T-MOBILE EXHIBIT 1107
`
`T-MOBILE EXHIBIT 1107
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`

`

`1922
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`Edited by G. Goos, J. Hartmanis and J. van Leeuwen
`
` Lecture Notes in Computer Science
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`

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`
`
`
`Jon Crowcroft James Roberts
`MikhailI. Smirnov (Eds.)
`
`Quality of Future
`Internet Services
`
`Berlin, Germany, September25-26, oe 2000
`S
`;
`First COST 263 International Worksho
`fl
`Proceedings
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`
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`Q; Springer
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`I Asios
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`Series Editors
`
`Gerhard Goos, Karlsruhe University, Germany
`Juris Hartmanis, Comell University, NY, USA
`Jan van Leeuwen, Utrecht University, The Netherlands
`VolumeEditors
`Jon Crowcroft
`University College London, Department of Computer Science
`GowerStreet, London WCIE 6BT, United Kingdom
`E-mail: jon.crowcroft@cs.ucl.ac.uk
`James Roberts
`France Telecom R&D
`38 rue de Général Leclerc, 92794 Issy-Moulineaux, Cedex 9, France
`E-mail: james.roberts @cnet.francetelecom.fr
`Mikhail I. Smirnov
`GMD FOKUS
`Kaiserin-Augusta Allee 31, 10589 Berlin, Germany
`E-mail: smirnov @fokus.gmd.de
`
`Cataloging-in-Publication Data applied for
`
`__Die Deutsche Bibliothek - CIP-Einheitsaufnahme
`*.
`Qualit}\of future Internet services: first COST 263 international
`workshop ; proceedings / QofIS 2000, Berlin, Germany, September
`23 - 26, 2(100. Jon Crowcroft... (ed.). - Berlin ; Heidelberg ; New York;
`Barcelonaj; Hong Kong ; London; Milan; Paris ; Singapore ; Tokyo :
`Springef;2000
`ectufé motes in computer science ; 1922)
`<BBN 3-40-41076-7
`;/
`
`YOFCONG
`
`ae B
`ed
`
`f*
`é
`a CFSubject Classification (1998): C.2, H.4, H.3, J.1
`
`ISSN 0302-9743
`ISBN 3-540-41076-7 Springer-Verlag Berlin Heidelberg New York
`
`This work is subject to copyright. All rights are reserved, whether the whole or part of the material is
`concerned, specifically the rights oftranslation, reprinting,re-use of illustrations, recitation, broadcasting,
`reproduction on microfilms or in any other way, and storage in data banks. Duplication ofthis publication
`or parts thereofis permitted only underthe provisions of the German Copyright Law of September 9, 1965,
`in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are
`liable for prosecution under the German Copyright Law.
`Springer-Verlag Berlin Heidelberg New York
`a memberof BertelsmannSpringer Science+Business Media GmbH
`© Springer-Verlag Berlin Heidelberg 2000
`Printed in Germany
`‘Typesetting: Camera-ready by author, data conversion by DA-TeX Gerd Blumenstein
`Printed on acid-free paper
`SPIN: 10722832
`06/3142
`543210
`
`

`

`IX
`
`Table of Contents
`
`Ix
`
`An
`
`TCP, Flow and Congestion Control
`
`.. 55
`
`lay Boundsin a Network with Aggregate Scheduling ......-......-05---054 1
`- Charny and Jean- Yves Le Boudec
`A Queue Management System for Differentiated-Services IP Routers ....... 14
`Goncalo Quadros, Antonio Alves, Joao Silva, Henrique Matos,
`Bdmundo Monteiro and Fernando Boavida
`Modeling the Dynamics of the RED Algorithm ..........6:06ssseeeeeere ees 28
`Pasi E. Lassila and Jorma T. Virtamo
`
`
`h queueing and Scheduling
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`
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`
`
`
`
`
`
`
`
`
`The Direct Adjustment Algorithm:
`.68
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`
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`Dorgham Sisalem and Henning Schulzrinne
`
`
`On ACK Filtering on a Slow Reverse Channel 0.2.5.5. 555250555555 cn aees 80
`Chadi Barakat and Eitan Altman
`
`
`
`
`
`Design, Implementation and Test of a RSVP Agent Based
`on a Generic QoS API
`#eeetiivieierees en Pee Ee ee Ge ee 93
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`Esteve Majoral-Coma, Xavier Martinez-Alvarez, Angel Luna-Lambies
`
`and Jordi Domingo-Pascual
`
`
`On the Feasibility of RSVP as General Signalling Interface ..............-. 105
`Martin Karsten, Jens Schmitt, Nicole Beriér and Ralf Steinmetz
`
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`Field-Trial of Dynamic SLA in Diffserv-Capable Network .............05: ed
`
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`Random Early Marking ............2000200ssseuueeenee sees detest eens e ese 43
`Sanjeewa Athuraliya, Steven Low and David Lepsley
`A Markovian Model for TCP Analysis in
`a Differentiated Services Network .........2.. 0555565
`Chadi Barekat and Eitan Altman
`
`ee
`
`sue eee eee eees
`
