P920D4.doc

Project Report

UMTS Network Aspects

VHE Trial review report

Editor: Giuseppe Geuna, Telecom Italia - CSELT

Suggested readersService orientated readers who are interested in the provision of the Virtual Home Environment (VHE), and network designers who have responsibility for IP implementations.

EDIN 0082-0920

Project P920

For full publication

January 2001

Abstract

The transition towards an All-IP network implementation for 3GPP Release ‘00 has been a key motivator and enabler for a Virtual Home Environment (VHE) trial. This deliverable describes the trial objectives – to produce a realistic VHE from the user’s perspective, and it evaluates the results of a series of test cases.

EURESCOM PARTICIPANTS in Project P920 are:

Elisa Communications Corporation

British Telecommunications plc

T-Nova Deutsche Telekom Innovationsgesellschaft mbH

France Télécom

Telenor AS

Telecom Italia S.p.A.

Hellenic Telecommunications Organization S.A.

Telefónica S.A.

Project P920 “UMTS Network Aspects”

VHE Trial review report

Editor: Giuseppe Geuna, CSELT

Project leader: Geoff Richman, BT

Project supervisor: Uwe Herzog, EURESCOM GmbH

EURESCOM published project result; EDIN 0082-0920

ã 2001 EURESCOM Participants in Project P920

Disclaimer

This document contains material which is the copyright of certain EURESCOM PARTICIPANTS, and may not be reproduced or copied without permission.

All PARTICIPANTS have agreed to full publication of this document.

The commercial use of any information contained in this document may require a license from the proprietor of that information.

Neither the PARTICIPANTS nor EURESCOM warrant that the information contained in the report is capable of use, or that use of the information is free from risk, and accept no liability for loss or damage suffered by any person using this information.

This document has been approved by the EURESCOM Board of Governors for distribution to all EURESCOM Shareholders.

VHE Trial review report page 1 (19)

Preface

UMTS is the third generation mobile communications system which will integrate multimedia communications for the mass market both in the fixed and mobile arena. A key capability, known as Virtual Home Environment (VHE), promises to provide users with a common look and feel of the service, regardless of location, network and terminal type. Currently there is a lot of development work occurring in the standards bodies on UMTS, e.g. in 3GPP, ETSI, ITU-T, IETF and the ATM-forum. It is apparent that UMTS Release’99 will not provide the true roaming of VHE across heterogeneous networks as envisaged.

The project P920 is investigating and identifying existing mechanisms that could be used to support VHE across multi-networks and over many different access types to many different terminals, adapting service delivery according to their capabilities. Key points of the project are:

Identification of the candidate technologies.

Development of architecture and services for global mobility, based on heterogeneous local access networks.

Running a trial, showing the operation of VHE across fixed and mobile networks.

The main driver behind this is the demand for new services (mobile Web browsing, push technologies for voice, graphics, interactive email, m-commerce, audio and video-conferencing, video distribution etc.).

The project started in February 1999 and ended in December 2000. It was fully funded with an overall budget of 200 MM. The participants in the project were AF, BT, DT, FT, IT, NT, OG and TE. The project was led by Mr. Geoff Richman (BT) after having been taken over from Billy Johnston in April 2000.

This is the fourth and last deliverable of the project.

The transition towards an All-IP network implementation for 3GPP Release 2000 has been a key motivator and enabler for a VHE trial. This deliverable describes the trial objectives – to produce a realistic VHE from the user’s perspective and to evaluate the results of a series of test cases.

The VHE trial focuses mainly on:

User service capabilities required for the VHE trial;

Trial configurations that form the trial topology;

Test cases that validate the trial requirements;

Evaluation of the trial results;

Recommended enhancements for a further VHE trial.

The results are contained in this deliverable, which is publicly available on the EURESCOM Web server (www.eurescom.de).

Uwe Herzog,

EURESCOM project supervisor

ã 2001 EURESCOM Participants in Project P920 EDIN 0082-0920

page 2 (19) VHE Trial review report

Executive Summary

This deliverable is of particular interest to service orientated readers who are interested in the provision of the virtual home environment and network designers who have responsibility for IP implementations. A Web-based HTML implementation of the VHE was used as the basis of the user’s portal for the trial.

