Target enodeb interfaces successful handover lte mobile. The ues also obtain uplink timing information from the initial handshake. The container includes a new c rnti, tenb security algorithm identifiers for the selected security. Both uea and ueb assume that the assignment is for them as both ues think they have been assigned temporary c rnti 1. The cell random network temporary identifier c rnti. The handover command message includes the newly allocated c rnti, the possible start time, and sib of the target enodeb. The longterm evolution lte is the newly adopted technology to offer enhanced capacity and. The source gnb triggers the uu handover by sending an rrcreconfiguration message to the ue, containing the information required to access the target cell, that is, the target cell id, the new c rnti, and the target gnb security algorithm ids for the selected security algorithms.
Technical specification for uut interface of lte based broadband pdf, user and service manuals from. Provided is a method for receiving, by a terminal, a singlecell pointtomultipoint scptm service in a wireless communication system. In this case, ue will try something like followings. The temp c rnti is promoted to c rnti for a ue which detects ra success and does not already have a c rnti. This allows the ue to access the target enb faster. Crnti can be reallocated when a ue accesses a new cell with the cell update procedure. During the handover execution phase, the ue uses the c rnti that was allocated by the target enb during the handover preparation phase. To address the issue of packet loss, an enhancement is introduced, in release 21. A survey of handover management in ltebased multitier. Lte prach presentation free download as powerpoint presentation. 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. In this experiment, we will experiment with a longrunning file download from a notional internet server to a mobile handset.
This is kind of a identification number and this number will help to identify a particular radio channel message. Uea ueb ue c enodeb lte random access procedure lte random access procedure is used by the ues to initiate a data transfer. Performance comparison of dual connectivity and hard handover. Packet aggregation for machine type communications in lte. Handover between different radio technology networks, for example gsmumts and umts well look at intra lte handovers with x2ap signaling and s1ap signaling first, then interrat handovers in lte i. Rnti stands for radio network temporary identifier. Individual copies of the present document can be downloaded from. Soc classification level 116 nokia siemens networks case.
Ue will use c rnti while it is in commuincation status. Lte rach procedure free download as powerpoint presentation. The c rnti distribution method includes the following steps that under the condition that the ue aggregates the resources of. Handover request receive s1 teid ul admission control with erab qos qci, arp target enb reserves rrc resource and allocates a new c rnti e. The terminal may store a scptm rnti corresponding to an interested scptm. Compare the reencoded message with the original coded dci candidate. The presence of ip connectivity between the serving gw and the source enodeb, as well as between the serving gw and the target enodeb is assumed. Figure 6 shows how a c rnti is allocated and to which layer the c rnti is applied to. By default, the lte to wifi handover completion happens when create session response is sent on the wifi tunnel. The target enb verifies the c rnti sent in the rrc connection. Apr 10, 2010 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. Tacs in the united kingdom, c 450 in west germany, portugal and south africa, radiocom 2000 in. These steps can be broadly classified as following.
Next a comprehensive survey of state of the art handover optimization solutions in 3gpp lte lte a home enodeb handover management is presented which includes the actual version of 3gpp lte lte a henb handover procedure. Ue will use p rnti if it is in idle mode and it is at the po paging occasion subframe. Once arrived at the source enb, dl packets during the handover are forwarded to the target enb through the forwarding bearer, and buffered there until the ue. Cell radio network temporary identifier crnti allocation. Dec 04, 20 the tenb checks for resource availability and, if available, reserves the resources and sends back the handover request acknowledge message including a transparent container to be sent to the ue as an rrc message to perform the handover. Phich ack the enodeb accepts the transmission from the ue and acknowledges it with a hybrid arq ack. This message carries the handover command message rrc connection recon. Lte s1 handover s1 handover lte mobile enodeb network core. Wo2016111589a1 method and apparatus for controlling. Lte network implementations utilizing different cell phone. Prepare the handover command message rrc connection reconfiguration request this message includes the rach preamble that needs to be sent to the terminal. This document will provide the basic concept of lte handover and the. The terminal receives a list of available scptm services from a serving cell, the list of available scptm services including scptmrntis corresponding to the available scptm services.
Last but not least base station exchange has to be accelerated to achieve appropriate system performance. Handover process in lte, lte handover tutorial teletopix. It can also include a set of dedicated rach resources, the. Aug 20, 20 ues in the cell are uniquely identified by their c rnti.
Lte handover latency calculation access node techplayon. The gnb assigns different c rnti values to different ues. With the introduction of lte came the development of a new radio technology based on ofdma scfdma. Received ho command to target pcell 6, ncc 0 random access transmission. Configures lte to s2bgtp handover completion timeout in multiples of 100 milliseconds. Mobility and handover management for heterogeneous networks in. Prnti sirnti rarnti crnti tcrnti spscrnti ccrnti in 5g. This page on lte rnti vs guti describes basics of rnti identifier and guti in lte system. Crnti is a 16bit value that uniquely identifies a ue when. Rnti stands for radio network temporary identifiers and guti stands for globally unique temporary ue identity. Pdf lte security, protocol exploits and location tracking.
