FIELD OF INVENTION
[0001] The present subject matter relates to transmission of multicast videos
in passive optical networks and, particularly but not exclusively, to transmission of
multicast Internet Protocol videos packets in gigabit-capable passive optical
networks. 5
BACKGROUND
[0002] Passive optical networks, such as gigabit-capable passive optical
networks (GPONs), are employed for transmission of multicast videos from service
providers to multiple users. Multicasting is understood as provisioning of videos by
one or more service providers to multiple users that are registered with the service 10
provider(s). Such users may be commonly referred to as subscribers. The videos may
be provided to the GPONs in the form of Internet Protocol (IP) based video packets
through one or more communication channels over the Internet. Such videos are
referred to as IP videos or IP video packets.
SUMMARY  15
[0003] This summary is provided to introduce concepts related to
transmission of multicast Internet Protocol (mIP) videos over gigabit-capable passive
optical networks (GPONs). This summary is not intended to identify essential
features of the claimed subject matter nor is it intended for use in determining or
limiting the scope of the claimed subject matter. 20
[0004] In accordance with an embodiment of the present subject matter, an
optical line terminal (OLT) for transmission of videos in a gigabit-capable passive
optical network is described. The OLT includes multiple GPON encapsulation
method (GEM) ports, a forwarder to receive multicast Internet Protocol (mIP) video
packets of a plurality of service providers and forward the mIP video packets to the 25
multiple GEM ports, and a GPON media access control (MAC) unit to encapsulate
the mIP video packets into GEM frames. The OLT includes a control unit to
 
3

configure the forwarder to allocate a separate GEM port, from amongst the multiple
GEM ports, to the mIP video packets of each of the plurality of service providers, and
configure the GPON MAC unit to code a GEM port identifier in each of the GEM
frames before transmitting the GEM frames to at least one optical network terminal
through an optical fiber link. The GEM port identifier is unique for each of the GEM 5
ports associated with the mIP video packets of each of the plurality of service
providers.
[0005] In accordance with an embodiment of the present subject matter, an
optical network terminal (ONT) for transmission of videos in a gigabit-capable
passive optical network is described. The optical network unit includes multiple 10
GPON encapsulation method (GEM) ports to receive GEM frames comprising
multicast Internet Protocol (mIP) video packets of a plurality of service providers and
comprising GEM port identifiers unique for each of the plurality of service providers,
and includes a GPON media access control (MAC) unit to decapsulate the GEM
frames to extract the mIP video packets. The ONT includes a control unit to allocate a 15
separate GEM port, from amongst the multiple GEM ports, to the GEM frames
associated with each of the GEM port identifiers, and configure the GPON MAC unit
to remove the GEM port identifier from each of the GEM frames and identify a
service provider associated with the mIP video packet based on the GEM port
identifier in each of the GEM frames. 20
[0006] In accordance with another embodiment of the present subject matter,
a method for transmission of videos in a gigabit-capable passive optical network
includes receiving, with an optical line terminal, multicast Internet protocol (mIP)
video packets of a plurality of service providers, and allocating a separate GPON
encapsulation method (GEM) port, from amongst multiple GEM ports in the optical 25
line terminal, to the mIP video packets of each of the plurality of service providers.
The method also includes encapsulating the mIP video packets into GEM frames, and
coding a GEM port identifier in each of the GEM frames before transmitting the
 
4

GEM frames from the optical line terminal to at least one optical network terminal
through an optical fiber link. The GEM port identifier is unique for each of the GEM
ports associated with the mIP video packets of each of the plurality of service
providers.
[0007] In accordance with another embodiment of the present subject matter, 5
a method for transmission of videos in a gigabit-capable passive optical network
includes receiving, with an optical network terminal, GPON encapsulation method
(GEM) frames comprising multicast Internet Protocol (mIP) video packets of a
plurality of service providers and comprising GEM port identifiers unique for each of
the plurality of service providers, and includes allocating a separate GEM port, from 10
amongst multiple GEM ports in the optical network terminal, to the GEM frames
associated with each of the GEM port identifiers. The method also includes
decapsulating the GEM frames to extract the mIP video packets and remove the GEM
port identifier from each of the GEM frames, and identifying a service provider
associated with the mIP video packet based on the GEM port identifier in each of the 15
GEM frames.
[0008] In accordance with another embodiment of the present subject matter,
a computer readable medium having a set of computer readable instructions is
disclosed. The computer readable instructions on the computer readable medium,
when executed, perform acts including receiving, with an optical line terminal, 20
multicast Internet protocol (mIP) video packets of a plurality of service providers;
allocating a separate GPON encapsulation method (GEM) port, from amongst
multiple GEM ports in the optical line terminal, to the mIP video packets of each of
the plurality of service providers; encapsulating the mIP video packets into GEM
frames; and coding a GEM port identifier in each of the GEM frames before 25
transmitting the GEM frames from the optical line terminal to at least one optical
network terminal through an optical fiber link. The GEM port identifier is unique for
 
5

each of the GEM ports associated with the mIP video packets of each of the plurality
of service providers.
[0009] In accordance with another embodiment of the present subject matter,
a computer readable medium having a set of computer readable instructions is
disclosed. The computer readable instructions on the computer readable medium, 5
when executed, perform acts including receiving, with an optical network terminal,
GPON encapsulation method (GEM) frames comprising multicast Internet Protocol
(mIP) video packets of a plurality of service providers and comprising GEM port
identifiers unique for each of the plurality of service providers; allocating a separate
GEM port, from amongst multiple GEM ports in the optical network terminal, to the 10
GEM frames associated with each of the GEM port identifiers; decapsulating the
GEM frames to extract the mIP video packets and remove the GEM port identifier
from each of the GEM frames; and identifying a service provider associated with the
mIP video packet based on the GEM port identifier in each of the GEM frames.
BRIEF DESCRIPTION OF THE FIGURES 15
[0010] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit(s) of a reference number
identifies the figure in which the reference number first appears. The same numbers
are used throughout the figures to reference like features and components. Some
implementations of systems and/or methods of the present subject matter are now 20
described, by way of example only, and with reference to the accompanying figures.
[0011] Figure 1 illustrates a gigabit-capable passive optical network (GPON)
environment, according to an implementation of the present subject matter.
[0012] Figure 2(a) illustrates an optical line terminal of the GPON
environment, according to an implementation of the present subject matter. 25
[0013] Figure 2(b) illustrates an optical network terminal of the GPON
environment, according to an implementation of the present subject matter.
 
