Design And Implementation Of Wireless Voice Over Internet Protocol

Project and Seminar Material for Computer Science and Computer Engineering

Abstract

Voice over internet protocol (Vo/P) is a form of voice communication that uses audio data to transmit voice signals to the end user Vo/P is one of the most important technologies in the world of communication. Around, 20 years of research on Vo/P, some problems of Vo/P are still remaining. During the past decade and with growing wireless technologies we have seen that many project turn their concentration from wired – LAN to wireless LAN. Vo/P over wireless LAN (WLAN) faces many challenges due to the loose nature of wireless network. Issues like providing quality of service (QOS) at a good level, dedicating capacity for calls and having secure calls is more difficult rather than (VOWLAN) remains a challenging research topic, in this project we consolidate and address major (VOWLAN) issues. This write-up is helpful for those researcher that want to do research in voice IP technology over WLAN network.

Chapter One

1.0 Introduction

Voice over internet protocol (Voice Over/P, Vo/P) is a family of technologies, methodologies, communication protocols, and transmission techniques for the delivery of voice communications multimedia sessions over internet protocol (IP) networks, such as the internet. Other terms frequently encountered and often used synonymously with Vo/P are (P telephony. Internet telephony, Voice over broad band (VOBB), broadband telephony, and broadband phone.

Content telephone refers to communication services-voice, fax SMS and/or voice-messaging application – That are transported via the internet, rather than the public switched telephone network (PSTN). The steps involved in originating a VoIP telephone call are signiating and media channel setup, digitization of the analogy voice signal, encoding packitization, and transmission as internet protocol (IP) packet over a packet switched network on the receiving side, similar steps (usually in the reverse order such as reception of the IP packets, decoding of the packets and digital-to-analog conversion reproduce the original voice stream. Even through IP Telephony and VOIP are terms that are used interchangeable, they are actually different IP telephone has to do with digital telephony system that use IP protocol for voice communication while VoIP is actually a subset of IP Telephony. VoIP is a technology used by IP Telephony as a means of transporting phone calls.

VoIP systems employ session control protocols to control the setup and tear – down of calls as well as audio codes which encode speech allowing transmission over an IP network as digital audio via an audio stream. The codecs used is varied between different implementations of VoIP (and often a range of codecs are used). Some implementation rely on narrowband and compressed speech, which others support high fidelity stereo codecs.
VoIP is available on many smartphones and internet devices so event the users of portable devices that are not phones can still make calls or send SMS text messages over 3G or Wi-Fi.

VOWLAN (Voice Over Wireless LAN) is the use of a wireless broadband network according to the IEEE 802.11 standards for the purpose of vocal conversation. In essence, its VoIP over a Wi-Fi network. In most cases the Wi-Fi network and voice components supporting the voice system are privately owned.

VOWLAN can be conducted over any internet accessible device, including a laptop. PDA or the new VOWLAN units which look and function like DECT and cell phones. Just like for IP-DECT, the VOWLAN’S main advantages to consumers are cheaper local and international calls, free calls to other VOWLAN units and a simplified intergrated billing of both phone and internet service providers.

Although, VOWLAN and 3G have certain feature similarities, VOWLAN is different in the sense that it uses a wireless internet network (typically 802.11) rather than a cellular. Both VOWLAN and 3G are used in different ways, although with a femtocel the two can deliver similar service to users and can be considered alternatives.
A company with fixed warehouses or location would take advantage of their existing W-Fi network and use VoIP (hence VOWLAN) for employees to communicate with one another. This system can also be used like land mobile Radio system or walkie-talkie system with push to talk and emergency broadcast channels.

Another example would be a company that has mobile workers very much like the fedEX delivery person or the coca cola delivery driver who delivers goods to a store. These workers need to take advantage of 3G type service whereby a cellular company (Like cingular, verizon, T-mobile sprint/Nextel) provide data access between the hand held device and the companies back-end network.

1.1 Background of Study

Nokia corporation is a finish multinational communication corporation that is headquartered in Keilaniem Espoo, a city neighbouring Helsinki. http://en.wikipedia.org/wiki/Nokia-cite_note-2 Nokia manufactures mobile devices and related internet and communications industries with over 123,000 employees in 120 countries, sale in more than 150 countries and global annual revenue of EUR 41 billion and operation profit of EI.2 billion as of 2009 in it is the world’s largest manufacturer of mobile telephone. Its global device market share was 30% in the third qurter of 201, down from an estimated 34% in the third quarter 2009 and an estimated 33% in the second quarter 2010. Nokias estimated 38% in the third quarter, compared with 41% in the second quarter 2010. Nokia produces mobile devices for every major market segment and protocol, including GSM, CDMAS, and WCDMA (UMTS). Nokia offers viternet services such as applications, games, music, maps, media and messaging through its OVI platform. Nokia’s subsidiary Nokia siemens Network produces telecommunications network equipment, solutions’ and services. Nokia is also engage in providing free digital map in formation and navigation services through its wholly-owned subsidiary Navteq.

Nokia has sites for research and development manufacture and sales in many countries throughout the world. As of December 2009, Nokia had R&D presence in 16 countries and employed 37,020 people in research and development, representing approximately 30% of the group’s total workforce. The Nokia Research centre, founded in 1986, is Nokia’s industrial research unit consisting of about 500 researchers, engineers and scientists.

1.2 Statement of the Problem

Telephones for traditional residential analog service are usually connected directly to telephone company phone lines which provides direct current to power most basic analog handsets in dependently of locally available power.
IP phones and VoIP telephone adapters connect to routers or cable moderns which typically depend on the availability of mains electricity or locally generated power. Some VoIP service providers use customer premise equipment (e.g Cable modems) with batterey-backed power supplies to assure uninterrupted service for up to several hours in case of local power failure. Such battery-backed devices typically are designed for use with analogy handsets.

