Svlte, circuitswitched fallback csfb, and voice over longgain antenna volga all vying for supremacy, but ipmultimedia subsystembased imsbased volte has now emerged as the long. Radio voice call continuity srvcc handover challenges, and circuitswitched fallback csfb and voice call continuity vcc issues to ensure high quality and consistent voice services. This function is only available if lte coverage is overlapped by either geran gsm edge radio access network coverage or utran umts terrestrial radio access network coverage as shown in figure 1. The legacy core network consists of a circuit switched and a packet switched part. What is circuit switched fallback, and how does it affect. File transfers across optical circuitswitched networks. We have proposed a smarter way for csfb implementation, to clear all the confusions facing operators having still lte network voiceless, and hesitating. Mme selects the mscvlr for the circuit switch fallback functionality. Background and problem statement sizes of data files used in both commercial and scientific communities can be expected to grow.
Lte to 3g circuit switched fallback lteto3g circuit switched fallback. Ultraflash csfb white paper callsetup time for ultraflash csfb as shown in figure 7, an ultraflash csfb callsetup takes only about 3. A method of reducing delay in circuit switched fallback csfb in a radio access technology rat communications network. In the commercial worldwide web, video and audio content is increasing on web pages 1, 2, making these file sizes quite large. Isr with circuit switched fallback isrwithcsfbfeaturedescription, page 1 callflows, page 2 relationshipstootherfeatures, page 4 relationshipstootherproducts, page 4. And during a call, no other network traffic can use those switches. Wo2017063700a1 intertechnology circuitswitched fallback. If you continue browsing the site, you agree to the use of cookies on this website.
Chapter 2 circuit and packet switching stanford university. Qualcomm had done some performance evaluation of different cs fallback methods. Nevertheless, voice is one of the most important services in mobile communications, and it is important that voice services can still be provided in some way even during the time that the lte platform is providing highspeed data communications services without. May 15, 20 pdf portable document format is becoming a more professional standard for files, presentations or other important documents. Mobility is thus assured also for very active devices that do not enter ura or idle mode. Circuit switched fallback operates when a mobile device is functioning in lte mode and fields an incoming call to the lte network by paging the device.
The present invention relates to the tracking of a transfer of voice calls from a source mobile communication network 10 to a target mobile communication network 20 when a circuitswitched fallback, csfb, procedure is performed for the voice calls. These functions support testing without needing to switch between tester rf connectors or powerdown and up again repeatedly. Thus, the circuitswitched network will offer the same maximum rate as a packetswitched network. In other words, ultraflash csfb can provide an even shorter callsetup time than a native 23g cs call. Cs fallback function for combined lte and 3g circuit switched. First lte to wcdma voice call handover completed by qualcomm and ericsson feb 2012. Location update request imsi, lai update the ue location in the 3g network 2. Network architecture options and performance 3 the architecture in figure 3 shows a simplified view of the parallel lte and 2g3g networks. When an lte device is used to make or receive a voice call or sms, the device. The sonetsdhwdm circuit switched networks shown in fig. Circuit switched fallback csfb mobile terminating call in. Further after completing the above procedure is as in the active mode described previously in circuit switched fallback csfb mobile terminating call in active mode, no ps ho.
According to the end of csfb flag, the nodeb knows that the ue is lte capable. Key points circuit switching circuit switching is used in public telephone networks and is the basis for private networks built on leasedlines. Circuit switched fallback is needed because lte is a packetbased allip network that cannot support circuit switched calls. Aug 30, 2016 csfb circuit switch fall back slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. The necessity for a circuit switch fallback for the packetbased allip network, lte, which cannot support circuitswitched calls.
Pdf portable document format is becoming a more professional standard for files, presentations or other important documents. How to run a slideshow presentation from pdf raufs. The rst phase of voice evolution for mobile lte devices. So 3gpp agreed to provide an intermediate solution for cs circuit swtich based services till ip based services like volte completely developed and deployed. Cs fallback function for combined lte and 3g circuit switched services. Isr with circuit switched fallback isrwithcsfbfeaturedescription, page 1 callflows, page 2 relationshipstootherfeatures, page 4 relationshipstootherproducts, page 4 howitworks, page 5 isrcsfbprocedures, page 6 standardscompliance, page 9. Luckily, you know that pdfs can be displayed on almost any. Lte doesnt support circuit switched calls, because it is an ip based network. When a ue is camped on the lte network, it needs to fallback to the cs domain when a voice call is initiated or received. Ranap iurelease random access procedure ue connects back to the 4g lte network. Hijack voice calls and sms by abusing cs circuit switched fallback as selfdriving vehicle technologies progress, these cybersecurity problems are becoming increasingly important in the automobile business world. Circuitswitched network circuitswitched communication.
