1. TETRA ARCHITECTURE AND INTERFACES
Dr. M. Nouri
Marconi Mobile

2. Agenda 1. TETRA 1 Architecture and Standard Interfaces
2. Description of Individual Interface
Network Aspects and Scenarios
Services
Protocols
3. TETRA Standard Gateways
Features
4. TETRA Release 2 Architecture and Interfaces
5. Conclusions

3. Typical TETRA Network 1b 3 1a 5 2 6 4 Central Network Management TETRABS BS
TETRA
Infrastructure
NMS 5
Another
TETRA
Network 2 . BS BS BS BS
1. Air interface (AI)
- Trunked Mode
- Direct Mode
2. Inter-system interfaces (ISI)
3. Peripheral equipment interface(PEI)
4. Line station interface (LSI)
5. Network management interface (CNMI)
6. Gateways to PSTN, ISDN and PDN
Note: All interfaces/gateways are standards except CNMI which is a recommendation. 6
Remote Line Station (Despatcher) 4
PSTN, ISDN
PDN

4. Air Interface (AI) Variants
DMO
AIR I/F
TMO
AIR I/F
PEI
TETRA Voice plus Data (V+D)
- Trunked Mode Operation (TMO)
- Direct Mode Operation (DMO)
Free DMO
Managed DMO
Packet Data Optimised (PDO)
- Originally Narrow-band
- Later Digital Advanced Wireless
Services (DAWS)
- Now PSPP, a joint ETSI-TIA initiative
(Project MESA)

5. TM V+D Air Interface V V D D V D V V D Physical Layer Features
TETRA
Infrastructure
TDMA
FRAME V
Uplink V
TS 1 D D
TS 2 V D
TS 3 V
Amsterdam November 1999
Downlink V
TS 4 D
Physical Layer Features
TDMA Structure
4 User Channels
25 kHz Channel Spacing
36 kbit/s Transmission Rate
/4 DQPSK Modulation
7.2 kbit/s Speech Coding (including error
correction)
TS = Time Slot

6. Half Duplex/Full Duplex
TM V+D AI Services
Speech
Data
Circuit mode
Packet mode
Short data service
Supplementary Services
Call Control
Mobility Management
Security Services •
Speech/Data/SDS –
Individual Call
Group Call (including Broadcast Call) – •
Speech –
Half Duplex/Full Duplex –
Clear/Encrypted •
Packet Mode Data
- Connection Oriented/Connectionless (X.25)
- IP Packet Data (V.4 and V.6) •
Short Data Service
- 16, 32, 64 and 2048 bits packets

7. TM V+D AI Data Rate Capacities (kbit/s)
Number of
Timeslots 1 2 3 4 No
Protection
7.2
14.4
21.6
28.8
Low
4.8
9.6
19.2
High
2.4
BANDWIDTH ON DEMAND
Real-time circuit mode data applications e.g.
- Video
- Slow Scan TV
Increased throughput (or speed) in Packet
Mode applications such as:
- File Transfer
- Data Base Updates
- Internet Access
Bandwidth on Demand: Applications

8. TM V+D AI Protocol Stack
CONTROL PLANE
USER PLANE
Speech
Circuit Mode
Data
Mobility
Management
Packet
Data
Call Control
Short Data
Supplementary
Services MM
CMCE PD
Layer 3
Mobile/Base Link Control Entity
Voice and Circuit Mode Services use the physical layer and the lower MAC
Other services enter via Service Access Points (SAPs) at the top of layer 3
Open Standard APIs (e.g. WAP and others) are defined for seamless access at these access points
Application layers will be accessing the open standard (or proprietary) APIs
On the base station side, the physical layer connection to switching nodes are normally via 64 kbit/s bearers sub-multiplexed with 8 kbit/s channels
Logical Link Control
Layer 2
Medium Access Control
Physical Layer
Layer 1

