Transcoder and adaptation unit trau following is the diagram of gsm netwrok along with added elements. Overview of the gsm system and protocol architecture. The bss communicates with the network service switching nss center across the a interface. The present document specifies the stage 2 description of the outofband transcoder control for speech services. In the gsm network, the base station subsystem bss is the part of the network taking care of radio resources, that is, radio channel allocation and quality of the radio connection. Gsm adjunct systems gsm standards define that certain adjunct or secondary systems work with gsm technology. Tail allzero bits to indicate the start and the end of the burst. Aimed at service providers and large enterprises, audiocodes mt offloads media transcoding from audiocodes sbcs handling large call volumes. Transcoder and rate adaptation unit, or trau, performs transcoding function for speech channels and ra rate adaptation for data channels in the gsm network.
The bss carries out transcoding of speech channels, allocation of radio channels to mobile phones, paging, transmission and reception over the air interface and many. Dcs 1900 is considered the gsm standard for north america and is called north american gsm. Transcoders are used for a direct analogtoanalog or digitaltodigital conversation of one encoding to another. Gsm is a circuitswitched system that divides each 200 khz channel into eight 25 khz timeslots. The gsm service area is the entire gggpeographical area in which a subscriber. Pdf a study of cell site planning of gsm system researchgate. History of cellular mobile radio and gsmglobal systems for mobile l early 1980s there was analog. The gateway msc or gmsc the purpose of which is to query the hlr and determine the location of the subscriber. Mobile radio interface layer 3 specification core network protocols stage 3. Tandem free operation tfo in gsm networks enables transmitting voice transparently trough the core network without transcoding. The bss carries out transcoding of speech channels, allocation of radio channels to mobile phones, paging, transmission and reception. It involves three main subsystems, each containing functional units and interconnected with the others through a series of standard interfaces.
The bts base transceiver station is controlling the radio transmission and the interface to the mobile phones. Current technology permits to decrease the bitrate in gsm radio interface it is 16 kbits for full rate and 8 kbits for half rate. A transcoder according to the invention provides a more efficiently organised architecture in which the at least one transcoder processor, of which there may be many e. Gsm phases 1 and 2 define digital cellular telecommunications system. A logical diagram for the architecture of the signalling links is given in figure 6.
In the us, gsm operates in the bands 850 mhz and 1900 mhz. Transcoding in gsm bss transcoder does conversion of g. Pdf on mar 1, 2010, utsho a arefin and others published a study of cell site planning of gsm. The base station subsystem bss is the section of a traditional cellular telephone network which is responsible for handling traffic and signaling between a mobile phone and the network switching subsystem. A mobile transmits and receives messages to and from the gsm system over the air interface to establish and continue connections through the system 2. Reuse bss architecture new core architecture max theoretical rates 170 kbps gsm circuit switch architecture indirect access to ip network too sensitive connection for data today expensive solution for data network hscsd gsm circuit switch architecture indirect access to ip network too sensitive. The ms and the bss communicate across the um interface. Global system for mobile gsm is a second generation cellular standard developed. The network operator observes and maintains network quality and service offered through the nms. When the fcc issued 1900 mhz to pcs in the united states it was based on gsm. Gsm owns a market share of more than 70 percent of the worlds digital cellular subscribers.
The x2 interface is defined between two neighbour enbs. Cellular and mobile communications questions answers. Day02 gsm network architecture cankaya universitesi. Here is the summer training project in hutch on gsm architecture. Global system for mobile communications gsm is a digital wireless network standard.
The additional components of the gsm architecture comprise of databases and messaging systems functions. If you need a video converter for transcoding, solid signal carries the products you need. Transcoder at the edge is also part of the present document. The pstnisdn switch is a switch for 64 kbits voice. In gsm, the mobile phone is called mobile station ms. The mobile radiotelephone system includes the following subsystems base station subsystem bss network and switching subsystem nss. Next, it describes how to use the image transcoder api package. Four channels are combined in transcoder to provide 64 kbps channel within bss. Temporal scalable mobile video communications based on an. Gsm network architecture, channelisation, signalling and. Objectiv upon es completion of this module the student should be able. It is also known as the air interface or the radio link.
Gsm uses digital communication system or dcs 1800 and is the worlds main 2g standard. Trau one of the most interesting features of gsm is trau. Figure 1 gives an simplified view of the network architecture with the three main network elements bts, bsc and msc. Gsm overview warmly welcome to bundle of my wisdom nifrash. Gprs tunnelling protocol for the user plane gtpu tunnels user data between enodeb and the sgw as well as between the sgw and the pgw in the backbone network.
