Amazon.com Inc. said on Wednesday it is developing a longer-range equivalent to Bluetooth and Wi-Fi wireless protocols that the largest U.S. online retailer hopes third parties will eventually use in smart devices.

The Amazon Sidewalk, announced alongside a new range of Echo speakers and a multilingual mode for its Alexa virtual assistant, underscores the firm's growth expectations for the internet of things — where a wider variety of devices and appliances are controlled over computer networks.

The company anticipates Sidewalk's use in devices as varied as garden water sensors, and mailboxes that would alert the owner to new mail.