This tutorial explains the procedure of hard and soft handovers in 3g wcdma or 3g umts. Hard handover means that all the old radio links in the ue are removed before the new radio links are established. Umts handover control telecom knowledge and experience. This form of handover occurs when the base station hands off the ue by passing it the details of the new cell to the ue. Jul 09, 2014 it is a handbook of umtswcdma call flows for handovers. What is handover handoff changing the point of connection while communicating. Irat basics and interrat handover with example of wcdma rat to gsm rat handover, refer irat handover.
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. At first i will center the study in the objectives and main characteristic of. There are two further divisions of this category of handover. If so, share your ppt presentation slides online with. In this paper we briefly touch upon the procedures executed by the user equipment ue and the various network elements to provide the handover services requested by the ue. Handover gsm umts presentation free download as powerpoint presentation. Oct 28, 2017 this tutorial explains the procedure of hard and soft handovers in 3g wcdma or 3g umts. The present document provides a mechanism giving reliable transfer of signalling messages within the 3gpp system.
The research topic of this thesis which is lte handover performance evaluation based on power budget handover algorithm, focuses on different combinations or settings of hom and ttt values to evaluate the handover performance based on reference signal received power rsrp measurement within certain. The handover to wifi network has become popular due to following benefits of wifi based networks. Pdf umts irat handover analsysis jachang ma academia. X2 handover is initiated if the if the target cell is served by the same mme as the current cell the message includes ue context information that identifies the ue. Checklist for job handover if i complete this checklist do. The steps in the procedure of soft handover are explained. Feb 19, 20 soft handover make before break new connection is activated before the old is broken used in umts to improve the signal quality uplink and downlink signals may be combined for better signal a mobile may in umts spend a large part of the connection time in soft handover better connection reliability more seamless handover. 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. This completely revised and updated edition of the highly successful umts signaling provides a deep insight into all aspects of umts signalling. It is a handbook of umtswcdma call flows for handovers. It also mentions wlanwifi to umts3g handover with message flow diagram.
Before describing the above scenario we need to know three important terms. Optimization of soft handover parameters for umts antenna. An introduction about intersystem handovers and cell changes irat handover analysis troubleshooting irat ho using dashboard kpis how to find an irat handover and cell. Femtocell handover soft handover vs softer handover lte to wlan and wlan to lte handover umts to wlan and wlan to umts handover mobile wimax handover as per ieee 802. One of the key aspects of any cellular telecommunications systems is the handover from one cell or sector to another. Dukic2 1 mobtel srbija bk ptt 2 electrical engineering faculty, belgrade i introduction mobility is the main advantage of mobile cellular systems. This definition was formed before the advent of umts. When only ps service exists, adopt cell reselection process of ps service handover. Comparison between soft handover and hard handover in. In order not to confuse the jargon, the definition was kept. By definition, handover means transfer of user connection from one radio channel to other. Nov 26, 2012 this tutorial describes lte handover types and procedures. Within umts architecture, the rrm entity is responsible for the utilization of the air interface resources and it covers power control, handover, admission control, congestion control and packet. All the other handover models follow the same modeling technique.
The soft handover procedure is composed of several functions. Performance evaluation of voice handover between lte and umts a research report submitted to the faculty of engineering and the built environment, university of the witwatersrand, in partial fulfilment of the requirements for the degree of master of science in engineering johannesburg, 2011. Ppt 3g umts handover issues powerpoint presentation. The successful trial, deployment, operation and troubleshooting of 3g or umts infrastructures and. Soft handover and downlink capacity in umts network, tomic. The successful trial, deployment, operation and troubleshooting of 3g or umts infrastructures and applications is the. Pdf the effect of handover on umts services researchgate.
Formal verification of lteumts and ltelte handover. Like other mobile networks lte also have big challenges when it comes to mobility areas like handover and reselection. Test measurement challenges and field environment test planning school of electrical engineering master. There are following categories of handover also referred to as handoff. Universal mobile telephone system umts is a third generation mobile and wireless communications standard which is also being developed into a fourth generation technology. The following example will describe soft handover for best case scenario. February, 28th 2005 overview in this document i make a study of third mobiles generation systems. Soft handover and downlink capacity in umts network igor a. These handovers are given a variety of names including interrat handover as they are handing over between different forms of radio access technology, intersystem handover, and umts gsm handover. This iur open interface carries both signaling and traffic information for example during a. Abstract universal mobile telephone system umts is a third generation. They are used for providing mobility in cellular architectures. It is a handbook of umts wcdma call flows for handovers. Comprehesive coverage of umts 3g news, licensing, business developments, 3g wcdma telecommunication technology, multi media mobile phones and future communications.