9. Direct Mode AI Scenarios
2. GROUP CALL
1. INDIVIDUAL CALL
NETWORK
NETWORK
AUTHORIZING
MOBILE STATION C 1
ABC 2 4
MNO DE
GHI V 9 6
PQR
XYZ
Basic
- Individual Call (Half Duplex)
- Group Call/Broadcast Call
Dual Watch
- Monitoring TM control channel when in DM
- Monitoring DM channels when in TM
Managed Direct Mode
- DM communication requires authorization
- Authorization signals emitted periodically
from an Authorizing Mobile Station
3. DUAL WATCH
4. MANAGED DIRECT MODE

10. Direct Mode AI Scenarios (contd.)
REPEATER
GATEWAY
NETWORK
6. DIRECT MODE GATEWAY
5. DIRECT MODE REPEATER
REP/GW/
AUTHORIZING
MOBILE
REP/GW
NETWORK
NETWORK •
Repeater –
Type 1A (same frequency for uplink &
downlink, single call)
Type 1B (different frequencies for
uplink & downlink, single call)
Type 2 (supports two simultaneous
calls)
Gateway
- Interconnects DM and TM users
Managed Repeater, Gateway or both
Combined
7. DIRECT MODE REPEATER/ GATEWAY
8. MANAGED REPEATER/ GATEWAY

11. Direct Mode Call Control
DM AI Protocol Stack
CONTROL PLANE
USER PLANE
Circuit Mode Data
Call Control
Intrinsic Services
Speech
Short Data
Direct Mode Call Control
Layer 3
V+D DMO : Services
Data Link Layer
Layer 2 •
Basic services
Physical Layer –
speech (half duplex)
Layer 1 –
circuit mode data (7.2 kbit/s), high &
low protection –
short data service •
Intrinsic services (3 in total), included
at call set-up •
Addressing (including repeater,
gateway) •
Security services

12. Services Supported by ISI
To Other
Regional SCN
To other
TETRA Networks
ISI
Regional
To other
Local
SCN
ISI Applications
Measured System Expansion
Multi-sourcing of the Infrastructure
Interoperability between different TETRA
Systems
Cross-border Roaming
Individual call
Group Call
Mobility Management
Short Data Service
Supplementary Service
Security
SCN: Switching Control Node
NMS: Network Management System
BS: Base Station
To other
Services Supported by ISI

13. Example: ISI Group Call Configuration
CONTROLLING AND
PARTICIPATING
NETWORK
REQUESTING AND
PARTICIPATING
NETWORK
ISI
ISI : Mobility Management
Migration (Individual and Group)
De- Registration (individual)
Group Attachment/Detachment
Linking and Unlinking of Groups
Database Fault Recovery
TETRA Authentication
OTAR for Key Management
PARTICIPATING NETWORK

14. ISI ISI : Protocol Stack Physical Layer based on Digital 64 kbit/s
TETRA INFRASTRUCTURE 1
TETRA
INFRASTRUCTURE 2
ton
TETRA ANF
TETRA ANF
Specific TETRA Operation
c TETRA operation
Specific TETRA Operation
ITU-T Rec. X.229
ISI
ITU-T Rec. X.229
ISO/IEC 11582
ISO/IEC 11582
ISO/IEC 11572
ISO/IEC 11572
ETS and 2
ETS and 2
Physical Layer based on Digital 64 kbit/s
Connection
TETRA Voice Coding maintained
User Information encoded as 8 kbit/s
N x 8kbit/s Multiplexing according to ITU
Rec. I. 460
Higher layers according to PSS1 (Q.Sig.)
standard
Layer 1
Layer 1
PRIVATE SIGNALLING SYSTEM 1 (PSS1) USED IN ISI STANDARD

