The document discusses proposed extensions to the DVB-S2 digital video broadcasting standard over satellites. The extensions aim to improve spectrum efficiency and allow for higher data rates. Key points include:
1) Reducing roll-off factors and side lobes of carriers allows transponders to be placed closer together, utilizing bandwidth.
2) Using wider bandwidth transponders that are 3 times the size of typical ones further increases efficiency.
3) A new 64-APSK modulation scheme and additional coding options provide more flexibility to optimize throughput.
4) Overall, the extensions could provide up to 20% higher data rates for broadcasting and 64% for professional services.
Radio over IP (RoIP) is a technology that has emerged over the last 10 years and has provided a powerful and flexible mechanism for linking radios and dispatch consoles. RoIP has some inherent limitations and numerous technical challenges. This workshop will provide an overview of the technology, the key standards and some of the technical issues.
The workshop will cover on the following issues:
- The difference between RoIP and VoIP — how radio systems differ from phone systems
- Implementing one-to-one connections
- Implementing many-to-many connections
- Risk management: identifying network issues affecting RoIP/VoIP quality, maintenance and redundancy
- Design elements: building blocks; calculating network bandwidth requirements
The implications of RoIP for dispatch consoles will be also be discussed: how dispatch console to radio connections can be implemented with RoIP and how RoIP can be used to provide fault-tolerant dispatch architectures.
Finally, the workshop will look at the impact of new technologies such as IPv6, wireless broadband and the switch to digital radio on the RoIP landscape.
Paul Whitfield, Team Leader: Software Engineering, Omnitronics
We take pride in introducing ourselves to your esteemed organization. We are engaged in the business of providing Walkie Talkie and other Telecom and Security Solutions to our clients.
We are capable of giving all types of telecom spares with respect to Walkie Talkie and other Telecom and Security Products, viz: Telephone Handsets, Cords, Batteries, PTTs, Hand Held Metal Detector Chargers and Batteries, Door Frame Metal Detector Spares, etc. We do undertake maintenance contracts of various equipment with our staff of Technical Engineers and Technicians.
Radio over IP (RoIP) is a technology that has emerged over the last 10 years and has provided a powerful and flexible mechanism for linking radios and dispatch consoles. RoIP has some inherent limitations and numerous technical challenges. This workshop will provide an overview of the technology, the key standards and some of the technical issues.
The workshop will cover on the following issues:
- The difference between RoIP and VoIP — how radio systems differ from phone systems
- Implementing one-to-one connections
- Implementing many-to-many connections
- Risk management: identifying network issues affecting RoIP/VoIP quality, maintenance and redundancy
- Design elements: building blocks; calculating network bandwidth requirements
The implications of RoIP for dispatch consoles will be also be discussed: how dispatch console to radio connections can be implemented with RoIP and how RoIP can be used to provide fault-tolerant dispatch architectures.
Finally, the workshop will look at the impact of new technologies such as IPv6, wireless broadband and the switch to digital radio on the RoIP landscape.
Paul Whitfield, Team Leader: Software Engineering, Omnitronics
We take pride in introducing ourselves to your esteemed organization. We are engaged in the business of providing Walkie Talkie and other Telecom and Security Solutions to our clients.
We are capable of giving all types of telecom spares with respect to Walkie Talkie and other Telecom and Security Products, viz: Telephone Handsets, Cords, Batteries, PTTs, Hand Held Metal Detector Chargers and Batteries, Door Frame Metal Detector Spares, etc. We do undertake maintenance contracts of various equipment with our staff of Technical Engineers and Technicians.
Beyond four times (4K) the resolution of High Definition (HD) video, true Ultra HD (UHD) delivers a more immersive
viewing experience, boosting picture detail and sharpness, as well as providing more realistic and richer colors.
Until recently, the UHD market has mainly been driven by TV manufacturers. Now it is set to expand, providing
opportunities for the whole value chain from content suppliers through to service providers and equipment
manufacturers.
