The Department of Defense (DoD) established the Modular
Open Systems Approach (MOSA) for procuring new systems
and upgrading existing systems. This approach is designed to
reduce acquisition and sustainment costs without sacri�cing
capability, and it is mandatory* for all DoD e�orts. The Space
Dynamics Laboratory (SDL) has the experience and the services
to help your agency integrate complex modular open systems.
*http://www.acq.osd.mil/se/initiatives/init_osa.html
SDL SERVICES
SDL is one of 14 University A�liated Research Centers (UARC), a
status that provides:
• Independence & objectivity
• Current operational experience
• Freedom from real and/or perceived conflicts of interest
As a trusted Government partner, SDL has had great success
facilitating and integrating MOSA in such programs as Space
Plug-and-play Architecture and Modular Open Network
ARCHitecture (SPA/MONARCH), Standard Network Adapter for
Payloads (SNAP), Modular Space Vehicle (MSV), Operationally
Responsive Space 2 (ORS2), Flexible Weapons (FLEX), and
Distributed Common Ground System (DCGS).
BENEFITS OF USING MOSA
MODULAR OPEN SYSTEMS APPROACH SERVICES
SDL/14-639A
1695 North Research Park Way • North Logan, Utah 84341 • [email protected] • www.sdl.usu.edu
S P A C E D Y N A M I C S L A B O R A T O R Y
REDUCED ACQUISITION &
SUSTAINMENT COSTS,NO CAPABILITY
SACRIFICE
Component Reuse
Facilitate Competition & Innovation
Incremental Capability Enhancement
Increased Ability to Upgrade
Resiliency to Requirement Changes
Enhanced Parallel Development
MOSA’S MODULAR DESIGN SAVES TIME & MONEY
Initial Cost
Integration Cost
Follow-on Cost
Reuse
Vendor-lock
Flexibility
TRADITIONALIMPLEMENTATION MOSA
LOW HIGH LOW HIGH
MOSA COST SAVINGS
By decoupling system components, MOSA provides cost savings
in the following ways:
• Reduces interface definition & design effort by using
standard interfaces
• Facilitates parallel development of hardware & software
• Reduces testing effort by consolidating changes
• Reduces system integration effort by allowing for individual
component verification
Using packet encapsulation minimizes change propagation. The carrier can change, but the packet remains the same.
01011
01100
10101
11110
01001
10110
TransportationModel
Data Model
01011
01100
10101
11110
01001
10110
OSI ModelApplication
Network process to application
PresentationData representation,
encryption, conversion
SessionInterhost communication,
session management
TransportEnd-to-end connections,
reliability, flow control
NetworkPath determination &
logical addressing
Data LinkPhysical addressing
PhysicalMedia, signal &
binary transmission
SPA Model
SPA Components
SPA Application Framework
xTEDS Interface
SPA Network
SSM
SPA Subnets
Ethernet, SpaceWire,I2C, USB, Serial
Hos
t Lay
ers
Med
ia L
ayer
s
Enables transport via truck, train, ship, plane, etc.
Enables transport via any data
protocol
1695 North Research Park Way • North Logan, Utah 84341 • [email protected] • www.sdl.usu.edu
OPEN STANDARDS
• Available to everyone
• Still interoperable with
proprietary solutions
• Developed & maintained
by the community
• Provider or implementation agnostic
• Allow for enhanced competitive
solutions
• Open to improvement through a
well-managed process
LAYERED ARCHITECTURE
• Network conceptual model uses
layered architecture
• Layers are developed independently
• Individual layers improve maintain-
ability & enable layer modification
with minimal impact
• Layer boundaries provide ideal
testability
• Simple architecture for ease of use
HARDWARE INDEPENDENT
• Portable Operating System Interface
constructs (POSIX & POSIX-like)
• Platform Abstraction Layer (PAL)
- Provides standardized application
programming interface (API) to the
operating system & hardware
- Localizes hardware-dependent code
in a single layer
- Allows for hardware & OS
modifications without impacting the
application code
- Enables quick & easy code
development for multiple software
or hardware platforms
NET-CENTRIC IMPLEMENTATION
• System of systems
- Communicates across heterogeneous
network media via packet encapsulation
- Abstracts complex interfaces into simple
network-accessible services
- Enables communication between systems
not originally designed to interoperate
- Uses logical addressing to ignore physical
location of components
- Enables dynamic discovery of available
network services
S O F T W A R E F O R C O M P L E X M O D U L A R O P E N S Y S T E M S