This deliverable describes the trial objectives – to produce a realistic VHE from the user’s perspective and to evaluate the results of a series of test cases.

The VHE trial focuses mainly on:

User service capabilities required for the VHE trial;

Trial configurations that form the trial topology;

Test cases that validate the trial requirements;

Evaluation of the trial results;

Recommended enhancements for a further VHE trial.

The P920 VHE trial was implemented, and the evaluation of the results led to the following conclusions: The Virtual Home Environment is a feasible concept with the users accessing their ‘own’ environment from different networks or terminals and users roaming between different IP subnets. Manual user registration and authentication was used for a multi-user multimedia service domain. The trial did not support bandwidth negotiation/renegotiation with the network and terminal and P920 suggests that this feature combined with application adaptation should be included in a future trial. Also, no meaningful performance assessment was possible because of the use of the public Internet in the trial. A managed network may be required if performance metrics were included in a future trial.

Nevertheless, P920 undertook a successful VHE trial involving collaboration between eight EURESCOM partners, an HTML VHE portal and a wide range of services including media conversion supported by an IP infrastructure.

EDIN 0082-0920 ã 2001 EURESCOM Participants in Project P920


List of Authors

Oscar Mezquita

Luis Jordan de Urries

Raquel Garcia Perez

Lionel Morand

Emmanuel Tzanettis

Sivert Sorumgard

Anastasia Kaltabani

Miltos Anagnostou

Erik Lillevold

Delphine Plasse

Darren Pratt

Geoff Richman

Serge Tessier

Giuseppe Geuna

Ivano Costa

Antti Leino



Table of Contents

Preface.................................................................................................................................................................1Executive Summary.............................................................................................................................................2List of Authors.....................................................................................................................................................3Table of Contents................................................................................................................................................4Abbreviations......................................................................................................................................................51 Introduction.................................................................................................................................................62 VHE Trial Description................................................................................................................................8

2.1 Overview.............................................................................................................................................82.2 Infrastructure.......................................................................................................................................9

3 VHE Trial Implementation........................................................................................................................113.1 Test Specifications.............................................................................................................................113.2 Results...............................................................................................................................................13

4 VHE Trial Evaluation................................................................................................................................164.1 Success Points...................................................................................................................................164.2 Limitation points...............................................................................................................................164.3 Comparison with initial goals............................................................................................................164.4 Recommendations for future VHE trials...........................................................................................17

5 Conclusions...............................................................................................................................................186 References.................................................................................................................................................19



Abbreviations

CS Circuit switchedCoA: Care of AddressFA Foreign AgentHA Home AgentHTML HyperText Mark-up LanguageID IdentityIP Internet ProtocolLAN Local Area NetworkMGCF Media Gateways Control FunctionMGW Media GatewayMN: Mobile NodeMS Mobile StationPC Personal ComputerPDA Personal Digital AssistantPIN Personal Identification NumberPSTN Public Switched Telephone NetworkRFC Request for CommentsUMTS Universal Mobile Telecommunication System VHE Virtual Home EnvironmentW-CDMA Wideband Code Division Multiple AccessWLAN Wireless LAN3GPP 3rd Generation Partnership Project



1 Introduction

The purpose of the Virtual Home Environment (VHE) trial is to demonstrate the feasibility of roaming and the support of remote access for VHE. A brief description of the demonstration software, a basic implementation of the UMTS Virtual Home Environment concept, is included to help the reader’s understanding of the trial [1]. The VHE system for the trial provides a web based interface that is constructed dynamically based upon user location and any relevant customer profile information stored within the system. The trial uses an experimental UMTS system located in the Italian network and W-LAN subnets in the German network. The internet address allocation for the roaming user is handled by Mobile IP using a UMTS network address that is provided to the roaming terminal equipped with Foreign Agent functionality.

A WEB browser provides access the VHE server via the system login screen, as shown in Figure 1, prompting you for your user ID and PIN.

