Lte voice, csfb, voltesrvcc xiaobo wu has over eight years of experience in telecommunications. 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. Channel allocation is done in circuitswitched mode, as with csd. Csfb is the solution to the reality of mixed networks today and throughout the transition to ubiquitous all. As operators define their implementation plans, the circuit switched fallback. The message also notifies the ue about the 3g location area that needs to be used in 3g access for the voice call. The circuit guarantees the full bandwidth of the channel and remains connected for the duration of the communication session. The only merging point is that, the 4g lte phone has to. Circuitswitch fallback csfb enables circuitswitched voice and sms services to be delivered to long term evolution lte devices. We use simple mgi1 and mgin queues to model application ows in both packetswitched and circuitswitched.
Wireless blog posts on lte circuit switched cs fallback. Mme selects the mscvlr for the circuit switch fallback functionality. Following a lowprofile launch by three in december 20, all four of the uk mobile network operators now offer 4g lte services to at least some of their. Pdf circuitswitched fallback ultraflash csfb parth. Packet switching circuit switching message switching. Our analysis consisted of automatic and manual analyses. Lte circuit switched fallback csfb performance 3glteinfo. This 1x circuit switched fallback 1xcsfb is based on 3gpp technical specification 23. Circuit switched fallback is needed because lte is a packetbased allip network that cannot support circuitswitched calls. Csfb circuit switched fallback a mechanism introduced to allow subscribers on a 4g network to make and receive voice calls. Summary introduction to wireless lte 4g architecture and key. This rich set of cs domain features and capabilities are the result. Voice over lte volte is a technology which enables voice calls over an lte network. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in tr 21.
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. As you will see in your exploration of this guide, there are many methods for. Translation find a translation for circuit switched fall back in other languages. 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. The first alternative to circuitswitched networks is the evolving technology known as voice over longterm evolution volte. Lte to 3g circuit switched fallback lteto3gcsfbmscrole. Switching, circuit switching, cell switching and explain why. Circuit switched fallback csfb cs domain services are the services that can be offered today in gsmumts networks. Initial context setup request cs fallback indicator cs fallback required, registered lai plmn, mcc, mnc, lac the mme signals to the ue that cs fall back is required. In other words, ultraflash csfb can provide an even shorter callsetup time than a native 23g cs call. Pdf performance of cs fallback from lte to umts researchgate. Once the connection is made the only delay is propagation time.
First lte to wcdma voice call handover completed by. Pdf circuit switch fallback improvement and the smarter. How voice calls affect data in operational lte networks purdue. 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. A hybrid router architecture for networksonchip noc is presented, it combines spatial division multiplexing sdm based circuit switching and packet switching in order to efficiently and separately handle both streaming and besteffort traffic generated in realtime applications. Circuit switching implies the need to first set up a dedicated, endtoend path for the connection before the information transfer takes place. 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. When the subscriber initiates a voice service, the eps network makes the subscriber fall back to the target cs network to. In january 1878, the first telephone switch went into operation in new haven connecticut. Lte to 3g circuit switched fallback lteto3gcircuitswitchedfallback. Circuit switched fallback csfb addresses the requirements of the first phase of the evolution of mobile voice services, which began on a commercial scale in 2011.
Pdf circuit switched fallback csfb is the most commonly used method to support voice services over long term evolution lte networks. Circuit switched fallback optimization lte optimization. The tcpip guide circuit switching and packet switching. Here, we explore the performance of a network that uses tcp switching, with particular emphasis on the response time experienced by users. What is circuit switched fallback, and how does it affect. Messagepacket switching vs circuit switching router router header mesgpack router. 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 circuitswitched fallback to 1x voice. Lte is an allip technology and therefore cannot transport switched services such as voice or sms, so csfb is needed. It sends voice calls over ipbased lte networks and harnesses data capabilities of lte with traditional voice services on to the same lte network. Lte csfb architecture from lte eutran to gsm geran and umts utran. Cs fallback function for combined lte and 3g circuit.
