User`s guide

Agilent PXT Wireless Communications Test Set
User’s Guide
188
Limitations
No Support for SRVCC with PS Handover
This SRVCC solution cannot perform a handover of both the IMS call to CS and PS Handover at the same
time. If IP connectivity is required at another bearer following the handover, then the Routing Area Update
procedure can re-establish it.
No Support for Audio Transcoding
If end-to-end audio testing is required, the audio codec used before the handover is the only one which can
be used post-handover.
Should a change in audio codec be required the ‘Echo’ speech source should be selected once the 8960 is
in the ‘Handover’ state. This breaks the end-to-end audio path but permits the UE to experience a change in
codec.
Note that pressing the SRVCC ‘Setup Inbound’ button to prepare the 8960 for the inbound handover
automatically changes the speech source to IMS. In WCDMA it is also not possible to change this setting
post-handover.
SMS over SGs
SMS over SGs is an interim solution to realize the transmission of native SMS from CS infrastructure over
the LTE radio network. Without SGs support, a UE, camped on the LTE network would need to change its
radio access technology back to 2G/3G in order to process SMS service. SG is a new interface (defined in
Release 8.0 of the 3GPP standards) between the MME and the MSC. The SMS is transferred via SGs to
MME and carried in NAS signaling to the UE, avoiding the need to execute fallback to a 2G/3G network.
To transmit SMS from LTE to a GSM network, reference this information:
http://wireless.agilent.com/rfcomms/refdocs/gsmgprs/gprsla_gen_bse_sms_over_sgs.html
.
To transmit SMS from LTE to a WCDMA network, reference this information:
http://wireless.agilent.com/rfcomms/refdocs/wcdma/wcdma_gen_bse_sms_mt.html
.
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