How does PoCv11 work?
Helium blockchains, powered by PoCv11, can receive regulatory and configuration parameters via chain variables that can be controlled through governance. Those parameters are also enforced so that Hot spot owners adhere to local transmission requirements.
What is the purpose of POC?
Helium blockchain participants use Proof-of-Coverage to verify hot spots are where they say they are. The Hot spot chain needs to verify that each location is created by another Network participant continuously so that it can reward the Hot spot for contributing to coverage.
While the LoRaWAN PoC Protocol uses similar packets, it can run at different power and spreading factor settings than typical devices. As before, PoCv11 changes do not affect real device traffic, and Hotspots continue to earn money from Data Transfer.
Up until PoCv11, the blockchain didn’t support regional LoRaWAN parameters, and only supported US and EU power settings. PoCv11 is capable of looking up regional information, EIRP (Effective Isotropic Radiated Power), and channel plans based on H3 indices. Helium blockchain maps geographical coordinates to indexed locations by using Uber’s H3 hexagonal grid system The blockchain-core developers have added H3 -> LoRaWAN Region -> LoRaWAN Region Parameter lookup support to blockchain-core, thanks to the very impressive work by @gradoj in their hplans repo (creates mappings between GeoJSON and LoRaWAN regions).
Through governance, these chain variables can be adjusted accordingly as the Network grows into regions without a regional plan or as LoRaWAN specifications change.
You can review the currently proposed vars here in draft form. In the days to come, these variables may change as we do final testing and verification.
Witness / Record Validation using PoCv11
Other new features in PoCv11 include a consideration of the asserted antenna gain for hotspots. By the time PoCv11 is activated, the blockchain will also take into account asserted antenna gains when calculating Free Space Path Loss and confirming PoC receipts and witness validity.
Prior to PoCv11, a gain of 1.2 dBi was assumed when validating every receipt/witness transmission. While the 1.2 dBi is still the default gain, the chain will now operate using region-specific EIRP to ensure that witness/receipt transmissions are factored correctly. In some regions, transmit power will be reduced to comply with local limits, but the gain will improve validation on the receiver side. For example, in the US, the maximum EIRP is 36 dBm and the hardware is able to transmit at 27 dBm. If you’re operating a 9 dBi antenna, you can assert it without any transmission power loss. The chain variables have this configured for each region and frequency.
It is in the best interest of Hotspot owners and the Network to accurately set their antenna gains.
Verifying asserted locations and identifying likely coverage are the objectives of PoC. For this to occur, it must make sure that illegal transmissions (i.e. transmissions with a higher power than the regional specific EIRP) are considered invalid and will not earn any rewards. Calculated through FSPL.Also, by validating the receipts and witnesses, all the transmissions are contained within one of the LoRaWAN regions or channel plans.
Thus any spurious transmissions going beyond region boundaries will also be considered invalid.
To show how rewards might be affected for Hotspots once PoCv11 is live, the team has been developing a visualizer. Soon, we will share it. This visualization will show the changes that could occur if Hotspot owners begin asserting their locations and antenna gains before PoCv11 is activated.
This is your call to action
In addition to being one of the largest upgrades to the Proof-of-Coverage system, this upgrade will improve the ability to collect and verify data. Using this upgrade, future improvements will be able to find Hotspot locations that are incorrectly asserted or spoofed. During the next few months and years, the Network will expand from 200K hotspots to 1M hotspots and beyond.
Help build The People’s Network by taking action on the items above!