Figure 1: VHE login screen

Following the correct entry of Customer Number (User ID) and PIN, a welcome screen appears which displays information relevant to the User’s location e.g. Home/Office/Mobile Network.

The IP Address of the terminal is recorded when logging on to the VHE system. This enables retrieval of the User’s current IP Address by another network via the media gateway. Further services may now be selected by clicking on the icon or text, depending on whether graphics are enabled, in the bottom frame.

The welcome screen of the VHE service is shown in Figure 2 and is presented after login displaying details of the User’s current location, network speed and links to the User’s personalised services.



Figure 2: VHE Server Main Page

Several basic services have been provided for access via the VHE system:

News: The news service allows the user to choose news articles and language.

Find: This service allows a user to find other user’s contact or location details.

Shares: The shares service allows the user to request shares from the FTSE 100.

TV: The TV application demonstrates video streaming

Papers: This service displays a summary of today’s UK newspapers.

Video-Call: This service allows the user to place a NetMeeting call to another user.

A network configuration database contains mapping information between the physical access and the domain name e.g. Home/Office/Mobile. User’s applications are delivered according to the transmission and terminal characteristics of these domains.

The VHE trial was set-up to evaluate the User access to VHE services in different domains in the DT and IT networks as described in the following chapters. The implications of restrictions imposed on the terminal configuration and network infrastructure are addressed in the chapters concerning the test specification for the trial.



2 VHE Trial Description

2.1 Overview

The purpose of the VHE trial is to implement services and applications scenarios that illustrate some of the key features of UMTS and of the VHE [2]. A number of trials have been performed, whose objectives can be defined as follows:

A user interface that is personalised to a user;

A user interface that exhibits a similar “look and feel” to the service irrespective of a user’s location or terminal type;

User access to his or her own VHE from a laptop, PCs or PDA while roaming in a foreign network;

User access from a desktop computer in his or her home network;

The ability to transfer VHE services across networks, so that the same user personalised services are available wherever a user has roamed to, as a prime objective of the trial.

In the trial it was assumed that the VHE environment is IP-based [3].

The general features of the services submitted to trials are referred to as trial service features, which will actually provide the user with an experience of VHE. They are listed herewith:

a) A flexible user interface: to register, subscribe to services, to customise the access database and to display subscribed applications;

b) Customisation of applications: Customisation based on customer’s identity;

c) User access to real-time and non real-time multimedia applications;

d) A VHE server: to associate users and services to their terminal capabilities and network throughputs;

e) Application adaptation to terminal capabilities;

f) Application adaptation to different network throughputs;

g) Geographic distribution of: two home networks one in Germany and one 3G access in Italy, and two foreign networks i.e. two sub LANs in Germany;

h) One VHE server in Heidelberg;

i) Media Gateways (as introduced in the 3GPP R’00 architecture model) to support media conversion.

The general scenarios of the services submitted to trials are referred to as trial service scenarios and are described below:

1. Mobility within subnets of the DT network

Each user of the trial has a unique user identifier (ID & PIN). The VHE server associates to that identifier a user’s profile, such as subscribed services and “ language spoken”. A Mobile IP enabled laptop roams from one sub-net to another sub-net within the DT network. Mobile IP handles the handover between base stations. We can then demonstrate continuity of service with minimum degradation.

2. Adaptation to different network characteristics



We apply some bandwidth differentiation between the DT sub-nets. Therefore, when the laptop changes sub-net, the VHE server adapts the application content to the user’s preferred language, to the terminal capabilities and to the sub-net throughput.

3. Use of Media Gateways

A user is registered at a UMTS terminal that only supports telephony (speech). To deliver an email to his terminal, the email has to be transformed appropriately. A media gateway will receive the entire e-mail, and perform a text-to-speech conversion (instead of e-mail, fax could be considered).

2.2 Infrastructure

The networks involved in the trial were provided by DT and IT.

BT provided the VHE user interface, the VHE server and access database containing customers profile information, customer service preferences, location registers, terminal capabilities and sub-network throughputs information. The VHE server was accessible via a customisable user interface, from any HTML browsers enabled terminals.

