The composition of Architecture in Wireless Networks

Computer network architecture and protocols and consist of components required in running an application. One network standard that has been discussed on the front of this book is a reference model architecture and the Open System lnterconect or OSI. Standardize the 0S1 reference model is also very useful in describing some of the network standards and interoperability, including the wireless jaingan.
Broadly speaking, functional OS1 seven layer reference model is:
Layer 1 - Physical Layer. This layer is physically connected to one another and provides actual transmission and information through the media, either wired or wireless. This layer represents the flow and bits (binary digits 1 and 0) in the form of electrical pulses, radio signals, or a ray of light through a network of electrical and mechanical level. This layer is the hardware layer is responsible for sending and receiving data on the carrier (carrier) temiasuk wiring. cards, forms a connection port, as well as physical aspects of other mark.
Layer 2 - Data Link Layer. At this layer data packets will be decoded in the encoder and the arrangement of the bits. The data is broken up into data frames, then transmitted and sequenced. Next, frame synchronization settings will be processed if an error occurs in both the sender and receiver. Data link layer is divided into two sublayers, the Media Access Control (MAC) and Logical Link Control (LLC). MAC sublayer will govern how computers on the network gain access to data and its permissions to then perform the transmission process. LLC sublayer will set the synchronization layer, the flow of data, and perform checks if an error occurs. Wireless networks typically include coordinating media access through the air and how the recovery process if an error occurs when the propagation of data from the sender and recipient data.
Layer 3 - Network. This layer provides a process of determining the route packets across the network and the sender to the receiver. This layer also provides some kind of technology to perform switching and routing, create a logical path is called a virtual circuit, and perform data transmission and node to node. Routing process is useful to ensure that data packets are sent in the right direction for a particular purpose. Protocols such as Internet Protocol (IP) operates at this layer. In addition to the routing process, the process undertaken by this layer is the process of forwarding, addressing methods, intemetworking, error handling, data collision control, and package sorting process.
Layer 4 - Transport. This layer is called layer host to host or end to end, meaning that this layer provides transparent transfer of data between end systems (hosts) and is responsible for the method error rocovery end to end. This layer also have a function as a regulator of the flow of data and always mernastikan completeness of the data transfer process when done. Examples of protocols that operate at this layer is the Transmission Control Protocol (TCP).
Layer 5 - Session. This layer serves to establish, manage, and terminate the connection antaraplikasi. This will set the coordination layer, halting inter conversations, data exchange, and dialogue antaraplikasi. In the wireless middleware model, an access regulator will be tasked with providing a form of connectivity on the wireless network. If there is interference on the wireless network, this layer will make the communication delay until the interference disappeared.
Layer 6 - Presentation Layer. Layer is in charge of negotiating data transfer syntax-syntax for application layer and serves as peneijemah between different data formats. This layer will do the translation and the coding process to represent the data while communicating on the system developed by different vendors, so the layer and the encryption of data is sent across the network without Hares always consider compatibility issues.
Layer 7 - Application Layer. This layer provides communication between the user with a standard communication services such as traansfer and email. Some of the software that runs on top of this layer is the Simple Mail Transfer Protocol (SMTP), Hypertext Transfer Protocol (HTTP) and File Transfer Protocol (FTP).
Layer on a combination of the above network architecture defines the same functionality in wireless networks. However, the only wireless network is implemented directly on the bottom layer of the OSI model. For example, a wireless NIC (Network Interface Card) is implemented in the function of physical layer (phy) and the data link layer. However, attention to the layer above it is necessary to ascertain whether the application operates effectively on wireless networks.
Digital Signal Information
Data is the type of information to be mediated network and stored on a computer and can be retrieved and permanent storage. On the wireless computer networks, transfer data from one computer to another has become the standard for the development of network systems in general. The data transferred includes email messages, files, web pages, multimedia files, and even voice conversations. In the wireless communication system, data will be symbolized in a certain code in the form of electrical signals, radio, and light. Than the carrier signal carries information through the system and one point to another place. Form of signals, whether digital or analog signal form, will depend on the location where the system is located.
Usually in the form of a binary digital signal, and is generally called a binary digit sexing or binary data. Binary or binary is a system that recognizes only the digits 0 and 1. One advantage is the ease in the digital signal to regenerate the signal. Signal will propagate through the medium of air, so the possibility of interference and noise will occur that will affect the performance of this signal strength. Necessary to repeat the signal digital circuit that will detect and generate new digital pulse at a specific time period. Such circuits will form a new pulse of exactly the same as the original message received. Thus, digital signals can be transmitted within a great distance through a repeater which periodically will control the integrity of that information.
Here are some important characteristics of the digital signal, where this term is always used in its entirety:
Data rate. Data transfer rate speeds associated with digital signal through a wireless network. Data rate on a digital signal will provide a view whether the data can be transmitted and one point to another, and will identify the amount of effective bandwidth in the media, so that it can supply and support the existence of a digital signal.
Data rate of a signal is the total number of bits transmitted are associated with the time required to perform the delivery. Common unit used to measure the bit rate is bits per second (bps). For example, there are 1 million in a second signal, so the data rate signal is 1,000,000 divided by a second equal to 1,000,000 bits per second or 1Mbps.
Throughput. Basically the same as the data throughput rate, but in general the calculation of throughput eliminating extra bits (overhead) are included at the time of the communication occurs. There is no standard to display the throughput, but usually Iroughput the actual information transmitted over the network. Throughput to provide accuracy in the representation of network performance and efficiency, especially in wireless computer networks. The higher throughput, network performance will increasingly balk. Throughput can be considered as the percentage ratio between the input and output data on wireless networks.
Overhead in the data is usually a header in each frame, the fields containing the error control, frame identifier, and retransmissions due to errors. As a result, the information will be weighed down and slowed traffic. If in a network memunyai data rate 11 Mbps, but actual throughput is only about half of the digital signal, or about 5 Mbps, then the overhead will be ignored.
As Media Air Data Exchange
In wireless networks, the media used as the interface or the interface is the medium of air. When the computer equipment will transmit information over a wireless network, the first step is to negotiate a connection to the remote computer is using the functions in the transport and session layer. After getting the computer connections, computer equipment will transmit data in digital form to a NIC (Network Interface Card) wireless. Furthermore, the wireless NIC will send a frame that contains information on adjustments to certain standards, such as the IEEE 802.11 standard to a remote computer or the access point.