Proposal of an Information Delivery Method for Electronic Paper Signage Using Human Mobility as the Communication Medium Hokkaido Information University Takafumi Akiba and Tsubasa Yumura 

Introduction | Digital Signage • Digital Signage • Signage that leverages digital technology • Displays information such as advertisements in the form of images and videos 2 Digital Signage Market 2023- Size, Share, Trends, Statistics, Top Leaders, & Research Report 2028 - Industry Today https://industrytoday.co.uk/market-research-industry-today/digital-signage- market-2023-size-share-trends-statistics-top-leaders-research-report-2028 • Electronic Paper Signage (EPS) • Digital signage employing electronic paper technology • Electronic paper consumes power only when updating the display E-paper E-link Solar Powered 13.3inch Display | AVLink Digital Signage https://www.lcdhome.live/product/e-paper-e- link-solar-powered-13-3inch-display/ ePaper Digital Signage: Technology and Sustainability https://castitsignage.com/digital-signage- hardware/epaper-digital-signage 

Introduction | EPS Update Method 3 Manual Local Update • Administrators directly transfer data using SD cards or USB drives • It is not suitable for large-scale deployment Online Update • Remotely update content on the device • Using Wi-Fi and cellular networks such as LTE and 5G • It requires waiting for the content to be received • Updating EPS requires communication infrastructure 

Introduction | Previous Studies Akiba and Yumura (2025)，NNEPS: A Power-efficient e-Paper Signage System with Remote Content Updates • In EPS, the control computer consumes power during communication standby, resulting in unnecessary power consumption • A normally-off design for EPS is proposed • Power consumption was reduced by about 33% compared with the conventional method 4 Normally-off: The device is normally off and activates only when needed. 

Introduction | Utilization of low-power EPS • Information display in mountain regions without established power or communication infrastructure • Providing information and safety notices using paper displays • Patrols by local governments and conservation groups for poster replacement : The update cost is high • Frequent updates like those on websites are not possible. 5 • Expectations for EPS as a replacement for paper media • Operable with standalone power sources such as solar power • The establishment of communication infrastructure present challenges New Trail Signs Meant to Improve Weather Safety in the White Mountains - Mount Washington Observatory https://mountwashington.org/new-trail-signs-meant-to- improve-weather-safety-in-the-white-mountains/ Trip Report: Hiking Up the Steep Slopes of North Twin Mountain – Protean Wanderer https://www.proteanwanderer.com/2021/01/22/t rip-report-hiking-up-the-steep-slopes-of-north- twin-mountain/ 

Problem and Research Objectives Problem • Frequent information updates on EPS require Internet-based communication • In mountainous areas where communication infrastructure cannot be established, it is difficult to install network-update-type EPS • A method is needed to deliver necessary information to EPS without relying on communication infrastructure 6 EPS Update Method Independent of the Communication Infrastructure Research Objectives 

Proposal Method • Delivering EPS update data via devices carried by people 7 Received Send Moving 

Related Work 8 • Lu et al. (2017)，TeamPhone: Networking Smartphones for Disaster Recovery • TeamPhone, which enables smartphones to form an ad-hoc communication network during disasters, was proposed • Achieving Distributed Communication Maintenance under Power Constraints • Pentland et al. (2004)，DakNet: Rethinking Connectivity in Developing Nations • The asynchronous network “DakNet,” which enables buses and other vehicles to transmit data, has been demonstrated for use in developing regions. Research Novelty • This research enables bidirectional updates between fixed nodes via BLE proximity communication • This research enables on-demand activation of fixed nodes through proximity-driven method that leverage human mobility 

Mobile Terminal Proposal method | Protocol Design 9 • Mobile terminal： Smartphones, wearable devices, etc. • Bluetooth Low Energy (BLE) communication is performed when a mobile device approaches the EPS EPS • Delivering EPS update data via devices carried by people 

Protocol Design | BLE Connection 10 EPS Mobile Terminal 1. advertise 2. scan 3. BLE Connection Regular information dissemination ：advertise Receive surrounding information (scan) 

Protocol Design | Exchange Data Exchange Data Format • Send in JSON format 11 EPS Mobile Terminal Field Name Explanation version_id Data version identifier content Content Data timestamp Data Creation Time 1. Send Owned Data 4. Save 3. Send Newest Data 2. Update Process Version ID Comparison Case 1 : Same Data : No Update Case 2 : EPS data is outdated : EPS Content Update Case 3 : EPS data is new : Mobile Terminal Content Update 

Prototype | Technical Components 12 M5Paper v1.1 https://docs.m5stack.com/ja/core/m5paper_v1.1 Hardware • Mobile Terminal and EPS used M5Paper v1.1 • Touch-enabled E-Ink device • ESP32-D0WDQ6-V3 • Enables BLE communication Software • C++ • M5Unified：Terminal Control Library • esp_gap_ble_api：BLE Library Communication standard • Bluetooth Low Energy (BLE) • Low power consumption • Communication range up to 100 meters 

Prototype 13 

Summary 14 • Proposal and prototype implementation of a method to update EPS without using communication infrastructure • We have confirmed that basic functions such as communication processing and data synchronization are operating normally