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

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

`
`
`
`Jon Crowcroft James Roberts
`Mikhail I. Srnirnov (Eds.)
`
`Quality of Future
`Internet Services
`
`Berlin, Germany, September 25f)2r6,S28gb99flS 2000
`First COST 263 International W k h
`
`Proceedings
`
`

`
`
`
`Series Editors
`
`Gerhard Goos, Karlsruhe University, Germany
`Juris Hartmanis, Cornell University, NY, USA
`Jan van Leeuwen, Utrecht University, The Netherlands
`
`Volume Editors
`
`Jon Crowcroft
`University College London, Department of Computer Science
`Gower Street, London WClE 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. Smimov
`GMD FOKUS
`
`Kaiserin-Augusta Allee 31, 10589 Berlin, Germany
`E—mail: smimov@fokus.gmd.de
`
`Cataloging-in—Publication Data applied for
`
`_
`
`I115 lleutsche Bibliothek - CIP-Einheitsaufnahme
`\
`
`Qua1it\y\of future Internet services : first COST 263 international
`.é.V9l‘kSh-1% ; proceedings / QofIS 2000, Berlin, Germany, September
`‘egg - 26, '_"I;l00. Jon Crowcroft
`(ed.). - Berlin ; Heidelberg ; New York ;
`Barcelonul; Hong Kong ; London ; Milan ; Paris ; Singapore ; Tokyo :
`Springer},-_I:000
`‘Tieectui-é hotes in computer science ; 1922)
`{gm 3—,t40—41o76-7
`.n'xn'
`
`/
`“* cttsubject Classification (1998): c.2, H.4, H.3, 1.1
`
`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 of translation, reprinting, re-use of illustrations, recitation, broadcasting,
`reproduction on rnicrofilms or in any other way, and storage in data banks. Duplication of this publication
`or parts thereof is permitted only under the 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 Gennan Copyright Law.
`
`Springer-Verlag Berlin Heidelberg New York
`a member of Bertelsmannspringer Science+Business Media GmbH
`© Springer-Verlag Berlin Heidelberg 2000
`Printed in Germany
`
`Typesetting: Carnera-ready by author, data conversion by DA-TeX Gerd Blumenstein
`Printed on acid-free paper
`SPIN: 10722832
`06/3142
`5 4 3 2 1 0
`
`

`
`Table of Contents
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`IX
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`eueing and Scheduling
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`.Qu
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`Delay Bounds in a Network with Aggregate Scheduling .
`Anna, C7zarny and Jean- Yves Le Bovdec
`A Queue Management System for Difierentiated—Services IP Routers .
`Goncalo Quadros, Antonio Alves, Joao Silva, Henrique Matos,
`Edmundo Monteiro and Fernando Boavida
`Modeling the Dynamics of the RED Algorithm .
`P051‘ E, Lassila and Jorma T. Virtamo
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`TCP, Flow and Congestion Control
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`Random Early Marking .
`Sanjeewa Athuraliya, Steven Low and David Lapsley
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`. 55
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`A Markovian Model for TCP Analysis in
`a Differentiated Services Network .
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`Chadi Barakat and Eitan Altman
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`The Direct Adjustment Algorithm:
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`A TCP-Friendly Adaptation Scheme
`Dorgham Sisalem and Henning Schulzrinne
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`On ACK Filtering on a Slow Reverse Channel
`Chadi Barakat and Eitan Altman
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`End-to-End
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`Design, Implementation and Test of a RSVP Agent Based
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`on a Generic QoS API
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`Esteve Majoral-Coma, Xavier Ma1'tinez—Alvarez, Angel Lvna—Lambies
`and Jordi Domingo—Pascual
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`On the Feasibility of RSVP as General Signalling Interface .
`Martin Karsten, Jens Schmitt, Nicole Beriér and Ralf Steinmetz
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`Field—T.rial of Dynamic SLA in Diffserv—Capable Network .
`Naoto Morishima, Akimichi Ogawa, Keijiro Ehara and Youki Kadobayashi
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`X
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`Table of Contents
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`Traffic Engineering, QOS Routing
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`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 Valle’e—Poussz’n,
`Hugo Van Hove, Hans De Neve and Guido Petit
`On the Cost of Using MPLS for Interdomain Traflic _
`Steve Uhlig and Olivier Bonaventure
`Mechanisms for Inter—domain QOS Routing
`in Differentiated Service Networks
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`Peng Zhang and Raimo Kantola
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`QoS Measurements and Measurement Based QOS Mechanisms
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`Priority Queueing Applied to Expedited Forwarding:
`A Measurement—Based Analysis .
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`Q08/GOS Parameter Definitions and Measurement.
`inIP/ATMNetworks..._ .
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`Jorma Jormakka and Kari Heikkinen
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`QoS Assessment and Measurement for End—to—End Services .
`Torsten Bissel, Manfred Bogen, Christian Bonkowski and Dieter Strecker
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`Fairness
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`The Fairness Challenge in Computer Networks .
`Robert Denda, Albert Banchs and Wolfgang Efielsberg
`A Multi-color Marking Scheme to Achieve Fair Bandwidth Allocation .
`Kenny Pauwels, Stefaan De Cnodder and Omar Elloumi
`Traffic Phase Efiects with RED and Constant Bit Rate
`‘Lang, ' i4'§mg};¢;"z;tt;}b};;t' at at keizg} '
`UDP—Based Traffic .
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`Jiirg Diederich, Thorsten
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`Adaptive Hybrid Error Control for IP-Base
`Media Multicast Services _
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`Georg Carle, Henning Sanneck a
`Eflicient Shaping of User-Specified QOS Using Aggregate-
`Huan Ren and Kihong Park
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`Flow Control
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`Table of Contents
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`XI
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`Naoki Wakamiya, Masayu
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`Traffic Classes and Charging
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`asses in IP Networks .
`oach to Support Traffic Cl dmundo Monteiro and
`Quadros, Antonio Alves, E
`o Boavida.
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`n Framework for Pricing 111
`nts of an Ope
`t Ritter, Jochen Schille
`Hartmu
`d Billing Models for GSM and
`on of Charging an
`Evoluti
`Mobile Internet Services
`Future
`hnie, David Hutchéson an
`John Cu-9
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`312
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`I|
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`ii.
`%
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`Resource Utilization and Performance
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`Live Video Scheduling in
`Themistoklis Rapsomanikis
`proach for QOS Performance E
`Virtual Routers: A Novel Ap
`Florian Baumgartner and Torsten Br
`DSRUP: A Resou
`the Differentiated
`Joo Ghee Lim, Bmhim
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`valuation .
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`Internet Charging
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`Georg Ca/rle
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`Author Index .
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`Keynote Talk: Internet Charging .
`Andrew M. Odlyzko
`Panel: Charging for Q08 .
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`367
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`

