A method of transmitting a data packet of a multimedia service is provided. The method includes generating a media characteristic corresponding to a single media content component or aggregated media characteristics corresponding to a plurality of multimedia content components, obtaining information used for generating the data packet from the generated media characteristics or aggregated media characteristics, and generating the data packet based on the obtained information used for generating the data packet and transmitting the generated data packet.
|
1. A method of transmitting a data packet of a multimedia service, the method comprising:
generating an aggregated media characteristic by combining media characteristics of a plurality of media content components;
transmitting the data packet including information which indicates whether the data packet includes the aggregated media characteristic; and
generating an encapsulator header including the aggregated media characteristic,
wherein the information is obtained by parsing the aggregated media characteristic from the generated encapsulator header, and
wherein the data packet further includes the plurality of media content components and the aggregated media characteristic.
12. An apparatus for transmitting a data packet of a multimedia service, the apparatus comprising:
an encapsulation layer for generating an aggregated media characteristic by combining media characteristics of a plurality of media content components and generating an encapsulator header including the aggregated media characteristic; and
a delivery layer for transmitting the data packet including information which indicates whether the data packet includes the aggregated media characteristic,
wherein the information is obtained by parsing the aggregated media characteristic from the generated encapsulator header, and
wherein the data packet further includes the plurality of media content components and the aggregated media characteristic.
2. The method as claimed in
3. The method as claimed in
4. The method as claimed in
5. The method as claimed in
6. The method as claimed in
7. The method as claimed in
8. The method as claimed in
9. The method as claimed in
generating a media characteristic of a single media content component;
transmitting a data packet including the media characteristic and the single media content component.
10. The method as claimed in
generating an encapsulator header including the media characteristic,
wherein the information is obtained by parsing the media characteristic from the generated encapsulator header.
11. The method as claimed in
13. The apparatus as claimed in
14. The apparatus as claimed in
15. The apparatus as claimed in
16. The apparatus as claimed in
17. The apparatus as claimed in
18. The apparatus as claimed in
19. The apparatus as claimed in
20. The apparatus as claimed in
21. The apparatus as claimed in
22. The apparatus as claimed in
|
|||||||||||||||||||||||||||||
This application claims the benefit under 35 U.S.C. §119(a) of a Korean patent application filed in the Korean Industrial Property Office on Jun. 14, 2011 and assigned Serial No. 10-2011-0057699, the entire disclosure of which is hereby incorporated by reference.
The presently claimed invention was made by or on behalf of the below listed parties to a joint research agreement. The joint research agreement was in effect on or before the date the claimed invention was made and the claimed invention was made as a result of activities undertaken within the scope of the joint research agreement. The parties to the joint research agreement are 1) Samsung Electronics Co., Ltd., and 2) University-Industry Cooperation Group of Kyung Hee University.
1. Field of the Invention
The present invention relates to a method and an apparatus for transmitting a data packet of a multimedia service. More particularly, the present invention relates to a method and an apparatus for guaranteeing transmission of a data packet and a service quality by using media characteristics for a multimedia service including one or more media content components.
2. Description of the Related Art
A multimedia service refers to a conversational service such as a video telephony service, a streaming service such as a Video On Demand (VOD) service, and a multicast and a broadcast service. A real time multimedia service may be a conversational service, an interactive service, and a streaming service according to a service type. The real time multimedia service may be divided into a unicast service, the multicast service, and the broadcast service according to a number of participants in a service.
IEEE 802.16 Worldwide Interoperability for Microwave Access (WiMAX), IEEE 802.11e Wireless Fidelity Transmission Opportunity (WiFi TXOP), 3GPP Universal Mobile Telecommunications System (UMTS), and 3GPP Long Term Evolution (LTE) each have functions for reserving resources for the multimedia service and guaranteeing the reserved resources.
