interworking of mission critical broadband and current … · 2020. 10. 22. · • check the isi...

Interworking of Mission Critical Broadband and Current Narrowband Systems

TCCA Webinar15 October 2020

2Presentation on behalf of TCCA www.tcca.info @TCCAcritcomms

Speakers

Harald Ludwig David Chater-LeaMichel Duits Bill Janky Ari Toivonen


Agenda

1. Introduction to Interconnection and Interworking (Harald)

2. Interconnecting Systems – Experiences from a 10 Years Journey (Michel)

3. Interworking between 3GPP MC Systems and LMR Systems (Dave)

4. Interworking between TETRA and 3GPP MC Systems (Dave)

5. Interworking between P25 and 3GPP MC Systems (Bill)

6. Testing & Conformance (Ari)

7. Questions & Answers (All)

Introduction toInterconnection and Interworking

Harald LudwigTCCA Technical Forum Chairman

PART 1


Interconnection

• Communication of users across different 3GPP MC Servers

Mission Critial

LTE Network

B

Mission Critial

LTE Network

A

UE

B1UE

A1

Interconnection

Mission Critial

LTE Network

B

Mission Critial

LTE Network

A

UE

B1UE

A1

MigrationUE

A2


Interworking

ATIS

ETSI

3GPP

3GPP

MCX

System

IWF

IWF TETRA TETRA

System

IWF P25 P25

System

IWF LMR Land Mobile

Radio System

IWF

IWF

ETSI

IWF GSM-R GSM-R

System

IWF


TETRA System Interconnects

Norway

Nodnett

Sweden

Rakel

Finland

Virve

TETRA

ISI TETRA

ISI

TETRA

ISI

Harald [email protected]+43 699 1718 4567

From Idea to Interconnected Systems –The 10 Years ISI Journey

Michel DuitsSenior Principal Engineer

Norwegian Directorate for Civil Protection

PART 2NO

SE

FI


Common backgrounds

• Norway, Sweden and Finland share long borders and a history of working without boundaries with regards to public safety

• Services towards the public are without borders in the north, where the nearest hospital could be in the neighbouring country.

• Traffic across the borders is on a daily basis.

• Many use cases and actual situations where people work across borders like the forest fires in 2018 in Sweden


A start was made

NOR SWE 01

Rakel

TETRA

System

Nødnett

TETRA

System

• Limited usage as normal talkgroup• Only audio• No migration across the network

Usage of this solution showed the limitationscompared to what ISI could provide


ISI start not easy but took a flight

• ISI specified in EN300 392-3-1 up to EN392-3-7 & TS100 392-3-8 from ETSI (dec2003 & oct2007)

• At the TETRA world Congress 2011 in Budapest, DNK and MSB announced the ISI deployment in the Norwegian and Swedish national TETRA networks.

• EU funded FP7 ISITEP project deployed several pilots and real deployments of connected TETRA /TETRAPOL networks across Europe.


Technical development and End user growth side by side

• Check the ISI specification and investigating if it could work with existing national setup. • Guiding principle keep it simple, make it work, easy to deploy for operations and easy to

work with for end users. • Look and feel as at home (whenever possible).

1. Work and communication procedures to align and extend2. Formal agreements between operators and user organisations3. A shared fleetmap4. Training5. Exercises6. Operational support and follow up forum


ISI provides new user experiences

• National boundaries does not limit TETRA services

• A migrated MS can use additional features in the visited network

• Best serving RSSI between 3 countries and 3 networks


ISI NOSE, FINO, FISE, FINOSE, 2020 -future

• Benefits and deployment the last 2 years• Concept tested for migration and how to contact agencies (hailing principles)

• FINOSE structure to involve end users from 3 countries and different agencies to communicate.

• IWF functionality in focus for bridging from TETRA narrowband to Mission Critical broadband

• Use benefits from TETRA ISI as baseline for Interconnection


The next 10 years…

TETRA

ISI

Mission Critical Interconnection

Rakel Agnet 4G

Finland

Virve

Sweden

Rakel

Norway

Nødnett

IWF TETRA

3GPP

MCX

System

3GPP

MCX

System

VIRVE

2.0

System

Nødnett

Connect 4G

IWF TETRA

IWF

TETRA

VIRVE APPI 4G


Thank you

@ ISI Workgroup meeting #100 11.12.2019

Michel [email protected]+47 23 00 57 00

Interworking between3GPP MC systems and LMR systems

Dave Chater-LeaFellow of the Technical Staff, Motorola Solutions UK Ltd.

and Vice Chair of ETSI TC TCCE

PART 33GPP

MCX

System

IWF GSM-R

IWF P25

IWF LMR

IWF TETRA

Presentation on behalf of TCCA www.tcca.info @TCCAcritcomms 20

3GPP MC Systems

• 3GPP developed Mission Critical applications for operation on LTE (4G) and later technologies (5G on)

