For the FM version of HD, broadcasters have 96Kb/s to play with. Most broadcasters are doing what is called in the trade as "multicasting". In other words they are taking the 96Kb/s stream and running two or more stereo channels on it. Many broadcast groups are doing 48Kb/s each. A number of NPR stations are running 64Kb/s as a simulcast of the analog carrier and using 32Kb/s for an alternitive feed. Needless to say, 44Kb/s stereo sounds pretty bad.
A 200 watt DC server uses the same power as an AC. The argument is how many conversions must one go through before the power is used.
In an DC plant, you will have a AC to DC power supply deliverying power to a bunch of batteries. The batteries will deliver (with the supply) typically -48 VDC to the servers. The servers then need to convert this 48 volts to DC that it wants (ie. +/- 12 and +5v). There are several conversions steps here. The AC to DC of the rectifiers; possibly the electo-chemical conversion from DC to battery and then battery to DC; and the DC to DC conversion in the server. Non of these steps are 100 % efficient.
In an AC plant you may or may not have a UPS. I will include the UPS in this flow...
AC to the UPS that gets converted to DC (battery electro-chemical conversion may be involved) and then conversion from DC to AC to be delivered to the server. The server will convert AC to the various DC voltages needed.
Again, many conversions and all not 100 percent efficient.
At our company (UnitedLayer) we have found that is is about break even.
DAB/HDradio/IBOC/Ibiquity what ever you want to call it is not CD quality. It is a very poor codec that is limited to 96Kb/s. Some stations will only be using 64Kb/s. In fact Ibiquity had to shotgun the current coded to move to another as the current one sounded so bad.
Second, you can copy music now and stamp the resulting MP3 files with meta data from RDBS. There is no difference from what is going on right now with analog radio and what will be happening with DAB. In many cases, the audio will sound better from the analog broadcast.
I like a random shuffle too as it will bring up cuts that I may not have heard for some time. The problem with a random shuffle is you can get burned out on artists and songs depending on the pool of cuts to pick from. To that, I wrote a script (playmp3s.pl) that will do a random pick of a playlist and will then look and see if it played that artist or cut name in the recent past. This smooths out the "burn out" considerably. You can see the script at:
The 75th anniversary of Philo T. Farnsworth's first demonstration of electronic television is this Saturday, September 7th.
There will be a commemoration of the event starting at 10:00AM on that day at 202 Green Street, San Francisco, the actual site of the Farnsworth laboratory on that fateful day.
Too bad FCC rules state 2.4 GHz SS equipment is limited to a maximum range of 5 miles,
No where in Part 15 is this defined.
1 watt power output and 36 dBm (4 watts ) effective radiated power.
This is defined for point-to-multipoint. Point to point you can do 20 miles. In fact we are doing this on a 22 mile link across the San Francisco Bay with 1/4 watt amps and 24 dBi antennas. Legal under Part 15.247.
He is allowed any gain of antenna he wants. He just has to back off on his transmitter power (1W and down) depending if his antenna has more than 6 dBi of gain and if he is running point-to-point or point-to-multipoint.
This is a myth. The reason microwave ovens are on this frequency is it is the band that the FCC had for "junk" devices. In fact, the original "radar ranges" that operated on train actually operated at lower frequencies.
If you go to my "bio" page you find this starry eyed paragraph...
"One of my main "themes" in life is to give tools to the
world that help them express their ideas. I have this rather
utopian idea that if everyone has the tools to exchange
ideas then the world will be a better place."
I think we all have simular ideas on this subject but this author
thinks the opposite. In this article in the NYT, he makes an
argument, although not that deeply researched, that this "global
satellite TV and Internet access have actually made the world a
less understanding, less tolerant place" as it seems lack of context
and an American centric media is the root of it. His examples are
mainly the commercial media outlets (ie. CNN) and don't cover the
Internet.
Unfortunately that is how the popular press works. They trying to
gather "eyeballs" for advertisers. Where are the most eyeballs for
their advertisers? It ain't Kabul. Keep in mind that CNN also is
influenced and fed by the US government for some of their programming.
This article makes an indirect argument for helping alternative
media outlets that do provide news with more context and is less
United States centric. Keep that in mind in choosing your news
outlet as you may be helping to reduce world intolerance.
Oh really? Try to come up with this data as required by the proposal for the RIAA if you stream...
