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How to use TI 2.4GHz chipset to make voice call like walkie-talkie

wells
Intellectual 460 points

Dear expert,

Our company want to use 2.4GHz chipset to make voice call like walkie-talkie. The idea is that we will design a hand-held device with 2.4GHz chipset. The RF output power is Class one. So a team member with this device can communicate in about 100 meter range. The voice communication should be broadcast voice. If the team has ten devices, one make call with the device, the other nine devices can listen to the voice at the same time.

As we know, the Bluetooth is designed for point to point voice transfer. Is it possible to make any changes to realize point to multi points voice tranfer? Or do you have any proposal to realize our idea? Thank you!

Best Regards,

Wells

  • 0
    TI__Mastermind 36395 points
    wells,

    This is not straight forward. Walkie-talkies are analog FM devices these devices are digital in nature.

    Some time ago we released an appnote on streaming data from various nodes. This software does 1 to 1 in the presence of many others, but you could change this to do 1 to 10. Just to warn you, it is not a solution, there is some work that needs to happen between this appnote and a product.

    www.ti.com/.../litabsmultiplefilelist.tsp

    Regards,
    /TA
  • 0 in reply to TA12012
    Intellectual 460 points
    Hi,

    Thank you very much.
    We have an idea. But we don't know whether it is feasible. Please give us some advice.

    A group have ten BT devices, named #1~#10. Device #1 is the manager. Device #1 will pair with device#2~#10 one by one, and tell them the key, sync time, hopping frequency sequence and etc. After that, Device #1 ~#10 will receive the signal in the air with the same hopping frequency sequence. So if any device make a voice, the other nine devices can receive the voice.

    Best Regards,
    Wells.
  • 0 in reply to wells
    TI__Mastermind 36395 points
    Wells,

    No, this is not how Bluetooth is designed.

    Regards,
    /TA
  • 0 in reply to TA12012
    Intellectual 460 points
    Hi,

    I do know that is not how Bluetooth is designed. But we don't want to design a standard BT device. We want to modify the software of BT solution to design a special wireless device. Does TI have this kind of BT solution that has open source code to modify the protocol and even the low-level operation of BT chipset?

    Best Regards,
    Wells
  • 0 in reply to wells
    Intellectual 675 points
    Hello Wells,

    You don't need Bluetooth. All you need is a point to point protocol that can make broadcast and multicast.
    I suggest you to develop your own protocol using IEEE 802.15.4. There are several 2.4GHz chipsets that could be used.
    I don't know how fast your packets should be sent in order to achieve an uninterrupted real-time conversation.

    Keep in mind that Zigbee and Bluetooth are protocols built over IEEE 802.15.4 standard.
  • 0 in reply to Alessandro Soncini
    Intellectual 460 points
    Hi Alessandro Soncini ,

    You are right. We developed samples similair with your idea. We found there are some disadvantages:
    (1) Based on the IEEE 802.15.4 chipset on the market, frequency hopping is not possible.
    (2) Based on the IEEE 802.15.4 chipset on the market, there is no strong voice encode and decode processor embeded. If we add an extra DSP or vocode processor, the size and power consumption of the total solution is much bigger than bluetooth.

    So in order to resolve the above problems, we want to re-use the hardware of bluetooth chipset and modify the software and protocol of bluetooth. But there is no such bluetooth solution that has open interface to user. Maybe the only way is buying the bluetooth ip core, modifying, and producing own wireless cihpset.

    Best Regards,
    Wells
  • 0 in reply to wells
    Intellectual 675 points
    Hello Wells,

    I don't know how you can manage point-to-multipoint synchronization for frequency hopping without a topology with link or at least pairing.
    Does your current chipset already do the voice encode/decode and has Bluetooth transmission?
    Which kind of architecture your chipset uses? Is it a SoC? DSP? 8, 16 or 32 bits? What is the clock frequency?

    I've seen some ARM based chipsets that I think they could suit your application, but again, I don't know nothing about voice applications.
    I may be talking nonsenses here, but I'm just trying to help.
  • 0 in reply to Alessandro Soncini
    Intellectual 460 points
    Hi Alessandro Soncini ,

    Thanks for your kind help.

    The topology with link or pairing is required for point-to-multipoint synchronization for frequency hopping. But there is no such a solution that has open interface to let user to control the software of link level.

    In our samples, we used a TI DSP and a 802.15.4 transceiver. The DSP is used for the voice encode/decode. But the size and consumption is not satisfied for portable products. So we plan to give up this solution.

    Best regards,
    Wells