• First release of MCPTT providing speech services in 3GPP Rel-13 (2016), enhanced with MCVideo and MCData (Rel-14, 2017, onwards)

• Interworking with Land Mobile Radio (primarily for TETRA and P25) added in Rel-16 (June 2020)

• Further enhancements in progress for Rel-17, mainly for the needs of the rail industry

• Interworking specifications are provided for speech services (MCPTT) and Short Data Service (MCData)


Interworking facilities

• Group affiliation (attachment)• Group controlled by either system

• Group call• Groups controlled by either system

• Group regrouping (where supported by LMR system)• Note: additional group regrouping procedures have been added

to 3GPP standards

• Individual/private call• Originated or terminated in either system

• Emergency call• Group or individual calls both supported

• Transmission control• Prioritisation, interrupt and queuing (where supported)

• Short data messages• Originated or terminated in either system• Individual or group destinations

• Encrypted communications• End to end encrypted speech and data• Transport of key management messages

Land Mobile Radio (LMR) systems:

• TETRA

• P25

• Some support for analogue FM

• Other technologies out of scope• However generic approach of 3GPP Interworking

Function (IWF) interface could be adopted for other technologies in the future, provided IWF behaviour remains the same

• Work in progress to introduce GSM-R for rail industry

Out of scope:

• MCVideo• LMR systems do not have bandwidth for high

quality video, and do not have video transport standards

• MCData file distribution etc• Limits on appropriate sizes of file that can be

transported over LMR system

• Most data exchanges are between mobile and fixed data host, not mobile to mobile


Interworking behaviours

• A mobile device on either type of system should not need to act differently when communicating with a device on the other type of system

• Behaviours of MC system servers should be impacted as little as possible

3G

PP

net

wo

rk

MC system

LMR system

MC system

3G

PP

net

wo

rk

LMR system

IWF


3GPP interworking reference model

• 3GPP do not specify the operation of the IWF – but its behaviour is implied by the interface specifications

• From 3GPP perspective, IWF ‘looks’ like another MC system in a different security domain

• Interactions similar to those with an interconnected MC system

• IWF simulates functions of MC service servers and common service core servers

• The Mission Critical User Equipment (MC UE) does not need to have any extra functionality for interworking calls

• Except where fully end-to-end security using LMR mechanisms is used, in which case UE needs to support LMR vocoder and encryption mechanism

• Security gateway terminates 3GPP security processes• Key management and encryption

Common services core

Identity management

server

Group management

server

Configuration management

server

MCPTT server

Key management

server

Location management

server

IWF

Defined in 3GPP TS

23.283

IWF-1

MCData serverIWF-2

IWF-3

Secu

rity

gat

eway

Spec

ifie

d in

3G

PP T

S 33

.18

0


IWF functionality

• Identity translation – an LMR identity is presented as an MC service ID (a URI) within the MCPTT/MCDatasystem, and MC service IDs are presented as LMR identities within the LMR system

• Security – the IWF terminates 3GPP security, and provides 3GPP key management services for MC UEs that need to communicate with LMR users

• IWF also provides support for LMR key management messages

• Transcoding – conversion of speech between MCPTT (AMR-WB) and that used by the LMR standard

• Codec negotiation, if the LMR codec is supported by the MC UEs

• Translation of short data service message format

• Transfer of location information, if supported

• Work in progress to support railway applications – functional alias, GSM-R


Group communications

• Group communications on an MC system normally require group members to be listed in group configuration, and for group members to affiliate to the group before they can take part in group calls.

• For MC system groups used for interworking, either:• Each LMR group member is configured as a group member, and each sends an individual affiliation to the MC service server via

the IWF to participate in group communications (i.e. the same as communications within an MC system);

• or:• The IWF can affiliate on behalf of LMR system group members when one or more group member wants to participate in

communications in the group, and can de-affiliate when no one on the LMR system wants to remain in the group

• Individual group members on the LMR system do not need to be individually provisioned on the MC system.

