{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:7NHZ3GIITN56Z5U757R6SGABA6","short_pith_number":"pith:7NHZ3GII","canonical_record":{"source":{"id":"2008.02313","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2020-08-05T18:46:36Z","cross_cats_sorted":[],"title_canon_sha256":"75df1636e9eddb60a25578bde3331c3b817333663ff971e535ae45bb669319bd","abstract_canon_sha256":"dec665dc2d4abc7d5b7b47146f171b08332c0475ff061cffe15c912d1af47517"},"schema_version":"1.0"},"canonical_sha256":"fb4f9d99089b7becf69fefe3e91801078bd47de810ea2b1bb3556dfd36494db6","source":{"kind":"arxiv","id":"2008.02313","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2008.02313","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"arxiv_version","alias_value":"2008.02313v1","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2008.02313","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"pith_short_12","alias_value":"7NHZ3GIITN56","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"pith_short_16","alias_value":"7NHZ3GIITN56Z5U7","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"pith_short_8","alias_value":"7NHZ3GII","created_at":"2026-07-05T01:25:03Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:7NHZ3GIITN56Z5U757R6SGABA6","target":"record","payload":{"canonical_record":{"source":{"id":"2008.02313","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2020-08-05T18:46:36Z","cross_cats_sorted":[],"title_canon_sha256":"75df1636e9eddb60a25578bde3331c3b817333663ff971e535ae45bb669319bd","abstract_canon_sha256":"dec665dc2d4abc7d5b7b47146f171b08332c0475ff061cffe15c912d1af47517"},"schema_version":"1.0"},"canonical_sha256":"fb4f9d99089b7becf69fefe3e91801078bd47de810ea2b1bb3556dfd36494db6","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T01:25:03.976235Z","signature_b64":"+xH0IGt1HV2uNaE33Vw+BigEvr56wA/9XxzCF1G7qhpwzogineYrRqu092CeJuB7E6oA3rFY/Wlkwebkak8nDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"fb4f9d99089b7becf69fefe3e91801078bd47de810ea2b1bb3556dfd36494db6","last_reissued_at":"2026-07-05T01:25:03.975717Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T01:25:03.975717Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2008.02313","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:25:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1Zh459mk3i1dMWEPZt3QlDFSQ0GhhPnTsABu5mwdWYgmk3dtD55F7j9qRYh8XKmZHP0D1HmdvfwaIFO6X/DCBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T12:42:05.116689Z"},"content_sha256":"d2cdbcb173bc419eb155244fa64a17bcfc4dfea1789698fa708c8ffd5d987872","schema_version":"1.0","event_id":"sha256:d2cdbcb173bc419eb155244fa64a17bcfc4dfea1789698fa708c8ffd5d987872"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:7NHZ3GIITN56Z5U757R6SGABA6","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Huffman-Coded Sphere Shaping for Extended-Reach Single-Span Links","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"eess.SP","authors_text":"David S. Millar, Ian Phillips, Keisuke Kojima, Kieran Parsons, Pavel Skvortcov, Toshiaki Koike-Akino, Wladek Forysiak","submitted_at":"2020-08-05T18:46:36Z","abstract_excerpt":"Huffman-coded sphere shaping (HCSS) is an algorithm for finite-length probabilistic constellation shaping, which provides nearly optimal energy efficiency at low implementation complexity. In this paper, we experimentally study the nonlinear performance of HCSS employing dual-polarization 64-ary quadrature amplitude modulation (DP-64QAM) in an extended reach single-span link comprising 200 km of standard single mode fiber (SSMF). We investigate the effects of shaping sequence length, dimensionality of symbol mapping, and shaping rate. We determine that the na\\\"ive approach of Maxwell-Boltzmann"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2008.02313","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2008.02313/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:25:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"B2TXqje/PK05t0VJ5h0W9pk9vaULUogi4ifgACczPWJXPHYxIOPVuZEaCie4Ws1HaRZjyr9yZoI1p31HhaIMAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T12:42:05.117201Z"},"content_sha256":"1d6c833b10c101ffb8cd64712446eb83d73eb9c742d2a3b025b24b3bbc1d7ab4","schema_version":"1.0","event_id":"sha256:1d6c833b10c101ffb8cd64712446eb83d73eb9c742d2a3b025b24b3bbc1d7ab4"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7NHZ3GIITN56Z5U757R6SGABA6/bundle.json","state_url":"https://pith.science/pith