But with capacity already at a premium due to trends like HD video generating high bitrate streams, is the satellite
industry ready to cope with a UHD world?
Content distribution to professional users can be easily combined with DTH. As video content is abundant in the video headend, it’s the right place for distributing content rights to, for example, cinema venues via file transfer. This Solution Overview details
how the ST Engineering iDirect’s M6100 Broadcast Satellite Modulator, the MCX7000 Multi-Carrier Satellite Gateway and the Dialog® platform support these three aspects of DTH.
Digital broadcast systems have increasingly been deployed for various services such as
Digital Video Broadcasting (i.e. DVB-S, DVB-T, etc.) and Digital Audio Broadcasting (DAB). Classical
digital broadcast systems were designed with fixed modulation techniques, which had to guarantee
reliable communication even with very hostile channel environment. Video Broadcasting is playing a
key role in communication areas. In this paper DVB-T (terrestrial based digital video broadcasting) based
OFDM is analyzed in terms of various parameters for 2K mode.
Keywords:- Digital video broadcasting, DVB-T, orthogonal frequency division multiplexing, OFDM
HIGH SPEED CONTINUOUS-TIME BANDPASS Σ∆ ADC FOR MIXED SIGNAL VLSI CHIPSVLSICS Design
With the unremitting progress in VLSI technology, there is a commensurate increase in performance demand on analog to digital converter and are now being applied to wideband communication systems. sigma Delta (Σ∆) converter is a popular technique for obtaining high resolution with relatively small bandwidth. Σ∆ ADCs which trade sampling speed for resolution can benefit from the speed advantages of nm-CMOS technologies. This paper compares various Band pass sigma Delta ADC architectures, both
continuous-time and discrete-time, in respect of power consumption and SNDR. Design of 2nd order multibit continuous time band pass Σ∆ modulator is discussed with the methods to resolve DAC non-idealities.
This Solution Overview gives an overview of the most common Digital Terrestrial Television (DTT) primary distribution
architectures involving satellite. Attention is paid to the role of efficient usage of the satellite payload in order to minimize OPEX costs.
An increasing amount of TV channels, transmitted at higher
quality, creates the need for a higher efficiency transmission. The DVB-S2X standard fuels growth in revenues and lower OPEX by up to 30%.
1. معايير جديدة لبث الفيديو الرقمي
•تحسينات جديدة تسمح بمعدالت بيانات أعلى
•اطياف النواقل األكثر استطالة تقدم مساحة لنواقال اضافية
•تقليل الهوامش الجانبية يعطي المزيد من المساحة لمزيد من
النواقل
•نواقل النطاق العريض تضيف للفعالية
•تعديل جديد بمعدل 6 بت
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خاصية
امتدادات للجيل
الثاني لبث الفيديو
الرقمي عبر األقمار
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2. FEATURE
New DVB Standards
What‘s coming next
after DVB-S2?
Jacek Pawlowski
The DVB-S2 standard was first published in 2005. While the performance
it offers may still impress us nowadays,
the advances in technology and growing demand for higher and higher data
rates make the satellite industry search
for even more efficient ways to transfer
huge amount of data most notably the
high demands generated by Ultra High
Definition TV (UHDTV) and high speed
IP services over satellite.
Recently in TELE-audiovision 0708/2013 we have published a feature
articles about the new UHDTV standard
and the video compression standard
HEVC, also known as H.265 – a successor of MPEG-4 (H.264). These new
solutions require new hardware and
software. It makes a good moment to
improve also the modulation, coding
and error correction standard as defined by the DVB-S2 standard.
As the proposed improvements have
not yet been blessed by the DVB organization we will call them the proposed extensions to DVB-S2. However,
real hardware devices have been built
and various test have been performed
to prove these new concepts. These
new DVB-S2 extensions are labelled as
DVB-S2EB1, DVB-Sx or even DVB-S3
although such a standard does not yet
officially exist in this moment.
