A set of logical channel types is defined for different kinds of data transfer services as offered by mac. Developed and maintained by the 3gpp 3rd generation partnership project, umts is a component of the international telecommunications union imt2000 standard set and compares with the cdma2000 standard set for networks based on the competing cdmaone. Umts terrestrial radio access network utran umts terrestrial radio access utra. Selection of the transport format based on current needs 3. Consists of many logical network elements similar to the 2g systems. Gsm uses a variety of channels in which the data is carried. Universal mobile telecommunication system umts is a third generation mobile. Mac channels logical channels exist at the top of the mac represent data transfer services offered by the mac they are defined by what type of information they carry types of logical channels control channels for control plane data traffic channels for user plane data transport channels exist at the bottom of the mac. Comprehesive coverage of umts 3g news, licensing, business developments, 3g wcdma telecommunication technology, multi media mobile phones and future communications. Each logical channel type is defined by what type of information is transferred. Simply put, this means in direct radio to radio communication the same frequency may be used for reception and. This is very specifically an issue with regards to transient memory ram usage. Aug 25, 2009 logical channels define what type of information is being transferred and transport channel defines how the information is being transferred.
May 20, 2015 all these kinds of messages are classified in logical channels. This book provides a comprehensive description of radio access networks for umts. A logical file is a view or representation of one or more physical files. The umts channels are communication channels used by third generation 3g wireless universal mobile telecommunications system umts networks. Physical and logical channels gsm uses a mix of frequency division multiple access fdma and time division multiple access tdma. The umts world is an 3g mobile system news and information provider.
Aug 03, 2017 mapping of these channels is shown in below pictures. In gsm, these channels are separated into physical channels and logical channels. The channels logical, transport and physical mapping information through the channels the umts terrestrial radio access network utran requirements of the utran utran nodes and their functionality node b controlling radio network controller serving radio network controller drift radio network controller general interface. These channels define the datatransfer services offered by the mac layer. Universal mobile telecommunications system umts is a thirdgeneration cellular network that enables highspeed wireless internet access. Data and signalling messages are carried on logical channels between the rlc and mac layers. Enhanced uplink dedicated channel edch high speed uplink. Umts logical channels and transport channels 3glteinfo. A physical radio channel is a radio frequency or pair of frequencies that is allocated by the regulatory body to an agency for communication.
Jan 11, 20 lte logical channels structure and mapping between logical channels and transport channels. Channels in umts mapping between logical, transport, and physical channels logical channels broadcast control. This paper investigates the performance of transmission control protocol tcp over umts utilizing a common and four dedicated transport channels with bit rates up to 2 mbs. Gprs general packet radio service a packet oriented data service for ip and x. Since channels and links are not similar things to differentiate or compare, im just going to define and elaborate bit on each of them. Gsm interfaces u m radio interface between ms and bts each physical channel supports a number of logical channels a bis between bts and bsc vender specific primary functions. The downlink direction from network to terminal is covered first. Dpcch carries the transport format combinations needed by the receiver to be able. A logical file is a database file that describes how data records contained in one or more physical files are presented to a. Interface in umts radio network iub, iur, iu cs and iu ps. As they tranverse between layers they map to other layer frames. The need for 3rd generation systems modern mobile networks an overview services provided by gsmgprs edgewap future perceived service requirements the requirement for the next generation of networks the itu requirement for imt 2000 etsi, 3gpp and umts standardisation channels through the utran.
Umts stands for universal mobile telecommunications system. Gsm channels university of engineering and technology. This should serve as a basic explanation towards the gsm logical channels. Coherence bandwidth limits the maximum data rate of the channel. Logical files that contain more than one format are referred to as multiformat logical files. Performance of tcp over umts common and dedicated channels. Based on, as mentioned earlier, whether they carry gsm traffic ie, speech or data or gsm. Developed and maintained by the 3gpp 3rd generation partnership project, umts is a component of the international telecommunications union imt2000 standard set and compares with the cdma2000 standard set for networks based on the competing. Physical file contains the actual data that is stored in iseries system. Multiple access protocols for mobile communications. What is the difference between a physical file and logical. They are used to transport speech, user data, high layer signally, cell specific information to name a few. File systems 3 disks and the os disks are messy physical devices.
Normally you see only cards with 2 logical channels. Mapping of logical channels on transport channels 2. In this tutorial different types of logical channels and transport channels and their mappings are described. Utran umts terrestrial radio access network handles all radio.
File transfer protocol ftp, hypertext transfer protocol. For gsm1800 frequency spectrum of 75 mhz bandwidth is. Theses are actual physical rf channels 79 frequenc. How to demap logical channels from say, hsdschhigh speed downlink shared channel in umts mac. The os may provide different levels of disk access to. I suggest to you links and attached files in subject.
