Sony Ericsson W950 Cell Phone User Manual


 
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White Paper W950
44 June 2006
Preliminary version - PA4
Performance requirements
Temporary degradation of service caused by
handover
During intra-UMTS Radio Access Network
handover or handover from UMTS Radio Access
Network to GSM/GPRS, degradation of service
should be no greater than during intra-GSM/GPRS
handover. The duration of the discontinuity
experienced by packet switched and circuit
switched real time services should be shorter than
that in the handover of voice calls over GSM/
GPRS.
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
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 W950
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
round-trip time. In 3G it is called Cell-ID + TA
(Timing in Advance).
Time difference measurement, involving several
base stations, can be used to obtain a more
accurate position.
Positioning methods are already used to support
location-based information services such as
©
YellowPages, restaurant guides, traffic
information, directions and friend finder
applications. Typically SMS or voice has been used
as delivery mechanisms. Java™ and MMS will add
new possibilities to deliver attractive location-
based applications.