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Optimization of algorithms for mobility in cellular systems

Christensen, Bernt LU and Knape, Olof LU (2016) EITM01 20161
Department of Electrical and Information Technology
Abstract
Inter-frequency measurements are needed to determine when user equipment should make a handover to the best available base station in a cellular mobile network. The measurements are expensive from a resource point of view and therefore there is a need for optimization of this kind of measurements. In this work both this optimization and a way to predict the future of the measurements have been evaluated in a simulated Long-Term Evolution network. Both fast and slowly moving user equipment have been tested and the prediction was made by storing old measurements and calculating the gradient of the signal power. Depending on the resulting signal's gradient, different decisions on what to do were made. The results were then compared to the... (More)
Inter-frequency measurements are needed to determine when user equipment should make a handover to the best available base station in a cellular mobile network. The measurements are expensive from a resource point of view and therefore there is a need for optimization of this kind of measurements. In this work both this optimization and a way to predict the future of the measurements have been evaluated in a simulated Long-Term Evolution network. Both fast and slowly moving user equipment have been tested and the prediction was made by storing old measurements and calculating the gradient of the signal power. Depending on the resulting signal's gradient, different decisions on what to do were made. The results were then compared to the traditional way of controlling the inter-frequency measurements, in terms of throughput, handover failures and other quality factors.

The results from the simulations show that there is some optimization that can be made without compromising the connection. More specifically, the time spent measuring inter-frequency has been successfully improved (lowered). Handover failures have been harder to control and the throughput has more or less been unchanged throughout the simulations. The speed of the user equipment influenced the results a lot and no setup was found that works best with all UE speeds. (Less)
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author
Christensen, Bernt LU and Knape, Olof LU
supervisor
organization
course
EITM01 20161
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Handover, Long-Term Evolution, UE speed, measurement optimization, inter-frequency measurement, prediction, simulation
report number
LU/LTH-EIT 2016-509
language
English
id
8878244
date added to LUP
2016-06-08 14:20:11
date last changed
2016-06-09 14:58:18
@misc{8878244,
  abstract     = {Inter-frequency measurements are needed to determine when user equipment should make a handover to the best available base station in a cellular mobile network. The measurements are expensive from a resource point of view and therefore there is a need for optimization of this kind of measurements. In this work both this optimization and a way to predict the future of the measurements have been evaluated in a simulated Long-Term Evolution network. Both fast and slowly moving user equipment have been tested and the prediction was made by storing old measurements and calculating the gradient of the signal power. Depending on the resulting signal's gradient, different decisions on what to do were made. The results were then compared to the traditional way of controlling the inter-frequency measurements, in terms of throughput, handover failures and other quality factors. 

The results from the simulations show that there is some optimization that can be made without compromising the connection. More specifically, the time spent measuring inter-frequency has been successfully improved (lowered). Handover failures have been harder to control and the throughput has more or less been unchanged throughout the simulations. The speed of the user equipment influenced the results a lot and no setup was found that works best with all UE speeds.},
  author       = {Christensen, Bernt and Knape, Olof},
  keyword      = {Handover,Long-Term Evolution,UE speed,measurement optimization,inter-frequency measurement,prediction,simulation},
  language     = {eng},
  note         = {Student Paper},
  title        = {Optimization of algorithms for mobility in cellular systems},
  year         = {2016},
}