Moby Dick Consolidated System Integration Plan

D0103v1.doc Version 1 6.7.2003
No AAAC mechanism is involved in this case, so the registration module will not be involved in this
case.
The L2 resources of the current technology in use will be released if needed (see section ‘Handover
Execution’). Then the message TERMINATE_NETWORK_CONNECTION_ACK should be sent back to
the NCP, after the detach procedure has been executed, with the status as parameter.
4.1.2.2.5 Manual Handover block
NCP
Set
Network
Preferences
Set
Handover
Preference
Manual
Handover
Network
Environment
Infos
Explicit
Connectivity
Request
MTNM
Set
Network
Preferences
Set
Handover
Preference
Network
Environment
Infos
Manual
Handover
Fast Handover module
Network device drivers
TDCDMA WLAN Ethernet
Figure 8: Manual Handover block
When the command MANUAL_HANDOVER_REQ is received from the Manual Handover block of the
NCP (only when handover preference is set to manual and both mode), the decision to execute the
Handover is taken immediately, because every necessary control have been done at the NCP level (in
particular, the signal levels for WLAN and TD-CDMA are higher than the predefined thresholds
WLAN_threshold and TD-CDMA_threshold).
If the handover preference is set to manual, handover among two different “access point” of the same
Network technology will also be automatically considered, for WLAN and TD-CDMA (as explained in
the description of NCP).
Every n milliseconds, the following actions will be taken, if the current Network Technology is WLAN or
TD-CDMA, and only if the current signal level is lower to a predefined threshold (WLAN_threshold and
TD-CDMA_threshold respectively: we don’t want to trigger handover too often if the current connection
is good enough) :
(we take the example of WLAN, but the same applies to TD-CDMA) we compare the information in
Network Environment Infos block for the current WLAN “access point” and the WLAN “access point”
best candidate for handover. If current WLAN signal to noise ratio + delta_WLAN < best candidate
WLAN signal to noise ratio, a decision for handover is taken. We introduce delta_WLAN, because we
don’t want to handover to a WLAN new “access point”, which signal level is not significantly better.
(The same relation is introduced for TD-CDMA: TD-CDMA signal level + delta_TD-CDMA < best
candidate TD-CDMA signal level).
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