SimuLTE – A Modular System-level

Simulator for LTE/LTE-A Networks

based on OMNeT++

Antonio Virdis

Giovanni Stea

Giovanni Nardini

University of Pisa

SimuLTE

• What

• How

• Where

• Why

2

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

WHAT is

SimuLTE ?

eNB

UE

• Simulator of LTE networks

• resource Allocation/Management

• Based on

• Over 40K lines of code

• Designed to be easily extended

• Open Source (LGPL)

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

3

Related Work

• Physical Layer simulators

• Ikuno et al.

– Based on Matlab

• LTE-Sim

– Standalone (C++)

• NS-3

– A lot of LTE features

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

4

• Highly modular

• Support for Simulation Automation

• Data collection/analysis

• Large set of ready-to-use models

5

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Simulation Framework

Simulation Framework

.ned

Description

.ned.ini

Parameters

.cpp

Behavior

6

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

HOW is SimuLTE made?

PDCP

RLC

MAC

PHY

LTE NIC

PDCP

RLC

MAC

PHY

SimuLTE

7

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Layer to Modules

Da

ta P

ath

getValue(…)

setValue(…)

getValue(…)

setValue(…)

Cro

ss Laye

r

8

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

atomic

atomic

Modules InheritanceeNB UE

Modules and/or C++ Classes

9

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

WHERE is SimuLTE

UEeNB

10

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Messages between Nodes

UE1

UE2

11

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Available Data

Channel Models

Pathloss

Fading

Interference

…

12

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Nodes and Networks

13

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Workflow

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

14

repeat = 2

pktSize = { 10 , 100 } bytes

interval = { 10 , 20 } ms

x2

Optimization techniques

Input 1

Input n

optimizer

Output 1

Output n

System

Statusoptimizer

15

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

IBM

• Academic license

• Input: LP files

– Text files describing the opt. problem

– Easy to build

• Output: xml files

– Well known format

– Easy to parse

CPLEX

16

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Validation/Verification

1) Base scenario evaluation

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

17

distance

Simulation

Vs

Theoretical

Validation/Verification

2) Event Traces

3) Degeneracy Test

– Extreme cases

4) Anti-bugging techniques

– ASSERTS

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

18

Validation/Verification

5) Structured testing via

– hash

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

19

– dummy modules

?

Work In Progress

• Extending Validation

• Detailed Comparison between simulators

• Improving usage of solvers

• Adding new LTE / LTE-Advanced features

– D2D / CoMP / C-RAN

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

20

Conclusions

• What:

• Simulator for LTE networks

• Resource allocation/management

• How:

• Modular

• Where:

• System/Node level

• Why

• Designed to be easy to extend

• Validation/Verification

21

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

• PAPERS

– "A comprehensive simulation analysis of LTE Discontinuous Reception (DRX)“ , G. Stea, A. Virdis, COMNET 2014

– “Effective dynamic coordinated scheduling in LTE-Advanced networks”, G. Nardini, G. Stea, A. Virdis, D. Sabella, M. Caretti, EUCNC 2014

– “Improving network performance via optimization-based centralizedcoordination of LTE-A cells”, G. Nardini, G. Stea, A. Virdis, M. Caretti, D. Sabella, CLEEN 2014

• Other Projects

– VANETS

– Robotic Swarm

• Link simulte.com or github

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

22

Conclusions• PAPERS

– "A comprehensive simulation analysis of LTE Discontinuous Reception (DRX)“ , G. Stea, A. Virdis, COMNET 2014

– “Effective dynamic coordinated scheduling in LTE-Advanced networks”, G. Nardini, G. Stea, A. Virdis, D. Sabella, M. Caretti, EUCNC 2014

– “Improving network performance via optimization-based centralizedcoordination of LTE-A cells”, G. Nardini, G. Stea, A. Virdis, M. Caretti, D. Sabella, CLEEN 2014

• Other Projects

– VANETS

– Robotic Swarm

• Link simulte.com or github

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

23

Tx/Rx modeling

UEeNB

frequency

1 ms

OFDM

K bit

RB

CQI

24

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Implementation: Channel model

CQI

MSG

25

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Scheduling

N bit

Available Data

UE ReportsSchedule List

M bit

26

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Scheduling Hierarchy

• Scheduler Type and

• Scheduling Policy

27

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Scheduling

• Two stages scheduling

– Prepare schedule

– Commit schedule

28

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Allocation Flexibility

29

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

US

ER

FR

IEN

DLY

FLE

XIB

ILITY

Example: multiband scheduling

M Resources

UE1

UEn

Schedule ?

N

30

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

multiband scheduling

31

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++

Analysis of multiband scheduling

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

10 25 50 75

RB

s

Number of UEs per cell

Avg Allocated RBs per cell

HeuristicOptimum

32

Antonio Virdis - SimuLTE - A modular

System-Level Simulator For LTE/Lte-A

Networks based on Omnet++