In traffic specification (tspec), request specification (rspec), and flow specification (flowspec) of the Resource Reservation Protocol (RSVP) of the Internet Engineering Task Force (IETF), parameters used for the resource reservation protocol are defined. The parameters are compatible with IEEE 802.16, IEEE 802.11e, 3GPP UMTS UMTS, and 3GPP LTE communication system. Resources are reserved through a double leaky bucket parameter in IEEE 802.16, IEEE 802.11e, 3GPP UMTS UMTS, and 3GPP LTE communication system.
Referring to
The Rg 101, which is a guaranteed bitrate, refers to a given average bitrate. Even when a bitrate of data temporarily exceeds the guaranteed bitrate Rg 101, it is possible to prevent occurrence of overflow by storing the data in a buffer. A required buffer size is prearranged as B 103. According to circumstances, the buffer size B 103 corresponding to the guaranteed bitrate may be indicated as Bg, which is a guaranteed buffer size. A peak bitrate Rp 105 may also be prearranged. Based on an assumption that the peak bitrate Rp 105 is retained within a cycle on which one packet is transferred, a buffer size Bp 107 for the peak bitrate may be determined as a maximum size of a Service Data Unit (SDU). In general, a value of the maximum size of the SDU may be indicated in a Maximum Transfer Unit (MTU).
Table 1 below shows examples of various protocols using the four parameters of the double leaky bucket.
TABLE 1
IETF RSVP,
IEEE802.16
3GPP UMTS
IEEE802.11e‘tspec’
(WIMAX)
& LTE
MPEG-4 OD
ATM
Rp
p
Min. reserved
Maximum
avgBitrate
PCR
traffic rate
bitrate (4B)
Bp
M
SDU size
Maximum
MAX_AU_SIZE
CDVT
SDU size
Rg
r
Max. sustained
Guaranteed
AverageBitRate
SCR
traffic rate
bitrate (4B)
Bg
b
Maximum
k*Maximum
bufferSizeDB
BT
Latency
SDU
Accordingly, for compatibility with a resource reservation protocol of a lower layer, the media characteristics should be configured in a form of parameters of the double leaky bucket in a multimedia content such as an MPEG (Moving Picture Experts Group) content.
Aspects of the present invention are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below.
In accordance with an aspect of the present invention, a method of transmitting a data packet of a multimedia service is provided. The method includes generating a media characteristic corresponding to a single media content component or aggregated media characteristics corresponding to a plurality of multimedia content components, obtaining information used for generating the data packet from the generated media characteristics or aggregated media characteristics, and generating the data packet based on the obtained information used for generating the data packet and transmitting the generated data packet.
In accordance with another aspect of the present invention, an apparatus for transmitting a data packet of a multimedia service is provided. The apparatus includes an encapsulation layer for generating a media characteristic corresponding to a single media content component or aggregated media characteristics corresponding to a plurality of multimedia content components, a control layer for obtaining information used for generating the data packet from the generated media characteristics or aggregated media characteristics, and a delivery layer for generating the data packet based on the obtained information used for generating the data packet and transmitting the generated data packet.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding, but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purposes only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
A recent multimedia service takes a form of a mashup multimedia service. The mashup multimedia service may include a combination of various media content components such as a text, a UI (User Interface), and an application program as well as a typical combination in which an audio component and a video component are combined.
Since the combination of media content components varies depending on a state of a transport network, capability of a user terminal, and user preference, media characteristics for each combination are needed.
When a data packet of a multimedia service consisting of or including such various media content components is transmitted, information generated by combining media characteristics in each media content component is needed in order to use a resource reservation protocol supported by each network and a protocol for guaranteeing a service quality.
The “media characteristics” generated by combining media characteristics in various multimedia content components are defined herein as “aggregated media characteristics”. A method of generating and using the aggregated media characteristics is described below.
The aggregated media characteristics may be a type of guideline providing a method of combining respective content components to a service provider and a user and also a multimedia service including a plurality of content components may be expressed by one aggregated media characteristic, which makes the multimedia service easily operated.
For example, when a streaming service for a stored media is performed, an easy access may be achieved by placing the aggregated media characteristics at the beginning of a content file of the stored media. In a case of a stored content encoded in advance, a value of the aggregated media characteristics may be determined based on information measured in an encoding process or generated through traffic shaping of each media data in a process of generating the aggregated media characteristics.
