P ERFORMANCE E VALUATION OF B ASE S TATION A PPLICATION O PTIMIZER Nana Ginzbourg Instructor: Dr. Ronit Nossenson Internal Instructor: Dr. Tami Tamir

O VERVIEW Introduction LTE Network NS 2 Simulator Base Station Application Optimizer Implementation Model – network topology Traffic generation and cache implementation Simulation Trace analyzers Results Conclusions and Future work

I NTRODUCTION Cellular operator take advantage of new technologies and offer rich services to advanced handset Backhaul lines are still limited to 2 Mbps capacity Leads to backhaul bottleneck problem

P OSSIBLE S OLUTIONS Backhaul lines upgrade Application solution Data reduction No need in upgrade Integrated solutions Base Station Application Optimizer Analyze and optimize user data in application level Prevent unnecessary data travelling through backhaul network Less painful upgrade

P ROJECT G OALS Implement Base Station Application Optimizer over an LTE network in NS-2 simulator Evaluate solution performance in various simulations: Realistic mixture of applications Different cache hit rates Changing network load – number of users Different queue sizes

LTE N ETWORK

B ASE S TATION A PPLICATION O PTIMIZER

NS 2 S IMULATOR Open Source event driven simulator History: 1989 – REAL network simulator 1995 – VINT Project with DARPA Support a big variety of protocols and keeps growing Simulator Implementation: Backend in C++ - compiled hierarchy Frontend in Otcl – interpreter with similar hierarchy Simulation scripts -.tcl

NS 2 S IMULATOR

B ASE S TATION A PPLICATION O PTIMIZER I MPLEMENTATION Open source: optimizer/ optimizer/ Four stages: Network Topology definition Traffic generation Configurations and simulations over different parameters Trace analysis

N ETWORK T OPOLOGY D EFINITION Wired Nodes eNode-B Serving Gateway PDN-GW Server Wireless Nodes User equipment DropTail queuing algorithm Oversubscription factor at S1 interface is 1/3

T RAFFIC G ENERATION APPLICATIONS D ISTRIBUTION

T RAFFIC G ENERATION IN NS 2 ParametersRate (kbps) ProtocolPacket Size (bytes) Generator 64UDP200CBRVoIP ON – 200ms OFF – 2000ms Shape – TCP1040Pareto Web ON – 2000ms OFF – 2000ms Shape – TCP1300ParetoVideo ON – 2000ms OFF – 200ms Shape – TCP1500ParetoFile

T RAFFIC G ENERATION C ACHE I MPLEMENTATION

C ONFIGURATION AND S IMULATIONS All simulation parameters are configurable Command line Configuration.tcl Run simulations using main.tcl and override relevant parameters Number of end users Buffer size Hit rates per application Users distribution per application

T RACES A NALYSIS

T OTAL B ANDWIDTH A NALYZER Output: total number of bytes per application type over S1 interface Implementation: Combination of shell and awk scripts Summarize packets sizes over S1 interface using source and destination id Use flow id to separate results per application type and hit rate scenarios

B ANDWIDTH PER SECOND A NALYZER Output: Total number of bytes per second per application type over the S1 interface Implementation: Awk script Use an array[simulation_length_seconds] Summarize packet sizes according to source and destination nodes, flow id and packet size.

E ND -T O -E ND DELAY AND D ROPPED STATISTICS ANALYZER Output: End-to-end delay Dropped packets percentage Implementation: Array per application type Packet id indicates the index in the array Send event -> save start time Receive event -> save end time Dropped event -> update with -1

R ESULTS Primary Simulation 20, 50 and 100 users User Equipment links buffer size – 10 packets Cache Hit rate impact of results Standard hit rates: 20% web, 40% video and files Increase and decrease hit rate by 10% Buffer Size impact on results Increase and decrease buffer size in 25% Keep medium hit rate

T OTAL TRANSFERRED KB WITH 20, 50 & 100 CONCURRENT USERS

D ATA R EDUCTION P ER A PPLICATION T YPE

D ATA R EDUCTION O VER T IME

D ATA R EDUCTION F ACTOR Reduction Factor Traditional KB OPTIMIZED KB Application Users Web Video File Sharing VoIP Total Web Video File Sharing VoIP Total Web Video File Sharing VoIP Total