Different bursts are mapped to these channels uniquely as per gsm technical specification 05. As shown in the figure there are two main types of channels in the gsm. Wcdma osi model radio resource control rrc logical channels rlc rlc rlc what is transmitted medium access control mac transport channels how it is transmitted physical layer physical channels code,frequency,etc. Lte logical channels structure and mapping between logical channels and transport channels. The following picture depicts the logical channel hierarchy. Air interface in the umts system, physical and logical channels of umts systems. Logical channels in gsm are defined by the type of information that is carried over them. What is the difference between physical channel and. There are broadly two categories of logical channels available. Mac provides the control and traffic channels listed in table 4. The job of the os is to hide this mess from higher level software lowlevel device control initiate a disk read, etc. Apr 26, 2016 physical file contains the actual data that is stored in iseries system. Logical channels can be broadly divided into two types. Depending on the quantity of information to transmit and on their consistency, several logical channels may be mapped onto one physical channel, in order to use its successive time slots as much as possible optimization of the resources number by maximizing the occupancy duration of each.
Multiple access protocols for mobile communications gprs, umts and beyond alex brand swisscom mobile, switzerland. The mac model maps logical channels on to transport channels. Umts channels logical,transport,physical umts channels. Dedicated logical channels are allocated to a speci. Records in database files either a field level description or record level description. Selection of transport format for each transport channel.
Mapping of these channels is shown in below pictures. An uplink packet is then described, highlighting any differences. Furthermore, we depict the protocol details required. Logical file dds, however, contains only the field names needed for the subset. Communication with higher layers, logical channels is used. The create logical file crtlf command creates a logical file from the information specified on this command and from the data description specifications dds contained in a source file. Permission is granted to copy, distribute andor modify this document under the terms of the gnu free documentation license, version 1.
As shown in the figure, there are three types of umts channels viz. The universal mobile telecommunications system umts is a third generation mobile cellular system for networks based on the gsm standard. Agilent application note compare with transport channels in umts mapping between logical, transport, and physical channels logical channels broadcast control channel multicast control channel paging control channel common control channel dedicated control channel dedicated traf. For example, the dds necessary to create the logical file listed in table 11. Starting from the highlevel network architecture, the first sections describe the flow of data between the. Logical channels tells what kind of information is transferred. 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 secretariat. Logical control channels carry signaling messages in the control plane.
Information on the current status of this and other etsi documents is available at. Mapping between logical channels and transport channels. The main content is based upon the release 6 version of the 3gpp specifications. Introduction to umts technology 1 principles of wcdma 1 spread spectrum 1 protocols and channels 2 protocol architecture 2 layer 1 l1 or physical layer 2 layer 2 l2 or data link layer 2 layer 3 l3 or network layer 3 transport channels 4 downlink common and dedicated 4 uplink common and dedicated 4 logical channels 5 control channels 7. Long term evolution protocol overview nxp semiconductors. Each transport channel which is accompanied by the transport format indicator tfi. What is the difference between a physical file and logical file. Umts networks andreas mitschelethiel, jens mueckenheim nov. We then discuss logical channels or transport channels describing the type of data that are transmitted and physical channels timefrequencycode resources. For example speech is sent on the logical channel traffic channel which during the transmission is allocated a certain physical channel, say ts 6 on carrier 0. How to demap logical channels from say, hsdschhigh speed. How channel mapping in wcdma broadcast control channel dtch dedicated traffic channel rach random access channel fach forward access channel dsch downlink shared channel dcch dedicated control channel cpch common packet channel ctch common traffic channel dch dedicated transport channel pcch paging control channel pch paging channel. A copy of the license is included in the section entitled gnu free documentation license. Umts networks andreas mitschelethiel, jens muckenheim nov.
Logical channels reside between radio link control rlc and medium access control mac layer. Logical channels define what type of information is transferred. Transport format combination identifier tfci, feedback information fbi and transmission power. This tutorial on umts covers umts logical channels, transport channels and physical channels. A logical channel will carry information of a specific type and a number of these channels may be combined before being mapped onto the same physical channel. Transport channel, logical channel and macd flow numbering. A logical file is a database file that describes how data records contained in one or more physical files are presented to a program. Third edition edited by harri holma and antti toskala both of nokia, finland. Rlc channels logical channels split 6 transport channels split 73. Jan 14, 2011 however, please note that the description made above of the basic channels at the bottom of the tree ie, fundamental logical channels like tchf, facch, rach etc, remains the same. Logical channels define what type of information is being transferred and transport channel defines how the information is being transferred logical channels. Changes since the release 99 version are described while some of the new features from the release 7 version are introduced. The physical channels are determined by the timeslot, whereas the logical channels are determined by the information carried within the physical channel.
Like any form of wireless data link, the data needs to be managed to enable the system to handle it efficiently and effectively. The contents of the present document are subject to continuing work within the. One topic that often causes confusion in digital radio networks is the difference between physical and logical channels. Logical files are created with dds source in the same manner as physical files. Comprehensive coverage of umts 3g news, licensing, business developments, 3g wcdma telecommunication technology, multi media mobile phones and future communications. Logical channels reside between rlc sublayer and mac sublayer which are layer 2 protocols in lte protocol stack. Fdma parts involves the division by frequency of the 25 mhz bandwidth in to 124 carrier frequencies also called arfcn spaced 200 khz for gsm900. All these kinds of messages are classified in logical channels. They contain a description of records found in one or more physical files.
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