On downlink, the mac in the ue interprets the transport format. Radioengineering april 2018, volume 27, number 1 doi. Same radio interface schemes for both uplink and downlink ofdm and scfdma 2. Draft nistir 8071, lte architecture overview and security analysis. Other layers above tnl are not related with the air interface. Long term evolution protocol overview nxp semiconductors. Lte a meets and exceeds all requirements for 4g as specified in imtadvanced. Lte air interface is 3gpps long term evolution lte plan for current umtshspa based 3gpp networks. Lte a has frequency reuse factor of 1 since spectrum is expensive, uses highorder mimo. This nas layer terminates at mme and enb shall silently pass the nas messages to mme. Pdf estimation of the feasibility of underlay inband. Lets have a close look at all the layers available in eutran protocol stack which we have seen in previous chapter. Apart from the non access stratum nas protocols, all radio interface protocols terminate in the enodeb on the network side.
Llttee rraaddiioo pprroottooccooll aarrcchhiitteeccttuurree the radio protocol architecture for lte can be separated into control plane architecture and user plane architecture as shown below. Implementing immediate forwarding for 4g in a network. This will reach the practical limits in data rates and capacity for the existing 3g networks based on 5 mhz wcdma technology. Interfaces and their protocol stacks lte and beyond tech. Long term evolution lte, based on the 3gpp standards, is the latest. In lte air interface the physical and data link layers, also referred. The scheduling of radio resources at the mac layer uses algorithms. I will assume you dont, so here is the rather simplified answer with a few shortcuts and omissions. Air interface protocol architecture layer 1, 2 and 3 protocols mapping between logical, transport and physical channels. Introduction in the current universal mobile telecommunications system umtshsxpa specifications, systems are capable of supporting high speed packet access for both downlink up to 14 mbps and uplink up to 5. Function of control plane protocol stacks in lte teletopix. A survey of multimedia streaming in lte cellular networks. The chapter then describes how orthogonal frequency division multiple access ofdma and scfdma air interfaces are organized as a function of time and. Requirements of lte peak data rate up to 200 active users in a cell 5 megahertz less than 5 millisecond userplane latency 1.
Takes care of the link adaptation amc, power control, cell search. Lte uses several different types of logical, transport and physical channel, which are distinguished by the kind of information they carry and by the way in which the information is processed. Explain the x2s1 interface, x2aps1ap and gtp c protocols. Kawser is the author of lte air interface protocols 0. Overview of lte and lte advanced new features 151 7. For these reasons, lte is now being utilized by most major service providers. Lte a can aggregate up to 5 carriers to make up to 100 mhz 4. A parents devote the college quest in the last health topics for persuasive speech months. Fddlte air interface protocol telecom knowledge and. Radioengineering april 2017, volume 26, number 1 doi. The framework for the lte advanced air interface technology is mostly determined by the use of wider bandwidths, potentially even up to 100 mhz, noncontiguous spectrum deployments, also.
Ltes air radio interface is based on ofdmascfdma technology. Pdf coverage and capacity analysis of lte radio network. Kawser, lte air interface protocols, artech house, 2011. Pdcp maps the upperlayer protocol characteristics to the lowerlayer air interface protocol characteristics and thus enables the lte protocol to bear ip packets between ue and enode b through transparent transmission provides for the upper layer. Interfaces are allowing mme, sgw and pgw cooperating with other network elements e. A similar closedsource development commercialized by amarisoft lte 100 which targets several usrp platforms provides enb and corenetwork functionality on standard linuxbased pcs 6.
Jan 08, 2012 interfaces and their protocol stacks after familiarising with main network elements, time has come to better know interfaces between those elements. The main requirements for the new access network are high spectral efficiency, high peak data rates, short round trip time as well as flexibility in frequency and bandwidth. It follows a virtualized architecture with adaptive split of functionalities into those running on physical and virtual resources as depicted in figure 1. Architecture of the lte air interface an introduction to. Physical layer carries all information from the mac transport channels over the air interface. This paper provides an introduction to how the lte protocol stack operates. The processing in the access strata as of the protocol stack. Lte sae introduction release 7 of 3gpp includes study items to introduce mimo and 64qam as transmission technologies to increase data rate of the air interface, and ims phase 2 introduces all ip network capability. Lte interfaces and protocols telecommunications blog. The access to these services is through the use of a transport channel via the mac sublayer. Lte air interface lte is 3gpps long term evolution lte. The physical layer is expected to perform the following functions in order to provide the data transport service.
