[HH] Semtech long range device using 2.4 GHz

[Kurt Keville]

True... maybe if we only had to buy 1 Semtech gateway to support a
field of a couple of dozen BLE devices (at any given time) that would
be pretty transparent to the consumer. You would likely need to get
them to download an app. I don't think you can get everything you
would want from just pairing requests.

We will find out pretty soon. Our TTN radios (finally) came in today
so we will perform the indoor test this week and next. Then by April
we will get them fielded out in Area 4 (and beyond if signal reaches).
On the indoor test we will try 3 forms of positioning. WiFi, BLE and
whatever we can get on the LoRa devices. I will see if get the kind of
positioning you described from the Semtech videos.

The biggest attraction of LoRa to my mind is the fact that it is on a
separate band. The physics of that band are good enough for the
functions you want in IoT comms but it also make it rather exclusive.

On Mon, Mar 20, 2017 at 9:27 AM, Stephen Ronan <sronan at gmail.com> wrote:
> "BLE in particular appears to do most of what the 2.4GHz LoRa fans would like."
>
> But a single ultra-lower power radio+antenna that can both communicate
> at 2Mbps with a bunch of BLE devices within a few hundred feet and
> intersperse that with occasional communications at 70 kbps to a
> mile-away gateway does have some appeal, doesn't it?
>
> On Mon, Mar 20, 2017 at 8:46 AM, Kurt Keville <klk at mit.edu> wrote:
>> I think Semtech might be confusing the cash cow and the loss leader in
>> TTN logistical support. We don't need LoRa on 2.4 GHz but it would be
>> nice if we had (really slow) Wireless Internet options on 900 MHz. I
>> don't anticipate ever buying another 2.4GHz radio, seeing as you get
>> them for free on seemingly every board you buy these days. BLE in
>> particular appears to do most of what the 2.4GHz LoRa fans would like.
>>
>> The low bandwidths on LoRa are a feature, not a fault. It makes us use
>> the network only for the appropriate functionalites.
>>
>> On Sun, Mar 19, 2017 at 10:24 PM, Stephen Ronan <sronan at gmail.com> wrote:
>>> Those Semtech 2.4 Ghz boards support LoRa, FLRC, and (G)FSK
>>> modulation. Someone who knows far more than I do about these matters
>>> explains that the 2 Mbps data rate I had cited is via the FSK
>>> modulation. While for LoRa the data rate depends on the spreading
>>> factor (SF) about which more here:
>>> https://www.thethingsnetwork.org/forum/t/how-spreading-factor-influence-time-on-air/5068
>>> Specifically, in respect to data rates he wrote:
>>>
>>> "for LoRa 2.4Ghz it's
>>>
>>> SF 5: 202 kb/s
>>> SF 6: 122 kb/s
>>> SF 7: 71 kb/s
>>> SF 12: 0.476 kb/s"
>>>
>>> On Sun, Mar 19, 2017 at 5:26 PM, Stephen Ronan <sronan at gmail.com> wrote:
>>>> I don't know what to make of this... a new product from Semtech (which
>>>> owns the core LoRaWAN patent) that uses 2.4GHz spectrum... and
>>>> advertises a "sensitivity, down to -132 dBm". The last of the links
>>>> below says:  "The new 2.4 GHz wireless RF solution enables
>>>> point-to-point wireless links that can support custom protocols with
>>>> configurable data rates up to 2 Mbps". By contrast, my understanding
>>>> is that their LoRaWAN products max out at something like 20 kbps.
>>>>
>>>> https://www.thethingsnetwork.org/forum/t/2-4-ghz-lora/6045
>>>> http://www.semtech.com/apps/product.php?pn=sx1280,
>>>> https://www.semtech.com/wireless-rf/24ghz-wireless-rf-solution
>>>>
>>>>  - Stephen
>>> _______________________________________________
>>> Hardwarehacking mailing list
>>> Hardwarehacking at blu.org
>>> http://lists.blu.org/mailman/listinfo/hardwarehacking
>> _______________________________________________
>> Hardwarehacking mailing list
>> Hardwarehacking at blu.org
>> http://lists.blu.org/mailman/listinfo/hardwarehacking