cbrs alliance release 3 specification webinar

CBRS Alliance Release 3 Specification Webinar15 April, 2020

Welcome

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CBRS Alliance Copyright © 20202

Speaker Introduction

Dr. Gary Boudreau, System Architect at Ericsson, CBRS Alliance Coexistence Workgroup Chair

Dr. Gary Boudreau is an LTE/NR System Architect at Ericsson and CBRS Alliance Technical Workgroup Chair. Dr.

Boudreau is a professional engineer with over 25 years of communications system engineering experience spanning

cellular wireless communications, satellite communications and military systems.

Dr. Masoud Olfat, Sr. Director of Technology Development at Federated Wireless, CBRS Alliance Network

Services Workgroup Chair

Dr. Masoud Olfat is the Sr. Director of Technology Development at Federated Wireless and CBRS Alliance Network

Services Workgroup Chair. Dr. Olfat is a senior technologist and researcher with over 20 years of experience driving

innovative technology strategies and solutions for telecom corporations such as Nextel, Sprint Nextel, Clearwire,

LightSquared, Federated Wireless, and University of Maryland.


Speaker Introduction

Iwajlo Angelow, Senior Standardization Specialist at Nokia, CBRS Alliance Radio Workgroup Chair

Iwajlo Angelow is the Senior Standardization Specialist at Nokia and CBRS Alliance Radio Workgroup Chair. He has

over 15 years of experience in mobile communications R&D and has been a 3GPP RAN4 attendee since 2005. He has

been Rapporteur of various spectrum related Work Items in 3GPP including Band 48 and n48.

Dr. Yi Hsuan, Google Access Wireless System Engineer at Google, CBRS Alliance Coexistence Workgroup

Chair

Dr. Yi Hsuan is a wireless specialist in Google with more than 20 years of experience in the industry of wireless

communications. He is currently working on system requirements and protocol standardization in the Wireless

Innovation Forum and the CBRS Alliance to enable spectrum sharing.


Agenda

• Welcome and Introduction – Alan Ewing, CBRS Alliance Executive Director

• Specification Overview: Gary Boudreau (Ericsson), Chair of CBRS Alliance

Technical Work Group – 5 min

• Release 3 Radio Requirements: Iwajlo Angelow (Nokia), Chair of the Radio

Task Group – 5 minutes

• Release 3 Coexistence: Yi Hsuan (Google), Chair of Coexistence Task

Group – 20 min

• Release 3 Network Architectures: Masoud Olfat (Federated Wireless), Chair

of Network Services Task Group – 20 min

• Q&A – 10 min


Q&A

• Best to leave Q&A to the end to ensure we have time to cover all material.

Use the question function in the webinar platform to submit questions during

the session. Will try to address clarification questions in real-time, but

general questions will be handled after presentations.


CBRS Alliance Technical Overview

Gary Boudreau, TWG Chair

Overview

• CBRS Alliance is an industry forum created to champion LTE and

NR in the CBRS Band (3550-3700 MHz) in accordance with FCC

Part 96 Rules

• Information on FCC Part 96 can be found at:

– The Part 96 rules can be found at: https://www.ecfr.gov/cgi-bin/ECFR,

select Title 47, Chapter 1, Volume 5, Part 96

– WInnForum webinar: Understanding the New US 3.5 GHz Band at:

https://www.youtube.com/watch?v=lQ2a4ZRjGgE&t=304sNote: This Webinar is from June 2015 and a couple of the FCC rules have since been

revised, but webinar remains an excellent overview. WInnForum has additional Webinars on

CBRS available on youtube.


https://www.ecfr.gov/cgi-bin/ECFR

https://www.youtube.com/watch?v=lQ2a4ZRjGgE&t=304s

WInnForum and CBRS Alliance

WInnForum

• Official SDO with multiple committees

• Spectrum Sharing Committee (SSC) handles

FCC Part 96 rules (CBRS) & working closely

with US Government

• Technology Neutral (many members support

LTE, but other members including WISPA

support proprietary technology use in the band)

• Developing SAS, CBSD & ESC requirements;

Security methods; SAS-CBSD & SAS-SAS

protocols; Certification tests for: CBSD & SAS

• Specific tools and messages enabling

coexistence across multiple technologies in

WInnForum Release 2

CBRS Alliance

• Focus on LTE and NR technology in the CBRS Band. Builds upon and compliant with WInnForum Standards

• Developing technical specs to support LTE and NR deployments of Private Networks, Neutral Host Networks, Multi-Service Operator Networks, etc.