Click on the excerpt to see the pdf sequence diagram that lists all message interactions from the core network and mscvlr interfaces. Packet switched lte is the current gold standard for mobile data it stands for long term evolution, although you may know it better as 4g. Qualcomm technologies circuitswitched fallback to 1x voice. The model can predict only the reduced capacity requirements for these. Csfb allows 3g4g capable user equipment ue to fallback to the 3g network for circuit switch functions, supports sms, and voice calls.
Volte, through its superior user experience and spectrum utilization, presents the opportunity for more bread and more butter through reduced spectrum capex, increased. Solution highlights truecall leads the new generation of mobile geoanalytics platforms providing unique realtime, endtoend, multivendor, multi. When the subscriber initiates a voice service, the eps network makes the subscriber fall back to the target cs network to. Similarly for outgoing calls, the same special service request is used to move the device to 2g3g to place the outgoing call. The circuit switched part shows significant traffic reduction if voice services are completely supported by lte voims. The sonetsdhwdm circuitswitched networks shown in fig. Cs fallback function for combined lte and 3g circuit. Dec 21, 2016 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. Circuit switched fallback csfb csfb is the mechanism to move a subscriber from lte to a legacy technology to obtain circuit switched voice service. Qualcomm, circuitswitched fallback the first phase of voice evolution for mobile lte devices, qualcomm media,2012. Circuit switched fallback csfb is the most commonly used method to support voice services over long term evolution lte networks today, as the deployment of ip multimedia subsystem ims is still in its infancy. But a majority part of todays traffic comes from cs based services like voice and sms. Circuit switched fallback csfb is a technology whereby voice and sms services are delivered to lte devices through the use of gsm or another circuitswitched network circuit switched fallback is needed because lte is a packetbased allip network that cannot support circuitswitched calls.
Device is registered for both cs and ps services via lte. Location update response imsi, tmsi msc acknowledges the location update. Automobile cellular communications cybersecurity penetration. Circuit switched cs fallback in evolved packet system eps. Own work manually created version of the diagram from 3gpp ts 23. But our results suggest that in the core of the network, where high capacity is needed most, and where peak.
Information on the current status of this and other etsi documents is available at. Pdf circuit switch fallback improvement and the smarter. As noted in figure 4, the 1xcs iws is an addition to. Lte is an allip technology and therefore cannot transport switched services such as voice or sms, so csfb is needed. Circuit switched fallback csfb csfb no voip pure cs voice services registration ue register with msc via mme calls originates mo calls via 2g 3g cs network pages ue via mmeenb for mt calls, calls are setup via 2g 3g cs network bscrnc msc nb sgs registration calls. Packet switching o circuit switching was designed for voice o packet switching was designed for data.
Jan 18, 2012 circuitswitch fallback csfb enables circuitswitched voice and sms services to be delivered to long term evolution lte devices. Cs fallback from eutran to cdma2000 enables the delivery of csdomain services by reuse of the cdma2000 infrastructure when. The tracking is performed by acquiring s110 trace data of the voice calls in both the source mobile communication. Circuitswitched fallback operates when a mobile device is functioning in lte mode and fields an incoming call to the lte network by paging the device. Csfb network architecture ue lte uu e utran mme s1 mme utran geran um uu msc server iu cs a sgs ue lte uu e utran mme s1 mme utran geran um uu msc server iu cs a sgs 3. Circuit switching implies the need to first set up a dedicated, endtoend path for the connection before the information transfer takes place.
