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<td align="center" colspan="1" rowspan="1" width="20%"><?NED5 annotation?>
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<div class="div">
<h2>Interworking with other features</h2>

<a name="jan2651511585" shape="rect"></a>
<div class="topic">
<h3>Configuration with Common BCCH</h3>

<p>The band where the BCCH carrier resides in the common BCCH controlled
segments must be the same throughout the whole network.</p>


<p>BCCH is allowed in the EGSM 900 frequency band only if there is no PGSM
900 frequency band in use in the network.</p>
</div>


<a name="jan2651514226" shape="rect"></a>
<div class="topic">
<h3>BCCH allocation</h3>

<p>In Common BCCH, the BCCH frequency of the segment is added
among the BCCH frequencies that the MS should measure when the MS is active
on the non-BCCH band of the segment. This leads to the following restrictions:</p>


<ul>
<li><p>There can be only 31 frequencies on
adjacent cell frequency list and BCCH Allocation frequency list.</p>
</li>
<li><p>Only 5 of the strongest neighbours
are included in the adjacent cell measurements.</p>
</li>
</ul>
</div>


<a name="jan2651514377" shape="rect"></a>
<div class="topic">
<h3>SDCCH allocation</h3>

<p>In a multi-band Common BCCH, the Initial SDCCH channel
for a call set-up is always allocated in the frequency band where also the
segment's BCCH is located. </p>


<p>When an SDCCH is allocated for an external handover in
a multi-band Common BCCH segment, the search may be restricted among the BCCH
frequency band resources of the segment. This depends on the frequency band
the BCCH is using. If the non-BCCH layer is regarded as a layer with less
coverage (as indicated by the positive value of the <span class="parameter-sem">Non
BCCH Layer Offset</span> parameter), only BCCH frequency band resources are
used in SDCCH allocation for external handovers.</p>
</div>


<a name="jan2651517329" shape="rect"></a>
<div class="topic">
<h3>Dynamic SDCCH allocation</h3>

<p>The dynamic SDCCH <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04980#id04980" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04980#id04980');return false" shape="rect" target="_blank">RTSLs</a> can be
utilised only in the BCCH frequency band in a Common BCCH cell. This is due
to the fact that the multi-band capabilities of an accessing MS are not known
at the time of the initial SDCCH allocation.</p>
</div>


<a name="nov2621243485" shape="rect"></a>
<div class="topic">
<h3>Queuing</h3>

<p><a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05018#id05018" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05018#id05018');return false" shape="rect" target="_blank">Queuing</a> is applied at the segment level.
There is no priority between different mobile types; therefore the mobiles
supporting all frequency bands are more likely to be allocated a channel.</p>


<p>There is no specific reason to vary the values of the parameters <span class="parameter-sem">Time Limit Call</span> and <span class="parameter-sem">Time Limit
Handover</span> with respect to the one-layer network setting.</p>


<p>The value of the parameter <span class="parameter-sem">Max Queue
Length</span> has to be re-setting, considering that the percentage is evaluated
on the total number of <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04885#id04885" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04885#id04885');return false" shape="rect" target="_blank">TRXs</a> (including all <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id03816#id03816" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id03816#id03816');return false" shape="rect" target="_blank">BTSs</a>
of the segment) and the resulting number should be lower than the number of
available <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id011274#id011274" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id011274#id011274');return false" shape="rect" target="_blank">SDCCH</a> channels on the <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04445#id04445" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04445#id04445');return false" shape="rect" target="_blank">BCCH</a>
serving layer band. This is because some capacity must be left to services
that run on SDCCH only (for example, <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05515#id05515" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05515#id05515');return false" shape="rect" target="_blank">SMS</a>).</p>


<p>Some mobiles may be put into a queue even though all the <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04070#id04070" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04070#id04070');return false" shape="rect" target="_blank">TCH</a> resources of the segment are not fully utilised
(this is the case when the mobile in the queue does not support the available
capacity). In this case it is very important to make sure that SDCCH capacity
is still available for further requests from mobiles supporting the available
TCH capacity. For this reason the margin between <span class="parameter-sem">Max
Queue Length</span> and the number of SDCCH channels on the BCCH serving layer
band should be greater than before.</p>
</div>