`A TCP-Friendly Adaptation Scheme ....,..----- 26:6cseeener eee ees os
`
`End-to-End
`
`Naoto Morishima, Akimichi Ogawa, Keijiro Ehara and Youki Kadobayashi
`
`

`

`x
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`Table of Contents
`
`
`Traffic Engineering, QoS Routing
`Choosing the Objectives for Traffic Engineering in
`IP Backbone Networks Based on Quality-of-Service Requirements ....--++-
`Fabrice Poppe, Sven Van den Bosch, Paloma de La Vallée-Poussin,
`Hugo Van Hove, Hans De Neve and Guido Petat
`On the Cost of Using MPLSfor Interdomain Traffic ..-s00s5 _scenouatranaedAM
`Steve Uhlig and Olivier Bonaventure
`Mechanismsfor Inter-domain QoS Routing
`in Differentiated Service Networks
`....--+: Salus aces cuanamane kets
`Peng Zhang and Raimo Kantola
`
`
`
`153
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`
`
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`
`ee
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`al|
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`QoS Measurements and Measurement Based QoS Mechanisms
`Priority Queueing Applied to Expedited Forwarding:
`A Measurement-Based Analysis ....s.0eeerrseneee eens
`: baa a 167
`Tiziana Ferrari, Giovanni Pau and Carla Raffaelli
`QoS/GOS Parameter Definitions and Measurement
`[Muaaeauwaa
`vate ga ereeane ttt
`182
`in IP/ATM Networks ..--..++. ++: ait
`Jorma Jormakka and Kari Heikkinen
`QoS Assessment and Measurement for End-to-End Services ..-+:+++ (gage 194
`Torsten Bissel, Manfred Bogen, Christian Bonkowski and Dieter Strecker
`
`Fairness
`
`.. 245
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`
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`
`
`euhEp eae208
`The Fairness Challenge in Computer Networks ...-.
`
`
`Robert Denda, Albert Banchs and Wolfgang Effelsberg
`A Multi-color Marking Scheme to Achieve Fair Bandwidth Allocation ...-- 221
`
`Kenny Pauwels, Stefaan De Cnodder and Omar Ellouma
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`Traffic Phase Effects with RED and Constant Bit Rate
`awwenaedebeluaacea ys
`coy
`dpew ceeacemt Seuvehes ee
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`UDP-Based Traffic .--.-
`Lohmar, Martina Zitterbart and Ralf Keller
`Jérg Diederich, Thorsten
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`
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`Adaptation
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`Adaptive Hybrid Error Control for IP-Based Continuous
`Media Multicast Services ...++.s+srstrente rt? | cag MER
`Georg Carle, Henning Sanneck and Mirko Schramm
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`Efficient Shaping of User-Specified QoS Using Agegregate-Flow Control ....259
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`Huan Ren and Kihong Park
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`eaESteen-
`5eeeeeee9gga)| +
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`Table of Contents
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`272
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`XI
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`of Heterogeneous Multicast Distribution Trees
`Construction
`Active MeGwOtle apa: meat penbeaeer wnen DT
`sing Filtering in an
`ki Murata and
`Héctor Akamine, Naoki Wakamiya, Masayu:
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`fideo Miyahara
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`qpraffic Classes and Charging
`Approachto Support Traffic ClassesinIP Networks ...--.-sssct285
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`ncalo Quadros, Antonio Alves, Edmundo Monteiro and
`An
`Go
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`ng in the Future Internet ...---+°300
`o Boavida
`Feernand:
`
`n Framework for Prici rv and Klaus Wehrle
`Elements of an Ope
`t Ritter, Jochen Schille
`Jan Gerke, Hartmu
`d Billing Models for GSM and
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`on of Charging an
`Evoluti
`Mobile Internet Services
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`Future
`hnie, David Hutchison an
`John Cus
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`Resource Utilization and Performance
`LiveVideo Scheduling in Differentiated ServicesInternet .-.---0.e324
`
`Themistoklis Rapsomanikis
`Virtual Routers: A Novel Approach for QoS Performance E
`
`
`Florian Baumgartner and Torsten Braun
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`DSRUP: A Resource Updating Protocol for
`
`the Differentiated Services Environment
`....-ss-srenresree ee
`Joo Ghee Lim, Brahim Bensaow and Kee Chaing Chua
`
`
`
`
`Internet Charging
`Keynote Talk: Internet Gearitigs vopav ne rnse nr tenerenbnesrnoeeess TET”
`
`Andrew M. Odlyzko
`
`Dsjssethanging Tots gaabyrieacrancrnontnurmsrtmn SSPE”
`Georg Carle
`
`
