definition of reactive systems using the waveform description language

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Racal Research

A Thomson-CSF Racal Company

Definition of Reactive Systems using the Waveform Description Language

E.D.Willink, Racal Research Limited,[email protected],

http://www.rrl.co.uk/projects/wdl/wdl.html

SDR Forum and AFRL/IFGWaveform Development Environment Workshop,

1st November 2000,

UK Programmable Digital Radio (PDR) Phase 1,

Waveform Description Language (WDL) programme

(DERA contract CU009-0000002745)

Raytheon, Communication Systems Division, Fort Wayne, Indiana,

Racal, Racal Research Limited, England

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Introduction

WDL and Specifications

Examples (from FM3TR)

Architectural Mapping (JTRS)

Summary

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WDL Antecedents

W aveformD escriptionLanguage

B lockD iagram

Languages

R eactiveLanguages

S tateM achine

Languages

S pecificationLanguages

FunctionalLanguages

sem antics

types

constra ints

states

data flow

events

O bjectO riented

Languagesexpressions

classes

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Specification or Implementation

ImplementationHow it can be done

SpecificationWhat needs to be done

Waveform Description Language (WDL)Implementation practices re-applied in the

specification domain

One specification

Many alternate implementations

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WDL Products

W D L

H LA ,P to lem y,

...

S im ula tionE nvironm ents

E xecutionE nvironm ents

A pp lica tion ,P rocess,

C O R B A C om ponent,FP G A ,

A na logue hardware ,...

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Specification of Systems and Subsystems

subsystems exist at many scalestelecomms - international / national / regional / local / internal

equipment - cabinet / rack / module / board / component

CORBA components support two scalesinside

outside

WDLfully encapsulated

same approach at all scales

WDL specifies without implementing

WDL may be refined from a specification to an implementation

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Specification of Communication

High level systemssporadic control events

Low level systemsintensive calculation

‘continuous’ communication

WDLsporadic and continuous flows are supported

continuous and discrete time are interchangeable

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Complete specification (Low Level)

Amplifier - relatively easyvout = 10 * vin

In practice need constraintsfrequency < 1 GHz

load impedance 50 Ω ± 10%

third harmonic ...

WDLmathematical definition of the ideal behaviour

constraints to bound permitted behaviour

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Complete specification (High Level)

System specifications - very challenginglarge, unreadable

Informal specificationterse - omissions lead to ambiguities

verbose - duplications lead to contradictions

Formal specificationgood in principle

impractical for real applications

unapproachable for most practitioners

WDLpragmatic compromise

formalisable, modular, familiar, practical, acceptable

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Specification in WDLProgressive decomposition

systems - subsystems - components - building blocks

Single hierarchical perspectiveclear readable specification

removes ambiguities, avoids contradictions

Implementation in WDLProgressive refinement of specification

further decomposition

practical constraints

recomposition

Minimal refinementexecutable reference model

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WDL Transformations

W D LC om pile rs

S chem aticE d ito rs

D ecom position

R efinem entText

E d ito rs R efiner

C hecker

W D L P roducts, W aveform B und le

W D L P rogram

W D L S pecifica tion

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WDLRefinement

W D L P rogram

S ponsor

A bstract S pecifica tionlayerscodersm odula tors

Im plem enter

A ctua l S pecifica tiona lgorithm sparam etersb it-tru th

R eference M ode lprecis ionsacqu is ition a lgorithm s

S ystem D esignfilte r characteristicsacqu is ition a lgorithm sm in im um precis ions

S ystem C onfigura tionfilte r characteristicsdecim ation ra tios

H ardware M app ingpartition inglib rary m atch ing

C om ponent C onfigura tionparam eterisa tionactua l p recis ionsb it-tru thW D L S pecifica tion

R eference M ode l P roduct

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Refinement

Abstract WDL specification (unimplementable)

Waveform sponsor refines to supporta reference model

System designers refine to supporthardware partitioning

analogue/digital partitioning

concrete filter designs

specific acquisition strategies

apportion implementation loss budgets

Implementers refine toexploit pre-existing object libraries

compensate for compiler limitations

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Hierarchical decomposition

Entitymodule of specified behaviour

not necessarily an implementation object

Messageuser defined data types (and array shapes)

four scheduling flow types

Hierarchical Diagramsmessage flow diagrams

statecharts

Leaf specificationmathematical definition

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(UML) Statechart

WDL extension to UML:state behaviour

may be a message flow

StateChartEntityeventguard

out State1

State2

event[guard]/out(...)

