1. Digital IF for SATCOM Terminals Introduction
VIEWING INSTRUCTIONS:
1. Print out these “Notes Pages”
2. “Slide Show” / “From Beginning” or “Slide Show” / “From Current Slide”
3. Use “Notes Pages” to supply context to animations in presentation.
A.J. Vigil, Ph.D.
Senior Scientist, Systek
Senior Systems Engineer
Product Director, Satellite Communications Systems (PD-SCS)
(703) / DSN (312)
2011 February 04 Friday

2. Digital IF = Digital Intermediate Format
Motivators
Concept
Feasibility
Technical Readiness Level
Enterprise Terminal Architecture
Enterprise Terminal Cost-Benefit
Mid-Size Terminal Architectures
Small Terminal Architectures
Why an Open Commercial Standard?
Standardization Objectives
Standards Process
Progress & Activity
Why do it
What it is
Maturity level
Architectures & Cost-Benefit
Standardization
Progress & Activity
L-Band IF: Intermediate Frequency
Digital IF: Intermediate Format

3. Introduction: Motivators
Traffic Demand
Link Count
Transmission BW (BandWidth)
Cost & Schedule
Development
Production
Deployment
Operations
Floor Space
SWAP (Size, Weight And Power)
VSAT (Very Small Aperture Terminals)
COTM (Comm[unications] On The Move
Operational Complexity
RF Performance
New Capability Insertion
We launch projects to solve problems like these.
Any of our projects addresses one or more of these problems.
Digital IF is unique in that it addresses all of these challenges.
Included under “Cost & Schedule” as part of “Operations”
- accommodate ever increasing OPTEMPO
Included under “New Capability Insertion”
- enhance net readiness

4. Digital IF: Concept L-Band IF Digital IF Waveform Analog
Digitally Sampled
Capacity
Bandwidth
Sampling Rate
Fidelity
Dynamic Range
Sample Size
Frequency
Waveform Center Frequency
Center Frequency Tag
Power
Waveform Power
Power Tag
Transport Medium
Coaxial Cable
Analog Fiber
Ethernet Twisted Pair
Ethernet Digital Fiber
Modem
Mixed-Signal
Pure DSP Engine
Switch
Ethernet
Combine / Divide
Digital
IFL
Digital Fiber
Conversion
L-Band to RF
Digital to L-Band or RF
Acronym
Intermediate Frequency
Intermediate Format
What is Digital IF?
Context here is about SATCOM in general and MILSATCOM in particular.
Today we move electromagnetic signals around our terminals, from modem to antenna, at an IF – Intermediate Frequency - using coax.
Suppose instead that we digitized those signals and moved them around our terminals using Ethernet over CAT6 cable.
This table shows how Digital IF compares with the L-band IF we use today.
Tha’t’s Digital IF – Digital Intermediate FORMAT for moving carrier & aggregate waveforms around our terminals, from modems to antenna & antenna to modems.

5. Digital IF: Feasibility
L-Band IF
Digital IF
DSP
125 MHz BW
- lights up WGS transponders
90 dB Dynamic Range
- cert-level performance
250 Msamples / sec
x 16 bits / sample
= 4 Gbits / sec
<< 10 Gig Ethernet
Switches
L-Band Matrix Switch
COTS Ethernet Switch, 288x288
- 10 Gig Ethernet Capable
Standards & Precedents
MIL-STD
NATO STANAG 4486
Cellular Base Stations
WGS Channelizer
ANSI/VITA (SIGINT)
Technology Growth
Linear
Exponential
- think “Moore’s Law”
What makes us think this is even possible?
- DSP perspective
- switching perspective
- standards & precedents
- forward looking expectations
This is more than just feasible. It’s a no-brainer, and it’s a must-do.
Feasible now
Strong precedents
Ideal for sustained growth

