gsm-on-the-net-1998046

7/29/2019 gsm-on-the-net-1998046

http://slidepdf.com/reader/full/gsm-on-the-net-1998046 1/8

BackgroundThe handling and sharing of information isof vital importance to the business world.To t his end, many companies have installeda local area network (LAN) to make in -housenetworking and comm unication more effi-cient. Internet/intranet, e-mail and data-bases are a few examples of applications andentit ies accessible from a LAN .

Voice communi cation is handled by a pri-

vate branch exchange (PBX) on the compa-ny premises or by a centrex service in thepub lic switched telephone network (PSTN ).Different solutions have been applied t o theproblem of enhancing wireless telephonywithin the office. The systems most fre-quently used are digital enhanced cordlesstelecomm unications (DECT) and the G SMmacro network (Figure 1).

In DECT, all user services reside in thePBX , whil e all wireless-related services (forexample, roaming and handover) are han-dled by a mobility server. In the case of GSM, new features are introduced in themacro network in order to support typical

office services. For example, home zones

make it p ossible to disting uish between ex-tern al calls and calls made in t he office; vir-tual private networks (VPN ) support pri-vate numbering plans. Radio coverage isachieved either by means of radio base sta-tions (RBS) or different forms of indoorarrangements, such as indoor RBSs withmulticasting antennas. So far, all switch-ing is performed in the macro network.

The PBX market is changing rapidly,however, and sooner or later today’s solu-tions, which are based on proprietary hard-ware and a circuit-switched environment,will be replaced by PBXs operating accord-ing to the Internet protocol (IP). Clearly,therefore, a sustainable, long-term solutionfor GSM in t he office will have to b e basedon IP.

System concept

The pu rpose of G SM on the N et is to serve asa real-time system in a converged networkthat handles all communications within acompany. Voice, data and video will be

processed over a unified IP network: thecompany’s intranet. The system can be ac-cessed in a variety of ways (for example, bymeans of GSM phones, IP phones and PCs)to provide full user mobilit y. Its second keyfeature–terminal mobility–supports roam-ing to the GSM macro network. In otherwords, t he system offers th e convenience of one phone and one number.

The user and terminal m obility providedmeans that G SM on the N et keeps track of auser and his or her terminal’s capabilities,regardless of whether users are in or out sideof the office and wh ether t hey can be reachedover the phone or on a PC.

1 8 4 Ericsson Review No. 4, 19 98

GSM on t he Net

Olle Granberg

GSM on t he Net introduces an entirely new concept for business communi-cations, offering voice, data and multimedia services over corporateintranets. The voice service can be either fixed or mobile (in the latter caseusing GSM access).

GSM on t he Net provides operators and business users wit h a means ofoptim izing personal and organizational c ommunicat ions and work processesby adding terminal and user mobility to their existing IP network.

The author describes GSM on t he Net and different solutions to its imple-ment ation. He also presents a review of ITU-T Recommendat ion H.323 ,which underlies this new business communication system.

Box ATerminology

EndpointA terminal, gateway or multipoint controlunit (MCU) that generates and terminatesinformation streams. An endpoint can init i-ate and receive calls.

PayloadThe actual user information transportedbetween endpoints. (A packet contains

address information and payload.)

Terminal mobilit yA terminal can be moved around geograph-ically without losing contact with the sys-tem.

User mobilityA user can opt to access G SM on the N et indifferent ways. Regardless of whether aphone or a PC is chosen as a means ofaccess, the system wil l keep track of theuser and the terminal’s capabil i t ies.

BTSDECT

Mobility

server

PSTN

PBX

MacroGSMwithVPN

services

Figure 1Present-day office solutions.