6

[0014] Figure 3 illustrates a method for transmission of multicast videos in a
GPON network, according to an implementation of the present subject matter.
[0015] Figure 4 illustrates a method for transmission of multicast videos in a
GPON network, according to an implementation of the present subject matter.
[0016] It should be appreciated by those skilled in the art that any block 5
diagrams herein represent conceptual views of illustrative systems embodying the
principles of the present subject matter. Similarly, it will be appreciated that any flow
charts, flow diagrams, state transition diagrams, pseudo code, and the like represent
various processes which may be substantially represented in computer readable
medium and so executed by a computing device or processor, whether or not such 10
computing device or processor is explicitly shown.
DESCRIPTION OF EMBODIMENTS
[0017] The present subject matter relates to devices and methods for
transmission of multicast videos in gigabit-capable passive optical networks
(GPONs). 15
[0018] A GPON environment typically has an optical line terminal (OLT)
communicatively coupled to one or more optical network terminals (ONTs) through a
single optical fiber link for transmission of videos over the GPON network. The OLT
is a terminal device at one end of the optical fiber link and is either located in or away
from a central office of the agency associated with the GPON network. The ONT is a 20
terminal device at the other end of the optical fiber link and is located near or in the
premises of subscribers that are served by that ONT. The OLT receives the multicast
video in the form of multicast Internet Protocol (mIP) video packets from multiple
service providers and distributes the mIP video packets over the optical fiber link to
the ONTs. The ONTs receive the mIP video packets from the optical fiber link, and 25
provide the mIP video packets to the subscriber devices, such as televisions, set-top
boxes, computers, and the like, for subscribers to view the videos. Each of the ONTs
 
7

may serve the mIP video packets to one or more subscriber devices directly or via a
residential gateway, depending on the configuration of the network environment.
[0019] For a downstream transmission over a GPON network, the OLT and
the ONTs conventionally use a single multicast GPON encapsulation method (GEM)
port to carry mIP video packets from multiple service providers. The multicast GEM 5
port is a virtual port. The mIP video packets are carried by the multicast GEM port
for transmitting the mIP video packets between the OLT and the ONTs. For this, in
the OLT, the mIP video packets are encapsulated into GEM frames that carry the mIP
video packets over the GPON network. Each GEM frame is coded with a GEM Port
identifier (ID), which is indicative of the identity of the GEM Port that has carried the 10
mIP video packets. Based on the GEM port ID, the flow of GEM frames is defined
across the ONTs. In the ONTs, the GEM port IDs in the GEM frames are identified,
and GEM frames are decapsulated to extract the mIP video packets from the GEM
frames. The ONTs forward the mIP video contents of those GEM frames for which
the GEM port ID is acceptable by the ONTs. 15
[0020] The mIP video packets that are carried across the OLT and the ONTs
are traffic-shaped in the OLT and/or the ONTs. The traffic-shaping of data packets is
understood as controlling the volume of packets transmitted over time in the network
by delaying the transmission of excess packets. For traffic-shaping, the excess
packets are stored in a queue, the packets are shaped for transmission at a predefined 20
rate, and the excess packets are scheduled for later transmission. This traffic-shaping
facilitates in keeping checks on the loss of data packets, on the delay or latency in
data packet transmission, and on the bandwidth utilization. Such checks help in
providing a quality-of-service (QoS) to the subscribers for the videos or the video
channels served by the service providers. 25
[0021] Conventionally, with a single multicast GEM port in the OLT or in the
ONTs, the mIP video packets from multiple service providers are traffic-shaped in an
aggregated manner. That is, conventionally, the traffic-shaping is the aggregated
 
8

traffic-shaping for all the mIP video packets from multiple service providers. In the
aggregated traffic-shaping, all the mIP video packets are shaped for transmission at
the same maximum transmission rate. With the aggregated traffic-shaping, the mIP
video packets from each service provider may use the entire bandwidth or may use
the bandwidth for another service provider. Also, with the aggregated traffic-shaping, 5
the latency may be substantially large when the number of service providers and the
mIP video packets are large. The aggregated traffic-shaping leads to provisioning of
an aggregated or a same QoS to the subscribers for the videos or the video channels
provided by the multiple service providers. With this, service level agreements of the
respective service providers with the subscribers cannot be enforced, and the QoS as 10
per the service level agreement of each of the service providers cannot be provided.
[0022] The present subject matter describes devices and methods for
transmission of multicast videos from a plurality of service providers in a GPON
environment. In accordance with the present subject matter, in a GPON network,
devices, such as an OLT and ONTs coupled to the OLT, are provided with multiple 15
multicast GEM ports for carrying mIP video packets of the plurality of service
providers. For the sake of simplicity of the description, the multicast GEM port may
hereinafter be interchangeably referred to as the GEM port in the specification. In the
OLT of the present subject matter, a separate GEM port is allocated to the mIP video
packets of each of the service providers. With this, one GEM port carries the mIP 20
video packets from one service provider. While performing encapsulation of the mIP
video packets carried by each of the GEM ports in the OLT, a GEM port ID, unique
for the each GEM port, is coded in the GEM frames. The unique GEM port ID is
indicative of the identity of the respective GEM port.
[0023] In the ONTs of the present subject matter, a separate GEM port is 25
allocated to the GEM frames associated with each of the GEM port IDs. The GEM
frames with one GEM port ID has mIP video packets of one of the service providers.
With this, in the ONTs, one GEM port carries the GEM frames having the mIP video
 
9

packets of one service provider. While performing decapsulation of the GEM frames,
the mIP video packets are extracted from the GEM frames, the GEM port IDs are
removed from each the GEM frames, and a service provider associated with the mIP
video packets is identified based on the GEM port ID.
[0024] With the mIP packets of each service provider and the corresponding 5
GEM frames being carried by a separate GEM port in the OLT and in the ONTs of
the present subject matter, traffic-shaping of the mIP video packets can be performed
individually for each of the service providers. For each service provider, the traffic
shaping may be performed based on a QoS as per the service level agreement of the
service provider with the subscribers. This facilitates in enforcing the service level 10
agreements, at individual levels, for all the service providers sharing the same GPON
network for providing their video services. Thus, with the devices and the methods of
the present subject matter, the transmission of mIP video packets from multiple
service providers over a GPON network is substantially efficient in comparison to
that with the conventional devices and methods. 15
[0025] In an implementation, the traffic-shaping of the mIP video packets
individually for each of the service providers is performed in the OLT of the present
subject matter. In an implementation, the traffic-shaping of the mIP video packets
individually for each of the service providers is performed in the ONT of the present
subject matter. In an implementation, the traffic-shaping of the mIP video packets 20
individually for each of the service providers is performed in both, the OLT and the
ONT of the present subject matter.
[0026] For this, in an implementation, the OLT and/or the ONT are provided
with multiple queues and multiple rate-shapers. A queue is a module that segregates
and queues the mIP video packets. A rate-shaper is a module that rate-shapes the mIP 25
video packets by limiting the transmission rate of the mIP video packets. In
accordance with the present subject matter, a separate queue is assigned to the mIP
video packets passing through each GEM port for queuing the mIP video packets of
 