6. Digital IF: Technology Readiness Level
CERDEC FAST Prototypes
Underlying Technology
A/D, D/A, DSP, FFT, IP, Ethernet
SNMPv1, SNMPv3, XML over IP, secure XML over IP
Technology Readiness Level
Description
6. System/subsystem model or prototype demonstration in a relevant environment
Representative model or prototype system, which is well beyond the breadboard tested for TRL 5, is tested in a relevant environment. Represents a major step up in a technology's demonstrated readiness. Examples include testing a prototype in a high fidelity laboratory environment or in simulated operational environment.
Technology Readiness Levels in the Department of Defense (DoD) (Source: DoD (2006), Defense Acquisition Guidebook)
Technology Readiness Level
Description
1. Basic principles observed and reported
Lowest level of technology readiness. Scientific research begins to be translated into applied research and development. Example might include paper studies of a technology's basic properties.
2. Technology concept and/or application formulated
Invention begins. Once basic principles are observed, practical applications can be invented. The application is speculative and there is no proof or detailed analysis to support the assumption. Examples are still limited to paper studies.
3. Analytical and experimental critical function and/or characteristic proof of concept
Active research and development is initiated. This includes analytical studies and laboratory studies to physically validate analytical predictions of separate elements of the technology. Examples include components that are not yet integrated or representative.
4. Component and/or breadboard validation in laboratory environment
Basic technological components are integrated to establish that the pieces will work together. This is "low fidelity" compared to the eventual system. Examples include integration of 'ad hoc' hardware in a laboratory.
5. Component and/or breadboard validation in relevant environment
Fidelity of breadboard technology increases significantly. The basic technological components are integrated with reasonably realistic supporting elements so that the technology can be tested in a simulated environment. Examples include 'high fidelity' laboratory integration of components.
6. System/subsystem model or prototype demonstration in a relevant environment
Representative model or prototype system, which is well beyond the breadboard tested for TRL 5, is tested in a relevant environment. Represents a major step up in a technology's demonstrated readiness. Examples include testing a prototype in a high fidelity laboratory environment or in simulated operational environment.
7. System prototype demonstration in an operational environment
Prototype near or at planned operational system. Represents a major step up from TRL 6, requiring the demonstration of an actual system prototype in an operational environment, such as in an aircraft, vehicle or space. Examples include testing the prototype in a test bed aircraft.
8. Actual system completed and 'flight qualified' through test and demonstration
Technology has been proven to work in its final form and under expected conditions. In almost all cases, this TRL represents the end of true system development. Examples include developmental test and evaluation of the system in its intended weapon system to determine if it meets design specifications.
9. Actual system 'flight proven' through successful mission operations
Actual application of the technology in its final form and under mission conditions, such as those encountered in operational test and evaluation. In almost all cases, this is the end of the last "bug fixing" aspects of true system development. Examples include using the system under operational mission conditions.
Technology Readiness Level
Description
8. Actual system completed and 'flight qualified' through test and demonstration
Technology has been proven to work in its final form and under expected conditions. In almost all cases, this TRL represents the end of true system development. Examples include developmental test and evaluation of the system in its intended weapon system to determine if it meets design specifications.

7. Digital IF: Enterprise Terminal Architecture
L-Band
modem
IFL
IFL
BUC
BDC
HPA
LNA
IFL = Inter-Facility Link o
192 o 24 o o 24
L-Band
modem
L-Band Switch
Combiner / Divider o
IFL
IFL
BUC
BDC
HPA
LNA
Dig
/ L o
Dig IF
modems
Dig
/ L
Dig
/ L
BUC
BDC
HPA
LNA
How do we grow with Digital IF?
Baseline – what we’re building today
- significant investment – painful to walk away from
First Insertion: introduction
- problem solved: Tx uplink noise sue to L-band combining
- problem solved: physical L-Band switch limitation of 192 carriers,
enabling disproportionately more
First Upgrade: moves Digital-to-L-band converters to antenna shack
- solves IFL (Inter-Facility-Link) dynamic range problem that you
can’t solve at L-band
Next Upgrade: migrates to direct RF conversion as it matures
(L-band conversion is mature today)
Conversion Integration: integrates direct RF conversion into HPA & LNA
as direct RF conversion further matures
- Ethernet all the way to LNA & HPA
Migration is gradual & sensible
- leverages L-Band investment rather than discarding it
- today’s equipment remains compatible with the architecture,
indefinitely if necessary o
Ethernet Switch
Combiner / Divider
Dig
/ RF
HPA
LNA
Dig IF
modems
HPA
LNA
traffic
Digital IF
L/-Band RF