7/29/2019 gsm-on-the-net-1998046

http://slidepdf.com/reader/full/gsm-on-the-net-1998046 2/8Ericsson Review No. 4, 19 98 1 8 5

System architecture

General

G SM on the N et is based on ITU -T R ecom-mendation H .323 (Box D), which describesterminals, equipment and services formu ltim edia comm unication over a packet-based n etwork. The b asic concept of H.3 23is that of separating call control (signalingin t he call setup phase) and connection con-trol (data flows between endpoint s). W henthe p ath h as been established, the actual dataflow constitutes a real-time connection be-tween the two (or more) terminals con-cerned.

All nodes in G SM on the N et are connect-ed to the corporate intranet, and commu ni-cation between system nodes and terminals

is handled over t he Int ernet protocol. IP ad-dresses and ports ensure that data and sig-naling flows are routed to the correct desti-nations in the system (or to external net-works).

The corporate intranet can have a verycomplex topology with many routers andwidely scatt ered locations. Even rem ote ter-min als, such as mod em-connected hom e ter-minals or IP- tun neled connections, are in-cluded in th e intranet, thereby forming partof the system (Figure 2).

AN Access nodeAPI Appl icat ion p rogram i nt er faceAUC Au th en tic at io n ce nt erB TS B as e tr an sc ei ve r s ta ti onDECT Digi tal enhanced cordless telecom-

municationsEIR Eq ui pm en t id en tit y r egis te rGPRS General packet radio serviceGSM Global system for mobile communi-

cationHLR Ho me lo ca tio n r egis te rIETF Internet Engineering Task ForceIP Internet protocolISDN Integrated serv ices d ig ita l net -

workIS P In te rn et se rvi ce pro vid er

ITU Internat ional Telecommunication UnionLA Locat ion areaLAN Loc al are a n et wo rkM AP M obi le app li ca ti on par tM CU M ult ipoi nt cont ro l uni tM SC M obi le swi tchi ng cen te rPLMN Publ ic land mobi le networkPSTN Publ ic swi tched telephone networkQo S Qu ali ty o f s er vic eRBS Ra dio bas e s ta tionRSVP Resource reservat ion protocolSM S S ho rt m es s age s er vi ceSoLSA Support of local service areasVLR Vi si ted l ocat ion regi st e rVPN Vi rt ua l p ri va te ne tworkWAN Wi de ar ea ne two rk

WORLD

11:33

CLR

1 2 3

4 5 6

7 8 9

* 0 #

e

O N/O FF

GH337

HLRAUC

EIR

PBX

PSTNInternet

.......

SM Smessage

center

MSC/ BSC

Gate-way

Applicationnode

Accessnode

GSM/ BTS

GSM on the net

IP phone

IP Intranet

Servicenode

WORLD

11:33

CLR

1 2 3

4 5 6

7 8 9

* 0 #

e

ON /OF F

GH337

WORLD

11:33

C LR

1 2 3

4 5 6

7 8 9

* 0 #

e

O N /OF F

GH337

Figure 2A GSM on t he Net system.

Box BAbbreviations

7/29/2019 gsm-on-the-net-1998046


Service nodeTh e service node–which is t he core of G SM

on the N et –is responsible for call setu p, u seradministration, security and oth er system-related services. The functionality of thisnode is what enables user mobility. T he pur -pose of a call is to reach another user; thetype of termin al used by th e called party and

th e location of that party are less important .

Call setup Th e service node controls all calls made be-tween different types of terminal and trans-lates addresses between different types of ac-cess (for instance, between ordinary PSTNphone num bers and add resses in t he system ).Th e setup procedure also involves negot iat-ing terminal capabilities, such as bandwidt hlimitations and man-machine interfaces.

User administration User administration is another importantfunction. Every user has a system identityand a service profile that are registered in

th e service node (Figure 3). The profile listsevery service that the user wants to access;for example, mailbox and call forwarding.

Users access the system b y choosing a t er-minal: a PC, an IP ph one or a GSM phone(locally or in the macro network). If accessis allowed, the user is automatically con-nected t o all services registered in his or heruser profile. H owever, t he m an-machine in-terface or limitations in bandwidth in thechosen access may reduce or inh ibit th e useof some services.

