Best protocol for a new star network

Riccardo Straga

Prodigy 45 points

Other Parts Discussed in Thread: CC2652P

Tool/software:

Hi,

We are doing some research to develop a new version of our wireless sensors.

We'd like to implement private networks with the following requirements :

1) Low consumption for the sensor nodes (battery powered + solar panel 0.3W) in the network, slightly higher consumption for the collector (battery + solar panel 2-5W).

2) Range >50m

3) We need to collect 1 to 2MB every day from each sensor

4) Around 30 sensors in each network

5) Ideally a Sub 1GHz band but also 2.4 GHz could be good (if the range doesn't drop too much in presence of obstacles) . We are concerned about duty cycles for Sub 1GHz.

6) Time synchronization between sensor and collector (ideally 1ms)

7) No problems of latency, sensor can wait until there collector is free to receive data.

We currently use a CC2652P for a PoC with BLE (LE Coded S=8) as protocol and we are quite happy. Anyway we'd like to switch to a free protocol to reduce the costs due the fact we don't need to interface with other BLE devices (the networks are private). Also if is possible we'd like to switch from 2.4Ghz to Sub 1Ghz bands to extend the range (change the MCU is not a problem).

We think that maybe the TI 15.4 stack could fit, but we'd like to have your opinion.

Thanks,

Riccardo

28 days ago

0 Marie H 23 days ago

TI__Guru* 77621 points

Hi Riccardo,

As you say, this sounds like a good fit for TI 15.4-Stack. We support several PHYs on both Sub-1 and 2.4 GHz bands.

If you want to use frequency hopping (as in BLE) you can use FH mode (we support sleepy nodes).

Cheers,

Marie H

0 Riccardo Straga 23 days ago in reply to Marie H

Prodigy 45 points

Hi,

thank you for the response.

If we choose PHY ID = 133 (standard ETSI) does the TI 15.4 Stack limit automatically the Tx to respect the duty cycle (and be compliant with the standard) ?

Thanks,

Riccardo S.

0 Marie H 22 days ago in reply to Riccardo Straga

TI__Guru* 77621 points

Hi RIccardo,

No we don't have an automatic regulation of duty cycle.

When you select ETSI as your region, the device will always do LBT before transmitting a packet.

If you use FH mode, it's possible to use the CERTIFICATION_TEST_MODE to test your channel occupancy.

If you use ARIB mode we have the option to control the duty cycle. But then you wouldn't be using the correct PHY.

Cheers,

Marie H

0 Riccardo Straga 21 days ago in reply to Marie H

Prodigy 45 points

Hi,

could you suggest any documentation to deeply understand the TI 15.4 Stack ?

Thanks,

Riccardo S.

+1 Marie H 21 days ago in reply to Riccardo Straga

TI__Guru* 77621 points

Hi Riccardo,

For a deep overview please see our Software Overview app note:

https://www.ti.com/lit/swra782

When you're ready to start developing I hope the User's Guide would be useful:

https://dev.ti.com/tirex/explore/node?node=A__AITUIbVTzCdD7w7KebQ-qA__com.ti.SIMPLELINK_CC13XX_CC26XX_SDK__BSEc4rl__LATEST&placeholder=true

Cheers,

Marie H

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

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Best protocol for a new star network