`corso flee eatoue maacon.coof antennae fer “NaS ARES ©
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`d Huw Oliver
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`312
`
`valuation ..+--: 336
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`348
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`360
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`361
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`367
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`

`

`Evolution of Charging and Billing Modelsfor GSM and
`Future Mobile Internet Services
`John Cushnie', DavidHutchison’, andHuw Oliver’
`
`' Distributed Multimedia Research Group
`Lancaster University, UK
`{j.cushnie,d.h}@lancaster.ac.uk
`2 Internet Research Institute
`HPLabs, Bristol, UK
`heo@hplb.hpl.hp.com
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`Abstract. Mobile telephone communications and the Internet are
`converging and may eventually operate on a common technical
`platform, using TCP/IP networks as the main backbone medium.
`Mobile telephones are converging to Internet terminals, allowing the
`user access to email, Web browsing andall the other Internet services
`currently available from a desktop computer environment. In order to
`provide improved infrastructure for Global System for Mobile (GSM)
`based Internet services using 2™ and 3generation (2G and 3G) the
`mobile network providers have the requirement to generate revenue for
`the services they provide. To do this the mobile network providersfirst
`need to capture the charging andbilling data from the network. This
`paper describes the evolution of the GSM telephone networks and
`future mobile Internet services, via the General Purpose Radio Service
`(GPRS) and Universal Mobile Telecommunication System (UMTS).
`The methods for collecting the charging andbilling information and
`charging models for processing this data into subscriber bills are
`discussed. A selection of proposed Internet charging models are applied
`to the mobile network marketandtheir relative suitability is examined.
`Keywords: 1G, 2G, 3G, GSM, GPRS, UMTS,Charging,Billing, Mobile, Internet.
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`1
`Introduction
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`The Global System for Mobile (GSM) was
`first
`introduced in 1992
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`approximately 23 million subscribers, rising to over 200 million in 1999 on Over=
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`GSM networks [1]. The aim wasto provide a global mobile telephonenetwork&
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`could be implemented using standard building blocks not tied to specific hare
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`far higher than any WS
`vendors. The uptake of GSM by subscribers is
`predictions andtypifies the 1990’s and the increasing need for personal mobil ty
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`1* generation (1G) GSM mobile networksprovide subscribers with high quae
`communications and low bandwidth data connections for FAX, Short "a
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`J. Crowcroft, J. Roberts, and M. Smirnov (Eds.): QofIS 2000, LNCS 1922,pp. 312-323, 200
`© Springer-Verlag Berlin Heidelberg 2000
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`Evolution of Charging and Billing Models
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`Service (SMS)and full dial-in connection to the Internet for email and web browsing,
`usually requiring a mobile computer or intelligent handset. The addition of overlay
`communication protocols, such as Wireless Application Protocol (WAP) [2], allow
`mobile handsets on 1G GSM networks to be used for secure connection applications
`such as mobile banking andother transaction based services. International roaming
`agreements between the numerous mobile network providers allow subscribers to be
`reachable almost anywhere in the world where there is GSM coverage using the same
`telephone number and handset. Satellite based services such as GlobalStar [3] and
`ICO [4] allow GSM subscribers to further expand their network coverage and
`availability using the same mobile communications infrastructure. The increasing use
`of mobile telephones and devices for data communication drives the need from the
`market for a fast, reliable and available infrastructure. GSMproposesto provide the
`required infrastructure using 2™ and 3° (2G and 3G) generation GSM which
`introduce new technology that allows increased data bandwidths and new data
`services [1]. 2G GSM introduces the General Packet Radio Service (GPRS) and 3G
`GSMintroduces the Universal Mobile Telecommunication System (UMTS).
