<?xml version="1.0" encoding="utf-8" standalone="yes"?><html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Three-layer network</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:dn02228404:4:en:global:publishing_online_1_0:data:data:*:*:*" date="2005-02-28T15:43:19Z"?>
<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:dn02228404:4:en:global:publishing_online_1_0:data:data:4:*:*" date="2005-02-28T15:43:19Z"?>
</head>
<body lang="en" xml:lang="en">
<p><a name="nov22216452522" shape="rect"></a>
<a name="ned_8" shape="rect"></a></p>

<div class="div">
<div class="div">
<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%"><a href="NED?action=retrieve&amp;identifier=dn02228404&amp;edition=4&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=ned_6#ned_6" onclick="sync(this);return true" shape="rect">Traffic management between network layers</a></td>
<td align="center" colspan="1" rowspan="1" width="20%"><a href="NED?action=retrieve&amp;identifier=dn02228404_about&amp;edition=4&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=dn02228404_about&amp;edition=4&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">
<h3>Three-layer network</h3>

<p>A three-layer network contains two macro layers, 900/800
and 1800/1900, and one micro layer, 900/800 or 1800/1900.</p>


<p>The traffic management strategy must be chosen to push
the dual band MS towards the layers which offer more capacity and have better
quality. Normally, this kind of layers are the 1800/1900 layer and the micro
layer. The 900/800 macro layer is seen as a collector layer where the calls
are set up. When the calls are processed, they are routed by following the
chosen strategy (the selection of the “right layer” can also be done during
the idle mode by using the C2 parameter). </p>


<p>Basically, there are two reasonable ways: the highest priority
is given to the 1800/1900 layer or the 900/800 π-layer.</p>


<a name="nov22216462223" shape="rect"></a>
<div class="topic">
<h4>Priority
to Micro Cell Layer</h4>

<p>The figure <em>Three-layer network strategy
No.1, priority to micro cell layer </em>shows the general idea of this strategy:</p>


<a name="dec22185484" shape="rect"></a>
<div>
<img alt="urn:mars:dn02250409:1:en:global:cgm_fixed:data:data" border="0" src="NED?action=retrieve&amp;identifier=dn02250409&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=gif&amp;component=data&amp;item=data" /><p class="figure-caption">Figure: Three-layer network strategy No. 1, priority to micro cell layer </p>
</div>


<p>The 1800/1900 and 900/800 macro layers are defined as the
same-level layers and the micro cellular layer is defined as the lower layer
from the 1800/1900 and 900/800 macro by using the <span class="parameter-sem">Adjacent
Cell Layer</span> parameter.</p>


<p>The dual band mobiles are sent to the 1800/1900 layer with
a Power Budget handover with a negative margin, that is, the capture is done
very quickly (the default value for the measurement window is 6 SACCH frames,
which means approximately 6 seconds) - similar to an umbrella handover. The
recommended value for the margin is -24 dB and the recommended RxLevMin (the
minimum level value to access the cell during a handover) is -90 dB (in the
1800 cell). The negative power budget handover is used here, because the umbrella
handover cannot be used together with the Fast Moving Mobile algorithm.</p>


<p>The micro cellular layer can be used for slow mobiles only.
The capture is done using the Fast Moving Mobile algorithm from the 900/800
macro and from the 1800/1900 cells. The recommended value for <span class="parameter-sem">Fast
Moving Threshold</span> is 32 SACCH frames, and the <span class="parameter-sem">Adjacent
Umbrella Cell Level</span> is set to -85 dB. The same parameters are used in
the 1800/1900 and 900/800 source cells. This ensures that all slow moving
dual band mobiles go down to the micro cellular layer.</p>


<p>The figure <em>Strategy No. 1, priority
to micro cell layer, main parameter values</em> summarises the main parameter
values.</p>


<a name="dec2218725" shape="rect"></a>
<div>
<img alt="urn:mars:dn02250412:1:en:global:cgm_fixed:data:data" border="0" src="NED?action=retrieve&amp;identifier=dn02250412&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=gif&amp;component=data&amp;item=data" /><p class="figure-caption">Figure: Strategy No. 1, priority to micro cell layer, main parameter values </p>
</div>


<p>Within a layer, 900/800 macro, 1800/1900 macro or micro,
the mobiles use Power Budget algorithms with a positive margin (+ 6 dB) to
stay on the best cell. The mobiles are going from one layer to another using
radio-reason handover algorithms (level or quality handovers).</p>


<p>If the 1800/1900 layer coverage is not seamless, special
parameterisation is used at the border areas. The power budget margin is set
at + 12 dB instead of + 63 dB to allow the mobiles to go back to the 900/800
layer before the level or the quality becomes poor. This is shown in the figure <em>Parameter change at coverage border</em>. This could also be
applied to the micro cellular layer.</p>


