Note: Descriptions are shown in the official language in which they were submitted.
CA 02446852 2003-11-13
TELEVISION DELIVERY SYSTEM
This is a divisional application of Canadian Patent
Application Serial No. 2,334,203 filed Tune 3, 1999.
TPChnic~~l FieZ.d
This invention relates generally to a delivery sy:sLem io~r
digital television and more particularly to a system and
method ~cr the delivery and end to end management of
inte~~active television and integrated Web sevzvices.
Bar. kgz-mind Art
Witx: tae proliferation of TV broadcast providers delivering
reguiaz- programming as well as specialty services, such as
pay per view and first run movies, TV viewers are frequently
faced with scheduling problems in order to vie~~~ their
favorite programs. The scheduling problem is even more
severe in a typical 1-v~ousehold having one television with
several potential viewers each having tlze:ir own viewing
0 preferences.
Tv broadcasts are currently delivered though service
providers such as cable companies, and satellite operators
and, of course, direct broadcast reception via traditional
antennas and rabbit ears. Conventional cable service
requires the installation of a dedicated cable to the
subscriber's residence. Satellite broadcast service requires
that the user have a satellite dish located on or somewhere
close to their residence. Antennas and rabbit ears are
30 generally limited to the reception of local programming.
Additionally, prograrl delivery via all of these services is
at the convenience o1: the service provider or broadcaster
and, hence, the user or subscriber must arrange his or her
schedule to coincide with program availability.
CA 02446852 2003-11-13
It is well l~:nown thav~ the purchase of personal computers by
homeowners has increased dramatically in recent years.
Typically, these computers are used for word processing,
accour_ting and other record keeping purposes. Most of these
computers also have modems for connection to the Internet
through an Internet Service Provider utilizing conventional
telephone service. Frequently, however, these rradems have a
low baud rate that m,ar;.es downloading of information,
t0 particularly graphics, unacceptable.
D~.sc~~osure of the Invention
In view of the foregoing there is a requirement to provide
an improved method of delivering broadcast television a.nd
providing Internet access to subscribers of such services.
The present invention relates to a system that provides the
hardware and the necessary software for a broadcast
provider, u.Thich may be a telephone company, to offer a wide
20 range of managed broadcast television services to consumers.
In accordance with various aspects of the invention these
services include: end to end network administration;
Interactive Program Guide (IPG) functionality offering self-
serve pay-per-view, ~Tideo on demand and Internet access;
customer profile management; billing and payment
capabilities; consumer arranged service options; channel
packaging; user activity collection; statistics and
reporting; video games; basic television; and VCR
functionality including self-serve viewing of previously
30 broadcast programs.
Through the present invention broadcast providers such as
telephone companies are afforded the opportunity to compete
CA 02446852 2003-11-13
successfully in the b~_oadcast TV marJtet . With the
combination of high speed, TP capable technologies, (for
example, ATM, xDSL, NtI?EG-1 and MPEG-2, and IP-Multicasting;
tied together v~ith the systems of the present invention
telephone companies no longer need to want Lar Lutu~:e.
technalogy solutions.
Therefore in accordance with a first aspect of the invent10I1
there is provided a s~rstem for the delivery of broadcast
television from a broadcast provider Lo a subscriber via t:
Internet Protocol (IPj, the system comprising: means at the
broadcast provider's location for_ retrieving broadcast
television signals; means at the broadcast provider's
location fo~~ conf:igu?-:ing the television :~ignal.~~ into IP
format for transmission over a broadband backbone networ't;
and a management sysi~;~m for managing ~ subscriber's access
to the television signals.
In a preferred embodiment the system e-mploys an interactive
program guide (TPG} that offers a sub~cr~.ber access to
multiple scheduling and servicing functions including
browsing and searching using a menu driven, 'point and
click' process.
Further, the system contemplates the use of an IP Multicast
protocol for TV broadcast and near video on demand services.
Additionally, an IP Unicast protocol may be used for video
on demand service.