`The introduction of 2G and 3G GSMtechnology brings convergence of GSM mobile
`networks with the Internet. Packet Switching [5]is being introduced as the switching
`mechanism for data calls and Internet sessions, in contrast with the current circuit
`switching implementations currently used in 1G GSM and fixed line telephony
`networks. The 2G and 3G technologies deliver the same services available from the
`desktop Internet
`today,
`including email, secure transactions and Web browsing
`becomeavailable on mobile devices, using the standard infrastructure ofthe Internet.
`In order for the mobile networks to be able to offer these additional services to the
`customersthere is a. requirementfor the recovery ofthe infrastructure investmentcost.
`This is a prime justification and motivation for charging andbilling for telephone
`network usage together with the need for generating commercial profits for telephone
`network shareholders and companies. Charging may also be used to provide
`congestion control in under-provisioned and over-subscribed networks.
`2G and 3G GSM networks present the operators with many charging and billing
`challenges. The experience gained with charging andbilling with GPRS will prove
`valuable when UMTSis being rolled out in GSM networks. There are various
`proposed economic and technical models for charging and billing for Internet usage.
`Most of these are equally suitable for charging and billing of mobile network traffic,
`especially with 2G and 3G GSM systems.
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`2 GSM Mobile Networks and the Future Internet
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`1G GSM networks[1] provide high quality digital telephony with low bandwidth data
`communications for FAX and SMS. GSM networks are typically multi-vendor and
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`consist of a layered architecture including the mobile handsets, the telephone network
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`and the subscriber invoices andbills. The Base Station and the Network Subsystems
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`are often referred to as the Operational Network (ON), and is usually physically
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`distributed around the area of coverage of the GSM network. The ON elements are
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`often sited remotely with wide area networking (WAN) connectivity to the rest of the
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`network to allow centralised remote administration of the network. The Base
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`314
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`John Cushnie etal.
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`Transmitter Stations (BTS) and the Base Station Controllers (BSC) provide the air
`interface for GSM, whichis then circuit switched [5] using the industry standard $S7
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`switching by the Mobile Switching Centers (MSCs) in the ON. Additional Gateway
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`MSCsallow switching to other mobile and fixed line telephone networks, providing
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`interconnection and roaming. Billing tickets for all calls made in the network are
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`produced on the MSCs,based on subscriber Ids in the network.
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`The Operational Support Systems (OSS) provides the interface to the customer
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`invoices
`and bills,
`and normally includes
`systems
`for billing,
`subscriber
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`administration, GSM Subscriber Identification Module (SIM) chipcard production,
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`fraud detection, voicemail and off-line data-mining and analysis systems. Most
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`mobile networks de-couple the ON from the OSS using Mediation Systems or
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`Mediation Devices (MD). These systems are used to collect billing data from the ON
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`and also to manage the subscriber databases in the ON elements.
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`The collection of the billing data is normally via high-speed communication links
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`using reliable data protocols such as File Transfer and Management (FTAM) and
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`X.25. Once billing data is collected centrally it can be processed into subscriber
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`invoices and bills using dedicated billing systems and the mobile network’s charging
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`tariffs. The billing data can also be further processed by additional data-mining
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`systems to detect subscriber’s usage patterns, possible fraud detection and subscriber
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`profile surveying.
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`With 2G GSM the General Packet Radio Service (GPRS) [1,6,7] is introduced
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`providing an overlay service for Internet access that shares the sameair interface as
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`1G GSM. The design goal behind GPRS is to provide high-speed Internet data
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`communications for mobile devices and subscribers using the existing 1G GSM air
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`interface,
`thereby minimising the cost
`impact on the existing installed network
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`infrastructure. GPRSis implemented in an existing GSM network with the addition of
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`two new ON elements the Signalling GPRS Service Node (SGSN) and the Gateway
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`GPRSService Node (GGSN).
