DySPAN 2017 Field Trial of the 3.5 GHz Citizens Broadband Radio Service Governed … · 2019-02-22 · Field Trial of the 3.5 GHz Citizens Broadband Radio Service Governed by a Spectrum

VTT TECHNICAL RESEARCH CENTRE OF FINLAND LTD

Field Trial of the 3.5 GHz Citizens Broadband Radio Service Governed by a Spectrum Access System (SAS)

CORE++ Cognitive Radio Trial Environment Project

http://core.willab.fiPart of the Tekes 5thGear programme and 5GTNF

Marko PalolaVTT Technical Research Centre of Finland Ltd, Oulu, Finland

Marko Höyhtyä1, Pekka Aho1, Miia Mustonen1, Tero Kippola2, Marjo Heikkilä2, Seppo Yrjölä3, Vesa Hartikainen3, Lucia Tudose3, Arto Kivinen4, Reijo Ekman4, Juhani Hallio4, Jarkko Paavola4,

Marko Mäkeläinen5, and Tuomo Hänninen5

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Field trial of the 3.5 GHz CBRS Governed by a Spectrum Access System (SAS)

Contents

1) Introduction2) Spectrum Access System (SAS)3) Field trial4) Performance results5) Conclusions

Marko Palola, VTT Technical Research Centre of Finland Ltd, Oulu, Finland


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§ A field trial of spectrum access system (SAS) based Citizens Broadband Radio Service (CBRS) in the 3.5 GHz band is presented

§ Live LTE-A test network in Finland is used with commercial base stations, LTE Core and Network Management System.

§ Performance measurements carried out

§ Performance analysis of field trial is presented

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Field Trial of the 3.5 GHz Citizens Broadband Radio Service Governed by a Spectrum Access System (SAS)Research motivation

§ On-going standardization and implementation of the specification§ Can we implement SAS using commercially available mobile networks and

equipment?§ Does the real system meet the set time limits when using commercially

available mobile networks and equipment?§ How long it takes to set up LTE-A mobile broadband using dynamical

spectrum? § Are there some ways to speed up the process?

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Contents



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Spectrum Access System (SAS)

§Part of Citizens Broadband Radio Service (CBRS) for shared wireless broadband use of the 3.5 GHz band, an U.S. standard

§Allows dynamic 3-tier sharing in an area § Incumbent, Priority Access License, General Authorized Access

§Environmental Sensing Capability (ESC) and database based operation

§On-going activities by the FCC and the Wireless Innovation Forum.

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Spectrum Access System (SAS)Dynamic Spectrum Sharing

§ Incumbents protected from interference§ PA users protected from interference§ GAAs are not protected§ Band divided to channels, 10MHz each§ GAAs have dedicated channel§ PAL channels available to GAAs if idle § Primary user activity takes 2 channels

Field trial uses 3550-3590MHz, four 10MHz channels 3+1 configuration

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Spectrum Access System (SAS)Reference Architecture

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SAS in an area• Determines available frequencies • Assigns them to different CBSDs • Sets transmission power limitsDomain Proxy• Manages multiple CBSDs• Allows legacy systems to connectIndividual CBSD• Access SAS for shared spectrumEnvironmental Sensing Capability• Detects primary user activity


Contents


Field trial of the 3.5 GHz Citizens Broadband Radio Service Governed by a Spectrum Access System (SAS)

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Field trial: ArchitectureCORE++ http://core.willab.fi/

CORE++ has setup a unique live LTE test

network with commercial 4G/LTE-A

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Field trial: Architecture1) ESC determines availability of shared

spectrum based on collected occupancy information (frequency, bandwidth, power)

2) SAS Repository gathers data about spectrum use and base stations.

3) Domain Proxy and stand-alone base station connect to CBSD Manager for shared spectrum access (REST API).

4) SAS Algorithm for channel allocations and optimizations

5) DP uses NMS to configure the base stations (PA, GAA) accordingly.

