TETRA The pan-European trunking standard

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TETRA The pan-European trunking standard
TErrestrial Trunked RAdio
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?? e??a? t? TETRA?

• ??? ????pa??? ???t?p? ??a ?ad??ep????????e?
• ?a????st??e ap? t? ETSI (1995, 22 ???e?)
• ?????? ??f?a?? ?pa??e?µat??? S?st?µa ????t??
  ?p??????????
• ?a???e? ????? ßa?µ? asf??e?a? ?a? a???p?st?a?
• ?p?st????eta? ap? p?????? ?atas?e?ast??
• Ta ???s?µ?p????e? ap? t?? pe??ss?te?e? ????pa????
  ???e?

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?? e??a? t? ETSI?

• ????pa??? ??st?t??t? ???ep????????a??? p??t?p??
• ?a???e? ???ep????????a?? p??t?pa ??a t?? ???e?
  t?? ???µ???? ????p?? ?a? t?? ???p??
  d?t???e???pa???? ???e?
• ?a p??t?pa t?? ETSI e??a? p??a??et??? ??a t??
  ???e? µ???

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?? ??epaf?? t?? TETRA

• AIR IF ?s??µat? d?epaf?
• TEI??epaf? ?e?µat???? s?s?e??? (a??pt???
  efa?µ???? data)
• ISI ??as??des? d??t??? TETRA
• DMO ?pe??e?a? s??des? te?µat????

Controller
Gateway
BS
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TETRA Connectivity
Public Data Network
LAN/WAN
Internet
2BD 30BD
ISDN
ISI
TEI
PSTN
PABX
Conventional Base Stations
Command Control Systems
Trunking Networks
Conventional PMR Networks
Customer Care Billing Systems
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TETRA Voice Data Services
Man-machine Interface
Man-machine Interface
TELESERVICES
Terminal Interface
Terminal Interface
BEARER SERVICES
Mobile Termination
Network Termination
Terminal Equipment
Terminal Equipment
Tetra Network
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??epaf?? TETRA
1. System air interface 2. Direct mode air
interface 3. Man-machine interface 4. Radio data
peripheral interface 5. Local dispatcher 6. Gatewa
y to external network 7. Remote line connected
terminal 8. Inter system interface 9. Network
management interface

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3
1
Base Station
Base Station
Base Station
Network Manager
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Infrastructure
Inf.
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Inter System Interface

Gateway
Controller
Local Dispatcher
System Infrastructure
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Remote Line Dispatcher
PSTN/ISDN PABX/PDN
ISDN
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??a ?a?a?t???st??? t?? TETRA

• ?????? aµf?d??µ? ?e?t?????a
• ?a?t?????? µet?d?s? f???? ?a? ded?µ???? µe µ?a
  s??des?
• ???pt????f?s? d?? ep?p?d??
• ?as???? ep?p?d?? st?? (as??µat? d?epaf?)
• ???pt????f?s? ap???? s???? (end-to-end
  encryption) e?d??? ??a ???ste? t?? t?µ?a ??µ?s?a?
  ?sf??e?a?
• ?e?t?????a ?????t?? ??a???? (open channel mode)
• ?e?t?????a ?a?a???????s?? (dual-watch mode)
• ?????? ???µ?? µet?d?s?? ded?µ????

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?as???? ?p??es?e? TETRA
F???t???? ?p??es?e? S?????? ???s? ?µad???
???s? ?µad??? ???s? µe ep?ßeßa??s? ???s?
t?p?? Broadcast S?????? ? ???pt???af?µ???
s??d???e?? ?p??es?e? ?ed?µ????????? p??stas?a
µ???? 28,8 kBits/s ?e p??stas?a µ???? 19,2
kBits/s ?e µeta???? ?????µat?? (Circuit
Switched) ?e µeta???? ?a??t?? (Packet
Switched)
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TETRA Voice Data Services

• Bearer services
• Circuit mode data 7.2/14.4/21.6/28.8 kbit/s
• Circuit mode protected data 4.8/9.6/14.4/19.2
  kbit/s
• Circuit mode heavily protected data
  2.4/4.8/7.2/9.6 kbit/s
• Connection oriented packet data
• Connectionless packet data
• Teleservices
• Speech for individual call, group call,
  acknowledged group call, broadcast call
• Status and short data messages

