Hi everybody,
Hi everybody,
When we talk about unlicenced broadcasting in a “large” term, we can include many others distributions system and techonology, not only am or fm bands. I think about wifi and particularly whites spaces or “super wifi”. In the US the Fcc as aprroved the use of this technology for unlicenced operation.Here in Canada, Industry Canada is following the fcc for the same application. Somes years will needed, to see some kind of devices on the market, but the large public will beneficiate of this technology in a near futur. You can read a paper below about this subject and you can imagine all possibles applications, and streaming radio broadcast directly to a community.
This is the link:
Now imagine the futur 🙂
Fred
From the Choir
Yes, Fred Parent, you are correct about the great potential of the coming white spaces for “low power” broadcast application. You are speaking to the correct website with this message, very much “speaking to the choir, as they say.
In a real sense Part 15 low power radio amounts to “white space pioneering,” as we have been using what could easily be called “the nation’s first white spaces,” consisting of unused radio channels, for our activity.
The informative link you provided kind of made this point, that because so many of us will be using these new avenues, the available audience becomes highly diluted. We already notice that with the infinity of web choices in video, audio and other pastimes, the audience may already be soaked up.
But that isn’t stopping us.
internet is a communication
internet is a communication network, but the content can take different way to destination on different device. The kind of device determine the kind of audience market. A web radio on a PC and a internet wifi radio can be the same streaming flux but not the same “medium” and not necessarely the “same kind” of peoples listen too. This reality can be apply for TV. You watch the tv for entertainment et you stay seat on your rocking chair when you watch the tv. But when you watch video online, you have more interactive control…The différence is the device and habits associates to.
But one thing is for sure, when you control the medium, you control the message. Also, when you have a on air service, licenced or unlicenced, you have a advantage on a simple webradio for exemple, because you control the “medium” and anybody can pickup your signal and find you by chance. Any peoples can open a online radio station but only passionates and knowledgeable peoples can start up a city wide wireless network. A ISP can provide internet on this kind of network or not and provide content on a exclusive streaming application on this network. You have the advantage because you control the service and one advantage of unlicenced service, you have less regulation restrictions about content and practice. So yes, internet is a very competitive content network but, you can reach audience of many kinds of way when using wifi airwaves and you “out of the herd” if you take this way.
**A other important point is the best is your content, the best will be your audience whatever is your mode of transmission;)
Fred
Vulnerable
The only drawback to the net and wi-fi systems is that they are subject to the “One Button Wonder” that will soon be tested this fall by the White House.
And when big corporate interests lobby in the chambers and hallways of Washington DC, that tends to make things a bit more complicated….and since many others follow the footsteps of the US…well that pretty much puts the nail in the coffin.
It won’t be as simple as stringing up wi-fi units all over town…count on it.
RFB
You don’t need to wait for
You don’t need to wait for this technology (which may or may not show up in a useable or inexpensive form) to do this kind of thing today.
Both the FCC and Industry Canada allow up to 1 watt of power and a 6db gain antenna for unlicensed 2.4 Ghz Wireless networking. You can actually use more power for point to point applications with high gain antennas. So forget about the Internet – you can set up your own, private or open, Intranet, and use streaming technology to broadcast RIGHT NOW. Any device with WiFi capabilities would be able to connect to your Intranet and receive your stream – SmartPhones, Internet radios, computers.
Although still not common, you can purchase Internet radios in portable radio form factors – the new portable transistor radio! You would need to find one that can be programmed, and not just rely on the Internet to get stream addresses (you’re probably not going to want to allow devices connecting to your hotspot to access the Internet).
I’ve been playing around a bit with networking technology – it’s hard to find the time – but 1 watt amplifiers are commonly available (although I’ve not had any experience with the latest, cheap stuff from China), as are gain omnidirectional antennas from companies such as Cushcraft.