• IWF identity is configured as a group member

• LMR users’ identities are still carried in call setup, talking party identification etc

• For LMR groups, the IWF will receive individual affiliations for each group member on the MC system• LMR system will manage the group, and will send individual media (speech) streams to each MC system group participant


3GPP interworking specifications

• Stage 2: 3GPP TS 23.283

• Stage 3: 3GPP TS 29.379 (MCPTT call control)3GPP TS 29.380 (media control)3GPP TS 29.582 (MCData)

• Security: 3GPP TS 33.180 (MC system security)

Interworking betweenTETRA and 3GPP MC systems

Dave Chater-LeaFellow of the Technical Staff, Motorola Solutions UK Ltd.

and Vice Chair of ETSI TC TCCE

PART 43GPP

MCX

System

IWF GSM-R

IWF P25

IWF LMR

IWF TETRA


Interworking reference model

• TETRA interworking interface = 3GPP specified interface• Specification will define interaction between information exchanged on 3GPP defined reference

points, and TETRA MS• Internal operation of the TETRA SwMI is out of scope of TETRA standards

3GPP defined reference points

Out of 3GPP scopeSpecified in ETSI TCCE

SwMIMC system IWF

IWF-1

MSUmIWF-2

IWF-3

TETRA system

TS 100 392-19-1

Interworking interface for TETRA systems


Interworking functionality

• TETRA MS will consider the MC system to be another TETRA system connected by ISI• MC users will be addressed as TETRA MSs with a different Mobile

Network Identity, requiring the use of extended addressing• Functionality specified will follow the functionality adopted by the ISI• No air interface changes foreseen

• IWF will manage how identities are represented in each system• Use of configuration tables or algorithms is left to deployment

• Speech transcoding by the IWF, or end to end use of TETRA ACELP (with or without encryption)• Speech frame format defined to carry TETRA speech in MC system

included end-to-end encryption synchronization frames• TETRA key management messages will be transported by MC system

3GPP defined reference points

Out of 3GPP scopeSpecified in ETSI TCCE

SwMIMC system IWF

IWF-1

MSUmIWF-2

IWF-3

TETRA system

TS 100 392-19-1Interworking interface for TETRA systems


Deploymentscenarios

• Different countries have different models for TETRA and proposed MC system deployment• Nationwide TETRA system and geographic or

organizational MC systems

• Multiple TETRA systems, and one or many MC systems

• The specification describes one instance of the interface – nothing prevents multiple networks, multiple interfaces

MC

MC

MC

TETRA

TETRA

TETRA

TETRA

MC

TETRA

TETRA

TETRA

MC

MC

TETRAMC

M:1 1:N

M:N

Note: MC to MC and TETRA to TETRA ISI also possible in model, but out of our scope!

Deployment scenarios


TETRA interworking security

• Authentication is carried out independently in each system

• 3GPP security applied as far as a security gateway function in the IWF

• TETRA air interface encryption applies to air interface in TETRA system

• TETRA end to end encryption can be terminated at the IWF, or can operate fully end to end to the MC UE• In this case, the TETRA ACELP vocoder is used for the audio

SwMI

MC system

IWFMSUm

TETRA system

Secu

rity

ga

tew

ay

3GPP MC security

MC UE

TETRA air interface encryption

3GPP e.g. LTE network

TETRA end to end encryption optionsTETRA end to end encryption options


ETSI and TCCA Interworking specifications

• ETSI Technical Reports on interworking:• TR 103 565-1 ‘Study into interworking between TETRA and 3GPP mission critical services’, published October 2017• TR 103 565-2 ‘Security of interworking between TETRA and Broadband applications’, by TCCE WG6 published May

2018

• TS 100 392-19-1 Protocol specification is work in progress• Work in progress in TCCE WG4

• Based on 3GPP Rel-16 specifications

• TS 100 392-19-2 Format for the transport of TETRA speech over mission critical broadband systems, published March 2019• Format for speech transport formally registered with IANA https://www.iana.org/assignments/media-

types/audio/TETRA_ACELP_BB

• TCCA Security and Fraud Prevention Group (SFPG) Recommendation 14 ‘Security of Interworking between TETRA and 3GPP MC systems’, published December 2019• Available under NDA from [email protected]

https://www.iana.org/assignments/media-types/audio/TETRA_ACELP_BB

Interworking between P25and 3GPP MC systems

Bill JankySr. Standards Engineer

FirstNet

PART 53GPP

MCX

System

IWF GSM-R

IWF P25

IWF LMR

IWF TETRA

FirstNet Update

North American Progress for MCPTT – LMR/LTE System Interworking

Bill Janky

October, 2020

Sr. Standards Engineer

35

North American progress for MCPTT - LMR System Interworking

▪ Standards Organizations

▪ ATIS/TIA joint committee, JLMRLTE, is developing the Stage 2 architecture

▪ TIA TR-8 is defining the Stage 3 protocols

▪ JLMRLTE

▪ Work has been unofficially organized in phases with architecture hand-off to TIA at phase completion

▪ Phases 1 and 2 are complete; phase 3 is in progress

▪ Phases 1 and 2 support a robust set of P25 trunking features

▪ Phase 3 will support all of the common P25 trunking features, and a subset of P25 conventional features

▪ TIA

▪ Completed Stage 3 and will publish specifications supporting phases 1 and 2 in Q4, 2020

▪ ATIS/TIA development will continue through 2021

▪ Complete conventional radio LMR interworking including analog FM conventional

36

Architecture overview

▪ Reference points IWF-1, IWF-2, and IWF-3 (between the IWF and the 3GPP MC system)

▪ IWF-1, IWF-2 and IWF-3 are the interfaces defined in 3GPP TS 23.283.

