Deliverable 2.2 - the School of Engineering and Design - Brunel ...

IST Project 

PLUTO – Deliverable 2.2 

Contract no.: 

026902 

Prototype Network Selection and 

Handover Algorithms 

Project Number: 026902 

Project title: 

PLUTO 

Deliverable Type: 

Report 

CEC Deliverable Number: IST-026902/LeadPartner/WP02/RE/R/Del2-2 

Contractual Delivery Date: December 2006 

Actual Delivery Date: 10 th January 2006 

Title of the Deliverable: Prototype Network Selection and Handover Algorithms 

Workpackage: 

Service Scenario and System Specification - WP2 

Nature of the Deliverable: Report 

Organisations: 

1 Brunel University Brunel 

2 Broadreach Systems Ltd 

3 Dibcom SA 

4 Deuthches Zentrum Fuer Luft und Raumfahrt E.V. 

5 Digital TV Group 

6 SIRADEL 

7 Tampere University of Technology 

8 Telediffusion De France 

10 Ortikon Interactive Ltd 

Authors: 

Adrian Hornsby, Irek Defee, Mikko Oksanen, Tom Owens 

Circulation List: 

Partners 

Keywords: 

Discovery 

DVB, Digital Television, Diversity, Network, Handover, 

tt.01.07 1

IST Project 


Contract no.: 

026902 



Version Control 

Change Log Version Date 

Template 19/10/2006 

Draft 15/12/2006 

Final version 1.00 10/01/2007 

tt.01.07 2

IST Project 


Contract no.: 

026902 



Contents 

1 INTRODUCTION .......................................................................................................................................7 

1.1 MULTICAST & BROADCAST...................................................................................................................7 

1.2 REVIEW OF BROADCAST NETWORKS .....................................................................................................8 

1.3 REVIEW OF NETWORK AND SERVICE DISCOVERY TECHNOLOGIES ........................................................10 

1.3.1 DVB-T/H networks..........................................................................................................................10 

1.3.2 DMB/DAB.......................................................................................................................................14 

1.3.3 MBMS .............................................................................................................................................15 

1.3.4 MediaFlo ........................................................................................................................................16 

1.4 NETWORK AND SERVICE DISCOVERY PROBLEMS.................................................................................17 

1.5 HANDOVER PROBLEMS ........................................................................................................................18 

2 NETWORK AND SERVICE DISCOVERY IN MOBILE BROADCAST SYSTEMS.......................19 

2.1 IMPROVING NETWORK & SERVICE DISCOVERY FOR BROADCAST NETWORK ......................................19 

2.1.1 Position Assisted Discovery System................................................................................................19 

2.1.2 Universal Network and Service Discovery .....................................................................................20 

3 HORIZONTAL HANDOVER IN BROADCAST NETWORKS..........................................................25 

3.1 SCENARIO FOR HORIZONTAL HANDOVER IN DVB-H NETWORK...........................................................25 

3.1.1 REVIEW OF THE STATE OF THE ART ......................................................................................................26 

3.1.2 OPTIMIZATION FOR HORIZONTAL HANDOVER ALGORITHMS.................................................................28 

4 VERTICAL HANDOVER IN BROADCAST NETWORKS ................................................................29 

4.1 SCENARIO AND TAXONOMY FOR VERTICAL HANDOVER .......................................................................30 

4.2 VERTICAL HANDOVER EXECUTION LAYER ...........................................................................................34 

4.3 REVIEW OF THE STATE OF THE ART FOR VERTICAL HANDOVER ............................................................35 

4.4 FACTORS FOR A VERTICAL HANDOVER DECISION.................................................................................35 

4.5 DECISION ALGORITHMS .......................................................................................................................36 

4.6 NETWORK MONITORING ALGORITHM..................................................................................................38 

5 INTEGRATED SYSTEM FOR THE NETWORK SELECTION AND HANDOVER IN 

HETEROGENEOUS WIRELESS NETWORK..............................................................................................39 

6 PROTOTYPE APPLICATION................................................................................................................44 

7 CONCLUSION ..........................................................................................................................................46 

8 REFERENCES ..........................................................................................................................................46 

8.1 OTHER REFERENCES ............................................................................................................................48 

tt.01.07 3

IST Project 


Contract no.: 

026902 



Figure Captions 

Fig. 1. Multicast vs Broadcast mode 

Fig. 2. Wi-Fi standards and specifications 

Fig. 3. Comparison of the main broadcast technologies 

Fig. 4. Network Discovery for DVB-H 

Fig. 5. The grouping of TV-Anytime metadata 

Fig. 6. ESG Structure 

Fig. 7. MBMS service metadata fragments 

Fig. 8. Service Discovery Problems 

Fig. 9. Localisation and Coverage Estimation TUT (Finland) DVB-H Transmitter 

Fig. 10. Universal Network & Service Directory 

Fig. 11. Discovery Agent for Universal Network & Service Directory 

Fig. 12. New UNSD model based on ESG 

Fig. 13. UNSD: ESG with extended NetworkAreaTable and new NetworkSubscriptionTable 

Fig. 14. Proposed Extension to Network Area Information Fragment 

Fig. 15. Extension to NetworkCell element 

Fig. 16. Proposed Network Subscription Fragment 

Fig. 17. Proposed Network Subscription Channel Fragment 

Fig. 18. New NetworkRef element in the Service fragment 

Fig. 19. New structure of the proposed UNSD 

Fig. 20. Future Mobile Broadcast Network 

Fig. 21. The prefect vertical handover scenario 

Fig. 22. Fully managed broadcast network 

Fig. 23. Unmanaged broadcast networks system 

Fig. 24. Functions to Support Handover in Broadcast Network 

Fig. 25. Wi-Fi as DVB-H gap filler 

Fig. 26. Different network environments 

Fig. 27. Network parameters evaluation 

Fig. 28. Terminal Architecture to Support Heterogeneous Network Selection 

Fig. 29. Network and Services Discovery Architecture 

Fig. 30. User Profiles & Preferences 

Fig. 31. Terminal & Application Requirements 

Fig. 32. Factors for Network Selection 

tt.01.07 4

IST Project 


Contract no.: 

026902 



Fig. 33. Network Manager Architecture 

Fig. 34. Vertical Handover Manager Architecture 

Fig. 35.Prototype application architecture 

Fig. 36. Prototype application for heterogeneous networking 

tt.01.07 5

IST Project 


Contract no.: 

026902 



Glossary 

For the purposes of the present document, the following abbreviations apply: 

ALC 

Asynchronous Layered Coding 

BAT 

Bouquet Association Table 

BTP 

Broadcast Transmission Parameter 

C/N 

Carrier to Noise Ratio 

DIT 

Diversity Information Table 

DVB-H/T 

Digital Video Broadcasting – Handheld / Terrestrial 

EIT 

Event Information Table 

EPG 

Electronic Program Guide 

ES 

Elementary Stream 

ESG 

Electronic Service Guide 

FEC 

Forward Error Correction 

FLUTE 

File delivery over Unidirectional Transport 

INT 

IP/MAC Notification Table 

IP 

Internet Protocol 

IPDC 

IP DataCast 

LCT 

Layered Coding Transport 

LOC 

Line Of Sight 

MAC 

Media Access Control 

MBMS 

Multimedia Broadcast and Multicast Service 

MPE 

Multiprotocol Encapsulation 

MPEG 

Moving Picture Experts Group 

NIT 

Network Information Table 

NLOS 

No Line Of Sight 

OFDM 

Orthogonal Frequency Division Multiplex 

PAT 

Program Association Table 

PID 

Packet Identifier 

PMT 

Program Map Table 

PSI 

Program Specific Information 

QAM 

Quadrature Amplitude Modulation 

QPSK 

Quaternary Phase Shift Keying 

RDP 

Receive Diversity Parameter 

RTP 

Real Time Protocol 

SDP 

Session Description Protocol 

SI 

Service Information 

TDP 

Transmit Diversity Parameter 

TPS 

Transmission Parameter Signalling 

TS 

Transport Stream 

XML 

eXtensible Markup Language 

tt.01.07 6

IST Project 


Contract no.: 

026902 



1 Introduction 

This document is deliverable 2.2 produced within the EU IST project PLUTO. PLUTO project is dealing with 

the optimization of physical transmission layer for DVB terrestrial systems operating with in various 

environments and circumstances. There are at present two DVB terrestrial systems, DVB-T for television 

broadcast and DVB-H for mobile television broadcast. These systems were designed not only for stationary but 

also for mobile environment. In the case of DVB-T mobility has not been primary issue but for the DVB-H it 

will play primary role. Mobile TV based on the DVB-H standard will ultimately have to operate in every 

possible place and it may with time have diverse offering of services. 

One can also speculate that in the future mobile broadcast systems will operate not only over DVB systems but 

also through other proposed mobile broadcast standards (e.g. DMB, Media Flo), and via diverse broadband 

wireless networks: 3G, WLAN and WiMax. This will make the landscape of mobile broadcast much more 

complicated than anything which exists today. 

Among the problems important for mobile broadcast are network discovery and handover. Network discovery 

means how the terminal finds a network in a specific location. Handover means how the terminal keeps delivery 

of content when changing location beyond the range of single transmitter. Handover and network discovery are 

critical for user satisfaction and service acceptance. Robust solutions to these problems are very much desired. 

In this document problems involved in network discovery and handover are investigated. Emphasis is put on 

mobility aspects and future technical environments. The problems on which this document is concentrated are 

discussed below: 

1.1 Multicast & Broadcast 

Mobile TV, if it is to become a reality and a good business model, will need to be able to target a large audience 

of users. However, the bandwidth of the network should not be dependent on the number of users but on the 

diversity of services. The traditional unicast mode is thus not appropriate for this mass content delivery, and 

multicast or broadcast mode has to be used. 

Multicast 

Internet Protocol (IP) multicast is a bandwidth-conserving technology that saves bandwidth by 

simultaneously delivering a single stream of information to a group of terminals. To receive that particular 

multicast stream, the terminal has to join the multicast group to which the stream is being sent so that the 

stream can be copied till it reaches the terminal as seen in Fig. 1. 

Broadcast 

Broadcast mode is a bandwidth-conserving technology that saves bandwidth by simultaneously delivering a 

single stream of information to a group of terminals. Terminal do not need to join the group and anybody 

can just start receiving the stream as seen in Fig. 1. 

tt.01.07 7

IST Project 


Contract no.: 

026902 



Fig. 1. Multicast vs Broadcast mode 

1.2 Review of Broadcast Networks 

Digital Video Broadcast - DVB-T/H 

DVB-T is designed for Digital TV reception and mainly targets stationary devices. DVB-H is a standard for 

mobile television based on the existing DVB-T [1] [2]. It enhances the more traditional digital television 

broadcast standard with features required to satisfy requirements specific to handheld devices; mobility, smaller 

screens and antennas, indoor coverage and reliance on battery power. 

