dn0433398:2:en:global:publishing_online_1_0:data:data:73:*:*" date="2005-02-28T16:03:20Z"?>
</head>
<body lang="en" xml:lang="en">
<p><a name="ned_top" shape="rect"></a>
<a name="ned_1" shape="rect"></a></p>

<a name="p2xhtm-repid-1" shape="rect"></a>
<table width="100%">
<tr>
<td align="center" colspan="1" rowspan="1" width="20%"><?NED5 annotation?>
<br clear="none" /><?NED5 printview?>
</td>
<td align="center" colspan="1" rowspan="1" width="20%"></td>
<td align="center" colspan="1" rowspan="1" width="20%"></td>
<td align="center" colspan="1" rowspan="1" width="20%"></td>
<td align="center" colspan="1" rowspan="1" width="20%"><a href="NED?action=retrieve&amp;identifier=dn0433398_about&amp;edition=2&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=ned_top#ned_top" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=dn0433398_about&amp;edition=2&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=ned_top#ned_top');return false" shape="rect" target="_blank"><img alt="Document information" border="0" class="Metainfo" src="NED?action=retrieve&amp;identifier=dn01158003&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=gif&amp;component=data&amp;item=data" /></a></td>
</tr>
</table>


<div class="div">
<h1>Overview of Support for PBCCH/PCCCH</h1>

<p>Support of PBCCH/PCCCH brings a dedicated common control
channel (CCCH) capacity for (E)GPRS services.</p>


<p>The PBCCH/PCCCH channels use the same timeslot. PBCCH/PCCCH
should be configured on the same TRX as the broadcast control channel (BCCH)
in the case of a multi-band cell. With the current implementation, the PBCCH/PCCCH
cannot carry user data.</p>


<p>Nokia implementation is based on the Network Mode of Operation I (NOM
I). The operator should not create the PBCCH/PCCCH channel in NOM II because
it does not support circuit switched paging on PCCCH.</p>


<a name="oct1141440561" shape="rect"></a>
<div class="topic">
<h2>Packet common control channel (PCCCH)</h2>

<p>The packet common control channel (PCCCH) comprises logical
channels for packet common control signalling. The following common control
channels are available:</p>


<ul>
<li><p>packet random access channel (PRACH)</p>
</li>
<li><p>packet access grant channel (PAGCH)</p>
</li>
<li><p>packet notification channel (PNCH)</p>
</li>
<li><p>packet paging channel (PPCH)</p>
</li>
</ul>


<p>The MS uses PRACH to initiate an uplink transfer to send
data or signalling information. Packet Access burst and Extended Packet Access
burst are used on the PRACH.</p>


<p>The PAGCH is used in the packet transfer establishment
phase to send resource assignment to an MS prior to packet transfer.</p>


<p>The PPCH is used to page an MS prior to a downlink packet
transfer for the packet data services and to page circuit switched services.
The PPCH uses paging groups in order to allow the usage of DRX mode. The paging
for circuit switched services on the PPCH requires a Gs interface between
the MSC and SGSN.</p>


<p>The network sends a CS paging message for a GPRS-attached
MS either on the same channel as the GPRS paging channel (that is, the PPCH
or the CCCH paging channel), or on a GPRS traffic channel. This means that
the MS needs only to monitor one paging channel and that it receives CS paging
messages on the packet data channel when it has been assigned a packet data
channel.</p>
</div>


<a name="oct1141454342" shape="rect"></a>
<div class="topic">
<h2>Packet Broadcast Control Channel (PBCCH)</h2>

<p>The Packet Broadcast Control Channel (PBCCH) is used to
broadcast packet data specific System Information messages (for example C31
and C32 cell selection criteria).</p>


<p>The cell re-selection criteria C31 and C32 are provided
as a complement to the current GSM cell re-selection criteria. C31/C32 provide
a more general tool, which makes cell planning for GPRS similar to the existing
planning in the GSM.</p>


<p>C31 is a signal strength criterion used to decide whether prioritised
cell re-selection shall be used. For cells that fulfil the C31 criterion,
the cell with the highest priority class shall be selected. If more than one
cell has the highest priority, the one of those with the highest C32 value
shall be selected. If no cell fulfils the C31 criterion, the one among all
cells with the highest C32 value shall be selected.</p>


<p>If the PBCCH is not allocated, the packet data specific
system information is broadcast on the BCCH, and the existing C1/C2 are used. </p>


<p>See <em>Cell selection and re-selection</em> for more
information on the cell re-selection criteria.</p>
</div>
</div>
</body>
</html>