The proposed extensions can give a
20% increase in data rate compared
to DVB-S2 in DTH (Direct-To-Home)
broadcasts. For professional services,
like VSAT communication, the gain can
be as high as 64%.
So, what exactly are these extensions? Here is our list:
- reduction of the roll-off factors and
the side lobes of digitally modulated
carriers
- use of wide bandwidth transponders
- additional modulation: 64 APSK
- more modulation and coding (MODCOM) schemes and forward error correction (FEC) choices and non-linear
MODCOMs
Not all of the extensions are easy to
■ Figure 1. With smaller roll-offs, transponders can be squeezed closer to one another.
■ Figure 2. Reducing side lobes by more efficient filtering contributes to better bandwidth utilization.
comprehend but in this features article
we try to help you to get a general idea
on most of them.
The roll-off factor describes the
shape of the transponder spectrum as
seen on a spectrum analyzer. Its value
tells you how close to an ideal rectangular the spectrum is. The smaller it
is the more steep are the slopes of a
transponder spectrum. DVB-S requires
a roll-off of 35%, DVB-S2 of 20% and
25% while the the proposed S2 extensions aim at 15%, 10% and 5%. It is
easy to understand that with smaller
roll-offs one can position transponders
closer to one another in the frequency
domain and gain a free space for additional ones in the same Ku-Band or
C-Band.
However, not only (relatively) big rolloffs prevent closer location of the DVBS2 transponders. So called side lobes
are normally present on both sides of
the useful signal. These are unwanted
artifacts after modulation. With today’s
technology it is possible to practically
get rid of them thanks to improved
filtering. Once they are removed, the
center frequencies of the neighboring
transponders can be set closer to one
another.
If you take a look at Figure 2, you can
come to the conclusion that even after removing side lobes and improving
same bandwidth but the signal is more
sensitive to interference and noise. 64
APSK will be used in professional setups with large antennas rather than in
DTH transmissions.
Probably the same goes true for the
last extension mentioned in the beginning of this article: more MODCOM and
FEC values. These parameters generally describe how big overhead is introduced in the data stream to the useful payload. The overhead in bit rate is
needed for error correction. Once we
have more possibilities here, we can
almost smoothly change the proportion between useful and corrective bits
in order to find a minimum overhead
still ensuring faultless processing. Such
roll-offs, there is still some spectrum
wasted between the transponders. And
that’s why wideband transponders are
the next trick in improving efficiency.
Their throughput is increased to 72 Ms/
sec. When compared with the most
popular 27.5 Ms/sec transponders, the
wideband ones are three times wider in
spectral view.
Every new DVB standard introduces a
new modulation schemes. DVB-S2 ended up with 32 APSK. The proposed extensions call for 64 APSK. In this modulation, every symbol is made up of 6
bits. Of course, the higher the order of
modulation, the smaller the differences
in amplitude and phase between similar
symbols. We can send more data in the
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thing is possible when we have a pointto-point two-way communication. In
case of a reception problem, the system automatically adjusts MODCOM/
FEC.
Also the wideband transponders
described above require the reception system to be of a higher performance because the carrier-to-noise
ratio degrades proportionally with the
bandwidth increase. The best way to
maintain a good C/R is to use a bigger
dish. Therefore, it is not certain if wideband transponders will be used for DTH
broadcasts. After all, not too many end
users will be eager to replace their 6090 cm dishes with larger ones.
That’s why the experts assume that in
DTH transmissions only about 20% increase in the efficiency is realistic while
in professional links even 64% would be
possible. Anyway, we can not say today
which particular extension proposals
will be included in the eventual settlement of the DVB-S3 standard. Maybe
only some of the above, maybe all of
them. We will not be surprised though
if brand new concepts are worked out
in meantime and included in the new
standard.
One thing is for sure: the improvements will enable higher useful data
rates in the existing satellite communication channels and this will be an
important factor enabling UHDTV and
other wideband services.
Wideband transponder
■ Figure 3. Wideband transponders use frequency spectrum more efficiently.
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