The most essential new features of DVB-H are in the way data is organized and sent. The first of them is time 

slicing which allows data to be sent in bursts. Bursty transmission may significantly contribute to the reduction 

of battery power consumption on the terminal side, allowing the terminal receiver to be switched off after 

loading its input buffer with a burst of data. Indeed, service multiplexing in DVB-H is made in a time-division 

multiplex. Transmission of data for a particular service is not done in continuous way but is organized in 

periodical bursts with an off-time period in between. The receiver, synchronized to the burst can then power off 

during the off-time period and therefore save power. This off-time can also be used by the receiver to perform a 

seamless channel handover between two DVB-H cells. However, time slicing may also bring along increased 

channel selection delay, due to the waiting time for the next burst. DVB-H uses MPEG-4 part 10 (H.264) for the 

video and HE ACC (High-Efficiency Advanced Audio Coding) for the audio. 

Digital Media Broadcasting – DMB 

DMB is a digital radio transmission system for sending multimedia services to mobile devices [3]. T-DMB is 

the terrestrial transmission version whereas S-DMB is satellite transmission version. DMB is based on the 

Eureka 147 Digital Audio Broadcasting (DAB) standard. T-DMB can operate on radio frequency bands band III 

(VHF) and L (UHF). T-DMB uses MPEG-4 Part 10 (H.264) for the video and MPEG-4 Part 3 BSAC or HE- 

AAC for the audio. The audio and video is encapsulated in MPEG-2 TS. The stream is encoded using Reed- 

Solomon code with parity word of 16 bytes length and interleaved. In order to reduce the channel effects 

(fading and shadowing) DMB transmitters uses OFDM-4DPSK modulation. T-DMB is an ETSI standard (TS 

102 427 and TS 102 428). 

tt.01.07 8

IST Project 


Contract no.: 

026902 



MediaFlo 

MediaFlo is mobile broadcast system proposed by Qualcomm [4]. It is a proprietary technology to broadcast 

data to mobile devices which include audio and video streams, individual video and audio "clips", as well as 

information such as stock market quotes, sports scores, and weather reports. The MediaFLO system transmits 

data on a frequency separate from the frequencies used by current cellular networks. In the United States, the 

MediaFLO system will use frequency spectrum at approximately 700 MHz, which was previously allocated to 

UHF TV Channel 55. 

Multimedia Broadcast and Multicast Service – MBMS 

MBMS is a broadcasting technology that can operate via existing GSM and UMTS cellular networks [5]. The 

infrastructure offers an option to use an interaction channel between the operator and the user, which is an 

advantage, compared the other unidirectional broadcast networks. UMTS MBMS offers up to 256kbit/s per 

MBMS Bearer Service and between 800kbit/s and 1.7Mbit/s per cell/band whereas GSM MBMS offers 

between 32kbit/s and 128kbit/s. The MBMS User Service is basically the MBMS Service Layer and offers a 

Streaming- and a Download Delivery Method. The Streaming Delivery method can be used for continuous 

transmissions like Mobile TV services. The Download Method is intended for "Download and Play" services. 

To increase the transmission reliability, an application layer FEC code may be used. Further, a file-repair 

service may be offered to complement the download delivery method. MBMS has been standardized in various 

groups of 3GPP (Third Generation Partnership Project), and the first phase standards are found in UMTS 

release 6. 

Wi-Fi 

Wi-Fi is a name used to describe technology of wireless local area networks (WLAN) based on the IEEE 

802.11 standards. It was developed to be used for mobile devices, such as laptops, and to have a cordless 

environment, but is now increasingly used for more services, including Internet and VoIP mobile devices, and 

basic connectivity of consumer electronics such as televisions and radios, or digital cameras. Many standards 

were developed and are shown in Fig. 2. 

Fig. 2. Wi-Fi standards and specifications 

WiMAX 

WiMAX stands for Worldwide Interoperability for Microwave Access and was defined by the WiMAX Forum, 

formed in June 2001 to promote conformance and interoperability of the IEEE 802.16 standard, officially 

known as WirelessMAN. The Forum describes WiMAX as "a standards-based technology enabling the delivery 

of last mile wireless broadband access as an alternative to cable and DSL". The original WiMAX standard 

(IEEE 802.16) specified WiMAX for the 10 to 66 GHz bands range. 802.16a, updated in 2004 to 802.16-2004 

(also known as 802.16d), added specification for the 2 to 11 GHz range. 802.16d (also known as "fixed 

WiMAX") was updated to 802.16e in 2005 (known as "mobile WiMAX") and uses scalable orthogonal 

frequency-division multiplexing (OFDM) as opposed to the OFDM version with 256 sub-carriers used in 

802.16d. This brings potential benefits in terms of coverage, self installation, power consumption, frequency re- 

tt.01.07 9

IST Project 


Contract no.: 

026902 



use and bandwidth efficiency. 802.16e also adds a capability for full mobility support. 

All the broadcast technologies listed above are summarized in Fig. 3. 

Fig. 3. Comparison of the main broadcast technologies 

1.3 Review of network and service discovery technologies 

By the network discovery a process is understood by which device finds available networks and services. This 

process has specific aspects for broadcast type networks since they may use broad radio spectrum and large 

selection of contents. In consequence for particular types of broadcast networks specific systems for network 

and service discovery were developed. Such systems are available and used at present for DVB-T, DVB-H and 

DAB/DMB broadcast systems. They are summarized below. 

1.3.1 DVB-T/H networks 

1.3.1.1 Network discovery 

The current system for network discovery in DVB-T/H networks is based on scanning within the frequency 

range of region/country searching for the signals. The process is time-consuming when scanning through vast 

range (e.g. 474-858 MHz) and storing information regarding each network found to the memory of the receiver. 

During the scanning the receiver goes through frequencies by taking 8 MHz steps. These selected frequencies 

are also called channels (e.g. channel 24 is centred on 498 MHz). The receiver attempts to synchronize to the 

tt.01.07 10

IST Project 


Contract no.: 

026902 



signal on every channel within the frequency range. When the signal is found the received stream is parsed and 

DVB Service Information (PSI/SI) tables are parsed. These tables contain information about the networks and 

contents. The process starts with the Network Information Table (NIT). If NIT is found, the PSI/SI information 

related to each transport stream is collected. In the case of DVB-H network, the support of the IP Datacast 

(IPDC) services is checked. This means that there exists a linkage to IP/MAC Notification Table in the NIT. 

Then all the essential parameters are collected and stored. The network discovery process is illustrated step by 

step in Fig. 4. 

Fig. 4. Network Discovery for DVB-H 

1.3.1.2 Service discovery in DVB-T and DVB-H 

Service discovery in DVB-T networks is based purely on the PSI/SI information [6] carried in the transport 

stream. Available channels and services are found by using the Program Map Table (PMT) and the Program 

Association Table (PAT), where the services are mapped. DVB-H networks also rely on the PSI/SI information 

with IP specific extensions, but in addition, the Electronic Service Guide (ESG) is introduced for service and 

content discovery. The information provided by ESG is categorized in two types, user attraction information 

and content acquisition information. Available services are displayed to the user with short descriptions. The 

user can also acquire more detailed information about the services of interest. The terminal device also needs 

information for launching the service. Hence, the necessary details for service acquisition, and the technical 

description of the service content for displaying it properly are provided in the ESG. For broadcasting on-line 

services in DVB networks, there exists also the TV-Anytime concept, which introduced an XML-based data 

model for describing the content of services and other useful metadata. The ESG data model is partly based on 

tt.01.07 11

IST Project 


Contract no.: 

026902 



the TV-Anytime model. 

1.3.1.2.1 PSI/SI service information 

The Program Specific Information (PSI) and Service Information (SI) are carried in tables within the transport 

stream to map the programs and services, which it contains. These tables are the Network Information Table 

(NIT), Program Association Table (PAT), Program Map Table (PMT) and IP/MAC Notification Table (INT). 

The NIT announces available transport streams with their IDs and linkage descriptors to other tables. In the 

traditional DVB-T network services are mapped by using PATs and PMTs. The PAT contains information 

about every DVB service in the transport stream and associates them to the corresponding PMTs. The PMT 

provides the mapping of a specific program with its elements (video, audio, subtitles). In the DVB-H network 

data are delivered as IP streams. Therefore, the INT is used to announce the addresses of the IP streams and 

map them with the services. 

1.3.1.2.2 TV-Anytime information 

TV-Anytime standard [85] presents a metadata model for managing the variety of the content of broadcast and 

on-line services. The TV-Anytime Forum has adopted XML as the common representation format for 

documentation of metadata and introduces the TV-Anytime Schema for describing the metadata. However, the 

use of XML format is not obligatory when representing TV-Anytime metadata. Optimized binary format may 

be used to conserve bandwidth or to aid rapid processing and mapping to a database. When using XML as 

metadata exchange format, it is strongly recommended that the structure conforms to the TV-Anytime Schema. 

In the Schema, metadata is divided in six groups depending on its nature: 

- Content description metadata 

- Instance description metadata 

- Consumer metadata 

- Segmentation metadata 

- Meta origination information metadata 

- Interstitial and targeting metadata 

All TV-Anytime metadata is grouped under a root element called “TVAMain”. The diagram in Figure 5 

illustrates this relationship and what type of metadata every group contain. 

tt.01.07 12

IST Project 


Contract no.: 

026902 



Fig. 5. The grouping of TV-Anytime metadata 

1.3.1.2.3 ESG information 

In the DVB-H system the Electronic Service Guide (ESG) plays major role in service discovery, in addition to 

PSI/SI. The ESG provides information on many levels. It contains the data displayed by the ESG application on 

the terminal device. These service descriptions are meant for the user to make selections. The details of the 

service acquisition for the device are provided as well as the content description of the service for the 

application running it. To provide all this information in well-formed, consistent and interoperable manner, the 

ESG specification [7] presents the data model, which describes the structure of the ESG. The model is defined 

based on XML Schema and the contents are divided in seven fragments in order to manage and deliver them 

independently. The ServiceBundle, Purchase and PurchaseChannel fragments provide information about service 

groups and how to purchase them. The Service fragment describes the basic features of the service and the 

Content fragment specifies more detailed information about the contents of the service. The Acquisition 

fragment provides information needed for the service acquisition and launching it, like SDP data for video 

streams etc. The ScheduleEvent fragment specifies time-dependant contents in the service and acquisition 

reference when these particular contents are available. The ESG fragments and their relations are illustrated in 

Fig. 6. 

tt.01.07 13

IST Project 


Contract no.: 

026902 



Fig. 6. ESG structure 

1.3.2 DMB/DAB 


Digital Media Broadcasting (DMB) is a digital radio transmission system based on Digital Audio Broadcasting 

(DAB) system [8]. DAB has four transmission modes, which are dependent on the system operating conditions. 

Transmission mode I is intended to be used for terrestrial Single Frequency Networks (SFN) and local-area 

broadcasting in Bands I, II and III. Modes II and IV are intended to be used for terrestrial local broadcasting in 

Bands I, II, III, IV, V and in the 1452 MHz to 1492 MHz frequency band (L-Band). It can also be used for 

satellite-only and hybrid satellite-terrestrial broadcasting in L-Band. Transmission mode III is intended to be 

used for terrestrial, satellite and hybrid satellite-terrestrial broadcasting below 3000 MHz. For cable distribution, 

transmission mode III is the preferred mode because it can be used at any frequency available on cable. 

