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Implementing a CC2520 packet sniffer which can simultaneously scan all channels

Woosuk Lee
Prodigy 160 points
Other Parts Discussed in Thread: CC2520, CC2530

Hi all,

From the CC2520 specification, it says it provides 'packet sniffing mode.'

It seems it provides a packet sniffing function for a predefined channel.

However, I'm interested in implementing a CC2520 based 802.15.4 packet sniffer which can simultaneously scan all the 16 channels.

Is it possible to implement such a packet sniffer which can simultaneously scan all the 802.15.4 channels without channel hopping?

If not, could you provide me with any possible idea?

Thank you.

 

 

 

 

  • 0
    Guru 31280 points

    Hi,

     

    This device can be programmed for listening/transmitting over one channel at a time

    (cc2520 datasheet, section 16 - Frequency and Channel Programming), so for sniffing

    several channels, physical value of register must be changed, therefore, by definition

    it can not sniff for traffic in several channels simultaneously.

    I know that you are trying to avoid the hopping thing, but some trade offs must be made eventually

    It all depends on the design and the final application.

    For example if you are intend to visualize that (sniffed) data to a human being, you can alter

    between channels "fast" enough for a human eye, so basically achieving a parallel scanning

    effect. Naive, I know, but works like a charm. :)

    In fact, TI's spectrum analyzer sample application based on that strategy.

  • 0 in reply to Igor Sherer
    Prodigy 160 points

    Thank you for the reply.

    As you mentioned, I could implement an 'all-channel packet sniffer' by altering the value of the register which defines channel number. 

    However, if fast transition among channels is the only way to scan all the channels, can we scan all the channel without missing any packets?

    There is obviously a possibility to miss packets during transition from one channel to another if the transition is not fast enough.

    Is the transition time negligibly short enough in terms of perfectness of packet reception ?

     

    I'm also curious about how the TI's spectrum analyzer is implemented.

    By the way, what do you mean by TI's spectrum analyzer?

    Do you mean the packet sniffer available from the link below?

     

    http://www.ti.com/tool/packet-sniffer&DCMP=MSP430&HQS=Other+OT+smartrfsniffer

     

     

    Thank you.

     

     

  • 0 in reply to Woosuk Lee
    Guru 31280 points

    Hi,

     

    Woosuk Lee said:
    can we scan all the channel without missing any packets?

    Usually I would say no, but "usually" means that I aware of the application, here on the other hand

    I'm not sure what is the right answer, since I'm completely unaware of the application. I know that it

    should be some sort of packet sniffer, however, what is the period between two sequential packets

    on a single channel, is this period deterministic or stochastic, etc..?

     

    Woosuk Lee said:
    transition time negligibly short enough in terms of perfectness of packet reception

    I don't know exactly, I have no the information to answer this question properly. You should be investigating

    the datasheet in more detailed way, maybe to search the community for an answer.

     

    Woosuk Lee said:
    By the way, what do you mean by TI's spectrum analyzer?

    There are some SW examples for cc2530 device. Here's a link to the download,

    read the documentation first (inside the zip).