{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:QV2BY3ZWPPHRJIMCPF5PXYIGYQ","short_pith_number":"pith:QV2BY3ZW","canonical_record":{"source":{"id":"2106.11896","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2021-06-22T16:04:34Z","cross_cats_sorted":["eess.SP","math.IT"],"title_canon_sha256":"fc8eaf09ceef162f3b6de7bf50830a02112c9575a774f7d1f8e26fc85c7627a0","abstract_canon_sha256":"f2b992c4dc8eabf89ac1d07c714bb6803e4b82ed17950b364c80343a0637e9d1"},"schema_version":"1.0"},"canonical_sha256":"85741c6f367bcf14a182797afbe106c40fd97a083d2afeaf8c9184865b5b31ba","source":{"kind":"arxiv","id":"2106.11896","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2106.11896","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"arxiv_version","alias_value":"2106.11896v2","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2106.11896","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"pith_short_12","alias_value":"QV2BY3ZWPPHR","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"pith_short_16","alias_value":"QV2BY3ZWPPHRJIMC","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"pith_short_8","alias_value":"QV2BY3ZW","created_at":"2026-07-05T03:05:02Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:QV2BY3ZWPPHRJIMCPF5PXYIGYQ","target":"record","payload":{"canonical_record":{"source":{"id":"2106.11896","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2021-06-22T16:04:34Z","cross_cats_sorted":["eess.SP","math.IT"],"title_canon_sha256":"fc8eaf09ceef162f3b6de7bf50830a02112c9575a774f7d1f8e26fc85c7627a0","abstract_canon_sha256":"f2b992c4dc8eabf89ac1d07c714bb6803e4b82ed17950b364c80343a0637e9d1"},"schema_version":"1.0"},"canonical_sha256":"85741c6f367bcf14a182797afbe106c40fd97a083d2afeaf8c9184865b5b31ba","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T03:05:02.937354Z","signature_b64":"3bI5+oXJ3NI8ykLBsIPkeB8y3xh5umY+NG4zTY9Hwt+o2mzr/isUqm40SHggcXQ+kD8JcBZBSw1BpJLn8en/BQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"85741c6f367bcf14a182797afbe106c40fd97a083d2afeaf8c9184865b5b31ba","last_reissued_at":"2026-07-05T03:05:02.936906Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T03:05:02.936906Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2106.11896","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T03:05:02Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"c/IMYy/AhTGKpkPnJdS6yrsRHRFSVoAcL0ArBk1ywKBkfcsnWQeVs4IfuzfyI9uDd66pdkBO69N2eEKn42gRAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-05T11:12:25.133555Z"},"content_sha256":"04f8aee5bbf1d44c16652e97e103c4cfb91a64159efdb8174a9078f9be08ee3b","schema_version":"1.0","event_id":"sha256:04f8aee5bbf1d44c16652e97e103c4cfb91a64159efdb8174a9078f9be08ee3b"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:QV2BY3ZWPPHRJIMCPF5PXYIGYQ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Distributed Beam Training for Intelligent Reflecting Surface Enabled Multi-Hop Routing","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["eess.SP","math.IT"],"primary_cat":"cs.IT","authors_text":"Rui Zhang, Weidong Mei","submitted_at":"2021-06-22T16:04:34Z","abstract_excerpt":"Intelligent reflecting surface (IRS) is an emerging technology to enhance the spectral and energy efficiency of wireless communications cost-effectively. This letter considers a new multi-IRS aided wireless network where a cascaded line-of-sight (LoS) link is established between the base station (BS) and a remote user by leveraging the multi-hop signal reflection of selected IRSs. As compared to the conventional single-/double-hop IRS system, multi-hop IRS system provides more pronounced path diversity and cooperative passive beamforming gains, especially in the environment with dense obstacle"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2106.11896","kind":"arxiv","version":2},"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/2106.11896/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":"2026-07-05T03:05:02Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"t3ztfm1okWd6HXIIMlFWe0UClaN6iXyWM96izP0QNH81hIAh4zhhsOQLaq84BWhaQlfYFmzKQySaHP/FbYQZBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-05T11:12:25.134046Z"},"content_sha256":"4dabb6bfc9b465d84e411c6c73000fb7d2a6cca0fda0c1b09bfb1e4ad144da9f","schema_version":"1.0","event_id":"sha256:4dabb6bfc9b465d84e411c6c73000fb7d2a6cca0fda0c1b09bfb1e4ad144da9f"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QV2BY3ZWPPHRJIMCPF5PXYIGYQ/bundle.json","state_url":"https://pith.science