15. IP Inter-working Interface
Host
Packet Data Network
IPI
Inter-Network Backbone Gi Gp Gi
GGSN BG BG
GGSN Gn Gn
Internal Backbone
Internal Backbone
ISI
IP Inter-working (IPI) plus roaming support between two TETRA networks is based on GPRS Tunneling Protocol
Standard GPRS interfaces Gp, Gn and Gi are used for inter-working directly or via a third IP network
Roaming profile is supplied through ISI between home and visiting databases
BG is the Border Gateway providing Gp with security functions
TETRA SNDCP* sub-layer and the Gateway GPRS Support Node (GGSN) provide IMSI-ITSI association
* SNDCP: Sub Network Dependent Convergence Protocol
HDB
VDB
HDB
VDB
TETRA
Infrastructure 1
TETRA
Infrastructure 2

16. Peripheral Equipment Interface (PEI)
MT2
TE2
TETRA
INFRASTRUCTURE
Services offered by PEI
Set-up & Communication
- Packet Data
- Circuit Data
- Short Data
Set-up & Control
- Speech Calls
Access to:
- Data on MT2 & Infrastructure
- User Applications on MT2
PEI

17. Access Services through PEI Protocol Layers
APPLICATIONS
TCP
UDP IP
TNP1
Three access services are defined across the PEI
AT (attention) Commands are used to access Circuit
Mode Data Service, Short Data Service and Radio
Configuration
TNP1, TETRA Network Protocol 1, allows remote access
to Circuit Mode Control Entity (CMCE), Radio
Packet Data Service is accessed via PPP platform in the
PEI by TCP or UDP protocols through the intermediate IP
layer
Physical Layer: ITU-T V.24/V.28 with speeds
normally < 20 kbit/s (up to 64 kbit/s possible)
PEI
DOMAIN
Access Services through PEI Protocol Layers
PPP
V. 24/V. 28
TO MOBILE STATION

18. Standard API and Applications
Internet
Access
AVL
Telemetry
Standard API
WAP
Proprietary
Bearer Service
IP Packet
Data
Circuit
Mode Data
SDS
TETRA ADAPTATION
LAYER
Data Application Examples
Data base interrogation/updates (p,s)
File transfer (c,p)
Messaging/paging (p,s)
Vehicle location (p,s)
Telemetry (p,s)
Video transmission (c)
Image transfer/graphics (c,p)
Computer aided despatch (p,s)
Mobile office (c,p,s)
Network

19. TETRA IP Network and Internet
TETRA as an IP Network
Content
Provider
Network Management
Center
WAP
Terminal IP
WAP GW
Internet
Database
LAN
Server IP IP
Corporate
Intranet
IP Switching/
RoutingNetwork IP IP
GPS
Bluetooth IP
TETRA IP Network and Internet
Control
Room
Server IP
Internet/intranet connectivity
- WAP enabled handset and micro-browser, or:
- Using data terminal connected to handset
via PEI (wired or bluetooth connection)
- WAP gateway for WML conversion and HTML
Standard APIs for a range of applications
- AVL
- Others
Network IP routing to BS level already available
User to user voice over IP is now a real possibility
IP routing throughout the network in the near
future
TETRA Infrastructure IP
Voice/IP
Dispatcher

20. Line Station Interface (LSI)
TETRA INFRASTRUCTURE BS BS
ISDN
LSI BS BS BS
LSI : Services BS BS
Connectivity Options •
Voice
LSI
Basic Rate ISDN
Primary Rate ISDN
64 kbit Leased Line •
Circuit mode data •
Packet mode data •
Short data service •
Supplementary services, except; –
Access Priority –
Ambience Listening
Control Functions • –
Mobility –
Registration –
Authentication –
ITSI, GTSI attach, detach
TETRA World Congress
Amsterdam November 1999
Slide 26

21. Central Network Management Interface
TETRA 1
ISI
TETRA 2
LNM
LNM
ISI
ISI
TETRA 3
LNM
Performance Management
Fault or Maintenance Management
Subscriber Management
Accounting Management
Security Management
Central Management of more than 1
TETRA system
Primarily a monitoring role
Only a sub-set of LNM functions
Interoperability between different
manufacturer’s LNM
Management of ISI and inter-TETRA
links
Management of wide area roamers
CNM