10

each service provider. Further, a separate rate-shaper is assigned to the mIP video
packets passing through each queue for rate-shaping of the mIP video packets. The
rate-shaping by each rate-shaper is done individually based on the service provider
associated with the mIP video packets passing through that rate-shaper.
[0027] Further, in an implementation, the OLT and/or the ONT are provided 5
with a scheduler. A scheduler is module that schedules the transmission of the mIP
video packets over the GPON network. The scheduler in the OLT receives the mIP
video packets from the multiple rate-shapers, and schedules their transmission to the
one or more ONTs through an optical fiber link. The scheduler in the ONT receives
the mIP video packets from the multiple rate-shapers, and schedules their 10
transmission to one or more subscribers through a user network interface.
[0028] Further, as the mIP video packets from each service provider are
carried over by separate GEM ports and not by the same GEM port, the mIP videos
from each service provider can be provided substantially securely to the subscribers
of the respective service provider. The subscribers registered with one of the service 15
providers cannot access or view the videos or the video channels from the other
service provider(s). This facilitates in enhancing the security of transmission of
multicast videos from multiple service providers over the GPON network.
[0029] Further, in an implementation, the mIP video packets from the service
providers are provided with one or more virtual local area network (VLAN) codes. 20
Each VLAN code facilitates in multicasting the IP videos to a group of subscribers
and their subscriber devices. The group of subscriber devices can be identified based
on the VLAN code. For the transmission of mIP video packets to a group of
subscriber devices based on a VLAN code, the VLAN code is translated to
subscriber-based VLANs associated with that group of subscriber devices. Such 25
VLAN translation may take place in the OLT or the ONTs.
[0030] With a single multicast GEM port, conventionally, the OLT or the
ONTs have to inspect each of the mIP video packets to perform VLAN translation for
 
11

each service provider. Such VLAN translation is substantially complex, and the
amount of processing done is substantially large. In accordance with the present
subject matter, with one multicast GEM port per service provider, the OLT or the
ONTs can perform VLAN translation on the mIP video packets, individually, for
each service provider based on the GEM port that carries the mIP video packets or 5
the corresponding GEM frames. Thus, the VLAN translation is substantially simple
and the amount of processing done is substantially less.
[0031] Further, as the mIP video packets from each service provider are
carried over by separate GEM ports, performance of transmission of multicast videos
and the video channels for each of the service providers can be monitored in a 10
substantially simple and efficient manner. The performance monitoring may include,
but is not restricted to, checking for packet loss, packet success, latency in
transmission, and such. The performance can be monitored both, in the OLT and in
the ONTs. Conventionally, with a single GEM port used for carrying the mIP video
packets across the OLT and the ONTs, the performance of transmission is monitored 15
by inspecting the GEM frames or the mIP video packets through the VLAN codes for
each of the service providers. This methodology of performance monitoring is
complex and involves substantial processing. However, with the OLT and the ONTs
of the present subject matter, as a separate GEM port is allocated for each of the
service provider, the performance of transmission of multicast videos and video 20
channels for the each service provider can be efficiently monitored through the GEM
port ID in the GEM frames.
[0032] The described methodologies can be implemented in hardware,
firmware, software, or a combination thereof. For a hardware implementation, the
processing units can be implemented within one or more application specific 25
integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing
devices (DSPDs), programmable logic devices (PLDs), field programmable gate
arrays (FPGAs), processors, controllers, micro-controllers, microprocessors,
 
12

electronic devices, other electronic units designed to perform the functions described
herein, or a combination thereof.
[0033] For a firmware and/or software implementation, the methodologies
can be implemented with modules (e.g., procedures, functions, and so on) that
perform the functions described herein. Any machine readable medium tangibly 5
embodying instructions can be used in implementing the methodologies described
herein. For example, software codes and programs can be stored in a memory and
executed by a processing unit. Memory can be implemented within the processing
unit or may be external to the processing unit. As used herein the term "memory"
refers to any type of long term, short term, volatile, nonvolatile, or other storage 10
devices and is not to be limited to any particular type of memory or number of
memories, or type of media upon which memory is stored.
[0034] In another firmware and/or software implementation, the functions
may be stored as one or more instructions or code on a non transitory computer-
readable medium. Examples include computer-readable media encoded with a data 15
structure and computer-readable media encoded with a computer program. Computer-
readable media may take the form of an article of manufacturer. Computer-readable
media includes physical computer storage media. A storage medium may be any
available medium that can be accessed by a computing device. By way of example,
and not limitation, such computer-readable media can comprise RAM, ROM, 20
EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other
magnetic storage devices, or any other medium that can be used to store desired
program code in the form of instructions or data structures and that can be accessed
by a computing device; disk and disc, as used herein, includes compact disc (CD),
laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc 25
where disks usually reproduce data magnetically, while discs reproduce data optically
with lasers. Combinations of the above should also be included within the scope of
computer-readable media.
 
13

[0035] In addition to storage on computer readable medium, instructions
and/or data may be provided as signals on transmission media included in a
communication apparatus. For example, a communication apparatus may include a
transceiver having signals indicative of instructions and data. The instructions and
data are configured to cause one or more processors to implement the functions 5
outlined in the claims. That is, the communication apparatus includes transmission
media with signals indicative of information to perform disclosed functions. At a first
time, the transmission media included in the communication apparatus may include a
first portion of the information to perform the disclosed functions, while at a second
time the transmission media included in the communication apparatus may include a 10
second portion of the information to perform the disclosed functions.
[0036] It should be noted that the description merely illustrates the principles
of the present subject matter. It will thus be appreciated that those skilled in the art
will be able to devise various arrangements that, although not explicitly described
herein, embody the principles of the present subject matter and are included within its 15
spirit and scope. Furthermore, all examples recited herein are principally intended
expressly to be only for pedagogical purposes to aid the reader in understanding the
principles of the invention and the concepts contributed by the inventor(s) to
furthering the art, and are to be construed as being without limitation to such
specifically recited examples and conditions. Moreover, all statements herein reciting 20
principles, aspects, and implementations of the invention, as well as specific
examples thereof, are intended to encompass equivalents thereof.
[0037] The manner in which the devices and methods for transmission of
multicast videos from a plurality of service providers in a GPON environment shall
be implemented has been explained in details with respect to the Figures 1, 2, 3 and 25
4. While aspects of described devices and methods for transmission of multicast
videos from service providers in a GPON network can be implemented in any
number of different computing devices, transmission environments, and/or
 