/pith/QV2BY3ZWPPHRJIMCPF5PXYIGYQ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QV2BY3ZWPPHRJIMCPF5PXYIGYQ/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":"2026-08-05T11:12:25Z","links":{"resolver":"https://pith.science/pith/QV2BY3ZWPPHRJIMCPF5PXYIGYQ","bundle":"https://pith.science/pith/QV2BY3ZWPPHRJIMCPF5PXYIGYQ/bundle.json","state":"https://pith.science/pith/QV2BY3ZWPPHRJIMCPF5PXYIGYQ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QV2BY3ZWPPHRJIMCPF5PXYIGYQ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:QV2BY3ZWPPHRJIMCPF5PXYIGYQ","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":"f2b992c4dc8eabf89ac1d07c714bb6803e4b82ed17950b364c80343a0637e9d1","cross_cats_sorted":["eess.SP","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2021-06-22T16:04:34Z","title_canon_sha256":"fc8eaf09ceef162f3b6de7bf50830a02112c9575a774f7d1f8e26fc85c7627a0"},"schema_version":"1.0","source":{"id":"2106.11896","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2106.11896","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"arxiv_version","alias_value":"2106.11896v2","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2106.11896","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"pith_short_12","alias_value":"QV2BY3ZWPPHR","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"pith_short_16","alias_value":"QV2BY3ZWPPHRJIMC","created_at":"2026-07-05T03:05:02Z"},{"alias_kind":"pith_short_8","alias_value":"QV2BY3ZW","created_at":"2026-07-05T03:05:02Z"}],"graph_snapshots":[{"event_id":"sha256:4dabb6bfc9b465d84e411c6c73000fb7d2a6cca0fda0c1b09bfb1e4ad144da9f","target":"graph","created_at":"2026-07-05T03:05:02Z","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/2106.11896/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Intelligent reflecting surface (IRS) is an emerging technology to enhance the spectral and energy efficiency of wireless communications cost-effectively. This letter considers a new multi-IRS aided wireless network where a cascaded line-of-sight (LoS) link is established between the base station (BS) and a remote user by leveraging the multi-hop signal reflection of selected IRSs. As compared to the conventional single-/double-hop IRS system, multi-hop IRS system provides more pronounced path diversity and cooperative passive beamforming gains, especially in the environment with dense obstacle","authors_text":"Rui Zhang, Weidong Mei","cross_cats":["eess.SP","math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2021-06-22T16:04:34Z","title":"Distributed Beam Training for Intelligent Reflecting Surface Enabled Multi-Hop Routing"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2106.11896","kind":"arxiv","version":2},"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":"sha256:04f8aee5bbf1d44c16652e97e103c4cfb91a64159efdb8174a9078f9be08ee3b","target":"record","created_at":"2026-07-05T03:05:02Z","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":"f2b992c4dc8eabf89ac1d07c714bb6803e4b82ed17950b364c80343a0637e9d1","cross_cats_sorted":["eess.SP","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2021-06-22T16:04:34Z","title_canon_sha256":"fc8eaf09ceef162f3b6de7bf50830a02112c9575a774f7d1f8e26fc85c7627a0"},"schema_version":"1.0","source":{"id":"2106.11896","kind":"arxiv","version":2}},"canonical_sha256":"85741c6f367bcf14a182797afbe106c40fd97a083d2afeaf8c9184865b5b31ba","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"85741c6f367bcf14a182797afbe106c40fd97a083d2afeaf8c9184865b5b31ba","first_computed_at":"2026-07-05T03:05:02.936906Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T03:05:02.936906Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"3bI5+oXJ3NI8ykLBsIPkeB8y3xh5umY+NG4zTY9Hwt+o2mzr/isUqm40SHggcXQ+kD8JcBZBSw1BpJLn8en/BQ==","signature_status":"signed_v1","signed_at":"2026-07-05T03:05:02.937354Z","signed_message":"canonical_sha256_bytes"},"source_id":"2106.11896","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:04f8aee5bbf1d44c16652e97e103c4cfb91a64159efdb8174a9078f9be08ee3b","sha256:4dabb6bfc9b465d84e411c6c73000fb7d2a6cca0fda0c1b09bfb1e4ad144da9f"],"state_sha256":"17c27132454132c79cf00e80515a783be0ae8088498d53c290d864ef88fcef6d"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"/a+LK+XgGW/SqzIVrk/Qo8zuc57BBtXFPEVqsFxPUgTrn6vtRIo0eXVRpDAhbbxMxjP4puIJtY62qtG2kQbjCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-05T11:12:25.137392Z","bundle_sha256":"25f48683855819ca73994fb1b24d2d5ae94c849647cfe4c1a85b2dbb13e5aab1"}}