FOAM is a personal spatial location tracking protocol and associated data marketplace, based on Ethereum. FOAM aims to solve three key problems of existing spatial protocols: inconsistent location encoding standards; poor user experience for spatial applications, and secure verification of the authenticity of the location data. Location data will be accessible and verifiable within an Ethereum smart contract. The platform will also develop a token curated registry (TCR) for geographic Points Of Interest (POI). The native FOAM token will provide curation rights to this TCR and to incentivize user maintenance of hardware beacon nodes that maintain local location data. FOAM is motivated by the vision of an open, non-rent-seeking, protocol for decentralized and privacy-preserving location data. This independent alternative endeavors to be more accurate and secure then GPS technology, which is supported by aging U.S. satellites. FOAM aims to provide a location standard that can be incorporated into an ecosystem of applications.
FOAM’s notion of Crypto-Spatial Coordinates (CSCs) represents a move towards a standardized means of linking a blockchain address to a physical location. A geohash and an Ethereum address are together encoded into a CSC. A CSC maps to a physical space of roughly one square meter and allows dApps to effectively interact with information about specific locations, reliably, and in a publicly verifiable manner. In order for a distributed network of relatively independent individuals to decide on the same set of physical places they consider to be important, FOAM opts for a Proof of Location based on a TCR.
The primary network participants are consumers (interested in POIs), candidates (want to be POIs) and cartographers (FOAM token holders who determine POIs). Once a prospective cartographer has deposited some FOAM tokens in a smart contract, they are able to suggest a POI. A challenge period follows this, during which any other participant in the network can challenge this choice of POI by staking an equivalent amount of tokens to the POI proposer. This can initiate a voting period amongst FOAM token holders that determines whether a POI is ultimately included.
Dynamic Proof of Location alluded to as a potential development later in the FOAM network’s life, will incorporate token holders ‘signaling’ demand for information around certain areas via further staking. Stake duration will influence a signal’s strength. Miners working towards consensus for areas signaled to be in demand will stand to earn increased rewards. Network actors, who provide radio beacons (‘anchors’) and proliferate their signal (‘authorities’), must be sufficiently incentivized for Dynamic Proof of Location to function. This network of beacons can allow for the geometric computation of locations relative to one another via a Byzantine Fault Tolerant clock. A critical mass of adoption is required for FOAM to offer real-time secure location services to a significant portion of the globe.
FOAM token holders will also be able to vote on parameters determining the TCR, such as the duration of the challenge period for new POIs. FOAM operated a token sale with KYC processes via Token Foundry, in the absence of a pre-sale, discount structure or bounties. A Proof of Use function, whereby FOAM token holders must participate in cartography, will be required to demonstrate the tokens’ utility before they can be transferred. Should FOAM mature into a platform resembling Dynamic Proof of Location as outlined by the team, then Zone Authorities will be eligible to receive transaction fees for providing location services to the network in the form of ‘presence claims’. FOAM tokens must be staked to contribute, either through directly providing location data or by contributing to the consensus mechanism. Of the total 1 billion FOAM tokens to be created: 30% were sold during the TGE; 35% for mining rewards (towards Dynamic Proof of Location) for Zone anchors; 25% set aside for ‘compensatory purposes’; 10% in a Reserve for FOAM protocol development, in the form of developer grants or otherwise. In May 2019, the project began offering grants, worth up to $15,000 per grant, to developers in exchange for contributing to the project.