Abstract: An alarm sensor can be located at a premises, for example a smoke detector mounted to a wall or ceiling of a building. In response to an alarm event, such as detection of a level of smoke indicative of a fire hazard, the alarm sensor can send a wireless notification directly to a remote recipient that is offsite from the premises. The recipient could be a smart phone or other handheld cellular device carried by a homeowner on vacation, for example. The alarm sensor can be either originally manufactured with remote notification capabilities or retrofitted after installation for remote notification. In some cases, the alarm sensor can be networked with other alarm sensors located at the premises. For example, an alarm sensor having remote notification capabilities can receive alarm notifications from other alarm sensors for relay to the remote recipient.