public safety prioritization on commercial networks• it is forbidden in many countries as it could...

• Introduction – Key drivers

• Market trend for Public Safety over commercial mobile networks - (Figures from IHS Markit)

• Public Safety constraints to be considered by commercial Mobile Network Operators

• Available prioritisation mechanisms in 4G on a shared network

• Regulation and Legal aspects

• Public Safety service provider implementation aspects

• MNOs implementation aspects

• Feedback from early adopter ESN UK

• Innovative prioritisation mechanisms and evolution towards 5G

Marc BALLIET, Public Safety business consultant, Nokia

Public safety prioritizationon commercial networks

Key drivers to implement PS over MNOs

• MNOs have already widely rolled out LTE allowing a fast time to market of

PS broadband services on top of their network.

• MNOs have usually a large amount of spectrum whereas in many countries

there is very little or no spectrum available for a PS dedicated network.

• Sharing the network with MNOs can reduce the total cost of ownership for

the PS agencies.

• Hosting PS services can benefit the image and brand of the MNO.

$

Market Trend

• Ubiquitous coverage

• Resilience ⎻ Redundancy⎻ Site hardening⎻ Isolated operations

• Interoperability

• OoS Prioritization• Access Class Barring

• Admission control & pre-emption

• Security risk assessment

• E2E Security architecture

implementation

• Managed security

Availability

Performance Security

Public Safety constraints to be considered by Mobile Network Operators (MNO)

Ubiquitous coverage:• Indoor• Outdoor• Tunnels• Rural

Human errorComms issues

Site failureNode failure

Availability: Coverage, Resilience, Interop

Resilience:• Redundancy• Power backup• Isolated Operation

PTT interoperability betweenPMR and LTE

Access control• Determines which users are allowed to access

the cell and when they can try to access• Access Classes (0-9, 11-15 on USIM)1Admission control (and pre-emption)• Determines which users are served and the type

of service offered• ARP (Allocation and Retention Priority)2Traffic Prioritization (Scheduling)• Determines the quality of service (throughput and

latency) for the offered services in use• QCI (QoS Class Identifier)3

Performance: Prioritization mechanisms on commercial networks

Commercial subscribers

Police

High priority access

Low priority access

S-MVNO LTEnetwork

High priority based on Access Class 11–15 on U-SIMfor public safety


PoliceHigh priority access treated like emergency call

Low priority access rejected by eNodeB

LTEnetwork

Overload situation

eNodeBtemporarily rejects low priority subscriber access to ensure service continuity

Performance: Access Class Baring (ACB)How it works


PoliceHigh priority access for police

Low priority access for commercial

S-MVNO LTEnetwork

Insufficient resources New Commercial subscribers

Additional commercial subscriber request

Allocation & Retention Priority (ARP) determines bearer allocation




S-MVNO LTEnetwork

Insufficient resources New Commercial subscribers

ARP temporarily rejects creation of new bearer for additional subscriber –admission control

Bearer allocation rejected

Performance: Allocation and Retention Priority (ARP)Admission control: how it works




S-MVNO LTEnetwork

Fire ServicesHigh priority fire subscriber request

Allocation & Retention Priority (ARP) determines bearer allocation



Low priority access removed

S-MVNO LTEnetwork

Insufficient resources

Fire ServicesARP creates new high priority access

ARP creates new high priority EPS bearer for Fire and removes low priority bearer – pre emption

Access Removed

Performance: Allocation and Retention Priority (ARP)Pre-emption: how it works

Guaranteed bit rate (GBR)

QCI 65 Mission critical User Plane PTT voicePriority: 0.7; Delay : 75ms; Packet loss : 10-2

QCI 66 Non-Mission critical User Plane PTT voicePriority: 2; Delay : 100ms; Packet loss : 10-2

QCI 67 Mission critical Video User PlanePriority: 1.5; Delay : 100ms; Packet loss : 10-3

Non-Guaranteed bit rate (Non-GBR)

QCI 69 Mission critical signalingPriority : 0.5; Delay : 60ms, Packet loss : 10-6

QCI 70 Mission critical dataPriority : 5.5; Delay : 200ms Packet loss : 10-6

Mission critical communications prioritized versus commercial traffic

15x improved throughput for PS customers recorded on live trial in Finland with active MC-PTT QCI implementation

High Med Low

New QoS Class Identifiers (QCI) developed for Public Safety in 3GPP

Regulation and Legal Aspects• Access Class Baring (ACB) implementation:

• It is already used in many countries as « defence » mechanism against overload• It is forbidden in some countries like Austria