In a case of services encoding and transmitting a media content component in real time such as a live service (e.g. sports broadcasting) or a conversational service (e.g. a video conference), the aggregated media characteristics may be generated by collecting respective media characteristics from an encoder of each media content component and combining the collected media characteristics. Alternatively, the aggregated media characteristics may be generated through traffic shaping (that is, through a control according to a traffic characteristic) according to previously defined aggregated media characteristics.
The generated aggregated media characteristics may be used in a process of establishing a session of the multimedia service. An exemplary embodiment of using the generated aggregated media characteristics is described below.
Referring to
Referring to
When audio and video content components have various qualities, a combination of the content components may be diversely configured according to three factors (a network state, device capability, and user preference). For example, when a connected user having stable and sufficient available bitrates requires a high definition content, a service according to the AD1 combinations 201 and 207 shown in
Accordingly, the aggregated media characteristics are needed to apply the resource reservation protocol of the lower layer and the protocol for guaranteeing the service quality to each of the combined content components in a situation where various qualities of service combinations are possible for one multimedia service.
When there is a media content component (e.g. a scalable video or a simulcast video) in which various qualities of services may be provided, aggregated media characteristics for each combination of the content components may be generated through the following method.
Hereinafter, it is assumed that there are inherent media characteristics for each media content component and each media characteristic is expressed by a double leaky bucket parameter. In a description related to the following equations, Rg1 , Rg2, B1, B2, Rp1, Rp2, Bp1, Bp2, PLR (Packet Loss Ratio)1, PLR2, P1, P2, D1, and D2 refer to “media characteristics”, respectively, and Rg, B, Rp, Bp, PLR, P, and D refer to “aggregated media characteristics”.
Guaranteed (or sustainable) bitrate Rg=Rg1+Rg2
the guaranteed bitrate may be expressed by adding two guaranteed bitrates.
Buffer size B=(B1+B2)*a (a≦1)
in the buffer size, it is safe to add two buffer sizes (wherein a=1). However, when different interleaving methods are applied to respective media streams or time points when the respective media streams are stored in a buffer are different due to a different state of a transmission channel, moments when the buffers are actually full are not the same, so that the required buffer size B may be less than the sum of the two buffer sizes by a ratio of a (wherein a<1).
Peak bitrate Rp=(Rp1+Rp2)*b (b≦1) or Rp=Rg+max(Rp1−Rg1, Rp2−Rg2)
(1) in the peak bitrate, it is safe to add two peak bitrates (wherein b=1). However, when different interleaving methods are applied to respective media streams or time points when the respective media streams are stored in a buffer are different due to a different state of a transmission channel, moments when the two bitrates become peak are different. Accordingly, the actual peak bitrate may be less than the sum of the two peak bitrates by a ratio of b (b<1).
(2) a second equation (Rp=Rg+max(Rp1−Rg1, Rp2−Rg2)) corresponds to a method of obtaining Rp based on an assumption that, when one bitrate becomes peak, the other bitrate has the guaranteed bitrate. In a video packet, for example, since the peak bitrate is determined by a size of an I frame (Intra-frame) and a size of a P/B frame is close to the guaranteed bitrate, a result in accordance with an actual environment may be obtained through the second equation.
Peak buffer (or MTU) size Bp=(Bp1+Bp2)*g (g≦1) or Bp=max(Bp1, Bp2)
if two peaks appear simultaneously, Bp=Bp1+Bp2 (wherein g=1). Further, when different interleaving methods are applied to respective media streams or time points when the respective media streams are stored in a buffer are different due to a different state of a transmission channel, two peaks do not appear at the same time, so that the first equation with g<1 may be used. Alternatively, the aggregated peak buffer (or MTU) size may be expressed by the second equation (Bp=max(Bp1, Bp2)).
Referring to
In
Maximum PLR=min(PLR1, PLR2)
in order to guarantee a desired quality, a minimum value of an acceptable maximum PLR (maximum packet loss ratio) is selected. When there are one or more maximum PLR parameters, the minimum value of the maximum PLR parameters becomes a maximum PLR of the aggregated stream (content).
