SimuLTE Tutorial Antonio Virdis University of Pisa - Italy - - PowerPoint PPT Presentation

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SimuLTE Tutorial Antonio Virdis University of Pisa - Italy - - PowerPoint PPT Presentation

Oct 17, 2023 416 likes •755 views

SimuLTE Tutorial Antonio Virdis University of Pisa - Italy Simulating device-to-device communications in OMNeT++ with SimuLTE: scenarios and configurations Giovanni Nardini, Antonio Virdis, Giovanni Stea University of Pisa - Italy Antonio

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SimuLTE Tutorial

Antonio Virdis

University of Pisa - Italy

Antonio Virdis - SimuLTE 2016 1

Simulating device-to-device communications in OMNeT++ with SimuLTE: scenarios and configurations

Giovanni Nardini, Antonio Virdis, Giovanni Stea University of Pisa - Italy

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Outline

  • LTE Context
  • Simulator structure
  • Examples
  • LTE
  • LTE-Advanced
  • Towards 5G: D2D

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SLIDE 3

LTE

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UE 1 UE 2 UE 3 eNb

Scheduling Data Req Channel Quality

1ms

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SLIDE 4

LTE

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eNb

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SimuLTE

  • OMNeT-based system-level simulator of LTE networks
  • Focused on testing algorithms for resource scheduling at large scale
  • INET based
  • Built as an additional NIC interface
  • Follow the evolution of cellular communications

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SLIDE 6

Nodes

eNB UE

UE

IP UDP TCP UDP apps TCP apps LTE NIC

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Standard Hosts

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SLIDE 7

Layering

PDCP RLC MAC PHY

LTE NIC

PDCP RLC MAC PHY

SimuLTE

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UE

IP UDP TCP UDP apps TCP apps LTE NIC

1ms

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SLIDE 8

Common Structure: Inheritance

Base NIC eNB NIC UE NIC

Base RLC eNB RLC UE RLC Base MAC eNB MAC UE MAC Base PHY eNB PHY UE PHY Antonio Virdis - SimuLTE 2016 8

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Goal: algorithms

  • Aim at implementing and testing resource-scheduling algorithms
  • Model resources.
  • Model resource management
  • Provide an API to users

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SLIDE 10

Tx/Rx modeling

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UE eNB frequency

1 ms

OFDM

K bit

RB CQI

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SLIDE 11

Scheduling

AMC User Tx Params Pilot Scheduler Allocator Scheduling Policy

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N bit

Available Data UE Reports Schedule List

M bit

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Scheduling Hierarchy

  • Scheduler Type and
  • Scheduling Policy

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eNB Scheduler eNB Scheduler UL eNB Scheduler DL Scheduling Policy MAX C/I PF DRR

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Example 1: ~2010 rel 8-9

  • Simple network
  • Common parameters
  • Mobility
  • Application type
  • SimuLTE Parameters
  • Number of RBs
  • Scheduler type

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Example 1: ~2010 rel 8-9

**.nic.phy.channelModel = xmldoc("config_channel.xml") **.mac.schedulingDisciplineDl = "MAXCI"

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# connect each UE to the eNB **.ue[*].macCellId = 1 **.ue[*].masterId = 1

Association

**.deployer.numRbDl = 6 **.deployer.numRbUl = 6

# Resources

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Custom Scheduling

  • Inherit a scheduling policy (LteScheduler Class)
  • Two stages scheduling
  • Prepare schedule list
  • Commit schedule list

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Policy 1 Policy 2 Policy 3 Schedule list

Scheduling Policy MAX C/I PF DRR

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SLIDE 16

Example 2: ~2013 rel 10-11

  • LTE-advanced
  • Multiple cells
  • CoMP techniques
  • X2 Communication
  • Heterogeneous Networks
  • Dense Networks

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Example 2: ~2013 rel 10-11

<parameter name="multiCell-interference" type="bool" value="true"/>

In config_channel.xml

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**.ue1*.macCellId = 1 **.ue1*.masterId = 1 **.ue2*.macCellId = 2 **.ue2*.masterId = 2 **.ue3*.macCellId = 3 **.ue3*.masterId = 3

Association

**.eNodeBTxPower = 40

Transmission Power

Interference? Coordination! (CoMP)

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Allocation Flexibility

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Scheduling Policy Allocator

getBlocks(n)

Scheduling Policy Allocator

getBlocks(n,limit)

Joint Scheduler / Allocator

USER FRIENDLY FLEXIBILITY

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External Cells: lightweight eNBs