However, transmission modes I, II and IV may also be used, depending on the chosen frequency band. For the 

receiver to perform network discovery it is supposed to tune in the preferred radio frequency band. If DAB 

signal exists, Service Information (DAB-SI) is provided. 

1.3.2.2 Service discovery 

Service Information (SI) provides supplementary information about services, both audio programme and data. 

These features are provided in the Fast Information Channel (FIC) and they are: 

- Service component language 

- Time and country identifier 

- Programme Number 

- Programme Type 

- Announcements 

- DRM (Digital Rights Management) services 

- Frequency Information 

tt.01.07 14

IST Project 


Contract no.: 

026902 



- Transmitter identification 

- Other ensembles 

- FM services 

- FIC re-direction 

- Ensemble label 

- Service label 

- Service linking information 

- Regional identification 

- AMSS services 

- AM services 

- User application information 

Also, the Electronic Program Guide (EPG) is provided for service listings and as a mechanism for the user to 

select services, programmes and related content. EPG data is described by using XML model to achieve a 

flexible structure to make EPG functional on a range of receivers with differing display capabilities, resources 

and return channel capabilities. The XML model for DAB/DMB is specified in [9]. It is divided into service 

information (ensembles and services) and programme information (schedules, programmes, groups and events). 

Additionally programmes and events can be linked together into groups. 

1.3.3 MBMS 


Multimedia Broadcast Multicast Service (MBMS) [5] can operate via existing GSM and UMTS cellular 

networks. In GSM systems, MBMS uses GPRS and EDGE modulation and coding schemes. MBMS also uses 

the GPRS and EDGE packet data channel (PDCH) for point-to-multipoint transmissions, and the radio link 

control/medium access control (RLC/MAC) protocols on layer 2. MBMS also supports multi-slot operation for 

point-to-point transmissions, where the radio network may use up to four timeslots per MBMS session. In 

WCDMA UTRAN systems, MBMS reuses existing logical and physical channels to the greatest possible 

extent. The implementation in WCDMA requires only three new logical channels and one new physical 

channel. The new logical channels are MBMS point-to-multipoint control channel (MCCH), which contains 

details concerning ongoing and upcoming MBMS sessions; MBMS point-to-multipoint traffic channel 

(MTCH), which carries the actual MBMS application data; and MBMS point-to-multipoint scheduling channel 

(MSCH), which provides information on data scheduled on MTCH. The new physical channel is the MBMS 

notification indicator channel (MICH) by which the network informs terminals of available MBMS information 

on MCCH. 

1.3.3.2 Service discovery 

MBMS user service announcement/discovery mechanisms allow users to request or be informed about the range 

of services available, both operator specific MBMS user services and services from content providers outside of 

the PLMN (Public Land Mobile Network) are included. Service announcement is used to distribute to users 

tt.01.07 15

IST Project 


Contract no.: 

026902 



information about the service, parameters required for service activation (e.g. IP address) and possibly other 

service related parameters (e.g. service start time). Several service discovery mechanisms are considered 

depending on the capability of the user terminal. These are SMS Cell Broadcast, MBMS Broadcast mode, 

MBMS Multicast mode, PUSH mechanism (WAP, SMS-PP, MMS) and URL (HTTP, FTP). For the user 

terminal to perform service discovery and the service provider to make service announcement, certain agreed 

metadata information is needed. These MBMS user service description metadata fragments are described in [5]. 

The metadata consists of fragments describing a single or a bundle MBMS user services, MBMS user service 

sessions, associated delivery methods, service protection and the FEC repair data stream. The relations between 

metadata fragments are illustrated in Fig. 7 in the case of a single user service bundle description. 

User 

Service 

Bundle 

Description 

1 

includes 

1..N 

User 

Service 

Descript. 

1 

FEC 

Repair 

Stream 

Descript. 

reference 

0..1 

Associated 

Delivery 

Procedure 

Description 

references 

0..1 

1..N 

1..N 

1..N 

references 

Delivery 

Method 

1..N 

Session 

Description 

1..N 

references 

0..1 1 

0..1 

1..N 

includes 

1..N 

0..1 

Security 

Description 

Fig. 7. MBMS service metadata fragments 

1.3.4 MediaFlo 


The MediaFlo media distribution system (MDS) [4] is a product of Qualcomm and it is designed for 3G 

(UTMS) networks, primarily CDMA2000-based as it is the technology used in the U.S. The MDS focuses on 

providing the experience of real-time media while minimizing the cost of content delivery. Hence, the system is 

designed to deliver a significant volume of multimedia content to a large number of subscribers by using offpeak 

capacity whenever possible. In other words, the content is delivered to the subscribers when they are in the 

range of the 3G network and the hours when network load is low are preferred for delivery. By storing the 

delivered content on the device the system is not always actual real-time, but it gives to the user the possibility 

tt.01.07 16

IST Project 


Contract no.: 

026902 



to access content also when being out of the reach of the network. 

1.3.4.2 Service discovery 

For the service discovery, the MediaFlo system presents the Media Program Guide (MPG). It is the user 

interface for the MDS system offering information in two dimensions: which programs/services are available 

overall, and when individual programs/services are available for viewing. The appearance of the MPG reminds 

more electronic program guides from cable, satellite or digital television than web-based interface for media 

viewing. The intention of this approach is to offer information about the time when the ordered content is 

available and hide the details referring to the delivery of the content, like progress bars familiar from webinterfaces. 

The smallest unit to receive in the MDS is called Service. The Service is actually a collection of 

individual contents, it may be compared to the traditional channel in television. For the subscription, groups of 

services are collected as packages, which the users can purchase. 

1.4 Network and Service Discovery problems 

Broadcast systems in which content is delivered to consumers require knowledge of how the content can be 

accessed. This becomes more and more complicated as the content delivery offering is increased. Digital 

broadcast systems provide certain mechanisms for dealing with network discovery. The first, and very old 

mechanism, is just scanning all the broadcast channels in order to discover which of them are used for 

broadcast. The second mechanism is using standardized system information (SI) in the broadcast stream in 

which the broadcast information is described for particular network and channels. 

The SI mechanism used in DVB-T is sufficient for standard TV broadcast in a stationary environment where the 

system information is rarely changing. The situation is very different in a mobile environment where users are 

roaming. Network discovery is then a critical aspect of user satisfaction with the technology and the service. In 

an environment where users are on the move network discovery should ideally be as fast as possible and as 

comprehensive as possible. These requirements are not satisfied best with the present approach via SI since it is 

limited to a single network and would require scanning all available channels to find all available networks. The 

problems will be even bigger in future heterogeneous networking environments in which broadcast content may 

be delivered by several types of broadcast systems (DVB, DMB, MediaFlo), over 3G network broadcast and 

using multicast in WLAN and Wimax systems. That can result in such a large number of possibilities that new 

mechanisms for network and service discovery will be definitely required. In this document the problems 

related to network and service discovery in mobile systems are considered and solutions for them are proposed. 

Emphasis is put on future systems where new effective solutions will be very much needed, as illustrated in Fig. 

8. 

tt.01.07 17

IST Project 


Contract no.: 

026902 



1.5 Handover problems 

Fig. 8. Service Discovery Problems 

Handover is a basic operation which makes cellular communication possible. In the past broadcast systems 

handover has not been necessary due to the stationary location of receivers. This has changed with the 

introduction of mobile broadcast systems where handover for broadcast is an important aspect of the 

technology. Users expect seamless handover which means unnoticeable change of reception between different 

transmitters. In contrast to cellular systems handover for broadcast is essentially made exclusively by the 

terminal without assistance from the network. This requires a sufficient level of intelligence in the terminal. 

One can talk about horizontal handover which is the term used for describing handover executed within a single 

broadcast system. Vertical handover is in turn executed between different broadcast systems providing the same 

content. In this document both horizontal and vertical handover cases for broadcast are considered. There is an 

existing body of research concerning horizontal handover for DVB systems while vertical handover issues for 

broadcast are only now becoming a topic of research. Solutions facilitating handover in both cases including 

algorithms for handover are considered in this document. In the case of vertical handover a general model is 

built and taxonomy of different cases is provided. 

tt.01.07 18

IST Project 


Contract no.: 

026902 



2 Network and service discovery in mobile broadcast 

systems 

As we stated previously, traditional network and service discovery process in heterogeneous environment would 

be very slow: scanning through the whole frequency range and different networks would take time and consume 

battery power. There is a possibility for considerably improving the process by unifying the discovery process 

across different broadcast networks or if the receiver is equipped with a positioning system. The networking 

environment could then be described in an Universal directory or in position database maps and used for 

network and service discovery. We will discuss those improvements in the following chapter. 

2.1 Improving Network & Service Discovery for Broadcast Network 

2.1.1 Position Assisted Discovery System 

Position-assisted service discovery concepts were first introduced in [10], [11], [12] and [13]. The most relevant 

for us, [13] defines a Hybrid Information System (HIS) and aimed at making measurements of each network 

system available to the heterogeneous systems as well, thus allowing mobiles to benefit from other mobiles 

measurements via a HIS. The HIS saves lots of effort as the continuous scanning mode is dropped. We support 

this idea and we want to extend the HIS concept to overlay those coverage information on Satellite maps used 

by Galileo or GPS systems. Indeed, in the near future, every mobile terminal will be equipped with a satellite 

positioning system. The maps used in those systems can be associated with a Localisation and Coverage 

Estimation of the transmitting systems in which transmitter characteristics and coverage are represented as in 

Fig. 9. This overlay information will provide a mobile device equipped with positioning system with 

information about network availability and coverage at a specific location, saving time and battery of scanning 

the whole environment. The reports done by mobile devices or other field measurements could form a so called 

RegionMapUpdate element to update mobiles´ system. 

Fig. 9. Localisation and Coverage Estimation TUT (Finland) DVB-H Transmitter 

tt.01.07 19

IST Project 


Contract no.: 

026902 



2.1.2 Universal Network and Service Discovery 

The way in which networks and services discovery is actually done depends primarily on their existing 

infrastructure and protocols for supporting discovery (MPEG2-TS, XML, SDP, etc.). Moreover, their actual 

implementation lacks unification, making inter-system discovery across heterogeneous networks virtually 

impossible. For efficient network and service discovery in various mobile broadcast networks, we introduce the 

concept of Universal Network and Service Discovery. 

Fig.10. Universal Network & Service Directory 

The basic idea behind the Universal Network and Service Discovery (UNSD) is described in Fig. 10. Instead of 

getting information about one particular network at a time, using a specific discovery system, we use a directory 

which has information about all the networks and the services they provided at certain location, making intersystem 

discovery and handover between them easier and faster. Indeed, the discovery information is retrieved 

once for the network region, saving tuning and searching time. In order to do that, each Content and Service 

Provider must report what content is provided and to which system this content is forwarded as shown in Fig. 

11. 