Priority P=max(P1, P2)
in order to guarantee a desired quality, an acceptable relative priority follows a high priority. When there are one or more priority parameters, a maximum value of priorities becomes the priority of the aggregated stream (content).
Maximum delay D=min(D1, D2)
the maximum delay is applied to a whole session as one value. There may be three services, such as an optional (conversational) service, a streaming service, and a download service. The conversational service allows an end-to-end delay up to 150 ms. The streaming service allows a delay of 1 to 10 seconds. The download service has no condition for a delay. A live streaming follows a streaming standard. When a maximum delay is large, a peak buffer size is increased and thus a peak bitrate is decreased so that the maximum delay may be reduced. When there are one or more maximum delay parameters, a minimum value of the maximum delay parameters becomes the maximum delay of the aggregated stream (content).
A syntax for specifying the media characteristics and the aggregated media characteristics and semantics for each field are described below with reference to Table 2.
Since a name and a size of each field, and a type of parameter indicating each field in Table 2, are selected considering their functions in embodiments of the present invention as described above, they may vary depending on the intention or usual practice of a user or an operator. However, the semantics of each field should follow the definition provided herein.
TABLE 2
size
media_characteristics ( ) {
(bits)
type
composition_flag
1
flag bit
max_packet_lost_ratio / max_lost_packet_number
32
float/
unsigned
integer
stream_priority / stream_precedence
6
unsigned
integer
token_bucket_rate
32
float
token_bucket_size
32
float
peak_data_rate
32
float
max_packet_size
32
unsigned
integer
if ( composition_flag == 1 ) {
num_of_streams
8
unsigned
integer
for ( Idx = 0; Idx < num_of_streams; Idx++) {
stream_id[Idx]
8
unsigned
integer
}
} else {
stream_id
8
unsigned
integer
}
}
Although it is described as an example that the composition flag indicates whether the media characteristics are the aggregated media characteristics, the composition flag may indicate other information on whether a resolution is supported. Further, information indicated by the composition flag is defined in Configuration Information (CI).
A method of generating and using the media characteristics according to an exemplary embodiment of the present invention is described below. The media characteristics may be generated in a generation (capture or grab) process of the content or an encapsulation process of media data encoded in advance.
An exemplary embodiment of the present invention introduced in the following description will be discussed based on the MMT. An encapsulation layer, a delivery layer, and a control layer divided according to their functions internally in the MMT are described, respectively.
Referring to
The MMT asset header 500 includes an MMT asset description field 501. The media characteristic for a single MMT asset may be described in the MMT asset description field 501. Accordingly, when the MMT item includes the single MMT asset, it is possible to use the media characteristics included in the MMT asset description field 501 of the MMT asset header 500.
Since the MMT item may include one or more MMT assets, the MMT item header 510 includes MMT asset list information 511. Information (e.g. temporal or spatial presentation information) on the relation between respective MMT assets included in the MMT item is provided as MMT item composition information 513. The aggregated media characteristics may be located in the MMT item composition information 513.
The MMT control layer exchanges service discovery information, Quality of Experience (QoE) management information, and Digital Rights Management (DRM) information between an MMT server and an MMT client. In a process of exchanging the service discovery information, the MMT control layer may perform a network resource reservation for establishing a session. Accordingly, the MMT control layer obtains the (aggregated) media characteristics to be served by parsing information of the MMT item composition field 513 of the MMT item header 510 or information of the MMT asset description field 501 of the MMT asset header 500, and performs the resource reservation using the obtained media characteristics.
The MMT delivery layer transmits an encapsulated media data packet from a server to a client and exchanges information between layers (e.g. an interface between layers) within a terminal Accordingly, the delivery layer generates a delivery packet. The delivery packet parses information, which should be included for each delivery packet, from the (aggregated) media characteristics included in the MMT item composition field 513 of the MMT item header 510 or the MMT asset description field 501 of the MMT asset header 500, and then uses the parsed information.