8. Digital IF: Enterprise Terminal Cost-Benefit
modems through block conversion
L-Band IF
Digital IF
Modems, 192 each
$1,920,000
$ 960,000
Switch Matrix Combiner/Divider, 192x24
$3,200,000
Ethernet Switch, 288 x 288, 2 each
$ 200,000
Digital Combiner/Dividers, 24 each
$ 240,000
Digital / L-band Converters, 24 each
$ 600,000
Coax Cables, L-band Amps
$ 50,000
Totals, modems to RF
$5,170,000
$2,050,000
Assumptions
Significant components only
Modem cost is half
Modem conversion cost is trivial
Ethernet Switch – layer 1 – quoted
Digital combiner/dividers $10k / aggregate
Digital / L-band Converters $25k per pair
All are conservative
Conclusions
Save > $3M / terminal, incl modems
Save > $1M / terminal sinking modem cost
Conservative; yet to consider
IFLs
Future insertions
Performance burdens
Facility burdens
How much can be saved on terminals large scale enterprise terminals?
> $3.12 M on a terminal starting from scratch
> $1.20 M on a terminal walking away from existing modems
There is a potential here for recovering
from budget cuts & funding delays
Additional benefits not included:
eliminate IFLs altogether
advantage on every new insertion in terms of
reduced development cost & schedule
solve performance problems that can’t be solved,
economically, at L-band
reduce facility footprint & power/HVAC demands
Cost-benefits for small & mid size terminals pending.

9. Digital IF: Mid-Size Terminal Architectures
Dig IF
modem
bank o
Dig
/ L
BUC
BDC
HPA
LNA
Dig IF
modems
prototype equipment under development
Dig IF
modems
Dig IF
modems
Dig
/ L
BUC
BDC
HPA
LNA
Dig IF
modems
Dig
/ RF
HPA
LNA
Digital IF is flexible.
Prototypes are under development at CERDEC S&TCD, Aberdeen, MD, with OSAT (over satellite) prototype testing anticipated for early 2012.
This will be a proof-of-concept prototype test, not a “Digital IF” standard test, per se, nor a production-ready equipment test.
PD-SCS does not control this, but are working with CERDEC on it. We expect this to
- demonstrate the feasibility of a digital IF terminal
- offer “lessons learned” that feed into the open commercial standardization process.
Medium terminal – illustrates redundant failover configuration
HPA
LNA
medium sized terminal, modems daisy chained with fail-over redundancy
traffic
Digital IF
L/-Band RF

10. VSAT (Very Small Aperture Terminal) or COTM (Comm On The Move)
Digital IF: Small Terminal Architectures
Dig IF
modems
Dig
/ L
BUC
BDC
HPA
LNA
Dig
/ RF
HPA
LNA
HPA
LNA
small terminal
Small terminal – simpler configuration, simpler migration. Here, a single modem offers enough multiple modem functions so that a dedicated combiner/divider is not required.
VSAT & COTM – Digital IF offers a huge SWAP advantage
Take away: Digital IF is for terminals of all types & sizes.
ANECDOTE:
- DCATS thinks this would be good for WIN-T on account of SWAP
- WIN-T thinks this would be good for DCATS on account of floor space!
Dig IF
modem
HPA
LNA
VSAT (Very Small Aperture Terminal) or COTM (Comm On The Move)
traffic
Digital IF
L/-Band RF

11. Why an Open Commercial Standard?
Plug & play interoperability
Faster procurement path
Less procurement expense
Wider participation
Government
Industry
Level playing field
Standard comes first
Full COTS basis
Technology development is mature
Government procurement cycle includes
- RFI
- procurement docs – spec, SOW, etc.
- solicitation
- source selection
- negotiation
- development
- schedule slips
- FAT (First Article Test)
- standardization (last!)
+ Sometimes equipment can be obsolete before it is fielded.
+ This process also discourages multiple vendors.
Open commercial standardization, on the other hand, is
- public
- interactive
- industry-wide
- as fast as the business case makes it
- standards can be revised to accommodate growth and add features
+ costs the Government precious little compared to the alternative
+ offers each Government stakeholder any level of participation it chooses
+ likewise each industry shareholder

