Handover principles and handover measurements in lte. 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. Prevention of desynchronization attack in 4g lte networks. A communication system, a network handover processing method and a network handover processing apparatus are disclosed. Selfoptimization of handover parameters in lte networks veronique capdevielle, afef feki alcatellucent belllabs, france email. Consequently, high levels of interference and low sinr can be expected near the cell edge.
Handover through the x2 interface is triggered by default for intra lte mobility unless there is no x2 interface established or the source enb is configured to use s1based handover. Le crc du message dci est embrouille par lidentifiant rarnti. Dl data packets are forwarded from the senb to tenb via the sgw during the handover as the sgw is not changed here. X2 handover is performed between a source enb and a target enb through the x2 interface. Download scientific diagram handover key management using crnti. One of the other numbers which you would very frequently come accross is rnti. Download as pptx, pdf, txt or read online from scribd. Test measurement challenges and field environment test planning school of electrical engineering master. The chapter presents an overview of the several considered load control solutions and gives a detailed description of the standardized extended access class barring solution. In an lte network, these two enbs can directly communicate with each other via the x2 interface, which differentiates the.
This course focuses on the lte air interface and provides a detailed analysis of the structure and features of the physical layer, as well as the layer 2 and 3 protocols, before explaining how these are used in the operation of the radio link from initial attach, through service delivery and. Even though 4g network provides security, there are loopholes which lead to several attacks in 4g network. Lte security, protocol exploits and location tracking. This logical channel information is further carried over transport channel bch or carried by dl. A comprehensive reference on the call procedures of 4g ran and core networks, lte signaling, troubleshooting and optimization describes the protocols and procedures of lte. Coordinated multipoint comp transmission and reception is the key technique in lteadvanced to improve the celledge throughput andor system throughput. Please leave your comment if you have a question or suggestion. When the reporting threshold condition is fulfilled, the ue sends handover measurement reports to the serving enodeb. Prevention of desynchronization attack in 4g lte networks using.
There are four identities that a mobile searches for in the downlink control information dci in the pdcch. The x2based handover procedure is illustrated in figure 4. Following is the overall and simplest form of lte lte handover procedure. C rnti to confirm the handover to the target enb to indicate that the handover procedure is completed for the ue. Cell radio network temporary identifier crnti allocation. Zero correlation zone config, prach frequency, prach frequency offset. We look at the x2 handover signaling procedure through sequence diagrams that focus on different aspects of. The handover procedure in this section is very similar to that in the previous section intra lte handover using the x2 interface, except the. The temporary c rnti is promoted to c rnti for a ue. Allocate c rnti a new c rnti is assigned to the ue. As the name implies, it is a kind of identification number. Lte ue can detect intra lte neighbors without neighbor lists which simplifies network management.
Rnti stands for radio network temporary identifiers and guti stands for globally unique temporary ue identity. Rrc context including the c rnti of the ue in the source enb, asconfiguration, erab context and physical layer id of. Intra lte 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. Lte handover latency calculation access node january 21, 2018 january 21, 2018 admin lte, tdd lte, tech fundas in a cellular system, handover can be defined as a procedure to transfer a user equipment ue and its context from a source cell to a target cell when source cell signal becomes bad so it handover the ue to target cell to continue. In case of dispute, the reference shall be the printing on etsi printers of the pdf version kept on a specific network drive within etsi. Individual copies of the present document can be downloaded from. When lte system was developed one of the big technical feature from umts softsofter handover was missing from the architecture. Lte uses universal frequency reuse n1 without soft handoff. Reducing the effects of pingpong handover in intra lte networks using fuzzy logic eng. Master information block mib ues download the mib from the broadcast channel. The v2i communication is better than the v2v communication for propagating safety messages at critical regions like intersections where the safety messages must be delivered to surround vehicles with low latency and loss, since. Rnti stands for radio network temporary identifier. In this context, one of the main goals of lte is to provide fast and seamless handover from one.
