I use my VisionPlus DVB-T card for Digital SDTV and HDTV combined with the TSReader software and the free software VLC.
Streaming is done (by default) over RTP/UDP over IPv4 or IPv6 unicast or multicast.
The problem is, with 802.11g, it does not seem to be able to reliably deliver an SDTV signal (~7mbps here in Australia) let alone a HDTV signal (~14mbps). SDTV works sometimes, however can start to break up after a while, and I have to return to 100/1000 Ethernet.
Digital TV in Australia isn't worth bothering about
You certainly share my thoughts in some respect - although most content is at least 16x9 SD, in the cities at least, the digital signal does show up a lot of poorer editing processes and artifacts during the production process.
On the other hand, in Melbourne and Brisbane we have 1080i HD (@1920x1080) and that looks absolutely stunning on some programs, and movies.
The 'orthogonal' component is referring to the spreading codes used in the multiplexing component. It means the spreading codes have zero cross-correlation. This form of CDMA has essentially two components - the actual mapping of bits to symbols (i.e. QAM, QPSK, etc) and then increasing the bandwidth of a signal, summing it with all other channels originating from the same device (i.e. control channels, voice channels, etc), and then scrambling it.
The actual baseband carrier is 'spun' in both amplitude and phase (and thus indirectly by the laws of frequencies, frequency) by the multiplication of the complex number. In the case of QAM-16 for example, a constellation of 16 points in the complex plane will correspond to each possible 16 values of 4 bits. When those bits are sent to the transmitter, it looks up those bits in the constellation, which corresponds to some complex number a+bj (which conseqently spins the phase of the carrier by arctan(b/a) radians, and multiplies the amplitude by sqrt(a^2+b^2).
At this point the 'modulation' effectively ends and the 'multiplexing' takes over. However, the multiplexing is quite closely integrated with the modulation process.
It's important to remember that in a CDMA system, the complex symbols are not modulated directly to the carrier. In the case of UMTS for example, they are first spread into a series of complex chips by a real-valued spreading sequence they might looks something like
{ {-1, 1, 1, -1} {1, 1,1 -1}...}
for a spreading factor of 4 (which maps each symbol into a sequence of 4 chips).
Then the chips are scrambled by a complex-valued scrambling code which is typically generated by some PN-derived sequence such as a Gold code. The scrambling code does not increase the bandwidth of the signal, unlike the spreading code.
Shannon's Law states the maximum error free digital bandwidth b bits/s of an a slice of spectrum c Hz wide is:
b = c.log2(1+s)
Where s is the signal-to-noise ratio. Thus, in this case, where b=300000000 and c=100000000 s = 7, or 8.5dB, not an unrealistic expectation.
Of course, no current form of error correction coding approaches the ideal Shannon's Law, however reasonably recently developed Turbo Codes have come reasonably close.
The sort of modulation/multiplexing technique they would be using is a Wideband CDMA technique, similar to that used by UMTS and CDMA2000 wideband technologies.
Putting it simply, the bits are mapped onto a constellation in the complex plane which rotates and changes the amplitude of the carrier. The signal is spread using 2 codes - an Orthogonal code which has poor autocorrelation properties (but ideal cross-correlation properties across codes - hence the orthogonal term), and finally a PN sequence which has excellent autocorrelation properties.
I'm not too familiar with this technology, but I can make some guesses how they might have gained speed improvements over UMTS would be:
- Very wideband - 100MHz vs 5MHz - More precise QAM (Quadrature Amplitude Modulation) - UMTS allows upto QPSK (2 bits per symbol) or QAM-16 (4 bits per symbol). Perhaps this technology has extended this QAM-64 (6 bits per symbol).
It's a shame it looks to be analog only. Especially with the amount of Widescreen Digital and High definition content being broadcast in areas of Australia.
These were the questions I asked. I intended to setup a website for Australian mobile phone users - since no such website really existed.
We spent several weeks researching hosts and experimenting with content management systems. This is what we ended up with:
Hosting - Shared hosting at Hostony.net. For around US$8/month, we got 1000M of space and around 35G of bandwidth, as well as the services we needed - such as MySQL databases, SSH, FTP, etc.
Choosing hosting was difficult - as not everyone offered all the features we needed - common problems were limitations on SQL databases, small space quotas, as well as setup fees when only on short term bill (we wanted preferably monthly payments so we could pull out whenever we needed if necessary. In the end we settled on 3 monthly payments).
