The update lets iPhone, iPod Touch, Apple Watch and Mac users make and receive calls from multiple devices using a single phone number.
Users of the latest iPhones, including the 6s and 6s Plus, will now be able to fully use Sprint's enhanced WiFi calling services to share one number among multiple Apple devices once they update their equipment with Apple's latest iOS 9.1 operating system.
Back in April, Sprint unveiled WiFi calling capabilities for customers with iPhone 6, iPhone 6 Plus, iPhone 5c and iPhone 5s smartphones, but the latest iOS 9.1 update offers the capabilities to more iPhone models and adds the shared-number capability, according to Sprint. WiFi calling lets users make phone calls over WiFi when normal cellular connections are weak or not possible, which vastly extends the range and service of the devices.
On Oct. 21, Sprint announced the expanded WiFi calling options, which will now let customers get an incoming phone call on one device and take the call on another device, whether it is their iPad, iPod Touch, Apple Watch or Mac computer.
"Customers already enjoy seamlessly responding to texts and email from a variety of great Apple devices," David Owens, senior vice president of product development at Sprint, said in a statement. "Now they can bring that flexibility to the primary phone number their friends, family and colleagues know best. This great feature puts the power of device choice in our customers' hands."
To use the new enhanced one-number capability
, customers must update their Apple mobile devices that run iOS to the latest iOS 9.1 version, and then ensure that they are running the latest Apple operating system software on their Apple Watch, MacBook and Mac computers, according to Sprint. The latest iOS 9.1 update will bring the enhanced WiFi calling services to iPhone 6s, iPhone 6s Plus, iPhone 6, iPhone 6 Plus, iPhone 5s and iPhone 5c devices.
Once the update is downloaded and installed, the devices must then use the same Apple ID and be signed into Apple's iCloud to enable the new capabilities. WiFi Calling must also be enabled on the primary device, the iPhone, through Settings, Phone and WiFi Calling.
Secondary devices must then be set up through the settings menu at Settings, FaceTime and Calls from the iPhone menu.
WiFi calling services are provided for free as part of Sprint's calling plans and can be used anywhere there is WiFi. Data used over WiFi networks also does not count against a customer's calling plan, according to Sprint.
Sprint originally began offering WiFi calling services to many of its Android customers in February 2014, but Apple iPhone users were left out at that time and didn't have access to the fledgling WiFi calling capabilities. WiFi calls are free to any phone number in the United States, the U.S. Virgin Islands or Puerto Rico.
In addition, the free WiFi calling feature is available to Sprint customers when they are traveling internationally in more than 200 countries, giving them the ability to call home for free on their devices as long as they are using a WiFi connection.
WiFi smartphone capabilities have been expanding in the last year, with competitor T-Mobile unveiling similar services in September 2014 for its customers, according to an earlier eWEEK
report. The T-Mobile offering was part of the company's WiFi Unleashed initiative, which gave its customers the ability to make mobile calls using WiFi networks almost anywhere around the world and to get free texting, messaging and voice mail services on domestic airline flights that are served by Gogo.
AT&T rolled out WiFi calling for iPhone 6s and iPhone 6 smartphones running iOS 9 earlier in October after receiving a waiver from the Federal Communications Commission for rules that require accommodations for hearing-impaired customers who rely on TTY services.
The waiver, issued Oct. 6, was required because teletypewriter (TTY) services don't operate properly over WiFi networks. TTY services under FCC rules must be provided for telecommunications networks.
TTY services allow voice communication to be relayed using typed words, rather than by voice. AT&T customers use their existing mobile phone numbers and are able to make and receive calls as they normally would on the cellular network. No separate app or configuration is needed. There are no additional costs for the service for calls to U.S. phone numbers.