Lte x2 handover in eventtriggered handover procedures, each ue evaluates the event condition every time a new. The first document is an overview of lte handover, providing basic information about the procedure. The s1 handover procedure is performed between two enbs without the x2 interface. Lte uses universal frequency reuse n1 without soft handoff. Lte ue event measurement reportingevent a1,a2,a3,a4,a5,b1,b2. Therefore, the ltesae should be more secure than the 3g network and especially should have a strengthened defense against the current attacks from the. This paper discusses the lte handover procedures that are standardized in 3gpp release 8 and describes a new lte handover. Handover between lte and 3g radio access technologies. Fast authentication during handover in 4g ltesae networks. While the lte handover procedures defined in release 8 provide mobility support, they may not be suitable for all scenarios and could result in unsatisfactory user experience even when compared to legacy 2g and 3g systems.
There are many specific reasons why lte dropped altogether soft handover connectbeforebreak from the system design. Few last articles were about handover in lte network. Intralte handover intrammesgw as mentioned in the previous section, based on the measurement report from the ue, the senb decides to handover the ue to another enodeb tenb. The source enodeb initiates a handover by sending handover required message over the s1mme reference point. Consequently, we assume the same x2based handover ho procedure as for lte standard 7. Today we will be talking about handovers from eutran to utran, from 4g to 3g. Lte evolved from an earlier 3gpp system known as the universal mobile telecommunication system umts, which in turn evolved from the global system for mobile communications gsm. The simplest multi cell cases would be between two lte cells. From old enb to new enb, with or without using new mmesgw, with or without using x2 interface, and so on. When the ue detects radio link problems, it starts the rlf timer, a. Simulation of a realistic lte wireless network requires.
Pdf a novel cellselection optimization handover for. Lte x2 handover sequence diagrams lte long term evolution. The autotuning is carried out by adapting handover parameters of each base station. Now lets jump into detailed technical aspects of lte handover. Interdomain handover technologies in lte for voice volte. Free 4g lte books download ebooks online textbooks.
Ueassisted measurements are made and reported by the ue to the network. It means this is mainly for ue side aspect of handover process. Ue is handed over using an s1 handover if the x2 interface is not available between the source and target enodebs. Jul 04, 2014 user description, gsmumts lte cell reselection and handover 4. The thesis work is about the investigation of different handovers in the 3g umts network which is the vital issue to the network to maintain the users connection during in the ongoing. When it receives this signal, the enodeb sends a handover from lte command for the terminal to switch radio systems. Lte s1 handover s1 handover lte mobile enodeb network. This procedure may relocate the mme andor the serving gw. Late path switch only once the handover is successful, the packet core is involved. Handover in lte free download as powerpoint presentation. Jun 03, 2017 lte enodebs can directly communicate with other enodebs on the x2 interface. The enodeb sends measurement control messages to the ue giving reporting thresholds. These latencies meet the expected requirements concerning control plane delay budgets for 5g networks. It can be downloaded here and the offer includes a resource guide on lte and a poster, being this last one mailed for free to any address you provide.
The resource guide includes all the specs and information of lte networks and testing equipment and can work very. The x2 handover is used when direct connectivity between source and target enbs exists. Softer handover softer handover is a special case of soft handover where the radio links that are added and removed belong to the same node b. When lte system was developed one of the big technical feature from umts softsofter handover was missing from the architecture. This paper investigates autotuning of lte mobility algorithm. Measurement based reporting used in lte to trigger handover. Requirements for evolved utra eutra and evolved utran eutran. A very interesting introduction to lte networks and specially to lte testing. Test measurement challenges and field environment test planning school of electrical engineering master. The tenb checks for resource availability and, if available, reserves the resources and sends back the handover request acknowledge message. Selftuning and selfoptimisation algorithms are currently studied with the aim of enriching the lte standard. In softer handover, the nodeb can receive the signal in macro diversity with maximum ratio combining.
