This document describes the architecture and technical roadmap planned for converting exisiting Approved Hotspots to Light Hotspots. As part of this migration, we will also introduce a new Hotspot variant onto the network, called a Data Only Hotspot (more below).
This project is in progress and subject to change.
For real-time development and community support of Data Only Hotspots and Light Hotspots, please join the #gateway channel on Helium Discord
What is a Light Hotspot?
Light Hotspots are the evolution of how LoRaWAN gateways will interact with the Helium blockchain. Since the genesis block, the Helium blockchain has run entirely on the physical Hotspot itself. As the blockchain network grows, each Hotspot running a full node undergoes increasing load and are starting to fall out of sync due to the higher compute requirements.
To mitigate this, the Hotspot's consensus work will be moved off of physical Hotspots and onto Validators. This will simplify the architecture immensely, an enable us to grow the Network exponentially while keeping blocktimes and epochs stable.
As all approved Hotspots transition to a Light Hotspot architecture, we also introduce a new type of Hotspot known as Data Only Hotspots to satisfy the increasing demand and continue to expand network coverage.
Light Hotspot Properties
When Light Hotspots are fully developed and in production (which will happen with the completion of Milestone 4 detailed below) they will satisfy the following properties:
- A Hotspot on the Helium network that, via Validators, can participate in PoC beacons and witnesses, and forwards data packets;
- Does not store a copy of the Blockchain, eliminating synchronization;
- Does not create challenges (relies on Validators to create challenges on their behalf);
- Does not participate in Consensus Groups (relies on Validators for block production);
- Will be eligible to earn $HNT(see table below)
Data Only Hotspots
With the introduction of the Light Hotspot, we also introduce a new type of Hotspot Miner on the Helium Network, namely a Data Only Hotspot that is a LoRaWAN Gateway running gateway-rs, that earns $HNT for device packet transfer.
This image shows the progression to Light Hotspots, with the role of Miner being deprecated as we move the blockchain off the Hotspots and into the Validator infrastructure. At the conclusion of Milestone 4, the entire Helium blockchain, and the coordination of Proof of Coverage, will be handled by Validators.
Code and Development
The bulk of the code that enables Light Hotspots on actual LoRaWAN gateways is called gateway-rs. It's easiest to think of this as Helium's next-generation packet forwarder.
Development of this code takes place in the above GitHub repo, as well at the
#gateway channel on the Helium Discord Server.
The development of Light Hotspots will be broken up into the five following milestones.
Free Packet Forwarding
- Target Completion Date: March 18
- Status: COMPLETE
At the completion of Milestone 1, any LoRaWAN gateways running gateway-rs can route packets to and from the Helium Network but not earn HNT. This means an DIY gateway can send and receive data on the Network. These LoRaWAN Gateways running Gateway-rs are known as Data Only Hotspots.
Add Hotspot to Blockchain
- Target Completion: June
- Status: IN DEVELOPMENT
At the completion of Milestone 1.5, Data Only Hotspots can be added to the blockchain, assert its location, and be seen on explorer.helium.com.
Data Only Hotspots are added to the blockchain by paying a $10 Add Gateway transaction fee, and a $5 Assert location transaction fee using the Helium Wallet CLI and will not earn $HNT.
Earn HNT For Device Packet Transfer
- Target Completion: Summer 2021
- Status: NOT YET STARTED
Data Only Hotspots will earn $HNT for device data transfer.
Introduction of Light Hotspots
- Target Completion: Post Milestone 2
- Status: NOT YET STARTED
At this point, Approved Hotspots from HIP19-approved manufacturers with lower compute requirements can be added to the network and participate in PoC. (Kerlink is the first approved maker to submit a light hotspot design.)
Onboarding for these Light Hotspots will be done via the standard Helium Wallet app onboarding. The fees will be equivalent to other Approved Hotspots ($40 and $10 for add assert, respectively).
At this stage, there will be three types of Hotspots:
- Approved Hotspot (HIP-19 approved, earns HNT for PoC and Data Transfer, follows Blockchain)
- Light Hotspot (HIP-19 approved, earns HNT for PoC and Data Transfer)
- Data Only Hotspot (DIY LoRaWAN Gateway, earns HNT for Data Transfer)
All Approved Hotspots Operate as Light Hotspots
- Target Completion: Post Milestone 3
- Status: NOT YET STARTED
In the final milestone, all Approved Hotspots on the Network will be converted to run gateway-rs and will be dependent on Validators to generate challenges and process witness receipts.
All Hotspots will not need to follow the Blockchain.
Data-Only Hotspot Setup Guides
- Dragino LPS80/DLOS8
- Draginos will only mine HNT as a Data Only Hotspot
- Kerlink gateways
- Kerlink gateways will only mine HNT as Data Only Hotspot unless it is specified as a Helium-Compatible Kerlink Miner.
Gateways running a Packet Forwarder and Miner is not considered a Light Hotspot and will never earn HNT.