Some VoIP service providers implement services to route calls to other telephone services of the subscriber, such a cellular phone, in the event that the customer’s network device is in accessible to terminate the call. The susceptibility of phone service to power failures is a common problem even with traditional analog service in areas where many customers purchases modern telephone units that operate with wireless handsets to a base station, or that have other modern phone features, such as built voicemail or phone book features.

1.3 Purpose of Study

A voice over WLAN system offers tremendous benefits to organizations, such as hospitals and warehouses. The primary benefits and mobility and cost savings. For example. Nurses and doctors within a hospital can maintain voice communications at any time at less lost as a compared to cellular service. In most cases, it’s possible to receive a return on investment within three years.

1.4 Aim and Objectives

The primary aim of this project work is to provide lasting solution to the problem by computerizing the maintenance of record of NOKIA users to help track down user’s services and follow up provision of wireless voice overIP. To eliminate inadequate wireless voice over IP> also to make sure that the available wireless voice over IP are distributed equitable. The record is made easy access monitor the people wireless voice over IP are available for effective update and communication.

1.5 Significance of Study

The need for a study of this nature can not be over emphasized. It is expected that with the designed system, one can realize some important effects of the computerized wireless voice over IP. Some of the effects are:

Sharing of massive amounts of data
Supporting thousands of collaborators world-wide
Distributed data processing
Distributed simulation, visualization and computational steering.

1.6 Scope of the Study

The research is limited to wireless voice over IP as it is maintained with NOKIA corporation. It critically studies the current system in use defecting the problem facing the system, analysis of the problem and coming up with a modified system that will solve the current and further problem that may come up with little or no modification. This will do a lot of good.

1.7 Assumption of the Study

It is assumed that wireless voice over IP that are available in the nation today is not enough to serve the teaming population and among the available wireless voice over IP, many are faulty because of lack of maintenance.

1.8 Limitation of the Study

Our time and money was our major physical problem during the research of the project work (or should I say my time and money) with my studies and exams at hand, I just have limited time to carryout this research very extensively. However, I did a detailed research work.

1.9 Definiion of Terms

Computer:

Is an electronic device used for to accept data as an input, process the data, store the data and give out an out an output of that data as an information which has the ability to retrieve stored data.

Hardware:

Is the physical component of computer.

System:

Is the collection of all part of computer including human being.

Billing:

Is the process of preparing bill for the customer.

Staff:

Is the person working in an organization.

Storage:

Is a media for storing data/information.

Database:

Is the collection of related filed.

Telephone:

Is an instrument that sends and receives voice messages and data.

Telephone Call:

Is a communication carried out using the telephone.

Telephone Booth:

An enclosed or partly enclosed space with a pay telephone in it.

Telephone Number:

The sequence of number that identifies a particular telephone and that must be dialed for a caller to be connected to it.

LAN:

Local Area Network

WAN:

Wide Area Network.

Chapter Five

5.0 Summary, Conclusion and Recommendation

5.1 Summary

Voice over internet protocol telephone systems are susceptible to attacks as are any internet connected devices. This means that hackers who know about these vulnerabilities (such as insecure password) can institute denial-of-service attacks, harvest customer data, record conversions and break into voice mailboxes.

Another challenges is routine VoIP traffic through firewalls and network address translators. Private session Border controllers are used along with firewalls to enable VoIP calls to and from protected networks. For example, skype uses a proprietary protocol to route calls through other skype peers on the network, allowing it to transverse symmetric NATS and firewalls. Other methods to transverse NATS involve using protocols such as STUN or interactive connectivity establishment (ICE).

To prevent the above security concerns government and military organizations are military organizations are using voice over secure internet protocol (VoSIP), secure voice over internet protocol (SVoIP) and secure voice over secure internet protocol (SVoSIP) to protect confidential and classified VoIP communication. Secure voice over internet protocol is accomplished by encrypting VoIP with typed encryption. SVoIP is accomplished by using type/encryption on a classified network, like SIPR Network public secure VoIP is also available with free GNU programs.

5.2 Recommendation

In the future voice over internet protocol will increasingly integrate with business and educations to the point where it becomes essentially invisible. This will result in a change, in how we see the process of making a voice call-instead of only using voice to communicate with other people we will also be using voice to communicate with services in order for this integration to VoIP will have to integrate closely with applications built using service-oriented Architectures (SOA) Ascierto, 2005).

5.3 Conclusion

The nature of internet protocol makes it difficult to locate network users geographically. Emergency calls, therefore, cannot easily be routed to a nearly call centre. Sometimes, VoIP system may rote emergency calls to a non-emergency phone line at the intended department, in the united states at least one major police department has strongly objected to this practice as potentially endangering the public.

A fixed line phone has a direct relationship between a telephone number and a physical location. If an emergency call comes from that number, then the physical location is known.

In the internet protocol world, it is not so simple. A broadband provider may know the location where that wires terminate, but this does not necessarily allow the mapping of an IP address to that location. IP addresses are often dynamically assigned, so the ISP may allocated an address for online access, or at the time a broadband router is engaged. The ISP recognizes individual IP addresses, but does not necessarily know to which physical location it corresponds. The broadband service provider knows the physical location, but is not necessarily tracking the IP address in use.

There are more complications since IP allows a great deal of mobility. For example, a broadband connection can be used to dial a virtual private network that is employer owned. When this is done, the IP address being used will belong to the range of the ISP, so this could be many kilometers away or even in another country. To provide another example, if mobile data is used e.g a 2G mobile handset or USB wireless broadband adapter, then the IP address has no relationship with any physical location, since a mobile user could be anywhere that there is network coverage, even roaming via another cellular company.