LoRa | Frequently Asked Questions (FAQ)

  • 12 August 2016
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Where should I start on this forum?
Please see this topic..

How do I get my LoRa keys?
LoRa keys refers to the identifiers required to join the (KPN) network. Depending on your account type there are different ways to get your keys:
  • For developers the keyset can be obtained via the KPN LoRa Developer Portal.
  • If you are connected to the KPN network via a reseller (e.g. SIMPoint), then contact the reseller.
  • For customers that are directly connected via KPN please contact your account manager.

What are the requirements for the AppSKey, NwkSkey & AppKey?
The keys should be 128 bits (RFC 4493, SAE 128-cmac). Implying 32 random hexadecimal characters. One can refer to the topic on online available LoRa tools for tools that can help in generating these keys. Note that keys should be random enough, so only 0's will not be accepted
code:
Example:'0bc47c37c8bdece9b221490835dbf9f4'


How do I get my LoRa Adress and Keys on my device?
This depends on the device used. Some devices use Arduino-like programmers to upload a script containing the Adress and Keys. Others use special programmers. Please refer to the manufacturer of your device for more info.

What are the URLs of the core platform of KPN
This platform can only be accessed by customers that are directly connected to KPN (so not via the developer portal or via a reseller).
For provisioning of devices the URL is https://www.kpn-lora.com/deviceManager and for monitoring of messages of your devices it is https://www.kpn-lora.com/wlogger.

What APIs are available?
Currently only data APIs are available to sent and receive LoRa Payload. KPN is working on securely offering APIs for provisioning and configuration.

Which dataformats are supported?
ThingPark supports XML and J-SON format. The Developer Portal supports only J-SON.

Can I use another IP-port than 443?
No. Currently only the use of port 443 is supported.

Can I reach my LoRa devices directly from the internet?
No. LoRa devices are not IP based and cannot be reached directly. You always have to go through a LoRa core server like KPN ThingPark.

Does an aknowledgment count as a downlink message?
Yes. KPN views aknowledgements as a downlink message.

What are the ports I see within LoRaWAN?
Messages are sent to and from devices using a LoRa port. Each port can have a different AppSKey and connected Application Server. Ports can have values 1-223. Other values are reserved for network and testing purposes.

How do I get an AS_ID and LRC-AS key?
Customers can generate their own AS_ID and LRC-AS key. The AS_ID should be a unique identifier for your Application Server (for instance 'MyLoRaServer'). The LRC-AS key is a 128 bits key for the use in SHA256 and should contain 32 random hexadecimal characters. (See also 'What are the requirements for the AppSKey, NwkSkey & AppKey?')

Can I fix the Spreading Factor?
Yes, you can fix the spreading factor for a device by switching off ADR (Adaptive Data Rate) on your device. This is only adviced for continuously moving devices.

What spreading factors can I use whithin the KPN network?
Please refer to the Spreading Factor, Time on Air and Adaptive Data Rate topic.

What are uplink and downlink messages?
Please refer to the Uplink and Downlink messages and the Duty Cycle topic.

What is the size of KPN LoRa packets?
The maximimum size that can be used all the time is 51 bytes. (When FOpts field within the LoRa packet is empty, this can be 54 bytes).

How should my payload data look like?
LoRa does not require any format on payload, other than it being hexadecimal.

Should I certify my device?
Please refer to the Certification and requirements of LoRaWAN devices topic.

What is the maximum number of message I can sent?
Devices should always obey the duty cycle. KPN offers serveral different bundles where the number of uplink and downlink message are given per device. Currently, the largest bundle offers 300 uplink messages per day. Sending more messages is possible, but you will be charged out-of-bundle costs per extra message.

What is the difference between indoor and outdoor coverage?
Indoor coverage largely depends on the type of building material used. As a rule of thumb “you should have LoRa coverage when you see (reflected) daylight”. Note however that certain kinds of window coatings can also have a significant blocking effect on radio signals.

Can I reach my device at any time?
This depends on the device class used.

When will my downlink message be delivered to my device?
This depends on the device class used.

Can I use my devices abroad / in other countries?
Many countries are now rolling out a LoRa network. Please refer to the LoRa Alliance Website to see which new members in your country are available. When roaming agreements between Alliance Members are available, this will be communicated with customers.

Which timestamp should be used for downlink messages?
Please refer to Setting up your Application Server topic.

What happens when the Application Server is not reachable?
The payload is forwarded directly to the Application Server and it is not stored on the LoRa Core server. In case the Application Server is not reachable, the data will be lost. It is possible to set multiple Application Servers where data should be forwarded to within a routing profile in ThingPark.

What is the maximum distance between device and gateway?
KPN has a nationwide LoRa network which covers The Netherlands. In case there appears to be a coverage issue, this can be reported to KPN such that appropriate measures can be taken.

What is ABP and OTAA?
Both are activation methods for your device to identify on the network. Please refer to the ABP and OTAA topics for more information.