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`Evolution of Charging and Billing Models for GSM and
`Future Mobile Internet Services
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`John Cushniel, David Hutchisonl, and Huw Oliverz
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`1 Distributed Multimedia Research Group
`Lancaster University, UK
`{j.cushr1ie,d.h}@lancaster.ac.uk
`2 Internet Research Institute
`HP Labs, 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 and all 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 3”‘ generation (2G and 3G) the
`mobile network providers have the requirement to generate revenue for
`the services they provide. To do this the mobile network providers first
`need to capture the charging and billing 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 and billing information and
`charging models for processing this data into subscriber bills are
`discussed. A selection of proposed lntemet charging models are applied
`to the mobile network market and their relative suitability is examined.
`Keywords: 1G, 2G, 3G, GSM, GPRS, UMTS, Charging, Billing, Mobile, Internet.
`
`312
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`J. Crowcroft, J. Roberts, and M. Smimov (Eds.): QoflS 2000, LNCS 1922, pp. 312-323: 2000‘
`© Springer-Verlag Berlin Heidelberg 2000
`
`
`
` 1
`introduced in 1992
`first
`The Global System for Mobile (GSM) was
`approximately 23 million subscribers, rising to over 200 million in 1999 on 0V‘'-’. .-
`
`GSM networks [1]. The aim was to provide a global mobile teleph0n6.fl9tW°’j"
`could be implemented using standard building blocks not tied to specific "-
`vendors. The uptake of GSM by subscribers is
`far higher than any _
`_
`.
`_
`predictions and typifies the 1990’s and the increasing need for personal mobi‘ .:
`
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`1“ generation (IG) GSM mobile networks provide subscribers with high ‘lug’
`";'_
`communications and low bandwidth data connections for FAX, Short "
`
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`
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`Introduction
`
`

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`
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`2 GSM Mobile Networks and the Future Internet
`
`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
`consist of a layered architecture including the mobile handsets, the telephone network
`and the subscriber invoices and bills. The Base Station and the Network Subsystems
`are often referred to as the Operational Network (ON), and is usually physically
`distributed around the area of coverage of the GSM network. The ON elements are
`often sited remotely with wide area networking (WAN) connectivity to the rest of the
`network to allow centralised remote administration of the network. The Base
`
`Evolution of Charging and Billing Models
`
`313
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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 and other 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 fiuther expand their network coverage and
`availability using the same mobile communications infiastructure. The increasing use
`of mobile telephones and devices for data communication drives the need fiom the
`market for a fast, reliable and available infrastructure. GSM proposes to 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
`GSM introduces the Universal Mobile Telecommtmication System (UMTS).
`The introduction of 2G and 3G GSM technology 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 fi'om the
`desktop Internet
`today,
`including email, secure transactions and Web browsing
`become available 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
`customers there is a requirement for the recovery ofthe infrastructure investment cost.
`This is a prime justification and motivation for charging and billing 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 and billing with GPRS will prove
`valuable when UMTS is 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.
`
`