DT provided the Mobile IP core infrastructure i.e. mobility agents (HA, FA), mobile nodes (MN), Care-of-Address (CoA):

IT had a UMTS R’99 W-CDMA radio simulator test-bed. It offered a packet switched (IP) and circuit switched (CS) connections to the Wide Area Network

As for the terminals involved, the following were used:

HTML browser-enabled terminals

Laptops with Mobile IP stack and Wireless LAN access

Mobile Laptops with H.323 software installed. MS NetMeeting was used as the application software to realise H.323

Figure 3 highlights the trial architecture showing the whole scheme with the 3 networks connected via IP routers.

The VHE trial actually consisted of two different IP-based networks and one UMTS R’99 test-bed owned by different operators – BT, DT and IT-CSELT respectively. All three networks were connected via the public Internet.

Subnet 3

Foreign Network'office network'

Subnet 1 Subnet 2

Internet

Home Network'home network'

Foreign Network'mobile network'

Access Point Access Point

VHE ServerDatabase

PSTN

Calling party

Access PointForeign Agent

Foreign AgentHome Agent

Mobile Node /VHE User 1

Media GatewayIT UTRAN

Access NetworkMobile Node /VHE User 2

Figure 3: Overall trial architecture



In the trial, three basic functionalities were identified: Mobile IP, VHE Server and Media Gateways.

Mobile IP was used so as to enable a terminal to change its point-of-attachment to the network without losing incoming communication. The VHE Server, on the other hand, is necessary for user registration, authentication and for VHE service provision. The VHE Server also provided the content for two services: a News Page service (non-real time multimedia service) and a Video-service (multimedia service).

The trial scenarios employed Media Gateway conversion technology to adapt Group-3 Faxes or RFC822 e-mails to H.323 streams which could be supported by “off-the-shelf” IP-T clients (e.g. MS NetMeeting). Examples of Media Gateway conversion are:

Fax Text Audio(G.711) H.323

E-mail Audio(G.711) H.323

Only Audio to H.323 was used in the trial.

Interfaces between the different network elements:

Media Gateway / VHE Server (for the exchange of the service descriptors)

VHE Server / Mobile IP Home and Foreign Agents (for the VHE database needing to be kept informed about the location of the user)

VHE Server / UMTS IP router (for passing suitable parameters when the mobile terminal moves to a different subnet).



3 VHE Trial Implementation

3.1 Test Specifications

This chapter describes the test specifications, namely the test configurations, use cases, and test suites for actually identifying the test cases for the trial. Completed templates highlighting the several DT and IT test cases are reported.

The test configuration, is a description of the setting in which the test is to be carried out. Three test configurations were selected as described below:

Table 1: Configuration 1 - Access from DT Wireless LAN Network

User Location The user is located in one of the DT Wireless LAN subnet.Terminal Set-up Laptop PC with Mobile IP enabled. Client software is a HTML-enabled

browser and/or MS NetMeeting. Network and Protocol Wireless LAN network, HTTP/TCP/MIP. Mobility Management Handled by Mobile IP, supports FA care-of address only.

Table 2: Configuration 2 - Roaming among DT WLAN Subnets

User Location The user is located in one Wireless LAN subnet, and roams into the other. Terminal Set-up Laptop PC with Mobile IP enabled. Client software is a HTML-enabled

browser and MS NetMeeting.Network and Protocol Wireless LAN network, HTTP/TCP/MIP. Mobility Management Handled by Mobile IP, supports FA care-of address only.

Table 3: Configuration 3 - Access from IT Network

User Location The user is located in the IT network implementing the UMTS experimental system.

Terminal Set-up Desktop PC with Windows NT 4.0. HTML-enabled browser and MS NetMeeting.

Network and Protocol UMTS experimental system, HTTP/TCP/IP. Mobility Management Fixed address allocation scheme, DHCP not supported.

The use cases describe what the user should do or try to do: access to news service, access to video (streams) service, access to incoming phone calls, (profile) modification, access to video call service.