<a name="dec3131542191" shape="rect"></a>
<div class="topic">
<h3>(E)GPRS</h3>

<p>Each BTS object in a segment has its own GPRS terrritory.
The parameters that are used to define the size of GPRS territory are adjusted
in each BTS.</p>


<p>When comparing the TCH load of a segment's BTS with the
parameter <span class="parameter-sem">BTS Load In SEG</span>, the BSC interpretes
RTSLs in GPRS territory as busy channels (excluding dedicated GPRS resources).
This interpretation prevents the GPRS territory of a single BTS from shrinking
unnecessarily, if there are other BTSs in the segment to which CS calls could
be transferred from the BTS in question.</p>


<p>Every GPRS BTS in a segment has to be connected to the
same PCU.</p>


<p>For more information about GPRS territories, see <em>(E)GPRS in BSC</em> in BSC/TCSM documentation.</p>
</div>


<a name="nov2621245116" shape="rect"></a>
<div class="topic">
<h3>Pre-emption</h3>

<p>When the segment architecture is used, <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id013186#id013186" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id013186#id013186');return false" shape="rect" target="_blank">Pre-emption</a>
is a segment level function.</p>


<p>In a segment with several BTSs of different properties it is possible
that a TCH request cannot be served even though all the TCH resources in a
segment are not fully utilised. However, pre-emption is possible if permitted
by the related parameters.</p>


<p>The candidate for the forced actions is selected among the resource
types that are indicated as reasonable in the resource request that initiates
these actions. In the candidate selection the criterion of the lowest possible
priority is the most important one. When searching for the lowest priority
call the different resource types are preferred so that the BTSs that use
same frequency band as BCCH-BTS are the most preferred ones.</p>
</div>


<a name="nov262124617" shape="rect"></a>
<div class="topic">
<h3>Intelligent
Underlay-Overlay</h3>

<p>In the segment environment, the use of <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id09027#id09027" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id09027#id09027');return false" shape="rect" target="_blank">Intelligent
Underlay-Overlay</a> is a BTS-specific functionality. Each BTS in a segment
can have its own regular and super-reuse layers. The super-reuse layer of
a BTS can be accessed only via the regular layer of the BTS.</p>


<a name="dec121934157" shape="rect"></a>
<div>
<img alt="urn:mars:dn02249988:1:en:global:cgm_fixed:data:data" border="0" src="NED?action=retrieve&amp;identifier=dn02249988&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=gif&amp;component=data&amp;item=data" /><p class="figure-caption">Figure: IUO frequency groups in GSM 900 / GSM 1800 Common BCCH network</p>
</div>


<a name="dec12193658" shape="rect"></a>
<div>
<img alt="urn:mars:dn02249991:1:en:global:cgm_fixed:data:data" border="0" src="NED?action=retrieve&amp;identifier=dn02249991&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=gif&amp;component=data&amp;item=data" /><p class="figure-caption">Figure: IUO frequency groups in GSM 800 / GSM 1900 Common BCCH network</p>
</div>


<p>The target for a super-reuse TCH request is always one
BTS (a few TRXs within the BTS) and not the whole segment as in resource requests
in general. The <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id03626#id03626" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id03626#id03626');return false" shape="rect" target="_blank">handover</a> from regular resources to
super-reuse resources in a BTS is the same regardless of whether segment architecture
is used or not.</p>


<p>When an IUO handover from a super-reuse TRX to the regular
resources of a BTS is performed, the information on the usability of different
resource types in the segment is decided based on the values of the parameter <span class="parameter-sem">Non BCCH Layer Offset</span> in the different BTSs of the
segment. As a target, the <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04439#id04439" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04439#id04439');return false" shape="rect" target="_blank">BSC</a> accepts the BTSs whose <span class="parameter-sem">Non
BCCH Layer Offset</span> value is less than or equal to the value of the BTS
where the handover was initiated. This is indicated in the figure <em>Possible
handover directions on a segment</em> with dashed-line arrows going from
the super-reuse layer of one BTS to the regular layer of another BTS in a
segment.</p>