• Focus on LTE and NR coexistence

• Addressing LTE and NR (5G) commercialization, business and marketing issues

• Broad range of members: manufacturers, operators, verticals and more

• NR functionality standardized in Release 3


Technical Work Group

• Outputs:

– Specifications, best practices, recommendations, guidelines, etc

• Published Technical Specifications can be found from web site: https://www.cbrsalliance.org/

– Contribute into other fora as appropriate (working with WInnForum, ATIS, MulteFire, Small Cell Forum, HTNG and 3GPP)

• Task Groups

– Coexistence TG

– Network Services TG

– Radio TG

– Home Network Identifier TG

Technical WG

Network Svcs TG

Coexistence TG

Radio TG HNI TG


https://www.cbrsalliance.org/

CBRS Alliance builds upon established LTE and NR standards

• 3GPP developed the 3GPP E-UTRA LTE as well as NR (Radio Access Network) requirements and the corresponding network Global Standards

– 3GPP developed hundreds of standard features for LTE and EPS and leverages and/or references many other industry standards (IETF, ITU, OMA, NIST, ETSI, Smart Cards, GPS, and many more)

• US Telecom systems must also comply with relevant FCC Rules and various ATIS Standards (Mobile Alerting, E911, etc)

• CBRS networks must also comply with WInnForum requirements (which include FCC Rules) and we layer on CBRS Alliance specifications

• We are exploiting the strengths of multiple standards bodies to develop a commercial LTE and NR solution in the CBRS Band.

• Release 3 is an instantiation of 5G using NR functionality.


What makes CBRS different?

• LTE and NR are designed for mobile network operators deploying in exclusive use spectrum.

• CBRS is lightly licensed shared spectrum, and opens opportunities for new use cases not addressed by 3GPP (e.g. Neutral Host Networks)– Also defining use of a shared CBRS HNI

– Device Based Authentication

– Multi-services operator deployments

– And more


CBRS Alliance Specifications

• Visit the CBRS Alliance website to see all Release 1,

Release 2 , Release 3 and Independent Specifications

– https://www.cbrsalliance.org/specifications/

• Previous Webinar Recordings:

– CBRS Shared HNI Webinar (Link)

– CBRS Alliance Release 1 Specifications (Link)

– CBRS Alliance Release 2 Specifications (Link)


https://www.cbrsalliance.org/specifications/

https://www.cbrsalliance.org/resource/cbrs-shared-hni-webinar/

https://www.cbrsalliance.org/resource/webinar-cbrs-alliance-technical-specifications-for-networking-coexistence/

https://www.cbrsalliance.org/resource/webinar-cbrs-alliance-technical-specifications-for-networking-coexistence/

Radio Release 3 Updates

Iwajlo Angelow, RTG Chair

Radio TG

• 3GPP has introduced new NR band n48 (RP-190908)

– Channel bandwidth up to 100MHz (see more details below)

– 15 & 30kHz channel raster

– 30kHz sync raster

• 3GPP Rel’16 work on Band 48 and n48 combinations

– LTE inter-band CA, EN-DC, NR intra-band and inter-band CA

NR

Band

SCS

kHz5 MHz 10 MHz 15 MHz 20 MHz 40 MHz 50 MHz 60 MHz 80 MHz 90 MHz

100

MHz

n48

15 Yes Yes Yes Yes Yes Yes1

30 Yes Yes Yes Yes Yes1 Yes1 Yes1 Yes1Yes1

60 Yes Yes Yes Yes Yes1 Yes1 Yes1 Yes1Yes1

Note 1: This UE channel bandwidth is applicable only to DL


Coexistence Release 3 SpecificationYi Hsuan, CTG Chair

What’s New in Rel-3 Coexistence Specification

• Support of 5G NR– Includes CBSDs using NR in the coexistence framework

– How LTE and NR CBSDs coexist in the CBRS band

– GAA channel assignment for NR CBSDs

– CxM-CBSD protocol extension to support NR CBSDs

• More flexible use of TDD configurations– Indoor CBSDs have more flexibility to choose TDD configurations


NR-TDD CBSD Synchronization

• All NR-TDD CBSDs shall derive the same frame timing

as LTE-TDD CBSDs

– Time reference: A time reference traceable to a common

synchronization source. Temps Atomique International (TAI) shall

be used.