`
`314
`
`John Cushnie et al.
`
`
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`Transmitter Stations (BTS) and the Base Station Controllers (BSC) provide the air
`interface for GSM, which is then circuit switched [5] using the industry standard SS7
`switching by the Mobile Switching Centers (MSCs) in the ON. Additional Gateway
`MSCs allow switching to other mobile and fixed line telephone networks, providing
`interconnection and roaming. Billing tickets for all calls made in the network are
`produced on the MSCs, based on subscriber Ids in the network.
`The Operational Support Systems (OSS) provides the interface to the customer
`invoices
`and bills,
`and normally includes
`systems
`for billing,
`subscriber
`administration, GSM Subscriber Identification Module (SIM) chipcard production,
`fraud detection, voicemail and off-line data-mining and analysis systems. Most
`mobile networks de—couple the ON from the OSS using Mediation Systems or
`Mediation Devices (MD). These systems are used to collect billing data fiom the ON
`and also to manage the subscriber databases in the ON elements.
`The collection of the billing data is normally via high-speed communication links
`using reliable data protocols such as File Transfer and Management (FTAM) and
`X.25. Once billing data is collected centrally it can be processed into subscriber
`invoices and bills using dedicated billing systems and the mobile network’s charging
`tariffs. The billing data can also be fiirther processed by additional data-mining
`systems to detect subscriber’s usage patterns, possible fraud detection and subscriber
`profile surveying.
`With 2G GSM the General Packet Radio Service (GPRS) [1,6,7] is introduced
`providing an overlay service for Internet access that shares the same air interface as
`1G GSM. The design goal behind GPRS is to provide high-speed Internet data
`communications for mobile devices and subscribers using the existing lG GSM air
`interface,
`thereby minimising the cost
`impact on the existing installed network
`infrastructure. GPRS is implemented in an existing GSM network with the addition of
`two new ON elements the Signalling GPRS Service Node (SGSN) and the Gateway
`GPRS Service Node (GGSN).
`Additional modifications to the existing BTS and BSC to include Packet Control
`Units are also required so that the network is GPRS aware. The two new ON elements
`provide the interface between the GSM air interface and the TCP/IP network used for
`the GPRS specific traffic, (i.e. Internet sessions used for email, http, ftp etc). GPRS
`has the advantages of digital telephony of GSM combined with increased bandwidth
`over the air interface for data traffic. The GGSN and SGSN in the ON provide the
`switching for the mobile data sessions and use packet switching [5]. GPRS data
`sessions are routed by the MSCs as for 1G GSM with the SGSN and GGSN routing
`the Internet sessions to the TCP/IP network, using packet switching [5]. Packet
`switching makes full use of the available bandwidth of the underlying network, but
`often has a reduced Quality of Service, and is suited to ‘bursty’ network traffic
`including Internet protocols such as http, ftp, email etc, where guaranteed qualities of
`service are not a top priority.
`In addition to introducing TCP/IP packet switching
`GPRS equipped mobile networks may roll in IPv6 [8] as the preferred IP protocol.
`This will allow the large number of addressable network nodes that will be required
`when there is a high saturation of mobile devices requiring Internet connectivity.
`The GGSN and SGSN produce billing tickets and statistical data relating to Internet
`traffic usage generated by GPRS calls and sessions.
`
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`2G and 3G GSM brings with 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 usage basis 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-tirne
`consumed. This shares commonality with the possibilities currently being proposed
`for Internet charging and billing. 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
`GSM architecture with the addition of UMTS specific 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].
`
`
`
`2002/3
`
`UMTS
`
`2 Mb/sec Direct lntemet connection
`
`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 GPRS and the
`associated billing issues essential for the implementation of systems for UMTS as it
`may be too late to learn when UMTS is 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 UMTS to ensure preservation of investment,
`infrastructure and knowledge.
`
`Evolution of Charging and Billing Models
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`315
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`Table 1. GSM Architecture Generations
`
`
`
`
`Max. Data Bandwidth
`
`1995
`
`SMS & Mobile Data & FAX
`
`9.6 Kb/sec Internet via Modern
`
`2001
`
`GPRS
`
`115 Kb/sec DirectInternet connection
`
`
`
`
`3
`
`Infrastructure for Charging and Billing
`
`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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`John Cushnie et al.
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`
`roaming subscribers. This usage data then needs to be processed and then set against
`the billing and charging models and tariffs in use.
`Billing tickets need to be collected and processed centrally so that the subscriber bills
`can be produced. The collection of billing tickets is ofien done by a mediation system,
`These systems may also carry out vendor specific translations on the billing ticket
`formats so that multi-vendor 0Ns can be implemented, or to allow the native billing
`tickets to be used on commercial billing 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 fonnats and standards being involved. Once all
`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 and bills for the subscribers.
`The ETSI [1] standards recommend a Charging Gateway Function (CGF) to handle
`the billing record generation. Two billing records are generated, one by the GGSN for
`the Internet part and one by the SGSN for the mobility (radio) part.
`Current GSM billing systems have difficulties implementing charging for 1G GSM
`non-voice services and it is unlikely that existing billing systems will be able to
`process the large number of new 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 connected to it. 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 gateway to Internet services and external networks:
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`Evolution of Charging and Billing Models
`
`317
`
`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 GPRS related billing tickets may be of a different format to the ones produced by
`the MSCs and may include data on the amounts of packets exchanged during GPRS
`sessions. Extensions to the mediation methods may be implemented for the collection
`and pre-processing of the GPRS related 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 UMTS specific traffic.
`Once the billing 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 needs to 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 purchase of talk time and data bandwidth in the network.
`Most mobile network operators currently offer contract subscriptions, which include a
`line rental element plus 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 UMTS existing mobile network
`subscriptions need to be extended to 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 of fraud is normally present. Mobile
`networks are no exception. The vast array of billing 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 fiaud increases and the network operators need to be aware of the
`different kinds of fraud that are possible and may occur.
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`
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`John Cushnie et al.
`
` 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 GSM systems. Below is a discussion of some of the proposed charging models,
`and how they can be adapted to the mobile network markets.
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`Metered Charging
`This pricing model is already in use with many Internet service providers (ISPs) and
`European mobile and fixed line telephone networks. The model involves charging the
`subscriber for the connection to the service provider on a monthly basis and then
`charging for metered usage of the service. The usage is usually measured in units of
`time and there is often a ‘free’ period of usage included with the monthly fee.
`Variations onthis 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 GPRS sessions open endlessly without the
`handset being powered on. Metered charging based on time for such usage may prove
`prohibitive. However, ifthe usage is based on other session parameters, for example
`number of packets transmitted/received, then the commercial impact becomes less
`and the model may be usable in mobile networks for data.
`
`Fixed Price Charging
`This pricing model is similar to that used by some US fixed line telephone networks
`for local call charging. The network service provider sets a fixed rental charge for the
`telephone connection and all local calls are then flee of charge with metered charging
`used for long-distance calls.
`The advantage of this charging model is 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 argument for using charging and billing to improve
`congestion control by dissuading subscribers from using the network through higher
`cost for the provided services.
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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 3
`proposed method of metering Internet traffic and being able to cross-charge between
`networks
`as well as
`ISP and mobile subscribers. This model
`requires
`th6
`implementation of packet counting systems in the network and complex billing
`systems that can process the packet data on a subscriber and customer basis.
`
`

