This paper discusses the lte handover procedures that are standardized in 3gpp release 8 and describes a new lte handover. Before describing the above scenario we need to know three important terms. Dl data packets are forwarded from the senb to tenb via the sgw during the handover as the sgw is not changed here. Though i assumed you have a very little or zero understanding on 2g and 3g technologies like gsm. This page on femtocell tutorial covers femtocell handover procedure.
The third generation network, known as 3g, is the oldest technology of the group. Visualether protocol analyzer wireshark based visual protocol analysis and system design reverse engineering tool. Lte x2 handover in eventtriggered handover procedures, each ue evaluates the event condition every time a new. Dahlman, lte 3g long term evolution, expert radio access technologies ericsson. Handover principles and handover measurements in lte. Pdf enhanced handover mechanism in long term evolution lte. A further step in the 3g mobile cellular system evolution was. Comprehesive coverage of umts 3g news, licensing, business developments, 3g wcdma telecommunication technology, multi media mobile phones and future communications. Saboji contents introduction long term evolution in 3gpp architecture handover management in 3g lte conclusion references introduction the third. Within 3g umts there are several forms of handover including hard handover, soft handover, a form of handover called softer handover and a handover from one radio access technology to another called interrat handover. Handover process in lte, handover in 4g telecom, lte handover types, lte handover call flow, intra enodeb handover lte, lte handover events, lte handover tutorial, handover in lte, sharetechnote, handover in lte 4g parameter. Network architecture for lte and wifi interworking 1. Back in 2014 i was musing about that the time has come for network operators to introduce a feature to handover an ongoing 3g connection to lte. Handover in lte lte telecommunication transmission.
In the lte project of netsim source codes modifications are done to perform lte x2 handover. Handover between lte and 3g radio access technologies. Also 3g network operators need to define the neighbor lists but it is possible for ue to detect the new cells outside neighbor list which makes. This refers to the generation of network technology. When lte system was developed one of the big technical feature from umts softsofter handover was missing from the architecture.
Abstract fast and seamless handover are also weighty issues in 3g lte systems. In fdd, the cells in the active set are involved in soft handover. Lte x2 handover sequence diagrams detailed message flow analysis of lte x2 handovers eventstudio system designer sequence diagram based systems engineering tool. The standardization of lte system has been completed in march 2009 by the 3gpp. Sae systemarchitectureevolution is the corresponding evolution of the gprs 3g packet core network evolution.
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. Without the feature a device is stuck in 3g unless the radio bearer is released and the mobile can reselect back to lte autonomously. 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. This tutorial has been designed for audiences with a need to understand the lte technology basics in very simple terms.
The umts world is an 3g mobile system news and information provider. There are many specific reasons why lte dropped altogether soft. Handover process in lte, lte handover tutorial teletopix. Lte doesnt support circuit switched calls, because it is an ip based network. It mentions types of femtocell handover as per 2g, 3g, 4g, lte, umts, wimax, gsm standards. Although crosslayer optimization and mobility prediction are well known. Whether you are an experienced telecom engineer or a beginner, this website is vital for those who wish to expand their knowledge of this developing field. Normally there are two type of handover approach available in mobile networks. The senb issues a handover request message to the tenb. Pdf highspeed data applications over wireless networks have been growing rapidly in recent years. At ctia 2010 in las vegas, cisco will again be demonstrating a live handover from both 3g to 4g and 4g to 3g with seamless mobility for mobile video. The tenb checks for resource availability and, if available, reserves the resources and sends back the handover request acknowledge message.
Your call will then continue on the 3g network, but now as one cs voice call. For me and those who frequently tether their pc while on the move, this is an important feature when the network makes a handover of an ongoing connection from. Intralte intramme sgw handover using the x2 interface. In this video we are going to discuss about lte handover overview interintrainterrat do like it, share and subscribe the channel if you havent yet. Interdomain handover technologies in lte for voice volte. User information is sent all the cell belongs to active set.
An s1 handover is a fallback for scenarios where x2 interface is not available. This form of handover is supported within gsm and a neighbour list was established to enable this occur easily. The first live 3g to 4glte handoff cisco demonstrated the first live 3g to 4g handover in the industry at mobile world congress. Random access procedure the ue establishes an rrc connection with the lte enodeb. Interoperable ue handovers in lte radisys white paper 6 7. Ue decides to move back to lte network and sends a connection request to lte network. You can also click on the message titles to see the complete structure of the messages. Network architecture for lte and wifi interworking. In comparison, ues are the same, different radios, on one end lte, and into the future a 5g radio. Pdf over the past decade, there have been great interests in cellular and fixed radio access technologies for providing mobile, nomadic and fixed. For me and those who frequently tether their pc while on the move, this is an important feature when the network makes a handover of an ongoing connection from lte to 3g. 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 research topic of this thesis is handover from lte to 3g cellular networks, which is a. Thus applications dont even come to know about this handover.
Introduction handover ho is key procedure for ensuring that users can move freely within. In such networks, the mobile phones fall back to 2g or 3g networks that support circuit switch calls. This procedure 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. Lte networks prefer using the x2 interface for performing inter enodeb handovers. We look at the x2 handover signaling procedure through sequence diagrams that focus on different aspects of the procedure. If the srvcc is supported, a set of messages are exchanged, and the voice call is transferred handover from lte ims to cs domain of the 2g 3g network. This and two subsequent documents will discuss the handover procedure required when a ue, still being served through the lte network it accessed, disconnects from its current serving cell, and connects to a new serving cell within the same tracking area ta as the ue travels as defined as emm case no.
The packet trace file can be accessed from the results window to understand the various packets involved in the handover process. The maps x2ap test tool is designed with specific test cases. A mobility management technique with simple handover prediction. Long term evolution lte is the 4 th generation cellular mobile system that is being developed and specified in 3gpp as a successor of umts. If the srvcc is not supported, the call is dropped as soon as it leaves the lte coverage area.
Old connection is broken before new connection is activated. When describing smartphone data networks, you commonly hear the terms 3g, 4g, and lte. One of the key aspects of any cellular telecommunications systems is the handover from one cell or sector to another. The circuit switched fallback, or csfb, is a service handover procedure, of lte protocol, devised to deliver voice and sms to lte devices with a circuit switch network 3g or 2g. Test measurement challenges and field environment test planning school of electrical engineering master. Intralte intramme sgw 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. Two types of handover procedure in lte for ues in active mode the. As the gsm 2g network is normally more extensive than the 3g network, this type of handover does not normally occur when the ue leaves. Handover occurs when difference value is equal to 3 on y axis which is between 30.
This tutorial will give you enough understanding on lte technology from where you can take yourself at higher level of expertise. Llttee qquuiicckk gguuiiddee llttee oovveerrvviieeww 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. The research topic of this thesis which is lte handover performance. Pdf of the x coordinate of all users in one simulation. Handover procedure in lte network gls maps designed for x2 application protocol x2ap is used to coordinate handovers and perform load management between enodeb evolved node b network elements source enodeb and target enodeb. Handover mechanisms in 3gpp long term evolution lte. Fast handover in cellular networks with femtocells ayaskant rath.
The following example will describe soft handover for best case scenario. The legacy handover procedures in 3g and lte systems were originally designed for handovers between. Lte to 3g circuit switched fallback lte to3g circuitswitched fallback. Handover is process of change of resources when users mobile call is in progress. Pdf soft handover issues in radio resource management.
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