– SFN init time: The use of a common SFN initialization time

serves to align the frame boundaries, and indeed the subframe

boundaries, within the required timing accuracy.


TDD Configurations for NR-TDD CBSDs

• NR subcarrier spacing of 30 kHz is supported (15 kHz to

be added in Release 3.1 Coexistence TS)

• All NR-TDD CBSDs in a CBRSA CxG shall support two

uplink-downlink configurations that corresponds to two

mandatory LTE-TDD configurations

• All CBSDs (LTE-TDD or NR-TDD) in a “TDD

configuration connected set” need to use the same or

equivalent TDD configurations


Mandatory NR-TDD UL/DL Configurations

NR-TDD Subframe ‘F’ Symbol Pattern for the CBRSA CxG(equivalent to LTE-TDD special subframe configuration 7)

Mandatory NR-TDD UL/DL Configurations for the CBRSA CxG

UL:DL ratio Slot Number

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

4:5 D D D F U U U U D D D D D F U U U U D D

2:7 D D D F U U D D D D D D D F U U D D D D

Equivalent to LTE TDD configuration 2

Equivalent to LTE TDD configuration 1


Selection of TDD Configuration by the Coexistence Manager

• Creation of TDD Configuration

Connected Set. An “edge”, denoted by a

line in the graph, is created between two

CBSDs, each represented as a vertex in

the graph, if their coverage contours (-

96dBm/10 MHz) overlap with each other.

• All LTE-TDD CBSDs and NR-TDD

CBSDs that are part of the same TDD

Configuration Connected Set shall use

the same or NR Equivalent TDD

configuration.


TDD Configurations for Indoor CBSDs

• Some indoor use cases require higher bandwidth in the uplink, e.g.,

security camera, internet of things, etc.

• Traditional internet service provides more bandwidth in the downlink.

• Mandating the same TDD configuration in a connected set may

exclude some important use cases of CBRS.

• Indoor deployment guidelines are to be published and indoor

CBSDs are allowed to opt out of TDD configuration connected sets.

• The CxM will request Indoor CBSDs to employ the mandatory TDD

Configurations if harmful interference originated by the Indoor

CBSDs is reported.


Deployment Recommendations for Indoor-Indoor and Indoor-

Outdoor Coexistence

• To minimize interference between CBSDs of different networks, the

minimum recommended distance between CBSDs of different

operators is 20 m.

• For scenarios where the distance criteria cannot be met, isolation

between CBSDs of different networks should be larger than 81 dB.

• Isolation measurements between CBSDs not meeting the distance

criteria should be performed to demonstrate the isolation

requirement can be met for any pair of inter-operator CBSDs.

• Operators are encouraged to coordinate deployment prior

installation with assistance from the coexistence manager.


New SAS-CBSD Protocol Extensions

• New information from CBSD to CxM includes

– NrTddConfig: NR TDD configuration information that the CBSD uses or

prefers using

– EutraTddConfig: redefinition of E-UTRA signal information to include NR

equivalent TDD configuration information

– EutraInfo: redefinition of E-UTRA signal information to include NR signal

information

– indoorCbsdOptOut: indication by indoor CBSDs intending to opt out of

TDD configuration connected sets

• New grouping objectives and parameters defined in WInnForum Release 2

specifications will be incorporated in Release 3.1 Coexistence TS


GAA Channel Assignment for NR CBSDs

• NR CBSDs and LTE CBSDs are treated the same by the

CxM in terms of GAA channel assignment for

coexistence.

• CxM shall assign NR CBSDs at least 10 MHz of

contiguous spectrum.

• Specification of PAL coexistence is currently in

development as a Release 4 work item.


Network Services Release 3 Specs

Masoud Olfat, NSTG Chair

NSTG Release 3 Work/Study Items

• Recap from Release 2

– CBRS systems using LTE need IMSI blocks to identify UIM cards, cells/eNodeB

etc.

– USA has only 700 unique IMSI blocks.

