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Positioning</a></td>
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<h2>A interface</h2>

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<h3>Signalling
between BSC and MSC</h3>
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<p>The signalling between the MSC and the BSC in the A interface
is done using the BSSAP protocol. The existing BSSAP-LE Perform Location Response
message is modified for Support for US emergency call (E911) positioning.
The new positioning method is introduced to the information element Positioning
Data in the BSSAP Perform Location Response.</p>


<p>For more information, see <em>Location Services
in BSC</em> in the BSC/TCSM documentation.</p>
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