The test suites describe what is to be observed in the trial. The general test suite structure (table 4) and the description of the actual test suites (table 5) follow:

Table 4 - Structure of the test suites

Root Category Aspect Variant IDVHE support VHE

Portability PORNetwork NET

Static STARoaming ROA

Terminal TERLaptop PC LPCDesktop PC DPCPDA PDA

Personalization PERModify profile MOD

Authentication AUT



Root Category Aspect Variant IDNetwork NETTerminal TERUser interface UI

Table 5 - Description of test suites.

ID DescriptionVHE Verify whether the VHE aspects that are implemented function properly, from

the user’s perspective. VHE/POR Portability aspects, i.e., a service should be accessible from different locations

and terminals. The services should also adapt themselves correspondingly. VHE/POR/NET Network portability, i.e., a service should be accessible from different

networks. The services should adapt themselves to the network. VHE/POR/NET/STA Static network portability aspects, verifying that a service can be accessed

form various networks without maintaining a session while changing network. VHE/POR/NET/ROA Roaming network portability, i.e. the same as above, but with the additional

requirement that an open connection and session should be maintained while the terminal is changing network.

VHE/POR/TER Terminal portability, i.e., a service can be accessed from different terminals. The services should adapt themselves properly to the current terminal.

VHE/POR/TER/LPC Verify that the service may be accessed properly from a laptop PC. VHE/POR/TER/DPC Verify that the service may be accessed properly from a desktop PC. VHE/POR/TER/PDA Verify that the service may be accessed properly from a Personal Digital

Assistant (PDA). VHE/PER Personalization of services, i.e., it should be possible for the user to configure

the service as he likes. VHE/PER/MOD The user should be able to modify the current user profile. VHE/PER/MOD/AUT A mechanism should exist to enable the user to authenticate so that the

corresponding profile may be obtained and modified. VHE/PER/MOD/NET The user should be able to modify the characteristics of the networks he may

use to access the service. Parameters like throughput may be modified. VHE/PER/MOD/TER The user should be able to modify the description of the capabilities of the

terminal(s) he uses to access the service. Parameters may be e.g. media support (HTML or H.323).

VHE/PER/MOD/UI The user should be able to modify the user interface preferences like e.g. language.

Test cases are combinations of configurations, use cases and test suites, and actually identify the individual tests of the trial. The test cases undertaken by DT and IT are listed in Table 6.

Table 6 - Combination of configurations, use cases and test suites for defining test cases.

Configuration Use case Test suites Test case ID Test type

1. DT/W-LAN

1. NewsVHE/POR/NET/STA, VHE/POR/TER/LPC

1-1-1 Functional

2. VideoVHE/POR/NET/STA, VHE/POR/TER/LPC

1-2-1 Functional

3. PhoneVHE/POR/NET/STA, VHE/POR/TER/LPC

1-3-1 Functional

4. ModVHE/PER/MOD/AUT, VHE/POR/NET/STA

1-4-1 Functional

5. ModVHE/PER/MOD/TER, VHE/POR/NET/STA

1-4-2 Functional



Configuration Use case Test suites Test case ID Test type

2. DT roaming

1. NewsVHE/POR/NET/ROA, VHE/POR/TER/LPC

2-1-1 Functional

2. VideoVHE/POR/NET/ROA, VHE/POR/TER/LPC

2-2-1 Functional

3. PhoneVHE/POR/NET/ROA, VHE/POR/TER/LPC

2-3-1 Functional

3. Access from IT

1. NewsVHE/POR/NET/ROA, VHE/POR/TER/LPC

3-1-1 Functional

2. VideoVHE/POR/NET/ROA, VHE/POR/TER/LPC

3-2-1 Functional

3. Video Call

VHE/POR/NET/ROA, VHE/POR/TER/LPC

3-3-1 Functional

This heterogeneous non-exhaustive choice aims to present the diversity of the tests achieved and to reflect the wide configuration spectrum encompassed during our trial. Test cases only verified that the service can be accessed properly from a laptop PC was carried out. However, results apply also to desktop and PDA terminal access.

3.2 Results

All test cases in Table 6 were implemented with success and the results recorded. Table 7 is an example of how these results were tabulated.

