Bssmap handover detected the bsc informs the msc that the handover has been detected. By regulating four parameters from the handover procedure, and by introducing different traffic loads, frequency reuse and mobility patterns, while testing the results against a set of. Interrat handover procedure can be initiated in variety of ways. Pdf handover between wcdma and gsm long vu academia. The operations handover information form will be attached to the operations safety critical handover form when completed. A dualantenna based handover scheme for gsmr network. The purpose of the handover procedure it to preserve ongoing calls when the mobile station moving from one cell to another. Handover from utran to gsm can happen with or without prior measurements on target cell. Handover is the procedure that transfers an ongoing call from one cell to another as the users moves.
Gsm handover procedure handover is the procedure that transfers an ongoing call from one cell to another as the users moves through the coverage area of cellular system. Jun 03, 2017 lets examine the x2 handover in detail. Lte x2 handoverx2ho call flow procedure lte enodeb handover over the x2 interface enghindi duration. In order that the operation of the building continues in a smooth and efficient manner after handover it is important that information is available to the maintenance teams who may be called to attend to plant or. Pdf gsm handover optimization paul kabeya academia. Jan 02, 20 why handover required in gsm and its procedure posted on 2 january, 20 handover is the mechanism that transfers an ongoing call from one cell to another as a user moves through the coverage area of a cellular system. Handover procedure in lte network gl communications inc.
Handover preparation an overview sciencedirect topics. Pdf handover scenario and procedure in ltebased femtocell. Handover procedure may be initiated either by the ms or the bs. Handover management procedure in gsm network 2 during handover management procedure, when a mobile user travels from one area of coverage to another within a calls duration, the call is transferred to the new cells base station. The process by which this occurs is known as handover or hando its a critical process and if performed incorrectly handover. Gsm subsystems network subsystem the vlr also connects to. The handover reference was send in the encapsulated handover command message. The handover request acknowledge message includes a transparent container to be sent to the ue as an rrc message to perform the handover. The procedure for when a ue is leaving the eutran cell. We believe that this is the key reason of the latency incurred in the measurement procedure and cause the disconnection during the handover process. Before describing the above scenario we need to know three important terms. The term handover is more widely used within europe, whereas handoff tends to be use more in north america.
Masters programme, research on information and communication. Dualantenna based handover scheme 10 dualantenna system the conventional handover scheme is based on single antenna, and it should transmit both of the measurement report and encoded speech or. The following example will describe soft handover for best case scenario. The combined procedure is a combination of hard handover and srns relocation. Outgoing crew change personnel should obtain all other relevant documentation such as subordinates handover reports, log. This is because a single cell does not cover the whole service area e.
The same principles apply in the handover procedures for eps as well. Otherwise in other rrc states the ue does reselection to move to other radio access technology. Inter rat handover target handover from an eutran to a different rat. Handover, if required, takes place, as discussed in the earlier case. This form of handover is supported within gsm and a neighbour list was established to enable this occur easily. The cell reselection procedure used in ready state shall minimise the cell changes. In this paper the handover procedure in femtocell network is investigated. Handover is important in view of the deadlines stated in. This form of gsm handover occurs if it is required to change the frequency being used by a mobile because of interference, or other reasons. The procedure for when a ue is entering the eutran cell. The cells in the neighbour list called in cdma neighbouring set are checked more frequently than the rest and thus a handover with a neighbouring cell is more likely, however a handover with others cells outside the neighbor list is also allowed unlike in gsm, is6damps, amps, nmt, etc. Ps handover procedures for gsm were developed with the basic principles of two main phases. The s1handover procedure is performed between two enbs without the x2 interface. The s1 handover procedure is performed between two enbs without the x2 interface.
We look at the x2 handover signaling procedure through sequence diagrams that focus on different aspects of the procedure. In cellular telecommunications, the terms handover or handoff refer to the process of transferring an ongoing call or data session from one channel connected to the core network to another channel. The standard supports a variety of profiles ho principles are similar in various types of systems. When ue reaches end of coverage area for umts services, it can handover to a 2g service like gsm if the ue supports multiple rat. Outgoing crew change personnel should obtain all other relevant documentation such as subordinates handover reports, log sheets, logbooks, memos, reports etc. This form of gsm handover occurs if it is required to change the frequency being. One of the main goals of lte or any wireless system for that matter is to provide. If the ms is in dedicated mode, then the changes from one cell to another is performed according to the networkcontrolled handover procedures. However a single cell has a maximum service area of approximately 23 miles 35 km for each antenna. Basic handover procedure not requiring the establishment of a circuit connection between msca and mscb 3. The visited msc vmsc, to pass data needed for certain procedures i. Handover procedures the handover of refurbished areas or new buildings to the university is a critical point in a contract process. It may however also be performed for other reasons such as system load control. Basic handover procedure requiring a circuit connection between msca and mscb 2.
