CBL - Campus del Baix Llobregat

Projecte llegit

Títol: Análisis de los patrones de asociación óptimos para los usuarios de las redes 802.11

Estudiants que han llegit aquest projecte:

Director/a: ZOLA, ENRICA VALERIA

Departament: ENTEL

Títol: Análisis de los patrones de asociación óptimos para los usuarios de las redes 802.11

Data inici oferta: 30-01-2017     Data finalització oferta: 30-09-2017


Estudis d'assignació del projecte:
    GR ENG TELEMÀTICA
Tipus: Individual
 
Lloc de realització: EETAC
 
Paraules clau:
simulation, multi-objective optimization, 802.11, mobility, handover
 
Descripció del contingut i pla d'activitats:
The deployment of a large number of Access Points (APs) in public areas presents a new
paradigm in which more than one AP may serve a given station at a time. Recently, a
network model has been proposed to derive the optimal association strategy for IEEE
802.11 stations by solving a multi-objective optimization function that maximizes the
download rates and minimizes the number of handovers. As a handover implies an
extra cost due to necessary signaling to be exchanged, the system throughput may
slightly decrease while the number of handovers reduces. The aim of this project is to
fully analyze the impact of the handover cost on the system throughput and on the
association scheme.
 
Overview (resum en anglès):

In recent years, an increment of devices requesting an Internet connection has been seen. Due to this demand, the number of access points (APs) has increased. This increase causes situations in which a device is within reach of more than one AP to which it can connect.

Because systems find to balance the load, they can force a change of access point that can cause a "ping-pong" effect (i.e., bouncing continuously between one AP and the other) even in static stations. The user who has open applications may perceive these frequent changes that cause disconnections and a greater battery wear.

In order to reduce these types of problems, an optimization model with multi-objective function has been presented in 2014 that reduces the handovers and maximizes the data download [1].

In this work it can find the characteristics of the multi-objective function, the instructions that were taken to perform all the tests and the results obtained from the various simulations. The study focuses on performing the simulations with the different values of the parameters to be taken into account when making an AP handover in a WLAN.

In each scenario, a comparison has been made of the handovers that occur through the different scenarios. To obtain the results, the scenarios were first generated using the Matlab tool and then the simulations were performed using the CPLEX optimization tool.

By means of the obtained results it can be determined that, using the multi-objective function, it is possible to reduce the ping-pong effect, considerably reducing the HO number without affecting the bitrate offered by the system.

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