SimPhonics, Inc.

Networked Audio Networked Audio Using VUsing V+ + and and VCommVComm

SimPhonics, Inc.

Overview

What is VComm? Networked audio component of V+ Uses DIS, HLA, and VoIP protocols

Connects simulators via network

Simulate radios over networkProvide Intercoms, Radio simulation, etc.

Interoperate with ASTi and others

SimPhonics, Inc.

Overview

Can be used with any Windows XP Need sound and network device (card) Works on laptops, desktops, etc. Unlimited number of radios and operation

Not credit based

Add-on to V+Sold separately

SimPhonics, Inc.

Overview

VComm is networked audio For local audio use SMx or other means VComm could be used for local communications

Inefficient since it uses network sockets

VComm and SMx can be used togetherSMx uses virtual WI and WO, well suited for VComm

SimPhonics, Inc.

DIS/HLA PrimerDIS/HLA Primer

SimPhonics, Inc.

DIS/HLA Primer

DIS– Distributed Interactive Simulation

HLA– High Level Architecture

SimPhonics, Inc.

DIS/HLA Primer

DIS in wide use– Military exercises

Virtual flag– Several hundred participants– SimPhonics systems play prominent role– Interoperable with ASTi, Plexus and emDee

SimPhonics, Inc.

DIS/HLA Primer

DIS– IEEE 1278.1a standard

Distributed network for simulation interoperability DIS in wide use HLA less prominent but newer

SimPhonics, Inc.

DIS/HLA Primer

DIS versions– IEEE 1278.1-1995

First IEEE Standard

– IEEE 1278.1a-1998Second IEEE Standard

– 1278.1a-200x (Draft 13)Under developmentSimPhonics leading Radio Tiger Team EffortSISO PDG

SimPhonics, Inc.

DIS/HLA Primer

DIS versions– IEEE 1278.1a-1998

Latest IEEE StandardAdded Intercom PDUs (ICS)ICS PDUs are not being used

– 1278.1a-200xImproving plug and play capability for radiosEncourage vendors to interoperateFix bad sections in standard

SimPhonics, Inc.

DIS/HLA PrimerDIS protocol based on UDP/IP– All Communication is via PDUs

A PDU is an Ethernet packet PDU Families

Entity Information/InteractionWarfareLogisticsSimulation ManagementEmission RegenerationRadio CommunicationsEntity ManagementMinefieldSynthetic EnvironmentSimulation Management with ReliabilityInformation EperationsLive Entity

SimPhonics, Inc.

DIS/HLA Primer

Relevant PDUs to VComm– Entity State

Used only for entity attach (more later…)This means that all entity PDUs must be inspected if entity attach is being used

– Radio Communication PDUsTransmitterSignalReceiverIntercom signal (IEEE 1278.1a 1998 only)Intercom control (IEEE 1278.1a 1998 only)

SimPhonics, Inc.

DIS/HLA Primer

Radio Communication PDUsTransmitter

– Convey information about a simulated transmitter, on/off, type, secure equipment, etc.

Signal– Carries actual digitized audio data (voice)

Receiver– Conveys information about simulated receivers. This is

not a widely used PDU, although SimPhonics does implement this PDU (possibly the only vendor).

SimPhonics, Inc.

Transmitter and Signal PDUs

SimPhonics, Inc.

DIS/HLA Primer

HLA Publish and subscribe mechanism

– Much more efficient– Single process called RTi handles all interactions– At one time in the past, all DOD sites were mandated to

be HLA compatible…(did not happen) Difficult to setup and use

– Low interoperability in industry FOM

– Federate Object Model– All applications must use same FOM– Most popular is RPR FOM 1.0

SimPhonics, Inc.

DIS/HLA Primer

HLA VersionsOriginal version known as HLA 1.3

– Developed by DMSO – public distribution– Has since been handed to industry and is no longer avail.

Current IEEE 1516 standard– HLA 1.3 still Prominent

SimPhonics, Inc.

How to use VComm How to use VComm with Vwith V++

SimPhonics, Inc.

VComm DIS Radios

Define RequirementsInteroperability requirementsVoice QualityNetworking Issues

Configure VCommCreate .VNE file

Build V+ ApplicationReuse existing, or create new model

Monitor SystemDebug, resolution of problems

SimPhonics, Inc.

Interoperability Issues

Interoperability requirements If interaction with other vendor radios,

– Determine their needsSample RateCompression schemeSignal PDU lengthModel Fidelity – frequency match

Otherwise, no worries

SimPhonics, Inc.

Voice Quality

Sample RateBest voice quality when:

16,000Hz sample rateNo compression scheme, (PCM)Longer signal PDU lengths (1048)

Only works when you have this freedomNot interoperatingNetwork Bandwidth is available

8000Hz most commonMeets basic DIS requirementDefault VComm setting

SimPhonics, Inc.

Voice QualityCompression Schemes

1 = mu-law, 2:1 2 = CVSD, 16:1 (MIL STD 188) 3 = ADPCM, 4:1 4 = 16-bit PCM (Big Endian), 1:1 5 = 8-bit Linear PCM, 1:1 6 = VQ, variable comp., (not supported in VComm) 7 = CVSD CCTT, 16:1 8 = 1.625-bit GSM0, variable comp., (currently in devel.) 9 = 0.7-bit GSM0, variable comp., (currently in devel.) 100 = 16-bit PCM (Little Endian), 1:1

Only mu-law required to be compliant with (current) DIS standard

SimPhonics, Inc.

Voice Quality

Signal PDU length– Any length will work with VComm, but

No Specification Requirement VComm and ASTi use 480

– Best to use other vendor’s settings

SimPhonics, Inc.