<p>The <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id09035#id09035" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id09035#id09035');return false" shape="rect" target="_blank">child cell</a> concept is not supported
in the BSC in which the segment option is enabled. </p>


<p>Direct Access to super re-use layer is only supported inside
the BTS_Object with the initial SDCCH, which must be in the BCCH band.</p>


<p>To get an accurate estimation of the C/I value of the Common
BCCH segment's non-BCCH frequency band layer, the estimation is based on the
measurement of the BCCH frequency in the segment. The C/I calculation is modified
so that the segment's BCCH measurement result is used instead of the serving
TCH measurement result.</p>


<a name="dec1219393911" shape="rect"></a>
<div>
<img alt="urn:mars:dn02250003:1:en:global:cgm_fixed:data:data" border="0" src="NED?action=retrieve&amp;identifier=dn02250003&amp;edition=1&amp;language=en&amp;coverage=global&amp;encoding=gif&amp;component=data&amp;item=data" /><p class="figure-caption">Figure: Possible handover directions on a segment</p>
</div>
</div>


<a name="nov26212505411" shape="rect"></a>
<div class="topic">
<h3>Multi
BCF</h3>

<p>When Common BCCH is combined with Multi <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04982#id04982" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id04982#id04982');return false" shape="rect" target="_blank">BCF</a>,
you are allowed to configure to one segment both BTSs of different frequency
bands and BTSs of different base station types.</p>


<p>For more information, see <a href="NED?action=retrieve&amp;identifier=dn03514617&amp;edition=2&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=dec331634541#dec331634541" onclick="sync(this);return true" shape="rect">Overview of implementing Multi BCF</a>.</p>
</div>


<a name="nov26212512612" shape="rect"></a>
<div class="topic">
<h3>Frequency
Hopping</h3>

<p>The multiband MS and the multiband network support <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05054#id05054" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05054#id05054');return false" shape="rect" target="_blank">Frequency
Hopping</a> within each band of operation. Frequency Hopping between the
bands of operation is not supported. Frequency Hopping is managed by a BTS
when the segment concept is in use.</p>


<p>In the selected segment architecture the resources of different types
are grouped as separate BTSs. All the resource types have the hopping parameters
and the hopping groups of their own.</p>


<p>The segment architecture enables having BTSs without a BCCH TRX. This
reduces the amount of hopping groups in the regular area of a BTS, because
there is no need for a separate group for the BCCH TRX in RF hopping. In BB
hopping there is also no need for separating TSL0 from the other TSLs in BTSs
that do not contain a BCCH TRX. However, the separation between TSL0 and other
TSLs remain and these are regarded as two different hopping groups. The user
gives one set of parameters for the TSL0 group and another for the other TSLs.
A similar set of parameters can be given for both.</p>


<p>The segment model offers the opportunity to have several hopping groups
even though there are only resources for one band in a segment. The operator
can form hopping groups by gathering the needed TRXs into one BTS and have
several BTSs of the same band. Each BTS has the hopping parameters of its
own.</p>
</div>


<a name="nov26212542013" shape="rect"></a>
<div class="topic">
<h3>Intelligent
Coverage Enhancement</h3>

<p><a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id09017#id09017" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id09017#id09017');return false" shape="rect" target="_blank">Intelligent Coverage Enhancement</a> can
be used in the BCCH BTS of common BCCH controlled cells.</p>
</div>


<a name="nov26212553914" shape="rect"></a>
<div class="topic">
<h3>Extended
Cell</h3>

<p>In a segment environment, only BCCH BTSs can have extended
area TRXs.</p>
</div>


<a name="nov26212563315" shape="rect"></a>
<div class="topic">
<h3>Directed
Retry</h3>