Table 7: Test Case 2-1-1 (see definition in Table 6)

Identifier 2-1-1

Test type Functional

Configuration 2. Roaming between DT Subnets

Use case 1. Accessing the News Page Service

Test suites VHE/POR/NET/ROA, VHE/POR/TER/LPC

Version 1.0

Change log Date Initials Comment

13/09/00 08/09/00 Two wireless cells overlap slightly. Networks involved are Home and Mobile.

Purpose Observe how a News Page Service session (HTTP request/reply) is effected when roaming from one W-LAN subnet to another within DT. The roaming/handover is based on MobileIP.

Rationale VHE services should work continuously when mobile terminals are on move in and between wireless networks.

Set-up The user is located in the ‚Home Network‘ subnet, which is also the Mobile IP Home Network. The terminal is a laptop PC with Mobile IP enabled. Client software is a HTML-enabled browser. During a session, the user moves with his terminal from one wireless cell towards another and back n‘ forth.

Description The user starts and uses the News Service as in 1-1-1. In the middle of the downloading of a relatively huge HTML page, the laptop is moved



between the two W-LAN subnets.

Test procedure First, do the test case 1-1-1 and notice the test results for the actual HTML page. Download the same page again while moving the laptop from one W-LAN to the other. Compare the results with the previous ones. If practicable, the functionality of Mobile IP should be registered, i.e. the care-of-address.

Test results Time usage: 3 min. (irrelevant)

Bandwidth: 500kbps (WLAN) / 11Mbps (WLAN)

Content validity: Ok

Presentation quality: Ok

Overall judgement: Ok; See notes below.

Notes There is no ‘huge HTML news page’ so the transfer is not affected by the handoff because it is already finished when the roaming movement occurs

Reported failure: Let assume that the user has subscribed the news page service in his originated network. The user accesses news pages, then roams towards a second, visited network. The user can still read news pages even if it is not subscribed to services in the visited network.

Table 8 reports a synoptic overview of all the test cases in the trial.

Table 8: Reported Test Case Results

Configuration RequirementTest case

IDTest description Test result

DT/W-LAN

Static network portability aspects, verifying that a service can be accessed form various networks without maintaining a session while changing network.

1-1-1News

The user accesses the “your news” service and retrieves the page with text and images that are displayed in the browser.

The user is able to correctly download a news page with text and images from both home network and from a foreign network.

1-2-1Video

The user accesses the video service. The VHE server sets up a ‘video stream’ to the client who in order to view it launches Microsoft media player.

The user is able to connect and correctly display the video stream. Quality of video is dependant on network congestion but not dependant on network type.

1-3-1Phone

The user is informed about an incoming phone call. The media GW converts the PSTN audio to H.323 audio. An end-to-end connection is established between the media GW and the terminal, and an audio stream is played by Microsoft NetMeeting.

The user is able to listen to the audio message at quality comparable to fixed analogue lines.

A mechanism should exist to enable the user to authenticate himself so that the corresponding profile can be found and modified.

The user should be able to modify the user profile in order to use the applications which are appropriate for the characteristics of the networks.

1-4-1Profile

modification

The user wants to authenticate himself in order to change the identification parameters. He accesses the VHE server. Forms and scripts enable the changing of PIN code.

The identification parameters are changed. The new PIN parameters are applied in the succeeding logins.

1-4-2Profile

modification

The user wants to change terminal settings stored in the user profile. He logs onto the VHE server. Forms and scripts enable updating the terminal settings, e.g. disabling graphical contents.

The laptop terminal settings are correctly changed upon the user request. Services apply the terminal settings when the service is adapted to the user.

DT roaming in DT subnets.

Roaming network portability aspects, verifying that a service can be accessed form various networks maintaining a session

2-1-1News

The user starts to use the news service as in 1-1-1. In the middle of downloading the laptop is moved between the two WLAN

The connection is maintained between changing networks, but it was not verified whether the



Configuration RequirementTest case

IDTest description Test result

while changing network.

The user should be able to modify the user profile in order to use the applications which are appropriate for the characteristics of the networks. -

subnets.

file transfer works during the movement because the file had already been transferred.