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Essential Supplementary Services
Call Authorised by Dispatcher
Dispatcher verifies call request before allowing
call to proceed.
Area Selection
Defined areas of operation for users. Can be
redefined on a call by call basis.
Access Priority
Radio Unit uplink access prioritisation during
congested periods.
Priority Call
Access to network resources can be prioritised
Late Entry
Latecomers may join a call in progress.
Pre-emptive Priority Call
This call has the highest uplink priority and
highest priority access to network resources. If
system is busy the lowest priority communication
will be dropped to allow this call to continue.
Equivalent to an "Emergency Call" in PMR terms.
Discrete Listening
Authorised RU may monitor a communication without
being identified.
Ambience Listening
Dispatcher may turn on the transmitter of a RU
without any indication being provided on RU. Can
be used in hijack situations to listen what is
happening in the car.
Dynamic Group Number Assignment
Allows the dispatcher to program new group
numbers into the RUs over the air. Can also be
used to group participants in an ongoing call.
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Optional Supplementary Services
Calling Line Identification Present
Displays the unit ID of calling party
Connected Line Identification Present
Displays the unit ID of the called party
Calling/Connected Line Identification Restriction
Either party may prevent display of unit ID
Call Report
Displays calling party ID on a busy RU
Talking Party Identification
RU automatically identifies itself whilst in a
group call
Call Forward Unconditional
Allows an RU to forward all calls to another RU
Call Forward on Subscriber Busy
Allows an RU to forward calls if RU busy
Call Forward on Subscriber Not Reachable
Allows an RU to forward calls when out of service
or switched off
Call Forward on No Reply
Allows an RU to forward all unanswered calls
List Search Call
Incoming call will sequence through a user
defined list until call is answered
Short Number Addressing
Short number dialling
Call Waiting
Notification of an incoming call to a busy RU
Call Hold
Allows user to interrupt existing call and
re-establish when required
Call Completion Busy Subscriber
Incoming call will wait until subscriber is free
before calling back
Call Completion No Reply
Incoming call will wait until subscriber has made
a call before calling back
Transfer of Control
Initiator of a group call can transfer ownership
to another party
Include Call
Ability to include an RU in an existing call
Advice of charge
Call charge information at start, during or end
of call
Call Barring
Ability to bar a call from/to a user defined list
Call Retention
Ability to prevent call being pre-empted
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???ste? s?st?µ?t?? TETRA
?p??e???se?? ?????? Of??e?a? ?p????e?a ?a?
?st???µ?a ????t???? pe?????? ?d??t????
?ta??e?e? µe µe???? st??? ???µ?t??
Network operators
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??µ?a? ??µ?s?a? ??e?a? ?a? ?sf??e?a?

• ?st???µ?a (?e???e?a,, ????a?a ?.?.p.)
• St?at??
• ????sßest??? ?a? ???a??sµ?? ???s?s??
• ???te? ????e?e? ?a? ?at????? ?p??es?e? ??ta?t??
  a??????

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??p??? d??t?? TETRA ??a t?? ??µ?a ??µ?s?a?
?sf??e?a?
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?p??es?e? TETRA ??a t?? ??µ?a ??µ?s?a? ?sf??e?a?

• Service
• Dispatcher
• Clear and ciphered voice
• PABX/PSTN manual access
• PABX/PSTN automatic access
• Image transmission
• Host database access
• Radio Local Network (RLN)
• Computer Aided Despatching

Dual watch
R.L.N.
G.P.S. dead Reckoning

TETRA Network
Automatic

G.P.S. dead Reckoning
PABX PSTN
T
HOST
Digital Map
PABX PSTN
T
G.P.S. dead Reckoning

Manual
Command Control Centre
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TETRA NETWORK

• Resources management
• and positioning

DATA BANKS
EVENT
DECISION
INTERVENTION
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????????S??S ?????S OF?????S

• ???t?a ?a???? ?????e?a? (?????, ?et???a??,
  ??e?t???? ?????e?a ?.?.)
• ?etaf???? (??a??a, St???? ???µ?t?? ?.?.)

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?fa?µ???? pe?at??

• Operational Services Voice
• Radio Communications with remote areas
  (extraction wells, booster stations, etc) and
  Mobile Operators (maintenance and emergency
  squads, etc).
• Telephone Communications between peripheral
  offices, headquarters, and PSTN.
• Operational Services Data
• Efficient Informatic Networks for transmission of
  data regarding Companys activities (ex Energy
  Production, Treatment Processes, etc.)
• Administration and Management.
• Computer applications for production forecast and
  accounting.
• On - line tasking and job control.

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?fa?µ???? (s????e?a)

• Operational Services Remote Control
• Radio Remote Control of Gas Oil fields, Booster
  Stations, Oil Treatment Plants, Power
  Substations, Railways Stations, etc.
• Telesurveillance for Remote Sites to prevent
  fires, intrusions and terrorist attacks.
• Remote metering.
• Commercial Services (Service Providing)
• Voice - Mobile Communications (Radio Telephony)
• - Fixed Communications (PABX Network)
• Data - Electronic Payment
• - Others (fax facilities ...)

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?p??es?e? ???t??? ??????? ?p?st?????µe?e? ap? t?
TETRA
Data acquisition (Gateway towards external Data
Banks).
GPS SATELLITE
Satellite Antenna
models and statistics
OPERATION MANAGEMENT AND SUPERVISION
EXTERNAL DATA BANK
Data transfer toward operative locations
Data
Vehicles localisation
INTERVENTION MANAGEMENT
TYPE OF ALARM
BSC/BCF
GPS Satellite Antenna
Voice
Communications between centre and periphery.
On-board sub-system
TETRA NETWORK (voice/data)
CONTROL CENTRE
RADIO OPERATORS
EVENT
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S?st?µa TETRA ???eep?t???s?

• Remote Video Control of critical areas.
• Anti-intrusion Systems.
• Fire-alarm Systems.
• Access Control.

