Comcast, the US's largest broadband provider, has announced plans to expand its public Wi-Fi network by turning millions of customers' cable modems into open wireless hotspots, as well as providing new wireless home automation capabilities.

As Comcast explained in a blog post on Monday, the newest version of its Xfinity Wireless Gateway automatically broadcasts two Wi-Fi signals – a private one for the customer and a second one for use by the public.

Traveling Comcast customers who encounter one of these public hotspots, which use the SSID "xfinitywifi," will be able to login using their Comcast usernames and passwords to gain internet access, just as they would at home.

The company says it has been testing the neighborhood Wi-Fi program in parts of New Jersey, Pennsylvania, Virginia, and Washington DC since last year and it's now ready to roll it out to the rest of its nearly 20 million customers.

The new hotspots will join the more than 150,000 public hotspots that Comcast customers can already access as part of the CableWiFi Alliance public Wi-Fi project.

Comcast has made further information on the Xfinity Wi-Fi project available on its website, including a searchable coverage map to help customers locate public hotspots in their area.

From May 24 through July 4, the Xfinity hotspots will be accessible by anyone for free as part of a limited trial. After that, they will only be available to Comcast subscribers.

Customers who would like to offer their own connections as public Xfinity hotspots will need to have the latest version of Comcast's Xfinity Wireless Gateway, which began rolling out in April. On Monday, Intel confirmed that the new hardware is based on Chipzilla's Puma 6 DOCSIS silicon and that it can achieve downstream speeds of up to 640Mbps.

In addition to the public Wi-Fi project, Comcast also said on Monday that it is expanding its Xfinity Home group of services to include home monitoring and automation.

For $99.95 and up, customers can purchase a "starter pack" of Xfinity Home Control wireless monitoring devices and manage them via an online service, starting at $9.95 per month. The devices allow customers to turn lights and thermostats on and off, receive notifications when doors or windows open and close, and monitor rooms via wireless video cameras.

A separate cloud-based service, dubbed EcoSaver, can monitor wireless Xfinity Home thermostats to learn the heating and cooling patterns of a home and then make automatic, incremental adjustments to the thermostats based on customer preferences and real-time local weather data.

"The home control market is growing tremendously, and it's being driven by innovative technology, affordability and consumer demand," said Comcast senior VP Mitch Bowling said in a statement. "With the launch of Xfinity Home Control, we're adding yet another way customers can remotely manage their homes anywhere and at anytime." ®