The information, which should be included in each delivery packet, includes a priority distinguisher and a delivery delay distinguisher. When the resource reservation is implemented through the control layer, a distinguisher for a reserved flow is needed. When the delivery layer reserves resources for the MAC/PHY layer according to a cross-layer design, (aggregated) media characteristics for the MMT item (or MMT asset) are needed.
Referring to
The generated media characteristics are included in information (e.g., the double leaky bucket parameter) used in the process of establishing a session of a media service and each delivery packet so that they may be distinguished into information (e.g., stream_priority/stream_precedence) indicating a relative priority for each packet.
In a case of the information used in the session establishment process, the media characteristics are transmitted (606) to a control layer (C layer) 605. The control layer 605 parses a value of a field corresponding to the information used in the session establishment process and transfers the parsed value to a control layer 609 of a client 602 through a signaling via a control channel or a protocol (e.g., a Real-Time Stream Protocol (RTSP) or a Session Initiation Protocol (SIP)).
In a case of information (e.g. stream_priority/stream_precedence of Table 2) which may be used in every delivery packet, the generated media characteristics are transferred (606) to the control layer 605. The control layer 605 parses a value of a field corresponding to information which may be used in every delivery packet and transfers (607) the parsed value to the delivery layer (D layer) 604. Alternatively, the delivery layer 604 directly receives (608) the encapsulator header 520 of the media characteristics generated by the encapsulation layer 603 and directly parses a value of a field corresponding to information which may be used in every delivery packet so that the information may be obtained. After inserting the information in every delivery packet (e.g., stream_priority/stream_precedence of Table 2, which may be used in every delivery packet), the delivery layer 604 may transmit the delivery packet to the client 602 (particularly, the delivery layer 610 of the client) and/or entities of an intermediate network via the data channel.
Referring to
The MMT server extracts information used for the session establishment process and information which may be used in every delivery packet by parsing the generated media characteristics in step 703. The information used for the session establishment may be transferred to the MMT client by using signaling via the control channel or the protocol. Operations of parsing and extracting the information may be performed by the control layer of the MMT server.
The MMT server generates the delivery packet and transmits the generated delivery packet to the MMT client in step 705. Operations of generating and transmitting the delivery packet are performed by the delivery layer of the MMT server. In generating the delivery packet, information such as stream_priority or stream_precedence parsed from the media characteristics generated in advance is used. The delivery layer may receive the information parsed by the control layer of the MMT server or obtain the information by parsing the media characteristics.
When the resource reservation for transmitting the media content is completed through the above procedures and a service is started, each delivery packet may use a packet identifier.
The packet identifier identifies whether a packet is included in a corresponding aggregated flow when resources are reserved and the packet is transmitted. A PID is used to distinguish packets including packets of a flow in which resources are reserved and packets which are not reserved, the packets being mixed in a network. The PID may be divided into an explicit part and an implicit part.
The explicit ID contains a totally arranged parameter regardless of a service or a session. The explicit ID is used for Quality of Service (QoS) per class such as DSCP of IETF diffServ. The explicit ID is used to differentiate a relative QoS. Here, a loss priority and a delay priority are used. The delay priority may be expressed by two bits (e.g., a conversational service, an interactive service, a streaming service, and a download service may be expressed by 11, 10, 01, and 00, respectively) since the delay priority uses three or four distinctions. The loss priority is classified into three steps (3GPP UMTS) or eight steps (diffServ) in the standard. Accordingly, the loss priority may be expressed by three bits and indicates high sensitivity to packet loss as a priority value is high.
The implicit ID is used for a guaranteed service. The implicit ID is used to utilize resources reserved in a corresponding flow. One label is assigned for each reserved flow. Semantics of the label have not been defined. A router, a base station, an AP (Access Point), etc. guarantee to use reserved resources for a corresponding label. Accordingly, when one packet is received, a label is identified, resources reserved for the label are identified, and then a service according to the reserved resources should be provided.