Significantly, all of these features are delivered via IP
and ATM technologies using a single point of access rather
than a combination of delivery systems such as satellite and
cable.
J
CA 02446852 2003-11-13
The present system makes use of a decoder at the
subscriber's location. to convert the IP format into a form
fer viewing on a television or computer monitor. The decoder
for a television is incorporated into a set top bo}:
associated with the T'V ~~lhile the decoder for the computer
monitor will typically be installed in the PC.
The management aspects of the invention result in the
:0 ab~~.lity to remotely manage client devices (for example set
top boxes) at the sutbscriber's locat~OIl. Such management
include~~ remote diagnostics and notification of data
updates.
In accord~:nce with a second aspect of the invention there is
provided a method of delivering TV broadcast from a
broadcast provider tc a subscriber over a broadband, IP
enabled neturork. The method comprises: obtaining broadcast
TV signals for the broadcast provider; converting the
20 broadcast signals to IP format; transmitting the converted
signals over the network; and providing a management
function to manage a subscriber's access to broadcast
signals .
In a preferred embodiment the converted signals are in a
MPEG encoded format.
Brief Descriz~tion of the Drawings
30 The invention will now be described in greater detail with
reverence to the atta=shed drawings wherein:
Figure 1 is a high level diagram of a video broadcast system
in accordance with one aspect of the present invention;
4
CA 02446852 2003-11-13
Figua.-e 2 is a more detailed diagram of the system of Figure
z;
Figure 3 is an architectural block diagram of network
elements;
:=iguz-e ~' illustrate the operational aspects of the Digital
TV Manager;
Figure 5 is a layered diagram illustrating t;he rel~~tionshio
of system components;
Figure 6 is a depiction of one example of an interactive
program guide (IPG);
Figure 7 illustrates an exemplary information banner
appearing in the IPG;
Figure 8 illustrates an alternative IPG;
Figure 9 is a block diagram of. the pant TV c~onccpt according
to one aspect of the invention; and
Figure ?0 illustrates a system for concurrent transmis~ior.
of P~IPEG-1 and MPEG-2 encoded signals.
F~est Mode for. Car_r.~ririg out the Ynvention
Figure 1 is a high level diagram of the basic elements of a
video delivery system. Video source 12 retrieves signals for
broadcast from various sources such as satellites. These
signals are delivered to a videowencoder l4 via NTSC (PAL,
SECAM) video signals where they are converted to an IP
Multicast form and subsectuently sent out by a service
provider 1G over a broadcast network to a Digital Subscriber
Line Access Multiplexer (DSLAM) 18 vrhich might be located in
a telephone company central office. The IP i~Iulticast signal
from the DSLAM 18 is delivered to a subscribers residence
over an xDSL link sur_h as an Asymmetric Digital Subscriber
Line (ADSL) where it is received by an F~SL modem 20 and
delivered to a client server such as a Set Top Box (STB) 22.
5
CA 02446852 2003-11-13
FiQUre 2 is a slightly more detailed representation of. the
bask concept of the present invention. As shourn the video
source 12 is a satellite located at head-end 24, which may
be operated 1~j~ a bro~udcast provide, such as a telephone
company or other service provider. Head end 2~ interfaces
with a broadband netcao~-k 26 through a IP multicast muter
23. As noted the broadband network is IP compatible (for
example, IP Multicast) and has sufficient bandvridth capacity
;0 to transport encoded video signals. A subscriber to the
broadcast service has access to the network via a broadband
link: such as a Digital Subscriber Line (DSL), for example
Asymmetric Digital Subscriber Line (ADSL), Hybrid Fiber Coax
(HFC) Fiber to the Curb (FTTC) or wireless service such as
Local Multipoint Distribution System (LMDS}. ADSL is of
particular significance because it allows a broadcast
provider to deliver programming to residential communities
over existing copper wire without having to delay
introduction of the services until the ether access
20 technologies become widely available.