Unfortunately the hosting service was unreliable - with many server reboots, timeouts, and complete outages. After complaining we were moved to a better server, which has delivered better performance (but still not up to scratch).
Content Management - we chose Postnuke and PhpBB (via the PNphpBB2 module) for Postnuke. Postnuke tended to offer the facilities we needed - although did have problems with things such as forum avatars and login sessions.
Domain name - this was easy - US domain name.COM only cost $7.95/year (with GoDaddy), or $16.95/year if using registering via proxy (to avoid having to include home address, etc).
The main point you're missing is that WAP is not specifically a document formatting system. That is just one element of WAP.
There is an interesting overview of the WAP system and the protocol stack here
WAP is a stack of protocols used for communication with mobile devices. HTTP can be carried over WAP too.
The reason I think WAP is unpopular is that it was a more advanced feature of mobile phones that people found too hard to use. The more technically oriented people who did use it have now moved on to more advanced "smartphone" supporting native HTML/HTTP and built-in full-featured TCP/IP stacks.
Actually I don't believe it is. You should be able to call a GSM phone here at the same cost as a landline.
In Australia, there are a number of GSM900/1800 networks, 2 CDMA networks and 1 UMTS (3G) network. Prepaid packs are available for about 15 USD. Prepaid packs with a cheap phone as little as 40 USD, and can be bought just about everywhere (including airports).
Get out of the US and go visit Japan, UK, Australia, etc and get a clue. Why was this modded Insightful anyway?
Obviously people want phones like this. The manufacturers are not telling people what they want - they are responding to what people want. In general, people are quite open to new technology. You just have to accept the fact the USA is the minority in the world mobile market and always has been, always will be.
Even the oldest of GSM phones have fairly complex multitasking operating systems behind the scenes, even if it is not as apparent to the end user.
If you want a phone to make calls - keep your current one that you are happy with. It's not going to stop working anytime soon.
PAL (region 4) capable players here in Australia can drive 576i.
I can easily tell the difference when connecting DVD player via SVIDEO and playing an anamorphic DVD (since with SVIDEO the DVD-player added black bars are wasting resolution), but when playing with my notebook PC connected via VGA the true native resolution of the DVD (576 * 576*16/9) shows, and already it looks substantially better.
I then compare that to 1080i HDTV which is the HDTV format used in Australia and that blows it away again.
Australian sentences generally seem to be fairly short, from what I've seen (in the state of Victoria).
For example, it seems the public is content with a violent murderer going away for 15-20 years, whereas in the US you'd probably want life, or death.
I was actually surprised at this guy for getting almost 7 years - although this is another state (WA) so I'm not too familiar with their sentencing - it will obviously differ state to state as it does in the US.
He's definitely not in Europe. There's only 1 place he could possibly be with an attitude like that, and mobile phones that are 10 years behind the rest of the world.
There have been DVB-T PC receivers for a while now, and recently cards have been shipping with HDTV support. I recently reviewed one of the first to hit Australia (since that is one of the VERY few countries outside the US that broadcasts digital HDTV).
I couldn't care less about the Australian TV content restrictions. If it means less bloody backyard/renovation shows, than so be it. Let's face it - that's all Australia can afford to put on TV anyway.
You must be in the USA. Voice quality on phones is not a problem anywhere else. If you survey any mobile user in Australia, or the UK, or Asia 99.99999% of them will say there is nothing wrong with the voice quality.
Wow - normally these types of comments appear instantly on slashdot whenever a new phone is reviewed. Today it took a while.
There is always someone who goes "Well, since this feature is of no use to me, therefore it is not needed", and surprisingly, gets modded up to +5.
The truth is, outside the US, the phone-culture is very much different. We already have phones that have long-lasting batteries, good call quality and messaging. In fact, we've had all this for at least 5 years. So phone makers have to come up with new features in order to turn a profit (believe it or not). Whilst for some unknown reason newer phones don't appeal to US customers they do in places like the UK, Asia and Australia.
Slashdot Mirror
I use my VisionPlus DVB-T card for Digital SDTV and HDTV combined with the TSReader software and the free software VLC.
Streaming is done (by default) over RTP/UDP over IPv4 or IPv6 unicast or multicast.
The problem is, with 802.11g, it does not seem to be able to reliably deliver an SDTV signal (~7mbps here in Australia) let alone a HDTV signal (~14mbps). SDTV works sometimes, however can start to break up after a while, and I have to return to 100/1000 Ethernet.
