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«Seamless» Wi-Fi - is a model for broadcasting one WiFi network using a controller and dependent access points. Access points can be many, and control of their broadcasting is handled by one centralized device-controller.

Socket - is the name of a software interface for providing data exchange between processes. Processes with such an exchange can be performed both on one computer and on different computers connected by a network. A socket is an abstract object representing the endpoint of the connection. Concretely, it is a representation of this endpoint in networking software (protocol stack), such as an entry in a table (listing communication protocol, destination, status, etc.), and is a form of system resource.

INTRODUCTION

Communication systems have developed steadily and new means of communications are being developed from time to time. Cell phones have evolved from being simple communication devices to a powerful portable computer. The instrument has become so commercial that it’s available as a key-item in everyone’s pocket, benefitting the user and serving as a lucrative business for the manufacturers. The increase in the number of service providers has made it a battle-field for each of them to gain more customers, and the cheaper one always manages to outstrip others. Service providers such as Vodafone, Airtel, Loop have already earned a name in market and are still expanding their service all over the world. The idea of having a common channel (air) for sending innumerable frequencies and use the bandwidth that’s available has always been fascinating for all of us – but at what cost? It is a hectic task to design a communication system knowing how badly it is susceptible to noise.

Existing technologies like the GSM based calling provided by the service providers cost users to pay for the services they use. Moreover the rates for these services vary over time and this causes the customers with inconvenience. So to eliminate the users dependence on the service providers we present a solution to this by creation of an application which gives its users the facilities like free calling within a Wireless network, Text messaging, any type of data sharing and that too in real time.

EXISTING TECHNOLOGY

Voice over Internet Protocol (VOIP) provides the ideas for connecting two clients through voice over the internet. The advent of Voice over Internet Protocol (VoIP) has fundamentally been transforming the way telecommunication evolves. Driven by the ongoing deployment of broadband infrastructure and the increasing demand of telecommunication service, VoIP technologies and applications have led to the development of economical IP phone equipment based on embedded systems. IP phone application can satisfyingly provide the necessary interfaces between telephony signals and IP networks. Although IP phone communication over the data networks such as LAN exists but these IP phones are fixed type. We implement wireless IP phone communication using the Wi-Fi network, VOIP phones call without the use of a computer; instead they connect directly to the IP network (using technologies such as Wi-Fi or Ethernet).

Unlicensed Mobile Access (UMA) is a 3rd Generation Partnership Program global specification that provides a standard for service providers to merge mobile networks and wireless LANs into a single seamless access network with one mobile device, one user interface, and a common set of network services for both voice and data. In fact, the UMA solution converge cellular networks with any IP-based access networks, including wired and wireless technologies such as IEEE 802.16 WiMAX networks, IEEE 802.20 Mobile Broadband Wireless Access, and Ultra Wideband (UWB)- based networks (Fig. 1).

Fig. 1. UMA connection mode.

With UMA, subscribers can move between mobile networks and WLANs with seamless voice and data session continuity as effortlessly and transparently as they move between cells within the mobile network. The UMA solution effectively creates a parallel radio access network, the UMA Network (UMAN), which interfaces to the mobile core network using existing mobility-enabled, standards-defined interfaces. The existing service provider Business Support Systems (BSS), service delivery systems, content services, regulatory compliance systems, and Operation Support Systems (OSS) will support the UMA network without change. Service enhancements and technology evolution of the mobile core network apply transparently to both the GSM access network and the UMA network.

CALLING WITHIN THE NETWORK

For a mobile device to communicate with a router it needs a platform. An Android application can be used in a mobile device that is Wi-Fi enabled to communicate with a router. This is a very useful tool because by communicating with the router directly, many processes of networking can be simplified. Android provides a robust, flexible environment for applications running on mobile. It includes flexible user interfaces, robust security, built-in network protocols, and support for networked and offline applications that can be downloaded dynamically. So this platform is what connects the user and his device to the server running on another laptop connected to the same network. The application will record the voice from the transmitter side and store it in a buffer and this data stored in the buffer will be received at the receiver’s side.

For placing a call to any person X a user needs to ensure that the person X is connected to the network and registered on the server running on the laptop. The user will request the server to send the IP of the person X which on receiving a request will reply with an IP (if available). On receiving the IP the caller device will create a socket and

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