<p><a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id08638#id08638" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id08638#id08638');return false" shape="rect" target="_blank">Directed Retry</a> or Intelligent Directed
Retry can be triggered even if all resources of a segment are not completely
in use. Since the Directed Retry procedure reduces SDCCH capacity, the Directed
Retry timers should not be set too high and SDCCH capacity should be dimensioned
with the proper margin, to avoid SDCCH blocking (due to the DR procedure)
for any mobile supporting the available TCH capacity.</p>
</div>


<a name="nov2621257616" shape="rect"></a>
<div class="topic">
<h3>Direct
Access to Desired Layer/Band</h3>

<p>The purpose of <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id011216#id011216" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id011216#id011216');return false" shape="rect" target="_blank">Direct Access to
Desired Layer/Band</a> is to direct traffic in the call setup phase from
the SDCCH of a <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05249#id05249" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05249#id05249');return false" shape="rect" target="_blank">macro cell</a>/GSM 900/800 cell to a TCH
of a <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id08868#id08868" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id08868#id08868');return false" shape="rect" target="_blank">micro cell</a>/GSM 1800/1900 cell whenever possible. </p>


<p>In the segment environment, DADL/B can be used to direct
traffic between segments. The loads are evaluated per segment, adjacency definitions
are between segments, and DADL/B handovers are made between segments.</p>
</div>


<a name="nov2621258317" shape="rect"></a>
<div class="topic">
<h3>Advanced
Multilayer Handling</h3>

<p>The BSC-controlled traffic-reason handover is a segment
level procedure, including the related parameters. The loads are evaluated
per segment, and the idea is that the power budget margin is dynamically changed
to direct the MSs hanging around on the segment border to less loaded adjacent
segments. </p>


<p>Nevertheless, if each segment is dimensioned to handle
the needed capacity (as it should be with Common BCCH, considering that 3
different bands can be used and up to 36 TRX objects are allowed in a segment),
the traffic should be smoothed out among the BTSs within a segment, rather
than directed to adjacent segments. Therefore, when Common BCCH is active
and the segments are multi-band, the Advanced Multilayer Handling is less
beneficial.</p>
</div>


<a name="nov26212585718" shape="rect"></a>
<div class="topic">
<h3>Dynamic
Hot Spot</h3>

<p>The Dynamic Hot Spot control operates mainly on the BTS
level. The usability of a given frequency band is defined by examining the
interference of the respective band in the neighbouring cells. Here PGSM 900
and EGSM 900 are regarded as one GSM 900 band and the examinations are made
accordingly. The dynamic hot spot algorithm is applied when the number of
busy <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05#id05" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id05#id05');return false" shape="rect" target="_blank">TSLs</a> in the layer where TCH is requested exceeds
the threshold parameter <span class="parameter-sem">Soft Blocking Start Reg</span>. </p>


<p>Since adjacencies are defined on the segment level, the
interfered cells are also defined at the segment level: all the possible BTSs
of an adjacent segment are examined (layer by layer) if the segment has been
defined as an interfered cell. Frequency-hopping groups must be allocated
using the same criteria for all frequency bands. This means that all the layers
of a given segment are interfered by the corresponding layers of the interfering
segment. In the soft blocking evaluation, the contributions from BTSs belonging
to the same band are summed up and if different frequency groups are assigned
to BTSs belonging to the same band and same segment, frequency groups should
be assigned in all the interfered segments.</p>


<p>A non-uniform network where one-band segments exist together
with multi-band segments does not affect the performance of Dynamic Hot Spot.</p>


<p>Dynamic Hot Spot is applied in call attempts and incoming
inter-BTSs handovers (external, internal inter and intra segment), except
when TCH is allocated inside a non-hopping TRX or an internal inter-segment
handover is performed because of bad signal quality.</p>
</div>


<a name="nov262131119" shape="rect"></a>
<div class="topic">
<h3>Minimum
acceptable C/N ratio in channel allocation</h3>

<p>If the value of the parameter <span class="parameter-sem">CN
Threshold</span> varies between the BTSs of the same resource type, the BSC
selects the highest value for calculation. The recommendation for a certain
resource type in the segment is disabled when the value is not used even in
one of the BTSs of the same resource type.</p>
</div>