`
`
`
`Expected Capacity Charging
`This charging model [9] allows the service provider to identify the amount of network
`capacity that any subscriber receives under congested conditions, agreed on a usage
`profile basis, and charge the subscriber an agreed price for that level of service. The
`subscribers are charged for their expected capacity and not the peak capacity rate of
`the network. Charging involves using a filter at the user network interface to tag
`excess traffic; this traffic is then preferentially rejected in the network in the case of
`network congestion but
`is not charged for; charges are determined by the filter
`parameters.
`This model has the advantage that the price to the subscriber is fixed and predictable
`which in turn permits the network provider to budget correctly for network usage. The
`expected capacity model also gives the network provider a more stable model of the
`long—terrn capacity planning for the network. This model fits is well with mobile
`networks and the administration of the agreed expected capacity would be done as
`part of the normal subscriber administration tasks.
`One disadvantage is that the network operator has to police the actual capacity of the
`network used by subscribers and act accordingly by limiting the subscribers service to
`what has been purchased, or by invoicing the subscriber for the extra capacity used,
`on a metered tariff for example.
`
`Evolution of Charging and Billing Models
`
`319
`
`The advantage of this method of charging is that the absolute usage of the network
`and services can be metered, calculated and billed for very accurately, as long as the
`packet information can be captured efficiently.
`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 network traffic 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.
`
`Edge Pricing
`Proposed in [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 and alert the network operators to such
`congestion.
`This approach has the advantage that all session data can be captured locally and does
`not involve exchanging billing 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 and the costs of that traffic to both networks. The cost of coll