Ethereum developers are already implementing code for Constantinople, the network's next system-wide upgrade.

The second part of a series of upgrades to make the ethereum network more efficient and less costly in terms of fees, Constantinople will be activated sometime before October's Devcon4 ethereum conference, according to stakeholders during a core developer meeting Friday.

That said, an exact block number at which the code would go live hasn't yet been confirmed for the backward-incompatible change.

A loose roadmap for the upgrade has also been suggested. Under that roadmap, the implementation stage continues until August 13, after which there will be two months of testing, including the launch of a Constantinople-specific test network.

The upgrade will include various optimizations aimed at making the platform more efficient – and less costly in terms of fees. Constantinople is the second part of a two-part series of upgrades, following in the footsteps of Byzantium, which was activated last October.

According to the meeting, a total of four ethereum improvement upgrades (EIPs) are currently being implemented by developers. Péter Szilágyi, lead developer of Geth, the most popular ethereum client, said they have already implemented most of the changes.

"The EIPs are mostly done," Szilágyi said in the meeting.

Some of the upgrades that have reached the implementation stage include EIP 210, which reorganizes how block hashes are stored on ethereum, and EIP 145, which increases the speed of arithmetic in the ethereum virtual machine (EVM). Two other upgrades – EIP 1014 for the addition of ethereum state channels, and EIP 1052, a new op-code that compresses how contracts interact – are also being worked on by developers.

Two other notable changes are still up for discussion, including a possible delay in ethereum's difficulty bomb and an EIP that could improve how gas pricing works.

At least as far as the mining difficulty question is concerned – a contentious topic that involves a consideration of ethereum's issuance model and one that has different impacts on various stakeholders – no decision has yet to be made.

"We're not going to be able to decide this part today," Hudson Jameson, moderator of the discussion, concluded.

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