Since the router has only to distinguish flows (source IP address, destination IP address) through a temporary serial number when the flows are already determined for the label so that the flows do not overlap, only seven bits are sufficient. The implicit ID is assigned eight bits, wherein a first bit indicates whether such as label is used. The label may be similar to a label in label switching. Although label swapping is performed, a label recognized by an application layer of a terminal should be set in both end nodes.
The operation or the flowchart of the signal shown in
The aforementioned operations may be implemented by installing a memory device storing a corresponding program code in a component within a service device or a client device. An encapsulation layer (E layer), a control layer (C layer), and a delivery layer (D layer) which are respective layers of the server device or the client device read and execute the program code stored in the memory device through a processor or a CPU (Central Processing Unit) so that the aforementioned operations may be implemented.
Accordingly, exemplary embodiments of the present invention have the following representative effects. Exemplary embodiments of the present invention may provide an adaptive multimedia service according to a network state, capability of a terminal, and characteristics of a user by utilizing aggregated media characteristics during a process of transmitting multimedia data including a plurality of media content components.
Exemplary embodiments of the present invention may also generate media characteristics by using the double bucket parameter, so that transmission data of the combined multimedia content components may be easily compatible with the resource reservation protocol provided by the lower network, and the resources and the QoS protocol for guaranteeing a service quality may be easily used.
While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.
Song, Jae-Yeon, Lee, Yong-hun, Park, Kyung-Mo, Hwang, Sung-Oh, Suh, Doug-Young, Kim, Jun-Oh
| Patent | Priority | Assignee | Title |
| Patent | Priority | Assignee | Title |
| 5107780, | Sep 26 1990 | G. M. Pfaff Aktiengesellschaft | Pattern match sewing machine |
| 6031963, | Feb 03 1995 | Kabushiki Kaisha Toshiba | Image information encoding/decoding system |
| 6639746, | Sep 16 1999 | SAMSUNG ELECTRONICS CO , LTD | Method and apparatus for recording/reproducing multi-channel data |
| 7336624, | Apr 12 1999 | Intel Corporation | Broadcast discovery in a network having one or more 1394 buses |
| 7646828, | Aug 24 2007 | LG Electronics Inc | Digital broadcasting system and method of processing data in digital broadcasting system |
| 8432846, | Nov 08 2005 | LENOVO BEIJING LIMITED | Point-to multipoint wireless display method |
| 20010007568, | |||
| 20010022785, | |||
| 20020021321, | |||
| 20060168133, | |||
| 20070081586, | |||
| 20070086481, | |||
| 20090138415, | |||
| 20100260254, | |||
| 20110045802, | |||
| 20110064020, | |||
| 20110119395, | |||
| 20120209907, | |||
| 20120250690, | |||
| 20120317272, | |||
| KR1020010102435, | |||
| KR1020080045276, | |||
| KR1020080066718, | |||
| KR1020090010913, | |||
| WO2011068355, |
| Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
| Jun 13 2012 | Samsung Electronics Co., Ltd. | (assignment on the face of the patent) | / | |||
| Jun 13 2012 | UNIVERSITY-INDUSTRY COOPERATION GROUP OF KYUNG HEE UNIVERSITY | (assignment on the face of the patent) | / |
| Date | Maintenance Fee Events |
| Date | Maintenance Schedule |
| Nov 25 2017 | 4 years fee payment window open |
| May 25 2018 | 6 months grace period start (w surcharge) |
| Nov 25 2018 | patent expiry (for year 4) |
| Nov 25 2020 | 2 years to revive unintentionally abandoned end. (for year 4) |
| Nov 25 2021 | 8 years fee payment window open |
| May 25 2022 | 6 months grace period start (w surcharge) |
| Nov 25 2022 | patent expiry (for year 8) |
| Nov 25 2024 | 2 years to revive unintentionally abandoned end. (for year 8) |
| Nov 25 2025 | 12 years fee payment window open |
| May 25 2026 | 6 months grace period start (w surcharge) |
| Nov 25 2026 | patent expiry (for year 12) |
| Nov 25 2028 | 2 years to revive unintentionally abandoned end. (for year 12) |