Other basic functions performed by theservice node are authentication, resourcemanagement, and least-cost routing. Thelatter function is responsible for finding themost cost-effective rout e. For examp le, a callfrom an office in Sweden to an office in th eUS can be routed• through a gateway in Sweden and via the

PSTN to th e US subscriber;• through the company intranet to a gate-

way in the US and on to the called sub-scriber.

The service node includes an applicationprogram interface (API) to high-level ap-

plications, such as voice mail and e-mailconvergence, web-initiated dialing, or ver-tical applications, which include sales sup-port, customer-care systems, and order-servicing and log istics systems.

Access nodeThe functionality of the (wireless) accessnode enables GSM terminals to access thesystem. In this sense it resembles the mo-bile switching cent er (MSC), the visited lo-cation register (VLR), and the base stationcontroller (BSC). (The access node will alsocontain functions for supporting generalpacket radio services–GPRS–when t hese be-come available in th e GSM macro network.)


API

Applications

Service node

GSMaccess

Fixedphoneaccess

Fixed term inalaccess, e.g. PC

Figure 3A user’s service profile is stored in the ser-vice node, not in each type of acc ess. Thismeans that all specified services are avail-able to users, no matter what type of termi-nal they use to access t he system.

Box CBenefits of GSM on the Net

For the operator, G SM on the N et offers:• increased GSM traff ic—new subscribers and

lower churn. Furthermore, the businessuser’s behavior pattern, in terms of call ingfrequency and call duration, will transfer toglobal use as well;

• profit margins—if supplied by the operator,system equipment (servers and phones) wil lboost profit m argins through increased prod-uct sales and more service agreements;

• new services— the provision of convergenceservices will generate more revenue. Exam-

ples include service packages , which can betailored to suit individual organizations andvertical market applications.

For the user, G SM on the N et offers:• f reedom at work—the same “look and feel”

wherever the s ystem is accessed (whetherthe user is in the off ice, at a s ubsidiary, athome, or traveling);

• convenience—having GSM integrated intothe office gives the convenience of onephone and one number. The same phone isused, regardless of user whereabouts, with-in or outside of the off ice;

• cost-ef fect iveness—implementat ion costs

are low because existing PCs and LANs areused. Similarly, operation costs are lowthanks to – low-tariff, local traff ic (through local switch ing); – di ff eren ti at ed us er au th or izat ion; – ava ila ble reso urces fo r adm in is trat ion (fo r

example, the IT support team);• adaptabi li ty—the system is a smoothly f i t -

ting part of the existing network environment(and applications ) and can easily be expand-ed and improved with respect to capacity,functional content, and quality;

• scalabil ity—flexible service and applicationdesign (server applications), easy-to-addbase stations and handsets.

7/29/2019 gsm-on-the-net-1998046


ITU-T Recommendation H.323 describes ter-minals, equipment and services for mult i-media comm unication over packet-based net-works (for example, an intranet or theInternet). H.323 terminals and equipmentcan carry real-time voice, data and video, orany combination including video telephony.The scope of H.32 3 does not include the net-work interface, the physical network, or thetransport protocol used on the network.

The network over which H.32 3 terminals com-

municate can be a single entity or multiplesegments with complex topologies. H.323terminals can be integrated into personalcomputers or implemented in stand-alonedevices, s uch as video telephones. Supportof voice is mandatory, while data and videoare optional.

The general approach to the us e of the under-lying transport network in H.32 3 is to employdifferent transport channels for voice, data,video and control, and to provide a means ofsynchronizing packets at the endpoints(Figure D1).

