英語(yǔ)翻譯
A simple civilian GPS receiver costs around $100 and represents the incremental cost of making a new object positionable independently of its global location.A system that uses infrared beacons for broad-casting room IDs requires a beacon for every room in which users want the system to fi\x0cnd them.In this case,both the infrastructure and the object the system locates contribute to the incremental cost.