How to multicast audio stream on Mobile Phones?


Please I need you to help me on this. Am going to be detailed in proposing forth my challenge, hence this post might be very lengthy, but please, I beg you to be patient in reading and understand my challenge, and please advice me on the path to follow.

I need a way to broadcast a live event on MOBILE PHONE. Yes, I know what am saying - MOBILE PHONE. I know you would want to suggest that I broadcast the live event using Internet Streaming, but in my case, it is not useful. The event that I intend to broadcast on mobile phone takes place periodically in a very large city in my country but we have a lot of potential attendants of the event at the other remote, far-end of the country. This remote end of the country is a village in Africa where there is no reach of broadband internet, hence leaving out the option of internet live stream, however, this remote village has reliable telecommunication infrastructure via mobile phone, hence, the reason why am thinking of broadcasting a live audio event on mobile phone.

Now, the challenge is that I don’t know how to go about doing this. I know much about web development, and I know a little bit of TCP/IP networking, but I have no idea of telephony technology - though I’ve just started to get myself acquainted with telephony technology and in the process, I discovered Asterisk, and that’s why am here.

From my experience in TCP/IP networking, I know that its possible to have a live audio-stream broadcast (RTP) but with the research I’ve made so far into telephony technology, it seems hard finding an equivalent on mobile phone. The best I’ve got on mobile phone that is related to live-audio broadcast is PHONE CONFERENCING (CONFERENCE BRIDGE), but this is not what I want. Why - simply because phone conferencing is a multi-party communication in which every participant consumes a dedicated voice channel on the PSTN, though most of the participants might connect to the conference bridge MUTED, but every dialled-in participant will still consume a dedicated voice channel from the perspective of the Mobile Network Provider from which they dialled-in. (Correct me if am wrong on this cause am a newbie to telephony). What I really want is something like MULTICASTING rather than UNICASTING, so that when a participant dials-in, he/she is connected as just a LISTENER, rather than as both a LISTENER & SPEAKER. Yes, I know that you might want to suggest that the conference bridge can MUTE participants as they are being connected, but still from the end of the mobile telecom provider from which the participants dialled-in, he/she is seen as consuming FULL DUPLEX (both Uplink and Downlink), even though the conference bridge muted the participant. You should by now be wondering why am concerned about how much resources is consumed on the telecom provider’s end and I’ll explain why.

I said earlier that the intended live-audio broadcast on mobile phone is targeted at people in a remote area so that they can listen to our event on phone. This event usually last for a minimum of EIGHT (8) HOURS and the projected number of people that will potentially listen to the audio broadcast on mobile phone is TEN THOUSAND (10,000)! Now, imagine the amount of resources that will be consumed at the telecom provider’s end if 10,000 subscribers are CONCURRENTLY on the phone for 8 hours, assuming that all the 10,000 participants are using the same telecom provider. Please get me right - am not saying that telecom providers don’t have the capacity to withstand lingering peak periods, but they will consequently have to charge the normal phone charges, which consequently means that the cost of listening to our event on phone by each participant, will be the total cost of making a phone call for 8 hours to a normal telephone number - and I tell you, we have calculated this amount, and it is up to 10 times the cost of transporting from the remote area down to the city where the event is held, hence listening on phone by dialling into a conference bridge in which you are billed the normal phone charges is not justified. So the aim is to implement a technology in which the cost of listening on phone will be far less than the cost of travelling down for the event. If you are reasoning along with me, your suggestion should be that I should try to negotiate a reduced billing plan with a particular telecom provider servicing the remote area. Yes, that is exactly what I was thinking about when I was looking at a technology which will consume less resources at the telecom provider’s infrastructure. If the way my technology is implemented consumes drastically reduced resources at the telco’s infrastruture, I would be able to negotiate a highly reduced billing plan for my end users (people listening to my event on phone), and hence, the total cost of making an 8 hours call to my phone system would be less than the total cost of transporting physically down to the event.

