General operational considerations
Mechanisms defined to support service continuity between different radio systems or radio access modes should effectively cope with a number of coverage scenarios:
•Limited coverage in a “sea” of coverage pro- vided by another radio system or radio access mode.
•Selective operation at a geographical boundary, with extensive UMTS Radio Access Network coverage on one side, and extensive coverage from another radio system on the other side.
•Geographically colocated areas of UMTS Radio Access Network coverage and another radio system.
Performance requirements
Temporary degradation of service caused by handover
During
Requirements on multiple bearer services handover from UMTS radio access network to
GSM/GPRS
Consideration must be given to services that may involve multiple bearer services (and simultaneous sessions). The mapping between UMTS Radio Access Network bearer services and GSM/GPRS bearer services depends on many factors such as data rate, delay constraints, error rate etc. In the
White Paper M600
event that certain UMTS Radio Access Network bearer services cannot be handed over to GSM/ GPRS, the handover of some of the bearers to maintain the service should not be precluded.
In the case where a user equipped with a dual mode terminal is in UMTS Radio Access Network coverage, and has multiple PDP contexts activated (for instance to support multimedia), then it is preferable to handover one PDP context, rather than dropping all of them.
As a first priority only the PDP contexts which have an associated QoS that can be supported by the GSM/GPRS should be candidates for handover.
If there are still multiple PDP contexts as “handover candidates”, then the operator should choose which PDP is maintained. When roaming, the serving network should make this decision. The operator may choose to either:
•Drop all of the PDP contexts.
•Choose one based upon criteria such as dura- tion, amount of traffic transferred, etc.
Handover in M600
This phone is compliant with the 3GPP R99 December 2002 release.
GSM to UMTS
The product supports circuit switched voice handover from GSM to UMTS.
UMTS to GSM/GPRS
The product supports packet switched data handover and circuit switched voice handover from UMTS to GSM/GPRS.
Positioning
The basic cost efficient positioning method available in 3G networks relies on measuring
Time difference measurement, involving several base stations, can be used to obtain a more accurate position.
58 | February 2006 |