Key points circuit switching circuit switching is used in public telephone networks and is the basis for private networks built on leasedlines. 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. Own work manually created version of the diagram from 3gpp ts 23. 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. In other words, ultraflash csfb can provide an even shorter callsetup time than a native 23g cs call. Circuit switched fallback csfb csfb is the mechanism to move a subscriber from lte to a legacy technology to obtain circuit switched voice service. 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 circuit switched part shows significant traffic reduction if voice services are completely supported by lte voims. In the commercial worldwide web, video and audio content is increasing on web pages 1, 2, making these file sizes quite large. In such networks, the mobile phones fall back to 2g or 3g networks that support circuit switch calls.
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. Circuit switched fallback csfb mobile terminating call in. But our results suggest that in the core of the network, where high capacity is needed most, and where peak. Circuit switched fallback interworking solution function for 3gpp2 1xcs. As noted in figure 4, the 1xcs iws is an addition to legacy networks, while the mme and the evolved node. 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. But a majority part of todays traffic comes from cs based services like voice and sms. This is the modified version step 1 is gone of what you could find following the link above. Fast file transfers across optical circuitswitched networks 1. Circuitswitched network circuitswitched communication. Network architecture options and performance 3 the architecture in figure 3 shows a simplified view of the parallel lte and 2g3g networks. When exploring the detailed flow, you can examine the full contents of individual messages. Ranap iurelease random access procedure ue connects back to the 4g lte network.
A method of reducing delay in circuit switched fallback csfb in a radio access technology rat communications network. Once the connection is made the only delay is propagation time. Cs fallback function for combined lte and 3g circuit switched services. The 3gpp 3rd generation partnership project then defines the csfb when using circuit switchedbased. So 3gpp agreed to provide an intermediate solution for cs circuit swtich based services till ip based services like volte completely developed and deployed.
How to run a slideshow presentation from pdf raufs. Using csfb cs fallback ue can move to geran, utran or. Csfb allows 3g4g capable user equipment ue to fallback to the 3g network for circuit switch functions, supports sms, and voice calls. Starting from step 2 of the procedure presented below. Aug 30, 2016 csfb circuit switch fall back slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. 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.
Thus, the circuitswitched network will offer the same maximum rate as a packetswitched network. Cs fallback function for combined lte and 3g circuit. The necessity for a circuit switch fallback for the packetbased allip network, lte, which cannot support circuitswitched calls. The 3gpp 3rd generation partnership project then defines the csfb when using. May 15, 20 pdf portable document format is becoming a more professional standard for files, presentations or other important documents.
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. Pdf circuit switch fallback improvement and the smarter way. The sonetsdhwdm circuitswitched networks shown in fig. Jun 30, 2017 lte circuit switched fallback detailed flow explore the individual messages at field level. The legacy core network consists of a circuit switched and a packet switched part. Lte to 3g circuit switched fallback lteto3g circuit switched fallback.
These functions support testing without needing to switch between tester rf connectors or powerdown and up again repeatedly. 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. Cs fallback function for combined lte and 3g circuit switched. The route for the whole length of the communication session between the two communicating bodies is dedicated, exclusive, and released only when the session. 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. Qualcomm technologies circuit switched fallback to 1x voice. 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.
The sonetsdhwdm circuit switched networks shown in fig. Luckily, you know that pdfs can be displayed on almost any. 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. Configure csfb to activate in cisco asr5x00 series mme cisco. 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. In modern circuitswitched networks, electronic signals pass through several switches before a connection is established. 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. For instance, when an lte network is not available to make or. Pdf circuit switch fallback improvement and the smarter way for. Fast file transfers across optical circuitswitched networks. To deploy this method, the operator should have gsmumts deployment in the lte coverage areas, or have arrangement with other operators having such deployments. When an lte handset makes or receives voice calls, the device.
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. When an lte device is used to make or receive a voice call or sms, the device. Isr with circuit switched fallback isrwithcsfbfeaturedescription, page 1 callflows, page 2 relationshipstootherfeatures, page 4 relationshipstootherproducts, page 4. Lte to 3g circuit switched fallback lteto3gcsfbmscrole. 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. Chapter 2 circuit and packet switching stanford university. Test example ue trx calibration lte fdd test handover lte tdd test csfb wcdma test interrat handover gsm test mt8821c system.