A) The name of the service B) The channel of the program (AM/FM stations use station id) C) The type of program (Archived/Looped/Live) D) Date of Transmission E) Time of Transmission F) Time zone of origination of Transmission G) Numeric designation of the place of the sound recording within the program H) Duration of transmission (to nearest second) I) Sound Recording Title J) The ISRC code of the recording K) The release year of the album per copyright notice and in the case of compilation albums, the release year of the album and copyright date of the track L) Featured recording artist M) Retail album title N) The recording Label O) The UPC code of the retail album P) The catalog number Q) The copyright owner information R) The musical genre of the channel or program (station format)
And a listener's log listing:
1) The name of the service or entity 2) The channel or program 3) the date and time that the user logged in (the user's timezone) 4) the date and time that the user logged out (the user's timezone) 5) The time zone where the signal was received (user) 6) Unique User identifier 7) The country in which the user received the transmissions
Perhaps this is easier if you have all your music on a hard drive, but if you are a station that is a bit more electic than your average top 40 station you won't be able to create this log. This is ignoring the privacy issue of the listener log.
Not true as it has held up in court that you can destroy documents as a matter of course of doing business and not destroying documents that are about to be or are involved in a legal proceeding.
Companies and individuals destroy documents for a number of legal reasons. Such as keep the competition from seeing trade secrets, draft
copies that are not ready for public release and to minimize discovery costs.
Many companies have document retention policies right now. Most paperwork can be destroyed at any time. Some paperwork may be required by federal, state or local law to be kept. For instance, companies that are regulated by the feds have certain paperwork that they need to keep around such as banks, airlines and radio stations. Some of these document retention systems will give you the ability to differentiate between the document you are creating and how long it is to stick around.
The issue that there are holes in the system have been well known for years. All of these systems are designed so that their use was assumed to
be between "friendly" parties. Such as within a corporate environment. This is the case with snail mail, or any form of hard copy paperwork.
The problem was, how does one create a system to help with document retention policies that a company creates? Up until companies like Omniva, there wasn't a software process to handle electronic documents where you can say "I don't have that document as it has been destroyed through our retention process".
BTW... These products are not just for large companies like Microsoft. Individuals can benefit through it. Email to your tax accountant would be examples of mail that you may want to disappear after you file your returns. A number of great example on how folks have gotten screwed by electronic documents can be found in Jeffrey Rosen's book, "The Unwanted Gaze : The Destruction of Privacy in America".
There are plenty of factors that you have to deal with for long distance microwave path design. We do this kind of work. I would be happy to help non-profits and co-ops interested in looking into this solution. You can drop me a note at pozar@lns.com or call at 415-665-3790.
I would also ask folks to check out the Bay Area Wireless Users Group (http://www.bawug.org) mailing list archives for help as many folks on that list are doing long distnce 802.11 paths there and I am sure many of these guys will help you out.
Snippet of a filter for either a BGP ACL or just a route ACL... -- ! Deny martian routes ! ! 0/anything access-list 100 deny ip host 0.0.0.0 any ! 127/8 & longer access-list 100 deny ip 127.0.0.0 0.255.255.255 255.0.0.0 0.255.255.255 ! The private use nets access-list 100 deny ip 10.0.0.0 0.255.255.255 255.0.0.0 0.255.255.255 access-list 100 deny ip 172.16.0.0 0.15.255.255 255.240.0.0 0.15.255.255 access-list 100 deny ip 192.168.0.0 0.0.255.255 255.255.0.0 0.0.255.255 ! Test net access-list 100 deny ip 192.0.2.0 0.0.0.255 255.255.255.0 0.0.0.255 ! 1st and last classical B and C nets (guard nets). access-list 100 deny ip 128.0.0.0 0.0.255.255 255.255.0.0 0.0.255.255 access-list 100 deny ip 191.255.0.0 0.0.255.255 255.255.0.0 0.0.255.255 access-list 100 deny ip 192.0.0.0 0.0.0.255 255.255.255.0 0.0.0.255 access-list 100 deny ip 223.255.255.0 0.0.0.255 255.255.255.0 0.0.0.255 ! All multicast routes - the router now does this itself, but it didn't ! at one point..... access-list 100 deny ip 224.0.0.0 31.255.255.255 224.0.0.0 31.255.255.255 ! Block all routes with a mask longer than/24, access-list 100 deny ip any 255.255.255.128 0.0.0.127 --
Although this doesn't take care of a number of DDOS attacks as they come from real machines.
Storage Tek TimberWolf 9710 to be exact. I was the operations person at Alexa/Internet Archive from '96 until '98. This is why the USENET archive stopped in '98 too. No one there to handle it and if you know about running a newserver, many don't want to handle one. Tim Pozar/Ex-Director of Operations
How can this be a good thing when subscribers to ORBS are now blocking anyone sending mail from AOL using non-AOL mailers? If I was using AOL I certainly would something else like Netscape, or Eudora.