– CBRSA arranged to share one block (HNI 315-010) among all CBRS operators

that don’t have their own full-sized blocks.

– 10,000 sub-IMSI-blocks with 100,000 unique IMSI each created.


NSTG Release 3 Work/Study Items

• Network Architecture– 5G NR NSA: Based on 3GPP R15 EN-DC (Option 3)

o LTE and NR in CBRS band

o LTE in non-CBRS band and NR in CBRS band.

– Roaming (Between LTE networks with either or both PLMN using CBRS PLMN ID)

• Data Roaming

• IMS Roaming

– LBO (Local Break-Out)

• Extended Authentication – 5G NR NSA deployment

• Review 3GPP R15 EAP-TLS, as a primary authentication method other than EAP-AKA’, and

define EAP-TTLS

– Credentials Management (EACM) capabilities for CBRS-A

• Dynamic management of Subscriber Credentials (i.e., provisioning, renewal, replacement, and

revocation) is a complex task that has not been tackled in 3GPP/Cellular network.

• CBRS-A Release 3 implements the use of the Extended authentication channel (EAP) to enable

and simplify subscriber credentials management.


5G NR NSA CBRS Network

Architecture (Rapporteur: Orlett Pearson, Nokia)


5G NR NSA Architecture

• UE employing EUTRA-NR Dual Connectivity (EN-DC).

• 5G NR NSA deployment

– U-Plane connection from eNB to EPC,

– U-Plane connection from gNB to EPC.

• Example here:

– the Secondary Cell Group (SCG) bearer has a U-Plane connection

between 5G NR gNB and the core network,

– another U-Plane connection between the LTE eNB and 5G NR gNB to

enable SCG split bearer.

• Other Salient Points from 3GPP R15

– No support for CSG (Closed Subscriber Group)

– No support for EN-DC with MeNB as a CSG cell

– 3GPP will support Private, and Neutral Host Networks beyond Release-

15 for NR SA deployment.

• The EMM cause used for ATTACH REJECT, TRACKING

AREA UPDATE REJECT and SERVICE REJECT by a CBRS

network’s EPC is changed to Cause #15


Roaming in Shared HNI based CBRS

Networks • Data (Rapporteur: Rajesh Kaliaperumal, Ruckus)

• IMS (Rapporteur: Amarendar Sirikonda, Comcast)

• LBO (Rapporteur: Dr. Fabio Giust, Athonet)


Network Architecture: CBRS Roaming

• SHNI CBRS based Private and Hybrid networks may enter into Roaming business

agreements with other Service Providers

• Scenarios Covered

– Subscribers belonging to one CBRS network roams to another CBRS network and both

networks deployed using shared HNI

– Subscribers belonging to CBRS Network operator using Shared HNI roams into another LTE

network that does not use Shared HNI.

• Scope of Work– At VPLMN,

• Authentication Procedure: Locating HPLMN HSS when HPLM is based on Shared HNI.

• PDN Service Resolution: Resolving APN when HPLMN is based on Shared HNI

– At HPLMN,

• Resolving VPLMN when VPLMN ID is based on Shared HNI

• Services Covered– Data Roaming

– IMS Roaming



• Authentication Procedure– DSC (DIAMETER Signaling Controller)

function can be used (on the S6a interface)

– DSC maintaining the mappings of known

IBNs (IMSI Number Block) to the

corresponding Diameter destination realms

or hosts of the destination network

– DSC determine the HPLMN based on IBN

(IMSI Number Block)

• Access Point Name Resolution for Home Routed PDN Connections– home PGW based on Access Point Name FQDN (APN-FQDN) resolution process by DNS,

derived from an APN consisting APN NI and an APN OI.

– APN OI for SHNI CBRS Network is the same for many different networks using the SHNI, so the

default APN-FQDN construction will not be able to provide uniquely identifiable home PGW.

– Proposed Solution:

• The default APN construction format is “APN= <APN-NI>.mnc<MNC>.mcc<MCC>.gprs” where the APN OI

uses the SHNI in the domain mnc<MNC>.mcc<MCC>.gprs.

