OpenAirInterface.org Overview and

Current Status

Mobile Communications Department, EURECOM

LabSoC TelecomParisTech

Plan

Quick overview of OpenAirInterface.org

OpenAir4G LTE implementation

Use-cases of OpenAir4G in collaborative research

Outlook for medium-term

OpenAir4G Overview and Status

www.openairinterface.org

Provides open-source (hardware and software) wireless technology platforms

– target innovation in air-interface technologies through experimentation

– Openair4G – open-source LTE SDR implementation

– Openair0 – innovattion in embedded wireless architectures

We rely on the help of

– Publicly-funded research initiatives (ANR,ICT,CELTIC)

– Direct contracts with industrial partners

– Widespread collaboration with a network of partners using open-source development and tools

LINUX/RTAI based SW development for PCs

LEON3/GRLIB-based HW and eCos/MutexH-based SW development for FPGA targets

LINUX networking environment

– Experimental Licenses from ARCEP (French Regulator) for medium-power outdoor network deployments

1.9 GHz TDD, 5 MHz channel bandwidth

2.6 GHz FDD (two channels), 20 MHz channel bandwidth

800 MHz FDD (two channels) : 10 MHz channel bandwidth

OpenAir4G Overview and Status

Equipment and SW

OpenAir4G Overview and Status

Prototype Equipment Timeline

2003 2004 2005 2006 2007 2008

PLATON/RHODOS

CBMIMOI – V1

AgileRF/Express MIMO

Cellular Systems

Pure Software Radio

WCDMA-TDD

All-IPv4/v6

AdHoc/Mesh and Cellular

Topologies

FPGA-SoC (Virtex 2)

2x2 OFDM(A) @ 2 GHz, 5MHz

channels

Cellular (towards LTE)

Cellular, AdHoc and P2MP

Topologies

FPGA SoC (Virtex 5)+ Interface

for partner Processing Engines

Agile Tuning modules (0.2 – 7

GHz)

Maximum Channel BW 20 MHz

OFDM(A)/WCDMA

2009 2010 2011

ExpressMIMO2

2012 2013

CBMIMOI – V2

Planned replacement

for CBMIMO1

OpenAir4G Overview and Status

ExpressMIMO2 Spartan6 PCIe board

4 LIME microsystems RF ASICs (LTE small-cell eNB/UE

compliant) – TDD/FDD (0 dBm output, 5 dB noise-figure)

PCIe-based acquisition (1-way initially, 4-way possible)

LEON3 embedded system for controlling x86 SDR

External multichannel RF board for LNA/Switch/PA (Summer

2012)

OpenAir4G Overview and Status

Software Roadmap

2003 2004 2005 2006 2007 2008

WIRELESS3G4FREE

OpenAirInterface (WIDENS/CHORIST)

OpenAir4G

TD-SCDMA SDR

IPv6 interconnect

No longer supported

AdHoc/Mesh and Cellular

Topologies

In-house MIMO-OFDMA TDD

waveform (WiMAX 2004 like)

Distributed Signal Processing and

Mesh-Topology functions (L2.5

relaying)

LTE compliant waveform

Mesh extensions from

WIDENS/CHORIST

3GPP-LTE protocol stack

(openair2)

2009 2010 2011

OpenAir.11p

2012 2013

OpenAir4G Overview and Status

OpenAirDAB

OpenAir4G

OpenAir4G Overview and Status

Purpose

Develop an open-source baseband implementation of a subset

of LTE Release-8/10 on top of OpenAirInterface.org SW

architecture and HW demonstrators

Goals

– Representative of LTE access-stratum

Full compliance of LTE frame (normal and extended prefix)

Full Physical Channel compliance (Uplink/Downlink)

Support for a subset of transmission modes (2x2 operation)

Modes 1,2,4,5,6 (Mode 3 to be studied for inclusion)

– Useful for measurement campaigns

– Useful as starting point for research-oriented extensions (to justifiably

claim potential impact on LTE-A)

– Provide realistic (and rapid) LTE simulation environment for PHY/MAC

– Scalable System Emulator target (hundreds of emulated nodes)

OpenAir4G Overview and Status

OpenAirLTE PHY/MAC Protocol Stack (partial

3GPP, openair1, openair2)

Openair1

3GPP Compliance (v8.6)

36-211,36-212,36-213

3GPP Compliance

36-321 (v 8.6)

3GPP Compliance

36-322 Rel-9

PDCP is simplified Rel-9

Linux networking device (IPv4/IPv6, classification/routing

Services for DRB)

OpenAir4G Overview and Status

36-331

ASN.1

messages

Compliance

Subset of LTE-

only

procedures

Current Status (LTE/LTE-A)

PHY (36.211,36.212,36.213) – Compliant LTE softmodem for 5 MHz (20 MHz is next …)

Subset of 36-211,36-212 and 36-213 specifications

Mode 1, Mode 2 and Mode 6 support

Enhanced-Mode 5 and Mode 4 under integration (SAMURAI)

– Missing elements (the rest is largely supported)

User-selected feedback (not planned)

Modes 3,7 (not planned)