Pdf universal mobile telephone system umts is a third generation mobile and wireless communications standard which is also being developed into a. All the smart mobile devices come with wlan support wifi networks are low cost. Handovers are an important part of every cellular communication system. Ensure that the handover process will be implemented across the organisation. A free powerpoint ppt presentation displayed as a flash slide show on. Comparison between soft handover and hard handover in umts. Umtsfdd is an acronym for universal mobile telecommunications system umts frequencydivision duplexing fdd and a 3gpp standardized version of umts networks that makes use of frequencydivision duplexing for duplexing over an umts terrestrial radio access air interface. Handover between lte and 3g radio access technologies. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Performance evaluation of voice call handover between umts. The umts world is an 3g mobile system news and information provider. The chapter structure has been reworked for improved usability for readers, as well as including many new features and updates. This form of handover is supported within gsm and a neighbour list was established to enable this occur easily. Having selected a suitable base station the handover takes place, but without any time synchronisation having occurred.
Pdf mobility is an important factor in cellular networks so handover should be used to avoid the termination of call when user signal travel. In 4, an architecture for umts wimax is introduced based on tight coupling interworking and using a single radio ms. Hence, the latency for handover from umts to gprs and gprs to umts does not very too much in both. Lte changed the way traditional mobile network were working. The ue uses the neighbour list provided by the umts network to monitor and select a suitable candidate base station. This document is originally edited by justin ma and it is free to share to everyone who are intereste. Handover in particular is more complicated in lte as lte has. The lte to umts handover proverif model is used here for describing how the security properties specified in section 5. In umts systems different handover types have been introduced to cope also with other requirements as load control, coverage provisioning and offering quality of services. A user of a mobile phone will be moving continuously.
In a cell, interrat handover can only be triggered by 3a or 3c event, which is controlled by interrat handover tactic rathotactic. User information is sent all the cell belongs to active set. This tutorial describes lte handover types and procedures. This document is originally edited by justin ma and it is free to share to everyone who are interested. Soft handover make before break new connection is activated before the old is broken used in umts to improve the signal quality uplink and downlink signals may be combined for better signal a mobile may in umts spend a large part of the connection time in soft handover better connection reliability more seamless handover. A1 contains an excerpt of the proverif model used to verify the lte to umts handover procedure. In such a situation, the mobile connection should also remain intact especially if the user is currently using the phone. In this paper we present a soft handover algorithm for wide band cdma based eumts networks and the associated power control algorithm. Interrat intersystem umts gsm handover in many instances it is necessary for the umts radio access network to handover to the 2g gsm network. Using compressed mode handover the ue uses the gaps in transmission that occur to analyse the reception of local gsm base stations. Ue reported rrc downlink signal quality measurements uplink signal quality measured at the enodeb enodeb picks the target cell id for the handover.
When umts came this definition was no longer valid. Leaving circuit switched technology far behind lte became the first allip mobile network. Umts in transition from one cell to another communicates with both base stations node b in umts simultaneously. Basic gsm to umts handover procedure not requiring the establishment of a. Dowlink soft handover gain in umts networks under different power control conditions y chen and l g cuthbert queen mary, university of london, united kingdom abstract in this paper, the downlink soft handover gain is analysed in umts networks under three different power control situations. Seamless hard handover means that the handover is not perceptible to the user. The average latency for handover from umts to gprs in overlapping area is 119 ms and in nonoverlapping area is 1. Wcdma wideband code division multiple access technology introduces other kind of handovers, namely.
1419 1075 1582 1580 229 773 328 201 299 48 154 259 1325 1332 1011 29 610 737 750 1450 729 1235 546 383 626 585 292 781 1131 1246 386 415 233 283 186 1020 661 948 324 805 1354 378 1167