Why don't they just fix their MTAs with filtering software such as Brightmail? Also, I thought they had some gee-wiz internal anti-spam technology that is 'spota work. Sheesh.
Slashdot Mirror
For the FM version of HD, broadcasters have 96Kb/s to play with. Most broadcasters are doing what is called in the trade as "multicasting". In other words they are taking the 96Kb/s stream and running two or more stereo channels on it. Many broadcast groups are doing 48Kb/s each. A number of NPR stations are running 64Kb/s as a simulcast of the analog carrier and using 32Kb/s for an alternitive feed. Needless to say, 44Kb/s stereo sounds pretty bad.
Tim
A 200 watt DC server uses the same power as an AC. The argument is how many conversions must one go through before the power is used.
In an DC plant, you will have a AC to DC power supply deliverying power to a bunch of batteries. The batteries will deliver (with the supply) typically -48 VDC to the servers. The servers then need to convert this 48 volts to DC that it wants (ie. +/- 12 and +5v). There are several conversions steps here. The AC to DC of the rectifiers; possibly the electo-chemical conversion from DC to battery and then battery to DC; and the DC to DC conversion in the server. Non of these steps are 100 % efficient.
In an AC plant you may or may not have a UPS. I will include the UPS in this flow...
AC to the UPS that gets converted to DC (battery electro-chemical conversion may be involved) and then conversion from DC to AC to be delivered to the server. The server will convert AC to the various DC voltages needed.
Again, many conversions and all not 100 percent efficient.
At our company (UnitedLayer) we have found that is is about break even.
Tim
Anyone with a cordless phone can wipe it out.
Tomita used a Tarbell cassette interface card to encode data on his records back in the late seventies.
DAB/HDradio/IBOC/Ibiquity what ever you want to call it is not CD quality. It is a very poor codec that is limited to 96Kb/s. Some stations will only be using 64Kb/s. In fact Ibiquity had to shotgun the current coded to move to another as the current one sounded so bad.
Second, you can copy music now and stamp the resulting MP3 files with meta data from RDBS. There is no difference from what is going on right now with analog radio and what will be happening with DAB. In many cases, the audio will sound better from the analog broadcast.
Tim
http://www.lns.com/papers/playmp3s/
is disconnected now. Bummer.
http://www.barwn.org
The 75th anniversary of Philo T. Farnsworth's first demonstration of electronic television is this Saturday, September 7th.
There will be a commemoration of the event starting at 10:00AM on that day at 202 Green Street, San Francisco, the actual site of the Farnsworth laboratory on that fateful day.
http://www.lns.com/papers/part15/
for a paper on this issue.
Tim
No where in Part 15 is this defined.
1 watt power output and 36 dBm (4 watts ) effective radiated power.
This is defined for point-to-multipoint. Point to point you can do 20 miles. In fact we are doing this on a 22 mile link across the San Francisco Bay with 1/4 watt amps and 24 dBi antennas. Legal under Part 15.247.
Tim
See my paper at:
http://www.lns.com/papers/part15
for details on FCC Part 15.247.
This is a myth. The reason microwave ovens are on this frequency is it is the band that the FCC had for "junk" devices. In fact, the original "radar ranges" that operated on train actually operated at lower frequencies.
http://www.lns.com/papers/part15/Regulations_Affec ting_802_11.pdf
It covers everything from co-users (interference)to Radio Frequency Radiation to human tissue, to antenna height and equipment certification.
Part 15 devices are not even on a secondary service level. They are on a non-level. They have no peering or priority over any other user.
Tim Pozar
- "One of my main "themes" in life is to give tools to the
world that help them express their ideas. I have this rather
utopian idea that if everyone has the tools to exchange
ideas then the world will be a better place."
I think we all have simular ideas on this subject but this author thinks the opposite. In this article in the NYT, he makes an argument, although not that deeply researched, that this "global satellite TV and Internet access have actually made the world a less understanding, less tolerant place" as it seems lack of context and an American centric media is the root of it. His examples are mainly the commercial media outlets (ie. CNN) and don't cover the Internet.Unfortunately that is how the popular press works. They trying to gather "eyeballs" for advertisers. Where are the most eyeballs for their advertisers? It ain't Kabul. Keep in mind that CNN also is influenced and fed by the US government for some of their programming.
This article makes an indirect argument for helping alternative media outlets that do provide news with more context and is less United States centric. Keep that in mind in choosing your news outlet as you may be helping to reduce world intolerance.
Oh really? Try to come up with this data as required by the proposal for the RIAA if you stream...
