Fourth generation wireless systems technology, lte long term evolution. The source enodeb initiates a handover by sending handover required message over the s1mme reference point. Optimizing the parameters of handover in lte using son system. Selfoptimization of handover parameters in lte networks. Mobileipp is a mobility protocol based on proxy messaging or using proxy entities to handle handover in the network, enodebs act on behalf of the mobile node sending ue context information and communicating with target enodebs to accelerate the creation of tunnels. Consequently, the limited lte coverage will result in many interradio access technology rat handovers from lte to 2g3g and vice versa. 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. Introduction the long term evolution lte of umts universal mobile telecommunications system is. X2 handover is performed between a source enb and a target enb through the x2 interface. Handover in lte lte telecommunication transmission. Lte long term evolution long term evolution signaling flows and tutorials for lte.
Handover scenario and procedure in ltebased femtoc ell. Therefore, the ltesae should be more secure than the 3g network and especially should have a strengthened defense against the current attacks from the. There are many specific reasons why lte dropped altogether soft. The handover without tau procedure is described through three companion documents. The data path switching goes through several steps to accomplish a seamless handover. An rlf occurs shortly after a successful handover from a source cell to a target cell or a handover failure occurs during the handover procedure. Handovercommand message this message is sent by the mme to inform the source enb that resources for the handover have been prepared at the target side. Selfoptimization of handover parameters in lte networks veronique capdevielle, afef feki alcatellucent belllabs, france email. 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 the ue detects radio link problems, it starts the rlf timer, a. Lte s1 handover between enodebs lte long term evolution. Enhanced handover mechanism in long term evolution lte networks. Jose eduardo charters ribeiro da cunha sanguino supervisor.
Apr, 2010 by lteworld in blog, handover, intra, intra eutran handover, sgw, eutran, enb, lte, mme. The points that will be achieved are the types of mobility, intra and inter frequency handover, the events for the handover procedure, and what measurement gap is for. Handover delay and interruption time extracted from hoto1119 figure 2. Lte x2 handover call flow procedure prashant panigrahi december 4, 20 4 intra lte intrammesgw handover using the x2 interface is used to handover a ue from a source enodeb senb to a target enodeb tenb using the x2 interface when the mobility management entity mme and serving gateway sgw are unchanged. The tenb checks for resource availability and, if available, reserves the resources and sends back the handover request acknowledge message. Keywordslteadvanced,lteadvanced,lteadvanced, handover, combinedhandover,handover,handover, handovernegotiation,carrieraggregation i. Load balancing via interfrequency handovers in lte networks goncalo ourique fernandes thesis to obtain the master of science degree in electrical and computer engineering examination committee chairperson. Introduction on the progress of researching for key technology and standard of r10 for lteadvanced system, enhanced. The first document is an overview of lte handover, providing basic information about the procedure. Lte handover restriction list configuration mode commands forbidden. Pdf enhanced handover mechanism in long term evolution. Visualether protocol analyzer wireshark based visual protocol analysis and system design reverse engineering tool. Now lets jump into detailed technical aspects of lte handover. This paper focuses on handover procedure in lteadvanced networks and proposes a smart forwarding mechanism to improve handover performance.
Analyzing x2 handover in lteltea konstantinos alexandris, navid nikaein, raymond knopp, and christian bonnet eurecom, biot, france email. Lte handover restriction list configuration mode commands exit. Today we will be talking about handovers from eutran to utran, from 4g to 3g. In soft handover macro diversity with selection combining is. Il permettra le transfert des donnes des hauts dbits, avec des portes plus superieures.
Lte s1 handover s1 handover lte mobile enodeb network. Nov 06, 2016 when lte system was developed one of the big technical feature from umts softsofter handover was missing from the architecture. An s1 handover is a fallback for scenarios where x2 interface is not available. Optimizing the parameters of handover in lte using son system by handling mobility robustness g k venkatesh dr. Before discussing about why lte skipped soft handover and only implemented hard handover, lets check the basic concept of softsofter handover. Dec 04, 2014 lte x2 handover x2ho call flow procedure lte enodeb handover over the x2 interface enghindi duration. This procedure may relocate the mme andor the serving gw. Lte s1 handover s1 handover lte mobile enodeb network core. More complicated probably the most complicated cases are the multi cell scenario among different technologies different rats. The research topic of this thesis which is lte handover performance evaluation.
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. Lte networks prefer using the x2 interface for performing inter enodeb handovers. Test measurement challenges and field environment test planning school of electrical engineering master. The senb issues a handover request message to the tenb. Jun 02, 2017 lte networks prefer using the x2 interface for performing inter enodeb handovers. Lte x2 handover sequence diagrams lte long term evolution.
Hard handover mechanism is adopted to be used in lte advanced. In an lte network, these two enbs can directly communicate with each other via the x2 interface, which differentiates the network from its precedents 2g and 3g. This paper discusses the lte handover procedures that are standardized in 3gpp release 8 and describes a new lte handover. Aug 31, 2012 coordinated multipoint comp transmission and reception is the key technique in lte advanced to improve the celledge throughput andor system throughput.
