A model of smart city is seen at the 2025 Smart City Expo World Congress in Barcelona, Spain, Nov. 4, 2025. The event will last till Nov. 6. (Photo by Joan Gosa/Xinhua)
This photo taken on Nov. 4, 2025 shows a scene at the 2025 Smart City Expo World Congress in Barcelona, Spain. The event will last till Nov. 6. (Photo by Joan Gosa/Xinhua)
A robotic dog is seen at the 2025 Smart City Expo World Congress in Barcelona, Spain, Nov. 4, 2025. The event will last till Nov. 6. (Photo by Joan Gosa/Xinhua)
A drone is seen at the 2025 Smart City Expo World Congress in Barcelona, Spain, Nov. 4, 2025. The event will last till Nov. 6. (Photo by Joan Gosa/Xinhua)
An electric vehicle is seen at the 2025 Smart City Expo World Congress in Barcelona, Spain, Nov. 4, 2025. The event will last till Nov. 6. (Photo by Joan Gosa/Xinhua)
This photo taken on Nov. 4, 2025 shows a scene at the 2025 Smart City Expo World Congress in Barcelona, Spain. The event will last till Nov. 6. (Photo by Joan Gosa/Xinhua)
A robotic dog is seen at the 2025 Smart City Expo World Congress in Barcelona, Spain, Nov. 4, 2025. The event will last till Nov. 6. (Photo by Joan Gosa/Xinhua)