OpenAirMeshA Platform for Cooperative Mesh Networks

H. Anouar, C. Bonnet,F. Kaltenberger, R. Knopp

GDR ISIS Meeting

Paris, 12.6.2008

Introduction to OpenAirInterface

Development platform for digital radio communicationsOpen-source hardware and software solutionInnovation through experimentationCellular and Mesh configurationPHY layer targets WiMax and UMTS LTE (MIMO-OFDM)MAC layer supports collaboration

Hicham Anouar et al. www.OpenAirInterface.org 2/12

Wireless Mesh Network Architecture

Nodes can take the role of a CH or MRDynamical self-organization and self-configuration

Hicham Anouar et al. www.OpenAirInterface.org 3/12

Cooperation in Wireless Mesh Networks

Types of CooperationCollaborative ressource allocation (spatial re-use)RelayingDistributed signal processing

BenefitsIncreased network throughputIncreased coverage and reliability

Enabling TechnologiesDistributed synchronizationInterference-aware schedulingMultiple antennas (MIMO)Interference cancellation receivers

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Hardware Architecture

CBMIMO1 card UE antennas BS antennas

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Hardware Characteristics

Currently Next YearCarrier Freq. 1.90 - 1.92 GHz 200 MHz - 7.5 GHzBandwidth 5 MHz 20 MHzChannels 2 4Duplex TDD TDD and FDD

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Physical Layer

Reconfigurable MIMO-OFDMAOrthogonal pilot channelsFeedback channelsDistributed network synchronizationBit interleaved coded modulation (BICM),turbo and convolutional codes, hybrid ARQSpatial multiplexing (point-to-point or distributed MIMO)Successive interference cancellation (SIC) receiver 1

1R. Ghaffar and R. Knopp, “A MIMO broadcast strategy and interferencecancellation in single frequency cellular system,” in Proc. 1st COST2100 Workshop onMIMO and Cooperative Communications, Trondheim, Norway, Jun. 2008.

Hicham Anouar et al. www.OpenAirInterface.org 7/12

Distributed Network Synchronization

CH1 CH2

MR

CHSCH1 CHSCH2

MRSCHMRSCH

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Layer 2 Protocol Stack

Cluster-Head

Mesh Router

Isolated Node

Edge Router

Other Access Technology

Responsible for MAC and PHY layer resource allocationInterconnection of secondary air interfaces.

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Layer 2 Components

Media Access Control

(MAC)

Radio Resource Control

(RRC)

PDCP

Physical/Abstraction Layer

(PHY)

PDCPConfig

RLCConfig

MACConfig Measurements

LogicalChannels

SignallingRadioBearers

Non Access-Stratum Driver

(networking device interface)

TransportChannels

Radio Link Control

(RLC)

Non-access stratum (NAS) drivernetworking device interfaceprovides IP/MPLS layerservicesresponsible forrouting/forwarding

Radio resource controller (RRC)MAC layer signallingRetrieval of measurementinformation

Convergence protocol (PDCP)IP interfaceheader compression, ciphering

Hicham Anouar et al. www.OpenAirInterface.org 10/12

Layer 2 Components

Media Access Control

(MAC)

Radio Resource Control

(RRC)

PDCP

Physical/Abstraction Layer

(PHY)

PDCPConfig

RLCConfig

MACConfig Measurements

LogicalChannels

SignallingRadioBearers

Non Access-Stratum Driver

(networking device interface)

TransportChannels

Radio Link Control

(RLC)

Radio link controller (RLC)automatic repeat requestprotocols (ARQ)IP/MPLS packet segmentation

Media access controller (MAC)scheduling and multiplexingmapping between logical andtransport channels

Physical/Abstraction LayerPHY layer can also beemulated

Hicham Anouar et al. www.OpenAirInterface.org 10/12

Cooperative Protocols in OpenAir L2

Advanced measurement support for L3 routing protocolsNodes in mesh dynamically inform L3 of wideband channelquality with their neighborsL3 routing can use these measurements to adapt routing inmesh (relay selection based on QoS)

Hicham Anouar et al. www.OpenAirInterface.org 11/12

Cooperative Protocols in OpenAir L2

Support for QoS scheduling for MR-CH and MR-MRcommunication within cluster

CH scheduler uses low-layer feedback of wideband spatialchannel quality and L2 queuing information to schedulePHY/MAC resources in the cluster.Measurements combined with dual-antenna interferencecancellation receivers can be used to achieve spatial reusewithin the cluster with scheduling

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Cooperative Protocols in OpenAir L2

Outlook: Support for L1 cooperative communications(decode-and-forward) based on distributed MIMO-HARQ

Main problem: How does the MAC identify flows which arerouted by L1 (as opposed to L3) in a collaborative sense

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Applications and Conclusions

Cooperative Wireless Mesh Networks can be used forRapidly deployable networks for public safety units2

Sensor networks for cognitive radio3

OpenAirMesh providesOpen-source hardware and software platformCooperative MAC and PHY LayerDistributed network synchronization

2www.chorist.eu3www.sendora.eu

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