The subscriber can access the TV broadcast with either a
computer 30 having an associated CPU or a television 32 with
a set top bor: 22. The set top box 22 in this implementation
includes decoding circuitry for decoding MPEG-1 and/or MPEG-
2 as well as IP Multic ast. The computer 30 may be equipped
with an appropriate MhEG card or appropriate software if the
broadcast is to be viewed or, a computer rnonit~or. Set top box
22 may be activated by an interface unit such as a lcey board
30 or remote device 23.
The broadcast provider as shown in Figures 1 and 2 is able
to access television broadcast signals from various sources
6
CA 02446852 2003-11-13
such as satellite l2, off-air broadcast or a storage medium
providing movies or tl~ie like. The service prov~.der encodes
the broadcast signal OMPEG) and makes it available tc
service subscr fibers through the broadband net.worl: 2G usincr
the InterT~et protocol.
Also shown in Figure 2 is the Digital TV Manager (DTVM) 40
that provides end to e:nd n;anagement of service= and
resources of the integrated broadcast delivery system. D'iVM
40 is linked to the ne:tworh. 2~ via a transport muter X12.
Figure 3 shows in greater detail the architectL:ral
configuration including the home or customer equipment, the
broadband IP networ)> and services and the DT~-'M services. In
Figure 3 a second aspect of the deliverable a>ervices, i.e.
Internet access is shown.
For standard broadcast. signals and pay per vievt (PPV) or
near video on demand (NVOD) services a multicast IP protocol
2o is used in order to make efficient use of bandc~,ridth. ~v"ith
this protocol numerous subscribers can have access to a
program at the same time. For true video on demand service,
however a unicast IP protocol is used.
Figure 3 illustrates ~n block diagram format the various
elements of a broadcast delivery system according to the
invention. As shown, t:he home appliance sect~~.on includes a
personal computer 30 and TV with set top boy 22. Access to
the network is through a xDSL access element sucO as a~~ ADSL
30 Transmission Unit (ATIJ) 20. The broadband IP Network and
Services section includes access muter 18 and the transport
network 'cloud° 26. The transport network 2~ has access to
the various broadcast features such as Video on Demand (VOD)
7
CA 02446852 2003-11-13
50 , Near Video on DE:rnand (NVOD) 52 and e-mail 54 arid Web
access through the Ieiternet 56.
The DTVM section 40 contains the multiple service features
available to a subscriber of the system. These include but
are not limited to ~.lling and reporting, Interactive
Program Guide (IPG) access, connection and channel packaging
sertrice a:~d informati.on banner service.
Figure 4 is an operational view of the system shown in
Figure 3. The Digital Subscriber Lire Access Multiplexes
(DS'~AM) I~ at the edge of the high speed TP network is a
network device which may be located at a telephone company
central office. The DSLA_M enables a telephone company to
provide subscribers with xDSL, such as ADSL, technology and
to connect the subscriber to a Last bac'..bone such as an ATM
net~raork. The ATM network routes the various broadcast
services, previously mentioned, to the DSL~AM which, in turn
makes them accessible to subscribers via their computer 30
and/or set top box 22.
Figure 5 shows in a layer format the relationship between
service and resource providers respecting the overall TV
broadcast delivery Lystem. At the bottom layer (layer 1) are
the equipment and appliance suppliers such as set top box
and computer suppliers, etc. The second layer (layer 2)
represents the service provider such as a Telco who make
available the IP and other protocols necessary to transport
the services and features between the provider and
subscr fiber . The thixd layer ( layer 3 ) ir~c 1 udes the
functionality of the DTVM according to the present
invention. As indicated these include Customer and Admin
s
CA 02446852 2003-11-13
services, Reporting and Billing services and IPG and Browses
clients.
