VoIP enabled femtocell with a USB transceiver station
Telephone calls between a mobile station (MS) and the mobile network or PSTN are routed through the Internet via VoIP using a femtocell, as opposed to the traditional macrocellular network. The femtocell can comprise a USB Transceiver Station that is connected to a personal computer through a universal serial bus port, which provides both power and a multi-megabit per second connection between the personal computer and the USB transceiver station. The USB transceiver station can comprise a microcontroller to manage signaling between the RF front end/baseband processor and the personal computer, as well as a precise timing mechanism to assist the synchronization of femtocell timing with the surrounding macrocellular network, if it is present. The USB transceiver station can have a compact form factor that facilitates a high degree of portability by the subscriber, such as being readily attachable to their keychain.
1. A femtocell system for coupling mobile phone signals with voice over internet protocol messaging, having a processor for executing modules, the system comprising:
a voice over internet protocol client module for sending registration messages from the femtocell system and for maintaining a network address translation port bindings between a femtocell and a server, for receiving a User Datagram Protocol (UDP) packet containing a plurality of media frames from the server, for recording the media frames in a jitter buffer, for receiving a call request from the server via the network address translation port binding, and for using a UDP port number for transmitting and receiving media;
a software defined radio module for communicating with the voice over internet protocol client module, for processing and generating digital radio baseband signals, and for measuring received signal strength of digital radio based band signals in a predetermined frequency range;
a call-control processing module for receiving the call request and for translating the call request into a call-control message transmitted to a mobile phone; and
an access control database module within the femtocell for storing at least one of an International Mobile Subscriber Identity (IMSI) value and an International Mobile Equipment Identity (IMEI) transmitted by the mobile phone.
2. The femtocell system of claim 1 , further comprising a configuration file that comprises an allowed radio-frequency range for the femtocell system and an address of a voice over internet protocol server on the Internet.
3. The femtocell system of claim 1 , wherein the voice over internet protocol client monitors quality of an Internet connection.
4. The femtocell system of claim 1 , wherein the software defined radio disables radio communications if a quality of an Internet connection falls below a predetermined level.
5. The femtocell system of claim 1 , wherein the voice over internet protocol client manages a forward error correction on communications to compensate for packet loss related to an Internet connection.
6. The femtocell system of claim 1 , wherein an international mobile subscriber identity code and a femtocell are allocated a unique mobile network code to associate a mobile handset with a network of femtocells.