Fig. 11. Discovery Agent for Universal Network & Service Directory 

tt.01.07 20

IST Project 


Contract no.: 

026902 



The UNSD proposed is an extension of the DVB Standard - Electronic Service Guide (ESG) [7] - which is 

based on the widely used XML standard. However the original ESG standard model can not associate a 

specific service to different networks, this is what we address in the following, as shown in Fig. 12. 

Fig. 12. New UNSD model based on ESG 

In the PLUTO project Deliverable 2.1 – Service Scenario Specification, a NetworkAreaTable was added to the 

ESG Standard. It includes a NetworkType element to describe if the network is DVB, DAB, Flow, WiMAX etc. 

and a NetworkCell element which contains the necessary diversity information. 

We propose to further extend this proposal and enable the ESG to become full UNSD to be used in a 

heterogeneous environment and across different network technologies. The necessary information to enable 

inter-system discovery is included in the newly defined NetworkAreaTable, NetworkSubscriptionTable and 

NetworkSubscriptionChannelTable as shown Fig. 13. 

Fig. 13. UNSD: ESG with extended NetworkAreaTable and new NetworkSubscriptionTable 

tt.01.07 21

IST Project 


Contract no.: 

026902 



The modification of the NetworkAreaTable concerns the NetworkCell element which is extended with a 

CellFrequency element and a TuningInfo element so that the NetworkCell element can provide all the necessary 

information for a receiver to tune to the described network as show in Figs 14 and 15. Moreover, an 

AcquisitionRef element is added to specify the generic information for the acquisition of this network. 

Fig. 14. Proposed Extension to Network Area Information Fragment 

Fig. 15. Extension to NetworkCell element 

Moreover, the new NetworkSubscription fragment added to the ESG standard enables a user to subscribe to a 

particular network. This fragment specifies the subscription information of a network which can be displayed 

to the end user for information purposes. The Network Subscription fragment is described by its name, 

provider, reference, description, price and usage constraints as shown in Fig. 16. 

tt.01.07 22

IST Project 


Contract no.: 

026902 



Fig. 16. Proposed Network Subscription Fragment 

In addition to the NetworkSubscription fragment, a NetworkSubscriptionChannel is added to the ESG. The 

network subscription channel is a structure through which a user or a terminal interacts with the network 

subscription system. It is described in Fig. 17. 

Fig. 17. Proposed Network Subscription Channel Fragment 

To complete the proposed ESG and make services dependent to networks, the Services need a reference to the 

network where it can be found. In a heterogeneous environment, services can be broadcasted over several 

different networks (DVB, Wi-Fi, WiMax, MBMS, etc.). This addition is shown in Fig. 18. 

tt.01.07 23

IST Project 


Contract no.: 

026902 



Fig. 18. New NetworkRef element in the Service fragment 

The overall structure of the new UNSD is shown in Fig. 19. The advantage of this new UNSD is that it can also 

be used as such in actual DVB-H networks but it can also be used in any other networks, making a unified 

Network Discovery System. 

tt.01.07 24

IST Project 


Contract no.: 

026902 



Fig. 19. New structure of the proposed UNSD 

3 Horizontal handover in broadcast networks 

3.1 Scenario for horizontal handover in DVB-H network 

Multi-Frequency DVB-H networks can be made of low power transmitters with a relatively small cell size. As 

cell size decreases handover becomes an increasingly important issue. Handover in DVB-H consists of the 

switching of the reception of IP based services from one transport stream to another as the terminal moves from 

one cell to another [1]. DVB-H handover can occur only within MFN networks, between two different SFNs 

that are part of the same network, and between two different DVB-H networks. If localized services are not 

supported within a network, the network can consist of a single SFN area where handover is not needed. Soft 

handover usually means that additional transport streams are received and existing transport streams are 

disconnected in such a way that the DVB-H terminal is always receiving at least one transport stream [25] so 

that the transport stream is changed without interruption to the received service. 

Time slicing (in the data link layer) and DVB-H signalling (in the data link layer and the physical layer) are the 

features of DVB-H that are directly used in the DVB-H handover process. Time slicing is used to transmit data 

in periodic bursts reducing the power consumption of the receiver. It also enables the receiver to be used to 

monitor neighbouring cells between the bursts making soft handover possible. 

Two types of signalling information are used by the receiver for handover, Transmission Parameter Signalling 

(TPS) signalling bits in the physical layer, and DVB-H specific signalling within the Program Specific 

Information (PSI)/Service Information (SI) [6] [26] [27]. The signal for synchronization in the handover process 

is obtained using information contained in the TPS bits [28]. The receiver finds a specific IP based service in a 

specific transport stream using information contained in a subset of PSI/SI for IP based services over DVB-H 

defined in [29]. Handover related information in the PSI/SI is mainly contained in the NIT (Network 

Information Table), the PAT (Program Association Table), PMT (Program Map Table) [6] and INT (IP/MAC 

Notification Table) [26]. The Synchronization Word bits aid the receiver in synchronizing with the target 

frequency. The Cell Identifier conveys unique cell identification information to the receiver. 

An INT may announce the association of IP streams within all the transport streams of the network or just 

within the transport streams available in neighbouring cells. In a MFN network capacity is saved if each INT 

announces only the association of the IP streams available in neighbouring cells. This requires the receiver to 

update the INT after each handover. For handover between two different DVB-H networks the relevant NIT is 

needed for each network supported in addition to the current network. 

tt.01.07 25

IST Project 


Contract no.: 

026902 



Although some DVB-H terminals have telecommunication capabilities, it is not always possible for the terminal 

to contact the telecommunication network to perform handover. Handover in DVB-H without an interaction 

channel is called passive handover while handover that utilises an interaction channel is called active handover 

[30]. As the DVB-H standard does not require a DVB-H terminal to have an interaction channel most research 

on handover in DVB-H has focussed on passive handover. 

3.1.1 Review of the state of the art 

Handover in DVB-H consists of three stages: handover measurement, handover decision-making based on the 

handover criteria, and handover execution [31]. 

The first handover scheme for DVB-H to appear in the literature is in Väre and Puputti [32]. The RSSI 

(Received Signal Strength Indication) value of the current cell and the RSSI values of its adjacent cells are 

measured during the off burst time. These values are compared and the receiver hands over to the cell with the 

strongest RSSI value if it is not that of the current cell. An RSSI value can vary due to multipath, interference or 

other environmental effects so may not give a true indication of the communication performance or the range. 

Repeatedly measuring a varying RSSI value will result in the Ping Pong effect in handover measurement which 

will consume battery power unnecessarily. To overcome this problem a better handover algorithm had to be 

developed. 

Yang et al [25] proposed a SNR based handover scheme based on post-processing of the measured SNR value 

to avoid the Ping Pong effect and to get rid of the received “fake signals”. The SNR is calculated from the RSSI 

and the noise characteristics and provides a more accurate estimate of the received effective signal than the 

RSSI. The main idea of post-processing the SNR values is to calculate the CDFs (Cumulative Distribution 

Functions) of all the SNR values. A Cumulative Distribution Function describes a statistical distribution. It 

gives at each possible outcome of the received signal SNR the probability of receiving that outcome or a lower 

one. Because the CDF gives a probability value, its value depends not only on the current SNR value but also 

on the SNR history of the signal. This eliminates the frequent handover phenomenon and avoids the “fake 

signals” caused by frequency confusion. Simulation has shown the feasibility of the SNR based handover 

scheme. 

Hamara presented an enhanced version of the algorithm of [32] in his Masters thesis [33] which is the first 

devoted to DVB-H handover in the literature. In addition to using the RSSI value, currently consumed services 

and bit error rate are taken into account in making the handover decision. Hamara [33] gives an extensive 

analysis of handover aspects of DVB-H. 

May [34] has shown how the off times between the transmissions bursts can be used to perform handover, how 

they have to be synchronized and what boundary conditions exist. A technology called “phase shifting” is 

proposed as a solution. 

Vare, Hamara and Kallio [35] proposed a method for signalling cell coverage areas by means of bitmap data to 

improve handover performance in DVB-H. A new table called the Cell Description Table (CDT) was proposed 

for the PSI/SI. By using a CDT up to 256 different signal levels within the cell coverage area can be signalled to 

the receiver to inform it of the cell coverage. The terminal can make better handover decisions using this 

information reducing the Ping Pong effect and “fake signals”. However, to support the CDT information 

process this proposed handover scheme requires more bandwidth and receiver memory. In addition the DVB-H 

receiver must have GPS support. The cost of identifying the location of the user can be transferred from the 

terminal side to the network side if the network can provide location information. 

Yang et al. [31] proposed a hybrid handover decision-making algorithm based on a number of handover 

decision-making algorithms which could include Context Aware Handover Decision-making, Location Aided 

Handover Decision-making, UMTS Aided Handover Decision-making, Repeater Aided Handover Decision- 

tt.01.07 26

IST Project 


Contract no.: 

026902 



making, and Hidden Markov Model Based Decision-making. The idea is to reduce the frequency of handover 

measurement in the handover decision-making stage by designing a soft handover algorithm that predicts the 

moment of handover. The different handover decision-making algorithms have different advantages and 

disadvantages depending on the scenario in which they are used. By using a central management module to 

choose the handover algorithm to be used in a particular scenario the advantages of the different algorithms can 

be exploited while their disadvantages can be minimised. 

Schwoerer [28] [36] and Vesma [28] target power consumption reduction by utilising novel synchronization 

techniques in the handover execution stage of the handover process. The handover execution stage is equal to 

the signal synchronization and the on-time in the time slicing mode consists of both the synchronization time 

and the burst data duration time. The main idea of [28] and [36] is to minimize the synchronization time to 

further reduce the power consumption. The main exploitable synchronization time in the synchronization stage 

is the TPS synchronization [28]. 

Schwoerer and Vesma [28] proposed a new synchronization technique called correlation-based “Fast Scattered 

Pilot Synchronization” for DVB-H receivers to substitute the conventional TPS based OFDM frame 

synchronization for finding the position of Scattered Pilots within an OFDM symbol in the handover execution 

stage. It exploits the temporally repetitive structure of the scattered pilots and Schwoerer and Vesma [28] 

showed using mathematical analysis that the synchronization time (until channel estimation) could be cut by 

84% by using the new technique. Reducing the synchronization time means reducing the power consumption. 

Therefore, “Fast Scattered Pilot Synchronization” can reduce the power consumption in the DVB-H handover 

execution stage. Schwoerer [36] proposed another purely power-based “Fast Scattered Pilot Synchronization” 

method. It uses the fact that scattered pilots are amplitude-boosted by 4/3 to find the current Scattered Pilot 

Raster Position (SRPR) [2]. It is shown in [36] that 89% of the synchronization time can be saved using powerbased 

“Fast Scattered Pilot Synchronization”. 

In [34] May focussed on the handover execution stage of the handover process in DVB-H. Because the IP 

network delay and jitter may be different for different cells May proposed a technology called “phase shifting” 

to synchronize the signals of adjacent cells in IP Datacast over DVB-H networks in order to ensure loss-free 

handovers. When the terminal moves from one cell to another, synchronization techniques must be used to 

ensure that there is no packet loss caused by a time sliced burst overlap when the next time sliced burst arrives. 

