GB2442779A

GB2442779A - External PC-CARD Conditional Access Module (CAM) digital television accessory.

Info

Publication number: GB2442779A
Application number: GB0620437A
Authority: GB
Inventors: Mark Anton Massel; Michel Guillien-Steinbach
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-10-14
Filing date: 2006-10-14
Publication date: 2008-04-16
Also published as: GB0620437D0

Abstract

The Digital Video Broadcast (DVB) PC-CARD (PCMCIA) interface is normally on a main PCB inside either a Set Top Box (STB) or digital Television. Here, the PC-CARD interface is, via a high speed electrical interface, at a distance in excess of 20 cm outside the STB or digital TV. The conditional access unit, for decrypting the video signal, may be connected to the receiver (STB) or TV by a USB 2.0 interface / cable. (The separate decoder unit can be sold by either the STB / TV manufacturer as an add-on product, or it can be bundled (sold with) the Conditional Access card by the encrypted service provider.) The DVB access-card accessory (a) with PC-card interface (e) is powered by an AC/DC converter (f1), and connected to digital receiver or STB (b) by USB cable (c). As shown in Figure 3, the device (a) comprises a USB (slave) controller (u), field programmable gate array (FPGA, g), and FIFO memories (j, p).

Description

DESCRIPTION

External PC-CARD Conditional Access Module (CAM) digital television accessory.

For the sake of brevity, the invention name, as stated above in the title, will be shortened to "PC-CARD accessory".

The PC-CARD interface specification has been modified by the Digital Video Broadcast (DVB) group for use in digital television applications. It is published under specification EN50221. In order for a television (TV) or Set lop Box (SIB) to be able to decode digital content that is encrypted, a Conditional Access Module (CAM) is plugged into this DVB PC-CARD interface.

The digital program stream, known as a Transport Stream (IS), from either a satellite, cable or terrestrial decoder is routed to come into the CAM and out again. If the end user has purchased a smart card (SC), then this plugs into the CAM. The CAM will then enable decoding of the digital program contents. This is shown in Figure 1. Note that the TS is a standard DVB data stream containing information about programming material, and also the video / audio data (either in the clear, ie no encryption, or in encrypted format) and related data such as teletext or program guide.

The video data is usually either MPEG-2, 1-1.264 or MPEG-4 compressed.

l'he DVB PC-CARD interface is normally on a main Printed Circuit Board (PCB) inside either the SIB or digital TV. One reason for this is that the interface must be close by the main digital processing electronics to avoid noise and therefore operational problems.

This invention puts the PC-CARD interface outside the STB or TV, hence making the TV or STB a lower price in the end market. The PC-CARD accessory can then be sold by either the SIB / TV manufacturer as an add on item, or it can be bundled (sold with) the Conditional Access card by the encrypted service provider, or any other third party. This invention pushes the additional cost associated with additional services (additional to what is normally transmitted as free programming) to the end user, hence making the basic SIB or TV equipment lower cost in the market, thus realizing a more competitive end product.

The invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows the typical block diagram of the main electronic components of the digital TV DVB processing as it is today. The complete system is part of a digital TV or SIB. Item b is the digital STB or digital TV PCB. Item q is the digital terrestrial, satellite or cable tuner and demodulator electronics. This outputs a digital Transport Stream (IS) which is shown as item n.

This feeds into a DVB PC-CARD interface which is shown as item e. The IS is then decrypted inside the Conditional Access Module (CAM'), shown as item s, provided that the Smart Card (SC), item t, is plugged in. The decrypted TS is shown coming out of the CAM as item o. This feeds into the main STB or digital TV processor (item r), which after doing the data de-compression / decoding and TV encoding, produces the audio and video signals for output to a TV for display. These signals are illustrated as item v.

Figure 2 shows an example of how the external connection is made to the PC-CARD accessory, in this example via a USB 2.0 interface, It is expected that more SIB systems will come into the market with USB interface and so this method of connection to the accessory is considered an important feature of this invention. Item b is again the TV or STB unit. This is shown connecting to the PC-CARD accessory item a via the USB cable (Item c). This can be any length, but typically greater than 20cm and less than 200 cm. Items d are the USB 2.0 connections. The PC-CARD interface is shown as item e. The PC-CARD accessory is also shown to require an external power source: Item fI is an A/C to D/C converter to provide a DC voltage since the USB connection will not be able to supply enough current for the PC-CARD accessory operation by itself. Note that item c can be replaced by a proprietary interface cable, whence items d then become proprietary connectors.

Figure 3 shows a more detailed block diagram of a USB 2.0 realized PC-CARD accessory, as will be explained here: The PC-CARD accessory is shown again as the main item a. It will be an enclosed PCB. It is realized as a slave device on a standard USB 2.0 interface. The USB interface is shown as item d, connecting to a USB (slave) controller chip shown as item u. This device communicates with a Field Programmable Gate Array (FPGA) device (item g), with control interface signals (item h) and a high speed data port (item i). IS data (suitably formatted) is sent from the digital TV or SIB to the USB controller device (item u), where, after some internal buffering and data processing is sent out onto the high speed data port (item i) to the FPGA (Item g). It is then fed, at a fast rate, into a First In First Out (FIFO) memory, shown as itemj, before being more slowly fed out into the PC-CARD interface (item e). The communications between the FPGA and the PC-CARD is via the standard DVB specified (EN50221) interface consisting of Data (item k), Address (item I), and Control (item m) lines. The TS data itself goes to the PC-CARD interface via the IS interface shown as item n. The CAM and SC (not shown in this figure) then perform their normal functions returning decrypted (or clear) audio and video data on the IS output (item o). This output is then again sent to a FIFO memory (item p), at a slow rate, prior to being fed out as a high speed burst of data to the USB 2.0 controller chip (item u), via the high speed data bus (item i). The USB controller chip then sends this data back to the main digital TV or SIB microprocessor, where the data is suitably formatted and decoded in the normal way as any normal MPEG-2, H.264 or MPEG-4 compressed stream would be. For completeness the PC-CARD accessory external power supply input is shown as item 12.

Claims

I. A DVB specified PC-CARD interface system that is physically, via a high speed electrical interface, a distance in excess of 20 cm away from, and therefore not inside, a set-top-box or digital television that requires it for de-scranibling of digital television content.
2. A DVB specified PC-CARD interface system according to claim I, in which the electrical interface can be USB2.O or another proprietary interface that allows the correct electrical functioning at a distance away from the main household equipment.
3. A DVB specified PC-CARD interface system according to claim 1, in which the said system can be purchased separately by an end consumer products purchaser to operate with the main set-top-box or digital television, by simply plugging it into either the USB2.0 interface or the proprietary interface of the set-top-box or digital television unit.