SEMINAR REPORT On
DIGITAL HUBBUBSubmitted by :ABHIJEET MUKESH
COMPUTER SCIENCE & ENGINEERING
SCHOOL OF ENGINEERING
COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY,
COCHIN â€œ 682022
SEPTEMBER 2008 2
DIVISION OF COMPUTER SCIENCE & ENGINEERING
SCHOOL OF ENGINEERING
COCHIN UNIVERSITY OF SCIENCE &
TECHNOLOGY, KOCHI â€œ 682022
The latest talk in the consumer electronics industry is about digital hubbub. This device is used as a hub to interconnect various any home devices. Along with the interconnecting capability hub also incorporates several functions like recording, play backing etc of data streams from various electronic devices in the house. The electronic devices mentioned include a TV, VCR, Camcorder, personal computers etc. The digital hub would be expected to access high-capacity storage and data access devices provide and inputs for devices such as TV tuner, digital cameras, digital video, and broadband digital data. Apart from this it must be capable of distributing these files and information using connection mechanisms like a cable or digital subscriber line (DSL) modem on the front end of the hub. Additionally an efficient user interface is a must and should be a file browser like that of a PC desktop, modified for a TV screen, and a remote control to provide a familiar interface and ease of access. How does the Digital Hubbub system manage to solve all these challenges? What forms the internal core components of the Digital Hubbub system? Various disparate technologies will need to be married into a single device to provide control and connectivity features in an efficient manner. Another facet of the Digital Hubbub system is the Software. What will be the design of the component? The functionality of the system will directly depend on the design and power of the software layer. What will determine the future of the Digital Hubbub technology? The need for a uniform standard for product development among the product engineers is just as important as the actual device itself
Human being is always looking for single device that can be used for various purposes. We can connect various devices either it is the case of personal computers or home devices that we use in our day to day life. Interconnection is for easy accessing of information or data stored on other devices. This is fine when we are connecting the PCs but when you talk about house devices such as TV, VCR, Cam recorder, personal computers etc. It looks pretty odd. We are very much familiar about Hub. Hub is electronic device that connect Small office, home office (SOHO) applications typically use a single Hub, or an all-purpose converged device such as gateway access to small office/home office broadband services such as DSL router or cable, Wi-Fi router. We have something same device faster in comparison with hub that is Switch. A lot of innovations are taking place in the field of consumer electronics. The latest talk is about a single device which can interconnect all these entertainment devices and provide many functions such as record, archive, and playback music and videos, organize digital photo and albums, and distribute signal media around the home. So companies gave birth to a new electronic device which is known as DIGITAL HUBBUB. his device is used as a hub to interconnect various any home devices .Along with the interconnecting capability hub also incorporates several functions like recording play backing etc of data streams from various electronic devices in the house . The electronic devices mentioned include a TV, VCR, Camcorder, personal computers etc. The hub consists of a software part and hardware part. Hardware comes along with CPU. It has Digital signal processing chips in a memory and different ports for interfacing. Hard disk drive, Universal Serial bus port, PCMCIA and Ethernet jack are also core of hubbub. Software has got 3 layers an inner layer, a middle layer and an outer layer. These layers are divided on the basis of various functions they have to do. To Apple and Microsoft, it looks like a computer. To cable and satellite companies like Charter, EchoStar, or DirecTV and their suppliers, it's a set-top box. To consumer electronics companies like Philips or Samsung, it's a stereo component. Various companies are now trying to make their dream possible, as a company which brought digital hubbub. Some of the companies like Moxi digital (Palo Alto, California), Digeo Inc. (Kirkland, Washington), Motorola Inc. (Schaumburg, Ill.) and cable company Charter Communications Inc. (St. Louis, Mo.) are interested in building boxes that include high-speed data connections and home-network capabilities, in addition to the digital TV decoders of ordinary cable systems.
