Modelling Interfernce for Wireless LTE networks in OPNET

Studienarbeit Kick off Presentation

Vivek Tyagi (21152475)vivek.tyagi@tu-harburg.de

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Agenda

• Background and Impulse towards topic• Project Description• Milestones planning• Progress So far• Further Enhancements (TBD)• Discussion

Institute of Communication NetworkComNets@tuhh.de

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Background and Impulse towards topic

Any wireless signal is usually affected from• Attenuation over distance• Doppler shift• Multipath fading• Interference (Missing)

All are required for analysis and optimization of the performance of wireless networks

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Background and Impulse towards topic

• LTE advanced – Frequency reuse factor 1• All frequency resources used in all eNBs• Leads to high amount of Interference• Interference based coordination /scheduling

required.

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Arbeit Description

• Modeling of interference in ComNets LTE model for performance analysis of simple scenario.

• Scenario:- – Two eNBs– One UE per Base station– Square topology– Both Base stations uses same band (100%)

• Without user mobility• With user mobility

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Arbeit Description

• Modules affected– Mobility Model : For Topology and movement

design• SINR calculation

• RPL(others) is missing

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Arbeit Description

– MAC Scheduler : For performance analysis of various current scheduling algorithms• Blind Equal Throughput• Maximum Throughput• Proportional Fair• Optimized Service Aware

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Arbeit Description

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Progress So Far

• Understanding of OPNET simulator• Understanding of Mobility Model• Understanding of MAC scheduler• Proposal for changes in Mobility Model– For topology– For mobility

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Milestones TBD

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• 15th March : Code implementation of 2 eNB scenario• 30th March : Code validation and Test RunsMarch• 15th April : Collection of Results • 20th April : First Interim Report Discussion• 30th April : Calibration/Enhancement of Model• 15th-30th April : Parallel Report Writing April• 7th May : Comparison of results to a standard model(3GPP)• 15th May : Detailed Analysis and additional Enhancements• 22th May : Further Result collection (if required)• 30th May: Final Presentation of project and Report Submission• May : Parallel report writing

May

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Further Discussions

• Interference coordinated MAC scheduling• Multi UE scenarios• Multi Base Station scenarios– With User mobility– Without User mobility

Open ended discussion

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A Distributed Interference-aware Load balancing Algorithm for LTE Multi-Cell Networks

• Problem formulation– Concave utility function, s.t. constrains– Convex program with a concave objective function

• Lagrangian relaxation (duality)– Decompose into subproblems by relaxing the constrains (load

distribution, BS assignment, bandwidth allocation)

• Solution for Lagrangian relaxation– Solving the subproblems– Optimal solution– Ascent methods (several steps), cover the integer constrains

• Cellular network aspects (each step)– Distributed algorithm for the optimal LB, considering e.g. HO user pair,

HO criterion, candidate user sets…

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Utility-Based Resource Allocation for Mixed Traffic in Wireless Networks

• Utility function– QoS users: Sigmoid function (convex, concave)– BE users: Concave function

• Solution– Lagrangian method with Karush-Kuhn-Tucker condition (KKT)– Sufficient conditions for optimal allocation derived

• Algorithms– I. QoS users only– II. BE users only

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14Institute of Communication Network

ComNets@tuhh.de

THANK YOU….