2-2-1Video

The user starts to use the video streaming as in 1-2-1. In the middle of the video stream transfer the laptop is moved between the two WLAN subnets.

The nature of the ‘streaming video’ is not suited at all for handover. It is namely still the same file that is played, so the same quality, even if the network characteristics have changed (improved).

The user has subscribed the video streaming service in his originated network. The user accesses video streaming, then roams towards a second, visited network. The user can still see video streaming even if it is not a service subscribed in the visited network.

2-3-1Phone

The user starts and uses the media gateway voice-to-H.323 service as in 1-3-1. In the middle of the audio stream output, the laptop is moved between the two W-LAN subnets.

Very robust solution. The connection is still active even after a non seamless handover (cut off time approximately 1 minute).

Access from ITThe user should be able to modify the user interface preferences e.g. language.

3-1-1News

The user accesses the news service. The client connects to the VHE server and retrieves an HTML page with text and images that are displayed in the browser.

The user is able to correctly download a news page with text and images.

3-2-1Video

The user accesses the video service. The client connects to the VHE server and receives a video stream.

The user is correctly able to view video from the VHE server. The quality of the video was acceptable.

3-3-1VideoCall

The IT user connects to the VHE server and activates the video call service. He makes a call to another user who is also at the same moment logged to the VHE system

The user is able to use the video service to establish a real time video conference call. The quality of the video during the call was acceptable.



4 VHE Trial Evaluation

4.1 Success Points

VHE is definitely a feasible concept which is demonstrated by the fact that all the test cases that were carried out have basically succeeded.

Roaming between subnets refers to an important VHE feature that was performed in the DT network. The connection to VHE was not interrupted while roaming.

Session portability between networks was carried out as well, as the initiated session actually continued after hand-off.

VHE with manual user identification and authentication addresses the issue of accessing the VHE services in a secure way. This was performed on a manual basis for the time being due to the present configuration of VHE server.

Multimedia and multi-user support is demonstrated by the media (call, video call, images) and by the number of users deployed in the test cases that were carried out.

Service portability between networks refers to the fact that it was possible to access the same services from different networks.

Service portability across terminals refers to the fact that it was possible to access VHE from different terminals.

4.2 Limitation points

Dynamic Service adaptation was not supported by VHE server implementation, as manual interventions were actually required while performing the test cases.

Trial Adjustment to meet available resources was necessary sometimes for being allowed to carry out the test cases.

No performance tests were performed, as any assessment on the results was basically reached on a qualitative basis.

No change was made to service based on terminal capabilities, due to the present VHE implementation.

4.3 Comparison with initial goals

In this chapter, ten trial objectives and their related conformance to requirements are presented.

1. A user interface that is personalised to a user.All required actions including registering, subscribing to services and displaying subscribed applications were completed. The characteristics of the modification interface (options interface in BT VHE) meets probable user expectations. The user may expect to be able to customise the graphical look of the interface and to have the similar look everywhere. This could be a possible test case in future trials.

2. A user interface that exhibits a similar “look and feel” to the service irrespective of a user’s location or terminal types.

A consistent user interface was presented when roaming between DT subnets and to the IT 3G mobile network. Further investigation is still required on how the VHE server recognizes and responds to different terminal capabilities. At the moment however, the HTML-based browser is the only reasonable choice for a trial terminal. The addition of a WAP-capable terminal to the test set-up could be considered for future trials.

3. Customisation of applications: Customisation based on user’s identity.



The static customisation (e.g. global disabling of graphics) was verified to work correctly.

4. Customisation of applications: Adaptation based on availability of Network Resources

The dynamic adaptation of e.g. video stream to changing network capabilities needs further investigation

5. User access to real-time and non real time multimedia applications.Access to both types of applications was verified to work correctly. Both types of applications performed at the same or better level that the user is accustomed to when using similar services on the Internet.

6. A VHE server: to associate users and services to their terminal capabilities and network throughputs.

The VHE server does not correctly adapt video streaming if the network throughput changes. If the network throughput changes, the stream has to be adjusted dynamically.

7. Application adaptation to terminal capabilities and different network throughputs.

The applications used were standard multimedia applications which do not have built in capability to sense the network characteristics or receive them from the VHE server. Therefore the applications themselves were not adapting.

