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EDIT: Thanks very much to @pjc50, @dave-tweed, and @MoJo For their valuable comments. I apologize for the ambiguity of the original question. I've made edits below to clarify.

I am in search of a wireless communication protocol purpose-built for broadcast digital communications. I've looked at Bluetooth 4.0 Connectionless L2CAP mode, and ZigBee unicast operation; neither support enough data throughput, or sufficient range.

EDIT: I have the following application in mind: A digital broadcast that could support a very dense area of receivers in about a 1km radius, for example in a stadium during a sporting event. I expect the operating environment to be extremely noisy on the 2.4GHz band; again, think a stadium during a sporting event. A central tx unit will be installed at the event. Receivers will be battery powered dongles that receive data, and transfer it to a smartphone via Bluetooth. In terms of bandwidth, I'd like to support 1 channel of streaming audio, along with asynchronous (5 seconds of delay is fine) data, probably including images. The transmitter will broadcast live audio, along with asynchronous data. More recently published data will be broadcast more frequently, and the re-broadcast frequency of previous updates will decay over time.

Requirements:

  • Supports generic data transmission
  • Resistant to interference
  • Capable of supporting transmission on arbitrary spectrum OR operates on unlicensed spectrum. EDIT: I totally understand that no one will sell me a transmitter that I can tune to the frequency of my local airport tower. I mean that it should allow operation on an unlicensed frequency, within applicable tx power restrictions.

  • Data throughput of ~2MBps possible. EDIT: Excuse the preposterousness of the previous data rate. 200 Kbps would be lovely.

  • EDIT: Additional requirement: True unidirectional, connectionless broadcast operation. I am hoping to design something that will support 1000s of simultaneous receivers.

The following would be nice to have.

  • A full stack protocol, like Bluetooth or IEEE 802.11 that handles both the physical and link layers.

  • Implemented in commercially available ICs.

I've been searching the web for a while, but all references I can find assume digital video transmission, rather than generic data.

Thanks for your attention.

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  • \$\begingroup\$ What range do you want? All the unlicensed spectrum devices have a range limitation as part of the unlicensed requirement; and "transmission on arbitary spectrum" is not going to pass FCC. \$\endgroup\$ – pjc50 Jun 9 '14 at 7:45
  • \$\begingroup\$ What exactly do you mean by "broadcast"? The word usually implies one-way communication (one transmitter, many receivers), but then you talk almost exclusively about bidirectional protocols. What are you really trying to accomplish here? \$\endgroup\$ – Dave Tweed Jun 9 '14 at 11:40
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    \$\begingroup\$ Wi-Fi does broadcasting. \$\endgroup\$ – Kaz Jun 9 '14 at 21:51
  • \$\begingroup\$ Without any more information, it's hard to make a recommendation other than Wi-Fi. Your users have smartphones anyway, so why not use it? This has the advantage of not putting your devices at risk of being pocketed at the end of the event. If you want to control the content better, make a nice little app that will automatically connect everything. I believe you could use broadcast, or possibly multicast, for this. \$\endgroup\$ – Jason_L_Bens Jun 18 '14 at 17:06
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Your requirements are quite demanding. Nordic do some 2.4GHz radios that might cope, or you could pair up a couple of them to get dual channel operation.

If you need more range the ISM bands (433, 868, 915MHz) are a good bet, but data rates are nowhere near what you want. 500kbps maximum. Again, you could have four radios on different channels perhaps.

The reason you have having trouble finding anything is that a radio capable of what you want is going to be quite a complex device, most likely with some kind of ARM processor and DSP attached. It will need to do error recovery, and even then will be expected to tolerate a certain number of bit errors per second which can be masked in video.

It would help to know more about your application.

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