There are three different possibilities for the types of synchronization. The first is no synchronization that of 

course will cause considerable packet loss. The second is in-phase synchronization where all the transport 

streams in different cells must be transmitted in perfect synchronization, that is, at the same universal time. This 

cannot be ensured without a buffer system in the network side. The third one is “phase shifting” synchronization 

where there is a time shift between adjacent cells to ensure that there is enough time between the neighbouring 

time slices to avoid the possible packet loss caused by time slice overlap. Analysis and simulation showed that 

the phase shifting synchronization techniques can achieve much better performance with respect to the packet 

loss probability compared with the no synchronization and “in phase” synchronization techniques. 

The DVB Project technical reports [27] and [2] propose a simple handover algorithm for handover in DVB-H 

based on the handover algorithm in DVB-T. The basic idea is for the DVB-H terminal to use the 

terrestrial_delivery_system_descriptor, the frequency_list descriptor, the original_network_id and the 

transport_stream_id together as a pair along with the service_list_descriptor to decide which frequency and 

transport stream the receiver should switch to in the handover process. Several methods to reduce the risk of 

tuning failures or “fake signals” are also presented. The first one proposed in [27] is called “local SI insertion” 

which makes each cell a separate network by individual Service Information (SI) insertion. In this case, there 

will be only one frequency per network. The second method utilises the cell identifier so the terminal can know 

which cell it has entered. In this case, the terminal can determine and check the cell id of a signal from its TPS 

bits to see if it is in its cell id list of interest after checking the frequency thus reducing the tuning failure. The 

third method uses location data from GPS receivers to aid the handover so the terminal can determine the 

destination cell reducing tuning failure. The last method in [27] uses two front-ends including a second 

demultiplexer. In this case, the tuning of different frequencies can be done in parallel and the target cell 

frequency can be validated in advance so that the risk of tuning failure can be completely eliminated. 

tt.01.07 27

IST Project 


Contract no.: 

026902 



A more detailed description of different handover algorithms especially of the different handover decisionmaking 

algorithms in dedicated DVB-H networks and in converged DVB-H/UMTS networks is presented in 

[37]. The investigation and research of the handover in converged DVB-H and UMTS networks is thought to be 

one of the first in the literature. 

Research on passive handover in DVB-H appears to have slowed since March 2006 because the next important 

step for handover in DVB-H is field testing so that the limitations of the algorithms proposed can be 

investigated and worked on. As the DVB-H service was commercially deployed for the first time in Italy mid 

2006 using large cells, there is probably still a long way to go before handover in DVB-H is really taken 

seriously by the operators, etc. At the moment, it seems that research into handover in DVB-H is moving on to 

looking at vertical handover. The move in this direction is exemplified by May, Buburuzan and Unger [38] in 

which different terminal-initiated handover mechanisms together with roaming possibilities for converged 

DVB-H and cellular telecommunication networks are presented. The advantages and disadvantages of these 

mechanisms are described. From these, the requirements for a terminal mobility support implementation are 

extracted. Mobility architecture for a terminal with DVB-H and telecommunications capabilities operating in a 

converged DVB-H and telecommunications network is presented that is based on the identified requirements. 

The paper describes the functionalities, components, and interfaces that are needed to support the different 

handover options in an efficient way. The trade-off between complexity and handover performance is discussed, 

leading to different profiles. A mapping to the IEEE 802.21 (Media Independent Handover) framework is 

presented in order to provide a standardized interface to the higher protocol layers. This interface opens the 

possibility for seamless integration of other additional wireless technologies, both unidirectional and 

bidirectional in a single terminal. 

3.1.2 Optimization for horizontal handover algorithms 

Designing efficient handover algorithms for DVB-H involves exploiting the opportunities to reduce battery 

power consumption. This is most critical in the handover decision-making stage where the main objective is to 

predict when handover should take place so that the number of power consuming measurements that need to be 

made to decide when handover will take place is minimised. However, the complexity of the handover 

algorithm should not be so great as to cause problems in implementing the receiver design. 

In dedicated DVB-H networks handover is passive because there is no return channel that can be used to assist 

the handover process. In a converged DVB-H and GPRS/UMTS network where a return channel is available it 

should be used to assist the handover process. Where the transmitting devices transmit network parameters 

which identify them, these parameters should be used by the receiver to assist the handover process. 

An attachment to a DVB-H terminal such as a GPS receiver can improve handover efficiency but will increase 

the price of the terminal. Ideally, additional network equipment should not be introduced just to assist the 

handover process. 

The obstacles to efficient handover, such as the Ping Pong effect, “fake signals” and power consumption, need 

to be considered collectively when designing a handover algorithm as they are interrelated. 

It is difficult to design a single algorithm for handover that works well in all usage scenarios and context 

sensitive algorithms may need to be considered. 

tt.01.07 28

IST Project 


Contract no.: 

026902 



4 Vertical handover in broadcast networks 

Vertical handover refers to a future mobile environment where it will be possible to provide broadcast services 

on a variety of networks. Research in networking strongly points towards the proliferation of multiple 

broadband wireless networks. Mobile 3G networks are enhanced by high-speed access technologies expanding 

connectivity speeds into the range of megabits per second. Wireless LAN networks are being expanded into the 

hundred megabits per second range. In the 3G network area, the MBMS (Multimedia Broadcast and Multicast 

System) standard will be used to provide broadcast and multicast services while in the WLAN area multicast 

can be utilized for broadcast services like in any other IP network. The landscape of future mobile broadcast 

opportunities may thus look as follows (Fig. 20): 

- dedicated broadcast networks (DVB-H, DMB, Media Flo, satellite) 

- broadcast in 3G mobile networks via MBMS 

- broadcast in WLAN/WiMAX networks via multicast 

Fig. 20. Future Mobile Broadcast Network 

Provision for all these networks in mobile terminals is relatively easy and there are already devices having 

connectivity to all of them. This means that the future mobile broadcast landscape might be quite complex and 

brings questions about its use. From the services point of view, the creation of a unified broadcast environment 

should be the goal. This view is enhanced by the fact that different networks may play complementary roles and 

broadcasters may want to use a combination of them for the delivery of their content. For example, one can 

imagine a broadcasting system composed of DVB-H and WLAN networks in which WLAN access points are 

used as repeaters and gap fillers integrated with the DVB-H system. Similar cooperation can be imagined with 

3G networks. A fully integrated broadcast environment can be envisioned in which network resources can be 

aggregated for the use of broadcasters. Practically this will mean a common network and service discovery 

system, like the UNSD described before, and provision for vertical handover with mobility support between 

these networks. 

tt.01.07 29

IST Project 


Contract no.: 

026902 



4.1 Scenario and taxonomy for vertical handover 

Vertical handover means changing the network type while receiving the same content. This should be done in 

an automatic and seamless way, i.e. without impact on the consumption of content. The need for vertical 

handover may be happening between any of the networks listed previously: DVB-H, 3G MBMS, WLAN and 

WiMAX. The consumer of content would be roaming freely between the networks without noticing it as shown 

in Fig. 21. 

Fig. 21. The prefect vertical handover scenario 

This however is in the case for ‘pure’ broadcast which relies on sending content on one heterogeneous network 

only. One can imagine advanced broadcast cases in which content is delivered over several networks, for 

example broadcast over DVB-H and download from WLAN multicast. Also, in the case of availability of 

multiple networks, mobile broadcast can be naturally extended with interactivity, while receiving the content, 

users would be able to send interactive responses by other networks (cellular, WLAN). 

Thus, in the most general case, vertical handover means automatic and seamless changing between several 

networks, operating both in broadcast and interactive modes. How such handover can be realized will depend 

on the overall system architecture and properties. One can see two opposite cases: 

1. The overall networking system is tightly managed to support handover 

In this case the system is implemented and controlled to avoid differences between various delivery networks. 

For example the content delivery will be synchronized to eliminate delays between the different networks. This 

will minimize the terminal’s operation for executing handover. The architecture of such system is shown in Fig. 

19. The networks are fully controlled by single operator that can optimize location, coverage and synchronize 

the content delivery to make handover simple. In the most tightly-controlled system, it is the operator that will 

be managing and controlling handover execution. This case of managed handover is shown in Fig. 22. 

tt.01.07 30

IST Project 


Contract no.: 

026902 



Fig. 22. Fully managed broadcast network 

2. The overall networking system is not managed and thus does not have facilities supporting handover 

In case of unmanaged networks, content delivery is not synchronized and may even be organized using different 

transport protocol stacks. In case of an unmanaged network the mobile device has to decide about handover and 

execute it in fully autonomous way. This will commonly happen if e.g. one of the networks is mobile TV DVB- 

H and the other one is a standard WLAN based on IP network. Terminal has to make decision about handover 

between these networks based on external and internal information about network availability and condition. 

For example, in the IP network there can be packet jitter and delays in the delivery of content because of lack of 

synchronization between the networks. This has to be taken care of in the terminal if handover is to be seamless. 

The case of unmanaged networks is illustrated in Fig. 23. 

tt.01.07 31

IST Project 


Contract no.: 

026902 



Fig. 23. Unmanaged broadcast networks system 

Between the two extremes shown in Figs. 20 and 21 there are many possible intermediate cases in which there 

will be some but not full management of the networks. It should be evident that on the terminal side there has to 

be enough support to facilitate vertical handover not only for the best case of a fully managed system but also 

for the unmanaged systems. 

From the terminal point of view, vertical handover can be operating in two modes: 

- passive mode in which all the information about conditions for handover has to be acquired by the 

terminal 

- active mode in which the networking system provides handover-specific information to the terminal 

In the active mode case, the terminal can obtain handover information from several sources: service information 

systems, messages sent from the network, an internal database in the terminal or other external sources. 

Handover information will then have to include network and service availability in a given location. This raises 

the issue as to how the exact location information is acquired. In principle there are two ways of doing this: 

from mobile network positioning system or from a special positioning system integrated in the terminal like 

Galileo or GPS. Nevertheless, there might always be a case where positioning information can not obtained and 

the only solution is searching for network availability using the traditional scanning mode of the terminal. 

Finally, in the most general case the vertical handover might be necessary for different networks carrying the 

content in different format. For example, the content may be compressed to a different bitrate depending on the 

available network bandwidth. In this case even seamless handover may be possible when care is kept as to how 

the content is compressed and formatted. This case is illustrated in Fig. 24 where there is media content 

adaptation support which provides streams adapted to specific network requirements. 

tt.01.07 32

IST Project 


Contract no.: 

026902 



Fig. 24. Functions to Support Handover in Broadcast Network 

Moreover, Wi-Fi standards are getting larger and larger bandwidth and soon it will be possible to use Wi-Fi 

access points as cheap gap fillers for broadcast networks, for example inside buildings or in shadow areas as 

shown in Fig. 25. To do so, two options are possible: forwarding the entire TS stream or the lower IP layer only. 