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`Additional modifications to the existing BTS and BSC to include Packet Control
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`Units are also required so that the network is GPRS aware. The two new ON elements
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`provide the interface between the GSM air interface and the TCP/IP network used for
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`the GPRS specific traffic, (i.e. Internet sessions used for email, http, ftp etc). GPRS
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`has the advantages ofdigital telephony of GSM combined with increased bandwidth
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`overthe air interface for data traffic. The GGSN and SGSNin the ON provide the
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`switching for the mobile data sessions and use packet switching [5]. GPRS data
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`sessions are routed by the MSCs as for 1G GSM with the SGSN and GGSNrouting
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`the Internet sessions to the TCP/IP network, using packet switching [5]. Packet
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`switching makes full use of the available bandwidth of the underlying network, but
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`often has a reduced Quality of Service, and is suited to ‘bursty’ ‘network traffic
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`including Internet protocols such ashttp, ftp, email etc, where guaranteed qualities of
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`service are not a top priority.
`In addition to introducing TCP/IP packet switching
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`GPRSequipped mobile networks may roll in IPv6 [8] as the preferred IP protocol.
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`This will allow the large number of addressable network nodes that will be required
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`when there is a high saturation of mobile devices requiring Internet connectivity.
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`The GGSN and SGSNproduce billing tickets andstatistical data relating to Internet
`traffic usage generated by GPRS calls and sessions.
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`Evolution of Charging and Billing Models
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`315
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`2G and 3G GSMbringswith it a new set of parameters to the challenge of billing and
`charging subscribers for using the GSM mobile networks. Mobile network subscribers
`are normally charged on a time and usagebasis for the high quality telephony. With
`2G and 3G GSM there are new possibilities to charge the subscribers for how much
`data or bandwidth they use in the network, in addition to the amount of talk-time
`consumed. This shares commonality with the possibilities currently being proposed
`for Internet charging andbilling. As in the Internet the cost of packet counting may
`be more expensive than the value of the packets being counted. These new challenges
`need to be met and addressed by the network operators.
`3G GSM mobile networks arrive with the introduction of Universal Mobile
`Telecommunication System (UMTS). This will be based on the standard ON and OSS
`GSMarchitecture with the addition of UMTSspecific Network Elements. It will build
`on the infrastructure installed for GPRS with a marked increase in maximum
`bandwidth to 2Mbits/sec [1].
`Supported applications for 2G and 3G GSM may involve Internet intensive activities
`such as web browsing and email communication, as well as traditional mobile
`telephony. Table 1 shows a comparison of the bandwidth and communication rates
`achievable with the different generations of GSM networks[1].
`
`
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`Generation
`
`ou
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`2001
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`Table 1. GSM Architecture Generations
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`Max. Data Bandwidth
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`Technology
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`GPRS
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`115 Kb/sec Direct Internet connection
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`pow|1995 SMS &MobileData&FAX 9.6 Kb/secInternetviaModem
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`UMTS
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`2 Mb/sec Direct Internet connection
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`2002/3
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`The introduction of GPRS is considered a stepping stone to the promises and
`functionality of UMTS and high-speed access to Internet services and Networking.
`Many mobile network operators view the experience to be gained with GPRSand the
`associated billing issues essential for the implementation of systems for UMTSasit
`may be too late to learn when UMTSis implemented and available for the mass
`market. The systems and methods developed for GPRS charging and billing need to
`be compatible with the requirements of UMTSto ensure preservation of investment,
`infrastructure and knowledge.
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`3
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`Infrastructure for Charging and Billing
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`In order to charge for mobile telephony services the network operator has to first
`capture the network usage of all of the network’s users including subscribers and
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`roaming subscribers. This usage data then needs to be processed andthen set against
`the billing and charging models andtariffsin use.
`Billing tickets need to be collected and processed centrally so that the subscriber bills
`can be produced. Thecollection ofbilling tickets is often done by a mediation system,
`These systems may also carry out vendor specific translations on the billing ticket
`formats so that multi-vendor ONs can be implemented, or to allow the native billing
`tickets to be used on commercialbilling system,or on other centralised OSS systems
`used for data-mining. The heterogeneous nature ofmost mobile networks may be very
`problematic with many different file formats and standards being involved. Onceall
`the billing tickets have been collected and pre-processed into a standard format that
`the billing and other OSS systems can understand they may them be used to produce
`the invoices andbills for the subscribers.
`The ETSI [1] standards recommend a Charging Gateway Function (CGF)to handle
`the billing record generation. Twobilling records are generated, one by the GGSNfor
`the Internet part and one by the SGSNforthe mobility (radio) part.
`Current GSM billing systems have difficulties implementing charging for 1G GSM
`nhon-voice services and it is unlikely that existing billing systems will be able to
`process the large number ofnew variables introduced with 2G and 3G networks.