The DTVM allows Service Providers such as Telcos to offer az:
alte~~native to cable TV as presently Jczzown. '.Chzwyh the L7'('VM
interactive TV carp be integrated with Web Browsing, Web-
based mail, VOD and pay per view services. Customized
services including self-subscription is offered through the
IPG. The IPG has access to TV program scheduling information
such as TVGuide and mai:es this information available in'
electronic form for use by the subscriber. The IPG also
provides access to VGh, NVOD, Internet programming as well
as video and audio coz~ter~t . The subscriber successes the IPG
through the set top,bo~~: or through the computer software. In
the set top box. implernentation some memory may be available
locally for storing specific information, or alternatively,
the entire IPG is maintained in the network. The subscriber
typically has a remote control or keyboard for interfacing
with the IPG displayed on the television or computer
?o monitor. Scheduling information may be in a arid format o:.-
in time slot form as vaill be discussed later. In any event
the interactive nature of the IPG gives a subscriber control
over many aspects of t:he broadcast system. Ef:amples of IPG
format and functional=_ty are shown in Figures 6, 7 and 8.
The DTVM in car_junction with IPG provides a subscriber with
the ability to channel_ browse for TV program: and Web sites.
A seven day channel l~tneup with scheduled automatic refresh
is provided. The IPG client softT,aare is automatically
updated by the system at regular intervals. Figure 6 shows
30 one example of an IPG menu showing channel, time and
schedule content information. Clicking on a highlighted
selection displays a brief information banner with relevant
data concerning program content and time remaining. This
9
CA 02446852 2003-11-13
banner can be expanded as shown in Figure 7 to provide more
detail if available. Figure 8 illustrates a second example
of an IPG including a program detail banner containing
information representing a highlighted channel.
As stated above the IPG is client software that operates in,
for example, both a windows and set top environment and
provides a link to the client MPEG-1/MPEG-2 decoder and the
client conditional access module. This software also
t0 provides the user with access to all broadcast content on
the broadband multicast IP network as well as supporting
services (i.e. subscription management).
Looking at Figure 5., the IPG data delivery block 60 relates
to server software which provides the broadcast content
schedules, previously mentioned, to the client IPG software
based on the broadcast; provider, customer location and
customer profile. The server softc~aare has the responsibility
to extract broadcast content schedules from various existing
2o data sources.
The live MPEG encoder 62 is a component which provides real-
time MPEG--1 or MPEG-2 encoding. It encodes analog video and
audio inputs to produce MPEG-i system at MPEG-2, Transport
Streams for delivery via an IP multicast network.
The Banner Server 64 is server software 'which will provide
scheduled ad insertion into the client IPG bG.sed on time of
day, broadcast provider, the customer location and customer_
30 profile.
CA 02446852 2003-11-13
The Near Videe-on-Demand (N~IOD) Server 66 is a component
that provides scheduled managed delivery of pre-z-ecorded
material via an IP multicast network.
'The Customer profile rr,anagement systern/subscript;.on
management system 68 His software to store and track customer
preferences, usage patterns, billing status, mailing
addresses, client devices, service subscription, etc. It
also provides the cor« data for many of the others
components.
The Notifier and Indica;_ar block 70 is softcaar;~ that gives
the system the abilit;r co script, send and displ~:y on the
client server notices and messages such as calling ID and
messages waiting.
The Video-on-Demand (VOD) Server 72 is a componer_t which
will provide the client access to VOD playback using
interactive VCR controls for optimal contro l It provides
all the tools necessa~.-y to store, manage and deliver real-
time, full-screen video and audio content.
A Conditional Access System (not shown) cons__sts of both a
source and destination module and is responsible for the
encryption, as necessary, of data between the source and
destination to protect: copyrights.
The consumer Services section 80 includes such functionality
as conr_ection services, self ordering services and
provisioning.
CA 02446852 2003-11-13
Administration services section 82 includes the importation
of IPG data on a scheduled basis. Channel packaging which
provides a consumex- with the ability to manage their
subscription (including self-service; system is a user
interface to allow the end user to viectr add and delete
channels from their service subscription and check their
usage and pav bills.
