kbps.

3

D8PSK

TDMS

Same as Mode 2 except the voice is now digitized and

 

 

 

the Medium Access changes. Currently. Discussions are

 

 

 

underway to determine if Mode 3 will be deployed. This is

 

 

 

currently only a U.S. program, with earliest use for

 

 

 

datalink scheduled for 2011 (but potentially 4 years

 

 

 

earlier for voice)

4

GMSK

STDMA

Modulation and Medium Access change and output is

 

 

 

only 19.2 kbps. Mode 4 is being considered as one of the

 

 

 

means to perform ADS-B communication. It is currently

 

 

 

expected that Mode 4 may not impact CMUs, but this is

 

 

 

still to be determined.

The baseline Mark III CMU supports Mode 0 (an analog line to the MSK modem) and Mode A (a W429 link to the radio which has an embedded MSK modem. Mode 2 utilizes a different modulation scheme (D8PSK) allowing a throughput increase from 2.4 kbps to 31.5 kbps. Transition to VDLM2 functionality only requires an operational software upgrade (i.e., no hardware upgrade is required). ). VDL Mode 2 is offered as a separate (optional) software package.

PCMCIA Data Loading

The Mark III CMU has a PCMCIA connector accessed through the front panel. Utilization of this interface for fast data-loading capability.

Ethernet

The Mark III CMU is hardware provisioned for up to four 10 Base-T Ethernet ports. These ports can be utilized in the future for a variety of purposes for high speed data communication.

ARINC 761 SATCOM

As the second generation satellite communications specification (ARINC 761) becomes fully defined, The Mark III CMU hardware is designed to support such future SATCOM systems, with software only changes.

Mil-STD 1553

The Mark III CMU has an interface to a MIL-STD 1553 bus. Software access to this interface is a potential upgrade to support interfaces on various military aircraft.

Gatelink

ARINC 751 defines the specification for Gatelink, a wireless LAN interface between the aircraft and the terminal. The Mark III CMU is hardware provisioned to support a Gatelink interface. Honeywell is currently working on additional upgrade modifications (to include large mass memory and new additional circuit card assembly) which would be provided to support a self contained Gatelink capability, with a direct interface to a TWLU.

UHF

The Mark III CMU has a UHF modem installed as part of the basic Mark III CMU hardware. This has been included such that if UHF becomes a medium that can provide datalink services, such future capability could be implemented without modification to the hardware.

Weather Graphics

The ability to uplink graphical weather information is an important feature for certain datalink users, particularly in the business jet market. From an industry perspective, there isn't a standard mechanism for delivering graphical weather capability. In addition, weather graphics is currently considered as being cost prohibitive relative to air transport operation. However, Honeywell plans to monitor the industry work in this area and potentially offer a graphical weather capability as a software upgrade. The Mark III CMU does

HONEYWELL Aerospace Electronic Systems

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Honeywell Mark III manual Pcmcia Data Loading, Arinc 761 Satcom, Mil-STD, Weather Graphics