Portable -20W Vehicular-100W Base-Station 400W & Higher · © 2009 by Elbit Systems | Elbit Systems...

Implementation ChallengesStandards in Tactical HFStandards in Tactical HF

Yehuda EderSenior Director, HF R&DLong Range Communication division

© 2009 by Elbit Systems | Elbit Systems Proprietary

Why HF?

Adv

anta

ge


HF Applications

1000km

10,000km2000km

Portable -20W Vehicular-100W Base-Station 400W & Higher


Standards & Protocols


Standards for HF-Data Transmission Systems

MIL-STD: Military Standards of DoD (US)MIL-STD-188-110B

MIL-STD-188-141B

STANAG: NATO STANdardization AGreementSTANAG 4285

STANAG 4538

STANAG 5066

HF HouseCollection of actual standards for HF communications


2GARQ

HF House

STANAG 5066 STANAG 4538

EPMLSU

ARQ

EPMWAVEFORMS

3GALE

2GALE

8FS

K

S 4285, S 4529, S 4539, MS110, etc

Traffic Waveforms

Interface toHigher ISO Layers

Network LayerLink Layer

Physical Layer

Abbreviation: 5xxxx: STANAG xxxx MSxxxx: MIL-STD-188XXXX 2G: second Generation 3G: third Generation

HF standards are described in the “HF House”:Comprise fixed frequency and frequency hoppingUtilize techniques for setting up and maintaining

skywave channelsHF is proving useful in current operationsMany standards offered by industry

5066

Bur

st W

F


Main Standards2G ALE: MIL-STD-188-141B

3G ALE: STANAG 4539

Performance ComparisonFast link setup (from HFIA’s last meeting)

Auto Link Establishment

3G ALE – Improved the link setup time but tactical operations requireeven faster links

3G ALE2G ALECharacteristic

8.4s (Average values )15.3s -3 character call signLink Time

-8dB(3kHz BW)(4dB PAPR)0dB(3kHz BW)(0dB PAPR)Link Robustness

8-PSK – 2400 sym/s8-FSK – 125 sym/sWaveform

Synchronous Asynchronous Supported

AsynchronousMain mode of Operation

Y – Widely usedY – Not widely usedLink Protection

LQA & Traffic MonitorLQA & Traffic MonitorChannel Evaluation


Proprietary protocols

ALE Systems from early 80s

Collins Selscan

Harris Autolink

Sunair Scancall

Tadiran AutoCall

Most of the proprietary protocols are faster then 2G and 3G ALE

Auto Link Establishment


Case Study: AutoCall

SCANNINGScans the set of frequencies

Monitors the traffic on each frequency

Monitors the local noise level on the non-active frequencies

Registers the signal strength

Registers the software BER

Updates the radio set with grade for multiple stations and frequencies


Case Study: Autocall (Cont.)

Channel frequency assignment parameters:Traffic type (Voice or Data)

Link quality measured at both ends

Information validity management of the “link quality”

Link busy Information (traffic on the available frequencies)

The decision is based to the Link quality measured during the “current” link establishment process

Requirements for link establishment:Link quality is higher than a preset minimum quality level

If the minimum required quality is not available the Autocall algorithm chooses the best available frequency

The final establishment of the link is made by means of a “Handshaking”protocol

The result: Linking in less than 4 seconds!


Large Networks Management


Multi-Net operation

Enhanced MIL-STD188-141B

Scanning multiple NETs simultaneously

Enhanced System configuration

NET1

NET2

NET3

Multi net radioscanning Net1, Net2, Net3


Large networks challenges

Operational environment challengesAgencies need to managing large networks , multi networks ,channels and addresses

The need to communicate between agencies in crisis situations

ALE core

•FEMA net data base:•Index

•Station name•ALE Address

•Channels , frequencies •Setting parameters

•NG net data base:•Index



•DEA net data base:•Index



Request for link

Linking with minimum LQA or bidirectional LQA updated

“Un limited” DB

•User NET •Station name•ALE Address•Channels , frequencies •Setting parameters•Sounding


Adaptive Multiple Networking

ALE Data Base Managing from external ALE core

Keeping - JITC Certification per MIL-STD188-141B

Interoperable with all ALE - MIL-STD188-141B networking system

Fast Dialing

14


Adaptive Multiple Networking

ALE Index Linking in minimum LQA to save sounding

Linking on best CH with Bidirectional LQA update

Dialing (index) feature

15


Data over HF


Data – WF in PRC configurations

64 QAM over linear with high efficiency amplifier

Radio performance required -24dbc

Modem WF for 64 QAM required above 33db SNR

-24dbc and 33db SNR can not works together ,

linearization techniques are needed

Advances in WF’s and ProtocolsBut radio performance still lags behind…

P A

DCP.S.

LPF

Harmonicfilter

Att.

PTX=500 Watt

Envelope

LPF28 / 48 VDC

110 VAC (option)

PIN =1 Watt

Phase modulated RF

RF modulated-to-Polar

Cartesian Linearization(complex closed loop)

Signal ProcessingUnit

DC feedback


PRC/VRC Data applications

Data base management – ALE , FH ,5066 ..

Many Self Addresses with different lengths

E-mail addresses management

“other” addresses management

Real life: In most common implementations, due to the distributed DB’s, PC & Radio form unique pair logistic nightmare…

Radio


STANAG 4444 and data applications

Mode of operation Linking

Activating the Data mode

– STANAG 5066 is running on the tactical PC

– Switching to FH – now what ? The frame should be adapted to 5066 packets

The problem MPDATAITAGCHTT

32n x symbols1216# of Symbols

42/4/8444PSK Modulation Order

Duration

n x symbols – needs to be adapted to 5066 rates with FEC and interleaverdelays Hop duration adaptation will be required


Summary


Summary

Faster Communication Protocol is required

Managing large networks – processes is recommended to define

Radio performance should be updated

Data Base addressing definition is required

FH – Frames adaptation to accurate rate is required

Portable -20W Vehicular-100W Base-Station 400W & Higher · © 2009 by Elbit Systems | Elbit Systems...

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