2. Hub as a Factotum
Factotum means an employ that does a lot of things. This is what digital hubbub does by recording, archiving, store digital photos and albums and distribute digital media around home. This can be done from sources like CD library, broadcast TV, and the internet. They will also be able to store and play video games. And they will organize all your media files in an easy-to-browse fashion and play them back on demand, making available features such as pause, rewind, and several varieties of skip and fast-forward. Typically, the digital hub would be expected to access high-capacity storage and data access devices provide and inputs for devices such as TV tuner, digital cameras, digital video, and broadband digital data. Apart from this it must be capable of distributing these files and information using connection mechanisms like a cable or digital subscriber line (DSL) modem on the front end of the hub. Additionally an efficient user interface is a must and should be a file browser like that of a PC desktop, modified for a TV screen, and a remote control to provide a familiar interface and ease of access On the output side, a digital hub would serve audio and video to every TV set, computer, and stereo in your home .This would require a wiredâ€or preferably wirelessâ€ network, with cheap receivers scattered around the house to capture the digital signals and return them to analog form. Inside, a hub may look much like an oddball PC from the last decade: a 32-bit CPU ticking over at a few hundred megahertz, with some multiple of 8MB of RAM, a video interface, and a digital signal-processing (DSP) chip or two to compress and decompress the video and transform the stored data into a format for display. It will also need 20GB of disk space and up, as good video requires about a gigabyte an hour, and audio needs about a megabyte a minute. (Once you have the CPU and DSP chips for encoding and decoding the streams of digital video compressed for broadcast or storage on a DVD, most of the other functions of a home entertainment gateway, including the user interface and music storage, are close to free).
TV, VCR, Digital camera etc. are connected by cable wire or wireless. Wireless network is done by connecting devices by cheap receivers. All heavy appliances are connected to hubbub via home network while light appliances are connected directly to hubbub by USB ports.
3. Under The Hood Under this heading we deal with the elements which make up digital hubbub. Just like a personal computer it also got a hardware side and a software side is same way it has also two parts.
• At the core of a hubbub is
• Central Processing Unit
• Digital signal processing chips
• Hard disk drive
• Universal serial bus port
• PCMCIA connector
• Ethernet jack
Central processing unit: - As in a computer system, CPU is the master of the hub. It deals with the data transfer that takes between different peripherals and hub. It checks on the parallel operations taking place in hub. It enroutes data packages to different operating units. It receives signals regarding the function to be done from the control panel or from a remote control Functions are like recording a video or writing an MP3 in a CD or retrieving the stored data. Based on the received signal the central processing unit generates signals which control other peripherals to perform the concerned operation.
Digital signal processing chips: - The analog signals from various peripherals like a TV set or a tape recorder is received by analog to digital convertors. These digitized data is accessed by digital signal processing chips via their serial ports. These data streams are compressed for storage .For displays these stop data is expanded by the same digital signal processing chips. This processor has parallel operating functional units and this help in real time processing of data.
Hard Disk Drive: - The hard disk drive is under a direct control of CPU via disk controller. As in any device a hard disk drive is used to store the data .The compressed data from the digital signal processing chips is written onto the hard disk drive and for displays the same data is accessed via CPU. It will require a capacity of several giga bytes even more than a 20 GB because a good video require a giga byte for an hour and good audio needs about a megabyte a minute.
Universal Serial Bus (USB): - The USB is a synchronous protocol that supports isochronous and asynchronous data and messaging transfers. This universal serial bus port is used to communicate data with portable MP3 music players, digital cameras etc.
Personal Computer Memory card International Association (PCMCIA):- PCMCIA cards are credit card size adapters which fit into PCMCIA slots found in most handheld and laptop computers. This is also known as PC card. PC Card was originally designed for computer memory expansion; it soon became apparent that this same interface could be used to add I/O devices and hard disk drives. These cards are not used for expansion of memory but also can be used for wireless connectivity, modem and other functions in laptop/notebook PCs that may be lacking them natively. In order to fit into these small size drives, PCMCIA cards must meet very strict physical requirements. It is used in transferring data with non volatile memory cards or other devices.
Ethernet Jack: - Hub requires communication with other personal computers as in a local area network. Ethernet jack is the hardware used for the above said interface. As the function of different unit are described in above heading. Fig. 3.1 clearly shows the units inside hubbub.
