Ethereum Layer 2 scaling solution Optimism has scheduled its Bedrock upgrade for June 6 at 16:00 UTC. The upgrade will require between two and four hours of downtime for the OP mainnet, the team said in a May 16 announcement.

Before the Bedrock sequencer spins up, deposits and withdrawals will be paused and transactions on the old sequencer will no longer be accepted. Meanwhile, smart contracts on the Layer 1 will be upgraded and an irregular state transition applied to the Layer 2 chain.

The Optimism team expects the upgrade to bring down usage fees significantly, making the ecosystem more accessible. In a March blog post, the team said it estimates Bedrock to reduce protocol costs and security fees by 47% on the mainnet. 

It will achieve this by batching and compressing data, retaining only essential amounts of metadata for L1 transactions and breaking down L2 transactions into channel frames.

“Slicing channels into frames lets us handle very large L2 transactions by sending these transactions to the L1 in parallel, thus packing the corresponding L1 transaction as full as possible,” explained Optimism.

The upgrade will further minimize the usage of Ethereum gas by removing all execution gas and reducing L1 data fees to its theoretical minimum. When EIP-4844 is deployed on Ethereum, these costs could be brought down even further.

The team describes Bedrock as “the largest upgrade ever released” on Optimism, seeing as it has involved a complete rewrite of the entire rollup stack.

Optimism’s codebase has been adopted by Coinbase’s Layer 2 network Base, which makes a successful upgrade equally as crucial for Base. Jesse Pollak, Coinbase protocol engineer, called Bedrock a “pre-requisite” for the Base mainnet.