14

configurations, the implementations are described in the context of the following
exemplary system(s).
[0038] It will also be appreciated by those skilled in the art that the words
during, while, and when as used herein are not exact terms that mean an action takes
place instantly upon an initiating action but that there may be some small but 5
reasonable delay, such as a propagation delay, between the initial action and the
reaction that is initiated by the initial action.
[0039] Figure 1 illustrates a GPON environment 100, according to an
implementation of the present subject matter. The GPON environment 100 has an
OLT 102 and a plurality of ONTs 104-1, 104-2, … , 104-M communicatively 10
coupled to the OLT 102 through an optical fiber link 106. The plurality of ONTs 104-
1, 104-2, … , 104-M, hereinafter, are collectively referred to as ONTs 104, and
individually referred to as the ONT 104. The OLT 102 and the ONTs 104 are
configured to multicast video services offered by a plurality of service providers 108-
1, 108-2, … 108-N (collectively referred to as service providers 108, and individually 15
referred to as the service provider 108) to multiple subscribers.
[0040] The service providers 108, respectively, provide video packets over
communication channels 110-1, 110-2, … , 110-N (collectively referred to as
communication channels 110 and individually referred to as a communication
channel 110). Video packets from each of the service providers 108 comprise videos 20
to be presented to the subscribers. Further, the video packets from each service
provider 108 may have one or more VLAN codes for multicasting the videos therein
to group(s) of subscribers. The OLT 102 receives the video packets over the
communication channels 110 from the service providers 108, and the video packets
are processed to downstream the multicast videos across the OLT 102, the optical 25
fiber link 106, and the ONTs 104 to the subscribers.
[0041] The OLT 102, which may be located in a central office of the agency
operating the GPON network, is configured to receive the video packets, and process
 
15

and convert the received packets to optical signals for their transmission over the
optical fiber link 106. The ONTs 104 are configured to receive the optical signals
with video packets and other contents from the optical fiber link 106, and process and
convert the received optical signals to packets for their transmission to the
subscribers. In the configuration shown in Figure 1, the ONTs 104 receive the same 5
optical signals from the optical fiber link 106. The optical signals from the optical
fiber link 106 may be split using an optical splitter (not shown in Figure 1) and
distributed to the ONTs 104.
[0042] In an implementation, the ONTs 104, which may be located near the
premises of the subscribers, may provide the video packets directly to multiple 10
subscriber devices 112-1, … , 112-P, 114-1, … , 114-Q (collectively referred to as
subscriber devices 112 and 114) associated with the subscribers. In such cases, the
ONTs 104 are responsible for providing the video packets to appropriate subscriber
devices 112 and 114. In an implementation, one or more of the ONTs 104 may
provide the video packets to multiple subscriber devices 116-1, … , 116-R 15
(collectively referred to as subscriber devices 116) through a residential gateway 118.
In such a case, the residential gateway 118 is responsible for providing the video
packets to appropriate subscriber devices 116. The subscriber devices 112, 114, and
116 may include, but are not restricted to, televisions, set-top-boxes, computers,
laptops, personal digital assistants, and such. 20
[0043] As shown in Figure 1, the OLT 102 includes multiple multicast GEM
ports 120-1, 120-2, … , 120-N for carrying the video packets received from the
service providers 108. The multiple multicast GEM ports 120-1, 120-2, … , 120-N in
the OLT 102, hereinafter, are collectively referred to as GEM ports 120, and
individually referred to as the GEM port 120. A separate GEM port 120 is allocated 25
to receive and carry the video packets from each of the service providers 108.
Similarly, each of the ONTs 104 includes multiple multicast GEM ports 122-1, … ,
122-N, 124-1, … , 124-N, and 126-1, … , 126-N (collectively referred to as GEM
 
16

ports 122, 124 and 126, and individually referred to as the GEM port 122, 124 and
126). A separate GEM port 122, 124 or 126 in each of the ONTs 104 is allocated to
receive and carry GEM frames with the video packets from each of the service
providers 108. Although, in Figure 1, the number of GEM ports 120, 122, 124, and
126 is shown to be equal to that of the number of service providers 108, in an 5
implementation, the number of GEM ports in the OLT 102 and in the ONTs 104 may
be more.
[0044] The OLT 102 and the ONTs 104 in the GPON environment 100 are
configured to operate based on GPON standards and protocols. Further, the video
packets are in the form of IP-based data packets that carry multicast videos. Such 10
video packets are referred to as mIP video packets. In an implementation, the mIP
video packets may be provided to the OLT 102 through a communication network
(not shown in Figure 1). For this, the OLT 102 may be communicatively coupled to
the service providers 108 over a communication network. The communication
network may be a wireless or a wired network, or a combination thereof. The 15
communication network can be a collection of individual networks, interconnected
with each other and functioning as a single large network. The communication
network includes an IP network. Depending on the terminology, the communication
network includes various network entities, such as gateways and routers; however,
such details have been omitted to maintain the brevity of the description. Further, it 20
may be understood that the communication between the service providers 108 and the
OLT 102 may take place based on the communication protocol compatible with the
communication network.
[0045] Figures 2(a) and 2(b) illustrate an OLT 102 and an ONT 104 of the
GPON environment 100, respectively, according to an implementation of the present 25
subject matter. As shown in Figure 2(a), the OLT 102 includes an OLT-based control
unit 202 for performing various functions associated with transmission of mIP videos
packets across the OLT 102. For the sake of simplicity, the OLT-based control unit
 
17

202 may hereinafter be referred to as the control unit 202. The control unit 202
includes a memory and interface(s) coupled to a processor (not shown). The memory
may include any computer-readable medium known in the art including, for example,
volatile memory (e.g., RAM), and/or non-volatile memory (e.g., EPROM, flash
memory, etc.). The interface(s) may include a variety of software and hardware 5
interfaces that allow the control unit 202 to interact with other modules and entities in
the OLT 102.
[0046] The processor may be implemented as one or more microprocessors,
microcomputers, microcontrollers, digital signal processors, central processing units,
state machines, logic circuitries, and/or any devices that manipulate signals based on 10
operational instructions. Among other capabilities, the processor is configured to
fetch and execute computer-readable instructions stored in the memory.
[0047] The functions of the control unit 202 may be provided through the use
of dedicated hardware as well as hardware capable of executing machine-readable
instructions in association with appropriate machine-readable instructions. When 15
provided by the control unit 202, the functions may be provided through a single
dedicated processor, through a single shared processor, or through a plurality of
individual processors, some of which may be shared. Moreover, the control unit 202
should not be construed to refer exclusively to hardware capable of executing
machine-readable instructions, and may implicitly include, without limitation, digital 20
signal processor (DSP) hardware, network processor, application specific integrated
circuit (ASIC), field programmable gate array (FPGA), read only memory (ROM) for
storing software, random access memory (RAM), non-volatile storage. Other
hardware, conventional and/or custom, may also be included.
[0048] As shown in Figure 2(a), the OLT 102 includes an OLT-based 25
forwarder 204, simply referred to as the forwarder 204. The forwarder 204 is module
that receives mIP video packets of the service providers 108 and forwards the mIP
video packets to the GEM ports 120. The mIP video packets from each service
 