A Magnifying Look On
3.1.1 DSP Processor
DSP Processor used in Hubbub is enhanced version of A236 video DSP chip i.e.A436 Parallel Video DSP chip. Oxford Micro Devicesâ„¢ Ax36 of video digital signal processing chips is highly optimized for handling live images and being programmed directly in C .
1.Highly optimized and efficient, general purpose, very high performance, 512b advanced imaging parallel DSP and 32b RISC processor (no MMU) in a single chip in a single instruction stream.
2.Achieves very high performance with moderate CPU clock rate and main-stream fabrication.
3.Fully C software-programmable, parallel image processor optimized for real-time
4. Much faster, more efficient and easier to understand, optimize and use than other fast DSPs.
5. Directly software programmable in C as universal compressor encoder)/decompressor (decoder) for multi-format.
6. Provides fully software programmable video compression in real-time.
7. Enhanced version (fourth generation Ax36 core) of proven A236 Video DSP Chip.
8. Easy to program - use C not microcode!
9. Full software development environment includes C compiler, assembler, linker, loader, simulator and debugger
10. Develop code using our parallel-enhanced ANSI-standard C compiler with assembly language output
11. Three internal DMA controllers automatically build circular, multi-frame image/video buffers with programmable sizes in memory, providing a standardized format for video capture, processing and display
12. uCLinux RTOS(real-time operating system) with TCP/IP and UDP/IP for Internet connectivity, and file system and device drivers (video input/output, IDE, USB, Ethernet, PCMCIA) .
3.1.2 USB Bus
The motivation behind the selection of USB for the Macintosh architecture is simple.
1. USB is a low-cost, high-speed peripheral expansion architecture that provides data
transfer rates up to 12 Mbps.
2. The USB is a synchronous protocol that supports isochronous and asynchronous data and
3. USB provides considerably faster data throughput for devices than does the modem and printer ports. This makes USB an excellent replacement solution for not only the existing slower RS-422 serial channels but also the Apple Desktop Bus, and in some cases slower speed SCSI devices.
In addition to the obvious performance advantages, USB devices are hot pluggable and as such provide a true plug and play experience for computer users. USB devices can be plugged into and unplugged from the USB anytime without having to restart the system. The appropriate USB device drivers are dynamically loaded and unloaded as necessary by the Macintosh USB system software components to support hot plugging. Some of comparisons between USB and FireWire is that USB was originally seen as a complement to FireWire (IEEE 1394), which was designed as a high-speed serial bus which could efficiently interconnect peripherals such as hard disks, audio interfaces, and video equipment. USB originally operated at a far lower data rate and used much simpler hardware, and was suitable for small peripherals such as keyboards and mice. The most significant technical differences between FireWire and USB include the following:
• USB networks use a tiered-star topology, while FireWire networks use a repeater-based topology.
• USB uses a "speak-when-spoken-to" protocol; peripherals cannot communicate with the host unless the host specifically requests communication. A FireWire device can communicate with any other node at any time, subject to network conditions.
• A USB network relies on a single host at the top of the tree to control the network. In a FireWire network, any capable node can control the network.
• USB runs with a 5 V power line, whereas Fire wire can supply up to 30 V. 16
10.These and other differences reflect the differing design goals of the two buses: USB was designed for simplicity and low cost, while FireWire was designed for high performance, particularly in time-sensitive applications such as audio and video. Although similar in theoretical maximum transfer rate, in real-world use, especially for high-bandwidth use such as external hard-drives, FireWire 400 generally, but not always, has a significantly higher throughput than USB 2.0 Hi-Speed. The newer FireWire 800 standard is twice as fast as FireWire 400 and outperforms USB 2.0 Hi-Speed both theoretically and practically. The chipset and drivers used to implement USB and Fire wire have a crucial impact on how much of bandwidth prescribed by the specification is achieved in the real world, along with compatibility with peripherals. Audio peripherals in particular are affected by the USB driver implementation. One reason USB supplanted FireWire, and became far more widespread, is cost. FireWire is more expensive to implement, resulting in more expensive hardware. Features:
1. Better Device Expansion Model:-The USB specification includes support for up to 127 simultaneously available devices on a single computer system. (One device is taken by the root hub.) To connect and use USB devices, it isn't necessary to open up the system and add additional expansion cards. Device expansion is accomplished with the addition of external USB multiport hubs. Hubs can also imbedded in USB devices like keyboards and monitors which provides device expansion in much the same way that the Apple Desktop Bus (ADB) is extended for the addition of a mouse through the keyboard or monitor. However, the USB implementation won't have the device expansion or speed limitations that ADB does.
