Honeywell Mark III Technical Overview page 58

The Mark III CMU has also been designed to support a future upgrade for new Gatelink technology. With
the advent of commercialized 2.4 GHz spread spectrum wireless communication, a new technology is
emerging for the airline industry for providing the ability to transmit very large data packets from and to the
aircraft when in the vicinity of a short range transceiver (commonly referred to as Gatelink). This new
technology has significant potential advantages in the future due to the high transfer rates (between 1 and 11
Mbits/ second), and the fact that this technology uses an unlicensed frequency band. This technology is
also being defined to interoperate with normal Intranet / Internet based systems, providing significant growth
capability for seamless interoperability with an airlines existing computer network. Honeywell has
recognized the potential of this new technology, and as such has designed into the Mark III CMU the ability
to upgrade the unit in the future to support such capability on the aircraft. This includes the use of using
one of the existing Ethernet ports within the Mark III CMU to communicate with the our wireless
transceiver/antenna which would be added to the aircraft in the future to support the Gatelink transmissions.
Similar to the Mark III CMU hardware, the Mark III Software
architecture within the unit has taken the next leap forward
in technology. Honeywell, which first introduced and
certified user-reconfigurable ACARS to the industry in 1991,
is providing a new degree of functionality in the area of user
reconfiguration. In addition to allowing airlines to add, delete
and modify such functions as the flight crew MCDU
screens, and downlink messages, the Mark III CMU
architecture incorporates what is referred to as the AOC
software completely within a database. Thus, logical
processing such as the definition of trigger algorithms for
sending messages automatically, are no longer defined in
software, but are part of the user reconfigurable database.
This provides an additional
degree of flexibility to airlines, allowing you to add or modify logical elements within the CMU. In contrast,
other systems require such logical processing changes to be performed by the CMU manufacturer (within
their AOC software). Thus such processing as determining flight phases (such as OUT, OFF, ON and IN
events), various exceedance conditions, and other logical processing for sending downlink messages can be
defined in a database, modifiable by either Honeywell or the airline. This flexibility to define logic conditioning
within the Mark III CMU has been expanded to other areas of the system as well, such as allowing
increased flexibility in controlling what is displayed on the MCDU; and conditional processing for determining
what information to include in downlinks and printer based reports. All such capability is able to be
performed without impacting the certification status of the unit. All of the Mark III CMU operational software
and database are software loadable into the unit, allowing updates without removing the system from the
aircraft. In addition, due to the size of the memory on the Mark III CMU, the Mark II CMU is capable of a
single database across all of the aircraft in an airline's fleet of aircraft. This will allow an airline to have not
only the same software but also the same database (thus identical and single configuration) across the
complete fleet.
The Mark III CMU also incorporates a certified database which is used to implement changes to certified
components easily, versus requiring software modifications. As an example the ARINC 623 ATC messages
are contained in this certified database, which would also be expanded in the future as other ATC messages
become operational.
The Mark III CMU also has added in special software and hardware that supports Honeywell's NZ FMS /
CDU, used on many regional aircraft such as the Embraer 135/145 as well as other types of aircraft. These
aircraft which do not use the traditional ARINC 739 protocol, can now have the latest in Datalink technology,
through the use of the Mark III CMU's special processing for such aircraft types.
HONEYWELL Aerospace Electronic Systems
Use or disclosure of information on this page is subject to the restrictions on the title page of this document.
GBST Reconfiguration Tool Provides
Airlines complete flexibility and
control over changing AOC
algorithms, through the use of Pseudo
software language.
Mark III
CMU
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