18

provider 108 are received over the respective communication channel 110, as shown.
In an example, the mIP video packets of each service provider are received in the
form on ethernet frames, each having an ethernet header. The ethernet header in the
ethernet frames is unique for the each service provider. This enables in identifying the
service provider associated with the ethernet frames received by the forwarder 204. 5
[0049] The control unit 202 of the OLT 102 configures the forwarder 204 to
allocate a separate GEM port 120 to the mIP video packets from each of the service
providers 108. With this, each one of the GEM ports 120 receives and carries mIP
video packets associated with one service provider 108. For the allocation of the
GEM port, the forwarder 204 is enabled to identify the service provider based on the 10
ethernet header in the ethernet frames, allocate a separate GEM port 120 for each
service provider based on the identified service provider, and forwards the mIP video
packets in the ethernet frames to the allocated GEM port 120. The mIP video packets
are forwarded by each of the GEM ports 120 for further processing, for example, for
traffic-shaping in the OLT 102. 15
[0050] As shown in Figure 2(a), the OLT 102 includes multiple OLT-based
queues 206-1, 206-2, … , 206-N, hereinafter, are collectively referred to as queues
206, and individually referred to as the queue 206. Each queue 206 performs a part of
functionality for traffic-shaping by segregating and queuing-up the mIP video packets
for rate-shaping. In an implementation, the control unit 202 configures the forwarder 20
204 to assign a separate queue 206 to each GEM port 120 and to the mIP video
packets passing through the each GEM port 120 for queuing-up the mIP video
packets, individually, for each of the service provider 108.
[0051] Further, the OLT 102 includes multiple OLT-based rate-shapers 208-
1, 208-2, … , 208-N, hereinafter, are collectively referred to as rate-shapers 208, and 25
individually referred to as the rate-shaper 208. Each rate-shaper 208 performs a part
of functionality for traffic-shaping by limiting the rate of transmission of the mIP
video packets. In an implementation, the control unit 202 configures the forwarder to
 
19

assign a separate rate-shaper 208 to each GEM port 120 and the mIP video packets
passing through each queue 206. Each separate rate-shaper 208 receives the mIP
video packets from the queue 206 assigned to the corresponding GEM port 120, and
rate-shapes the mIP video packets at individual levels based on the service provider
108 associated with the mIP video packets passing through that rate-shaper 208. 5
[0052] Further, the OLT 102 includes an OLT-based scheduler 210, simple
referred to as the scheduler 210. The scheduler 210 schedules the transmission of the
mIP video packets from the OLT 102 to the optical fiber link 106. The mIP video
packets are transmitted to the optical fiber link 106 in the form of GEM frames. The
GEM frames carry the mIP video packets as payloads. For this, the OLT 102 includes 10
an OLT-based GPON media access control (MAC) unit 212, simple referred to as
GPON MAC unit 212, which encapsulates the mIP video packets into the GEM
frames. The control unit 202 configures the GPON MAC unit 212 to code a GEM
port ID in headers of each the GEM frames during the encapsulation process before
transmitting the GEM frames to the optical fiber link 106. The GEM port ID coded in 15
each of the GEM frames is unique for each of the GEM ports 120 associated with the
mIP video packets of each service provider 108. In an implementation, the control
unit 202 allows the scheduler 208 to receive the mIP video packets from all the rate-
shapers 208, schedule the transmission of the mIP video packets from the OLT 102,
and provide the mIP video packets to the GPON MAC unit in accordance with the 20
schedule for encapsulation of the mIP video packets, coding of the GEM port IDs in
the GEM frames, and transmission of the GEM frames to the optical fiber link 106
for further transmission to one or more ONTs 104.
[0053] In the OLT 102, the information and data in the form of GEM frames
are converted to optical signals for being sent to the optical fiber link 106. In an 25
implementation, the optical signals carrying the GEM frames may be provided to the
optical fiber link 106 through a single link.
 
20

[0054] Further, the GPON environment 100 includes an optical splitter 214.
The optical splitter 214 receives the optical signals carrying the GEM frames from
the optical fiber link 106. The optical splitter 214 then splits the received optical
signals into various optical signals for distributing to the ONTs 104.
[0055] As shown in Figure 2(b), the ONT 104 includes an ONT-based control 5
unit 216 for performing various functions associated with transmission of mIP videos
packets across the ONT 104. For the sake of simplicity, the ONT-based control unit
216 may hereinafter be referred to as the control unit 216. The control unit 216
includes a memory and interface(s) coupled to a processor (not shown). The memory,
the interface(s) and the processor may be similar to those in the control unit 202 of 10
the OLT 102.
[0056] The functions of the control unit 216 may be provided through the use
of dedicated hardware as well as hardware capable of executing machine-readable
instructions in association with appropriate machine-readable instructions. When
provided by the control unit 216, the functions may be provided through a single 15
dedicated processor, through a single shared processor, or through a plurality of
individual processors, some of which may be shared. Moreover, the control unit 216
should not be construed to refer exclusively to hardware capable of executing
machine-readable instructions, and may implicitly include, without limitation, digital
signal processor (DSP) hardware, network processor, application specific integrated 20
circuit (ASIC), field programmable gate array (FPGA), read only memory (ROM) for
storing software, random access memory (RAM), non-volatile storage. Other
hardware, conventional and/or custom, may also be included.
[0057] As shown in Figure 2(b), the ONT 104 includes a receiver 218 that
receives the optical signals with the GEM frames. The GEM frames comprise the 25
mIP video packets of the service providers 108 and the GEM port IDs uniquely coded
for each of the service providers 108. The GEM frames are then received by the GEM
ports 122 from the receiver 218.
 
21

[0058] In an implementation, the control unit 216 of the ONT 104 allocates a
separate GEM port 122 to the GEM frames associated with each GEM port ID. Thus,
each one of the GEM ports 122 receives the GEM frames having the mIP video
packets of one service provider 108. For this, the control unit 216 identifies the GEM
port IDs associated with the Gem frames received in the ONT 104, and accordingly 5
allocates a separate GEM port 122, based on the GEM port ID.
[0059] Further, the ONT 104 includes an ONT-based GPON MAC unit 220,
simply referred to as the GPON MAC unit 220, which receives the GEM frames from
the GEM ports 122 and decapsulates the GEM frames to extract the mIP video
packets therein. The control unit 216 configures the GPON MAC unit 220 to remove 10
the GEM port ID from each of the GEM frames during the decapsulation process, and
identify a service provider associated with the mIP video packets based on the GEM
port ID in each GEM frame. The extracted mIP video packets are then forwarded by
the GPON MAC unit 220 for further processing, for example, for traffic-shaping in
the ONT 104. 15
[0060] As shown in Figure 2(b), the ONT 104 includes an ONT-based
forwarder 222, simply referred to as the forwarder 222. The forwarder 222 is module
that receives mIP video packets of the service providers 108 and forwards the mIP
video packets for further processing.
[0061] Further, the ONT 104 includes multiple ONT-based queues 224-1, 20
224-2, … , 224-N, hereinafter, are collectively referred to as queues 224, and
individually referred to as the queue 224. Similar to that in the OLT 102, each queue
224 performs a part of functionality for traffic-shaping by segregating and queuing-
up the mIP video packets for rate-shaping in the ONT 104. In an implementation, the
control unit 216 configures the forwarder 222 to assign a separate queue 224 to the 25
mIP video packets of each of the service providers 108 for queuing-up the mIP video
packets, individually, for each of the service provider 108.
 