Circuit switched fallback is needed because lte is a packetbased allip network that cannot support circuit switched calls. Circuit switched fallback csfb is one of the solutions to deliver voice service in lte network. First lte to wcdma voice call handover completed by qualcomm and ericsson feb 2012. Qualcomm, circuit switched fallback the first phase of voice evolution for mobile lte devices, qualcomm media,2012. Lte doesnt support circuit switched calls, because it is an ip based network. 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. 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. Circuit switching was developed to handle voice traffic but also digital data although inefficient with circuit switching a dedicated path is established between two. Mme selects the mscvlr for the circuit switch fallback functionality.
Solution highlights truecall leads the new generation of mobile geoanalytics platforms providing unique realtime, endtoend, multivendor, multi. 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. 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 performance of circuit switching in the internet. The model can predict only the reduced capacity requirements for these. 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. Circuit switching implies the need to first set up a dedicated, endtoend path for the connection before the information transfer takes place. And during a call, no other network traffic can use those switches. Sequence diagram generated from wireshark pcap file with. 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. 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.
Single radio solutions use csfb to switch between lte and 2g3g access modes. 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. Circuit switched fallback in evolved packet system. Pdf portable document format is becoming a more professional standard for files, presentations or other important documents. Click on the excerpt to see the pdf sequence diagram that lists all message interactions from the core network and mscvlr interfaces. This mainly affects the capacity of the msc and transport requirements. Consequently, automobile and invehicle equipment manufacturers are placing heavy emphasis on. Volte, through its superior user experience and spectrum utilization, presents the opportunity for more bread and more butter through reduced spectrum capex, increased. Benefits this feature will assure that the umtslte dualmode devices are moved to lte when there is lte coverage.
As noted in figure 4, the 1xcs iws is an addition to. Lte circuit switched fallback csfb performance 3glteinfo. Information on the current status of this and other etsi documents is available at. 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. 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. Similarly for outgoing calls, the same special service request is used to move the device to 2g3g to place the outgoing call. Background and problem statement sizes of data files used in both commercial and scientific communities can be expected to grow. While the long term evolution lte circuit switched fall back csfb can be considered as a. We have proposed a smarter way for csfb implementation, to clear all the confusions facing operators having still lte network voiceless, and hesitating. Circuit switching seeking out and establishing a physical copper path from endtoend historic definition. What is circuit switched fallback, and how does it affect. Automobile cellular communications cybersecurity penetration.
Qualcomm, circuitswitched fallback the first phase of voice evolution for mobile lte devices, qualcomm media,2012. Us9565598b2 method and system to reduce delay in circuit. Device is registered for both cs and ps services via lte. Lte is an allip technology and therefore cannot transport switched services such as voice or sms, so csfb is needed. According to the end of csfb flag, the nodeb knows that the ue is lte capable. 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. Circuit switched cs fallback in evolved packet system eps. The mobile device receives this and sends a service request back to the network. 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. Lte circuit switched fallback detailed flow explore the. 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. If you continue browsing the site, you agree to the use of cookies on this website. Location update request imsi, lai update the ue location in the 3g network 2. Packet switching o circuit switching was designed for voice o packet switching was designed for data. Aug, 2015 3rd generation partnership project 3gpp ts 23.
Location update response imsi, tmsi msc acknowledges the location update. The tracking is performed by acquiring s110 trace data of the voice calls in both the source mobile communication. Jan 18, 2012 circuitswitch fallback csfb enables circuitswitched voice and sms services to be delivered to long term evolution lte devices. References 3rd generation partnership project 3gpp technical specfications ts 23. Wo2017063700a1 intertechnology circuitswitched fallback. Mobility is thus assured also for very active devices that do not enter ura or idle mode. 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.
The rst phase of voice evolution for mobile lte devices. Cs fallback from eutran to cdma2000 enables the delivery of csdomain services by reuse of the cdma2000 infrastructure when. Nov 22, 2012 lte circuit switched fallback csfb architecture. Lte to 3g circuit switched fallback lteto3gcircuitswitchedfallback.
Qualcomm had done some performance evaluation of different cs fallback methods. Pdf circuit switch fallback improvement and the smarter. 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 information from the network. Circuitswitch fallback csfb enables circuitswitched voice and sms services to be delivered to long term evolution lte devices. File transfers across optical circuitswitched networks. 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. Csfb circuit switched fallback network, network, and.
Ultraflash csfb white paper callsetup time for ultraflash csfb as shown in figure 7, an ultraflash csfb callsetup takes only about 3. Qualcomm technologies circuitswitched fallback to 1x voice. Lte to 3g circuit switched fallback csfb lte long term. 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.
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