Functional entit ies

Four different functional entities aredescribed in H.323:• Te rm inal• Ga tekeeper• Gateway un i t• Mul t ipoint control uni t (MCU)

Terminal An H.32 3 terminal is an endpoint in the net-work that provides real-time, two-way com-munication with another H.323 terminal–agateway unit or an MCU (in H.323, the term“ endpoint” refers to terminals, gateways andMCUs as elemen ts capable of receiving or ini-tiating calls).

Gatekeeper

The purpose of a gatekeeper is t o provide thefollowing services to the H.323 endpoints:

• Address translation — th e gat ek eepe rtranslates alias addresses into transportaddresses.

• Admission control — th e gat ek ee per a ut ho -rizes network access, based on call autho-rization, bandwidth or some other criteriaselected by the manufacturer.

• Bandwidth control .• Zone management .

The gatekeeper provides the above-mentioned functions for terminals, M CUs and

gateways that have registered with it.

The gatekeeper may also perform optionalfunctions, such as• call-control signaling — th e gat ek eepe r m ay

choose to complete call signaling with theendpoints and process the call i tself. Alter-natively, the gatekeeper may direct the end-points to connect the call signaling to eachother;

• call authorization — th e gat ek eepe r canreject calls from a terminal on the groundsof authorization failure. Other reasons forrejection may include restricted access toor from a specific termina l or gateway, andrestricted access during certain periods;

• bandwidth management — th e gat ek eepe rchecks the number of H.323 t erminals thatare allowed simultaneous access to thenetwork. The gatekeeper can reject callsfrom a terminal if it judges available band-width to be insufficient;

• call management — th e gat ek ee per cankeep a l ist of ongoing H.323 calls. Thisinformation may be necessary to indicatethat a called terminal is busy and to pro-vide bandwidth m anagement data.

Gateway unit A gateway unit is an endpoint in the(packetized) network that provides real-time,two-way communication between H.323 ter-minals in the network and other ITU-T termi-

nals in a wide area network (WAN) or anoth-er H.32 3 gateway. The gateway unit provides

the necessary conversion between differenttypes of terminal. The gateway provides theappropriate translation between transmis-sion and communication procedures. It isresponsible for call setup and clearing onboth the intranet s ide and the circuit-switchednetwork side. The gateway also translatesbetween audio, video and data formats.

Multipoint control unit The multipoint control unit (MCU) consis ts oftwo logical entities: the multipoint controller

(MC) and the multipoint processor (MP).• The mult ipoint control ler controls three or

more terminals that part icipate in a m ult i-point conference. It negotiates capabilitywith the terminals, in order to provide com-mon levels of communication; i t may alsocontrol conference resources, such asmulticasting video.

• The mult ipoint processor is responsible formixing, switching and other processing ofmedia streams under the control of themult ipoint control ler.

Basic call—a summaryThe gatekeep er function controls calls . A callis initiated b y a user (A) at one endpoint. User

A makes the call by entering user B’s nam eor some alias. Terminal A connects to thegatekeeper and requests a connection touser B. The gatekeeper sets up the other partof the connection (between the gatekeeperand user B) and supplies each terminal withits counterpart’s address (IP address andport number).

The two terminals open at least two real-t imedata stream s (one in each direction) betweenthem. Unless some characterist ics of thesess ion change, the gatekeeper performs notasks while a call is in progress. Examplesof changed characterist ics include caseswhere more bandwidth is required (due to achange from, say, voice only to voice and

video) or where a new party is added to thesession.

H.323endpoint

Data transport

Video transport

Voice transportH.323

endpoint

Figure D1Data streams for voice, data and video aretransported on separate channels accord-ing to H.323.

Box D ITU-T Recomm endat ion H.32 3

7/29/2019 gsm-on-the-net-1998046


The access node manages radio resources,

mobility, and comm unication functions. Itcan also interrogate (with MAP/SS7) thehome location register (HLR), and handlesroaming numbers and radio networks; forexamp le, paging and handover control.