Each of option has pros and cons. The advantage of forwarding the entire TS stream is clear in a vertical 

handover situation, because the synchronization of the TS stream is straight forward. However, it uses more 

bandwidth as the protocol stack is larger. (Ts over IP). Forwarding only the IP layer of the DVB-H network is 

lighter and makes more sense from a networking point of view because the protocol stack used by the 

transmission is optimized. However, the synchronisation is more complicated with DVB-H streams as DVB-H 

and Wi-Fi do not have the same execution layer (IP for Wi-Fi and TS for DVB-H). 

Fig. 25. Wi-Fi as DVB-H gap filler 

tt.01.07 33

IST Project 


Contract no.: 

026902 



4.2 Vertical handover execution layer 

Vertical Handover may require receiving content from several networks at the same time during handover 

execution to perform a soft content handover, were the change of network is done in a seamless way. Generally, 

support for soft content handover in IP can be done at three different levels. Each of those levels depends 

directly from the network environment configuration which effects the synchronization of content as shown in 

the Fig. 26. 

IP layer as in 1 

Streaming layer as in 2 

Media level (Video/Audio content) as in 3 

Basically, the more the network is managed, the lower the layer for vertical handover execution. 

Fig. 26. Different network environments 

tt.01.07 34

IST Project 


Contract no.: 

026902 



4.3 Review of the state of the art for vertical handover 

Apart of differences in network architectures described above an important topic is execution of handover. 

Vertical handover execution has been the topic of research over the last few years mostly in the context of 

cellular networks. The research in this area concentrates on handover decision algorithms and falls into four 

general approaches which can be applied to vertical handover and are named in the literature as: 

Rule based 

Client-controlled based 

Always Best Connected (ABC) 

Weighting 

Takeover 

The main idea behind the rule based algorithms is simple: each decision factor is set a Min and a Max threshold, 

if the limits are being reached, an action is decided. This idea is used in [14] and [15]. In [16], different decision 

factors for different applications are considered. The problem with this approach is that every time the user 

changes application, a vertical handover evaluation and a system discovery is triggered, consuming energy. The 

same approach is used by Nooman, et. al in [17]. The notion of Always Best Connected (ABC) was first 

described in [18] and enables users to maintain the best connection possible to the network that satisfies their 

application needs. The notion takes into account several factors that depend on both the user and the 

application. The ABC notion [19] has been used as the basis of other papers [20]. Most of the other papers deal 

with the same approach; many different deciding factors are given a weight and included in a mathematical 

equation for evaluation [19], [21]. In [22], a new takeover concept and protocol has been introduced which 

enable a neighbour node to process requests of a mobile node however, no technical explanation of the takeover 

process has been given. A new Pastry-based P2P (Peer-to-Peer) overlay network for supporting vertical 

handover in presented in [23] and [24] where P2P is used to quickly locate attachment points for mobile and to 

retrieve configuration and coverage information of those attachment points. 

In this document, the objective is to further enhance the previous ideas by introducing new concepts such as 

Universal Network and Service Directory and a Position Assisted Discovery System. 

4.4 Factors for a vertical handover decision 

There will be many factors impacting vertical handover decisions and algorithms. They are collected below: 

Network Characteristics 

o Technology 

o Availability 

o Bandwidth 

o Coverage 

o Latency 

o Packet loss 

o Power consumption 

o Moving speed 

o Price 

o Security 

o Protocols 

tt.01.07 35

IST Project 


Contract no.: 

026902 



Application Requirements 

o QoS (Real-Time or not) 

o Adaptability and Reconfigurability 

o Content 

o Security 

User Preferences 

o Single and Unique Identifier ( independent from network interface) 

o Personal Mobility 

o Cheapest Solution 

o Highest Bandwidth 

o Most Resistant to errors 

o First Available 

Mobile History of Usage 

o Point of interest 

o Application/Network combination 

User & Operators Agreements 

o Single Business Point (one contract for all ) 

o User -> Operator 

o Operator -> Operator 

As can be seen, considerable intelligence residing in the network or in the terminal, or in both, is required to 

accommodate these factors in the decision algorithms executing vertical handover. 

4.5 Decision algorithms 

Most of the algorithms for vertical handover found in the literature are trying to deal with subjective factors. 

Indeed, they assume that priorities are assigned in some ways to the factors presented above. Those factors are 

then evaluated by some algorithms and the handover decision is made based on the result. Since there is so 

much subjectivity in this decision, the general structure of handover algorithms will be outlined without 

considering the evaluation process for decision factors. 

A decision algorithm for vertical handover includes three steps: 

User or application profile selection, 

Network and system parameters evaluation 

Network selection 

Let’s suppose a user or an application has several profiles, i.e. cheapest, highest bandwidth etc. Each profile 

defines particular thresholds for every parameter, for example good, acceptable, and unacceptable range of 

values. Thus the first step is done as follows: 

tt.01.07 36

IST Project 


Contract no.: 

026902 



Check user profile 

define good, acceptable, unacceptable range of parameters 

Once every parameter is defined, they can easily be evaluated. For example, the user chooses the highest 

bandwidth profile. It is clear that the network with highest bandwidth will be selected first, but if that network 

has an unacceptable value of another parameter e.g. for packet-loss, as in Fig. 27, this network will be taken off 

the selection list and the network with the next highest bandwidth will be chosen. 

Fig. 27. Network parameters evaluation 

This step as can be summarized as: 

if PotentialNetwork has unacceptable value of a parameter 

then Drop 

if PotentialNetwork has all parameters good 

then put in the selection list 

Select network based on the highest value of the priority parameter 

This can also be done using membership functions of the factors as in [15]. Once the PotentialNetwork list 

contains only networks for which factors are acceptable or good, those factors are assigned priority which 

entirely depends on the user profile or the application requirements. In [20] for example, for a “quality first, 

price second” profile, important factors are given the following memberships coefficients: Wq = 0.8 , Wc = 0.6 

, Wo = 0.4 , Wt = 0.2 with Wq for quality factor, Wc for cost factor, Wo for operator factor and Wt for 

technology factor. Once those coefficients are added to each factor, the global impact can be evaluated. It is 

usually done with a simple weighted sum addition as follows: 

factor n x coefficient i 

Once this equation is calculated, the network with the highest result is selected. 

tt.01.07 37

IST Project 


Contract no.: 

026902 



4.6 Network Monitoring Algorithm 

Once the decision algorithm has selected a network for operation, it has to be monitored in a continuous way to 

make sure the quality of the access network remains good enough for the service delivery. 

Let’s first consider the case of Receive Diversity. The receiver can be switch on/off to diversity mode. Of 

course, when the diversity mode is switched on, the receiver consumes more battery. Thus we only enable the 

receive diversity mode when the level and the quality of the receive signal drop bellow a minimum threshold. 

This also prevents the ping-pong effect. We also turn off the receive diversity when transmit diversity is 

signalled in the network area table of the UNSD. The signalling of transmit diversity in the network area table is 

explained above or in more details in the PLUTO deliverable 2.1 – Services Scenario Specifications. 

This monitoring section can be represented as follow for Receive diversity: 

While AccessNetwork has acceptable value level and quality reception or Transmit Diversity enabled 

Switch OFF Receive Diversity 

if AccessNetwork has unacceptable value level and quality reception 

then Switch ON Receive Diversity 

While Receive Diversity ON and AccessNetwork has acceptable value level and quality reception 

keep Access Network 

else 

start Decision Algorithm 

tt.01.07 38

IST Project 


Contract no.: 

026902 



5 Integrated system for the network selection and 

handover in heterogeneous wireless network 

Vertical handover is part of larger problem of network selection. This is because, in heterogeneous networking, 

it is not obvious between which networks handover will be executed. There is thus a need for comprehensive 

information about networks and service availability. This information can be acquired in several ways as 

described earlier in this document but in any case it is a prerequisite for handover execution. For this reason, we 

consider here general flow diagrams for the network selection problem which includes handover as its part. The 

diagram shown in Fig. 28 is made from terminal point of view. The terminal has local information about user 

preferences and history of usage so ultimately the handover decision relies on the terminal side. The key block 

in Fig. 28 is marked as ‘Terminal & Applications Requirements”. In this block information about selected 

service, user profile and preferences and history of usage is evaluated. This gives the basis for the decision of 

specific network selection. The network manager and vertical handover manager execute this decision as 

presented previously in the algorithm decision (Chapter 4.5). 

Fig. 28. Terminal Architecture to Support Heterogeneous Network Selection 

Blocks marked in the flow diagram in Fig. 28 are considered in more detail next. In Fig. 29 network and 

services discovery flow is presented. This flow takes into account that three different discovery methods are 

possible. The active scanning mode is traditional sweeping over frequency bands until the broadcast is found. 

tt.01.07 39

IST Project 


Contract no.: 

026902 



This is very inconvenient because of slowness and it would be used for handover only in emergency cases. 

Second mode is based on Universal network and services directory available for the terminal as described 

earlier in this document. This can be downloaded from the network or preloaded in the terminal and can cover 

large areas. Third mode is based on positioning information available to the terminal e.g. from the built-in 

satellite location system. The satellite data can be integrated with the network and service coverage information 

giving highly exact data for handover. 

Fig. 29. Network and Services Discovery Architecture 

In Fig. 30 User Profile and Preferences diagram is shown. This includes network and service preferences which 

a user may select like cheapest, highest bandwidth, etc. 

tt.01.07 40

IST Project 


Contract no.: 

026902 



Fig. 30. User Profiles & Preferences 

In Fig. 31 Terminal and Application Requirements block is shown. On one hand battery and power 

consumption is important for the terminal performance and on the other hand such requirements as QoS, 

security and adaptability are important for the application point of view. These factors have to be weighted for 

making final decision about preferred network. 

Fig. 31. Terminal & Application Requirements 

In Fig. 32 factors considered for the network selection block are shown. This includes multitude of parameters 

which are required for providing sufficient network QoS plus aspects like pricing, security, power consumption. 

tt.01.07 41

IST Project 


Contract no.: 

026902 



Fig. 32. Factors for Network Selection 

In Fig. 33, network manager architecture is shown. In the flow diagram there is network monitoring node which 

has two branches: the QoS Agent branch is for terminal-based evaluation and the Operator trigger Agent is for 

evaluation information coming from the network. Information from these branches is used by Network 

Monitoring system for verification of network availability. 

tt.01.07 42

IST Project 


Contract no.: 

026902 



Fig. 33. Network Manager Architecture 

When the networks are verified for availability the network monitoring system signals readiness for vertical 

handover execution. Handover is executed by vertical handover manager shown in Fig. 34. Vertical handover 

manager has two branches depending on the way handover is executed. The first branch ‘Soft handover’ can be 

done if, during handover, the terminal can establish connection to two networks at the same time. This will 

allow soft transition between the networks. The second branch is ‘Hard handover’ in which only one network 

can be connected at a time. This requires of course abrupt switching between the networks and seamless 

handover can be guaranteed in this case only if there is proper buffering of data in the terminal. 

tt.01.07 43

IST Project 


Contract no.: 

026902 



Fig. 34. Vertical Handover Manager Architecture 

6 Prototype Application 

Fig. 35.Prototype application architecture 

Prototype application for heterogeneous networking is in development. The prototype’s architecture is 

described in the Fig. 35 and Fig. 36. It will make use of the ideas presented in this document for network and 

service discovery and will be used to show how DVB-H network and WLAN can be used in a heterogeneous 

environment. 

tt.01.07 44

IST Project 


Contract no.: 

026902 



Fig. 36. Prototype application for heterogeneous networking 

tt.01.07 45

IST Project 


Contract no.: 

026902 



7 Conclusion 

This document is a PLUTO deliverable concerning Network Selection and Handover Algorithms. In this 

document we presented a novel technique for network and service discovery in heterogeneous broadcast 

environment called UNSD for Universal Network and Service Discovery. It is an extension to the DVB-H ESG 

concept and can be applied both to mobile and stationary broadcast systems. Moreover, the UNSD is backward 

compatible with the original DVB-H ESG. The UNSD enables the unification of content, service and network 

description in a heterogeneous environment. It makes the discovery faster and easier as the UNSD allows 

acquiring full information about the entire broadcast network environment from a single instance of UNSD. We 

also proposed new methods for utilizing location and positioning information system by overlaying coverage 

and access information of networks on GeoMap data. Finally we designed algorithms (decision and manager) 

for making best used of the heterogeneous environment and to enable fast handover between broadcast 

networks. 