The simplest multi cell cases would be between two lte cells. Ims is the 3gpp voice over ip solution which is being deployed in the lte networks as the voice solution. Syntax description noforbidden interrat all cdma2000geranutranlocationar eaplmnididtrackingar. It means this is mainly for ue side aspect of handover process. Following is the overall and simplest form of lte lte handover procedure. Fast authentication during handover in 4g ltesae networks. There are many specific reasons why lte dropped altogether soft handover connectbeforebreak from the system design. Jun 03, 2017 the data path switching goes through several steps to accomplish a seamless handover. Lte x2 handover sequence diagrams detailed message flow analysis of lte x2 handovers eventstudio system designer sequence diagram based systems engineering tool.
Dec 04, 20 in case of intra lte handover using x2 interface the ue is source enodeb and is in connected stated and the goal is to move the ue to target enodeb. Introduction architecture couche physique couche mac plan lte. Command line interface reference, commands i q, staros release 20 6. We call this kind case as intrarat multi cell scenario. When a ue is camped on the lte network, it would need to fallback to the legacy 2g3g networks when coverage or capacity dictates. Optimized performance evaluation of lte hard handover algorithm. In the scenario described here serving gw is also unchanged.
In particular, x2 handover is introduced to allow neighboring. Following is the overall and simplest form of ltelte handover procedure. In this context, one of the main goals of lte is to provide fast and seamless handover from one. The second and third documents explain the procedures for x2 handover and s1 handover in an intralte environment, respectively. Lte, the handover procedure in lte and the deployme nt scenario of henb. Please visit our website in order to download the latest version. The second and third documents explain the procedures for x2 handover and s1 handover in an intra lte environment, respectively.
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 program gives a brief simulation model for lte network lte, an abbreviation for longterm evolution, commonly marketed as 4g lte, is a standard for wireless communication of highspeed data for mobile phones and data terminals. Lte x2 handover in eventtriggered handover procedures, each ue evaluates the event condition every time a new. Handover implementation in a 5g sdnbased mobile network. Lte, load balancing, interfrequency handovers, colocated frequency band, lisbon. Handover lte lte telecommunication orthogonal frequency. Lte ue event measurement reportingevent a1,a2,a3,a4,a5,b1,b2. A3based measurements and handover model for ns3 lte. Towards selforganizing mobility robustness optimization in inter. Pdf enhanced handover mechanism in long term evolution lte. Mar 30, 2012 few last articles were about handover in lte network. Handover between lte and 3g radio access technologies.
Pdf handover in lte networks with proactive multiple. Joint processing jp in comp technology provides multiple data transmission points for each user among multiple cooperated radio base stations. Mobileipp is our patented technology that matches the main protocol in use by 4g lte and depicted in the etsi. 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. Optimising handovers in enterprise small cell lte networks. Therefore, the lte sae should be more secure than the 3g network and especially should have a strengthened defense against the current attacks from the. The enodeb sends measurement control messages to the ue giving reporting thresholds. May 23, 2014 when lte system was developed one of the big technical feature from umts softsofter handover was missing from the architecture. 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. This document will provide the basic concept of lte handover and the. 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.
The ue receives the rrcconnectionreconfiguration message with necessary parameters i. Before discussing about why lte skipped soft handover and only implemented hard handover, lets check the basic concept of. From old enb to new enb, with or without using new mmesgw, with or without using x2 interface, and so on. Ueassisted measurements are made and reported by the ue to the network. In this approach, all the ho procedures at the ac are unnoticed by the rc network i. Create default bearer request imsi, msisdn, apn, serving gw address serving gateway sends create default bearer request message to the pdn gw. Points covered include a detailed description of various components of the radio interface.
In this case source and target cells are part of the same lte network. Load balancing via interfrequency handovers in lte networks. A3based measurements and handover model for ns3 lte budiarto herman, dmitry petrov, jani puttonen, janne kurjenniemi magister solutions ltd. Handover principles and handover measurements in lte. Lte handover restriction list configuration mode commands. Measurement based reporting used in lte to trigger handover.
Mobility types two types of handover procedure in lte for ues in active mode the s1 handover procedure no x2 interface between the two enodebs configured to initiate handover towards a particular target enodeb via the s1 interface the x2 handover procedure normally used for the interenodeb handover. In addition, some mobility manage ment issues such as handover scenario, mechanism for sea rching the henb in the closed subscriber group csg, cell reselection and handover decision parameters have a lso been described. Handover in lte networks with proactive multiple preparation approach and adaptive parameters using fuzzy logic control. The x2 handover procedure is performed without evolved packet core epc involvement, i. Sorry guys, today i dont have time to create abstract picture which we could use to start from. This book presents the technical characteristics of the two radio network interfaces of mobile 4g, lte and lte advanced, based on release 8, 9 and 10 of the 3gpp specifications. Consequently, we assume the same x2based handover ho procedure as for lte standard 7. By default, user equipment in the lte network detect suitable neighbor cells without the. In soft handover macro diversity with selection combining is selected. 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. Assumed cc management policies extracted from ynii11. Handover process in lte, lte handover tutorial teletopix. In softer handover, the nodeb can receive the signal in macro diversity with maximum ratio combining.