Th e access node is involved when calls areset u p t o (or from) a GSM t erminal. The nodeitself does not carry any t raffic, however; itmerely controls communication betweenGSM t erminals.

In t erms of the G SM macro network, theaccess node and its underlying structure of base transceiver stations (BTS) and termi-nals is perceived as an arbitrary MSC/VLRservice area in t he net work.

GSM/ BTS GSM terminals access the system throughth e GSM/BTS, which serves as a gateway be-tween the air interface and the LAN envi-ronment.

In G SM on the N et , a GSM subscription isregarded as a terminal, not as a user sub-scription. In principle, any user who is reg-istered in the system could b e logged on bymeans of an arbitrary GSM mobile phone,but normally a GSM terminal is associated

with a user.

GatewayA gateway is the interconnection betweenG SM on the N et and oth er networks. Exam-ples include interfaces to the PSTN, the

pub lic land m obile network (PLMN), PBXs

and t he Int ernet. The g ateway translates be-tween transmission formats and commu ni-cation procedures. It also translates betweenaudio, video and data formats, includingvoice coders and, as an op tion , video coders(Ericsson’s gateway supp orts H .323 mand a-tory coders and G SM full-rate and enhancedfull-rate coders).

External interface t o PSTN/ ISDN The p ublic switched telephone network canbe reached via ISDN access, either over th ebasic rate interface (2B+D) or the primaryrate interface (ITU-T: 30B+D, ANSI:24B+D).

External interface t o the PLMN The interface to the PLMN can either in-clude signaling only, or b oth signaling andpayload. Basically, signaling between G SM

on th e N et and the PLMN support s GSM mo-bile terminals in the system. Examples of entities that can be reached in the PLMNinclude:• MSC/VLR;• H LR and authentication center (AU);• equipment identity register (EIR);

• message center (for the support of short-message services).

External interface to a PBX The system communicates with the PBXacross a primary rate interface, using the


HLR

Intranet

WORLD

11:33

CLR

1 2 3

4 5 6

7 8 9

* 0 #

e

ON /OF F

GH337

GSM/ BTS

ISP

Small offices

PSTNInternet

.......MSCBSC

Servicenode

Accessnode

Appl.node

Gate-way

R

R

Figure 4Small and medium-size company solution,with an ISP as the carrier.

7/29/2019 gsm-on-the-net-1998046


Qsig signaling protocol. Later, other P BXprotocols may also be supported alongwith a limited set of supplementary ser-vices.

The Internet The Internet interface makes it possible toreach other H .323 networks and t erminals.H ere it should be observed t hat a mult isitecompany is regarded as one G SM on the N et

system.

Application nodeThe application node enables other (high-level) applications to interact with G SM on

the N et over an API. This is in tune with thegrowing trend t oward integrating in forma-tion processing into telecommunications,which will lead to th e development of a newclass of integrated business applications.Some examples of new, advanced conver-gence features made possible by the unifiednetwork that could be implemented into aG SM on the N et environment are listedbelow.• Web-initiated dialing (“Click-to-

Talk”)Users surfing on the net can click on a“phone” icon on t he screen to ret rieve froma directory the ph one numb er of th e per-son or organization they want to call. In-stead of dialing t he num ber, they simplyclick on it t o initiate t he call.A t ypical bankin g application for p eoplewho make their transactions over theInt ernet enables users to get in touch witha bank clerk to discuss a financial matteror to seek assistance.

• Directory-assisted dialingG SM on the N et makes it possible to ini-tiat e a call from th e comp any’s telephonedirectory (or the public directory) in-stead of having to enter t he digits m an-ually.

• Unified messagingAll mail services (voice mail, e-mail, faxmail, video mail) can be conveniently pro-vided in a single mailbox. This service canbe supplem ented wit h a media conversionfeatu re, such as voice-to-t ext and t ext-t o-voice.

