[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-83388-en":3,"doc-seo-83388-105":30,"detail-sidebar-cat-0-en-105":91},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":20,"is_deleted":4,"is_public":21,"is_downloadable":21,"audit_status":21,"page_count":22,"language":23,"language_code":24,"site_id":25,"html_lang":24,"table_of_contents":26,"faqs":27,"seo_title":13,"seo_description":14,"update_tm":28,"read_time":29},83388,13056703020460,"Valentina","https://ap-avatar.wpscdn.com/avatar/be000253dac470eee5d?_k=1778207105932848923",8,"Research & Report","Early to Share, Late to Save Synchronisation-Driven Communication Gating in Bandwidth-Constrained Cooperative VLN","Most cooperative Vision-Language Navigation (VLN) work assumes unlimited communication, while real deployments face strict bandwidth limits that require information-efficient coordination. The paper introduces bandwidth-constrained cooperative VLN and a hindsight gating method: a lightweight supervised gate trained post-hoc from navigation failures to avoid REINFORCE’s high variance. Results show counterintuitive behavior—gates activate mainly in early steps, even when agents are confident—explained by recurrent hidden-state synchronization.","arXiv :2607 .08504v 1 [ cs .MA] 9 Jul 2026  \nEarly to Share, Late to Save: Synchronisation-Driven Communication Gating in Bandwidth-Constrained Cooperative VLN  \nArav Gupta⋆ , Nivedan Yakolli, and Avinash Gautam  \nBirla Institute of Technology and Science, Pilani Campus, Pilani, Rajasthan 333031,  \nIndia  \n[f20231280@pilani.bits-pilani.ac.in](f20231280@pilani.bits-pilani.ac.in)  \n[p20230032@pilani.bits-pilani.ac.in](p20230032@pilani.bits-pilani.ac.in)  \n[avinash@pilani.bits-pilani.ac.in](avinash@pilani.bits-pilani.ac.in)  \nAbstract. Most cooperative Vision-Language Navigation (VLN) methods assume unlimited communication, not considering real-world applications where bandwidth is restricted and information efficiency is critical. We introduce bandwidth-constrained cooperative VLN and propose hindsight gating: a lightweight supervised gate that labels communication-critical steps post-hoc from navigation failures, avoiding the high variance of REINFORCE. Contrary to the intuition that agents should communicate when uncertain, we observe a consistent counterintuitive pattern: trained gates fire predominantly in early episode steps and more often when agents are confident, across all budget levels (B ∈{1, 3 , 5}) . We explain this through recurrent hidden-state alignment:  \nearly communication injects grounded trajectory representations that persist and compound through subsequent Gated Recurrent Unit (GRU) updates, achieving +0 .072 cumulative alignment gain with B=3 transmissions, approaching unconstrained communication (+0 .078) at 260% greater alignment efficiency than random gating (+0 .020) and 320% greater efficiency than entropy-based gating (+0 .017) . Our results establish a new communication regime for bandwidth-limited embodied agents: synchronise representations early, navigate independently later.  \nOur codebase is available at: [https://github.com/AravG13/bandwidth](https://github.com/AravG13/bandwidth)  \n[-constrained-cooperative-vln](-constrained-cooperative-vln.)[.](-constrained-cooperative-vln.)  \nKeywords: Vision-Language Navigation · Multi-Agent Communication  \n· Bandwidth-Constrained Communication · Recurrent Neural Networks  \n· Hindsight Supervision.  \n1 Introduction  \nVision-Language Navigation (VLN) requires an embodied agent to follow natural language instructions through photorealistic indoor environments [1] . Real-world deployments such as search-and-rescue, warehouse automation, and multi-drone  \n⋆ Corresponding author: [f20231280@pilani.bits-pilani.ac.in](f20231280@pilani.bits-pilani.ac.in)  \n2 A. Gupta et al.  \ninspection naturally involve multiple coordinated robots sharing a building anda goal. Extending VLN to this cooperative setting introduces a fundamental engineering constraint: radio channels, mesh networks, and privacy-constrained systems all impose hard limits on how often agents can communicate.  \nYet existing cooperative navigation methods [10, 15, 16] assume agents share observations freely at every step. This makes the when of communication – which steps are worth a transmission under a tight budget – an open problem for language-guided navigation. The challenge is compounded by a training difficulty: prior methods [11, 14] learn communication gates with REINFORCE, which suffers from high variance because the causal link between a single gate decision at step t and episode success 15–20 steps later is long and noisy.  \nWe address both challenges. First, we propose hindsight gating: rather than learning which steps to communicate through trial-and-error policy gradients, we run agents without communication, observe where each agent failed while its partner succeeded, and use those observations as direct Binary Cross-Entropy (BCE) supervision for a lightweight gate. This converts a high-variance policy gradient problem into a stable supervised classification problem with zero reward variance.  \nStudying what the trained gate learns reveals a surprising finding. Rather than firing when ag","cbCaigZm4ESBzQWe","https://ap.wps.com/l/cbCaigZm4ESBzQWe","pdf",412643,3,1,12,"English","en",105,"# Introduction\n# Related Work\n# Problem Formulation\n# Hindsight Gating\n# Experiments and Analysis\n# Implications and Limitations","[{\"question\":\"What problem does the paper address in cooperative VLN?\",\"answer\":\"It addresses cooperative VLN under bandwidth-constrained communication, where agents cannot freely exchange information at every step due to practical channel and privacy limitations.\"},{\"question\":\"How does hindsight gating train the communication policy?\",\"answer\":\"Agents run without communication; where one agent fails while the partner succeeds, those observations become binary cross-entropy supervision to train a lightweight gate, avoiding the high-variance REINFORCE signal.\"},{\"question\":\"Why does the trained gate communicate mostly in early episode steps?\",\"answer\":\"The paper attributes this to hidden-state alignment: early communication injects grounded trajectory representations into GRU hidden states, which then propagate and compound through later recurrent updates even after communication stops.\"}]",1784187146,30,{"code":4,"msg":31,"data":32},"ok",{"site_id":25,"language":24,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":86,"head_meta":88,"extra_data":90,"updated_unix":28},"early-to-share-late-to-save-synchronisation-driven-communication-gating-in-bandwidth-constrained-cooperative-vln","",{"@graph":36,"@context":85},[37,53,68],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,48,50],{"item":41,"name":42,"@type":43,"position":21},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":47},"https://docshare.wps.com/document/","Document",2,{"item":49,"name":12,"@type":43,"position":20},"https://docshare.wps.com/document/research-report/",{"item":51,"name":13,"@type":43,"position":52},"https://docshare.wps.com/document/early-to-share-late-to-save-synchronisation-driven-communication-gating-in-bandwidth-constrained-cooperative-vln/83388/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":24,"description":14,"dateModified":61,"datePublished":62,"encodingFormat":60,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":41,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-25","2026-07-16",true,{"@type":65,"interactionType":66,"userInteractionCount":20},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71,77,81],{"name":72,"@type":73,"acceptedAnswer":74},"What problem does the paper address in cooperative VLN?","Question",{"text":75,"@type":76},"It addresses cooperative VLN under bandwidth-constrained communication, where agents cannot freely exchange information at every step due to practical channel and privacy limitations.","Answer",{"name":78,"@type":73,"acceptedAnswer":79},"How does hindsight gating train the communication policy?",{"text":80,"@type":76},"Agents run without communication; where one agent fails while the partner succeeds, those observations become binary cross-entropy supervision to train a lightweight gate, avoiding the high-variance REINFORCE signal.",{"name":82,"@type":73,"acceptedAnswer":83},"Why does the trained gate communicate mostly in early episode steps?",{"text":84,"@type":76},"The paper attributes this to hidden-state alignment: early communication injects grounded trajectory representations into GRU hidden states, which then propagate and compound through later recurrent updates even after communication stops.","https://schema.org",{"og:url":51,"og:type":87,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":89,"canonical":51},"index,follow",{"doc_id":7,"site_id":25},{"code":4,"msg":5,"data":92},[93,97,101,105,110,115,120,122,127,130,134],{"id":21,"doc_module":4,"doc_module_name":46,"category_name":94,"show_sort_weight":95,"slug":96},"Story & Novel",90,"story-novel",{"id":47,"doc_module":4,"doc_module_name":46,"category_name":98,"show_sort_weight":99,"slug":100},"Literature",80,"literature",{"id":52,"doc_module":4,"doc_module_name":46,"category_name":102,"show_sort_weight":103,"slug":104},"Exam",70,"exam",{"id":106,"doc_module":4,"doc_module_name":46,"category_name":107,"show_sort_weight":108,"slug":109},5,"Comic",60,"comic",{"id":111,"doc_module":4,"doc_module_name":46,"category_name":112,"show_sort_weight":113,"slug":114},6,"Technology",50,"technology",{"id":116,"doc_module":4,"doc_module_name":46,"category_name":117,"show_sort_weight":118,"slug":119},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":46,"category_name":12,"show_sort_weight":29,"slug":121},"research-report",{"id":123,"doc_module":4,"doc_module_name":46,"category_name":124,"show_sort_weight":125,"slug":126},9,"Religion & Spirituality",20,"religion-spirituality",{"id":125,"doc_module":4,"doc_module_name":46,"category_name":128,"show_sort_weight":125,"slug":129},"World Cup","world-cup",{"id":131,"doc_module":4,"doc_module_name":46,"category_name":132,"show_sort_weight":131,"slug":133},10,"Lifestyle","lifestyle",{"id":135,"doc_module":4,"doc_module_name":46,"category_name":136,"show_sort_weight":106,"slug":137},19,"General","general"]