▪ L102-T (between the IWF and a TIA-102 trunking LMR system)

▪ Provides interconnection between a P25 trunking LMR system and the IWF.

▪ L102-C (between the IWF and a TIA-102 digital conventional LMR system)

▪ Provides interconnection between a P25 conventional LMR system and the IWF.

▪ L603 (between the IWF and a TIA-603 conventional LMR system)

▪ Provides interconnection between an analog FM conventional LMR system and the IWF.

IWF

TIA-603ConventionalLMR System

IWF-1TIA-102

LMR system

IWF-2

IWF-3

3GPP MCPTTSystem

3GPP MCDataSystem

3GPP Group

Management

L102-T

L102-C

L603

37

So what does this look like for FirstNet?

▪ MCPTT via LTE is what 3GPP SA6 has been defining

▪ Interface to P25 is ISSI/CSSI

▪ Interface to conventional FM could be ISSI, FSI, or anything, but it has not been defined yet

So, the IWF looks like an MCX server on the LTE side, and it will look like an ISSI node (Home/Serving RFSS) on the LMR side

Note: ISSI = Inter-RF Subsystem Interface. It connects P25 systems together and facilitates roaming from one P25 system to another. The CSSI is basically the ISSI except it connects console subsystems into P25 systems.

MCPTT

Service

UEMCPTT

User

Conventional

FM User

P25

User

P25

LMR

System

Conventional

FM LMR

System

P25 SU

U102

Conventional

FM SU

UFM/102

Conventional

FM Dispatcher

P25

Dispatcher

P25

Console

Conventional

FM Console

L102C L102T

MCPTT Console

PTT

Dispatcher

IWF

GLTE

Joint ATIS/TIA

3GPPTIA

38

What will this ultimately facilitate?

▪ All major features that first responders expect are being built into the interworking standards

▪ Group calls, Emergency group calls

▪ Emergency Alert

▪ Private calls

▪ Encryption

▪ User and Group IDs

39

The Current Climate

▪ Problem 1

▪ Sheer numbers of disparate radio systems

▪ Statewide, Large Metropolitan, Local Systems

▪ A nationwide response – Wildland Fires, Hurricanes, Tornados, and Flooding

▪ Small agency Mutual Aid response

▪ Problem 2

▪ Overhead costs

▪ The system

▪ The devices

▪ Problem 3 – They needed PTT NOW!

▪ Broad adoption of disparate commercial PTT systems

▪ Filling the void in lieu of standards

▪ ROIP and ISSI

40

Radio over Internet Protocol (RoIP) Inter-RF Subsystem Interface (ISSI)

Interface Options: Pros & ConsP

ros

• Cost effective• Wireless / not backhaul dependent• Can be rapidly set up anywhere within

coverage

Co

ns

• Provides basic voice only to tie one group on LMR to one group on LTE

• Limited functionality – voice only• A donor radio is required for each talkgroup

Pro

s

• Provides system interface• Offers high functionality

• User ID, Emergency• Scalable to large systems

Co

ns

• More Expensive• Requires backhaul connectivity• Currently only supported on P25 systems• Configuration is not a task for the timid

41

Q&A

42

Thank You

Testing & Conformance

Ari ToivonenErillisverkot

PART 6


Testing

• Conformance testing• Typically done using a test tool, but do such tools exist?

• How far would you trust those results without testing in real life?

• Interoperability testing• Multiple P25/TETRA - MC combinations to be tested

• In practice, many operators only care about one combination

• Testing in live networks often challenging• A test environment preferred


Conformance

• Conformance to standards • A typical contractual requirement

• Basis for interoperability

• Lowers the risk for or amount of case specific modifications

• Conformance test cases for interworking• IWF-1/2/3: based on 3GPP specifications

• How much of the other MC, P25 or TETRA functionality needs to be included?


Formal conformance testing

• Why do we need this?• Benefit for PPDR operators: less local testing required

• Benefit for suppliers: test once, sell globally

• How often should this be done?• At every version upgrade?

• What about security patches?

• A need for a trusted independent test authority• No obvious single party to do this for MC, P25 and TETRA

Ari [email protected]+358 40 626 8231

Questions & Answers

TCCA Webinar15 October 2020

PART 7

THE NEW VIRTUALEXPERIENCE

2-6 November 2020

SPONSORED BY: PRESENTED BY:

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