Gsm systems require a procedure known as a handover to maintain the continuity of the call. The x2 handover is used when direct connectivity between source and target enbs exists. There are four basic types of handoffs in gsm network. When handover is initiated by the ms, the triggers and conditions are defined by the serving bs and a handover initiation message is sent by the ms to begin the handover procedure. Lte x2 handover sequence diagrams lte long term evolution. Handover is the shifting of call from one cell to other when the person on call is moving. Gsm to umts handover procedures networking something. As the gsm 2g network is normally more extensive than the 3g network, this type of handover does not normally occur when the mobile leaves a coverage area and must quickly find a new base station. Handover procedure an overview sciencedirect topics. Apr 20, 2015 gsm systems require a procedure known as a handover to maintain the continuity of the call. Handover management in gsm cellular system jahangir khan school of computer science pafkiet, pakistan air force base. The process by which this occurs is known as handover or handoff.
In fdd, the cells in the active set are involved in soft handover. Various handover management techniques in gsm cellular. User information is sent all the cell belongs to active set. Mostly it is a confirmation of the actual physical delivery of work that is then accessible to the customer. Why handover required in gsm and its procedure posted on 2 january, 20 handover is the mechanism that transfers an ongoing call from one cell to another as a user moves through the coverage area of a cellular system. Gsm works on three frequencies 900 mhz, 1800 mhz and 1900 mhz. In case of dispute, the reference shall be the printing on etsi printers of the pdf version kept on a specific network drive. Gsmgprs supports packet data together with cs traffic, with rates up to 171kbps handover in gprs is strongly aligned to gsm handover qos is the main issue in handover of gprs.
Digital transmission was used rather than analog transmission in order to improve transmission quality, system capacity, and coverage area. In satellite communications it is the process of transferring satellite control responsibility from one earth station to another without loss or interruption of service. Let us understand each of these causes or triggers of gsm handover. Basic handover procedure requiring a circuit connection between msca and 3g mscb gsm to umts 2. Intra enb handover source handover from one sector to another managed by the same enb. In this case source and target cells are part of the same lte network. Pdf wcdma handover principle and relevant parameters. Wcdma 3g irat interrat handover principle and its parameters. Handover report what is the handover report and what is its purpose the handover report is used to formally confirm if work or performance were delivered to the customer. The adoption of a simple traffic balancing rule on an adjacency basis deals with spatial traffic variability, while the discrimination of several time periods through differentiated parameter settings copes with. Catherine mulligan, in epc and 4g packet networks second edition, 20. Mobile continuously transmits measurement reports signal strength, distance, traffic volume. By regulating four parameters from the handover procedure, and by introducing different traffic loads, frequency reuse and mobility patterns, while. The received signal level is used as trigger point for the handover.
Old conceptwhenever mobile station is connected to 1 basestation and there is a need to change to anotherbase station, it. Why handover required in gsm and its procedure teletopix. Various handover management techniques in gsm cellular system. Gsm association nonconfidential official document ir. Either way, handover and handoff are the same process. The actual call is identified using the handover reference. Handover scenarios in gsm systems adio systems without modern mobile r e inconceiv er functionality ar v handoer a v he capability to hand o able. Subsequent handover from mscb back to msca without. Jun 16, 2011 soft handover in practice is a complex technique.
The handover procedure is divided into four phases. Inter msc handover call flow gsm inter msc handover call flow highway gsm coverage gsm mobile vienna target bethesda source mobile vienna cell vienna bsc vienna msc vlr bethesda msc vlr bethesda bsc bethesda cell eventstudio system designer 4. To transmit the speech over the radio channel in the stipulated time, the ms codes it at the rate of kbps. There may be coordination of the idle and dedicated mode procedures used for circuitswitched services with. It is the only wage er v s full co antee umts customer om. Gsm handover was an area to which particular attention was paid when developing the standard. Old conceptwhenever mobile station is connected to 1 basestation and there is a need to change to anotherbase station, it is known as handover. Basic handover procedure not requiring the establishment of a circuit connection between msca and 3g mscb gsm to umts 3. This occurs when neighbour cell signal level becomes more than serving cell to the value of about 3 to 6 db. The purpose of the handover procedure it to preserve ongoing calls when the. Such a kind of handover is performed to optimize the traffic load in the cell or to improve quality of a connection by changing carrier frequency.
Subsequent handover from mscb back to msca without circuit. The maps x2ap test tool is designed with specific test cases, as per lte 3gpp mobile standards. Optimization of handover margins in gsmgprs networks. T om a umts system to mobile phone fr a gsm system, for example, is a basic equisite for the economic success er pr y to guar a of umts. Types of gsm handover within the gsm system there are four types of handover that can be performed for gsm systems. Handover process in lte, lte handover tutorial teletopix.
Handover basically means changing the point of connection while communicating. Subsequent handover from mscb back to 3g msca gsm to umts 4. Handover procedure there are two types of handover procedure in lte for ues in active mode. Access burst, handover reference the bsc receives the handover accept from the terminal. 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. 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 is the procedure that transfers an ongoing call from one cell to another as the users moves through the coverage area of cellular system. Irat handover from utran to gsm can be possible without more. The bsc transcodes the speech to 64 kbps and sends it over a land link or a radio link to the msc. Nov 05, 20 handover from utran to gsm can happen with or without prior measurements on target cell.
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