Nov 06, 2016 in fact, when a handover is beginning, an lte ue has to go into a compressed mode where it listens to its current cell for part of the time and searches for a new cell the rest of the time. Hard handover mechanism is adopted to be used in lte advanced. Lte s1 handover s1 handover lte mobile enodeb network core. When a ue is camped on the lte network, it would need to fallback to the legacy 2g3g networks when coverage or capacity dictates. In this context, one of the main goals of lte is to provide fast and seamless handover from one cell to another to meet a strict. Lte stands for long term evolution and it was started as a project in 2004 by telecommunication body known as the third generation partnership project 3gpp. Note that when the enodeb receives the handover command from the mme, it begins forwarding data packets received from the sgw. Ims is the 3gpp voice over ip solution which is being deployed in the lte networks as the voice solution. Aug 31, 2012 coordinated multipoint comp transmission and reception is the key technique in lte advanced to improve the celledge throughput andor system throughput. Load information resource status update x2 interface model nicola baldo the lena ns3 module 22. The x2 interface is used to perform a handover between enodeb. Intra eutran handover is used to hand over a ue from a source enodeb to a target enodeb using x2 when the mme is unchanged. Handover principles and handover measurements in lte. In soft handover macro diversity with selection combining is.
Coordinated multipoint comp transmission and reception is the key technique in lteadvanced to improve the celledge throughput andor system throughput. Consequently, high levels of interference and low sinr can be expected near the cell edge. By default, user equipment in the lte network detect suitable neighbor cells without the. Just as ethernet and the internet have different types of qos, for example, various levels of qos can be applied to lte traffic for different applications.
Frequency division duplexing fdd and time division duplexing tdd both paired and unpaired. In this context, one of the main goals of lte is to provide fast and seamless handover from one. Mar 30, 2012 few last articles were about handover in lte network. A handover report contains the summation of all the work functions and responsibilities that an individual was able to execute within a particular time period. Hard handover mechanism is adopted to be used in lteadvanced. Handover process in lte, lte handover tutorial teletopix. This procedure is used to handover a ue from a source enodeb senb to a target enodeb. The messaging in x2 handover is detailed in lte x2. In fact, when a handover is beginning, an lte ue has to go into a compressed mode where it listens to its current cell for part of the time and searches for a new cell the rest of the time. Enhanced handover mechanism in long term evolution lte networks.
Lte s1 handover s1 handover lte mobile enodeb network core network ue target enodeb source enodeb mme sgw pgw eventstudio system designer 6 17feb14 21. Selfoptimization of handover parameters in lte networks. The handover procedure for intralte handover using the s1 interface is very similar to that of intralte handover using the x2 interface, except the involvement of the mme in relaying the handover signaling between the senb and tenb there are two main differences here. Intrafrequency handover means mobility in connected mode between two different cells, but within same lte frequency, this topic will be assigned for event a3 which is used for lte intrafrequency handover. The data path switching goes through several steps to accomplish a seamless handover. Full 3g fundamentals 3g architecture training course. The handover without tau procedure is described through three companion documents. Intralte handover using the s1 interface 3glteinfo. Audience this tutorial has been designed for audiences with a need to understand the lte technology basics in very simple terms. The s1based handover procedure is used when the x2based handover cannot be used. Just like an after action report, you can provide details of what has already been accomplished during your shift within the handover report samples. Selfoptimization of handover parameters in lte networks veronique capdevielle, afef feki alcatellucent belllabs, france email. Before discussing about why lte skipped soft handover and only implemented hard handover, lets check the basic concept of. Lte tdd which is also referred to as tdlte provides the long term evolution path for tdscdma based networks.
Sorry guys, today i dont have time to create abstract picture which we could use to start from. This document describes the handover procedure defined as emm. Index termshandover, 5g, sdn, nfv, virtualized lte. In the future, voice and tv phone services will also be provided in lte by way of handset terminals. Optimized performance evaluation of lte hard handover algorithm. Enhanced seamless handover algorithm for wimax and lte roaming article pdf available in advances in electrical and computer engineering 4.
S1 interface based handover lte and beyond techblog. This event type can also be used for interfrequency handover and it is configurable in enodeb side to choose the event type for interfrequency. The second and third documents explain the procedures for x2 handover and s1 handover in an intralte environment, respectively. In the scenario described here serving gw is also unchanged. A novel cellselection optimization handover for long term evolution lte macrocell using fuzzy topsis.
A3based measurements and handover model for ns3 lte. The ue receives the rrcconnectionreconfiguration message with necessary parameters i. Long term evolution lte is a standard for radio technology developed by the 3rd generation partnership project 3gpp. Apr 10, 2010 the handover request acknowledge message includes a transparent container to be sent to the ue as an rrc message to perform the handover. The long term evolution lte of the 3gpp 3rd generation partnership project radio access network is in early stage of specification. In this approach, all the ho procedures at the ac are unnoticed by the rc network i.