So, I guess that you should by now have a better understanding of what I need and why I assume that a conference bridge will not serve my purpose well. If you have still not yet got what my need is, let me summarize it like this - I NEED A WAY TO MULTICAST AUDO ON MOBILE PHONE, AND IF MULTICAST IS NOT POSSIBLE, AT LEAST A WAY IN WHICH MANY MOBILE USERS CAN LISTEN TO AUDIO ON THIER PHONE WITHOUT IT BEING A BOTTLENECK TO TELCO’S INFRASTRUCTURE.

From the beginning, I stated clearly that I don’t know anything about telephony but I’ve made little online research and from my research, I’m thinking in the direction of the three technologies listed below:

I already made explanation on conference bridge and how it might not be useful in solving my problem. Please correct me on this, in case you feel that there is another way I can implement a conference bridge to solve my need.

The second technology - RING BACK TONE - only exist in my head as an idea, so let me explain, so that you can suggest if its possible.

Since many mobile telco’s offer custom ringback tone service in which a custom music is played back to the calling-party while the called-party’s phone is ringing, then, it should be possible to setup my phone-system so that when my phone system is dialled, it plays back a live audio feed as a ringback tone. I have a feeling that if this is possible, then it should not consume much resources on the telecom provider’s infrastructure since a dedicated voice path is not yet established while the ringback-tone is being played to the calling-party. Note that my phone system will not pick the call, but just simply play a ringback tone to the caller. If the aforementioned is true and possible, then the challenge is this - IS IT POSSIBLE THAT AFTER NEGOTIATING WITH A TELECOM PROVIDER, THEY CAN DESIGN AN OVERRIDE IN THIER SYSTEM SO THAT WHEN MY PHONE SYSTEM IS RINGING (I.E. PLAYING THE RINGBACK TONE TO CALLERS TO MY PHONE SYSTEM), THE PROVIDER DOES NOT TEAR DOWN THE CALL IF MY PHONE SYSTEM DOES NOT PICK THE CALL FOR 8 HOURS. This is just an idea, and it might sound stupid, and if it’s really stupid, I don’t expect you to laugh at me because I already stated from the beginning that am a complete newbie to telephony technology, and by the way, that’s why am asking for your suggestion and direction.

The last technology that am still thinking about is EXPLICIT CALL TRANSFER. Yes, as I said - “still thinking about it” - not yet an idea because I really do not know what it is all about, I only stumbled upon it while making my research, so please let me know if this is a technology that will solve my problem as stated above.

Finally, I need to re-state and make the following points clear.

  1. Am a complete newbie to telephony technology, so I stand to be corrected in everything that I’ve said above.
  2. Am ready to spend the amount of money required to setup the phone system that will solve the problem above, but my major priority is ensuring that the cost of using my phone system to listen to the live event for my end users is drastically reduced.
  3. Am prepared to enter into a contract with a mobile telecom provider through which this service will be provided
  4. The country is in Africa and the remote area is a village.

Please, help me by making suggestions, advicing me on where to get further information, or giving me directions on who to contact.

Thanking you in advance for helping a newbie

This really needs to handled within the mobile phone network. Failing that, you need large numbers of landline circuits (or the equivalent from a VoIP provider.

If you try and do it directly to the mobile network, as well as being possibly more costly in terms of call charges, you will almost certainly saturate the local base station, which will both limit your number of subscribers, and possibly get you banned from the network for inappropriate use (because you will lock out all the other local callers).

The only way you are going to achieve this is by talking to the mobile phone operator. Even then, they may not have the equipment necessary to do this with any level of efficiency.

Unless they do provide a specific broadcast service, they will have to use conference bridges, but I suspect you cannot get conference bridges that handle that number of calls. Also, to use the network effectively, this really needs to be done in a distributed fashion.

The mobile phone operator also needs to be involved because of the possibility of harm to the operation of their network, due the the large number of long duration calls.

Sorry, I missed the point that this was a all directed at one village. That would probably over-saturate the cellular network in that village by two to three orders of magnitude! (On the other hand, a distributed solution isn’t needed!)

The only realistic solution would be a low power broadcast transmitter, on whatever band is used by normal portable radios in your country. You would have to talk to the relevant government authority to see what their view was about licencing such an arrangement, but the low power transmitter you would need ought to be a commodity item.

One thing to remember, if this is a musical event, is that digital mobile phone codecs are not designed to handle music well.