<a name="dec22188296" shape="rect"></a>
<div>
<img alt="urn:mars:dn02250436:1:en:global:cgm_fixed:data:data" border="0" src="NED?action=retrieve&amp;identifier=dn02250436&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=gif&amp;component=data&amp;item=data" /><p class="figure-caption">Figure: Parameter change at coverage border </p>
</div>


<p>The same strategy can be achieved by using the umbrella
handover instead of the negative power budget from macro 900/800 to macro
1800/1900.</p>


<p>The 1800/1900 is defined as a LOWER layer from the 900/800
macro layer and the micro cellular layer is defined as a LOWER layer from
the 1800/1900 and 900/800 macro by using <span class="parameter-sem">Adjacent Cell
Layer</span> parameter.</p>


<p>The dual band mobiles are sent to the 1800/1900 layer with
an S5 MS speed algorithm with the <span class="parameter-sem">Fast Moving Threshold</span>
set to 1 SACCH, which means that the capture is done nearly instantly. The
recommended value for <span class="parameter-sem">Rx Lev Min</span> (the minimum
level value to access the cell during a handover) is -85 dB (in the 1800/1900
cell).</p>


<p>The micro cellular layer must be used for slow mobiles
so the capture is done by using the Fast Moving mobile algorithm from the
900/800 macro and from the 1800/1900 cells. The recommended value for the <span class="parameter-sem">Fast Moving Threshold</span> is 32 SACCH frames and the <span class="parameter-sem">Adjacent Umbrella Cell Level</span> is set to -85 dB. The
same parameters are used in the 1800/1900 and 900/800 source cells. This ensures
that all slow moving dual band mobiles go down to the micro cellular layer.</p>
</div>


<a name="nov2221650624" shape="rect"></a>
<div class="topic">
<h4>Priority
to 1800/1900 Layer</h4>

<a name="dec221810288" shape="rect"></a>
<div>
<img alt="urn:mars:dn02250463:1:en:global:cgm_fixed:data:data" border="0" src="NED?action=retrieve&amp;identifier=dn02250463&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=gif&amp;component=data&amp;item=data" /><p class="figure-caption">Figure: Three-layer network strategy No. 2, priority to 1800 layer </p>
</div>


<p>The 1800/1900 and 900/800 macro layers are defined as the
same-level layers and the micro cellular layer is defined as a lower-level
layer from 1800/1900 and 900/800 macro by using the <span class="parameter-sem">Adjacent
Cell Layer</span> parameter.</p>


<p>The dual band mobiles are sent to the 1800/1900 layer with
a power budget handover with a negative margin, that is, the capture is done
very quickly (the default value for the measurement window is 6 SACCH frames,
or approximately 6 seconds) - the same as an umbrella handover. The recommended
value for this margin is -24 dB, <span class="parameter-sem">Rx Lev Min</span> (the
minimum level value to access the cell during a handover) is -85 dB (in the
1800 cell).</p>


<p>The micro cellular layer must be used for slow mobiles,
so the capture is done by using the Fast Moving mobile algorithm from the
900/800 macro. The recommended value for the <span class="parameter-sem">Fast Moving
Threshold</span> is 32 SACCH frames and the <span class="parameter-sem">Adjacent
Umbrella Cell Level</span> is set to -85 dB. </p>


<p>In this case, dual band MSs must be routed to the 1800/1900
layer, even if they are analysed as slow moving mobiles. In that order, the
1800/1900 layer is defined as a lower layer from the micro layer, and the
umbrella handover is enabled with a HO period of 6 SACCH. This parameterisation
ensures a fast capture of the dual band MS in the 1800/1900 layer. Another
possibility would be to define the <span class="parameter-sem">Fast Moving Threshold</span>
to equal 0 and to also disable the speed measurements. This should be studied
as a Change Note. </p>


<p>Within a layer, 900/800 macro, 1800/1900, or micro, the
mobiles use Power Budget algorithms with a positive margin (+ 6 dB) to stay
on the best cell.</p>


<p>The figure <em>Strategy No. 2, main parameter
values</em> summarises the main parameters used:</p>


<a name="dec221811509" shape="rect"></a>
<div>
<img alt="urn:mars:dn02250487:1:en:global:cgm_fixed:data:data" border="0" src="NED?action=retrieve&amp;identifier=dn02250487&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=gif&amp;component=data&amp;item=data" /><p class="figure-caption">Figure: Strategy No. 2, main parameter values </p>
</div>
</div>
</div>
</div>
</div>
</body>
</html>