*.numExtCells = 2 #============= Configuration ============ *.extCell[*].txPower = 20 *.extCell[*].txDirection = "ANISOTROPIC" *.extCell[*].bandAllocationType = "RANDOM_ALLOC" *.extCell[*].bandUtilization = 0.5 #============= Positioning ============ *.extCell[0].position_x = 100m *.extCell[0].position_y = 600m *.extCell[0].txAngle = 315 *.extCell[1].position_x = 600m *.extCell[1].position_y = 600m *.extCell[1].txAngle = 225

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Example 2: ~2013 rel 10-11

LTE NIC PHY MAC RLC PDCP X2 Manager

X2 User X2 User

...

to/from IP to/from LteX2App[]

**.x2Enabled = true *.eNodeB*.numX2Apps = 2 *.eNodeB*.x2App[*].server.localPort = 5000 + ancestorIndex(1)

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X2

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Example 3: NOW towards 5G

  • Infrastructure vs D2D
  • Multicast or Unicast
  • Scheduling remains under control
  • f the eNB
  • UEs still need to request resources

to the eNB

  • Enables frequency reuse

Internet UE1 UE2 eNodeB UL DL UE3 UE4

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Data Flow

  • Data in the UL direction travels

the whole stack

  • Segmentation/concatenation
  • Error control
  • It follows a reverse path during

reception

  • D2D is given a separated path

Channel Model

PDCP RLC MAC PHY

HARQ HARQ

HARQ UL UL D2D

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D2D: one-2-one

  • Enabling D2D
  • AMC mode: D2D
  • Peering relation
  • Static peering
  • Dynamic peering not available
  • Channel measurement
  • Dynamic
  • Static

1 # enable D2D capabilities 2 *.eNodeB.d2dCapable = true 3 *.ueD2D*[*].d2dCapable = true 4 # select the AMC mode 5 *.eNodeB.nic.mac.amcMode = "D2D" 6 # set peering relationship 7 *.ueD2DTx[0].nic.d2dPeerAddresses= "ueD2DRx[0]" 8 # select the CQI for D2D transmissions 9 *.eNodeB.nic.phy.enableD2DCqiReporting = true 10 **.usePreconfiguredTxParams = false 11 # set Tx Power 12 *.ueD2DTx[0].nic.phy.ueTxPower = 26 # in dB 13 *.ueD2DTx[0].nic.phy.d2dTxPower = 20 # in dB

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Simultaneous Transmissions

  • Transmitting UE can reuse the

same frequencies

  • Interference between pairs can
  • ccur
  • Infra or D2D? [Switch?]
  • Decide if 2 pairs can transmit

simultaneously

2 3 4 5 6 7 9 8

Algorithms

Resource Scheduling Mode Selection

?

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Data TX/RX

  • Data is sent in unicast
  • Interference is broadcast
  • Infra: each used RBs is tagged with

the ID of a UE

  • D2D: each RB has a list of the UEs’

IDs

  • SINR is computed taking

interference into account

RBs

UE1 UE4 UE5 UE1 UE5 UE2 UE3

1

2 3 4 5

UE1

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Mode selection: custom algorithms

  • Read status
  • Decides whether to switch or not

D2DModeSelection … doModeSelection()=0 ... D2DModeSelectionBestCqi … doModeSelection() { … } ... ... … doModeSelection() { … } ...

...

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D2D: multicast

  • Predefined CQIs only

<multicast-group hosts="ueD2D[*]" interfaces="wlan" address="224.0.0.10"/> *.ueD2D[0].udpApp[*].destAddress = "224.0.0.10" # select the CQI for D2D transmissions *.eNodeB.nic.phy.enableD2DCqiReporting = false **.usePreconfiguredTxParams = true **.d2dCqi = 7 # set Tx Power *.ueD2DTx[0].nic.phy.ueTxPower = 26 # in dB *.ueD2DTx[0].nic.phy.d2dTxPower = 20 # in dB

eNB

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Controlling the TX Range

UE3 UE4

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**.d2dCqi = 7 # set Tx Power *.ueD2DTx[0].nic.phy.ueTxPower = 26 # in dB *.ueD2DTx[0].nic.phy.d2dTxPower = 20 # in dB Larger range Lower data rate Smaller range Higher data rate

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D2D: layering and new modules

  • An additional data path
  • No HARQ
  • Send Broadcast

PDCP RLC MAC PHY

UL D2D D2D MULTI HARQ ChannelModel

sendUnicast() sendBroadcast()

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Further Developments

  • Handover (actually released)
  • Native support to Veins
  • Moving towards 5G
  • CRAN deployments
  • Mobile Edge Computing applications

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Conclusions

  • SimuLTE: focused on resource scheduling
  • Modeling
  • Layering
  • Resources
  • Scheduling
  • Case studies
  • Simple LTE network
  • LTE Advanced
  • D2D communications towards 5G

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Thanks for your attention

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