The Report anti Billing Service system 8« provides integrated
lc) billing and repo~~ting services which enables a subscriber to
dynamically monitor service usage ardd to .'peep track of
service costs on a self-serve b~isis.
The Database block.8~ represents software to provide ar_
information database of broadcast content unique to the
broadcast dist:ributio.n system provider t:o feed the IPG
database.
The Operational Servi~::es compor_ent or Errd to Dnd network.
20 management system 88 :has management softv~are to integrate
the control of all the broadcast distribution system
components into a networked management framework, including
quality of service management and usage collection.
The interactive nature of the services provided by the
broadcast s~rstem of t:ne present invention gi~Jes a subscriber
considerably more options as to what programs may be watched
and when they may be ~;ri~wed. Figure 6 provides an elementary
e::ample ot= an interac'~ive broadcast schedule. As shoum,
.0 program listings for a range of TV channels for a particular
time period i~ given. R~ith a listing such as this displayed
on a TV monitor a vio~~rer can scan the list, click on a
desired program and the television will tune in to selected
I2
CA 02446852 2003-11-13
channel. Figure F3 illustrates another version of a program
guide l~::oum as a preview IPG according to the present
invention, Electronic program guides per se are IiIlOWli and it
will be apparent to one skilled in the art that a form of
chart best suited for the viewer's purpose can be~~ de~~~~.~~rled.
The following description identifies some of the feauures
available through the system of the present invention.
I0 The system includes all the necessary software fo?- a
broadcast provider to offer broadcast television over
Internet Protocol (IP), including IP multicast anc3 unicast,
which allo~.~ channel browsing by selecting IP multicast
streams. IP multicast is characterized by the sending out of
data to distributed servers on a multicast backbor~c network.
For large amounts of data (including video transmissions),
IP multicast is more efficient than normal Internet unicast
transmissions because the server can broadcast a message to
many recipients simultaneously. Unlike traditional Internet
20 traffic that requires separate connections v~or each source-
destination pair, TP multicasting allours many recipients to
share the same source. This means that just one set of
packets is transmitted for all the destinations.
The system has the aaility to broadcast television digital
signals over existing copper wire (DSL tecr~nologies), or any
other broadband IP enabled network including LMDS and Hybrid
Fiber Coax (HFC). According to the present invention tl;e
system has the ability to script, send and displ,~r messages
3o to a client device screen in real time. Me:chanismN used to
accomplish this include IP multicast and/or SNMP. Messages
may include icons that relate to the message available to be
viewed. The user can press a key on a remote device to
I3
CA 02446852 2003-11-13
retrieve the corresponding message via SNMP or Unicast. The
messages can include, for example, calling line ID
notifications and message waiting indicators.
With this system the automatic service provisioning of a
television channel online is possible. This eliminates the
need for se~-~~ice pro,rider or Telco trucl~a to go to the
consumer' ~ locat20T: 'to add or remove near channel oftcrings .
The systerr~ allows consumers to change channel/i-ackage
information online without the need for equipment and/or
personnel's physical presence to be dispatched to a
cor_sumer~s home to connect or disconnect the appropriate
channels. Additionally, the DTVM allows management,
remotely, of the client devices including the ability to
query and reset key indicators such as system Health
indicators, e.g. MPE:~ diagnosis, application and network
status, e.g. current viewed channel, current NFS server, and
re-initialize the client device. This may be accomplished
by, for example, a SNMP protocol. Further, the DVTM offers
?0 the ability to remotely inform the client device (e. g. STE)
that new data and/ar software is available and should be
retrieved. This may be accomplished by, for example, IP
multicast and/or SNMP.
household consumers are able to self-service their accounts,
add and remove channels, view and/or pay broadcast
provider's real-time and end-of-period bill summaries
online.