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Message Flow Diagram

WDL Message Flow Diagrameach arc has defined data and flow type, connecting at ports

each entity is self-scheduling - rendezvous of relevant ports

external ports to define hierarchy

cf. UML Collaboration diagramexternal scheduling, connection points have no semantics

M essageFlowEntityin1in2

out

Entity2in outin1

outin2

Entity1in1in2

out

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FM3TR

Future Multi-band Multi-waveform Modular Tactical Radio

FM3TR Technical Working Group (Fr-Ge-UK-US)

30 - 400 MHz

25 kHz channels

25 kbits CPFSK

250 - 2000 hops/second

16 kbits transparent (voice)

9.6 kbits coded (data)

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FM3TR Protocol Layers

Application

Presentation

Session

Transport

Network

Data Link

Physical

OSI layers

Hcinwk

d lc

m ac

ph l

vo ice_ in

data_ in

data_out

antennavo ice_out

M actx_ from _dlchcirx_ from _phlcarrie r_detect

rx_ to_d lc

tx_ to_ph l

Phltxhci

vo ice_ in

rxcarrie r_detect

antennavo ice_out

Dlcin_ from _nwkhcirx_ from _m ac

out_ to_nwk

tx_ to_m ac

Nwkdata_ inhciin_ from _dlc

data_out

out_ to_d lc

Fm 3trdata_ invo ice_ in

data_outvo ice_out

antenna

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FM3TR Physical Layer

Phltxhcivo ice_ in

rxcarrie r_detect

vo ice_outantenna

TransSectrans_sec

Tx

intx_ inc

out

Rx

in

rx_ inccrc_ inc

out

Pttvo ice_ inreset

vo ice_outantenna

carrie r_detect

rx

vo ice_out

hci

tx

vo ice_ in

Radiorf_ freqrf_out

antennarf_ in

Cdt_cd_ont_cd_offcarrie r

de tectHci

hcitx_ incrx_ inccrc_ inc

t_cd_ont_cd_off

config

Fsmconfigtxtrans_sec

vo ice_ inrf_ in

carrie rrx

vo ice_out

rf_ freqrf_outreset

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FM3TR Physical

Layer State

Machine

V O IC E _TX

rf_outrf_ freq

configvo ice_ intran_sec carrie r_detect

TxM odulatoram plitudephase_changerf_ freq_ in

rf_outrf_ freq_out

carrie r

VoiceTxFsmconfigvo icetran_sec

am plitudephase_change

rf_ freq

exit

exit

vo ice_ in [p tt]

tx

D A TA _TX

rf_outrf_ freqpacket

tran_sec carrie r_detect


rf_outrf_ freq_out

carrie r

Sinkin

config

vo ice_ in

DataTxFsmconfigdatatran_sec


rf_ freq

R Xentry / reset()

rf_ freqrf_out

rxrf_ in

tran_sec

vo ice_outcarrie r_detect

config

vo ice_ inSink

in

RxFsmconfigrf_ inrf_ freq

rxvo ice

carrie rRxM odulator

tran_sec rf_outrf_ freq

V O IC E _TX

rf_outrf_ freq

configvo ice_ intran_sec carrie r_detect


rf_outrf_ freq_out

carrie r

VoiceTxFsmconfigvo icetran_sec


rf_ freq

exit

exit

vo ice_ in [p tt]

tx

D A TA _TX

rf_outrf_ freqpacket

tran_sec carrie r_detect


rf_outrf_ freq_out

carrie r

Sinkin

config

vo ice_ in

DataTxFsmconfigdatatran_sec


rf_ freq

R Xentry / reset()

rf_ freqrf_out

rxrf_ in

tran_sec

vo ice_outcarrie r_detect

config

vo ice_ inSink

in

RxFsmconfigrf_ inrf_ freq

rxvo ice

carrie rRxM odulator

tran_sec rf_outrf_ freq

Fsmtxvo ice_ inrf_ inconfigtran_sec

rxcarrie rrf_out

rf_ freqvo ice_out

reset

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Hop Modulator

IN FO R M A TIO N

m odula tionconfighop

In foM odulatorconfighop

m odula tion

TU N IN G _T IM E


G uardM odulatorconfighop

m odula tion

R IS E _T IM E


RiseM odulatorconfighop

m odula tion

FA LL_T IM E


FallM odulatorconfighop

m odula tion

afte r(config .tun ing_tim e)

a fte r(config .rise_tim e)

exit

a fte r(config .fa ll_ tim e)

tuningtim e

risetim e

falltim e

inform ationtim e

HopM odulatorhopconfig

m odula tion

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Hop Rise Time

constraint: shift.out = 0;

constraint: freq.out = hop.frequency;

constraint: amp.out = range {

minimum 0; value 0.5 * (1 - cos(2*pi*t/config.rise_time)); maximum 1; };