Gsm operates on the mobile communication bands 900 mhz and 1800 mhz in most parts of the world. Transcoder is a device that takes kbps speech data and multiplexes four of them into standard 64 kbps data. Gsm global system for mobile communications is an open, digital cellular technology used. Transcoders transcoder types in cisco unified communications manager administration. Transcoder type description pernmhd thistype,whichsupportscisco2600xm,cisco2691,cisco3660. The ms is a combination of terminal equipment and subscriber. Gsm fr gsm efr ciscomediaterminationpoint wssvccmm transcoder failover and fallback. The gsm network can be divided into three broad parts. It describes the principles and procedures to support transcoder free operation, tandem free operation and the interworking between trfo and tfo. Gsm supports voice calls and data transfer speeds of up to 9. Each cell is given a cell global identity cgi, a number that uniquely identifies the cell. Gsm architecture in gsm tutorial 18 april 2020 learn gsm.
Gsm global system for mobile communication is one of the most popular system used for mobile telecommunications especially in europe and asia. The transcoder tc thus takes care of the change from one bit rate to another. It was developed by group special mobile of conference europeenne des postes et telecommunications cept and european telecommunications standards institute etsi. This is the area that is paged when a subscriber gets an incoming call. These functions and interfaces are explained in this chapter. The terminal equipment as such is called me mobile. Additional components of the gsm architecture include databases and messaging systems functions. Cellular mobile systems and services tcom1010 2009april gsm architecture 1 gsm network infrastructure2 2 network switching subsystem nss 3 2. Transcoding free voice transmission in gsm and umts. Figure 8 the base station subsystem bss some of the most important bss tasks are listed in the following.
The main task of gsm trau is to compress and decompress the speech data. Given below is a simple pictorial view of the gsm architecture. The mobile station ms the base station subsystem bss the network switching subsystem nss the operation support subsystem oss below is a simple graphical view of the gsm architecture. Isolates calls, a graphical call flow diagram can be created from a call trace. In order to set up a requested call, the call is initially routed to a gateway msc, which finds the correct hlr by knowing the directory number of the gsm subscriber. A gsm network is composed of several functional entities, whose functions and interfaces are defined. Packet controlling unit pcu can be compared to trau function in gsm generally located in the bsc heart of the packet transmission in bss network allow the dynamic traffic allocation provide the radio resource management mechanism. The structure of a gsm network relies on several functional entities, which have been specified in terms of functions and interfaces. To enable an efficient transmission of digital speech information over the air interface, the digital speech signal is compressed. Trau transcoder and rate adaptation unit is an entity to perform a transcoding function for speech channels and rarate adaptation for various data channels. The transcoderrate adaptation unit trau is the data rate conversion unit. Architecture a gsm network consists of several functional entities, whose functions and interfaces are. Aug 10, 2018 transcoder and rate adaptation unit, or trau, performs transcoding function for speech channels and ra rate adaptation for data channels in the gsm category education.
The mobile station is carried by the subscriber, the base station subsystem controls the. Gsm architecture mobile telecommunications networks. Gsm network areas in a gsm network, the following areas are defined. Find, read and cite all the research you need on researchgate. The audiocodes media transcoder mt solution delivers high capacity dspbased transcoding in conjunction with audiocodes fieldproven hardwarebased sbc product family. As is shown in figure 2, the wztosvc transcoder is composed of a wz decoder concatenated with an svc encoder. Its function is the compress and decompress the speech between trau and ms. Gsm network architecture, channelisation, signalling and call. Pdf on jan 1, 2009, jorg eberspacher and others published gsm architecture, protocols and services 3. First, this document explains the basic transcoder api that transcoder, transcoderinput and transcoderoutput define, and thus all transcoders have in common. Gsm global system for mobile communications is an open, digital cellular technology used for transmitting mobile voice and data services. Functional architecture and principal interfaces gateway msc gmsc. In the proposed architecture, the mvs are temporally stored in a buffer and sent to the motion prediction module of svc, where they are processed as described in the following sections. Gsm overview warmly welcome to bundle of my wisdom.
Since msc is basically a pstnisdn switch its bitrate is still 64 kbits. Transcoder and adaptation unit trau the following diagram shows the gsm network along with the added elements. Equipment and the subscribers data is stored in a separate. Bsc and trau does not demand specific environmental conditions to perform operations. Gsm operates on the 900 mhz, 1800 mhz and 1900 mhz. Research open access temporal scalable mobile video. Eng page 2 of 7 1 gsm network infrastructure the following figure depicts a typical gsm network called, public. Trau, referred as transcoding rate and adaptation unit is located as shown in the figure below between bsc and msc or between bts and bsc. We stock a wide variety of transcoders, video converters, and other transcoder equipment. Transcoder and rate adaptation unit, or trau, performs transcoding function for speech channels and ra rate adaptation for data channels in the gsm category education. Bts and ms base station subsystem is a segment of cellular telephone network that is responsible for setting signals and traffic between mobile phone sets and network switching subsystems. Mobility management and speech transcoding bss mobility management mainly covers the different cases of handovers.
About 12 the processing is associated with transcoding speech channel tofrom. A study on call site planning of gsm system from the users point of view, the sim is certainly the bestknown database used in a gsm network. Flag indicate the type of information, traffic or network control. This document is intended for the use of nokia networks customers only for the purposes of the agreement under which the document is submitted, and no part of it may be reproduced or transmitted in any form or means without the prior written permission of nokia networks.
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