8 References 

[1] ETSI EN 302 304 V1.1.1 “ Digital Video Broadcasting (DVB); Transmission System for 

Handheld Terminals (DVB-H)” Nov. 2004 

[2] ETSI Standard: EN 300 744 V1.5.1, Digital Video Broadcasting (DVB); Framing structure, 

channel coding and modulation for digital terrestrial television” Nov 2004 

[3] ETSI standard (TS 102 427 and TS 102 428). 

[4] MediaFLO White paper - http://www.qualcomm.com/mediaflo/news/pdf/flo_whitepaper.pdf 

[5] 3GPP TS 23.246 - Multimedia Broadcast/Multicast Service (MBMS); Architecture and 

functional description 

[6] ETSI EN 300 468 V1.7.1 (2005-12) Digital Video Broadcasting (DVB); Specification for 

Service Information (SI) in DVB Systems 

[7] IP Datacast over DVB-H: Electronic Service Guide (ESG) – DVB Document A099 – November 

2005 

[8] ETSI EN 300 401 V1.4.1 (2006-06) Radio Broadcasting Systems; Digital Audio Broadcasting 

(DAB) to mobile, portable and fixed receivers 

[9] ETSI TS 102 818 V1.3.1 (2006-02) Digital Audio Broadcasting (DAB); Digital Radio Mondial 

(DRM); XML Specification for DAB Electronic Programme Guide (EPG) 

[10] Niri, S.G.; Tafazolli, R., "Position assisted handover algorithm for multi layer cell architecture," 

Vehicular Technology Conference, 1999. VTC 1999 - Fall. IEEE VTS 50th , vol.1, no.pp.569- 

572 vol.1, 1999 

[11] Jung Houn Yap; Xinjie Yang; Ghaheri-Niri, S.; Tafazolli, R., "Position assisted relaying and 

handover in hybrid ad hoc WCDMA cellular system," Personal, Indoor and Mobile Radio 

Communications, 2002. The 13th IEEE International Symposium on , vol.5, no.pp. 2194- 2198 

vol.5, 15-18 Sept. 2002 

[12] Geographical Positioning Extension for Ipv6, Nokia, White paper 

[13] Siebert, M.; Lott, M.; Schinnenburg, M.; Goebbels, S., "Hybrid information system [3G/WLAN 

intersystem cooperation]," Vehicular Technology Conference, 2004. VTC 2004-Spring. 2004 

IEEE 59th , vol.5, no.pp. 2982- 2986 Vol.5, 17-19 May 2004 

tt.01.07 46

IST Project 


Contract no.: 

026902 



[14] Sur, A.; Sicker, D.C., "Multi layer rules based framework for vertical handoff," Broadband 

Networks, 2005 2nd International Conference on , vol., no.pp. 571- 580 Vol. 1, 3-7 Oct. 2005 

[15] Qiang Guo; Jie Zhu; Xianghua Xu, "An adaptive multi-criteria vertical handoff decision 

algorithm for radio heterogeneous network," Communications, 2005. ICC 2005. 2005 IEEE 

International Conference on , vol.4, no.pp. 2769- 2773 Vol. 4, 16-20 May 2005 

[16] Wen-Tsuen Chen; Yen-Yuan Shu, "Active application oriented vertical handoff in nextgeneration 

wireless networks," Wireless Communications and Networking Conference, 2005 

IEEE , vol.3, no.pp. 1383- 1388 Vol. 3, 13-17 March 2005 

[17] Noonan, J.; Perry, P.; Murphy, J., "Client controlled network selection," 3G Mobile 

Communication Technologies, 2004. 3G 2004. Fifth IEE International Conference on , vol., 

no.pp. 543- 547, 2004 

[18] Gustafsson, E.; Jonsson, A., "Always best connected," Wireless Communications, IEEE [see also 

IEEE Personal Communications] , vol.10, no.1pp. 49- 55, Feb. 2003 

[19] Xing, B.; Nalini Venkatasubramanian, "Multi-constraint dynamic access selection in always best 

connected networks," Mobile and Ubiquitous Systems: Networking and Services, 2005. 

MobiQuitous 2005. The Second Annual International Conference on , vol., no.pp. 56- 64, 17-21 

July 2005 

[20] Qingyang Song; Jamalipour, A., "A network selection mechanism for next generation networks," 

Communications, 2005. ICC 2005. 2005 IEEE International Conference on , vol.2, no.pp. 1418- 

1422 Vol. 2, 16-20 May 2005 

[21] Adamopoulou, E.; Demestichas, K.; Koutsorodi, A.; Theologou, M., "Intelligent Access 

Network Selection in Heterogeneous Networks - Simulation Results," Wireless Communication 

Systems, 2005. 2nd International Symposium on , vol., no.pp. 279- 283, 5-7 Sept. 2005 

[22] Hyun-Ho Choi; Dong-Ho Cho, "Takeover: a new vertical handover concept for next-generation 

heterogeneous networks," Vehicular Technology Conference, 2005. VTC 2005-Spring. 2005 

IEEE 61st , vol.4, no.pp. 2225- 2229 Vol. 4, 30 May-1 June 2005 

[23] Hossfeld, T.; Oechsner, S.; Tutschku, K.; Andersen, F.-U.; Caviglione, L., "Supporting vertical 

handover by using a pastry peer-to-peer overlay network," Pervasive Computing and 

Communications Workshops, 2006. PerCom Workshops 2006. Fourth Annual IEEE International 

Conference on , vol., no.pp. 5 pp.-, 13-17 March 2006 

[24] Hossfeld, T.; Oechsner, S.; Tutschku, K., "Evaluation of a pastry-based P2P overlay for 

supporting vertical handover," Wireless Communications and Networking Conference, 2006. 

WCNC 2006. IEEE , vol.4, no.pp. 2291- 2296, 3-6 April 2006 

[25] Yang, X.D.; Song, Y.H.; Owens, T.J.; Cosmas, J.; Itagaki, T., “Seamless soft handover in DVB- 

H networks”, Softcom2004, Proceedings, 2004, Pages: 27-30 

[26] ETSI, EN 301 192, “Digital video broadcasting (DVB); DVB Specification for Data 

Broadcasting.” V1.4.1 (2004-11) 

[27] ETSI, TR 101 211, “Digital video broadcasting (DVB); Guidelines on Implementation and 

Usage of Service Information (SI).” V1.6.1 (2004-05) 

[28] Schwoerer, L.; Vesma, J., “Fast Scattered Pilot Synchronization for DVB-T and DVB-H”, Proc. 

8th International OFDM Workshop, Hamburg, Germany, September 2003 

[29] DVB Document A079 Rev.1, “IP Datacast over DVB-H: PSI/SI”, November 2005, available 

tt.01.07 47

IST Project 


Contract no.: 

026902 



from http://www.dvb-h-online.org/ 

[30] DVB Project, “Technical Requirements for IP Datacast”, DVB Project White Paper, TM3095R2 

(www.dvb.org ), 2004 

[31] Yang, X.D.; Song, Y.H.; Owens, T.J.; Cosmas, J.;Itagaki, T, “An Investigation and a Proposal 

for Handover Decision-making in DVB-H”, 14th IST Mobile & Wireless Communications 

Summit, Dresden, Germany, June 2005 

[32] Väre, J.; Puputti, M., “Soft handover in terrestrial broadcast networks”, MDM2004. 

[33] Hamara, A., “Considerations on Loss-Free Handover in IPDC over DVB-H Networks”, Master’s 

Thesis, University of Turku, March 2005. 

[34] May, G., “Loss-free Handover for IP Datacast over DVB-H Networks”, IEEE ISCE 2005, 

Macau, June 2005 

[35] Vare, J.; Hamara, A.; Kallio, J., “Approach for Improving Receiver Performance in Loss-free 

Handovers in DVB-H Networks”, Globecom2004, Volume 5, 2005, Pages: 3326-3331 

[36] Schwoerer, L., “Fast Pilot Synchronization Schemes for DVB-H”, Proceedings of the 4th 

IASTED International Multi-Conference on Wireless and Optical Communications, Banff, 

Canada, July 2004 

[37] Yang, X., “Handover Issues in DVB-H and in Converged DVB-H/UMTS Networks”, Doctoral 

thesis, Brunel University, January 2006 

[38] May, G.; Buburuzan, T.; and Unger, P., “A Mobility Support Architecture for DVB-H / IP 

Datacast Terminals based on IEEE 802.21”, 56th Annual IEEE Broadcast Symposium 2006 

8.1 Other References 

[39] Considerations of multiple network interface for a mobile node Yong-Geun Hong; Jung-Soo 

Park; Hyoung-Jun Kim; Advanced Communication Technology, 2006. ICACT 2006. The 8th 

International Conference 

[40] Dynamic network interface selection in multihomed mobile hosts Ylitalo, J.; Jokikyyny, T.; 

Kauppinen, T.; Tuominen, A.J.; Laine, J.; System Sciences, 2003. Proceedings of the 36th 

Annual Hawaii International Conference 

[41] Dynamic Reconfiguration of Real-Time Network Interfaces : Vonnahme, E.; Griese, G.; 

Porrmann, M.; Ruckert, U., Parallel Computing in Electrical Engineering, 2004. PARLEC 2004. 