2. Compact Connectors and Cables:-USB devices utilize a compact 4-pin connector rather than the larger 8- to 25-pin connectors typically found on RS-232 and RS-422 serial devices. This results in smaller cables with less bulk. The compact USB connector provides two pins for power and two for data I/O. Power on the cable relieves hardware manufacturers of low- power USB devices from having to develop both a peripheral device and an external power supply, thereby reducing the cost of USB peripheral devices for manufacturers and consumers.
Founded in 1990, the Personal Computer Memory Card International Association (PCMCIA) was developed a set of standards by which additional memory could be added to portable systems. This is also known as PC card as well as its successor Express Card. PC Card was originally designed for computer memory expansion; it soon became apparent that this same interface could be used to add I/O devices and hard disk drives as well, thereby dramatically increasing functionality of laptop computers. Although this refers to memory cards, but their standards are not limited to memory devices. These cards can be used for wireless connectivity, modem and other functions in laptop/notebook PCs that may be lacking them natively.
The PCMCIA specification 2.0 was released in 1991 and added protocols for I/O devices and hard disks. The 2.1 release in 1993 refined these specifications, and is the standard around which PCMCIA cards are built today. PCMCIA cards are credit card size adapters which fit into PCMCIA slots found in most handheld and laptop computers. In order to fit into these small size drives, PCMCIA cards must meet very strict physical requirements as shown in Figure 3.2. There are three types of PCMCIA cards. They are as follows:-
1. Type I feature a 16-bit interface. They are 3.3 mm thick and generally used for memory cards such as FLASH, OTM, RAM and STATIC RAM.
2. Type II features a 16- or 32-bit interface. They are 5.0/5.5 mm thick and used for I/O peripherals such as serial adapters, parallel adapters, and fax-modems.
3. Type III cards are 16-bit or 32-bit. These cards are 10.5 mm thick, allowing them to accommodate devices with components that would not fit type I or type II height, which are used for rotating media such as hard disks. The only difference in the physical specification for these cards is thickness. Fire wire and USB devices are available for almost all functions that the PC Card interface was used for in the past, although it retains the advantage of containing devices entirely or almost entirely inside the case of the portable device. This can be an important consideration for portable systems, where additional external peripherals and their associated cables, space, and sometimes additional power supplies can reduce portability and convenience. However, even in this case Express Card devices have the same advantages as PC Card devices, with additional bandwidth & functionality. On the other hand many devices do not need the speed of PCI Express, and often PC Card devices with adequate performance can be found cheaply, as discounted new parts or on the used components market, and will suffice for many users' purposes.
As in a normal personal computer we have software that describes a collection of various programs procedures and documentation of some tasks. It checks on user interface, applications etc. with hardware. Software of digital hubbub can be considered as a series of layers. These layers are as follows:-
1.Innermost Layer: - In the innermost is an operating system that manages resources such as storage or CPU timing.
2. Middle Ware Layer: -The middle ware that handles such house keeping details as displaying text and graphics on TV screens. The middleware interpret the input from different panel or remote control and it enables the CPU to generate signals according to the concerned function. It also deals with the communication with the cable that supplies the digital video and data strings.
3. Outermost Layer: - The outermost layer handles several applications .These applications includes recording controls program guides and onscreen signup for additional services and games and even web browsers. It provides a search engine that with only a few button pushes could find all movie musical starring, for instance Elvis Presley, or action dramas with Jackie Chan, or new episodes of your favorites home improvement show. Software for digital hubbub is provided by mediabolic Inc. (SAN FRANCISCO).
