Troubleshooting Handovers

Last updated: January 16, 2009

• Physical Channel Reconfiguration
• Transport Channel Reconfiguration
• System Handovers
• Radio Bearer Reconfiguration

Physical Channel Reconfiguration

• See Physical Channel Reconfiguration Operating Considerations .
• You must be on a call to perform a physical channel reconfiguration.
• 3GPP TS 25.331 v5.17.0 s8.6.6.28 states that the UE's behavior is undefined if the network sets the Timing Indication IE to Initialise on a non-hard handover (i.e. where the UARFCNs and one or more Primary Scrambling Codes remain unchanged as part of the reconfiguration). Thus, if you perform a Physical Channel Reconfiguration with PCR Timing Indication (CFN Handling) set to Initialise, and the handover downlink and uplink channels are the same as the current downlink and uplink channels, the UE may drop the call, ignore or reject the reconfiguration request, or report a reconfiguration failure.

• When the test set orders a Physical Channel Reconfiguration, it takes a finite amount of time for the test set to move to and settle at the new frequency. When the Physical Channel Reconfiguration is ordered, most UEs wait a time of T312 at the new frequency before determining that the handover has failed (T312 is signalled by the test set in SIB1 with a value of 5 seconds). If your UE does not wait once moving to the new frequency, the handover may fail. If it does, set PCR Activation Time as needed to cause the UE to wait until the test set has moved to the new frequency (a setting of 100 (100 x 10 ms = 1 s) is usually sufficient). Do not set PCR Activation Time to a value other than 0 unless necessary, as it slows down the handover procedure.

• Ensure that the handover downlink and handover uplink channels are set to proper values for your UE. Note that the default DL Channel of 10700 and default handover downlink channel of 10730 are 6 MHz apart (the default uplink channels are also 6 MHz apart). If you wish to handover to channels that are 5 MHz from the default channels, set the handover downlink channel to 10725 and handover uplink channel to 9775 .
• If the test set recognizes the physical channel reconfiguration as illegal for any reason, an error is posted, the reconfiguration is rejected and the test set remains in its state prior to the initiation of the reconfiguration. Conversely, if the UE simply does not respond as expected during a reconfiguration, an error is posted and the test set proceeds with the procedure as if the expected response was received.

Transport Channel Reconfiguration

• See Transport Channel Reconfiguration Operating Considerations .

• The Transport Channel Reconfiguration provides three main functions:

  • Switching Between Symmetrical RMCs while on an RB Test Mode Connection . You must be on a (non-HSDPA/non-HSPA) RB test mode symmetrical RMC call to perform a transport channel reconfiguration between RMCs.
  • Changing Parameters that Require Cell Off Operating Mode or Idle Connection Status while on a Connection . You must be on an RB test mode symmetrical RMC connection (non-HSDPA, HSDPA or HSPA) to change these settings.
  • Changing HSPA Parameters that Require Idle Connection Status while on a Connection ( lab application or feature-licensed test application only ). You must be on an HSDPA or HSPA RB test mode connection to change these settings.
• 3GPP TS 25.331 v5.17.0 s8.6.6.28 states that the UE's behavior is undefined if the network sets the Timing Indication IE to Initialise on a non-hard handover (i.e. where the UARFCNs and one or more Primary Scrambling Codes remain unchanged as part of the reconfiguration). Thus, if you perform a Transport Channel Reconfiguration with TCR Timing Indication (CFN Handling) set to Initialise (or set to Auto and TCR Default DPCH Offset (DOFF) is set to a value other than the Current DPCH Offset ), and the handover downlink and uplink channels are the same as the current downlink and uplink channels, the UE may drop the call, ignore or reject the reconfiguration request, or report a reconfiguration failure.
• Ensure that the handover downlink and handover uplink channels are set to proper values for your UE. Note that the default DL Channel of 10700 and default handover downlink channel of 10730 are 6 MHz apart (the default uplink channels are also 6 MHz apart). If you wish to handover to channels that are 5 MHz from the default channels, set the handover downlink channel to 10725 and handover uplink channel to 9775 .

System Handovers

This functionality is only available in GSM/GPRS_W-CDMA fast switching test and lab applications.

• The system handover functionality allows you to handover to a GSM voice call from any of the following connection types:

  • AMR Setup
  • (non-HSDPA/non-HSPA) Radio Bearer Test Mode
  • HSDPA Radio Bearer Test Mode with CN Domain set to CS Domain ( lab application or feature licensed test application only )
  • HSPA Radio Bearer Test Mode ( lab application or feature licensed test application only )

  You must be on one of these types of connections to perform a system handover.

• Before performing the handover, you must ensure that the GSM/GPRS format is set to Active Cell operating mode.
• When performing a handover from W-CDMA RB test mode to a GSM voice call with RB Test Mode to GSM Handover Alerting State set to On , the UE will ring. You must answer the ring for the connection to be completed and testing to progress.
• When performing a handover from W-CDMA RB test mode to a GSM voice call with RB Test Mode to GSM Handover Alerting State set to Off , when the handover is completed, the connection is left in the RR Connected state. Data loopback (for BER testing) is available in this state, but voice echo is not.
• If your UE does not send a W-CDMA layer 2 acknowledgment for the Handover From UTRAN command, you must set Wait for RLC Ack of Handover From UTRAN to Off . Otherwise, the test set will not continue with the handover until it receives the expected acknowledgment, and the handover will fail.
• Presetting the test set while operating in the W-CDMA format will not reset the System Handover parameters to their default settings. Presetting the test set while operating in the GSM/GPRS format will reset these parameters to their default values.
• When operating in the W-CDMA format, the System Handover parameter settings are not saved when using the SAVE REGISTERS utility.

Radio Bearer Reconfiguration

• See Radio Bearer Reconfiguration Operating Considerations .
• The Radio Bearer Reconfiguration allows you to handover from a CS Domain or CS/PS Domain HSDPA RB Test Mode connection or HSPA RB Test Mode connection to a (non-HSDPA/non-HSPA) symmetrical RMC.
• 3GPP TS 25.331 v5.17.0 s8.6.6.28 states that the UE's behavior is undefined if the network sets the Timing Indication IE to Initialise on a non-hard handover (i.e. where the UARFCNs and one or more Primary Scrambling Codes remain unchanged as part of the reconfiguration). Thus, if you perform a Radio Bearer Reconfiguration with RBR Timing Indication (CFN Handling) set to Initialise (or set to Auto and RBR Default DPCH Offset (DOFF) is set to a value other than the Current DPCH Offset ), and the handover downlink and uplink channels are the same as the current downlink and uplink channels, the UE may drop the call, ignore or reject the reconfiguration request, or report a reconfiguration failure.
• Ensure that the handover downlink and handover uplink channels are set to proper values for your UE. Note that the default DL Channel of 10700 and default handover downlink channel of 10730 are 6 MHz apart (the default uplink channels are also 6 MHz apart). If you wish to handover to channels that are 5 MHz from the default channels, set the handover downlink channel to 10725 and handover uplink channel to 9775 .