Pdf enhanced seamless handover algorithm for wimax and. In this case source and target cells are part of the same lte network. Introducing lte advanced pdf 36p 4g wireless systems lte technology pdf slides 82p the evolution to 4g cellular systems lte advanced pdf 28p lte the future of mobile broadband technology pdf 19p summary introduction to wireless lte 4g architecture and key business implications pdf 78p antenna design considerations for lte mobile. Pdf enhanced seamless handover algorithm for wimax and lte. Analyzing x2 handover in lteltea konstantinos alexandris, navid nikaein, raymond knopp, and christian bonnet eurecom, biot, france email. Enhancing lte celledge performance via pdcch icic fujitsu. Sep 05, 2014 please read the lte documentation carefully. Lte qos lte architecture supports hard qos, with endtoend quality of service and guaranteed bit rate gbr for radio bearers. Intralte intramme sgw handover using the x2 interface. Dec 06, 20 the handover procedure for intra lte handover using the s1 interface is very similar to that of intra lte handover using the x2 interface, except the involvement of the mme in relaying the handover signaling between the senb and tenb. Handover request handover request ack handover preparation failure sn status stransfer ue context release son primitives. The senb issues a handover request message to the tenb.
Mar 03, 2011 i have case handover 4g to 3g successful,after handover finish speed download 3g very slow handover buy load balancing test only 4g. S1 interface based handover lte and beyond techblog on. We call this kind case as intrarat multi cell scenario. Handover implementation in a 5g sdnbased mobile network. Jun 03, 2017 the data path switching goes through several steps to accomplish a seamless handover. Lte mobility enhancements 1220079 page 4 the target cell for handover, but not good enough for the ue to be able to decode the handover command from the source enb1. User description, gsmumtslte cell reselection and handover 4. Lte long term evolution is a fourth generation cellular network technology that provides improved performance related to data rate, coverage and capacity compared to legacy cellular systems. Lte x2 handover between enodebs served by the same mme. Before discussing about why lte skipped soft handover and only implemented hard handover, lets check the basic concept of softsofter handover. May 23, 2014 when lte system was developed one of the big technical feature from umts softsofter handover was missing from the architecture. Joint processing jp in comp technology provides multiple data transmission points for each user among multiple cooperated radio base stations. More complicated probably the most complicated cases are the multi cell scenario among different technologies different rats. Handover procedure there are two types of handover procedure in lte for ues in active mode.
In soft handover macro diversity with selection combining is selected. The research topic of this thesis which is lte handover performance evaluation. In particular, x2 handover is introduced to allow neighboring. The s1handover procedure is performed between two enbs without the x2 interface. Lte long term evolution long term evolution signaling flows and tutorials for lte. Handover in particular is more complicated in lte as lte has to deal with intralte handovers as well as handovers between lte and utran. The handover procedure in this section is very similar to that in the previous section intralte handover using the x2 interface, except the. Handover in lte lte telecommunication transmission.
Following is the overall and simplest form of lte lte handover procedure. A small cell is one of key factors in a long term evolution lte and lteadvanced ltea system. Lte qos lte architecture supports hard qos, with end to end quality of service and guaranteed bit rate gbr for radio bearers. Umts long term evolution lte technology introduction. This document will provide the basic concept of lte handover and the.
Physicalcommunication32010217244 219 table 1 lte,lteadvanced,andimtadvancedperformancetargetsfordownlinkdlanduplinkul. While the lte handover procedures defined in release 8 provide mobility support, they. Apr, 2010 by lteworld in blog, handover, intra, intra eutran handover, sgw, eutran, enb, lte, mme. No need for the path switch procedure between the tenb and mme, as mme is aware of the handover. Following is the overall and simplest form of ltelte handover procedure. This article describes technologies for enabling smooth voice and tv phone interd\ omain handover especially during the radio access network migration phase when lte and 3g networks coexist and where both lte and 3g radiosnetwork domains will. Lte includes an fdd frequency division duplex mode of operation and a tdd time division duplex mode of operation. Because the lte mac is fully scheduled, qos is a natural fit. Speed normal handover ps 4g to 3g, speed on 3g very slow for iphone, hawei, nokia, this samsung test speed normal. Lte enodebs can directly communicate with other enodebs on the x2 interface.
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