Network Issues

VComm Network Topology Broadcast

– Simple to configure, inefficient

Unicast– Point to Point

Multicast– Difficult to Configure, efficient, becoming standard

method of DIS networking

SimPhonics, Inc.

ConfigurationNetwork Topology

SimPhonics, Inc.

ConfigurationDefault port is 3000

SimPhonics, Inc.

Configuration

Specification version should not matter, but, some exercise filters require certain versions…

SimPhonics, Inc.

ConfigurationHLA Setup

SimPhonics, Inc.

ConfigurationTerrain Server Setup

SimPhonics, Inc.

Build V+ App

Select existing design– Explore

C:\Program Files\VPLus\VPLus Samples\VComm– “VComm Radio.des”– Should not have to change anything

SimPhonics, Inc.

Build V+ App

Push-To-Talk

Frequency

SimPhonics, Inc.

Build V+ App

Exercise ID

Antenna Location

SimPhonics, Inc.

DIS IDs

If IDs are left at zero– VComm generates an ID based on IP address

(e.g., 192.168.100.33 generates an ID of 100/33/1/x

Otherwise, you must specify ID’s– Difficult configuration management

SimPhonics, Inc.

Setting Compression Scheme

Compression Scheme

SimPhonics, Inc.

Antenna Location

Three ways to set Antenna location

Hard code the X,Y,Z inputs with constants Connect inputs to another computer (Host) Attach the radio to an existing network entity

SimPhonics, Inc.

Antenna Location

Entity Attach Allows VComm to attach to an existing entity on network Must know the entity ID Use Object 2017

SimPhonics, Inc.

DIS/HLA Setup

SimPhonics, Inc.

DIS/HLA Setup

Each VComm radio is independent Simultaneous use of DIS/HLA “Send To Network” static data determines DIS/HLA network selection Can use both! “Send To Network” Settings:

0 - off (no packets will be sent) 1 - DIS 8 - HLA 9 - Both DIS and HLA

SimPhonics, Inc.

Network Monitoring –VComm Monitor

SimPhonics, Inc.

Instrumentation –Perfmon.exe

SimPhonics, Inc.

Instrumentation (Perfmon.exe)

Performance monitors Incoming PDUs Outgoing PDUs Dropped TX packets Incoming Transmitter PDUs Incoming Signal PDUs Incoming Entity State PDUs Incoming ICS Control PDUs Incoming ICS Signal PDUs Number of Radios in Exercise

SimPhonics, Inc.

Inside VCommInside VComm

SimPhonics, Inc.

Signal Processing Models

SimPhonics, Inc.

Path Loss Model

Path loss is several models Free space propagation Loss WGS84 earth model LOS Refraction Terrain surface type Fresnel effects Multi-path signal fading Terrain database

SimPhonics, Inc.

Propagation Loss Model

Signal Power at Receiver vs. Distance from TransmitterTransmitter Power = 5 Watts

-90.0

-80.0

-70.0

-60.0

-50.0

-40.0

-30.0

-20.0

-10.0

0.00 100 200 300 400 500 600

Distance (km)

Sign

al P

ower

(dB

)

30 MHz

60 MHz

90 MHz

120 MHz

150 MHz

180 MHz

210 MHz

240 MHz

270 MHz

300 MHz

330 MHz

360 MHz

390 MHz

SimPhonics, Inc.

Smooth Earth Model

Line-Of-Sight WGS84 Earth Model LOS Diffraction Effects Terrain

SimPhonics, Inc.

Fresnel Effects Model

Fresnel zone 1 Up to 60 dBm before LOS interference

SimPhonics, Inc.

Tuner Model

Definition (Bandwidth)

SimPhonics, Inc.

Tuner ModelVComm Tuner Model

Uses Gaussian functionsBand pass response if Specific to radio

SimPhonics, Inc.

Noise Model

Radio noise Thermal noise (KTB Noise)

– Function of Bandwidth– -131 dBm at 25,000 Hz

Atmospheric noise– Based on several types of noise– Includes Galactic and Man-made– Zero below 100,000 Hz (ICS frequencies)

SimPhonics, Inc.

Noise Model

SimPhonics, Inc.

Audio Filtering

Audio filtering for realism Real radios band pass the audio

300 to 3,000 Hz

Sounds distinctly like a radio VComm Radio Audio Emulation Filter (object 2055) provides this capability

SimPhonics, Inc.

300Hz to 3000Hz Band-pass FilterUnfiltered DIS Radio

(All Competitors)

Filtered DIS Radio

(Realistic Model)

Click on Icons to Hear Difference

SimPhonics, Inc.

Other special audible effects

“Squelch tail” Heard at end of incoming transmission

Function of AGC, S/N level, etc.

Radio power on and power off sounds Radio specific

Secure effects System specific effects

Test Tones, etc.

SimPhonics, Inc.

Important Issues to Important Issues to RememberRemember

SimPhonics, Inc.

Coordinate Systems

Geodetic Geocentric (DIS)

LAT, LONG, ALT X,Y,Z

SimPhonics, Inc.

Coordinate Systems

DIS uses Geocentric Object to convert Geodetic to Geocentric Note that 0,0,0 Geocentric is the center of the earth and a de-facto DIS standard for non-propagation loss radio.

SimPhonics, Inc.

New Style (V8.0) VComm Radios

SimPhonics, Inc.

Old Style VComm Radios

SimPhonics, Inc.

Device versus ChannelBe careful when dealing with legacy radios

Devices are two channels of left and rightChannels are independent streams

Device Channel

1 Left 1

1 Right 2

2 Left 3

2 Right 4

Etc…

SimPhonics, Inc.

Antenna Location

De-facto standardx,y,z = 0,0,0 means no propagation loss and is most widely usedAny other location, and propagation loss model is in effect