Circuit switching seeking out and establishing a physical copper path from endtoend historic definition. Single radio solutions use csfb to switch between lte and 2g3g access modes. Thus, the circuit switched network will offer the same maximum rate as a packet switched network. Jan, 2017 circuit switched fallback csfb is the most commonly used method to support voice services over long term evolution lte networks today, as the deployment of slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
When an lte handset makes or receives voice calls, the device. Lte circuit switched fallback detailed flow explore the. Lte circuit switched fallback csfb performance 3glteinfo. Using csfb cs fallback ue can move to geran, utran or. References 3rd generation partnership project 3gpp technical specfications ts 23. Test example ue trx calibration lte fdd test handover lte tdd test csfb wcdma test interrat handover gsm test mt8821c system. In modern circuitswitched networks, electronic signals pass through several switches before a connection is established. This mainly affects the capacity of the msc and transport requirements. Circuit switched fallback csfb mobile terminating call. Radio voice call continuity srvcc handover challenges, and circuit switched fallback csfb and voice call continuity vcc issues to ensure high quality and consistent voice services. Circuit switched fallback in evolved packet system. Sequence diagram generated from wireshark pcap file with.
The route for the whole length of the communication session between the two communicating bodies is dedicated, exclusive, and released only when the session. Us9565598b2 method and system to reduce delay in circuit. Circuit switched fallback csfb is a technology whereby voice and sms services are delivered to lte devices through the use of gsm global system for mobile communications or another circuit switched network. Once the connection is made the only delay is propagation time. Circuit switched fallback csfb is a technology whereby voice and sms services are delivered to lte devices through the use of gsm global system for mobile communications or another circuitswitched network. We conclude that because of high bandwidth longlived ows, it does not make sense to use circuit switching in shared access or local area networks. While the long term evolution lte circuit switched fall back csfb can be considered as a. Benefits this feature will assure that the umtslte dualmode devices are moved to lte when there is lte coverage. Circuit switched fallback csfb, with the help of a global system for mobile communication gsm or another circuitswitched network, delivers voice and sms services to lte devices. Csfb circuit switched fallback network, network, and. Lte to 3g circuit switched fallback lteto3gcsfbmscrole.
Starting from step 2 of the procedure presented below. Jun 11, 2015 csfb allows 3g4g capable user equipment ue to fallback to the 3g network for circuit switch functions, supports sms, and voice calls. Circuit switching was developed to handle voice traffic but also digital data although inefficient with circuit switching a dedicated path is established between two. Pdf circuit switch fallback improvement and the smarter way. Truecall leads the new generation of mobile geoanalytics platforms providing unique realtime, endtoend, multivendor, multi. 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 lte doesnt support circuit switched calls, because it is an ip based network. The mobile device receives this and sends a service request back to the network. Circuit switched fallback csfb is one of the solutions to deliver voice service in lte network.
Nov 22, 2012 lte circuit switched fallback csfb architecture. Consequently, automobile and invehicle equipment manufacturers are placing heavy emphasis on. Sep 24, 20 further after completing the above procedure is as in the active mode described previously in circuit switched fallback csfb mobile terminating call in active mode, no ps ho. To deploy this method, the operator should have gsmumts deployment in the lte coverage areas, or have arrangement with other operators having such deployments. As noted in figure 4, the 1xcs iws is an addition to legacy networks, while the mme and the evolved node. This is the modified version step 1 is gone of what you could find following the link above. Qualcomm, circuit switched fallback the first phase of voice evolution for mobile lte devices, qualcomm media,2012. Lte to 3g circuit switched fallback csfb lte long term. When an lte device is used to make or receive a voice call or sms, the device falls back to the 3g or 2g network to complete the call or to deliver the sms text message. Fast file transfers across optical circuitswitched networks 1. The performance of circuit switching in the internet. When exploring the detailed flow, you can examine the full contents of individual messages. The method includes initiating, by a terminal, a combined attach procedure by sending an attach request message to the rat communications network, receiving, by the terminal, an attach accept message along with location area identification lai. In such networks, the mobile phones fall back to 2g or 3g networks that support circuit switch calls.
Configure csfb to activate in cisco asr5x00 series mme cisco. It also supports fast return to lte for devices that has done a circuit switched fallback from lte to wcdma when the cs call is finished. The present invention relates to the tracking of a transfer of voice calls from a source mobile communication network 10 to a target mobile communication network 20 when a circuit switched fallback, csfb, procedure is performed for the voice calls. Fast file transfers across optical circuitswitched networks.
The 3gpp 3rd generation partnership project then defines the csfb when using. Qualcomm technologies circuit switched fallback to 1x voice. Pdf circuit switch fallback improvement and the smarter way for. What if you have to run a slideshow at some trade show booth, you know that slideshow will be displayed on an hdtv connected with windows laptop.
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