• National Roaming implementation for Radio Access Network (RAN) redundancy• It is forbidden in many countries as it could harm competition between the MNOs• It is already allowed in Norway for qualified users with a role of vital interest for society

• Net Neutrality: means that MNOs must handle traffic in equal manner• US Federal Communications Commission (FCC) adopted network neutrality principles in

2005 but repealed this decision in 2018. Discussions on-going to reconsider it• EU is in favor of net neutrality, and this is backed up by regulation. • PS operators need to consider net neutrality depending on the specificities of the

regulation and laws in each country. They should plan these legal aspects at a very early stage of their PS broadband implementation schedule

• Legislative status in some countries:• Belgium: A royal decree has been issued stating that MNOs must prioritize PS traffic. • Finland has adopted the “Virve 2.0” law that ensures the legal base for BB PPDR• Norway: First responders have already the ability to pre-empt 3G and 2G voice traffic

Public Safety service providersimplementation aspects

Feedback from French MoI: • Using MNO services means using a shared network without a full control of the radio resources.• The fear of congestion comes with the massive rollout of broadband video, such as police body worn cameras.• Today there is no clear prioritization mechanism in place to perform content based prioritisation.

-> French MoI is leading a TCCA Task Force to tackle this issue• Dealing with MNOs means negotiating an SLA about service availability rate.• Using priority and pre-emption, national multi-MNO roaming can lead to 99,99xxx % availability rate for 98% of population.

• But it’s not enough: for PPDR issues we also need resilience. • In extreme cases (hurricane, wildfire destroying infrastructure, terror attack)

• First responders need to remain fully independent to be able to quickly deploy their own network• those events happen rarely and concern generally a small area (a few square km).• That’s why we need tactical networks of relevant sizes to complete the solution. BYOC concept

Feedback from early adopter ESN UK

• Allocation and Retention Priority (ARP) has been implemented at ESN• GBR bearers should be used for relatively low-throughput services (e.g., voice calls) rather than high bit–rate

services (e.g., Video)• A single GBR service demanding a high guaranteed bit rate can cause disproportionately high resource impacts

and multiple pre-emptions • Pre-emption is applied where a request cannot be satisfied with the available resources:

• Higher ARP priority bearers preempting lower ARP priority bearers in accordance with 3GPP. • If two pre-emptiable users have the same ARP priority in a VoLTE call when a higher priority PTT call comes the

VoLTE user at the cell edge will be pre-empted in preference as more resource-intensive.• It may be necessary to pre-empt multiple UEs to admit one UE’s new request

• Congestion Control is not normally necessary as there should be a mix of non-GBR and GBR traffic• As non-GBR traffic is scheduled less when necessary. • For congestion due to mobility and varying bit rates, the eNB would release low-priority ARP GBR services first. • If multiple bearers with equal priorities are potential targets, then the bearer using the most resources would be

targeted first.

Innovative prioritization mechanisms and evolution towards 5G: LSA

Licensed Shared Access (LSA):• Use of spectrum, whenever and wherever it is unused by incumbent users.• LSA principle is frequency and technology agnostic.

Incumbent Spectrum Owner(s): MNOs

LSA Licensee(s):PS Agencies

National Regulator Authority (NRA)

Dialogue to definesharing

framework

NRA issues individual Right to Use to LSA

Licensee

LSA trials have been done at:• Spain (Oct 2015),• Finland (March 2016),• France (October 2016)• Italy (November 2016)• Netherland (January 2017)Reports of all these trials can be found here: https://www.cept.org/ecc/topics/lsa-implementation

• LSA necessitates that it is approved by the owner of the spectrum.• The advantage and drawbacks of such a procedure are still to be assessed.

Innovative prioritization mechanisms and evolution towards 5G: Network Slicing

Network slicing enables a customisable level of connectivity and priority for a plethora of critical applications, each with widely differing service characteristics, yet carried over the same physical network.

Innovative prioritization mechanisms and evolution towards 5G: Non-terrestrial Networks

3GPP has completed a “5G for non-terrestrial networks“ technical report (TR 38.811)

• Extending the reach to areas that cannot be optimally covered by terrestrial 5G network.

• 5G service reliability and resiliency for public safety systems

• Connectivity on board airborne vehicles (e.g. air flight passengers, UASs/drones, etc.), other moving platforms (vessels, trains)

https://tcca.info/documents/2017-february_tcca_hybrid_study_commercial_and_dedicated_networks_for_mcmbb_services.pdf/

TCCA White Papers about Critical Communicationon commercial networks

https://tcca.info/documents/2019-June_TCCA_Public_Safety_Prioritisation.pdf

public safety prioritization on commercial networks• it is forbidden in many countries as it could...

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