Moby Dick Consolidated System Integration Plan

D0103v1.doc Version 1 6.7.2003
When the decision to execute a handover is taken, we enter in a phase common to manual and automatic
handover, which we will call Handover Execution,.
4.1.2.2.6 Automatic Handover block
MTNM
Set
Network
Preferences
Set
Handover
Preference
Network
Environment
Infos
Automatic
Handover
Fast Handover module
Network device drivers
TDCDMA WLAN Ethernet
Figure 9: Automatic Handover block
Every n milliseconds, the following actions will be taken:
The automatic handover will be considered if the handover preference, in the Set Handover preference
block, is set to automatic or both.
The automatic handover decision algorithm will consider the current Network technology used,
information from the Set Network Preferences block and from the Network Environment Infos block; to
decide if a handover should occur.
The following table gives the different possibilities for the Network preferences, and it will be used to
illustrate the decision algorithm.
Network Preferences TD-CDMA 1 TD-CDMA 2 TD-CDMA 3
WLA N 1 Ethernet 3 (case I) Ethernet 2 (case II)
WLAN 2 Ethernet 3 (case III) Ethernet 1 (case IV)
WLAN 3 Ethernet 2 (case V) Ethernet 1 (case VI)
Table 1: Network Preferences
Given the current technology in use, the Network technologies with a higher preference level will be
considered from top to bottom; and if one is appropriate, the handover decision will be taken. For
example, in case IV, if the current technology in use is WLAN, only Ethernet will be considered as a
potential handover technology. And in case V, if the current technology in use is WLAN, TD-CDMA will
be considered first, and Ethernet second, as a potential handover technology.
In the case of WLAN and TD-CDMA, if no Network technology with a higher preference level is
selected for handover, a handover within the same Network Technology will be considered, to a new subnetwork;
but only if the signal level is lower than a predefined threshold (WLAN_threshold and TD-
CDMA_threshold respectively).
The 3 following situations can happen:
• Ethernet is the current Network Technology: higher preference level Network technologies are
considered.
D0103v1.doc 24 / 168