Why does my device send its uplink message more than once?
The LoRa protocol has a retransmit setting. This is set to 3 as a default.

How do I send a downlink message?
Please refer to the Setting Up Your Application Server topic.

Can I use geolocation to locate my assets using LoRa?
Please refer to the Geolocationtopic

Useful links


- LoRa: Starters Guide
- LoRa: Forum and Manuals
- LoRa: Geolocation
- LoRa: Dictionary & Definitions
- Tools: www.LoRaTools.nl

11 reacties

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How is the SF calculated? Is see that I have very good radio conditions to a gateway, but still have a high SF?
SF is calculated over messages that are received by at least three gateways. So the gateways with the lowest radio condition determines the SF.


Can you please clarify this? You meant that during ADR only the messages received by at least 3 GW count, right?
There is a setting called 'Antenna diversity' that determines how many gateways are used to determine ADR.
The default setting is 3 which means that the ADR is determined in such a fashion that the message is still received by at least 3 gateways.
Where should I start on this forum?
What is the size of KPN LoRa packets?
The maximimum size that can be used all the time is 51 bytes. (When FOpts field within the LoRa packet is empty, this can be 54 bytes).
[/url]topic


Is there a reason why a package can only be 51 bytes? I know LoRa does not have a hight bandwith but as far as i know it is possible to send bigger packages but it wil take longer.

If 51 bytes is really the maxium I hope it means 51 paypload bytes? Not including the fields that the LoRaWAN protocol adds.
51 bytes is the maximum payload size when a device is sending on SF12 in order to obey the duty cycle. On higher spreading factors you can send more data but we always advice a payload smaller than 51 bytes so you don't run into trouble in an SF12 situation.

As for the comment on package vs. payload: the 51 bytes is related to the payload size, not the message as a total.
What are the different bundles with their respective message limitations as described here:

What is the maximum number of message I can sent?
Your device should always obey duty cycle. KPN offers serveral different bundles where the number of uplink and downlink message are given per device. Currently, the largest bundle offers 300 messages per day. Sending more is possible, but you will be charged additional cost per extra message.

Where could i find these?
Reputatie 7
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Hi Weffel,

Welcome to the LoRa Forum! :D

The different bundles with the number of uplink and downlink messages are not (yet) published on our website. I contacted one of the specialists and he gave me an explanation about the number of messages.
Unfortunately, I don't have the exact number of messages. There are 5 different bundles in total. The most regular bundle is around 100 uplink and 10 downlink messages per day.
The costs for bundles like this are around € 10,- per year. How many messages do you expect to need?
Hi Rick,
thank you for your response.


How many messages do you expect to need?


I expect multiple messages each hour and maybe some downlink messages each hour.. But there is no design yet. I'm still looking at all the possibilities before i design my system.

Is there a maximum size of the messages? Or are those 100 uplink and 10 downlink messages all 241 bytes payload? (as i understand that is the maximum for europe)
Reputatie 7
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Hi Weffel,

The question about the maximum size of the messages is has already been given in this topic.

51 bytes is the maximum payload size when a device is sending on SF12 in order to obey the duty cycle. On higher spreading factors you can send more data but we always advice a payload smaller than 51 bytes so you don't run into trouble in an SF12 situation.

Besides the advice for a payload smaller than 51 bytes, we maintain the European standard of 241 bytes. As you can see in the quoted message, the spreading factor is also an important condition.
It seems that the check on maximum number of messages per timeframe has been implemented on the developer portal (loradeveloper.mendixcloud.com) now to about 1 message / 10 minutes. Is that correct? I also saw mention of 3 messages / hour. What is the exact policy for the developer portal now? Previously I was able to send quite some more messages. I'm OK with any limit, as long as it is clear what it is :-)

Sorry if this has already been mentioned somewhere. I have searched the forum before asking the question. It seems not to be in the FAQ (except for the mention of the possible bundles and max 300 messages / day).
Regarding my own statement: " I'm OK with any limit, as long as it is clear what it is", is not entirely valid: For some use cases aspiring users might want to explore the coverage of the KPN network under certain difficult circumstances, in that case a wait of 10 minute after each successfully received transmission is quite awkward.
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Regarding my own statement: " I'm OK with any limit, as long as it is clear what it is", is not entirely valid: For some use cases aspiring users might want to explore the coverage of the KPN network under certain difficult circumstances, in that case a wait of 10 minute after each successfully received transmission is quite awkward.The best answer to your question is: exceptions will always be considered. 🙂
We have the possibility to increase the limit for an account. In a situation like you're explaining, I'm sure we'll raise the limit in that case. If you sent us a message / request with your motivation, we're happy to evaluate.

At the moment the downlink rate for the developer portal is limited to 3 downlinks per hour.
While working on the LoRa network, it's possible the limitation is disabled for a short period of time.

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