In case of dispute, the reference shall be the printing on etsi printers of the pdf version kept on a. The core objective of 3gpp long term evolution lte is to provide a secured communication and high data rate for 4g users. Selfoptimization of handover parameters in lte networks. Direct vehicletovehicle v2v and vehicletoinfrastructure v2i communications have been popularly considered for safe driving of manned or unmanned vehicles. Lte handover latency calculation access node techplayon. In this experiment, we will experiment with a longrunning. Contention based access for machinetype communications over lte. Ra rnti range specifies the range of rnti values that are assumed to be ra rntis when decoding pdcch transmissions. Uec picks a distinct preamble so it succeeds in the random access procedure. The x2 interface is used to perform a handover between enodeb. At runtime, in debugging builds, if this condition is not true, the program prints the source file. Lte enodebs can directly communicate with other enodebs on the x2 interface. This chapter describes and discusses the current longterm evolution lte random access procedure and the radio access network load control solution within lte lte a.
Before discussing about why lte skipped soft handover and only implemented hard handover, lets check the basic concept of. Interoperable ue handovers in lte radisys white paper 6 7. Prepare the handover command message rrc connection reconfiguration. Lte downlink and uplink transmissions are organized into radio. 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. There are many specific reasons why lte dropped altogether soft handover connectbeforebreak from the system design.
The system information is very essential and the same is broadcasted by lte enb over logical channel bcch. Lte s1 handover s1 handover lte mobile enodeb network. This parameter is needed to unambiguously decode the contents of dci format 1a. 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. Lte system information blocksmib,sib1,2,3,4,5,6,7,8,9,10,11. Est implique dans le transfert intercellulaire handover. Apr, 2010 by lteworld in blog, handover, intra, intra eutran handover, sgw, eutran, enb, lte, mme. Kinan ghanem dr adnan motermawy dr haysam alradwan abstract improving system performance in terms of data rate, latency, mobility and cost is the scope of long term evolution lte system. Lte rnti vs gutibasics of rnti identifier and guti. Ims is the 3gpp voice over ip solution which is being deployed in the lte networks as the voice solution. Lte x2 handover between enodebs served by the same mme. A cell radio network temporary identifier c rnti allocation method and device are disclosed.
Handover process in lte, lte handover tutorial teletopix. Analyzing x2 handover in lte lte a konstantinos alexandris, navid nikaein, raymond knopp, and christian bonnet eurecom, biot, france email. Us9655011b2 communication system, network handover. In case of dispute, the reference shall be the printing on etsi printers of the pdf version kept on a specific network drive. This page on lte rnti vs guti describes basics of rnti identifier and guti in lte system. Rnti is used, so that ue original identity can be hide, so that no one can detect the ue, but as a identity ue can also send imsi or imei, in. It means this is mainly for ue side aspect of handover process. Handover between lte and 3g radio access technologies. Dl rnti based pdsch bler, wherein the determined decoding timer value corresponds to. Rnti radio network temporary identities are used as ue identities within the utran and in signalling messages between ue and utran. With the introduction of lte came the development of a new radio technology based on ofdma scfdma. 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. If the target cell id is known by enodeb, it will proceed with the handover.
Now lets jump into detailed technical aspects of lte handover. Lte network enhancement for vehicular safety communication. The handover report type can be signalled with values of either handover too early or handover to wrong cell, i. This channel contains information about the location of the downlink and uplink carrier configuration. In particular, x2 handover is introduced to allow neighboring. 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 is an abbreviation for longterm evolution, which is a fourth generation mobile communication. Lte rnti vs gutibasics of rnti identifier and guti in lte. When a ue is camped on the lte network, it would need to fallback to the legacy 2g3g networks when coverage or capacity dictates. Two of them uea and ueb happen to pick the same preamble. 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. Similar to an s1based handover, the procedure is composed of a. X2 protocol stack x2 has exactly the same stack as s1, simplifying data forwarding operation. The method includes receiving, by a target evolution nodeb tenb, identity information sent from a user equipment ue, the identity information being allocated to the ue by a source evolution nodeb senb.
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