Circuit switching and packet switching networks page 1 of 3 in my grand overview of networking, i describe networks as devices that are connected together using special hardware and software, to allow them to exchange information. Circuit switching is a method of implementing a telecommunications network in which two network nodes establish a dedicated communications channel through the network before the nodes may communicate. When exploring the detailed flow, you can examine the full contents of individual messages. 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. The main benefits of single radio solutions such as 1xcsfb are. Key points circuit switching circuit switching is used in public telephone networks and is the basis for private networks built on leasedlines. Network architecture options and performance 3 the architecture in figure 3 shows a simplified view of the parallel lte and 2g3g networks. Circuit switched fallback csfb mobile terminating call. The first phase of voice evolution for mobile lte devices. The rst phase of voice evolution for mobile lte devices. As noted in figure 4, the 1xcs iws is an addition to.
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. Lte doesnt support circuit switched calls, because it is an ip based network. For the purposes of the present document, the abbreviations given in tr 21. Generate attractive communication services by merging mobile voice with video, the web and social networking. Cs fallback function for combined lte and 3g circuit switched.
It will not completely substitute the manual configuration and optimization. Using csfb cs fallback ue can move to geran, utran or cdma2000 systems more. In order to provide a cs service in a lte network, circuit switched fallback csfb technology maybe employed in the lte network 36. Location update request imsi, lai update the ue location in the 3g network 2.
Voice over lte market size volte industry report, 2025. Chapter 2 circuit and packet switching stanford university. Circuit switch fallback improvement and the smarter way. The necessity for a circuit switch fallback for the packetbased allip network, lte, which cannot support circuitswitched calls. This is the modified version step 1 is gone of what you could find following the link above. In essence, when a mobile originated terminated call needs to take place, the subscriber will leave the 4g network and fall back to the 2g3g. Pdf circuit switch fallback improvement and the smarter way for. Initially making its way to commercial markets in 2009, volte allows voice calls to travel over lte networks. But a majority part of todays traffic comes from cs based services like voice and sms. Xiaobo wu, wireless mbb research department, wireless network research department, huawei area of expertise. High speed circuit switched data hscsd, is an enhancement to circuit switched data csd, the original data transmission mechanism of the gsm mobile phone system, four to six times faster than gsm, with data rates up to 57. 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.
The circuit functions as if the nodes were physically connected. Because these complex procedures are merged, optimizing csfb. Lte circuit switched fallback detailed flow explore the individual messages at field level. For instance, when an lte network is not available to make or receive either a. When an lte device is used to make or receive a voice call or sms, the device falls back to the 3g. Starting from step 2 of the procedure presented below.
Switching technology had advanced drastically over the intervening decades, yet the basic function had remained the same. 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. The most important word in that sentence is the final one. Maps lte sgs emulator test lte sms and cs fall back over. Technical specification ts initial planned release. Qualcomm, circuitswitched fallback the first phase of voice evolution for mobile lte devices, qualcomm media,2012. While voice calls still depend on aging 3g networks, lte has continued to evolve and merge with voice, allowing. 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. In such networks, the mobile phones fall back to 2g or 3g networks that support circuit switch calls. The technology enables both voice and data to merge thereby resulting in better efficiency as well as quality. Circuit switching and packet switching are two different ways of sharing links in a communication network. 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. Lte networks in the future phases of lte voice evolution.
Circuit switching was developed to handle voice traffic but also digital data although inefficient with circuit switching a dedicated path is established between two. Cs fallback, a func tion for combining epc supporting lte and cs services like. Circuit switched fallback csfb is one of the solutions to deliver voice service in lte network. Circuit switched cs fallback in evolved packet system eps. Like circuit switched telephony networks, 2g3g mobile networks. Csfb 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. Cs fallback from eutran to cdma2000 enables the delivery of csdomain services by reuse of the cdma2000 infrastructure when. Csfb circuit switched fallback network, network, and. Location update response imsi, tmsi msc acknowledges the location update. The performance of circuit switching in the internet.
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. Comparative analysis for mpeg decoder was implemented using circuit switched and packet switched network wherein the circuit switched network is better in its performance in terms of power, delay. The 3gpp 3rd generation partnership project then defines the csfb when using circuit switchedbased services to deliver voice or 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. Switches in a circuitswitched network process connection establishment and teardown messages, whereas switches in a. Circuitswitched fallback ultraflash csfb white paper huawei technologies co.