3U The interactive electronic program guide allows access to
such enhanced video features as Video on Demand (VOD) or
Near Video on Demand (N'VOD). VOD is an umbrella term for a
wide set of technologies that enables individuals to select
1~
CA 02446852 2003-11-13
videos from a central server for viewing on a television. or
computer screen. Additionally, the system affords a service
provident to make available games on demand. 'This service is
simila r to vOD wherein Nintendo-type games are available fc~
access by subscribers. A consumer can choose a game L~rmn tia:v
IPG or using a Web user interface. A subscriber is charged
per game/time played.
It is also within the scope of the invention for a service
provider to assign a URL to a channel mut:vber. A URL is an
address used co enable an Internet browser program to find a
particular Internet resource. Using this feature a
subscriber could view a URL channel on t'ne IPG slinllar to a
video channel. Customers would be able to scan through URL
channels and select a desired URL by entering the associated
numbers from the remote device in the same way as video
channels are selected. Going through a URL channel would
switch the client device (STB, for example) to a web browser
and thereby access a selected web page. In the same way the
system can alloy for channel hotlinks. While watching a
program or vahen a program is highlighted on the IPG, tllE'
user can operate a remote entry device to activate a
transfer to a dynamic web page. The web page could disp:Lay,
for example, information on the program, on the channel, or
on the subject matter currently being shown. The system
could also provide links to related topics.
The system acts as a virtual VCR, with the ability to
schedule, record and playback various programs in the
network. It is anticipated that one or more server's in the
network will maintain a recording of recently aired programs
for access by a user at some finite time after the program
was initially shown. Thus the system acts as a backup video
IS
CA 02446852 2003-11-13
source, enabling a viewer to retrieve previously aired
programs for viewing at their choice of times. Tn the PC
i:r:plementation the PC. hard drive can optionally serve as a
storage medium for pz-eviously aired programs. The system
v~iil also ~zl?.ow a cu~~tome?- to view a list of programs
recorded, watch one of the programs from the list, set up
the system to remoteZ.y record programming on a networ)~
storage device either in real time or in advance. A Remote
storage device and associated software effectively records
to only one copy of a tagged program far access by multiple
users later. ~igure 9 shows the past TV and network VCR
aspects of tl~c invention. Past TV uses one or more video
servers 90 in the network that continuously stores the iP
Multicast TV content from a number of previous days (the
number is application specific). The stored data is indexed
and made available via the HTML based IPG through the STB.
Netvlork VCR uses the video server 90 to provide a subscriber
with all the feature; of a VCR plus random access. The
server 90 stores the multiple programs from the IP mult:icast
20 TV content, indexes them and makes them available to the
subscriber va the IPG.
The system acts as an intelligent agent providing the
ability to rEmind a viewer of an upcoming program, enabling
recommendations by the system to consumers about program
content bases on usez~ criteria, system gathered data, and/or
an outside source, such as TV Guide, movie critics, etc.
Ti~~~ system w:.11 also allow the multicast backbone network to
30 activate a t~~levisior.. set or a VCR. With this feature, a
subscriber i:: able to have the television turn on at a
predetermines: time as well as set the VCR to record a
program at th.e same time or another pre-selected time.
lG
CA 02446852 2003-11-13
With the broadcast system of the present. invention a viewer
or subsc.~-iber will have the ability to persona~.ize or
customi:::~' channel selection, for example, create a list of
favorite programs. Through this feature ~~ viewc.~r can scan
the interactive broadcast schedule, select favorite programs
for a viewing interva:L and have the television automatically
switch to those channels at the appropriate tinv,es.
Virtual recording allows the viewer to "record"/store ~:
program for viewing at a later time. In addition to this
recording feature the system also gives a vie~~~er a one touc':
search feature. Though this feature a viewer c:_~n configure
the system with certain searching criteria suci~ as program
theme, by actor, by program/movie title, etc a~~d with the
one step searching feature retrieve the requested
programming information from the IPG.
The viewer is also provided with the ability to view a
program's video trailer from the electronic program guide
when a viewer "clicks on"/selects that program.