`An added complication for GPRS charging is the overlap and convergence to the
`Internet and the multitude of diverse systems connectedtoit. In addition to the inter-
`charging between the mobile and fixed telephone networks inter-charging between
`the mobile networks and Internet providers will be required and this will add to the
`operational costs of running the 2G and 3G services in parallel to the 1G GSM
`network. With the already proposed Internet charging models the inter-charging
`between the mobile and Internet network providers has the potential to become very
`complicated and may include requirements for additional billing and charging
`systems for the required accounting. The addition of GPRS to the GSM mobile
`network modifies the call flows for Internet packet data as in Figure 1 and includes
`the required gatewayto Internet services and external networks:
`
`3
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`John Cushnie etal.
`316
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`Fig. 1. GSM 2G GSM Call Flow with GPRS
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`n set against
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`Network operators may also have packet counting systems in the network that will
`produce additional billing and charging information that may require processing by
`the billing systems.
`The GPRSrelatedbilling tickets may be of a different format to the ones produced by
`the MSCs and mayinclude data on the amounts of packets exchanged during GPRS
`sessions. Extensions to the mediation methods may be implementedfor the collection
`and pre-processing of the GPRSrelated billing tickets that may then be fed to the
`billings systems. For 3G there will be the addition of UMTS Mobile Switching
`Centers (UMSC) for UMTSspecific traffic.
`Once thebilling ticket information has been collected from the network the mobile
`network requires a billing and charging system to make sense of all the data and
`produce the invoices and bills for the subscribers, and also to produce the cross-
`charge data for partner network providers. The actual cost of providing and
`maintaining such a billing system may be anything up to 50% of the total
`infrastructure investment and annual turnover of the mobile network. The billing
`system therefore needsto be able to provide a good deal of added value to make the
`investment worthwhile. This provides a valid justification for simplifying the billing
`function and investigating the use of charging models based on fixed price
`subscriptions and bulk purchaseoftalk time and data bandwidth in the network.
`Most mobile network operators currently offer contract subscriptions, whichinclude a
`line rental elementplus a contract rate for telephony airtime, usually based on call
`duration. In addition to the contract subscriptions the network operators offer “pre-
`paid’ contracts where the subscriber pre-pays for the airtime used in the network.
`From a commercial viewpoint pre-paid makes sense for the network operators, since
`they will receive payment from subscribers prior to the consumption of resources.
`This simplifies revenue collection, but with the downside of increased complexity in
`the ON to prevent subscribers from over-spending on their ‘pre-paid’ subscription.
`With the addition of Internet access via GPRS and UMTSexisting mobile network
`subscriptions need to be extendedto include charging for the Internet services used by
`the subscribers. Just how to charge for the Internet services offered to and used by the
`subscribers is the major challenge to the mobile network providers.
`In most commercial environments some kind offraud is normally present. Mobile
`networks are no exception. The vast array ofbilling ticket information produced by
`the ON in mobile networks can be processed offline and used effectively for fraud
`detection. Again the infrastructure investments for such systems are high and their
`added value has to be proved. Fraud detection fits quite nicely into the billing and
`charging models and they often go hand in hand. An example of fraud in GSM
`networks is the running up of large bills on stolen mobile phones. This can be
`detected using the billing data and the mobile phone being used can be blocked in the
`network, but incurs a high cost in the real-time monitoring of the network traffic data
`and the associated systems and staff. With the addition of 2G and 3G GSM the
`opportunity for fraud increases and the network operators peed to be aware of the
`different kinds offraud that are possible and may occur.
`
`cludes Evolution of Charging and Billing Models
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` SSPotealoralf=2“a
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` 318 John Cushnieet al.
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`4 Charging Models
`
`There are many charging models that have been proposed [9] for the current and
`future Internet as well as those traditionally employed by the mobile and fixed line
`telephone networks. Most, if not all, of the Internet charging models are equally
`applicable for use in the mobile networks, especially with the introduction of 2G and
`3G GSMsystems. Below is a discussion of someofthe proposed charging models,
`and how they can be adaptedto the mobile network markets.
`
`
`
`=ee,SeeSeea
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`Metered Charging
`This pricing modelis already in use with many Internet service providers (ISPs) and
`European mobile and fixed line telephone networks. The modelinvolves charging the
`subscriber for the connection to the service provider on a monthly basis and then
`charging for metered usage of the service. The usageis usually measured in units of
`time and there is often a ‘free’ period of usage included with the monthly fee.
