+ Post New Thread
Results 1 to 9 of 9
  1. #1
    Advanced Member level 1
    Points: 3,240, Level: 13

    Join Date
    May 2013
    Posts
    424
    Helped
    82 / 82
    Points
    3,240
    Level
    13

    Star topology chipset for long range (high power) comms

    Hi everyone,

    For a project involving multiple drones communicating to a single base station, I'm looking for a chipset (or alternatively a module) that supports a star topology network (i.e. multiple transmitters sending data to a single receiver). I need quite a bit of range (about > 2 km) with antennas that aren't ridiculously large since they need to be mounted on drones. For throughput I'm looking for about 100 kb/s.

    I'm flexible regarding frequency and transmission power, as long as it's in an ISM band.

    It's the first time I'll be designing something like this, so any tips and suggestions are much appreciated!

    Many thanks,

    AC

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 1
    Points: 3,240, Level: 13

    Join Date
    May 2013
    Posts
    424
    Helped
    82 / 82
    Points
    3,240
    Level
    13

    Re: Star topology chipset for long range (high power) comms

    As it can help others, I've settled for the combination of a Nordic Semi nRF905 front-end chip and a RF5110G amplifier.



  3. #3
    Full Member level 2
    Points: 999, Level: 7

    Join Date
    Jun 2018
    Location
    Turkey
    Posts
    144
    Helped
    14 / 14
    Points
    999
    Level
    7

    Re: Star topology chipset for long range (high power) comms

    Quote Originally Posted by ArticCynda View Post
    As it can help others, I've settled for the combination of a Nordic Semi nRF905 front-end chip and a RF5110G amplifier.
    Just asking out of curiosity, isn't that power level is above ISM allowed power levels?



    •   AltAdvertisement

        
       

  4. #4
    Advanced Member level 1
    Points: 3,240, Level: 13

    Join Date
    May 2013
    Posts
    424
    Helped
    82 / 82
    Points
    3,240
    Level
    13

    Re: Star topology chipset for long range (high power) comms

    Quote Originally Posted by ktr View Post
    Just asking out of curiosity, isn't that power level is above ISM allowed power levels?
    That's a good question. I'm not an expert in the matter, but the way I interpret the rules, there are no power level limitations in ISM bands. They are designed for industrial, scientific and medical applications which use very strong RF transmitters such as for example microwave ovens. Your microwave oven emits about 800W at 2.45 GHz, so any limitation of power levels in ISM bands would de facto make microwave ovens unusable.

    The downside is that devices operating in ISM bands need to be interference tolerant for the same reason.



    •   AltAdvertisement

        
       

  5. #5
    Super Moderator
    Points: 83,103, Level: 70
    Achievements:
    7 years registered
    Awards:
    2nd Helpful Member
    betwixt's Avatar
    Join Date
    Jul 2009
    Location
    Aberdyfi, West Wales, UK
    Posts
    13,668
    Helped
    4536 / 4536
    Points
    83,103
    Level
    70

    Re: Star topology chipset for long range (high power) comms

    Hopefully your microwave oven doesn't radiate 'outside the box' though!

    Brian.
    PLEASE - no friends requests or private emails, I simply don't have time to reply to them all.
    It's better to share your questions and answers on Edaboard so we can all benefit from each others experiences.



  6. #6
    Super Moderator
    Points: 264,284, Level: 100
    Awards:
    1st Helpful Member

    Join Date
    Jan 2008
    Location
    Bochum, Germany
    Posts
    46,187
    Helped
    14045 / 14045
    Points
    264,284
    Level
    100

    Re: Star topology chipset for long range (high power) comms

    the way I interpret the rules, there are no power level limitations in ISM bands.
    Completely wong. There are limits for specific bands and applications, according to national (e.g FCC in the US) or regional (e.g. ETSI in Western Europe) regulations.


    1 members found this post helpful.

  7. #7
    Full Member level 2
    Points: 999, Level: 7

    Join Date
    Jun 2018
    Location
    Turkey
    Posts
    144
    Helped
    14 / 14
    Points
    999
    Level
    7

    Re: Star topology chipset for long range (high power) comms

    Quote Originally Posted by ArticCynda View Post
    That's a good question. I'm not an expert in the matter, but the way I interpret the rules, there are no power level limitations in ISM bands. They are designed for industrial, scientific and medical applications which use very strong RF transmitters such as for example microwave ovens. Your microwave oven emits about 800W at 2.45 GHz, so any limitation of power levels in ISM bands would de facto make microwave ovens unusable.

    The downside is that devices operating in ISM bands need to be interference tolerant for the same reason.
    Well, as a matter of fact I design MW products in ISM bands; and as far as I know +20 dbm is the commercial limit for most of the ISM bands; and there is also a limit on ACPR and EIRP. You should take a look at the regulations before continuing your design.


    2 members found this post helpful.

    •   AltAdvertisement

        
       

  8. #8
    Advanced Member level 1
    Points: 3,240, Level: 13

    Join Date
    May 2013
    Posts
    424
    Helped
    82 / 82
    Points
    3,240
    Level
    13

    Re: Star topology chipset for long range (high power) comms

    Thanks for the feedback everyone, it appears I missed a part of the regulation concerning specific ISM applications designed as RF transmitters. ktr, thanks for the referral. Indeed in the 433 MHz band, the limit is apparently 10 dbm (= 10 mW). I'm exceeding this by a factor 150 now so will have to look for a more sensitive receiver instead.

    - - - Updated - - -

    Quote Originally Posted by betwixt View Post
    Hopefully your microwave oven doesn't radiate 'outside the box' though!
    Mine definitely does, as evidenced by the fact that wifi in the entire house goes down while it's running. It's an older model though so perhaps not very well shielded.



  9. #9
    Advanced Member level 5
    Points: 34,414, Level: 45

    Join Date
    Oct 2001
    Posts
    4,918
    Helped
    1461 / 1461
    Points
    34,414
    Level
    45

    Re: Star topology chipset for long range (high power) comms

    ETSI regulations applies for entire Europe (and many other countries from all over the world as associates or observers), not only Western Europe.

    https://en.wikipedia.org/wiki/ETSI#/...membership.png


    1 members found this post helpful.

--[[ ]]--