International Conference on , vol., no.pp. 376- 379, 7-10 Sept. 2004 

[42] Minji Nam; Nakjung Choi; Yongho Seok; Yanghee Choi, "WISE: energy-efficient interface 

selection on vertical handoff between 3G networks and WLANs," Personal, Indoor and Mobile 

Radio Communications, 2004. PIMRC 2004. 15th IEEE International Symposium on , vol.1, 

no.pp. 692- 698 Vol.1, 5-8 Sept. 2004 

[43] Hongwei Liao ; Ling Tie; Zhao Du, "A Vertical Handover Decision Algorithm Based on Fuzzy 

Control Theory," Computer and Computational Sciences, 2006. IMSCCS '06. First International 

Multi-Symposiums on , vol.2, no.pp. 309- 313, 20-24 April 2006 

[44] EunHae Kim; SuJung Yu; SungMin Yoon; JooSeok Song, "An Efficient Paging Message 

Scheme for Vertical Handoff Decision in Convergence of Telecommunication and Broadcasting," 

Broadband Convergence Networks, 2006. BcN 2006. The 1st International Workshop on , vol., 

tt.01.07 48

IST Project 


Contract no.: 

026902 



no.pp. 1- 5, 07-07 April 2006 

[45] Indulska, J.; Balasubramaniam, S., "Context-aware vertical handovers between WLAN and 3G 

networks," Vehicular Technology Conference, 2004. VTC 2004-Spring. 2004 IEEE 59th , vol.5, 

no.pp. 3019- 3023 Vol.5, 17-19 May 2004 

[46] Luan Huang; Chew, K.A.; Tafazolli, R., "Efficient multimedia content delivery over cooperative 

3G and broadcasting networks," Personal, Indoor and Mobile Radio Communications, 2005. 

PIMRC 2005. IEEE 16th International Symposium on , vol.4, no.pp. 2279- 2283 Vol. 4, 11-14 

Sept. 2005 

[47] Chebbine, S.; Chebbine, M.T.; Obaid, A.; Johnston, R., "Framework architecture for Internet 

content adaptation system and vertical handover management on 4G networks," Wireless 

Telecommunications Symposium, 2005 , vol., no.pp. 34- 44, April 28-30, 2005 

[48] Luan Huang; Kar Ann Chew; Tafazolli, R., "Network selection for one-to-many services in 3Gbroadcasting 

cooperative networks," Vehicular Technology Conference, 2005. VTC 2005-Spring. 

2005 IEEE 61st , vol.5, no.pp. 2999- 3003 Vol. 5, 30 May-1 June 2005 

[49] Li Ma; Fei Yu; Leung, V.C.M.; Randhawa, T., "A new method to support UMTS/WLAN 

vertical handover using SCTP," Wireless Communications, IEEE [see also IEEE Personal 

Communications] , vol.11, no.4pp. 44- 51, Aug. 2004 

[50] Yana Bi; Jianwen Huang; Iver, P.; Mei Song; Song, J., "An integrated IP-layer handover solution 

for next generation IP-based wireless network," Vehicular Technology Conference, 2004. 

VTC2004-Fall. 2004 IEEE 60th , vol.6, no.pp. 3950- 3954 Vol. 6, 26-29 Sept. 2004 

[51] Vare, J.; Hamara, A.; Kallio, J., "Approach for improving receiver performance in loss-free 

handovers in DVB-H networks," Global Telecommunications Conference, 2004. GLOBECOM 

'04. IEEE , vol.5, no.pp. 3326- 3331 Vol.5, 29 Nov.-3 Dec. 2004 

[52] Enhanced Handover Performance in Cellular Systems based on Position Location of Mobile 

Terminals 

[53] May, G., "Loss-free handover for IP datacast over DVB-H networks," Consumer Electronics, 

2005. (ISCE 2005). Proceedings of the Ninth International Symposium on , vol., no.pp. 203- 208, 

14-16 June 2005 

[54] BenHui, http://www.benhui.net/. [14] M. Ylianttila, "Vertical Handoff and Mobility - System. 

Architecture and Transition Analysis", Doctoral thesis 

[55] J. Luo, M. Dillinger, E. Schulz, and Z. Dawy, "Probability Estimation for Soft Handover in 

WCDMA," in IEEE 3Gwireless 2000, San Francisco, June 2000. 

[56] X.D.Yang, Y.H.Song, T.J. Owens, J.Cosmas, T.Itagaki, "An Investigation and a Proposal for 

Handover Decision-making in DVB-H", IST Mobile & Wireless Communications Summit 2005 , 

Dresden, Germany, June 2005 

[57] Vare, J.; Hamara, A.; Kallio, J., "Approach for improving receiver performance in loss-free 

handovers in DVB-H networks," Global Telecommunications Conference, 2004. GLOBECOM 

'04. IEEE , vol.5, no.pp. 3326- 3331 Vol.5, 29 Nov.-3 Dec. 2004 

[58] Beyond 3G: Fourth Generation. Wireless Networks. Pedro M. Ruiz. Agora Systems SA. II 

Jornadas de Internet NG. Madrid, 22. nd. October 2002 

[59] I. Miloucheva, "Context management for efficient mobile multicast services", International 

workshop on Context in Mobile HCI (Human Computer Interfaces) in conjunction with 

tt.01.07 49

IST Project 


Contract no.: 

026902 



MobileHCI'05 Conference, Salzburg, September 19, 2005 

[60] Daniel Negru, Yassine Hadjadj Aoul, Ahmed Mehaoua, Anastasios Kourtis "Ipv6 over DVB-T: 

Mobility issues and challenges," in proc. of het-net 2004, the 2nd international working 

conference on the performance modeling and evaluation of heterogeneous networks, ilkey, west 

yorkshire, u.k., july 26th, 2004 

[61] Intersystem Soft Handover for Converged DVB-H and UMTS Networks 

[62] May, G., "Loss-free handover for IP datacast over DVB-H networks," Consumer Electronics, 

2005. (ISCE 2005). Proceedings of the Ninth International Symposium on , vol., no.pp. 203- 208, 

14-16 June 2005 

[63] Yang, X.D.; Song, Y.H.; Owens, T.J.; Cosmas, J.; Itagaki, T., "Performance analysis of time 

slicing in DVB-H," Mobile Future, 2004 and the Symposium on Trends in Communications. 

SympoTIC '04. Joint IST Workshop on , vol., no.pp. 183- 186, 24-26 Oct. 2004 

[64] Yang, X.D.; Song, Y.H.; Owens, T.J.; Cosmas, J.; Itagaki, T., "Performance analysis of the 

OFDM scheme in DVB-T," Emerging Technologies: Frontiers of Mobile and Wireless 

Communication, 2004. Proceedings of the IEEE 6th Circuits and Systems Symposium on , vol.2, 

no.pp. 489- 492 Vol.2, 31 May-2 June 2004 

[65] Resource Management over Interworking of 3G and Digital Broadcasting Networks : Huang, 

L,Chew, K. A. and Tafazolli, R Ninth IFIP/IEEE International Symposium on Integrated 

Network Management (IM 2005),Nice, France. 15-19 May 2005. 

[66] Sattari, N.; Pangalos, P.; Aghvami, H., "Seamless handover between WLAN and UMTS," 

Vehicular Technology Conference, 2004. VTC 2004-Spring. 2004 IEEE 59th , vol.5, no.pp. 

3035- 3038 Vol.5, 17-19 May 2004 

[67] X.D.Yang, Y.H.Song, T.J. Owens, J.Cosmas, T.Itagaki,"Seamless Soft Handover in DVB-H" in 

IEEE International Conference on Software, Telecommunications and Computer Networks, Split 

(Croatia), Dubrovnik (Croatia), Venice (Italy), October, 2 

[68] Semantic design patterns for personalization of DVB-H multimedia broadcast 

[69] Soft Handover Issues in Radio Resource Management for 3G WCDMA Networks 

[70] Ladebusch, U.; Liss, C.A., "Terrestrial DVB (DVB-T): a broadcast technology for stationary 

portable and mobile use," Proceedings of the IEEE , vol.94, no.1pp. 183- 193, Jan. 2006 

[71] The Handheld Software Platform (HSP)A software platform for DVB-H and IP Datacast 

[72] Faria, G.; Henriksson, J.A.; Stare, E.; Talmola, P., "DVB-H: digital broadcast services to 

handheld devices," Proceedings of the IEEE , vol.94, no.1pp. 194- 209, Jan. 2006 

[73] A Handover Approach to DVB-H Service," IEEE International Conference on Multimedia & 

Expo (ICME 2006), July 9-12, 2006, Toronto, Canada, pp.629-6 

[74] Vare, J.; Puputti, M., "Soft handover in terrestrial broadcast networks," Mobile Data 

Management, 2004. Proceedings. 2004 IEEE International Conference on , vol., no.pp. 236- 242, 

2004 

[75] Joyce, R.M.; Griparis, T.; Osborne, I.J.; Graves, B.; Lee, T.M., "Soft handover gain 

measurements and optimisation of a WCDMA network," 3G Mobile Communication 

Technologies, 2004. 3G 2004. Fifth IEE International Conference on , vol., no.pp. 659- 663, 2004 

[76] Frattasi, S.; Fathi, H.; Fitzek, F.H.P.; Prasad, R.; Katz, M.D., "Defining 4G technology from the 

tt.01.07 50

IST Project 


Contract no.: 

026902 



users perspective," Network, IEEE , vol.20, no.1pp. 35- 41, Jan.-Feb. 2006 

[77] Ganchev, I.; O'Droma, M.; Chaouchi, H.; Armuelles, I.; Siebert, M.; Houssos, N., "Requirements 

for an integrated system and service 4G architecture," Vehicular Technology Conference, 2004. 

VTC 2004-Spring. 2004 IEEE 59th , vol.5, no.pp. 3029- 3034 Vol.5, 17-19 May 2004 

[78] Suk Yu Hui; Kai Hau Yeung, "Challenges in the migration to 4G mobile systems," 

Communications Magazine, IEEE , vol.41, no.12pp. 54- 59, Dec. 2003 

[79] Lazar, S.; Sidhu, D.; Kodeswaran, S.; Varadharaj, R., "ATM network discovery using mobile 

agents," Local Computer Networks, 1999. LCN '99. Conference on , vol., no.pp.98-105, Oct 1999 

[80] Adamopoulou, E.; Demestichas, K.; Koutsorodi, A.; Theologou, M., "Intelligent Access 

Network Selection in Heterogeneous Networks - Simulation Results," Wireless Communication 

Systems, 2005. 2nd International Symposium on , vol., no.pp. 279- 283, 5-7 Sept. 2005 

[81] M. Liebsch, A. Singh (editors), H. Chaskar, D. Funato, E. Shim, “ The Candidate Access Router 

Discovery Protocol”, IETF draft-ieft-seamoby-card-protocol-08.txt, work in progress. 

[82] Ilka Miloucheva, “Context Management for Efficient Mobile Multicast Services” 

[83] Kenneth L. Clarkson and John D. Hobby. A Model of Coverage Probability under Shadow 

Fading, August 25, 2003. 

[84] Ligeti, A., "Coverage probability estimation in single frequency networks in presence of 

correlated useful and interfering components," Vehicular Technology Conference, 1999. VTC 

1999 - Fall. IEEE VTS 50th , vol.4, no.pp.2408-2412 vol.4, 1999 

[85] ETSI TS 102 822-2 V1.3.1 (2006-01) Broadcast and On-line Services: Search, select, and 

rightful use of content on personal storage systems ("TV-Anytime"); Part 2: System description 

tt.01.07 51

Deliverable 2.2 - the School of Engineering and Design - Brunel ...

Create successful ePaper yourself

Delete template?

Save as template?