This document describes the architecture and technical roadmap planned for converting existing Approved Hotspots to Light Hotspots. As part of this migration, we have introduced a new Hotspot variant onto the network, called a Data Only Hotspot. More details on progress and timeline are listed below.
This project is in progress and subject to change. Last updated Wednesday December 6, 2021.
For real-time development and community support of Data Only Hotspots and Light Hotspots, please join the #gateway-development 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 has been moved off of physical Hotspots and onto Validators as of July 8, 2021. This simplifies the architecture and enables 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, activated as of July 20, 2021, to satisfy the increasing demand and continue to expand network coverage.
As of October 11 2021, Data-Only Hotspots can mine HNT for forwarding data packets on the network.
|Rewards Type||Data Only Hotspots||Full & Light Hotspots|
|Network Data Forwarding||YES||YES|
|Proof of Coverage||NO||YES|
Light Hotspot Properties
When the Light Hotspot Client is 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 no longer depend on libp2p or "gossip", and instead use gRPC, a new framework to communicate between distributed systems;
- Will be eligible to earn $HNT (see table below)
In other words, the client will allow the Hotspot to participate as a Full Hotspot, without the extra overhead of maintaining a local copy of the blockchain.
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-developement channel on the
Helium Discord Server.
The development of Light Hotspots will be broken up into the five following milestones.
Milestone 1: 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.
Milestone 1.5: Add Hotspot to Blockchain
- Target Completion: early July
- Status: COMPLETE
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.
Milestone 2: Earn HNT For Device Packet Transfer
- Target Completion: Fall 2021
- Status: Development Complete (Oct 11, 2021)
Data Only Hotspots will earn $HNT for device data transfer.
Path to Milestone 3 and Milestone 4
Work for both Milestone 3 and 4 are under way. The core team is currently focused on transitioning Full Hotspots to Light Hotspots due to the increasing size of the network and the amount of work needed to sustain this large peer-to-peer network.
Milestone 3: Light Hotspots as a new Hardware variant
- New Hardware Available to Customers: Starting in 2022, depending on Manufacturer
- Status: HIP-19 Makers undergoing Hardware Audit
Approved Hotspots from HIP19-approved manufacturers with lower compute requirements can be added to the network and participate in PoC.
Rough Timeline for Light Hotspot Makers:
- Submit HIP-19 Application to DeWi
- Pass KYC
- Enter queue for Hardware Audit
- Pass Hardware Audit/obtain any related certifications
- Load latest
gateway-rsbuild on manufacturing line
- Manufacture Light Hotspots
HIP-19 Makers: Hardware Audit will commence as soon as early December. Milestone 3 completion is not required for Audit. Please contact MOC for more details.
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)
Milestone 4: Software Update to Existing Hotspots to transform them into Light Hotspots
- Target Completion: Q1 2022
- Status: Development in Progress
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.
Hotspots will not need to follow the Blockchain.
Work on Milestone 4 has already started, please see Path to Milestone 3 and 4 above.