4. Neologism in The success of any product relies on the compactness and cheapness of the product. As any electronic device digital hubbub is also required to be compact and cheap. Compactness is brought about by implementing chips with multi-functions or in other way it can be said as compactness can be brought by merging 2 or 3 chips to do a single function. Therefore several electronics firm are doing lot of research and development to bring about a much compact and cheap digital hubbub. A few affords to make the digital hubbub compact and cheap are as follows:
1.Conexant Systems Inc. (Newport Beach, Calif., formerly Rockwell Semiconductor Systems) announced a chip that combines digital TV reception with a cable modem. It lets cable operators sell broadband interactive services in a low-cost package that includes 100- plus TV channels.
2. Cirrus Logic Inc. (Austin, Texas) has among its chips a combined DVD and digital-video chipset that powers Samsung's PVR.
3. Linksys Group Inc. (Irvine, Calif.) is known for its pocket routers (units that connect small home or office networks to the Internet), it has a new chip that combines routing circuitry with a cable modem and a wireless network access point. Such a chip could be built into a stand-alone digital hub or slotted into a PC acting as a home server.
4. PVR maker TiVo Inc. (Alviso, Calif.), engineered into its custom disk-controller chip. The chip can read data streams from the disk surface in whatever order is most efficient for the head and then reassemble the information before handing it off to the video section. Meanwhile, the price of hard-disk drives has put enormous volumes of storage within reach of even a run-of-the-mill set-top box. Currently, a 40-GB drive, which stores more than 50 hours of video, is very less wholesale. Even a small fraction of that disk space can store dozens of hours of audio and thousands of digital photos.
5. The Evolving Interface The interface looks like TiVoâ„¢s where you peck out the name of the show on a virtual on- screen board: as you type each letter, an adjacent display of potential matching titles gets shorter until only a few choices remain. Once the right show is found, recording its episodes is a matter of pressing just a button or two.
Mox is simplifying matters further by mapping the letters most likely to be typed next to the numbers 1 through 9 on the remoteâ„¢s keypad. Typing text on a numeric keypad will be familiar to the millions of people who send text messages by cellular phone. Here Figure 5 is t9 dictionary used in Sony Eriksson mobile as we are looking when we are writing any word character is potentially match with other words stored in dictionary in same way searching is done in hubbub. It helps in faster searching of data.
6. Dream versus reality Any build-up to a single home gateway that controls your television, air conditioning, and e-mail will not come overnight. People won't replace their VCR, DVD player, and home network all at once. Thus far, there are barring a few exceptions such as "universal" remote controls and serial control inputs for some cable boxes. Manufacturers focus on locking consumers into a single supplier. Thatâ„¢s why we look for devices which should be compatible with digital hubbub. If not compatible, then consumer cannot afford to buy such devices which are compatible with hubbub. Whether that philosophy can stand up to the ultimate purpose of a digital hubâ€connecting all the disparate entertainment devices a consumer may own and even replacing some of themâ€is probably the crucial question for the evolution of this new technology.
The Digital Hubbub technology has the potential of revolutionizing the way people will access devices. As Technology advances at a rapid pace, there are barriers that will impede the integration of all our needs into a single platform or device. Even if technology was to overcome all barriers and we were really able to produce an all-in-one device, people will not want it. Why? Simply because people have a choice: and it comes down to user interface, convenience and security. Letâ„¢s take the convergence of internet with mobile phones. Wireless networks catering to this service are slow, and most sites are not optimized to mobile screens. Your fingers will tire if your eyes and patience do not give out first. Introducing a single home gateway that controls everything from a television, air conditioning, to e-mail will not come overnight because people will not want to replace their favorite VCR, DVD player, and home network devices and that too all at once. Since the development of this technology is a nascent stage it provides a lot of scope for computer science engineers like us for research and areas of study. The philosophy of digital hubbub which aims at uniting disparate devices allows infinite possibilities of convergence and a vast scope for creativity. This field will dominate the electronics industry in the years to come and gives a glimpse into the kind of work we will be doing in future.
1. Oxford Micro Devices, Inc. Summary of A436 Parallel Video DSP Chip, June2001.
2. Paul Wallick, Digital Hubbub, IEEE Spectrum, July 2002, pp 26-31