FAQ

 


DVB-H FAQs

1. What is DVB-H?
DVB-H is the latest development from the DVB Project targeting mobile live TV reception on handheld, battery powered devices such as mobile telephones, PDAs... Based on DVB-T's excellent mobile performance, DVB-H answers the need to ensure reliable, high speed, high data rate reception.

2. What are the differences between DVB-T and DVB-H?
DVB-H is an extension of the DVB-T specification for Digital Terrestrial Television Broadcasting. DVB-H addresses the constraints on power consumption and mobile reception inherent to mobile and portable platforms with the following technologies:

a/ Time-Slicing
Rather than continuous data transmission as in DVB-T, DVB-H employs a mechanism where bursts of data are received at a time based on an IP datacast. This means that the receiver is inactive for much of the time, and can thus, by means of clever control signaling, be 'switched off'. The result is a power saving of some 90% or more in general.

b/ 4K-mode
With the addition of a 4K mode with some 3409 active carriers, DVB-H benefits from the compromise between the high-speed small-area SFN capability of 2K DVB-T and the lower speed but larger area SFN of 8K DVB-T. In addition, with the aid of enhanced in-depth interleavers in the 2K and 4K modes, DVB-H has even better immunity to ignition interference.

c/ MPE-FEC
The addition of an optional, multiplexer level, forward error correction scheme means that DVB-H transmissions can be more robust. This is advantageous considering the hostile environments and poor (but fashionable!) antenna designs typical of handheld receivers.
 


3. Can DVB-H and DVB-T Networks co-exist?
Like DVB-T, DVB-H can be used in 6, 7 and 8 MHz channel environments. However, a 5 MHz option is also specified for use in non-broadcast environments. A key requirement, and a significant feature of DVB-H, is that it can co-exist with DVB-T in the same multiplex. Therefore an operator can choose to have 2 DVB-T services and one DVB-H service in the same overall DVB-T multiplex.

4. Can DVB-H be used on any frequencies?
DVB-H is not limited to use in typical DVB-T UHF networks but can be deployed using almost any available frequency (e.g. L-band-1.672 GHz and MMDS-2.5 GHz) and at scalable bandwidths (e.g. 1.5 MHz, 3.5 MHz, 4.5 MHz...). This makes DVB-H very flexible and therefore, attractive to potential network providers. 
 
5. How does DVB-H compare to mobile TV services in 3G and UMTS phone networks?
DVB-H is a broadcast technology. Broadcasting is an excellent way of reaching many users with a single (configurable) service. DVB-H combines broadcasting with a set of measures to ensure that the target receivers can operate from a battery and on the move, which makes it an ideal companion to 3G and UMTS telecommunications, offering symmetrical and asymmetrical bi-directional multimedia services.

6. What about competing technologies such as ATSC, ISDB-T and T-DMB?
Reception of multimedia services on mobile and portable devices is difficult to achieve. The basis for good reception starts with the underlying standard. This sidelines the single carrier (8-VSB) ATSC system from the US. ISDB-T, developed and now deployed in Japan, has a mode that could offer mobile datacasting services, but concerns about battery power, receiver cost and low bandwidth remain. T-DMB, the Korean DAB-based system does not offer a wide range of services due to inherent bandwidth limitations along with concerns about battery power, receiver cost. DVB-T is deployed in approximately 50 countries and, with DVB-H, now provides a powerful tool to address new markets for DVB services.
 
7. Why use DiBcom technology?
DiBcom has over 5 years of experience developing ICs for receiving digital television signals in mobile and portable environments.It is simply not enough to take a receiver designed for use in the home and expect it to work while in motion. DiBcom's patented technology addresses the constraints imposed on the receiver in mobile applications, namely echoes, fading, adjacent signal estimation/rejection and Doppler compensation. Our state-of-the-art technology developed for mobile DVB-T has now been incorporated into the world's first (and only) DVB-H demodulator chip.

DiBcom facilitates the development of DVB-T and DVB-H receiver products by providing Reference Design Kits including prototype board, interface boards and SDKs including drivers, test application software and documentation. Time-to-market is a critical factor and by using a DiBcom reference design, your company  is guaranteed a short development cycle.

DiBcom DVB-H demodulators are compliant with  the 'Proven Performance' receivers described in the DVB-H Reference Guidelines. The C/N is about 3dB better than the one of the 'Typical Receiver' offering 50% Network infrastructure cost reduction to Network operators. The Doppler compensation reaches 130Hz instead of only 80Hz for 'Typical Receivers' which allows Mobile TV in high speed trains even in L-band.

8. Is this the first time DVB-H is being deployed in the US?
    What other countries have deployed DVB-H?
Modeo / Crown Castle International Corp. (NYSE: CCI) is currently holding DVB-H trials in the US, specifically in Pittsburgh. Based on the success of the trials , we expect DVB-H to be deployed in other US regions in early 2006. DVB-H has been successfully tested in various European, Asia Pacific countries including Italy, Germany, France and China. If countries currently support the DVB-T standard  - the conversion to DVB-H is a quite simple transition.