A study of the spectrum resource leasing method based on ERC4907 extension

The ERC4907 standard enables rentable Non-Fungible Tokens (NFTs) but is limited to single-user, single-time-slot authorization, which severely limits its applicability and efficiency in decentralized multi-slot scheduling scenarios. To address this limitation, this paper proposes Multi-slot ERC4907 (M-ERC4907) extension method. The M-ERC4907 method introduces novel functionalities to support the batch configuration of multiple time slots and simultaneous authorization of multiple users, thereby effectively eliminating the rigid sequential authorization constraint of ERC4907. The experiment was conducted on the Remix development platform. Experimental results show that the M-ERC4907 method significantly reduces on-chain transactions and overall Gas consumption, leading to enhanced scalability and resource allocation efficiency.

💡 Research Summary

This paper addresses a significant limitation in blockchain-based Dynamic Spectrum Sharing (DSS) systems by proposing an extension to the ERC4907 standard, termed Multi-slot ERC4907 (M-ERC4907). The core problem identified is that while ERC4907 enables rentable Non-Fungible Tokens (NFTs) by separating ownership from usage rights, it only supports authorizing a single user for a single, contiguous time slot per transaction. This “sequential authorization” constraint creates inefficiency and impracticality in real-world DSS scenarios where a spectrum resource (tokenized as a Non-Fungible Spectrum Token - NFST) needs to be leased to multiple users across multiple, discrete future time slots simultaneously.

The proposed M-ERC4907 method introduces two key novel functionalities to overcome this limitation. First, it allows the Primary User (PU), or spectrum owner, to pre-configure multiple non-overlapping idle time slots for a single NFST in a batch operation via a new setSpectrumIdleTime function. Second, and most crucially, it enables the simultaneous batch authorization of multiple users to their respective winning time slots through a batchSetUser function. This eliminates the sequential dependency, allowing all slots to be allocated in parallel after an auction concludes.

The system model integrates these smart contract extensions into a decentralized DSS framework involving a PU, multiple Secondary Users (SUs), a tokenization module (minting spectrum into NFSTs), and an auction module. The process flow involves: 1) PU minting an NFST, 2) batch-setting future idle slots, 3) initiating a multi-slot synchronous English auction, 4) SUs bidding in parallel for specific slots, 5) the smart contract automatically awarding all slots to the highest bidders in a single batch operation upon auction closure, and 6) automatically resetting user rights upon slot expiration.

Experimental validation was conducted on the Remix development platform, comparing gas consumption and transaction counts between standard ERC4907 and the M-ERC4907 method for authorizing user rights across a varying number of time slots (1 to 10). The results demonstrate that while M-ERC4907 incurs slightly higher overhead for one or two slots due to batch operation setup costs, its efficiency gains become substantial as the number of slots increases. ERC4907 exhibits a linear, steep increase in gas consumption (approximately 26,270 gas per additional slot), whereas M-ERC4907 shows a much more gradual rise (approximately 5,409 gas per additional slot). This proves that the batch authorization mechanism significantly reduces on-chain transactions and overall gas costs in multi-slot scenarios.

In conclusion, the M-ERC4907 extension effectively breaks the rigid sequential authorization model of ERC4907, enabling efficient, parallel, and scalable spectrum resource leasing. It enhances the practicality of blockchain-based DSS by reducing operational costs and improving resource allocation throughput, making it a viable solution for real-world multi-user, multi-slot spectrum sharing markets.