Femtocells use proprietary security, with a firewall that sits between the caller and the carrier.
Critics of Sprint's Airave have pointed out that the device ships "unlocked" to all Sprint customers -- in other words, anyone with a Sprint phone in range of your femtocell can use your connection. However, the company points out that in most cases, other users would have to be inside your home to be in range of the femtocell. You can also choose to restrict access to the service to up to 50 select phone numbers.
Whether other carriers will make their femtocell devices open to other customers by default remains to be seen.
Will my carrier offer femtocells soon?
Whether we'll see more US carriers join Sprint in offering femtocell service in 2009 remains unclear. Verizon Wireless is "exploring [femtocells'] use but have not committed to rollout plans yet," says Tom Pica, a company spokesman.
AT&T, the nation's largest wireless carrier, remains mum on its vision for femtocells. However, recent reports suggest that the carrier is asking suppliers to submit proposals for developing such a service. Additionally, AT&T is part owner of 2Wire, maker of DSL home gateways. 2Wire recently announced plans to make gateways with femtocell functionality.
If true, the reports wouldn't surprise In-Stat's Nogee, who says AT&T's entrance into femtocells is likely.
As for T-Mobile, although the international venture arm of the company has invested in femtocell manufacturer Ubiquisys, industry watchers say T-Mobile USA is sticking with its Hotspot@Home service , based on Wi-Fi rather than femtocell technology.