Multiplex communications – Communication techniques for information carried in plural... – Combining or distributing information via time channels
Reexamination Certificate
1999-12-15
2004-04-06
Chin, Wellington (Department: 2664)
Multiplex communications
Communication techniques for information carried in plural...
Combining or distributing information via time channels
C370S537000, C348S441000, C375S301000, C375S321000
Reexamination Certificate
active
06717961
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a format converting apparatus and more particularly to a format converting apparatus for exchanging data between a serial bus and a remodulator.
2. Discussion of Related Art
An Institute of Electrical and Electronics Engineers (IEEE) 1394 is one of the standards for a digital interface allowing a mutual connection between equipments. The IEEE 1394 provides a transmission technique or standard between digital equipments as developed by U.S.A. Apple Co. The IEEE 1394 also provides a new interface standard in which multimedia data can be transmitted and received at a high speed of 100 Mbps~1 Gbps by connecting communication instruments, computers and household electric appliances through a single network.
The IEEE 1394 is based on a remarkable bilateral nature and is recognized as a technique capable of leading the age of multimedia. Especially, the IEEE 1394 supports both an asynchronous transmission such as a printer or scanner which does not require a real time operation, and an isochronous transmission such as a motional image or sound which requires a real time operation. The IEEE 1394 also has a characteristic of transmitting data rapidly and with stability by connecting only one cable in series to a personal computer (PC), regardless of a size or number of peripheral equipments. Accordingly, the development of products and parts for computers and household electric appliances have been accelerated.
FIG. 1
is a block diagram of a conventional digital broadcasting receiver utilizing the IEEE 1394. Referring to
FIG. 1
, a wireless signal is input through an antenna and is converted into a transport stream in a tuner and error corrector
101
. After an error correction, the signal is output to a transport inverse multiplexer (MUX)
104
. The transport stream inverse multiplexed into an audio and video (A/V) packetized elementary streams (PES) by the transport inverse MUX
104
. A Moving Picture Experts Group Audio/Video (MPEG A/V) decoder
105
receives and decompresses the A/V PES. A NTSC/PAL encoder
106
converts the decompressed A/V data into an NTSC or PAL format and outputs the data to a TV or a video cassette recorder (VCR). A controller
100
controls the blocks above and performs functions such as a channel conversion according to inputs from a user. Such digital broadcasting receiver can selectively include one of an IEEE 1394 port
102
or a VSB-R port
103
, or can include both.
The IEEE 1394 port
102
is defined by the standard of an IEEE standard 1394-1995 serial bus, and is embodied by implementing IEEE 1394 physical and link layers. As shown in
FIG. 1
, the IEEE 1394 port
102
is connected to the transport inverse MUX
104
and transmits the transport stream externally or outputs the externally received transport stream to the transport inverse MUX
104
. The VSB-R port
103
is based on a data transmission system defined by the standard of an EIA-
762
and EIA-
761
, and is embodied by implementing a VSB-R. The VSB-R port
103
is also connected to the transport inverse MUX
104
to transmit or receive the transport stream.
FIG. 2
shows a block diagram of the IEEE 1394 physical and link layers (PHY and LINK layers) including a host processor
201
as a controller, a link layer
202
, a physical layer
203
and an IEEE 1394 cable. The IEEE 1394 cable is provided as a physical unit used for forming a bus to exterior equipments. The physical layer
203
is connected to the IEEE 1394 bus utilizing the IEEE 1394 cable, loads transmission digital data on the IEEE 1394 bus and extracts data from the IEEE 1394 bus.
The digital data transferred by the bus is classified into either an isochronous data or an asynchronous data depending upon its attribute. The isochronous data is transferred through an isochronous channel by a constant transmission rate to ensure a real time transmission. The asynchronous data is transferred through an asynchronous channel and is particularly transmitted intermittently utilizing a spare bandwidth of the bus. In general the isochronous channel has a high data rate like the transport stream and is used for transmitting data necessary for a real time transmission, and the asynchronous channel is used for transmitting and receiving a control command between equipments.
The link layer
202
multiplexes the isochronous channel and the asynchronous channel so that the host processor
201
can separate the data into isochronous and asynchronous data to process the data. The host processor
201
controls the link layer
202
to transmit and receive the isochronous and asynchronous data. The IEEE 1394 can also be implemented as a network between the equipments.
FIG. 3
is an example of a network utilizing the IEEE 1394 serial bus. For example, a digitized sound is transmitted as an isochronous data from a magnetic disk to a stereo interface, and a video image is transmitted as an isochronous data from a digital camera to a central process unit (CPU). Thus, two isochronous data are simultaneously transmitted between the stereo interface and the CPU. Such operation is available because the IEEE 1394 bus performs a multiplexation on the isochronous and asynchronous channels in a time-division multiplex structure as shown in FIG.
4
.
The multiplexation in
FIG. 4
is performed in cycles of 125 &mgr;s. Within each cycle, the isochronous channels must be transmitted according to a order of priority, and the asynchronous packets are transmitted in the remaining time.
FIG. 5
is a block diagram of a typical VSB-R
102
. A transport stream, ATSC MPEG-2 data packet, is input and stored in a buffer
501
. The input transport stream is then transmitted to a remodulator
502
at a necessary point in time. The remodulator
502
performs a radio frequency (RF) modulation based on an 8 VSB or a 16 VSB system as defined in the ATSC standard A/53 annex D. Thus, the remodulator
502
receives data from the buffer
501
and executes the VSB modulation. The VSB modulated transport stream input at this time may be multiplexed with an On Screen Display (OSD) data.
FIG. 6
shows a multiplexation structure of the OSD data defined in the VSB-R standard. The OSD data includes an OSD header and OSD data. Namely, the OSD header stores data such as a start position and size information of an OSD area, and palette information usable within the area. The OSD data stores bitmap information for all pixels provided within the OSD area. Thus the OSD data is converted into a packetized structure defined in the MPEG-2 standard. In other words, the OSD data is first packetized into a PES, and then re-packetized into a transport packet. Therefore, the OSD data is converted into a transport stream in two steps.
However, the digital apparatus of the future may require a several number of interface standards at the same time. As an example, the digital transmission standards of the IEEE 1394 and the VSB-R may be used in a digital broadcasting receiver as shown in FIG.
1
. In such case, it is currently impossible to perform a data exchange between the IEEE 1394 and the VSB-R. Namely, data input through the IEEE 1394 cannot be output through the VSB-R, and vice versa. This incompatibility is largely caused by different data transmission speed of the IEEE 1394 (200 Mbps) and the VSB-R (38.8 Mbps) and is also caused by different OSD transmission systems, thereby making it difficult to directly exchange data.
Therefore, when the IEEE 1394 and the VSB-R are both implemented within one digital apparatus, data cannot be transmitted from the IEEE 1394 to an equipment connected to the VSB-R, or vice versa.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to solve at least the problems and disadvantages of the related art.
An object of the present invention is to provide a format converting apparatus capable of converting a format of input data to allow exchange of data between an IEEE 1394 serial bus and a VSB-R.
Another object of the present invention is to provide a format conv
Chin Wellington
LG Electronics Inc.
Schultz William
LandOfFree
Format converting apparatus and digital broadcasting receiver does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Format converting apparatus and digital broadcasting receiver, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Format converting apparatus and digital broadcasting receiver will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3216363