/7NHZ3GIITN56Z5U757R6SGABA6/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7NHZ3GIITN56Z5U757R6SGABA6/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-08-04T12:42:05Z","links":{"resolver":"https://pith.science/pith/7NHZ3GIITN56Z5U757R6SGABA6","bundle":"https://pith.science/pith/7NHZ3GIITN56Z5U757R6SGABA6/bundle.json","state":"https://pith.science/pith/7NHZ3GIITN56Z5U757R6SGABA6/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7NHZ3GIITN56Z5U757R6SGABA6/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:7NHZ3GIITN56Z5U757R6SGABA6","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"dec665dc2d4abc7d5b7b47146f171b08332c0475ff061cffe15c912d1af47517","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2020-08-05T18:46:36Z","title_canon_sha256":"75df1636e9eddb60a25578bde3331c3b817333663ff971e535ae45bb669319bd"},"schema_version":"1.0","source":{"id":"2008.02313","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2008.02313","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"arxiv_version","alias_value":"2008.02313v1","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2008.02313","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"pith_short_12","alias_value":"7NHZ3GIITN56","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"pith_short_16","alias_value":"7NHZ3GIITN56Z5U7","created_at":"2026-07-05T01:25:03Z"},{"alias_kind":"pith_short_8","alias_value":"7NHZ3GII","created_at":"2026-07-05T01:25:03Z"}],"graph_snapshots":[{"event_id":"sha256:1d6c833b10c101ffb8cd64712446eb83d73eb9c742d2a3b025b24b3bbc1d7ab4","target":"graph","created_at":"2026-07-05T01:25:03Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2008.02313/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Huffman-coded sphere shaping (HCSS) is an algorithm for finite-length probabilistic constellation shaping, which provides nearly optimal energy efficiency at low implementation complexity. In this paper, we experimentally study the nonlinear performance of HCSS employing dual-polarization 64-ary quadrature amplitude modulation (DP-64QAM) in an extended reach single-span link comprising 200 km of standard single mode fiber (SSMF). We investigate the effects of shaping sequence length, dimensionality of symbol mapping, and shaping rate. We determine that the na\\\"ive approach of Maxwell-Boltzmann","authors_text":"David S. Millar, Ian Phillips, Keisuke Kojima, Kieran Parsons, Pavel Skvortcov, Toshiaki Koike-Akino, Wladek Forysiak","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2020-08-05T18:46:36Z","title":"Huffman-Coded Sphere Shaping for Extended-Reach Single-Span Links"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2008.02313","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:d2cdbcb173bc419eb155244fa64a17bcfc4dfea1789698fa708c8ffd5d987872","target":"record","created_at":"2026-07-05T01:25:03Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"dec665dc2d4abc7d5b7b47146f171b08332c0475ff061cffe15c912d1af47517","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"eess.SP","submitted_at":"2020-08-05T18:46:36Z","title_canon_sha256":"75df1636e9eddb60a25578bde3331c3b817333663ff971e535ae45bb669319bd"},"schema_version":"1.0","source":{"id":"2008.02313","kind":"arxiv","version":1}},"canonical_sha256":"fb4f9d99089b7becf69fefe3e91801078bd47de810ea2b1bb3556dfd36494db6","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"fb4f9d99089b7becf69fefe3e91801078bd47de810ea2b1bb3556dfd36494db6","first_computed_at":"2026-07-05T01:25:03.975717Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:25:03.975717Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"+xH0IGt1HV2uNaE33Vw+BigEvr56wA/9XxzCF1G7qhpwzogineYrRqu092CeJuB7E6oA3rFY/Wlkwebkak8nDg==","signature_status":"signed_v1","signed_at":"2026-07-05T01:25:03.976235Z","signed_message":"canonical_sha256_bytes"},"source_id":"2008.02313","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d2cdbcb173bc419eb155244fa64a17bcfc4dfea1789698fa708c8ffd5d987872","sha256:1d6c833b10c101ffb8cd64712446eb83d73eb9c742d2a3b025b24b3bbc1d7ab4"],"state_sha256":"56b826ffc66cc5d6c5fcff27b57e36f6668a0abb981fe05eebd99cb928e41814"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"3ByVLL6RkkbFdtpomBwMTSycyjmZh4Qat5Bs6FKYkab+6q8WDpE4rEH4j6RNaHx8RlAWHdG3ko7Ma0fA92RPBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-04T12:42:05.121512Z","bundle_sha256":"8e01f49e7c8cf0d66d9a18bf183c7d4e9deb66c51b39c21835f099429496436b"}}