D ROPPED S TATISTICS Optimized KB Traditional KB Application Users % Dropped# Drop% Dropped# Drops 0.00%0 0 Web %0 0 Video 0.00%0 0 File Sharing 0.00%00.05%19 VoIP 0.00%0 19 Total 0.07% %114 Web % %291 Video 0.03% %249 File Sharing 0.06%620.06%65 VoIP 0.03% %719 Total 0.05% %5954 Web % %12333 Video 0.05% %9528 File Sharing 0.10% %12503 VoIP 0.04% %40318 Total

A VERAGE D ELAY Reduction % Traditional KB OPTIMIZED KB Application Users 15.56% Web % Video 48.93% File Sharing 0.06% VoIP 20.45% Web % Video 39.39% File Sharing 0.23% VoIP 26.16% Web % Video 39.87% File Sharing 0.86% VoIP

I MPACT OF C ACHE HIT RATE ON D ATA R EDUCTION F ACTOR High Hit Rate Medium Hit Rate Low Hit Rate Application Users Web Video File Sharing 1.00 VoIP Total Web Video File Sharing 1.00 VoIP Total Web Video File Sharing 0.98 VoIP Total

I MPACT OF C ACHE HIT RATE ON D ROP P ACKETS P ERCENTAGE % Drop High Hit Rate % Drop Low Hit Rate %Drop Traditional Application 0.15%0.26%1.96% Web 0.05%0.12%1.57% Video 0.12%0.20%1.50% File Sharing 0.23%0.46%4.96% VoIP 0.09%0.17%2.04% Total

I MPACT OF C ACHE HIT RATE ON A VERAGE D ELAY % Reduction High Hit Rate % Reduction Medium Hit Rate % Reduction Low Hit Rate Application 25.24%26.16%19.89% Web 73.32%69.26%67.37% Video 46.57%39.87%36.55% File Sharing 0.98%0.86%0.40% VoIP

I MPACT OF BUFFER S IZE ON DATA REDUCTION FACTOR Large Buffer Size Medium Buffer Size Small Buffer Size Application Users Web Video File Sharing 1.00 VoIP Total Web Video File Sharing 1.00 VoIP Total Web Video File Sharing 0.98 VoIP Total

I MPACT OF BUFFER SIZE ON DROPPED PACKETS PERCENTAGE % Drop Optimized Large Buffer % Drop Traditional Large Buffer % Drop Optimized Small buffer %Drop Traditional Small buffer Application 0.05%0.11%0.09%2.17% Web 0.05%0.16%0.05%1.70% Video 0.09%0.24%0.12%1.75% File Sharing 0.16%0.17%0.21%4.09% VoIP 0.07%0.18%0.08%2.10% Total

I MPACT OF BUFFER SIZE ON A VERAGE PACKETS DELAY % Reduction Large Buffer Size % Reduction Medium Buffer Size % Reduction Small Buffer Size Application 25.20%26.16%25.31% Web 73.30%69.26%73.48% Video 46.55%39.87%46.57% File Sharing 1.00%0.86%1.08% VoIP

C ONCLUSIONS Open Source implementation of LTE model Configurable Easy to install and use Provides functionalities like different application traffic generation and users distribution Base Station Application Optimizer implementation Trace Analyzers Performance Evaluation: Total bytes transferred reduction factor: Average delay reduced by 75% Packet loss percentage reduced from 2% to 0.05%

F UTURE W ORK Add User mobility support: Implement basic handover process in NS 2 Support several deployment modes of Base Station Application Optimizer in an LTE network Implement new traffic generator in NS 2

R EFERENCES Patrick Donegan, "Backhaul Strategies for Mobile Carriers", In Heavy Reading, Vol. 4 No. 4, Ronit Nossenson, “Base Station Application Optimizer”, The International Conference on Data Communication Networking 2010 (DCNET), Athens, Greece. Holma, H., and Toskala, A., LTE for UMTS – OFDMA and SC- FDMA Based Radio Access, John Wiley & Sons Ltd, United Kingdom, Qin-long Qiu, Jian Chen, Ling-di Ping, Qi-fei Zhang, Xue-zeng Pan, 2009, LTE/SAE Model and its Implementation in NS 2, 2009 Fifth International Conference on Mobile Ad-hoc and Sensor Networks, Fujian, China, pp LTE implementation: The Network Simulator (NS2),

R EFERENCES Introduction to Network simulator NS 2" by Teerawat Issariyakul and Ekram Hossain, 2009 Springer Science+Business Media, LLC Project source code and results: optimizer/ optimizer/ Allot Mobile Trends, Global mobile broadband traffic report, H1/2011. GNU Awk,