(i) UDP- User Datagram Protocol
(ii) DNS - Domain Name System
(iii) OSI – Open System Interconnection
(iv) RFID- Radio Frequency Identification

There are four total layers of TCP/IP protocol, each of which is listed below with a brief description.
(i) Network Access Layer - Concerned with building packets.
(ii) Internet Layer - describes how packets are to be delivered.
(iii) Transport Layer - ensure the proper transmission of data.
(iv) Application Layer - application network processes. These processes include File transfer Protocol (FTP), Hypertext Transfer Protocol (HTTP), and simple Mail Transfer Protocol (SMTP).

(i) HTTP: A protocol used between a web client and a web server protects non-secure data transmissions. The core protocol of the World Wide Web.
(ii) HTTPS: A protocol used between a web client and a web server permits secure data transmissions.
(iii) FTP: Used between computers for sending and receiving data. Enables a client to send and receive complete files from a server.

Main components of RFID system
1. RFID tag: It has silicon microchip attached to a small antenna and mounted on a substrate.
2. A reader: It has a scanner with antennas to transmit and receive signals, used for communication.
3. A controller: It is the host computer with a microprocessor which receives the reader input and process the data.

Comparision between Internet, intranet and Extranet

S.No	Internet	Intranet	Extranet
Meaning	Several Networks, small and big over the world, are connected together to form a Global network called the Internet.	Intranet is a website used by organizations to provide a place where employees can access company related information	Extranet is a private network using Internet technology to share part of business information with supplier's parthers and customers.
Applications	Download programs and files	Sharing of company policies/ rules and regulations	Online education/ training
Network accessibility	Public Access	Private Access	Private Access

(i) Third generation of mobile systems merges different mobile technology standards, and uses higher frequency bands for transmission and Code Division Multiple Access to delivery data rates of up to 2Mbit/s supports multimedia services (MMS: voice, video and data) .
(ii) European standard is UMTS(Universal Mobile Telecommunication Systems).
(iii)  Mobile phones systems continue to use digital transmission with SIM authentication for billing systems and for data incorruption.
(iv) Data transmission used a WCDMA. WCDMA stands for (Wideband Code Division Multiple Access).
(v) One technique to obtain data rates between 384kbit/s and 2048kbit/s. Few 3G suppliers use ATM (Asynchronous Transfer Mode) for their 'over the air' network with in MPLS(Multiprotocol Label Switching) or IP for theirs backbone network.
(vi) Mobility still supported at layer2, and hence like 2G it still prohibits seamless roaming beyond heterogeneous access networks and routing domains.
(vii) The transmission were band frequencies are between 1900 and 2200 MHz. All UMTS license holders at the UK holds a 20-year license with the condition that 80% population coverage is achieved by 31 December 2007.
(viii) The present third generation licensed operators in the UK can be seen below as at August 2004.

Development of Mobile Networks :
The generations of mobile networks are as follows.
(i) First Generation(1G) 1981- NMT launch
(ii) Second Generation(2G) 1991-GSM Launch
(iii) Second to Third Generation Bridge (2.5)2000 — GPRS launch
(iv) Third Generation( 3G) 2003- UK 3G launch
(v) Fourth Generation (4 G) 2007
(vi) Fifth Generation (5G) 2019+
Merits of Mobile Networks :
(i) It provides both voice/data services.
(ii) It connects both fixed and wireless telephone users.
(iii) It is used in areas where cables cannot be laid out due to its wireless nature.
(iv) It is easy to maintain.
(v) It is easy to upgrade the equipments.
(vi) The ‘mobile and fixed subscribers are connected immediately with cellular network as soon as mobile phones are switched on.
(vii) All the handshake signals between mobile and base station are automatically exchanged.
Demerits of Mobile Networks :
(i) Cost
(ii) Vulnerable to Security risks
(iii) Additional training is needed to use new technology.
(iv) Cyber Crime.

No.	TCP/IP	OSI
1.	It is client server model. ie. when the client requests for service it is provided by the server.	It is conceptual model.
2.	It is standard protocol used for every network including the internet.	It is not a protocol but a reference model used for understanding and designing the system architecture.
3.	It is four layered model.	It has seven layers.
4.	TCP / IP follows vertical approach.	OSI model supports horizontal approach.
5.	It is Tangible	It is not Tangible
6.	It is follows top to bottom approach	It is follows a bottom-up approach

Open System Interconnection (OSI) model was found in the year 1934, general framework that enables network protocols along with software and systems to be developed based on general set of guidelines. It describes the standards for the inter-computer communication.
OSI Layers:
(i) Physical Layer: This is the 1^st layer, it defines the electrical and physical specifications for devices.
(ii) Data Link Layer: It is the 2^nd layer and it guarantees that the data transmitted are free of errors. This layer has simple protocols like "802.3 for Ethernet" and "802.11 for Wi-Fi".
(iii) Network Layer: It is the 3^rd layer determining the path of the data packets. This layer is responsible for routing of data packets using IP Addressing.
(iv) Transport Layer: It is the 4^th layer that guarantees the transportation/sending of data succeddfully. It includes the error checking operation.
(v) Session Layer: It is the 5^th layer, identifies the established system session between different network entities. It controls dailogues between computers. For instance, while accessing a system remotely, session is created between your computer and the remote system.
(vi) Presentation Layer: It is the 6^th layer that does the translation of data to the next layer (Prepare the data to the Application Layer). Encryption and decryption protocols occur in this layer such as, Secure Socket Layer (SSL).
(vii) Application Layer: It is the 7^th layer, which acts as the user interface platform comprising of software within the system.

INTERNET:
(i) The Internet is a worldwide system of computer networks- A network of networks where the users at any one computer can get information from any other computer.
(ii) The Internet is a network of global connections - comprising private, public, business, academic and government networks connected by guided, wireless and fiber-optic technologies.
(iii) The unique aim was to generate a network that would permit users of a research computer from one university to "talk to" research computers on other universities.
(iv) The Internet denotes to the global communication system, including infrastructure and hardware, whereas the web is one of the services interconnected over the Internet.
INTRANET:
(i) Intranet is a private network within an enterprise to share company data and computing resources between the employees.
(ii) It may consist of many interlinked local area networks.
(iii) It includes connections through one or more gateway (connects two networks using different protocols together known as protocol convertor) computers to outside Internet.
EXTRANET: Extranet is a private network that uses Internet technology and the public telecommunication system to securely share business information with suppliers, vendors, partners, customers, or other business.