• Simplified integration with LAN-based business suppo rt systems

Int egration with customer-care systems,billing systems, order-servicing and lo-gistics systems, sales applications, and soforth . On e example is the autom atic dis-play of customer data and delivery statuswhen a cust omer calls.

Physical implementation

The service and access nodes are imple-mented on st andard servers. This is feasiblebecause the n odes, as specified in H .323 , donot carry any real-time traffic. In a smallsystem, t he functionality of the two n odescan be co-located on one physical server,which may also serve other applications.Large systems might need more than oneservice and access node t o cope with tr afficload.

System configurations

Th e G SM on the N et concept can be config-ured either as a system owned by a compa-ny or as a service provided by a mobile op-erator or an Internet service provider (ISP).The following examp les show t wo differentconfigurations: one for small and medium-sized companies and one for large compa-nies.

Small and medium-sized c ompaniesSmall and medium-sized companies are

likely to choose a solution where a carrier—an operator or an ISP—provides the systemas a service. The ISP’s offering to the smallor medium-sized company is a combineddata/Internet and fixed/mobile telephonysolution. The physical transmission to theoffice (which is normally rat her costly) canbe shared with other services provided bythe ISP. Needless to say, such an arrange-ment is advantageous in terms of datatransmission and even more so from a costperspective.

In t he examp le shown in Figure 4, th e ISPoperates all server-based nodes in GSM on

the N et . The ISP is responsible for interact-ing with the GSM operator in matters re-lated to SS7 transmission links and fre-quency handling. Multimedia is offeredwith in t he range of services provided by theISP; for example, Int ernet access, news, ande-mail.

In the way of new equipment, all that isrequired in the office are access devices; forexamp le, IP phones, GSM base stat ions and,of course, mobile terminals.

Large companies

As a rule, large companies operate theirown system and are also capable of han-dling t heir relation with the PLMN oper-ator. In most cases, a company’s multiplesites are interconnected by means of anintranet.

7/29/2019 gsm-on-the-net-1998046


In the example shown in Figure 5, thelarge office serves its satellite offices with

different system functions. An intranet pro-vides the means of intr a-company commu -nication. This type of large intranet is alsosupported by advanced system functionsthat are capable of finding least-cost routesand locating users roamin g between offices.

Accessing the s ystem

GeneralDifferent types of access are included inG SM on the N et and new ones will be im-plemented in the future. Basically, accesscan be divided into four categories:• Fixed terminals connected to t he intranet.

Examp les include IP phones and PCs withH .323 t erminal software.

• Terminals connected t o the external net-work (the Int ernet). Th is type of termin alis norm ally, but not necessarily, accessedvia a firewall or proxy server.

• Terminals out side of the system; for ex-ample, PSTN phones. This type of ter-min al is accessed via t he gateway.

• W ireless access (GSM access).

A fundamental idea is that user perceptionof services accessed on d ifferent t ypes of ter-

minal should be th e same. At th e same time,it should be borne in mind that an accessmeth od or a terminal m ay have limitationsthat restrict or inhibit the use of a service.

Some types of access might introduce aservice or function t hat is uniq ue from othertypes of access. In such a case, th e inherentservice or function will b e hidden if a simi-lar one exists in the system (for instance,voice mail). The aim is t o support in-systemservices regardless of where access has beenmade. On e example is short nu mbers, whichremain valid even when a GSM mobile ter-minal is roaming in th e macro network.

If a service is uniqu e to a specific type of access, then the system will transport theservice as transparently as possible to theterminal.

GSMGSM access is a key feature of G SM on the

N et . It offers wireless access that can be usedboth within and outside of the office. How-ever, the introduction of GSM in an officeenvironment introduces several new re-quirements. Areas of particular interest are


HLR

WORLD

11:33

C LR

1 2 3

4 5 6

7 8 9

* 0 #

e

ON /O FF

GH337

GSM/ BTS

Office 1

Servicenode

Accessnode

Appl.node

Gate-

way

WORLD

11:33

CLR

1 2 3

4 5 6

7 8 9

* 0 #

e

ON /O FF

GH337

GSM/ BTS

Office 2

Servicenode

Accessnode

Gate-

way

GSM/ BTS

R

WORLD

11:33

C LR

1 2 3

4 5 6

7 8 9

* 0 #

e

O N /OF F

GH337

Office 3

PSTNInternet

.......