12. Digital IF: Standardization Objectives
CONOPS
Reduced equipment complement
Simplified installation
Simplified test processes
Reduced operational complexity
Practical remote CMA
Economy
Development costs & schedules
Equipment / production costs
Deployment costs & schedules
Terminal footprint
SWAP
Migration
Minimal operational disruption, if any
Retain legacy infrastructure value
Arbitrarily scalable
Initial Capability
Digital conversion to L-Band
min 125 MHz contiguous BW
16 bit resolution
Existing technology only;
Engineering, not development
Growth – Inherent Capability
No limit to link count
No limit to bandwidth
Common to all terminal types & sizes
RF Performance
Resolve IFL DR bottleneck
Non-additive Tx noise floor
Eliminate linear distortion effects
Enable compensation for surviving
linear distortion
What do we want to get out of our standard?
- It’s not about developing any “technology”
- It’s about taking mature technology that we know we have,
that we already use, and collaboratively making the most of it
Bottom line: “Unified Systems Engineering” approach
- don’t address “gaps” one at a time
- instead, make aggregate implementation decisions that facilitate
common solutions to multiple problems
Anticipated means of realizing these objectives:
- integrated CMA (Control, Monitoring & Alarm)
XML / secure XML over IP or SNMPv1/v3 (non-secure / secure)
- leverage existing standards & interfaces (i.e. IP, Ethernet)
- leverage industry-standard (IEEE) Ethernet Migration Plan
- leverage existing L-band architecture to migrate more efficiently
- convey waveforms using frequency bins at Digital IF interfaces vice time samples
- packetize at Layer 3 (IP)
- transport at Layer 2 (Ethernet), leveraging Ethernet Migration Plan
& continuous networking industry growth

13. Digital IF: Standards Process
Why IEEE?
Credibility, experience, affordability, technical oversight, indemnification umbrella
“Industry Connections”
“Incubation” stage - bring stakeholders together – with relevant IEEE support –under IEEE liability umbrella – up to 1 year
“Study Group”
Up to 6 months, IEEE sponsor
Advanced Corp Membership
Including “Government Agencies”
$3,500 to $10,000 / year
One membership, all standards
Present members include
DISA, Boeing
PAR & Working Group
Project Authorization Request
Min 3 Advanced Corporate Members
IEEE SA (Institute of Electrical and Electronics Engineers - Standards Association)
- strong reputation for worldwide technical standards
- reasonably priced
- launch based on technical merit as evaluated by (“sponsors” in) relevant technical societies
POC: Chris Vigil, IEEE-SA Membership Development, Piscataway NJ
Links
Process overview -
"Industry Connections“
- info
- online ICAID
(Industry Connections Activity Initiation Document)
Study Group Guidelines -
IEEE SA Membership
- Corp Svcs Overview:
- Rationale:
- Brochure:
- supplemental pro svcs:
- Application:
PAR (Project Authorization Request) Submittal
- FAQ
- content

14. Digital IF: Progress & Activity
MILCOM 2009 Concept Paper
Website
MILCOM 2010 CONOPS Paper
RDECOM CERDEC S&TCD FAST POTATO Participation
Visibility & Interest, Govt & Industry
PD-SCS POM wedge for FY 2013
Present Activity
Website updates
distribution list & e-newsletter
Establishing partnerships
IEEE Standards Association
We welcome collaborators !
More Information
sign up for updates
Work is not “development” per se. Work is in the standardization process; socialization, collaboration, synchronization, standardization, then COTS deployment
RDECOM CERDEC S&TCD
FAST = Future Advanced SATCOM Terminals
POTATO = Programs Other Than “ATO” (Advanced Technology Objectives)
near-term prototyping of
CBP = Configurable Baseband Processor
DLBC = Direct L-Band Converter
POC: Herald Beljour, RDECOM CERDEC S&TCD, APG MD
CHICKEN & EGG PROBLEM: Vendors don’t want to invest until Govt commits to spending money. But Govt wants a cooperative standard & COTS opportunity.
CHICKEN & EGG SOLUTION:
- Standardization initiative under 3rd party IEEE indemnification umbrella
- With aggressive Goverment leadership
- Welcoming close industry cooperation
RECOMMENDATIONS:
- Start sooner, not later
- Join our list
- Work Digital IF into your business plan (companies) or mission roadmap (Govt agencies)
- Participate in the Standards Process
- Start by browsing and signing up for updates