22

[0062] Further, the ONT 104 includes multiple ONT-based rate-shapers 226-
1, 226-2, … , 226-N, hereinafter, are collectively referred to as rate-shapers 226, and
individually referred to as the rate-shaper 226. Similar to that in the OLT 102, each
rate-shaper 226 performs a part of functionality for traffic-shaping by limiting the rate
of transmission of the mIP video packets in the ONT 104. In an implementation, the 5
control unit 216 configures the forwarder 222 to assign a separate rate-shaper 226 to
the mIP video packets passing through each queue 224. Each separate rate-shaper 226
receives the mIP video packets from the queue 224 assigned to the corresponding
GEM port 122, and rate-shapes the mIP video packets at individual levels based on
the service provider 108 associated with the mIP video packets passing through that 10
rate-shaper 226.
[0063] Further, the ONT 104 also includes an ONT-based scheduler 228,
simple referred to as the scheduler 228. The scheduler 228 schedules the transmission
of mIP video packets from the ONT 104 over to subscriber devices. In an
implementation, the control unit 216 allows the scheduler 218 to receive the mIP 15
video packets from all the rate-shapers 226, schedule the transmission of mIP video
packets from the ONT 104, and provide the mIP video packets to a user network
interface 230 in the ONT 104 in accordance with the schedule for further
provisioning of the mIP video packets to one or more subscriber devices. The user
network interface 230 is an interface between the ONT 104 and the subscriber 20
devices to provide mIP video packets to the subscriber devices, either direct or via a
residential gateway. In an implementation, the user network interface 230 may reside
outside the ONT 104.
[0064] In the ONT 104, the information and data received in the form of
optical signals are converted to data (GEM frames) in the form of electrical signals 25
for transmission across the ONT 104 to the user network interface 230. In an
implementation, the electrical signals carrying such data packets may be provided to
the user network interface 230 through a single link.
 
23

[0065] With a separate GEM port 120, 122, a separate queue 206, 224, and a
separate rate-shaper 208, 226 allocated and assigned to the mIP video packets from
each of the service providers 108, traffic shaping of the mIP video packets can be
performed at individual levels for each of the service providers 108. Each rate-shaper
208, 226 can perform the traffic shaping to provide QoS distinctly for each of the 5
service providers 108. The QoS may be based on the service level agreements for
each of the service providers 108. Thus, the service level agreements for each service
provider 108 can be enforced.
[0066] In an implementation, the traffic-shaping as per the service level
agreements of the service providers 108 is performed in the OLT 102. In an 10
implementation, the traffic-shaping as per the service level agreements of the service
providers 108 is performed in the ONTs 104. In an implementation, the traffic-
shaping as per the service level agreements of the service providers 108 is performed
in both, the OLT 102 and the ONTs 104.
[0067] Figure 3 and Figure 4 illustrate methods 300 and 400 for transmission 15
of multicast videos in a GPON network, according to an implementation of the
present subject matter. The order in which the methods 300 and 400 are described is
not intended to be construed as a limitation, and any number of the described method
blocks can be combined in any order to implement the methods 300 and 400, or an
alternative method. Additionally, individual blocks may be deleted from the methods 20
300 and 400 without departing from the spirit and scope of the subject matter
described herein. Furthermore, the methods 300 and 400 can be implemented in any
suitable hardware, software, firmware, or combination thereof.
[0068] A person skilled in the art will readily recognize that steps of the
methods 300 and 400 can be performed by programmed computing devices. Herein, 25
some implementations are also intended to cover program storage devices, for
example, digital data storage media, which are machine or computer readable and
encode machine-executable or computer-executable programs of instructions,
 
24

wherein said instructions perform some or all of the steps of the described method.
The program storage devices may be, for example, digital memories, magnetic
storage media such as a magnetic disks and magnetic tapes, hard drives, or optically
readable digital data storage media. The implementations are also intended to cover
both network and devices configured to perform said steps of the exemplary method. 5
[0069] Referring to Figure 3, although the method 300 for transmission of
multicast videos in a GPON network may be implemented in a variety of network
devices working in different GPON-based network environments; in an
implementation described in Figure 3, the method 300 is explained in context of the
aforementioned OLT 102 for the ease of explanation. 10
[0070] In an implementation, at block 302, mIP video packets of a plurality of
service providers 108 are received by the OLT 102. The mIP video packets of each of
the service providers 108 are tagged with one or more VLAN codes for multicasting
videos to multiple subscribers. The mIP video packets are received in ethernet frames
having ethernet headers, each unique for a service provider 108. 15
[0071] At block 304, a separate GEM port 120 is allocated to the mIP video
packets of each of the service providers 108. The separate GEM port 120 is allocated
from multiple OLT-based GEM ports 120 by the forwarder 204 as configured by the
control unit 202 in the OLT 102.
[0072] At block 306, a separate queue 206 is assigned to the mIP video 20
packets passing through each of the GEM ports 120. The separate queue 206 is
assigned from multiple OLT-based queues 206 by the forwarder 204 as configured by
the control unit 202 in the OLT 102. The queue 206 is assigned for queuing the mIP
video packets.
[0073] Further, at block 308, a separate rate-shaper 208 is assigned to the mIP 25
video packets passing through each of the queues 206. The rate-shaper 208 is
assigned from multiple OLT-based rate-shapers 208 by the forwarder 204 as
configured by the control unit 202 in the OLT 102. The rate-shaper 208 is assigned
 