• HSS to use APN-OI Replacement field to add additional unique identifier of the home network:

<unique_identity>. mnc<MNC>.mcc<MCC>.gprs


IMS-Based Roaming

• Support for IMS-based services (VoLTE, SMS over IMS), in SHNI CBRS Network– roam out of home CBRSA network, into Visited Network provided by an MNO that does not use the SHNI or a

CBRS Network Operator that uses the SHNI.

– Limitation from the use of SHNI to route IMS-based services for visiting subscribers.

– IMS-based services roaming is described in the scenario of a Visited Network that operates as a NHN.

• Roaming for IMS Services– Same roaming procedures as for data for SHNI device roaming on visited network while using IMS services.

– limited to S8-Home Routing option.

– all the IMS functions are in the home network.

• Other IMS service roaming options (LBO-HR and LBO-VR) where some of IMS functions are in the visited network are FFS.



• VPLMN Identity Resolution by HPLMN, when VPLMN is SHNI based CBRS Network, – During the initial Attach, VPLMN MME sends User Location Information (ULI) attribute in the “Create Session

Request”, extracting TAI and TAC

– HPLMN derives the identity of the VPLMN Operator using the IBN portion of the TAC.

• Summary– Roaming and NHN: Roaming architecture can be applied in CBRS NHN when a roaming agreement exists

between PSP and another SP.

– Data and IMS roaming adopts 3GPP defined S8-HR architecture. IMS-Roaming is FFS


LBO in CBRS

• With LBO, UE traffic associated to a single

PDN or multiple PDN connections can be

offloaded to Visited networks, using Local

Gateway function, including– SGW-LBO for partial offload of the data traffic

associated to the same APN, as well as the UE

traffic associated to a single PDN connection.

– S/PGW enables traffic offload for a whole APN, that

is, for all traffic flows associated to such APN.

• LBO is available to UEs accessing the network using any of the access modes

allowed by the CBRSA specifications.

• It is the SP’s responsibility to authorize and select the traffic to be broken out,

regardless if the local network and applications belong to the SP or not.


Extended Authentication Support in

CBRS with NR

(Rapporteur: Dr. Tao Wan, CableLabs)


5G NR NSA Extended Authentication

• In 5G NR NSA EN-DC deployment

(option 3), the extended

authentication is handles in LTE

EPC,

• no change is envisioned in CBRSA

Rel 3

• Key Derivation– for EN-DC, the MeNB generates

and sends S-KgNB to the SgNB from

which KSgNB-UP-enc, KSgNB-RRC-int and

KSgNB-RRC-enc are then derived. The same

derivation of S-KgNB and the subsequent

keys also occurs at the UE side.

UE eNodeB MME AAA

1. RRC Connection Establishment

2. Initial NAS message (Attach/TAU) 3. Start EAP

EAP over NAS EAP over Diameter/Radius

KASME

Delivered via EAP/Success


Extended Authentication Credential

Management (Rapporteur: Dr. Max Pala CableLabs)


Extended Authentication: Credential Management in CBRS-A

• CBRS-A provides the possibility to authenticate users and devices by using different types of credentials (SIM and/or Certificates)

• CBRS-A provides the possibility to register and automatically renew device credentials by leveraging the EAP-CREDS protocol even before providing IP connectivity

• CBRS-A uses the Simple Provisioning Protocol from EAP-CREDS to provide an EAP-based identity management point of integration

– Management does not require additional connectivity

– The Operator’s credentials management system can be implemented directly at the AAA server or proxied to be interfaced with internal or external provisioning systems

• Most of the credential’s management is accomplished with only 2 or 4 messages

• The credentials management system can work with different types of credentials (i.e., X.509 certificates, username & passwords, SIM-based credentials) and, if supported by the UE, allows for switching between different types


Benefits/Advantages

• CBRS-A uniquely provides flexible credential management without compromising security and usability

• CBRS-A also enables new clients with the possibility to provide authorization information if and when registration (or an initial authorization) information is required to gain access to the network (e.g., often referred to as device onboarding)

– Allows for easy bootstrapping mechanism(s)

• When compared to other environment, CBRS-A implementation provides a series of powerful advantages

– Does not require service discovery

– Does not require device certificates on devices

– Does not require IP connectivity

– Provides a full life-cycle credentials management


Q&A

Any Questions?

Thank You!Questions can be sent to [email protected]


mailto:[email protected]

cbrs alliance release 3 specification webinar

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