A USER-CENTERED TECHNICAL REQUIREMENTS FRAMEWORK FOR RELIABLE BEIDOU-BASED CONSUMER NAVIGATION IN CHINESE MEGA-CITIES

Abstract

Chinese mega-cities such as Shanghai, Shenzhen, Beijing, and Guangzhou create difficult conditions for consumer-grade BeiDou Navigation Satellite System receivers. In dense urban areas, tall buildings, elevated roads, glass facades, and narrow street canyons often cause multipath interference and non-line-of-sight signal reception. These effects reduce positioning accuracy and make it difficult to meet the 5–10 meter accuracy usually needed for ride-hailing, food delivery, pedestrian navigation, and other consumer map services. Although BDS-3 provides global coverage and supports several open-service signals, including B1I, B1C, B2I, B2a, and B3I, many consumer implementations still do not include clear requirements for handling multipath and NLOS errors in urban environments. This paper proposes a set of user-side technical requirements for BeiDou-based consumer navigation applications in Chinese mega-cities. Rather than focusing on system-level signal specifications, the proposed requirements are aimed at consumer receivers, positioning algorithms, and application-layer fallback strategies. The main requirements include a minimum satellite elevation mask of 15° in urban canyon environments, mandatory use of B1C/B2a dual-frequency observations to reduce multipath effects, stationary position oscillation of no more than 2 m at traffic lights, NLOS detection probability of at least 90%, and map-matching fallback when horizontal uncertainty remains above 10 m for 3 seconds or longer. The paper also recommends at least six visible satellites for a reliable 3D fix, including two BDS-3 GEO or IGSO satellites, a maximum cold-start Time-To-First-Fix of 30 seconds in standalone mode or 5 seconds in assisted mode, and 3D city model aiding for high-reliability use cases. Verification methods are also proposed for each requirement, including field testing in representative urban canyon environments and simulation-based analysis of multipath scenarios. The requirements are based on published research on urban GNSS multipath, BDS Interface Control Documents, and practical navigation challenges observed in Chinese mega-cities. Overall, these specifications provide a practical technical framework for consumer application developers, smartphone chipset manufacturers, and urban planners. The paper also highlights current implementation gaps, especially the limited use of consumer-grade NLOS detection and 3D aiding, as important directions for future BDS receiver development.