22. PSTN Gateway PSTN PSTNGW Clear Mode Speech (Point-to-Point or
Point-to-Multipoint)
Maintenance of Signalling across the Gateway
Echo Cancellation (Full-Duplex)
Request to transmit from PSTN or Voice
Detection Device (Half-Duplex)
TETRA Codec Function
Numbering Conversion
No Interaction with Supplementary Services

23. ISDN Gateway ISDN 2B+D 30B+2D ISDNGW
Matching TETRA signalling and ISDN DSS1
signalling
Addressing a TETRA user from ISDN using two
stage dialling or via ISDN supplementary services
Primary and basic rate (not multiple gateways on
the same basic rate bus)
Circuit mode data not part of this standard
Request to transmit from ISDN or voice detection
device (half duplex)
Partial invocation of TETRA and ISDN supplementary
services across the gateway
Trans-coding and rate adaptation to 64 kbit/s PCM

24. PDN Gateway PDN PDNGW X.25 X.75 Packet Data Services
LAN
Server
Database
X.25
X.75
PDNGW
PDN
Packet Data Services
- Connection oriented
- Connectionless
TETRA Network seen as:
- Data network node
- Data terminal
X.25 Protocol (X.75 for inter-working as a node)
Address Mapping to X.25 Addresses

25. What next for TETRA?
TETRA RELEASE 2
TAPS
TEDS
Proposed TETRA Enhancements during TETRA Release 2
TETRA Enhanced Data Service
Full Compatibility with TETRA 1
Allows migration from TETRA 1
Standardisation in progress
5 technologies proposed
Designed for all TETRA market
sectors
TETRA Advanced Packet Service
An Overlay network
Based on the EDGE technology
Standardisation drafting completed
Designed for PAMR market
High speed packet data (~ 400 kbit/s)
Additional (& better quality) voice codecs to
inter-work with 3G
Enhancement of air interface in terms of spectrum
efficiency, network capacity and system performance
Inter-working and roaming with GSM, GPRS and
UMTS
Evolution of TETRA SIM and convergence with USIM
Long range TETRA (airborne, maritime, rural
TETRA…)

26. TAPS Architecture & Interfaces
External Packet Data Networks Gi Gi Gi
TETRA
V+D
IPI
(Gp)
GSM/
E-GPRS
TAPS OVERLAY Gp
TETRA
V+D
ISI
(Gr)
Only interfaces at periphery of TAPS infrastructure have been defined in TAPS standard
Gi is a standard GPRS interface for connection to external IP networks (includes roaming support)
IPI is the IP interface between two TETRA infrastructures
Gr interface is used to retrieve service roaming profile. Between two TETRA networks this is done via ISI
IPI is identical to the standard GPRS interface Gp but with TETRA identities
Gp includes security requirements Gr
Gi, Gp & Gr: standard interfaces
used in E-GPRS networks

27. UMTS Core Network Transit Layer TETRA Infrastructure
TETRA in 3G Era
Network
Management
Service
Nodes
Customer
Care Billing
UMTS Core Network
Transit Layer
Network
Management
TETRA1
Access
Gateway
TETRA completely separate from the 3G network
TETRA and 3G networks inter-work via a gateway
(to be standardized)
Services in 3G network are offered to TETRA
users subject to TETRA access type, i.e.TETRA 1,
integrated TETRA 1 + TEDS, and TAPS
Separate connections between TETRA infrastructure
and external networks
Billing/roaming agreement needed between the two
operators
TETRA
Infrastructure
UMTS
Access
GSM
Access
TAPS
Access
TETRA1
+TEDS
Access

28. Conclusions TETRA 1 Architectures and Interfaces allow:
Spectrally-efficient feature rich communication
Choice of trunked or direct modes
Interoperability between different TETRA networks
Multimedia services, Internet access and mobile
office capability
Extensive data applications capability
Inter-working with public networks
High level of security
TETRA Release 2 provides the future upgradability and high
speeds required in the 3G era.