So, why wait?
somes technicals precisions about wifi
Don’t forget, wifi is a “two ways” communication”. So the receiver is also transmitter. So, if you have un “big monster acces point” like 1 watt with a large mouth, but littles ears, the receiver device can’t talk back to the AP to negociate the protocole. 1 watt= 30dbm and 1 watt into a 6dbi antenna=36 dbi.It’s right with the regulations.
But don’t mistake about dbm and dbi. The total radiated power authorized in canada and usa for the 2,4Ghz band is 4 watts. You can calculate the total dbi like this with a table conversion dbm/watt:
exemple
16dbm=40 mw
if you have a 20 dbi sector antenna you have a total of 36 dbi, you’re ok with the law. However to complie with the rules you must have a complete device certified under rss 210 for canada and part15 for US(radio and antenna sold together) Wifi amplifier is not a good idea if you want only reache low power devices on the client side, because amplifier are often noisy. Because the reception is also important in wifi communication, you must have a hight sensitive AP. On a conventional acces point you can get -97db in reception with 1 mbps datarate and only -75 with 54mbps. More is your data rate less is your range.
It is preferable to use less power applied to the antenna at the Access point and use more powered antenna gain to reache fars devices. A 802.11b Access point with 1mbps data rate and 90 degres sector antenna on a 40feets tower and a clear line of sight can range 600 to 800 meters on a simple laptop with lowbit rate streaming and multicast mode. If you put up the datarate to 54mbps you can only go 200 or 250 meters from the Access. The multicast mode allow all clients to see the content in same time. You must use a udp protocole for this. The outcome is less bandwith is used and more clients can connect to the AP.
Some companies supply low cost outdoor access point whit hi gain antenna.The best to cover a large area in a same location, is use 3 hight gain sector antennas to cover a 360 degres radius, the same techonology of cell phone.
stay tune on your ipod 😉
Fred
Other Considerations
It is all well in good, but the most important thing to keep in mind is that the band is shared with other wi-fi devices and other electronics that use the 2.4Ghz band.
I think its a good idea generally.
RFB
it’s true
Yes the big challenge is the interference from other 2.4ghz devices like cordless phone, microwave oven, etc etc…
Some “smart” acces points can deal with the interferences in real time channel analyzing and beam forming technology. but you must pay the price. If you are in rural environnement like me the interference and obstruction is not a big probleme;)
If you/re streaming radio
If you/re streaming radio broadcasts, I don’t think that speed is a huge problem. For example, Artisan Radio’s stream is 40Kbps/second mono, and it sounds good (FM broadcast quality) down to 32Kbps. Even my Internet connection upload speed is at most 2 Mbps (recently upgraded from 1Mbps). And you can support up to 50 users at that 2 Mbps speed (unicast), more if you reduce the stream speed (I’ve never been able to figure out the steps to multicast, I would imagine that you would need a router/access point that supported it). So I would be perfectly happy to get that speed (1 Mbps) for, say, a range of approximately 1 km.
I’m currently experimenting with this technology right now. I don’t know how you calculated those ranges, but I’ve also found that experimentation gives you the real values (either lower or higher).
And as I stated previously, the advantage is that it’s here right now.
1 km is possible
Hi ArtisanRadio,
Yes 1 km is possible at 1mbps. My estimations of the range are “conservatives” but you can reach clients in the “VERY BEST” conditions and outdoor environnement at this distance. But The problem to estimated the wifi range is the hight frequency. The 2.4Ghz band is less predictable that fm for exemple. Two guys can have the same system with the same antenna and output power but one can make 100 meters and the other 1km. Also the client device is the key of a good range. Laptops have generaly more gain compared to ipod or iphone on this band because the inside antenna on this devices is more powerful. Also, a client can have a usb wifi card with 9dbi rubber duck antenna and pick up your signal 3km aroud with no problem. The difference with the super wifi will be the important potential of one access point will be probably the same coverage of 4 or 5 2,4Ghz access point. This is the interesting way for this technology but yes we can work right now with good traditionnal wifi gear for several years 😉
have fun with wifi experimentation,
Fred