We plan to implement a decentralized storage at Callisto Network. I was researching SWARM for long enough. I like its main idea, but it has some problems that could not be solved: for example an issue of microtransactions. There is no solution for this problem unless you have free transactions. And transactions are not free at Callisto.
Explain, please .

What is not clear here? Refused from one way to solve the problem in favor of another. Or are you interested in what SWARM is?
As far as I know, SWARM is a mobile application for different platforms that allows you to share your location. "The introduction of a decentralized storage facility into the Callisto network." What will it give? "
Swarms broader objective is to provide infrastructure services for developers of decentralised web applications (dapps), notably: messaging, data streaming, peer to peer accounting, mutable resource updates, storage insurance, proof of custody scan and repair, payment channels and database services.
From the end users perspective, Swarm is not that different from the world wide web, with the exception that uploads are not hosted on a specific server. Swarm offers a peer-to-peer storage and serving solution that is DDoS-resistant, has zero-downtime, fault-tolerant and censorship-resistant as well as self-sustaining due to a built-in incentive system which uses peer-to-peer accounting and allows trading resources for payment. Swarm is designed to deeply integrate with the devp2p multiprotocol network layer of Ethereum as well as with the Ethereum blockchain for domain name resolution (using ENS), service payments and content availability insurance.
http://swarm-guide.readthedocs.io/en/latest/introduction.htmlI like its main idea, but it has some problems that could not be solved: for example an issue of microtransactions. There is no solution for this problem unless you have free transactions. And transactions are not free at Callisto.
As the result, it was decided to replace the SWARM implementation with EOS model of IPFS-host-nodes.