Until recently, voice over IP (VoIP) had one pretty big limitation — to make a call, you had to be at a computer. New phones make it possible for people to place VoIP calls without being leashed to a computer. WIFI phones use the same wireless network technology that computers use, making VoIP a lot more portable.
Packet Switching and VoIP
VoIP uses packet switching rather than circuit switching. Instead of leaving an entire circuit open during the whole conversation, it breaks the conversation into small packets of data. It then transmits that data over the Internet. Instead of monopolizing a circuit, packet switching sends and receives data as needed.
WIFI phones – detail.
WIFI phones use different frequencies than cellular phones do. WIFI phones use the 802.11b or 802.11g standards transmit at 2.4 GHz. Phones that use the 802.11a standard transmit at 5 GHz.
When you make a call on a WIFI phone, you dial the number of the person you want to cal. If you’re calling another VoIP user, you may enter a VoIP address instead of a phone number, depending on the service provider’s requirements.
The phone translates the number you dial into packets of data. It uses radio waves to transmit the packets to a wireless receiver. The receiver passes the information over the Internet to the call processor like an ordinary VoIP call. When you begin your conversation, the phone transmits your voice in packets of data as well.
Many of these phones use a specific WiFi service or network. SIP is an open protocol. Anyone can use it, and anyone who has a SIP address can contact anyone else who has one for free.
Eventually, SIP will probably make communications tools interoperable. In other words, your computer, phone and other communications tools could all share the same address book and communicate with one another.
For more information call Ryan Danvers on 072 601 2858.