Rel-9/10 enhancements (Carrier Aggregation, Modes 8,9) under integration

MAC (36.321)

– Full random-access procedure, Scheduling Request, Buffer Status Reporting

– eNB scheduler is incomplete (to be built per application)

– UE Power headroom

RLC (36.322)

– Complete UM/AM implementation, SRB interfaces with RRC for the moment

OpenAir4G Overview and Status

Current Status

PDCP (36.323)

– Currently just provides DRB interface for linux networking device

– No security and compressions features

– New implementation under integration (PDCP headers, SRB interfaces, opensource ROHC

integration)

RRC (36.331)

– Two separate actions, RRC LITE and Cellular

– LITE

is LTE only, with ASN.1 messages (asn1c C code generator) and subset of LTE RRC

procedures (RRCConnectionRequest/Setup,ReconfigurationRequest)

Empty security context establishment will be added

Currently integrating measurement reporting and MobilityControlInfo (handover)

Extendable for Mesh networks (LOLA)

No SAE NAS support currently, but could be added …

– Cellular

Inherits RRC from W3G4Free (IP/UMTS)

Automatic code generation using Esterel Studio

“hand”-compressed messages and research-oriented NAS extensions for IPv6

interconnect (QoS and mobility management)

OpenAir4G Overview and Status

OpenAir4G Overview and Status

OpenAir4G Use-cases in Experimental

Research

Field Measurements

OpenAir4G Overview and Status

2 Antenna

PA/LNA

Module

Cordes-sur-Ciel (Summer 2010)

SmallCells/MacroCells

(SAMURAI,SACRA FP7)

Low-latency (real-time) backbone network (X2)

Non real-time backbone network (ADSL)

Wireless links for signaling between macro and femto eNb (basestations)

Questions/Issues •how do basestations get synchronized (TDD now, FDD later – LTE-A)? (lack of GPS, lack of sufficient network support) •Spectrum aggregation and management •Over the air inter-basestations links are a mesh topology (relaying, interference, etc.) •How do UEs (terminals) handle interference in single-frequency networks -> dual-antenna receivers + MU-detection

OpenAir4G Overview and Status

Spatio-temporal Signal Processing

(CROWN,SAMURAI – FP7)

Exploitation of reciprocity for interference mitigation

scenarios (CROWN)

Efficient MU-MIMO receivers (SAMURAI)

OpenAir4G Overview and Status

LOLA (FP7): Sensors, M2M/MTC, Traffic,

Latency

17

M2M, Traffic and Latency

M2M communications include but are not limited to

sensory data

– Sensors will surely be a big part and LTE is being dimensioned

for this

– High rate (e.g. surveillance) and low rate (e.g. metering)

– Both may require low-latency, either because

event detection paradigms (high or low rate)

Power consumption in massive sensor deployments (low

rate, low duty-cycle, small packets or even just one analog

sample)

18

Ultimate goal of our work

19

Adapting Radio-Access to Traffic

New traffic sources bring new challenges in

dimensioning radio access

Key aspects

– Fundamental understanding of the underlying traffic sources

Characterization of packet arrival processes and their relationship

to the environment

Nature of the sources: mostly digital but what about analog?

– Mapping on radio-access networks

Impact on PHY/MAC

Interplay between latency, bandwidth and spectral-efficiency

Interplay between latency, bandwidth and energy-efficiency (hard to

model)

20

What about cooperation / collaboration and

feedback

Correlation in traffic sources (analog or digital) will

bring the need for collaborative two-way protocols

for exploiting correlation between nodes

– At PHY (today) SNR improvement and multiuser detection with

random correlated arrivals (event-driven traffic)

– At MAC scheduling paradigms for low-latency with event-driven

traffic

Feedback almost comes for free in networks like

LTE and doesn’t affect the sensors themselves very

much

21

Relaying (LOLA, CONECT, Systuf)

OpenAir4G Overview and Status

UEs

RS1 RS2 eNB

UL Coverage Extension Scenario

exploit distributed signal processing

with relay infrastructure to cover

holes in rural deployments

UL/DL Multiplexing in TDD

Two-hop comm. without rate

penalty => lower UE TX power

Street lamp relay

Relay in Tramway/Train

UEs

RS1

1 3

2 3 3

2

Outlook

openair4G are growing thanks to FP7 / National support

– Industrial partners are making use of the technology (e.g. Alcate-Lucent) for

proof-of-concept LTE-oriented extensions

– Several academic and research find the development useful for research

Teaching/Training Activities

– Willingness to increase our activities in training (both academic and industrial

research) => FP7 Acropolis NoE

Towards a fully-compliant open-source implementation

– Interest in a common framework and/or mutualization of platforms for LTE

experimentation

– EURECOM is working with industrial partners on minimizing the distance

between OpenAir4G and commercial equipment (in particular ALU and

AT4Wireless (Spain))

– Short-term wish: OpenAir4G UE attaching to a commercial eNB

– Medium-term wish: Commercial UE attaching to an OpenAir4G eNB

OpenAir4G Overview and Status

OpenAir4G Overview and Status

Questions? (thanks)