Honeywell International Inc. WLUWIFIM010 Manuale Utente
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HIF-1472R6(1)
Boeing decides what the correct country settings need to be and agree on the parameters and rules
Honeywell uses to decide when to change the configurations. Airport identifiers shall map to configuration
settings. Airlines need be able to configure parameters that vary based on where the aircraft is used and
security. Examples of this include which airports provide Gatelink to the airline, what the associated ESSID
are, TWLU and CWLU digital certificate keys. An overview of the two modes of operation is given below.
7.3.1. TWLU Operation
The TWLU radio is enabled when the aircraft is on the ground, at approved airports, that the airline has
Gatelink agreements with. It is disabled while the aircraft is in the air. The WLAN Manager monitors,
configures, and controls the TWLU.
After an aircraft lands, the WLAN Manager:
detects aircraft is on ground (Aircraft parameter:: in air)
determines which airport the aircraft is at (Aircraft parameter: airport identifier parameter)
looks up the airport settings in the CISS AMI
configures the TWLU at that airport with:
o ESSID, RF power/mode, encryption setting, etc.
o Uploads necessary Gatelink public key certificate trust anchor
o Uploads necessary Gatelink public key certificate trust anchor
verifies TWLU configuration and enables RF radio
An aircraft lands at a Gatelink enabled airport that it is registered to use. The TWLU is configured and radio
enabled after landing. The TWLU begins sending IEEE802.11 probes. Gatelink APs send beacons and probe
responses. The TWLU associates with a Gatelink Access Point. IEEE802.11i/WPA2 authentication and
encryption is performed. Upon successful completion, the TWLU obtains an IP address from Gatelink and
begins its operation as a NAT/PAT network router. The wireless connection can roam to other Gatelink Access
Points as the aircraft moves.
7.3.2.
CWLU Operation
The CWLAN is available during ground and cruising flight phases. CWLUs are configured to their default
country settings, for operation in the air. They are disabled when the aircraft is below an altitude threshold
level (e.g. 10,000 AGL).
After aircraft landing, the WLAN Manager:
detects aircraft is on ground (CDN parameter In Air)
determines which airport the aircraft is at (CDN avionics airport identifier parameter)
looks up the airport in its tables
configures the CWLU:
o
RF power/mode, encryption setting, etc.
verifies CWLU configuration
enables RF radio
After aircraft take off, the WLAN Manager:
detects aircraft is in the air (CDN parameter In Air)
disables the CWLU RF outputs
configures the CWLUs to default settings:
o
RF power/mode, encryption setting, etc.
verifies CWLU configuration
after reaching altitude threshold (CDN altitude parameter, 10,000 AGL), enables CWLU RF radios