6) Stand-alone base station (CBSD-3) provides self-management.

CORE++ http://core.willab.fi/

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Field trial: Radar Sensing System

Radar signal was generated§ Pulse repetition frequency 1 kHz§ Pulse width 0.9 µs§ Antenna scan rate 15 RPM§ Antenna beam width 1.8 degrees

A spectrum sensing device is used to collect the occupancy data. § frequency resolution of 19.531 kHz § Occupancy scan every 45 seconds.§ Signal detection level used -90 dBm


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Field trial: LTE 3.5 GHz network

Three commercially available Flexi Multiradio time-division 3GPP Release 10 (TD)-LTE 3.5 GHz base stations§ 3GPP band 42 (3.4–3.6 GHz)§ Configured to indoor usage, low

power

LTE management system

LTE core network


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Contents



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Performance results : Channel Evacuation

§ Grant to SAS band is given to CBSD, CBSD reports using a heartbeat request.

§ ESC detects a channel notavailable

§ SAS decides to deny the grant§ CBSD gets info on next heartbeat

response.§ CBSD reports channel is freed

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ESC Alert

SASESC CBSD/DP

SAS performs channel

optimisation assessment

Band evacuation and reconfiguration of base stations

SAS continues resource

optimisation

Heartbeat Request

Heartbeat Response

Heartbeat duration expires; Reset

Heartbeat duration timer

Heartbeat Request Heartbeat duration expires; Reset

Heartbeat duration timerHeartbeat Response

(new operational parameters)

Relinquish Request

Relinquish Response

Grant Request

Grant Response

Operation continues with new operational

parameters

Waiting for Heartbeat

Spectrum inquiry request

Spectrum inquiry response

SAS performs channel

availability assessment

Heartbeat Request


Performance results : Reconfiguration time

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§ CBSD/DP is requesting a newchannel from SAS by placing a Grant Request

§ SAS approves or denies theresponse

§ Optional spectrum inquiry to checkavailability of channels

§ CBSD responds with Heartbeats to indicate transmission attempt


Performance results : Measurement points

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T13

T0

Radar sensed to appear

T1 T2

ESC combines sensor information and generates an

ESC Alert

T3

SAS algorithm optimizes the band

allocations

T4

Domain proxy sends commands to NMS according to SAS

algorithm responses

T5

NMS begins configuration of

CBSD

Band is cleared, CBSDs no more

operating in the band

T6 T7

Grant request is sent to SAS

Evacuation time Te

Frequency change time Tw

Td

CBSD Manager sends relevant

information to SAS algorithm

T8

SAS algorithm determines suitable

band and radio parameters for

operation

Transmission Td

T9

Grant response is sent to CBSDs

Te

T10

Heartbeat NMS begins configuration of CBSD

T11 T12

Tw

Operation continues in a new band

Heartbeat


Performance results : Evacuation perf. results

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Performance results : Reconfiguration time, the results

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Contents



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ConclusionsAnalyzed time domain operation in a practical SAS based CBRS system§ The most time-consuming phases in the evacuation and reconfiguration

process are base station configuration: locking/unlocking/changing freq

FCC operational rules were met in the field trial§ Evacuation is confirmed within 300 seconds from detection of incumbent§ CBSD/DPs must comply with SAS commands within 60 seconds

Improvements (up-to 70%): support fast on-air frequency changes.Large scale : NMS emergency plans to evacuate large networks

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VTT TECHNICAL RESEARCH CENTRE OF FINLAND LTD

The First End-to-End Live Trial of CBRS with Carrier Aggregation Using

3.5 GHz LTE EquipmentFor further information, please visit

the CORE++ project website:http://core.willab.fi

Project Manager: [email protected]

Documents

DySPAN 2017 Field Trial of the 3.5 GHz Citizens Broadband Radio Service Governed … · 2019-02-22 · Field Trial of the 3.5 GHz Citizens Broadband Radio Service Governed by a Spectrum