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TETRA SystemTelesurveillance example CCTV
network
M Optical modulator D Optical demodulator MI
Management interface CSM Central system
management
Remote Area
Videocameras
M
M
M
M
D
CENTER
Local Control
CSM
Radio TETRA Network
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???????e??t? s?st?µa TETRA
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???????e??t? s?st?µa TETRA
System Controller
System Controller
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???e? S????t?t?? st?? ????p?

• NATO military use

• MoU on common frequency allocation has been
  signed by most European countries
• Non-NATO countries may allocate military band for
  civil use (plans for commercial use atleast in
  Austria and Finland)
• Plans for civil TETRA networks in 410-430 MHz
  band in many European countries (already 2
  licences in UK)
• Other planned frequencies 450-470 and 870-876 /
  915-921 MHz

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?e????? ?a?a?t???st??? TETRA
Channel Spacing 25 kHz Modulation PI/4
DQPSK Channel Data Rate 36 kBits/s Speech Code
Rate appr. 4,8 kBits/s Access
Method FDMA/TDMA, 4 Timeslots User Data
Rate 7,2 kBits/s per Timeslot Variable Data
Rate 2,4 up to 28,8 kBits/s
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TDMA Timeslot Channels
"Downlink" Frequency
1
2
3
4
"Uplink" Frequency
1
2
3
4
1
2
3
4
1
2
3
4
Time

• Channel Timeslot sequence (Frequency)
• 4 Channels per RF carrier occupying 25 kHz
• Channels may be used for control or traffic

Base Station
Downlink
Uplink
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TETRA TDMA

• speech calls use one channel
• data calls can use up to 4 channels (multi-slot
  data)

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?e????? ?a?a?t???st??? TETRA
TDMA
?? p??sfe??µe?? f?sµa ?????eta? µe d?a??es?
s????t?ta? (FDMA) se ?a????a µe e???? ????? 25KHz
t? ???e ??a
FDMA
f1
f2
???e ?a???? ?????eta? µe d?a??es? ?????? se 4
?????????de?
f3
fn
???e ???st?? ??e? st? d???es? t?? s???e???µ???
?????????da p?? e??a? ??????? µetat?p?sµ??? ?at?
2 ????de? st?? ?ate???µe?? ?e???
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TETRA ??????µ??? ?e???????a
Trunking technology supports controlled use of
shared networks
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TETRA ????p?st? te???????a

• Effective priority schemes ensure delivery of
  important messages
• Direct mode communications, mobile repeater and
  gateway functions give added reliability and
  availability

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Speech Codec TDMA Frame
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Vocoder Principle
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Speech Compression
"Inbound" Frequency
TS 1
T
S

2
T
S

3
T
S
3
T
S

2
T
S
4
T
S

4
TS 1
Speech frame 1
Speech frame 2
Transmitting Radio
Micro

• 60 ms of real speech are coded and compressed for
  transmission in 14 ms
• Allows four voice channels to be time multiplexed
  on carrier frequency

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Speech Expansion
"Outbound" Frequency
T
S

2
T
S

3
T
S
3
T
S

2
T
S
4
TS 1
T
S

4
TS 1
Speech frame 1
Speech frame 2
Receiving Radio
Laudspeaker

• 14 ms of digitally coded speech is decoded and
  expanded back
• to the original 60 ms analog voice signal

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TDMA Frame Structure
Hyperframe (61.2s)
Multiframe (1.02s)
TDMA frame (56.67ms)
Time slot (14.167ms) 510 modulating bits

• Slow Associated Control CHannel (SACCH).
• Gross bit rate 17 x 510 bits / 1.02 s 8.5
  kbits/s/channel

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Essential Supplementary Services for Public
Safety Application

• Call Authorised by Dispatcher CAD
• Area Selection AS
• Access Priority AP
• Priority Call PC
• Late Entry LE
• Pre-emptive Priority Call PPC
• Discreet Listening DL
• Ambience Listening AL
• Dynamic Group Number Assignment DGNA

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Existing TETRA Public Safety Plans

• UK Home Office 100 000 users from police fire
• Germany 400 000 users from police rescue
• Netherlands Home Office 50 000 users from
  police, fire ambulance
• Belgian Home Office 40 000 users from police,
  fire ambulance
• Finland 50 000 users from police, fire rescue,
  border guard some other offices
• Austria, Switzerland, Spain, Portugal, Italy,
  Greece, Sweden, Norway, Hungary, Romania,
  Estonia, ...

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TETRA vs. Cellular Systems

• Different use requires different tools
• GSM is excellent system for cellular telephony
• Professional mobile radio needs appropriate
  technology

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Build PMR by GSM?

• Technical reasons
• Direct mode
• 300 millisecond call setup
• semi-duplex group communication
• Cost reasons
• Only high volumes make cellular phones cheaper
  compared with professional radios
• Easier to develop a TETRA system than modify GSM
• Market strategy reasons
• Too small volumes for cellular phone industry
• Too small volumes for GSM infra industry
• Too risky for GSM operators

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Spectrum Efficiency