Nemo outdoor qualcomm vs samsung shannon 333335355. This course builds on the information provided in lte system engineering in order to equip you with a concise knowledge of the lte eutran. Then, it allocates crnti value that the ue needs to use when. This sequence diagram describes the tale of three ues uea, ueb and ue c that are powered on at the same time. The cell random network temporary identifier c rnti, rnti for short from here on is a phy layer identifier unique per device within a given cell. Position data the position of the ue is written to the. Uemeasurements the rsrp and rsrq reported values are written to the. Any failure caused by other than two mentioned above case 1, 4 and others.
It is the communication means of smartphones that send and receive all of the private date of individuals. If the measured 708 dl c rnti based pdsch bler is low e. Contention resolution is based on either c rnti on pdcch or ue contention resolution identity cri on dlsch once the msg3 transmitted, ue starts maccontentionresolutiontimer broadcast by. The source enodeb sends a handover command to the ue. Lte is a trade mark of etsi currently being registered for the benefit of its members and of the 3gpp. Lte security, protocol exploits and location tracking.
Soc classification level 116 nokia siemens networks case study call drop due to from radio 101 at politehnica university bucharest. Cell rnti c rnti is a unique identification used for identifying rrc connection and scheduling which is dedicated to a particular ue. Lte rnti vs gutibasics of rnti identifier and guti. Longterm evolution lte is a fourthgeneration mobile communication technology implemented throughout the world. This means the last 16 decoded bits constitute the c rnti. Lte prach presentation computer data data transmission. Lte security and protocol 2016 shmoocon proceedings. The handover request acknowledge message includes the newly allocated c rnti and other possible parameters such as access parameter, and rnltnl information for establishing a forwarding tunnel. Technical specification for uut interface of lte based broadband pdf, user and service manuals from manualsm4. Jan 21, 2018 in lte, handover mobility support for ues in ecmconnected handles all necessary steps for handover procedure. Download technical specification for uut interface of lte. The information includes target cell id, kgnb, c rnti of the ue in the source gnb, rrm. An enb is responsible for allocating radio resources to ues on uplink and downlink.
Handover to preamble time lte intra and interrat cell reselection uplane interruption time. Handover preparation includes steps ho decision on the source cell control and evaluation of ue and enb measurements taking into account certain ue specific area restrictions and. Target c rnti, target drb id uldl, target enb as security algorithm cell. A rach preamble is also included for contention free rach access. C rnti to confirm the handover, along with an uplink buffer status report to the target enb to indicate that the handover procedure is completed for the ue. The tenb checks for resource availability and, if available, reserves the resources and sends back the handover request acknowledge message including a transparent container to be sent to the ue as an rrc message to perform the handover. Aug 01, 2015 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. Lte development, conformance test, optimizationcertification course amateur level lte macrlcpdcp lte protocol stack author surya patar munda surya. Upon reception of this message the ue will remove any eps bearers for which it did not. The information includes target cell id, kgnb, crnti of the ue in the source gnb, rrm.
Lte s1 handover s1 handover lte mobile enodeb network. Pdcch dci format 1 temporary c rnti 1 the enodeb signals a downlink assignment using the temporary c rnti 1. The research topic of this thesis which is lte handover performance. The cell random network temporary identifier crnti. On intermme handover as on intramme handover, the fresh kenb is transferred to the target enb. He is a member of mobile communications and quantum informatics laboratory mcl, an associate member of the. This message includes information about the assigned radio resources. 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. Handover happens toward the other lte nodes intermme and intersgw interrat. The ue is now prepared to download the master information block. Lte rnti vs gutibasics of rnti identifier and guti in lte. When the ue has successfully accessed the target cell, the ue sends the rrc connection reconfiguration complete message c rnti to confirm the handover, along with an uplink buffer status report to the target enb to indicate that the handover procedure is completed for the ue. In the scenario described here serving gw is also unchanged. A cell radio network temporary identifier c rnti allocation method and device are disclosed.
Cell radio network temporary identifier, the crnti is a ue identifier allocated by a controlling rnc and it is unique within one cell controlled by the allocating crnc. Lte device tracking with c rnti further lte protocol exploits could potentially allow a passive adversary to locate and track devices and users. A method and system for efficient drx operation during handover in lte in which a user equipment expects handover to occur, the method having the steps of. Calculate new crc bits and mask them with the c rnti. Us8023467b2 method and system for efficient drx operation. The invention discloses a c rnti distribution method and system. Nemo outdoor qualcomm vs samsung shannon 333335355 based.
Mar 15, 2015 x2 handover the target enodeb responds back to the source enodeb with a handover request acknowledge message. If you are working in telecommunication field then you will hear this term rnti everyday. The c rnti distribution method and system are used for giving out a solution according to which c rntis are distributed to ue under the condition that the ue aggregates resources of multiple base stations. Lte rach procedure duplex telecommunications computer. A new c rnti is allocated when the ue leaves the current cell and moves to a new cell through a random access procedure. Dedication this book is dedicated to my family who has given me support to complete this book. Ep2814272a1 establishing s1 signaling connection in evolved. A new kenbis derived from the kenb and c rnti, and krrcenc, krrcint, kupencare refreshed with the help of this new kenb. Handover procedure an overview sciencedirect topics. It has to be noted that the c rnti and ue identity is unique. In particular, the detailed operation of s1ap, x2ap, rrc and nas is examined in context with a variety of key lte procedures such as network attach, bearer establishment and mobility both intra and inter lte mobility. 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. Support for this feature requires enhancement to the lte release 89 phy, mac, and rrc.
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