Handover mechanisms in 3GPP long term evolution (LTE)

Lin, C

Permalink

Publication Type:: Thesis
Issue Date:: 2013

Open Access

Recently Added
In Progress
Open Access

This item is open access.

Adobe PDF

Download contents and abstractAdobe PDF (259.97 kB)

Adobe PDF

Download thesisAdobe PDF (13.2 MB)

View statistics

Full metadata record

Field	Value	Language
dc.contributor.author	Lin, C
dc.date.accessioned	2014-05-27T01:28:39Z
dc.date.available	2014-05-27T01:28:39Z
dc.date.issued	2013
dc.identifier.uri	http://hdl.handle.net/10453/28011
dc.description	University of Technology, Sydney. Faculty of Engineering and Information Technology.	en_US
dc.description.abstract	The Long-Term Evolution (LTE) network is a new radio access technology (RAT) proposed by the Third Generation Partnership Project (3GPP) to provide a smooth migration towards the fourth generation (4G) network. Long Term Evolution-Advanced (LTE-A) is a major enhancement of the LTE standard proposed by the 3GPP to meet the 4G mobile communication standards. Handover is one of the key components in cellular network mobility management. Handover is a mechanism that transfers an on-going call or data session from one base station (BS) to another BS or one sector to another sector within the same BS. Hard handover has been adopted in LTE and LTE-A systems by 3GPP due to the flat IP-based architecture and the lack of a centralized controller. The use of hard handovers reduces the complexity of the handover mechanism and minimizes the handover delay. However, the hard handover approach causes call drops that may result in lost data during a session. The objective of this thesis is to provide the basis for improving handover performance in the LTE and LTE-A systems. A C++ system level simulator that can dynamically model the large and complex downlink LTE and LTE-A was developed as part of this research work followed by a proposed handover parameters optimization method. The simulation results show that the handover parameters optimization method can effectively minimize the unnecessary number of handovers while maximizing the system throughput. Under an initial assumption of an ideal mobile cellular channel (i.e. the mobile cellular channel is not subject to any impairment), this thesis proposes a new handover algorithm in the LTE system and three new Coordinated Multiple Transmission and Reception (CoMP) handover algorithms in the LTE-A system. The simulation results show that the proposed handover algorithm outperforms well-known handover algorithms in the LTE system by having less number of handovers, shorten total system delay whilst maintaining a higher total system throughput. The performance of the proposed CoMP handover algorithms are evaluated and compared with open literature CoMP handover algorithm via simulation. It is shown via simulation that the proposed CoMP handover algorithms can improve the system throughput and minimize the system delay in a saturated system scenario in the LTE-A system. A more practical LTE-A system where the mobile cellular channels are subject to impairments is considered for performance testing of selected CoMP handover algorithms. The impairments for a practical LTE-A system are assumed to be in two scenarios: outdated feedback and missing feedback. It is shown via computer simulations that the system throughput and system delay are very sensitive against outdated Channel Quality Information (CQI) feedback and missing CQI feedback. Furthermore, a handover failure caused by an inappropriate feedback increases the number of unnecessary handovers which require additional resources in the network and may significantly degrade the system performance.	en_US
dc.format	Thesis (PhD)	en_US
dc.language.iso	en	en_US
dc.relation	https://opus.lib.uts.edu.au/bitstream/10453/28011/2/02Whole.pdf
dc.rights	info:eu-repo/semantics/openAccess
dc.rights	The author owns the copyright in this thesis including all reproduction and reuse rights for the work. The work may not be altered without the permission of the copyright owner. Attribution is essential when quoting or paraphrasing from this thesis.
dc.rights	au.edu.uts.lib/ppc
dc.subject	3GPP.	en
dc.subject	LTE.	en
dc.subject	Long-Term Evolution.	en
dc.subject	Telecommunications.	en
dc.subject	LTE-Advanced.	en
dc.subject	Handover algorithm.	en
dc.title	Handover mechanisms in 3GPP long term evolution (LTE)	en_US
dc.type	Thesis
utslib.copyright.status	open_access

Abstract:

The Long-Term Evolution (LTE) network is a new radio access technology (RAT) proposed by the Third Generation Partnership Project (3GPP) to provide a smooth migration towards the fourth generation (4G) network. Long Term Evolution-Advanced (LTE-A) is a major enhancement of the LTE standard proposed by the 3GPP to meet the 4G mobile communication standards. Handover is one of the key components in cellular network mobility management. Handover is a mechanism that transfers an on-going call or data session from one base station (BS) to another BS or one sector to another sector within the same BS. Hard handover has been adopted in LTE and LTE-A systems by 3GPP due to the flat IP-based architecture and the lack of a centralized controller. The use of hard handovers reduces the complexity of the handover mechanism and minimizes the handover delay. However, the hard handover approach causes call drops that may result in lost data during a session. The objective of this thesis is to provide the basis for improving handover performance in the LTE and LTE-A systems. A C++ system level simulator that can dynamically model the large and complex downlink LTE and LTE-A was developed as part of this research work followed by a proposed handover parameters optimization method. The simulation results show that the handover parameters optimization method can effectively minimize the unnecessary number of handovers while maximizing the system throughput. Under an initial assumption of an ideal mobile cellular channel (i.e. the mobile cellular channel is not subject to any impairment), this thesis proposes a new handover algorithm in the LTE system and three new Coordinated Multiple Transmission and Reception (CoMP) handover algorithms in the LTE-A system. The simulation results show that the proposed handover algorithm outperforms well-known handover algorithms in the LTE system by having less number of handovers, shorten total system delay whilst maintaining a higher total system throughput. The performance of the proposed CoMP handover algorithms are evaluated and compared with open literature CoMP handover algorithm via simulation. It is shown via simulation that the proposed CoMP handover algorithms can improve the system throughput and minimize the system delay in a saturated system scenario in the LTE-A system. A more practical LTE-A system where the mobile cellular channels are subject to impairments is considered for performance testing of selected CoMP handover algorithms. The impairments for a practical LTE-A system are assumed to be in two scenarios: outdated feedback and missing feedback. It is shown via computer simulations that the system throughput and system delay are very sensitive against outdated Channel Quality Information (CQI) feedback and missing CQI feedback. Furthermore, a handover failure caused by an inappropriate feedback increases the number of unnecessary handovers which require additional resources in the network and may significantly degrade the system performance.

Please use this identifier to cite or link to this item:

http://hdl.handle.net/10453/28011