Digital TV in Australia isn't worth bothering about
You certainly share my thoughts in some respect - although most content is at least 16x9 SD, in the cities at least, the digital signal does show up a lot of poorer editing processes and artifacts during the production process.
On the other hand, in Melbourne and Brisbane we have 1080i HD (@1920x1080) and that looks absolutely stunning on some programs, and movies.
The 'orthogonal' component is referring to the spreading codes used in the multiplexing component. It means the spreading codes have zero cross-correlation. This form of CDMA has essentially two components - the actual mapping of bits to symbols (i.e. QAM, QPSK, etc) and then increasing the bandwidth of a signal, summing it with all other channels originating from the same device (i.e. control channels, voice channels, etc), and then scrambling it.
,1 -1} ...}
The actual baseband carrier is 'spun' in both amplitude and phase (and thus indirectly by the laws of frequencies, frequency) by the multiplication of the complex number. In the case of QAM-16 for example, a constellation of 16 points in the complex plane will correspond to each possible 16 values of 4 bits. When those bits are sent to the transmitter, it looks up those bits in the constellation, which corresponds to some complex number a+bj (which conseqently spins the phase of the carrier by arctan(b/a) radians, and multiplies the amplitude by sqrt(a^2+b^2).
At this point the 'modulation' effectively ends and the 'multiplexing' takes over. However, the multiplexing is quite closely integrated with the modulation process.
It's important to remember that in a CDMA system, the complex symbols are not modulated directly to the carrier. In the case of UMTS for example, they are first spread into a series of complex chips by a real-valued spreading sequence they might looks something like
{ {-1, 1, 1, -1} {1, 1
for a spreading factor of 4 (which maps each symbol into a sequence of 4 chips).
Then the chips are scrambled by a complex-valued scrambling code which is typically generated by some PN-derived sequence such as a Gold code. The scrambling code does not increase the bandwidth of the signal, unlike the spreading code.
I believe you are confusing the Nyquist Theorem with Shannon's Law.
Shannon's Law states the maximum error free digital bandwidth b bits/s of an a slice of spectrum c Hz wide is:
b = c.log2(1+s)
Where s is the signal-to-noise ratio. Thus, in this case, where b=300000000 and c=100000000 s = 7, or 8.5dB, not an unrealistic expectation.
Of course, no current form of error correction coding approaches the ideal Shannon's Law, however reasonably recently developed Turbo Codes have come reasonably close.
The sort of modulation/multiplexing technique they would be using is a Wideband CDMA technique, similar to that used by UMTS and CDMA2000 wideband technologies.
Putting it simply, the bits are mapped onto a constellation in the complex plane which rotates and changes the amplitude of the carrier. The signal is spread using 2 codes - an Orthogonal code which has poor autocorrelation properties (but ideal cross-correlation properties across codes - hence the orthogonal term), and finally a PN sequence which has excellent autocorrelation properties.
I'm not too familiar with this technology, but I can make some guesses how they might have gained speed improvements over UMTS would be:
- Very wideband - 100MHz vs 5MHz
- More precise QAM (Quadrature Amplitude Modulation) - UMTS allows upto QPSK (2 bits per symbol) or QAM-16 (4 bits per symbol). Perhaps this technology has extended this QAM-64 (6 bits per symbol).
It's a shame it looks to be analog only. Especially with the amount of Widescreen Digital and High definition content being broadcast in areas of Australia.
These were the questions I asked. I intended to setup a website for Australian mobile phone users - since no such website really existed.
.COM only cost $7.95/year (with GoDaddy), or $16.95/year if using registering via proxy (to avoid having to include home address, etc).
We spent several weeks researching hosts and experimenting with content management systems. This is what we ended up with:
Hosting - Shared hosting at Hostony.net. For around US$8/month, we got 1000M of space and around 35G of bandwidth, as well as the services we needed - such as MySQL databases, SSH, FTP, etc.
Choosing hosting was difficult - as not everyone offered all the features we needed - common problems were limitations on SQL databases, small space quotas, as well as setup fees when only on short term bill (we wanted preferably monthly payments so we could pull out whenever we needed if necessary. In the end we settled on 3 monthly payments).
Unfortunately the hosting service was unreliable - with many server reboots, timeouts, and complete outages. After complaining we were moved to a better server, which has delivered better performance (but still not up to scratch).
Content Management - we chose Postnuke and PhpBB (via the PNphpBB2 module) for Postnuke. Postnuke tended to offer the facilities we needed - although did have problems with things such as forum avatars and login sessions.