MSCBSC

R R

Figure 5Large-company solution.

7/29/2019 gsm-on-the-net-1998046


subscriber handling, radio-network han-dling, frequency handling, charging, andoperation and maintenance. W ithout goingint o detail, th e basic ideas of the G SM on the

N et solution are as follows:• The user should not notice any difference,

no matt er whether the termin al is used inor out side of th e office.

• Services and system behavior are, to th egreatest possible extent , based on GSM on

the N et –not on th e external GSM system.This m eans that G SM on the N et is in con-trol of services in and ou tside of t he office.

• A special, low-tariff charge (or no charge)is applied with in t he system.

RoamingRoaming between internal and externalareas takes place in t he regular way. A loca-tion u pdate is sent to VLR/H LR wh en a usermoves to another location area (LA).

If a mobile terminal is within the office,it is registered in the int ernal VLR (th at is,the VLR functionality in the access node)and th e HLR will indicate that VLR. If theterminal is outside of the office, it is regis-

tered in an external VLR.Even in t he case of handover, G SM on the

N et acts as any MSC/VLR, from the exter-nal G SM system’s point of view.

Service areas and SoLSALow tariffs and m ore advanced services meanthat mobile terminals should, wheneverpossible, be registered in th e office radio net-work. A m obile terminal in active mode iscontrolled by the BSC locating function. Inthis case it would be possible to change thelocating function t o keep t erminals withinthe service area of G SM on the N et . H owev-er, this cannot be done with m obile termi-nals in idle mode. These terminals selectcells by signal streng th only, and t he servicearea will thus coincide with the cell border.

A funct ion called support of local servicearea (SoLSA) will be added to furtherstrengthen the bond between the mobileterminal and the system location area. Thisfunction makes the mobile terminal selectcells belonging to G SM on the N et

(almost) independently of signal strengt h.It forces terminals to stick to the location

area defined by the system. SoLSA func-tionality will soon be added to the GSMstandard.

Quality of s er vice

The resource reservation protocol (RSVP)represents one method of controlling qual-ity of service (QoS); differentiated service isanother meth od. In either case, th e functionmu st be initialized in the network. N etworkelements, such as routers, are normally ca-pable of handling RSVP and differentiatedservice, but in a typical network th ese func-tions are not activated.

RSVP–a complex protocol that more orless emulates a circuit-switched system–results in long call-setup times and will notbe supported by G SM on the N et . Differen-tial service, by contrast, is based on a sim-ple principle and is being standardized byth e Int ernet Engin eering Task Force (IETF).It has already been implemented in severalrouters. G SM on the N et will use differenti-ated service to control qualit y of service.

ConclusionEricsson h as developed a new IP-b ased b usi-ness communication system–G SM on the

N et – t hat offers voice, data and mu ltimediaservices over corporate intranets. The sys-tem enables operators and b usiness users tooptimize their communications by addingterminal and u ser m obility to th eir existingIP network.

G SM on the N et serves as a real-time sys-tem in a converged network that handles allcommunications within a company. Itsmulti-access feature ensures user mobility,while terminal mobility supports roamingto the GSM macro network. That way, thesystem offers the convenience of one phoneand one number.

Th e int egration of informat ion processinginto t elecomm unications will lead to the d e-velopment of a new class of int egrated b usi-ness applications, and t his is where the newsystem comes in handy. A wid e range of ad-vanced convergence features made p ossibleby a unified network can be implementedin a G SM on the N et environment.

Documents

gsm-on-the-net-1998046