RiseM odulatorconfighop

m odula tion

m odula tion

F(t)

am p

out

Constructoram plitudefrequency_sh iftfrequency

m odula tionConstant

sh ift

ou t

Constant

freq

out

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Language for specification

need expressions forconfiguration constraints, state machine guards

need statements forstate machine actions

need types formessages

need a languageimplementation languages do not specify

specification languages are unapproachable

specification languages have unhelpful focus

new language is new

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Specification

entity Subtractor{in minuend;in subtrahend;out difference;response minuend subtrahend // Whenever a rendezvous of{ // minuend and subtrahend

existsspecification { // receive minuend and subtrahenddifference(minuend - subtrahend); // subtract values

}; // send to difference};

};

Polymorphictype, shape, flow, language

Subtractorm inuendsubtrahend

d iffe rence

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Hardware MappingDedicated hardware

direct compilationone ‘executable’ per ‘execution unit’

General Purpose ‘Virtual’ hardware - software radioCORBA components

software processes

HLA entities

identify components and messages

indirect compilationone executable per component per platform

one interface declaration per message

configuration profiles per application

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FM3TR Layers

asJTRS

Componentsand

MessagesFm 3trH ci

Fm 3trM odem

Fm 3trL ink

Fm 3trN etworkHci

nwk

d lc

m ac

ph l

vo ice_ in

data_ in data_out

antenna

vo ice_out

M actx_ from _dlchcirx_ from _phlcarrie r_detect

rx_ to_d lc

tx_to_ph l

Phltxhci

vo ice_ in

rxcarrie r_detect

antennavo ice_out

Dlcin_ from _nwkhcirx_ from _m ac

out_ to_nwk

tx_to_m ac

Nwkdata_ inhciin_ from _dlc

data_out

out_ to_d lc

D outD in

D toM

N toD

V outV in

H toP

H toM

H toD

H toN

D toN

M toD

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JTRS Mapping for FM3TR

C P UD S P D S P C P U

B oard S upport P ackageN etwork P ro toco l S tacks

P osix R TO S D S P E xecutive

B lackIN FO S E C

A dapter

R edIN FO S E CA dapter

IN FO S E C A lgorithm


P osix R TO S

C ++ C O R B AO R B andS ervices

C F C oreD om ainM anagerD eviceM anager

F ile S ervicesLoggerT im er

D evice

B oard S upport P ackageD S P E xecutive

M odem B lack C ontro l P rocessor R ed C ontro l P rocessorIN FO S E C


P osix R TO S

C ++ C O R B AO R B andS ervices

C F C oreD om ainM anagerD eviceM anager

F ile S ervicesLoggerT im er

D evice

Fm 3trH ci

Fm 3trN etwork

Fm 3trM odem .P hl.T ranS ec Fm 3trL inkFm 3trM odem .M acFm 3trM odem .P hl.nonTranS ec

Fm 3trM odem

B lack P rocessor C ard R ed P rocessor C ard

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WDL & JTRS Summary

WDLefficient methodology for developing many waveforms

provides unambiguous specification

provides portable implementation

JTRS a common radio architecture for waveform development

WDL with JTRSspecification and implementation via portable components

WDL without JTRSspecification and implementation via direct compilation

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Summary

WDL specifies a determinate behaviour

Decomposition to manageable sub-specifications

Refinement to support a reference model

Refinement to support product implementations

Polymorphism to exploit generic libraries

Realistic scheduling models

Type-oriented code generation for flexibility

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Status

Phase 1Initial consideration of language concepts

Example decomposition of FM3TR (1 month)clearer

many anomalies reported back

FutureBetter quality specifications

sponsor provides reference model

Semi-automated code generationmonths rather than years

definition of reactive systems using the waveform description language

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