<a name="nov2621314520" shape="rect"></a>
<div class="topic">
<h3>MS
power level optimisation in handover and call setup</h3>

<p>If the value of the parameter <span class="parameter-sem">Optimum
Rx Lev UL</span> varies between the TRXs of the BTSs of the same resource type,
the BSC selects the highest value for calculation. The optimum uplink RF signal
level for a certain resource type in the segment is disabled when the value
is not used even in one of the TRXs of the BTSs of the same resource type. </p>
</div>


<a name="nov262133121" shape="rect"></a>
<div class="topic">
<h3>FACCH
Call Setup</h3>

<p><a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id011221#id011221" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id011221#id011221');return false" shape="rect" target="_blank">FACCH</a> Call Setup means allocating a
TCH for the signalling phase of a call in a SDCCH congestion. Thus, the same
restrictions apply for FACCH Call Setup as for SDCCH allocation: it is limited
in the BCCH frequency band.</p>
</div>


<a name="jan2651516198" shape="rect"></a>
<div class="topic">
<h3>TCH allocation</h3>

<p>In a multiband Common BCCH segment, the TCH for a <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id011221#id011221" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id011221#id011221');return false" shape="rect" target="_blank">FACCH</a>
setup is always allocated in the BCCH frequency band of the segment. </p>


<p>When a TCH is allocated for an external handover in a multiband
Common BCCH segment, the search may be restricted among the BCCH frequency
band resources of the segment. This depends on the frequency band BCCH is
using. If the non-BCCH layer is regarded as a layer with less coverage (as
indicated by the positive value of the <span class="parameter-sem">Non BCCH Layer
Offset</span> parameter), only BCCH frequency band resources are used in TCH
allocation for external handovers.</p>
</div>


<a name="nov2621334522" shape="rect"></a>
<div class="topic">
<h3>TRX
prioritisation in TCH allocation</h3>

<p>The possibility to favour or avoid the BCCH TRX in call
assigning has been maintained to some extent in the segment environment. This
is examined after the BTSs of a segment have been compared on the basis of
their loads and their respective load parameters.</p>
</div>


<a name="nov2621342523" shape="rect"></a>
<div class="topic">
<h3>High
Speed Circuit Switched Data</h3>

<p>HSCSD resource allocation is made according to the capabilities
of an MS considering the radio conditions and the loads of the different resource
types. Among the BTSs that the BSC defines as reasonable, the TCH search is
performed so that the HSCSD channel configuration that best fulfills the request
is selected. </p>


<p>HSCSD is BTS-specific. </p>
</div>


<a name="nov26213435024" shape="rect"></a>
<div class="topic">
<h3>Shutdown
with forced handover</h3>

<p>When locking a single BTS of a segment, an intra-cell handover
is possible. If a BCCH-BTS of the segment is in the state <span class="state-sem">locked</span> when another BTS in the <a href="NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id013538#id013538" onclick="openSmallPopup(event,'NED?action=retrieve&amp;identifier=general_glossary&amp;edition=13&amp;language=en&amp;coverage=global&amp;encoding=xhtml_1_0&amp;component=data&amp;item=data&amp;pointer=id013538#id013538');return false" shape="rect" target="_blank">SEG</a>
is shut down, only an inter-cell handover is possible. The same applies when
the BCCH-BTS itself is shutting down.</p>
</div>


<a name="dec1531711421" shape="rect"></a>
<div class="topic">
<h3>Dual
Band</h3>

<p>Common BCCH replaces Dual Band. However, Dual Band is available
for cases where BTS site and cell definitions still use separate BCCHs for
each of the bands. Use Common BCCH if possible.</p>
</div>


<a name="jan265153194" shape="rect"></a>
<div class="topic">
<h3>GSM-WCDMA Inter-System Handover</h3>

<p>If GSM-WCDMA Inter-System Handover and Common BCCH are used together
the maximum amount of adjacent cells and frequencies in a BA list is 30.</p>
</div>
</div>
</div>
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