A) The name of the service
B) The channel of the program (AM/FM stations use station id)
C) The type of program (Archived/Looped/Live)
D) Date of Transmission
E) Time of Transmission
F) Time zone of origination of Transmission
G) Numeric designation of the place of the sound recording within the program
H) Duration of transmission (to nearest second)
I) Sound Recording Title
J) The ISRC code of the recording
K) The release year of the album per copyright notice and in the case of compilation albums, the release year of the album and copyright date of the track
L) Featured recording artist
M) Retail album title
N) The recording Label
O) The UPC code of the retail album
P) The catalog number
Q) The copyright owner information
R) The musical genre of the channel or program (station format)
And a listener's log listing:
1) The name of the service or entity
2) The channel or program
3) the date and time that the user logged in (the user's timezone)
4) the date and time that the user logged out (the user's timezone)
5) The time zone where the signal was received (user)
6) Unique User identifier
7) The country in which the user received the transmissions
Perhaps this is easier if you have all your music on a hard drive, but if you are a station that is a bit more electic than your average top 40 station you won't be able to create this log. This is ignoring the privacy issue of the listener log.
Companies and individuals destroy documents for a number of legal reasons. Such as keep the competition from seeing trade secrets, draft copies that are not ready for public release and to minimize discovery costs.
Many companies have document retention policies right now. Most paperwork can be destroyed at any time. Some paperwork may be required by federal, state or local law to be kept. For instance, companies that are regulated by the feds have certain paperwork that they need to keep around such as banks, airlines and radio stations. Some of these document retention systems will give you the ability to differentiate between the document you are creating and how long it is to stick around.
The problem was, how does one create a system to help with document retention policies that a company creates? Up until companies like Omniva, there wasn't a software process to handle electronic documents where you can say "I don't have that document as it has been destroyed through our retention process".
BTW... These products are not just for large companies like Microsoft. Individuals can benefit through it. Email to your tax accountant would be examples of mail that you may want to disappear after you file your returns. A number of great example on how folks have gotten screwed by electronic documents can be found in Jeffrey Rosen's book, "The Unwanted Gaze : The Destruction of Privacy in America".
Seems this edition is running on a BSD licensed OS (FreeBSD). Geee... I would think it would be a GPL box such as Linux. :-)
I would also ask folks to check out the Bay Area Wireless Users Group (http://www.bawug.org) mailing list archives for help as many folks on that list are doing long distnce 802.11 paths there and I am sure many of these guys will help you out.
Tim Pozar
Snippet of a filter for either a BGP ACL or just a route ACL... /24,
--
! Deny martian routes
!
! 0/anything
access-list 100 deny ip host 0.0.0.0 any
! 127/8 & longer
access-list 100 deny ip 127.0.0.0 0.255.255.255 255.0.0.0 0.255.255.255
! The private use nets
access-list 100 deny ip 10.0.0.0 0.255.255.255 255.0.0.0 0.255.255.255
access-list 100 deny ip 172.16.0.0 0.15.255.255 255.240.0.0 0.15.255.255
access-list 100 deny ip 192.168.0.0 0.0.255.255 255.255.0.0 0.0.255.255
! Test net
access-list 100 deny ip 192.0.2.0 0.0.0.255 255.255.255.0 0.0.0.255
! 1st and last classical B and C nets (guard nets).
access-list 100 deny ip 128.0.0.0 0.0.255.255 255.255.0.0 0.0.255.255
access-list 100 deny ip 191.255.0.0 0.0.255.255 255.255.0.0 0.0.255.255
access-list 100 deny ip 192.0.0.0 0.0.0.255 255.255.255.0 0.0.0.255
access-list 100 deny ip 223.255.255.0 0.0.0.255 255.255.255.0 0.0.0.255
! All multicast routes - the router now does this itself, but it didn't
! at one point.....
access-list 100 deny ip 224.0.0.0 31.255.255.255 224.0.0.0 31.255.255.255
! Block all routes with a mask longer than
access-list 100 deny ip any 255.255.255.128 0.0.0.127
--
Although this doesn't take care of a number of DDOS attacks as they come from real machines.
BTW... I belive the Storagetek has been off line as they are using better storage media, but Kurt is trying to revive it.
- Tim Pozar
Storage Tek TimberWolf 9710 to be exact. I was the operations person at Alexa/Internet Archive from '96 until '98. This is why the USENET archive stopped in '98 too. No one there to handle it and if you know about running a newserver, many don't want to handle one. Tim Pozar/Ex-Director of Operations
How can this be a good thing when subscribers to ORBS are now blocking anyone sending mail from AOL using non-AOL mailers? If I was using AOL I certainly would something else like Netscape, or Eudora.
Why don't they just fix their MTAs with filtering software such as Brightmail? Also, I thought they had some gee-wiz internal anti-spam technology that is 'spota work. Sheesh.