25

for rate-shaping the mIP video packets. The mIP video packets are received by the
rate-shaper 208 from the queue 206 assigned to the corresponding GEM port 120, and
the mIP video packets are rate-shaped individually for the service provider 108
associated with the mIP video packets passing through the rate-shaper 208. In an
implementation, each rate-shaper 208 rate-shapes the mIP video packets based on the 5
QoS as per the service level agreement of the service provider 108 associated with the
mIP video packets passing through that rate-shaper 208.
[0074] At block 310, after rate-shaping, transmission of the mIP video
packets from the OLT 102 over the optical fiber link 106 is scheduled. The
scheduling is done by the OLT-based scheduler 210 in the OLT 102. The mIP video 10
packets are transmitted from the OLT 102 to the optical fiber link 106 in the form of
GEM frames. For this, the mIP video packets are encapsulated into GEM frames at
block 312. The encapsulation is done by the OLT-based GPON MAC unit 212 in the
OLT 102. Further, before transmitting the GEM frames from the OLT 102 to the
optical fiber link 106, a GEM port ID is coded in each GEM frame at block 314. The 15
GEM port ID is coded in headers of each the GEM frames by the OLT-based GPON
MAC unit 212 as configured by the control unit 202. A unique GEM port ID is coded
in the GEM frames for each of the GEM port associated with the mIP video packets
of each service provider 108. The GEM frames are then transmitted to the optical
fiber link 106 for their further transmission to one or more ONTs 104 in accordance 20
with the scheduling.
[0075] In an implementation, the GEM frames are transmitted over the optical
fiber link 106 in the form of optical signals. The optical signals are split before being
sent to the ONTs 104. The splitting is performed by the optical splitter 214.
[0076] Referring to Figure 4, although the method 400 for transmission of 25
multicast videos in a GPON network may be implemented in a variety of network
devices working in different GPON-based network environments; in an
 
26

implementation described in Figure 4, the method 400 is explained in context of the
aforementioned ONT 104 for the ease of explanation.
[0077] In an implementation, at block 402, GEM frames comprising mIP
video packets of a plurality of service providers 108 and comprising GEM port IDs
are received by the ONT 104. The GEM port IDs are unique for each of the service 5
providers 108. At block 404, a separate GEM port 122 is allocated to the GEM
frames associated with each of the GEM port IDs. The separate GEM port 122 is
allocated from multiple ONT-based GEM ports 122 by the control unit 216 in the
ONT 104.
[0078] At block 406, the GEM frames are decapsulated to extract mIP video 10
packets of the service providers 108. During decapsulation, the GEM port IDs in the
GEM frames are removed. At block 408, based on the GEM port ID in each of the
GEM frames, a service provider 108 associated with the extracted mIP video packets
is identified. The decapsulation of the GEM frames and the identification of the
service providers 108 associated with the extracted mIP video packets is done by the 15
ONT-based GPON MAC unit 220. After this, the mIP video packets are provided to
the ONT-based forwarder 222 for further processing of the mIP video packets.
[0079] At block 410, a separate queue 224 is assigned to mIP video packets of
each of the service providers 108. The separate queue 224 is assigned from multiple
ONT-based queues 224 by the forwarder 222 configured by the control unit 216 in 20
the ONT 104. The queue 224 is assigned for queuing the mIP video packets from the
each service provider 108.
[0080] Further, at block 412, a separate rate-shaper 226 is assigned to mIP
video packets passing through each queue 224. The rate-shaper 226 is assigned from
multiple ONT-based rate-shapers 226 by the forwarder 222 configured by the control 25
unit 216 in the ONT 104. The rate-shaper 226 is assigned for rate-shaping the mIP
video packets. The mIP video packets are received by the rate-shaper 226 from the
queue 224 assigned to the corresponding GEM port 122, and the mIP video packets
 
27

are rate-shaped individually for the service provider 108 associated with the mIP
video packets passing through that rate-shaper 226. In an implementation, each rate-
shaper 226 rate-shapes the mIP video packets based on the QoS as per the service
level agreement of the service provider 108.
[0081] At block 414, transmission of the mIP video packets from the ONT 5
104 to one or more subscriber devices is scheduled. The scheduling is done by the
ONT-based scheduler 228 over the user network interface 230 in the ONT 104. For
this, the mIP video packets are forwarded to the user network interface 230 for their
transmission to the subscriber devices in accordance with the scheduling.
[0082] Although implementations for transmission of multicast videos in a 10
GPON network have been described in language specific to structural features and/or
methods, it is to be understood that the appended claims are not necessarily limited to
the specific features or methods described. Rather, the specific features and methods
are disclosed as exemplary implementations for transmission of multicast videos in
GPON network. 15

 
28

I/We claim:
1. An optical line terminal (102) for transmission of videos in a gigabit-capable
passive optical network (GPON), the optical line terminal (102) comprising:
multiple GPON encapsulation method (GEM) ports (120);
a forwarder (204) to receive multicast Internet Protocol (mIP) video packets 5
of a plurality of service providers (108) and forward the mIP video packets to the
multiple GEM ports (120);
a GPON media access control (MAC) unit (212) to encapsulate the mIP video
packets into GEM frames; and
a control unit (202) to: 10
configure the forwarder (204) to allocate a separate GEM port (120),
from amongst the multiple GEM ports (120), to the mIP video packets of
each of the plurality of service providers (108); and
configure the GPON MAC unit (212) to code a GEM port identifier in
each of the GEM frames before transmitting the GEM frames to at least 15
one optical network terminal (104) through an optical fiber link (106),
wherein the GEM port identifier is unique for each of the GEM ports
(120) associated with the mIP video packets of each of the plurality of
service providers (108).
2. The optical line terminal (102) as claimed in claim 1 further comprising multiple 20
queues (206) for queuing of the mIP video packets, wherein the control unit (202)
configures the forwarder (204) to assign a separate queue (206), from amongst the
multiple queues (206), to the mIP video packets passing through each of the GEM
ports (120).
3. The optical line terminal (102) as claimed in claim 2 further comprising multiple 25
rate-shapers (208) for rate-shaping of the mIP video packets, wherein the control unit
(202) configures the forwarder (204) to assign a separate rate-shaper (208), from
 
29

amongst the multiple rate-shapers (208), to the mIP video packets passing through
each of the multiple queues (206).
4. The optical line terminal (102) as claimed in claim 3, wherein the rate-shaping by
each of the multiple rate-shapers (208) is based on a quality-of-service in accordance
with a service level agreement of a service provider (108) associated with the mIP 5
video packets passing through the each rate-shaper (208).
5. The optical line terminal (102) as claimed in claim 3 further comprising a
scheduler (210) to,
receive mIP video packets from the multiple rate-shapers (208);
schedule transmission of the mIP video packets from the optical line terminal 10
(102); and
provide the mIP video packets to the GPON MAC unit (212) in accordance
with the schedule for encapsulation of the mIP video packets into the GEM
frames, coding the GEM port identifiers in the GEM frames, and transmission of
the GEM frames to the at least one optical network terminals (104) through the 15
optical fiber link (106).
6. An optical network terminal (104) for transmission of videos in a gigabit-capable
passive optical network (GPON), wherein the optical network terminal (104)
comprises:
multiple GPON encapsulation method (GEM) ports (122) to receive GEM 20
frames comprising multicast Internet Protocol (mIP) video packets of a plurality
of service providers (108) and comprising GEM port identifiers unique for each
of the plurality of service providers (108);
a GPON media access control (MAC) unit (220) to decapsulate the GEM
frames to extract the mIP video packets; and 25
a control unit (216) to:
 
