Service Base Handover

UMTS on 2nd Carrier

Service Base Handover - Introduction

• This feature makes it possible to redirect speech users to GSM based on a Service Indicator (SI) that can be set per subscriber.

• This gives the operator the possibility to prioritize between subscriptions. Therefore, the operator can use this feature to use UMTS exclusively for data (PS R99 or HSDPA) while sending Speech calls to GSM.

• This feature works at the moment of the RAB establishment.

SBHO – Flow Chart • Speech Call is originated.

• RAB Assignment Request contains the information about the Service Indicator (SI) and Radio Access Bearer Type.

• Conditions SI = “should" and the RAB type = "speech only" are verified.

• If conditions are fulfilled then RNC sends a MEASUREMENT CONTROL with GSM information and compressed mode is started.

• If parameter condition utranThresh3aForcedGsm is fulfilled the Ue sent e3a. The parameter can be set to 0 to always fulfill the condition

• IRAT HO is executed.

SBHO – Service Indicator

• Shall Not: Neither Compressed Mode for GSM measurements nor connection transfer to GSM shall be initiated, regardless of any radio related reason to perform such actions.

• Should Not: Neither Compressed Mode for GSM measurements nor connection transfer to GSM shall be initiated, unless the quality/strength requires an inter-RAT transfer in order to save the connection

• Should: The system should immediately initiate required actions, e.g. compressed mode measurements to determine the correct target cell, in order to perform an inter-RAT transfer of the connection to GSM as soon as possible

• Missing value: The system may initiate required actions, e.g. compressed mode measurements to determine the correct target cell, when this is required for radio network reasons, e.g. bad signal quality (By default Should Not).

SBHO - Scenario

• It can be defined in either in UMTS F1 or UMTS F2 (850 or 1900)

• It can be used to reserve UMTS for packet data only and send speech call to GSM in one band (e.g. band reserved for HSDPA)

GSM

UMTS F1

UMTS F2

SBHO

SPEECH

HSDPA

HSDPA

HSDPA

SPEECH

PRACTICAL USE:

- Reserve UMTS for PS R99 / HSPDA

- Send Voice (CS) traffic in GSM