The user creates a voluntary tunnel model. This model is typically uses a L2TP enabled client. An L2TP packet is sent by user to the Internet Service Provider which will in turn forward them on to LNS. The support of L2TP support is not needed by ISP. The L2TP tunnel initiator resides on the same system effectively playing as a remote client.
It consists of one or more BTS and BSC. Each BTS is related to one cell which includes an antenna , a video trans-receiver and a link to BSC.BSC controls multiple BTS units, manages the hand offs of the mobiles and controls paging.
When the received signal is not as same as the transmitted signal then it is known as Transmission impairment.
Three different types of transmission impairment are:-
The tunnel creation in compulsory tunnel, no action from the user and without allowing the user any choice is performed. Internet service provider access concentrator receives a point-to-point protocol packets from the user. The encapsulation of packets in L2TP and sending them through a tunnel to the L2TP network server is performed by the ISP. It is mandatory that the ISP is L2TP-capable.
Blue tooth technology uses Adaptive Frequency Hopping and capable to reduce interference between wireless technologies with the help of 2.4 GHz spectrum. In order to take the advantage of the available frequency, Blue tooth's AFH works within the spectrum and is performed by the technology detecting other devices in the spectrum and avoiding the used frequencies. Efficient transmission within the spectrum at high degree of interference immunity is achieved by adapting hopping among 79 frequencies at 1 MHz intervals.
Airport is standard (802.11) and has a faster transfer rate. Technologically it is more advanced, more rugged and smaller and capable of being used anywhere. It is 10mb/sec, 50 meters, 10 active devices. Apparently, Bluetooth is 1mb/sec, 10 meters and 7 active devices.
It includes mobile equipment which refers o a physical terminal such as telephone which includes the radio trans-receiver signal processor and the Subscriber Identity Module.
Public Key Infrastructure: A set of hardware, software, people, policies and procedures comprises the Public Key Infrastructure (PKI) and digital certificates are revoked. The arrangement of public key binding with respective of identification of users by means of a Certificate Authority , is done in PKI. Every certificate authority should have a unique user identity. The registration and issuance process that is depending on the level of assurance is involved in binding, which may be carried out be software at a CA. The binding assurance portrayed by PKI is known as Registration Authority. The public key certificates issued by the CA are comprised unforgettable user identity, public key and their binding, validity conditions and other attributes.
A digital certificate is a credential which validates the certificate owner's identity. The information provided by the digital certificate is known as ‘the subject distinguished name'. Certificate Authority issues the digital certificates to the users or the organizations. The trust in the certificate as a valid credential is provided as the foundation by the Certificate Authority.
Following are the differences between 3G and 4G:-
The following are the disadvantages of Symmetric Cryptosystems:
For Voice transfer, SCO (Synchronous Connection Oriented) links are used for good synchronization and reliability.
When a mobile moves into a different cell while a conversation is in progress, the Mobile Switching Center automatically transfers the call to a new channel belonging to the new Base Station.
Types of handoff:-
The following is the process for Tcp connection:
Bluetooth 2.0 is better than its predecessors because:
PPTP is one of the methods to implement Virtual Private Networks. Confidentiality or encryption does not provided by PPTP. The reliability of PPTP is being tunneled for the purpose of providing privacy. PPTP works by sending Point-to-Point Protocol to the peer with the Generic Encapsulation protocol. Because of its easy way of configuration, it is most popular protocol used in VPNs. It was the first protocol for VPNs and was supported by Dial-up network of Microsoft.
It controls hand offs between cells in different BSSs, authenticates users , validates and maintains their accounts.
It is mainly supported by four databases:-
Wireless communication is the transfer of information between two or more points that are not connected by any physical medium.Wireless communications can be via:
Challenge-Handshake Authentication Protocol authenticates to an authenticating entity of a user or network. The entity can be an Internet access provider. CHAP is used by Point-to-Point Protocol that servers for the validation of identifying of remote clients. The identity of the client is verified by CHAP periodically with the use of a three-way handshake. This situation occurs when an initial link is established and maybe repeated after at any time. The shared secret is the base for verification. CHAP protection to play back attack by the peer. This is done by using an incrementally changing identifier and of a variable challenge-value. Both client and server need to know about the plain text of secret which uses CHAP.
Internet Control Message Protocol: This protocol is used for while checking the connectivity using ping command
Address Resolution Protocol: This protocol is used to know about the properties of TCP/IP. For example, to know other system MAC addresses.
Multicast: Communication between single sender and a list of select recipients in a network.
Broadcast: To send messages to all the recipients simultaneously in a network.