Lte tutorial tutorial on lte basics rf wireless world. Hybrid arq based on rateless coding for utran lte wireless. The technical level of the answer depends on whether you have an understanding of wireless communications and electrical engineering. Function of user plane protocol stacks in lte teletopix. This course will cover the major aspects of the lte air interface in a manner that both technical and nontechnical people will be able to fully appreciate. 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. This course is provides indepth understanding of lte air interface known as eutra.
Function of user plane protocol stacks in lte the user plane includes the data streams and the data bearers for the data streams. At user plane side, the application creates data packets that are processed by protocols such as. Lte long term evolution or the eutran evolved universal terrestrial access network, introduced in 3gpp r8, is the access part of the evolved packet system eps. Control protocol tcp protocol, one of the most used protocols in digital network. Understanding lte air interface and eutran ltes physical. Ofdma types ofdm versus ofdma ofdma physical layer lte channels. Lte air interface course description with the introduction of lte came the development of a new radio technology based on ofdma scfdma. The enb is connected to the epc via the s1 interface and to the en gnb.
Lte air interface free download as powerpoint presentation. The new physical layer is key to the level of performance that lte must deliver and much flexibility has been incorporated to cope with varying allocations of spectrum, as well as the workbook in both printed and searchable electronic formats, attendees receive a specially produced lte air interface acronym list. Assessment of lte 800 mhz base station interference into dtt receivers era technology for ofcom, report 20110351. Lte air interface protocols request pdf researchgate. Protocol states and mobility one of the main lte advantages is minimizing number of states transitions that led to huge saving in processor load.
Pdf on sep 14, 2019, mohammad kawser and others published estimation of the feasibility of underlay inband devicetodevice communication based on radio conditions in lte find, read and cite. The radio protocol architecture for lte can be separated into control plane architecture and user plane architecture as shown below at user plane side, the application creates data packets that are processed by protocols such as tcp, udp and ip, while in the control plane, the radio resource control rrc protocol writes the signalling messages that are exchanged between the base station and. Commonalities and difference in tdd and fdd tdd and fdd modes commonalities tdd and fdd modes differences regarding the air interface 1. As a result, going on with lte radio network planning perspective is a. The protocols used in the air interface, from the viewpoint of the mobile. This paper focuses on protocols specified by ran2, a. How does the lte air interface work including uplink and. Gsmonly mobile stations mss will be connected to the network via the gsm air radio interface um. The lte air interface physical layer offers data transport services to higher layers. The channels in lte system are mainly categorized into logical, transport and physical channels based on their functions. Request pdf on jan 1, 2011, mohammad kawser and others published lte air interface protocols find, read and cite all the research you need on researchgate. The course starts with basic structure of lte air interface. Request pdf on jan 1, 2011, mohammad kawser and others published lte air interface protocols find, read and cite all the research you need on. In this tutorial you can learn the following topics.
Interface is the only fully x86based sdr solution in opensource, providing both ue, enb, and corenetwork functionality. The air interface involves both the physical and data link layers layer 1 and 2 of the osi model for a connection. 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. Lteuu interface air interface of eutran based on ofdma in downlink and sc fdma in uplink fdd and tdd dupl ex methods scalablebandwid th1. Overview of lte radio interface and radio network architecture for high speed, high capacity and low latency. The data streams are characterized by one or more frame protocols specified for that interface. Request pdf hybrid arq based on rateless coding for utran lte wireless systems in this work an incremental redundancy hybrid automatic repeat request harq scheme, based on rateless coding. Rrc is the protocol that is used for communication between ue and enb. Long term evolution lte is the next step forward in cellular 3g services. Lte uses several different types of logical, transport.
With the introduction of lte came the development of a new radio technology based on ofdma scfdma. The air interface, or access mode, is the communication link between the two stations in mobile or wireless communication. Utran interface between rnc and the packetswitched domain of the cn iu ps is used for ps data and the utran interface between rnc and the circuitswitched domain of the cn iucs is used for cs data. The entire lte system is specified by a large number of 3gpp working groups which oversee everything from the air interface to the protocol stack and the infrastructure network. A significant underlying feature of lte advanced will be the flexible spectrum usage.
Explain the lte sae quality of service and security. Aug 11, 2009 utran interfaces are the most important point to start learning about the whole system. Umts interfaces protocols on different interfaces standard numbers and links to the different standards. Below is a more ellaborated diagram of eutran protocol stack. Improvement in drx power saving for nonrealtime traffic in lte. Next, the interfaces between the eps entities and the protocol stack across the interfaces are described. Ofdma is used from network to ue air interface and scfdma is used from ue to network air interface.
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