`Variations on this model include having scaled subscription charges that increase with
`the metered usage.
`in 2G and 3G GSM networks may become commercially
`The use of this model
`problematic since subscribers may leave GPRSsessions open endlessly without the
`handset being powered on. Metered charging based on time for such usage may prove
`prohibitive. However, if the usage is based on other session parameters, for example
`number of packets transmitted/received, then the commercial impact becomesless
`and the model maybe usable in mobile networks fordata.
`
`Fixed Price Charging
`This pricing modelis similar to that used by some USfixed line telephone networks
`for local call charging. The network service providersets a fixed rental charge for the
`telephone connection andall local calls are then free of charge with metered charging
`used for long-distancecalls.
`The advantage of this charging modelis that call data for local calls does not need to
`be collected and processed, providing a commercial saving for the network operator
`in the billing systems and mediation systems infrastructure.
`Disadvantages of this model include no added revenue for the service providers in
`times of above average usage on the network, and congestion may also become an
`issue if the network is under provisioned for the number of possible subscribers at
`peak times. This provides a strong argumentfor using charging and billing to improve
`congestion control by dissuading subscribers from using the network through higher
`cost for the providedservices.
`
`ee
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`Packet Charging
`Packet Charging is specific to Packet Switching [5] networks and involves the
`capturing and counting the number of packets exchanged in a session. This is @
`proposed method of metering Internettraffic and being able to cross-charge between
`networks
`as well as
`ISP and mobile subscribers. This model
`requires
`the
`implementation of packet counting systems in the network and complex billing
`systems that can process the packet data on a subscriber and customerbasis.
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`Evolution of Charging and Billing Models
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`319
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`The advantage of this method of charging is that the absolute usage of the network
`and services can be metered,calculated andbilled for very accurately, as long as the
`packet information can be capturedefficiently.
`The major disadvantage of Packet Charging is that the cost of measuring the packets
`may be greater than their actual value, both from an infrastructure investment and
`additional networktraffic viewpoint. This may lead to packet charging being used as
`a policing tool to ensure that network bandwidth is used efficiently and not over
`consumed by the network subscribers, rather than as a direct charging model.
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`Expected Capacity Charging
`This charging mode] [9] allowsthe service provider to identify the amount of network
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`capacity that any subscriber receives under congested conditions, agreed on a usage
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`profile basis, and charge the subscriber an agreed price for that level of service. The
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`subscribers are charged for their expected capacity and not the peak capacity rate of
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`the network. Charging involves usingafilter at the user network interface to tag
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`excesstraffic; this traffic is then preferentially rejected in the network in the case of
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`network congestion but
`is not charged for; charges are determined by the filter
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`parameters.
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`This model has the advantage that the price to the subscriber is fixed and predictable
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`which in turn permits the network provider to budget correctly for network usage. The
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`expected capacity model also gives the network provider a more stable modelof the
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`long-term capacity planning for the network. This model fits is well with mobile
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`networks and the administration of the agreed expected capacity would be doneas
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`part ofthe normal subscriber administration tasks.
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`Onedisadvantage is that the network operator hasto police the actual capacity of the
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`network used by subscribers and act accordingly by limiting the subscribers service to
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`whathas been purchased, or by invoicing the subscriber for the extra capacity used,
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`on a meteredtariff for example.
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`Edge Pricing
`Proposedin [10] this model charges for the usage at the ‘edge’ of the network scope
`for the subscriber, rather than along the expected path of the source and destination of
`the calling session. The networks in turn then cross-charge each other for the usage at
`the network ‘edges’.
`Edge pricing refers to the capture of the local charging
`information. Once captured the information can be used for any kind of charging
`including metered, fixed or expected capacity, for example. Past research [13] has
`shown that much of the observed congestion on the Internet is at the edges of the
`individual networks that make up the Internet. The use of edge pricing may be
`effective as a policing method to monitor andalert the network operators to such
`congestion.
`This approach hasthe advantagethatall session data can be captured locally and does
`not involve exchangingbilling data with other networks and partners for subscriber
`billing, as for current roaming arrangements between mobile networks.
`A disadvantage with this model is the lack of visibility of the routing via external
`networks andthe costs ofthat traffic to both networks. The cost of collection of the
`data may again also be an influencing factor in the selection of this method, as for
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