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CC1120: Looking for kind of 'Mini-Mesh' to connect units...

GGA
Genius 3985 points
Part Number: CC1120
Other Parts Discussed in Thread: WI-SUN

Maybe this is the wrong forum, so I'll be happy to be forwarded to somewhere that fits better.
----

Given a topology, where we have a 434MHz RF system consisting of actors, sensors, keyfobs and concentrators (gateways).
The gateway, based on a Linux SoM plus a CC1120-434MHz sub-part, is used for key management, hosting a webbrowser, Ethernet, BLE, ...
But given that a topology (hospital, schools) won't fit into one 434MHz network due to distances, it will be neccessary to deploy multiple gateways.

Now customer expect that the system -regardless on the number of gateways- shows itself at one system, so connecting to a gateway via BLE / Ethernet plug/ WiFi they want to be able to control all gateways (and e.g. all window opener at once) deployed in that total system. We could certainly limit the number of gateways to <10.

Now we need to decide how to establish the intererconnect between gateways (cable is customer-no-go / same for joing a local WLAN):

- Full mesh with all the problems during deployment? Without having a stable bullet proof mesh OS (I know about e.g. Contiki, but its a toolkit, where nobody beside perhaps Adam really knows whats going on inside)? No chance for us to support in an industrial environment.
- Full mesh based on ready-to-use Mesh-modules? They have ~110dB link budget. How to to setup a topology in large buildings without spending dozens of repeater-mesh-modules?

- Narrowband IoT with 5G? Great link budget. But pretty new, don't want to be the first fool ;-) Needs a SIM card and always a working connection through a provider network to a cloud which then handles the MQTT messages. Lots of "if's" and customers don't like SIM cards

- CC1120-CC1190 tandem FEM on 868MHz with ~150dBm link budget? RF-wise interesting, but we need to develop all the media access / protocol stuff on our own - I've been through it in the past, this is not fun.

Maybe you guys have hints..?

thx!

  • 0
    TI__Genius 14845 points

    Hi GGA, 

    If you want to see an overview of the technologies we support for the sub-1 GHz communication, please visit the sub-1 GHz overview page. Here you can also compare the technologies to find the best fit for you. 

    Thanks, 
    Elin

  • 0 in reply to Elin W
    Genius 3985 points

    Hi,
    looking at the overview page (and what I have in mind with the last >5 years of following TI's software stacks) I do not see anything 'meshed' beside WI-SUN and 'propietary'.

    WI-SUN is, as I understand, more a FAN network system (far beyond what I'm looking for) and almost unkown to me (efforts to get started and to rollout).
    Proprietary: this is what I want to avoid: something where I don't know exactly what the output will be, taking weeks to figure out (I went through it with Contiki over month).

    Zigbee/Thread isn't even mentioned, but I know TI did support it in the past. But to what extend, how many work do one have to invest to get it up and running?
    That lead me to my basic question: isn't there a SUB-GHZ meshed software stack, that can be used AS-IS on a given TI chip?
    I just want to use it as a node processor, where I can drop/receive data and the unit takes care about the rest?

    In detail my requirements:
    - max. 4 hops
    - latency < 4s for 4 hops
    - datarate > 2kbyte/s

    thx. again

  • 0 in reply to GGA
    TI__Genius 14845 points

    Hi GGA,

    We still have support for Zigbee and Thread in the 2.4 GHz frequency band, you can read all about Zigbee here and Thread here, 

    GGA said:
    isn't there a SUB-GHZ meshed software stack, that can be used AS-IS on a given TI chip?

    Unfortunately not. Do you have a strict requirement for using both Sub-1 and mesh? 

    Thanks,
    Elin

  • 0 in reply to Elin W
    Genius 3985 points

    Elin,

    Sub-G is a must due to in-building topology, where 2.4 is simple lausy.

    Mesh? Isn't a must, but what else shall I use to connect multiple concentrators (e.g. gateways in our wording) wihout knowing the building topology upfront?!
    A star network requries decent planning and at least one point reachable by all others.
    If I shoot for that, I could use LoRa or something else with high link budget (yes, I shouldn't mention LoRa in a TI forum, I know).

    Zigbee is very old fashioned and does not support Sub-G (just on paper), Thread is unknown to us and a bit exotic.
    But the biggest hurdle is: both are toolkits / SW stacks where one needs to hope that it works. If a problem occurs, there is nobody for reliable support.

  • 0 in reply to GGA
    TI__Genius 14845 points

    Hi GGA, 

    GGA said:
    Sub-G is a must due to in-building topology, where 2.4 is simple lausy.

    I don't understand what you mean here, can you explain? There are many instances where 2.4 GHz is used indoors, what are your concerns, building/wall penetration?

    GGA said:
    Mesh? Isn't a must, but what else shall I use to connect multiple concentrators (e.g. gateways in our wording) wihout knowing the building topology upfront?!

    Thanks for sharing. Sounds like mesh is a must for you then. 

    GGA said:
    If a problem occurs, there is nobody for reliable support.

    We are supporting the Thread and Zigbee stacks from TI, so if you encounter any issues feel free to create an E2E post and we will do our best to support you. 

    Thanks,
    Elin