The household consumer is given the ability th:.'ough the
interactive nature of the system to choose fr.o~n differenl~
payment options for the programs selected for viewing, such
as a channel subscription or pay-per-view (PPVj. This means
that a user can purchase a pay-per-view event in real tune
in a self-serve mannez-. A PPV event is determined using data
sent and stored on the: client device. Typically, before a
user can view the PPV programming, he/she baill be required
to confirm the purcha:~e of the event. This will normally
involve the set up of a purchase password that reauires the
CA 02446852 2003-11-13
user to enter the correct password to purchase the PPV event
and view the event at its scheduled time.
The nrovidcr is also able to provide concurrent transmission
of each channel via MPEG-2 and P~IPEG-1 to allow fall bacJc
when access bandwidth becomes impaired or client does not
support MP)JG-2.. This, in effect, is a backup system if
failure occurs on the main transmission facilitv. The
ability to r~scognize the failure of a delivered video signal
t0 and switch to an alternate signal is based on a configurable
algo7-ithm. This increases the level of broadcast
availability in the event of a loop (e. g. xDSL) impairment,
encoder fai 1 ure, or facility/network failure. This a 1 so
allo~~:s for multiple. scat-tops in a single home to negotiate
fo~w best available video. This is shown in Figure 1C.
Th-a system or the invention permits transcoding of satellite
transmission directly to IP multicast MPEG. This takes
existing digital transmissions from a satellite and
20 reprocesses them for delivery on an TP Multicast delivery
system. The advantages of this are that it lowers the cost
of head-end equipment (satellite dish, etc.) by replacing
the encoder ~:Jith a transcoder, and it also maximizes the
quality of the signal being delivered from a digital signal
source at thn head-end.. It is only digitized once, and
remains that way. At the broadcast provider location a
split/distributed head-end (signal from satellite) car_ also
be employed to optimize transport facility cost.
.0 One of the significant features of the present invention is
that a viewer is able to see their household's viewing
history logs; household repeats (programs that are viewed
regularly, or programs that have been seen before, for
18
CA 02446852 2003-11-13
example). This, obviously, provides a parent the means to
determine the amount of television being viewed by children
and whether the programs watched are suitable.
The system also provided for sti 11-picture channel brow~ir~y
by the viewer wizen avail able. This means that a viewer ~~.~il~
be able to see a still "view's of a program listed in the
electronic program guide.
1o Other features provided by the invention include Multicast
download where information required to. boot a network dE:vice
to a multicast group is constantly delivered b~ a network
server. The DHCP server is configured to rcturtw: the
multicast address and port as parameters in a L~OOTP
response. The network device is programmed to join the
multicast group and download a bootstrap progr~im to local
memory and boot from 'she local memory rather tinan across tl:e
network. Also, the system can provide a multicast filesystem
wherein a server constantly delivers a read-only filesysterl
2o to a multicast group. A network device is prog~.-ammed to
access the filesystem by joining the multicast group and
waiting until the requested file appears. Encryption is used
for security and compression is used to minimize bandwidth.
Since multicast UDP may lose packets, the multicast group is
rejoined and holes in the files are filled if holes exist.
Industrial Appl~.cabili~
In summary, thisinvention is applicable to technologies
30 such as xDSL, MPEG-2, MPEG-1, Internet Protocc:' (IP),
including IP multicast and unicast existing copper plant, or
any other broadband IP-enabled network including LMDS and
EFC. The system will work with a personal computer or with a
19
CA 02446852 2003-11-13
television set in conjunction with a set-top box and a
remote control/keyboard. The system allows broadcast
provida~z-s to delive,- broadcast television and Internee
access to subscribers over, for example, existing copper
access lines, utilizing the Internet protocol.
While pay°ticular emu>odiments of the imVention have been
descr,~.bed and illustrated it will be apparent to one skilled
in the art that numerous alternatives and variation can be
to implemented. It is to be understood, however, that such
alternatives and variations will fall within the scope of
the invention as defined by the appended claims.
