Future Mobile Phone Technology

What are Wi-Fi phones? Wi-Fi phones are cordless phones that connect to Wi-Fi hotspots in order to communicate. Wi-Fi is a technology to transmit data at high speeds wirelessly. Wi-Fi phones use the same technology used in VoIP (Voice over Internet Protocol). VoIP is a new technology that allows users to make long distance calls for free, but there is a limitation that the call must come from a computer. These new Wi-Fi phones make it possible to use the VoIP to call without being connected to a computer. They use same wireless network technology that computers use. Wi-Fi phones can call to a computer, another cellular device, landline phone or to VoIP address.

Wi-Fi phones are a part of Smartphone. Smartphones are hand held phones that have pc like features. A usual Smartphone would come with GPS, email and eBooks capabilities. Smartphones also have options of installing and external application to satisfy your growing needs. Here is a summary of features that a Smartphone is capable of performing:

Send and receive phone calls.
Managing personal information like contacts and appointments.
Connecting and communicating with other devices like a PC, laptop or a Smartphone itself.
E-mail and instant messaging.
Office applications like word and pdf.
Capture and play audio and video in standardized formats.

Smart-phones have a high processing speed in the range of 200 to 700 MHz The smartphones uses ARM processor. These processors are highly power efficient and are used in printers, mp3 players and other small devices. They have a built in memory plus an expansion slot for extra storage. The software of a Smartphone can be visualized in layers as follows:

Kernel: It is the heart of the software; it manages all the software processes and drivers.
Middleware: It consists of all the software libraries and APIs required for application execution.
User interface layout: The GUI and layouts are present here.
Applications: Here is where the applications are stored and ready to be executed.

Every phone has an Operating System (OS). The OS of a Smartphone controls the functions and enables the interaction of the hardware with the software. A Wi-Fi phone initially connects to the Wi-Fi hotspot, based on the connection it check for VoIP capabilities and places a VoIP call on user’s request. Just like a pc, packets of data are exchanged between the router and the phone during a phone call. From a hardware point of view, wireless phones transmit signals at a different frequency. The general phones transmit at 850 MHz whereas the wireless phones use the Wi-Fi 802.11b or 802.11g signals that transmit at 2.5 GHz. In a Wi-Fi phone, as the number is entered it is converted into packets and sent to the wireless receiver. The wireless receiver sends the call to the internet like any other VoIP call. When the conversation is started the voice is also transmitted in packets. Some Wi-Fi phones use a Session Initiation Protocol (SIP) protocol. Calls can be made by just entering the desired SIP address. SIP is one of the standard protocols for handling voice data. Currently Wi-Fi phones do not have a lot of potential due to lack of Wi-Fi routers all around the country. So it is not necessary that everyone who has a Wi-Fi phone has a wireless connectivity in order to receive calls. Some Wi-Fi phones come with a GSM feature hence the user can receive calls with or without a Wi-Fi connection. VoIP uses a lot of bandwidth, if the router gets too crowded then loss in quality will occur, such problems prevent the current growth of Wi-Fi phones.