8. Geographic distribution of: two home networks one in Germany and one 3G access in Italy, and two foreign networks i.e. two sub LANs in Germany.

The network used in the trial was routed over public Internet to the different geographic locations. The effect of internet congestion to trial application performance was noted but should be examined in more detail in the future trials.

9. One VHE server in Heidelberg.The access to VHE server worked correctly for all network types. Roaming to other network did not affect the registration at VHE Server. The server correctly used different encoded video files for different networks.

10. Media Gateways (as introduced in the 3GPP R00 architecture model) to support media conversion.

The media gateway capabilities were tested in several test cases and verified to work correctly. Media transformations were completed without penalties in performance and the media gateway was not a bottleneck in any of the tests which used it.

4.4 Recommendations for future VHE trials

There were many configurations and test components that were originally envisaged for the trial but for a number of reasons were not covered in the present test cases. Examples include roaming of a laptop terminal to a foreign network through the use of suitable foreign agents (actually DT terminal in IT network), user profile updating and QoS renegotiation to take account of different transmission bandwidth.

In addition, new trial aspects can be explored in both testing available infrastructures and refining or widening services. An example of the former is to compare the performance with and without Internet connection, i.e. one subnetwork should be directly connected to the VHE server. An example of the latter is service continuity over different terminals i.e. a user arrives at home and transfers an active call from his/her GPRS/UMTS terminal to a desktop PC or PDA.

Other trial possibilities can be identified in view of the extremely dynamic and ever evolving telecommunications market. A GPRS network would have provided added value to the experiment (features, additional delay, lower bit-rates, etc.). The use of a UTRAN emulated access network may provide further insight on the differences between a high-speed fixed IP network and another one which is mobile.





5 Conclusions

There were a number of objectives that were set when planning the VHE trial. To varying extents, these objectives were met, the only burdens being the unavailability of actual UMTS technology, particularly in the Core Network and the mandatory utilization of Internet which did not allow real time broadband services to be demonstrated in their full capacity.

The most interesting conclusion of the trial is related to the feasibility of the VHE concept. The trial showed that the Virtual Home Environment is a feasible concept with the users accessing their ‘own’ environment from different networks or terminals and users roaming between different IP subnets. In a fully implemented UMTS network, VHE is expected to encourage network utilization since it distinguishes the manner in which the user uses the network and services from the very “user annoying” aspects like network complexity, diversity of offered services and terminals in different networks, user and network locations etc.

Another result of the trial is the successful utilization of an experimental UMTS access network for accessing VHE. Once UMTS is readily available on the market, VHE features, similar to those used in the VHE trial, will receive wider application.

Proposals have been made on new trial aspects that could be explored in both testing available infrastructures and refining or widening services. These cover QoS negotiation, increased range of terminal types and use of 3GPP R’00 network implementation. The trial did not support bandwidth negotiation/renegotiation with the network and terminal and P920 suggests that this feature combined with application adaptation should be included in a future trial.

Nevertheless, several aspects of VHE are still to be confirmed as depicted in the main text and future VHE trials are essential if carried out without the constraints imposed on the present trial. This is important particularly in those aspects where the present trial gave poor results e.g. service adaptation, performance testing, QoS etc and in aspects related to the minimization of external factors that had impact on the trial e.g. better resource availability, real UMTS access and core networks etc.

Finally, P920 undertook a successful VHE trial involving collaboration between eight EURESCOM partners, an HTML VHE portal and a wide range of services including media conversion supported by an IP infrastructure.



6 References

[1] “The Virtual Home Environment: Architectures and Trials” Antonella Napolitano, Geoff Richman, IST Mobile Summit, Galway, 1-4 October 2000.

[2] P920 Deliverable 1: VHE concept description, scenarios and protocols.

[3] P920 Deliverable 2: Requirements, Architecture and Protocol Enhancements for Mobility Management, Call Control and VHE in UMTS Core Networks.

[4] P920 Deliverable 3: Guidelines for the development of the future UMTS architectures.


Documents

P920D4.doc