30

allocate a separate GEM port (122), from amongst the multiple GEM
ports (122), to the GEM frames associated with each of the GEM port
identifiers; and
configure the GPON MAC unit (220) to remove the GEM port
identifier from each of the GEM frames and identify a service provider 5
(108) associated with the mIP video packet based on the GEM port
identifier in each of the GEM frames.
7. The optical network terminal (104) as claimed in claim 6 further comprising:
multiple queues (224) for queuing of the mIP video packets; and
a forwarder (222) to receive the mIP video packets of the plurality of service 10
providers (108) and forward the mIP video packets to the multiple queues (224),
wherein the control unit (216) configures the forwarder (222) to assign a
separate queue (224), from amongst the multiple queues (224), to the mIP
video packets of each of the plurality of service providers (108).
8. The optical network terminal (104) as claimed in claim 7 further comprising 15
multiple rate-shapers (226) for rate-shaping of the mIP video packets, wherein the
control unit (216) configures the forwarder (222) to assign a separate rate-shaper
(226), from amongst the multiple rate-shapers (226), to the mIP video packets passing
through each of the multiple queues (224).
9. The optical network terminal (104) as claimed in claim 8, wherein the rate- 20
shaping by each of the multiple rate-shapers (226) is based on a quality-of-service in
a service level agreement of a service provider (108) associated with the mIP video
packets passing through the each rate-shaper (226).
10. The optical network terminal (104) as claimed in claim 8 further comprising a
scheduler (228) to: 25
receive mIP video packets from the multiple rate-shapers (226);
 
31

schedule transmission of the mIP video packets from the optical network
terminal (104); and
provide the mIP video packets to a user network interface (230) in accordance
with the schedule for provisioning of the mIP video packets to at least one
subscriber device. 5
11. A method for transmission of videos in a gigabit-capable passive optical network
(GPON), the method comprising:
receiving, with an optical line terminal (102), multicast Internet protocol
(mIP) video packets of a plurality of service providers (108);
allocating a separate GPON encapsulation method (GEM) port (120), from 10
amongst multiple GEM ports (120) in the optical line terminal (102), to the mIP
video packets of each of the plurality of service providers (108);
encapsulating the mIP video packets into GEM frames; and
coding a GEM port identifier in each of the GEM frames before transmitting
the GEM frames from the optical line terminal (102) to at least one optical 15
network terminal (104) through an optical fiber link (106), wherein the GEM port
identifier is unique for each of the GEM ports associated with the mIP video
packets of each of the plurality of service providers (108).
12. The method as claimed in claim 11 further comprising assigning a separate queue
(206), from amongst multiple queues (206) in the optical line terminal (102), to the 20
mIP video packets passing through each of the GEM ports (120) for queuing of the
mIP video packets.
13. The method as claimed in claim 12 further comprising assigning a separate rate-
shaper (208), from amongst multiple rate-shapers (208) in the optical line terminal
(102), to the mIP video packets passing through each of the multiple queues (206) for 25
rate-shaping of the mIP video packets, wherein the rate-shaping by each of the
multiple rate-shapers (208) is based on a quality-of-service for a service provider
 
32

(108) associated with the mIP video packets passing through the each rate-shaper
(208).
14. The method as claimed in claim 13, further comprising:
scheduling transmission of the mIP video packets from the optical line
terminal (102); and 5
provide the mIP video packets from the multiple rate-shapers (208) to a
GPON media access control (MAC) unit (210) in accordance with the schedule
for encapsulation of the mIP video packets into the GEM frames, coding the
GEM port identifiers in the GEM frames, and transmission of the GEM frames to
the at least one optical network terminals (104) through the optical fiber link 10
(106).
15. A method for transmission of videos in a gigabit-capable passive optical network
(GPON), the method comprising:
receiving, with an optical network terminal (104), GPON encapsulation
method (GEM) frames comprising multicast Internet Protocol (mIP) video 15
packets of a plurality of service providers (108) and comprising GEM port
identifiers unique for each of the plurality of service providers (108);
allocating a separate GEM port (122), from amongst multiple GEM ports
(122) in the optical network terminal (104), to the GEM frames associated with
each of the GEM port identifiers; 20
decapsulating the GEM frames to extract the mIP video packets and remove
the GEM port identifier from each of the GEM frames; and
identifying a service provider (108) associated with the mIP video packet
based on the GEM port identifier in each of the GEM frames.
16. The method as claimed in claim 15 further comprising assigning a separate queue 25
(224), from amongst multiple queues (224) in the optical network terminal (104), to
the mIP video packets of each of the plurality of service providers (108) for queuing
of the mIP video packets.
 
33

17. The method as claimed in claim 16 further comprising assigning a separate rate-
shaper (226), from amongst multiple rate-shapers (226) in the optical network
terminal (104), to the mIP video packets passing through each of the multiple queues
(224) for rate-shaping of the mIP video packets, and wherein the rate-shaping by each
of multiple rate-shapers (226) is based on a quality-of-service for a service provider 5
(108) associated with the mIP video packets passing through the each rate-shaper
(226).
18. A computer-readable medium having computer-executable instructions that when
executed perform acts comprising:
receiving, with an optical line terminal (102), multicast Internet protocol 10
(mIP) video packets of a plurality of service providers (108);
allocating a separate GPON encapsulation method (GEM) port (120), from
amongst multiple GEM ports (120) in the optical line terminal (102), to the mIP
video packets of each of the plurality of service providers (108);
encapsulating the mIP video packets into GEM frames; and 15
coding a GEM port identifier in each of the GEM frames before transmitting
the GEM frames from the optical line terminal (102) to at least one optical
network terminal (104) through an optical fiber link (106), wherein the GEM port
identifier is unique for each of the GEM ports associated with the mIP video
packets of each of the plurality of service providers (108). 20
19. A computer-readable medium having computer-executable instructions that when
executed perform acts comprising:
receiving, with an optical network terminal (104), GPON encapsulation
method (GEM) frames comprising multicast Internet Protocol (mIP) video
packets of a plurality of service providers (108) and comprising GEM port 25
identifiers unique for each of the plurality of service providers (108);
 
34

allocating a separate GEM port (122), from amongst multiple GEM ports
(122) in the optical network terminal (104), to the GEM frames associated with
each of the GEM port identifiers;
decapsulating the GEM frames to extract the mIP video packets and remove
the GEM port identifier from each of the GEM frames; and 5
identifying a service provider (108) associated with the mIP video packet
based on the GEM port identifier in each of the GEM frames.