design and implementation of an open source nb-iot enb...irt-bcom ntust university nokia bell labs...

Design and Implementation of an Open

Source NB-IoT eNB

Presenter: Chin-Ya Huang,

National Taiwan University of Science and Technology (NTUST)

National Chiao Tung University (NCTU)

Outline

• Contributing members

• NB-IoT Introduction

• Differences between LTE and NB-IoT

• LTE to NB-IoT on OAI

• Contributions

• On-going Jobs

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Contributing members

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NB-IoT

NTUST UniversityIRT-bcom NOKIA Bell Labs TCL Bologna University

Eurecom

– Current teams:

Contributing members

Bcom

Vincent

Savaux

Matthieu

Kanj

Rodolphe

Legouable

UBologna

Michele Paffetti

Eurecom

Raymond

Knopp

Stephane Paquelet

– Current teams:

Contributing members

NTUST

Ray Cheng Calvin Hsu Nick Ho Eric Hsieh

Kenny Chen Alan Lee Xavier Liu

Vanessa TsaiNikita Hsiao

Gina Lin Asif Ali ZamzamiYaya Huang

Outline

• Contributing members

• NB-IoT introduction

• Differences between LTE and NB-IoT

• LTE to NB-IoT on OAI

• Contributions

• On-going Jobs

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Introduction about NB-IoT

• NarrowBand-Internet of Things(NB-IoT) is a 3GPP cellular

network technology from release 13 for providing IoT services.

• NB-IoT can be deployed “in-band”, normal LTE carrier, or in the LTE

carrier’s guard-band, or “standalone” for deployments in dedicated

spectrum.

• The architecture of NB-IoT is baseed on LTE but with some changes

because of requirement of IoT service.

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Introduction about NB-IoT

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NB-IoT RAN and EPC architecture

EPC

Introduction about NB-IoT

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NB-IoT control plane protocol stack

RRC

PDCP

RLC

MAC

PHY

NAS

RRC

PDCP

RLC

MAC

PHY

S1AP

SCTP

IP

L2

L1

NAS

S1AP

SCTP

IP

L2

L1

Uu S1-CUE eNB MME

Outline

• Contributing members

• NB-IoT introduction

• Differences between LTE and NB-IoT

• LTE to NB-IoT on OAI

• Contributions

• On-going Jobs

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Differences between LTE and NB-IoT

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LTE NB-IoT

Large packet size

High data rate

Large bandwidth

Low delay tolerant

Short battery life

High device cost

High power consumption

Small packet size

Low data rate

Small bandwidth

High delay tolerant

Very long battery life

Low device cost

Low power consumption

V.S.

Differences between LTE and NB-IoT

LTE scheduling Subframe-based scheduling

NB-IoT scheduling NPDCCH Period, NPDCCH period

(PP)-based scheduling

NPDCCH

NPDSCH

NPDCCH

NPDCCH

NPDSCH

NPDCCH

NPDSCH

NPDCCH

NPDSCH

NPDCCH

NPDSCH

NPDCCH NPDSCH NPDSCH NPDSCH

NPUSCH

subframe

(1ms)

NPUSCH NPUSCH NPUSCH NPUSCH

DL/UL

DL

UL

Scheduling concept

Outline

• Contributing members

• NB-IoT introduction

• Differences between LTE and NB-IoT

• LTE to NB-IoT on OAI

• Contributions

• On-going Jobs

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LTE to NB-IoT on OAI

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OAI supported NB-IoT adopts Nokia EPC as NB-IoT EPC.

(cellular IoT control plane optimization, no SCEF)

EPC

Upper PHYNB_TXNB_uespec_RXrx_nprach

MACNB_initiate_ra_proc NB_rx_sdu NB_get_dci_sd NB_get_dlsch_sdu

Process_UL_IND Process_SCHED_REP IF_module

UL_Indication Schedule_Response IF_module

Lower PHYReceiver Transmitter

L2

L1

LTE to NB-IoT on OAI

eNB Job Partition

LTE to NB-IoT on OAI

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OAI L2/L1 architecture

LTE to NB-IoT on OAI

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MAC Layer Modification

• New Scheduling procedure

• Different way to handle available resource

• Different DRX procedure

• New control elements

• Etc.

UuUE eNB

Outline

• Contributing members

• What is OAI

• NB-IoT introduction

• Differences between LTE and NB-IoT

• LTE to NB-IoT on OAI

• Contributions

• On-going Jobs

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Replaceable scheduling algorithm

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Replaceable scheduling algorithm module

MAC Scheduler

• Preprocessor

• Scheduling algorithm

• Can be replaced by developer

• Final scheduling

• Fix procedure for generate the

scheduling result

Replaceable

Replaceable scheduling algorithm

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Replaceable scheduling algorithm module

MAC Scheduler

• Preprocessor

• Scheduling algorithm

• Can be replaced by developer

• Final scheduling

• Fix procedure for generate the

scheduling result

Your algorithm

Scheduler log

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Timing diagram tool

• Show the timing for all transmission and signal

• This tool read log file “schedule_result.txt” then generate the diagram

• “schedule_result.txt” is generated by eNB, developer can fill this file for process timing diagram

22schedule_result.txt

Timing diagram tool

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Timing diagram tool

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Contributions

• OAI NB-IoT Technical Document

– https://goo.gl/rz3rjh

• OAI Technical Feature List

– https://goo.gl/AUn6jF

Testing Status:

• RA Msg3 reception

– B-COM is checking if Msg4 is decodable.

• Integration and testing with EPC25

Tools

Outline

• Contributing members

• What is OAI

• NB-IoT introduction

• Differences between LTE and NB-IoT

• LTE to NB-IoT on OAI

• Contributions

• On-going Jobs

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On-going Jobs

• NB-IoT Testing

– Random access Msg4 decoding

– Integration and testing with EPC

• LTE to 5G on OAI (NTUST, NCTU)

– RAN virtualization on top of M-CORD

– Soft-PHY realization

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M-CORD Architecture

M-CORD (Mobile CORD) enables 5G on CORD to fulfill the

requirement of mobile network.

Disaggregated/Virtualized RAN

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OAI LTE in M-CORD

• CORD is built by NCTU

• Porting vBBU to CORD (compute node of OpenStack)

• NTUST focus on LTE MAC Enhancement

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References

[1] Y.-P. E. Wang, X. Lin, A. Adhikary, A. Grövlen, Y. Sui, Y. Blankenship, J. Bergman,

and H. S. Razaghi, “A Primer on 3GPP Narrowband Internet of Things (NB-IoT),” IEEE

Communications Magazine, vol. 55, no. 3, pp. 117-123, Mar. 2017.

[2] B. Snow, “Mobile CORD (M-CORD) Open Reference Solution for 5G”, 2017, [Online].

Available: http://sites.ieee.org/netsoft2017/files/2017/07/Netsoft2017 Keynote Snow.pdf

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Thank you!

Email: crg@mail.ntust.edu.tw

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