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ROSS
3.3 Modem Interaction with ROSS
The Vessel equipment must bond together blending a mix of independent processes forming a
partnership of exchanged information and controls. This unique partnership builds a cohesive
system even though all run independent process. Each component has startup, normal and idle
modes of operation but still mesh together in timed acknowledged sequences.
The follow functional lists only describe the two Comtech units omitting the antenna control
system for lack of function detail. Each list is a step-by-step description on the basic processes
and how they interact forming the system functionality. This section describes what different
type of sequencing happens between cold and hot initializations.
3.3.1 Modem Initialization
The modem plays a key role in the communications chain as it must perform quickly through the
active transformation of pushed configurations file from ROSS. The modem has two different
modes of processing configurations files, one at boot time the other at run time. Each process
deferrers in sequence based on the initialization execution point.
Previously described the ROSS unit also has two types of execution points requiring long and
short initializations, however during the operational mode the ROSS unit pushes configuration
files to the modem which must be timed correctly for proper execution. During cold boot
(applied input power) all system components will typically complete initialization at different
times presenting a possible problem if the mediator (ROSS) pushed information too soon. ROSS
must wait for valid responses before sending controls or configurations prematurely resulting in
lost information. This validation before send eliminates repetitive processing streamlining the
initialization sequence.
Modem Cold Boot:
1. The Comtech modem stores two boot images, one is for the base modem processes and
the other is the IP Interface module (router). On power up both are loaded simultaneously
with base modem monitoring the boot state of the IP interface. The IP Interface module
boots the OS reading the FLASH parameter configuration file while the base modem
reads its last state values from NVRAM.
2. The Base modem first loads last state (stored) parameters which could have TX enabled,
however the transmit enable is held muted through a hardware control line from the IP
interface module until it completes its boot check before releasing. This prevents
premature transmission until the IP Interface has booted and finished rendering
configured states.
3. Once the IP Interface has finished booting it reads a stored parameter file from FLASH
sending two base modem configuration index scripts, Modem Group Configuration
(MGC) and Outdoor Group Configuration (OGC). These two loads contain the complete
IDU/ODU configuration sets.
4. Next the IP Interface loads Home State (subset of transmission values) parameters from
FLASH releasing the hardware mute signal.
Comtech EF Data, Vipersat Products
MN/13070
Page 23 of 87
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