Domain name - this was easy - US domain name
The result : http://www.ausmobile.com
My advice? Don't spend up big, as the project may fail, and you will lose money.
The main point you're missing is that WAP is not specifically a document formatting system. That is just one element of WAP.
There is an interesting overview of the WAP system and the protocol stack here
WAP is a stack of protocols used for communication with mobile devices. HTTP can be carried over WAP too.
The reason I think WAP is unpopular is that it was a more advanced feature of mobile phones that people found too hard to use. The more technically oriented people who did use it have now moved on to more advanced "smartphone" supporting native HTML/HTTP and built-in full-featured TCP/IP stacks.
http://www.zdnet.com.au/news/software/0,2000061733 ,39116114,00.htm
Actually I don't believe it is. You should be able to call a GSM phone here at the same cost as a landline.
In Australia, there are a number of GSM900/1800 networks, 2 CDMA networks and 1 UMTS (3G) network. Prepaid packs are available for about 15 USD. Prepaid packs with a cheap phone as little as 40 USD, and can be bought just about everywhere (including airports).
That's because ^ is the XOR operator, not the power operator.
So effectively you are doing 2 XOR 3 - 1 = 1 - 1 = 0
I think it does.
1st January 2001 - Official start of Wide Screen Digital broadcasts in Australia
1st July 2003 - Official start of High Definition TV minimum quotas (20 hours a week)
I say these moments are definitely milestones in TV history.
*sighs*
Get out of the US and go visit Japan, UK, Australia, etc and get a clue. Why was this modded Insightful anyway?
Obviously people want phones like this. The manufacturers are not telling people what they want - they are responding to what people want. In general, people are quite open to new technology. You just have to accept the fact the USA is the minority in the world mobile market and always has been, always will be.
Even the oldest of GSM phones have fairly complex multitasking operating systems behind the scenes, even if it is not as apparent to the end user.
If you want a phone to make calls - keep your current one that you are happy with. It's not going to stop working anytime soon.
PAL (region 4) capable players here in Australia can drive 576i.
I can easily tell the difference when connecting DVD player via SVIDEO and playing an anamorphic DVD (since with SVIDEO the DVD-player added black bars are wasting resolution), but when playing with my notebook PC connected via VGA the true native resolution of the DVD (576 * 576*16/9) shows, and already it looks substantially better.
I then compare that to 1080i HDTV which is the HDTV format used in Australia and that blows it away again.
What about the swapfile though? Portions of memory containing the material could still be written out to disk.
Australian sentences generally seem to be fairly short, from what I've seen (in the state of Victoria).
For example, it seems the public is content with a violent murderer going away for 15-20 years, whereas in the US you'd probably want life, or death.
I was actually surprised at this guy for getting almost 7 years - although this is another state (WA) so I'm not too familiar with their sentencing - it will obviously differ state to state as it does in the US.
He's definitely not in Europe. There's only 1 place he could possibly be with an attitude like that, and mobile phones that are 10 years behind the rest of the world.
Sorry, forgot to include the URL:
8 91 19
http://www.overclockers.com.au/article.php?id=1
There have been DVB-T PC receivers for a while now, and recently cards have been shipping with HDTV support. I recently reviewed one of the first to hit Australia (since that is one of the VERY few countries outside the US that broadcasts digital HDTV).
Agreed. I'm an Australian, and this was the funniest thing I've read this month.
I couldn't care less about the Australian TV content restrictions. If it means less bloody backyard/renovation shows, than so be it. Let's face it - that's all Australia can afford to put on TV anyway.
You must be in the USA. Voice quality on phones is not a problem anywhere else. If you survey any mobile user in Australia, or the UK, or Asia 99.99999% of them will say there is nothing wrong with the voice quality.
Just the USA, as usual.
Please.. get off your high horse.
What model of phone is it?
Wow - normally these types of comments appear instantly on slashdot whenever a new phone is reviewed. Today it took a while.
There is always someone who goes "Well, since this feature is of no use to me, therefore it is not needed", and surprisingly, gets modded up to +5.
The truth is, outside the US, the phone-culture is very much different. We already have phones that have long-lasting batteries, good call quality and messaging. In fact, we've had all this for at least 5 years. So phone makers have to come up with new features in order to turn a profit (believe it or not). Whilst for some unknown reason newer phones don't appeal to US customers they do in places like the UK, Asia and Australia.
Fortunately you won't even have to do that - with GSM phones - there is no such thing as static :)
The cost of data is capped at A$99 per month - i.e. an all-you-can-eat service.
This is about US$60.