Mobile VoIP: Extending Mobile Devices to Utilize VoIP Services
There are many ways to integrate a mobile handset into a VoIP network. One way to achieve a Mobile VoIP, or mVoIP, is to turn a mobile device into a SIP client. Once a mobile device becomes a SIP client it can easily send and receive Real Time Transport Protocol (RTP) & Session Initiation Protocol (SIP) messages through the data network. However, turning a mobile device into a SIP client requires that the device to be able to support a high speed Internet connection so the device can communicate with IP networks. WiFi, WiMAX, EVDDO rev A, or HSDPA, are broadband connections that allow a mobile device to connect to an IP capable wireless network needed that support the standard VoIP protocols (mainly SIP).
Using
softswitch vendors as a gateway to bridge the connection between mobile devices and the internet is another way to achieve mobile integration of a VoIP network. A softswitch codes the human voice into SIP and RTP protocols and send them into the SS7 infrastructure, allowing the mobile network to communicate with the VoIP network. This method gives GSM and CDMA based devices the ability to utilize advanced SIP based services by employing the use of a softswitch to allow mobile devices to communicate with SIP networks. Mobile devices can now communicated with any designated server that has SIP application software installed into to use SIP services.
The Mobile VoIP Networks
Mobile VoIP allows for calls to be made over the VoIP network using a mobile device. Depending on the network, the rate and quality of the calls are much better than traditional land line phone calls. Voice over WiFi is potentially free but only available in areas with WiFi access. It also does not offer quality calls as the connection is not secure or fast. Calls made over a WiFi network can be choppy and the user might experience lag time which can degrade the overall experience of using VoIP. For a more pleasant experience, using EVDO rev A or HSDPA high speed services available to mobile operators gives better audio quality and a wider range of coverage. With fast handoffs among the different mobile base stations, it cost more than a WiFi VoIP service but the quality of the call is significantly better.