LAN (Local Area Network): 2014

Rabu, 17 Desember 2014

Wireline

Wireline The function of the network is to share its resources and to communicate electronically. • A network typically consists of two or more computers that are relate. • Computer Network works with the use of wireline cables as liaison between computers. • The cable used is a coaxial cable, twisted pair, and fiber optics. • On each computer must be equipped with interface card called with NIC (Network Interface Card) or LAN (Local Area Network) • Network cable is typically used on small areas, for example in a room and the building. • Every computer connected to the network has a MAC address or IP address (Internet Protocol) different.

Wireline Networks of Excellence • Data transmission 10 s.d. 100 Mbps, • Delay or a connection between computers quickly, • Data transmission running smoothly • Cost of affordable equipment Weakness wireline networks • The use is limited to one affordable place wires, • Time for the old installation • Requires the place and location of permanent network • Requires regular maintenance costs • It is difficult to migrate Network Wireless (Wireless) • Along with the sophistication of information technology, to build a computer network can be made possible without the use of cable (wireless). • To replace the connecting cable can be used as a wave radio (Radio Frequency), infrared light (infrared), Bluetooth, and via microwave (microwave). • mobile computer, such as notebooks and Personal Digital Assistant (PDA) is a computer that can be used on a wireless network.

The advantages and benefits of wireless networks: • Mobility Wireless -Network provide real-time access to network users anywhere while in the access limits. • Speed of Installation The process in the network installation is relatively faster and easier because it does not require cables to be installed as a liaison. • Flexibility place Wireless network or wireless is very flexible on where, in contrast to the cable network is not possible to be installed without wires. • Reduction Budget -When A transfer occurs, the budget can be reduced even though the initial investment in a wireless network is more costly than wired networks. Installation costs can be reduced because it does not require wiring and maintenance costs were cheaper. • Ability to Reach -Configure Network can be changed from a peer-to-peer for a small number of users into the network infrastructure more. In fact, can reach thousands of users that can roam with a wide range. Weakness Wireless Networks • Data transmission is only 1-2 Mbps which is much lower amount when compared to the wired network. • Transmission of data from different computers can interfere with each other. • The cost of expensive equipment. • There is a time delay or a great connection • The radio propagation problems, such as blocked, reflected, and many sources of interference. • Network capacity limitations caused by spectrum not great (frequency band can not be extended). • Data security or confidentiality of data is less reliable. • The signal is discontinuous (intermittence) caused by the presence of objects blocking the signal

Network with Modem • The modem is an electronic medium to connect computers to the Internet network. • The modem works using digital signal translates into an analog signal to be transmitted and vice versa, translating analog signals into digital signals. Based on the technology, the modem can be distinguished: • Dial-up Modem (Modem Phone) • Cable Modem • DSL Modem Dial-up Modem • Working with using a wireline network is wired telephone. • To be able to subscribe to the Internet with a dial-up models can contact your ISP (Internet Service Provider). • type dial-up modem on the market consists of an internal modem and an external modem. • The internal modem is installed on the mainboard expansion slots while the external model is mounted on a computer using a serial data cable or data cable USB. • In Indonesia, some ISPs provide services to the Internet with a dial-up modem including Telkomnet, Indosatnet, Wasantaranet, and CBNnet. • To date, the dial-up internet access. Network with Modem • The modem is an electronic medium to connect computers to the Internet network. • The modem works using digital signal translates into an analog signal to be transmitted and vice versa, translating analog signals into digital signals. Based on the technology, the modem can be distinguished: • Dial-up Modem (Modem Phone) • Cable Modem • DSL Modem Dial-up Modem Cable Modem • Cable Modem has a way of working that resembles how the Network Interface Card (NIC) or ethernet card that is installed on a computer to a Local Area Network (LAN). • The difference between how the modem with ethernet is the distance problem. Modem is not influenced by the distance despite only having a speed of 50 Kbps (kilobits per second), while the ethernet which has a speed of 10 or 100 Mbps (megabits per second) can only be within a maximum distance of approximately 1 km. Cable modem speeds ranging from 3-56 Mbps, and can work within a distance of 100 miles more. • The work process is separate from the cable modem from the cable TV signal into two signals to television and data signals are connected to the cable modem. Both signals it will not interfere with each other. Then the cable modem is connected to the network card (Network Interface Card) contained in the PC (Personal Computer). Downstream data rates (incoming signal) average ranges between 4-56 Mbps. • To be able to connect the Internet, cable television service providers to connect itself to the Internet backbone service providers greater, namely the connection OC-3 (155 Mbps) or multiple redundant OC-3. Multiple redundant OC-3 can handle the bandwidth requirements of many customers. • To be able to connect the Internet, cable television service providers to connect itself to the Internet backbone service providers greater, namely the connection OC-3 (155 Mbps) or multiple redundant OC-3. Multiple redundant OC-3 can handle the bandwidth requirements of many customers.

• Currently, DSL (Digital Subscriber Line) is The main competitor of cable modems. • In terms of speed and cost is no different away with the cable modem. • Technology for a new DSL modem available is ADSL (Asymmetric Digital Subscribber Line). • In Indonesia, not all the areas covered by DSL technology. • ADSL telephone cable network that has been upgraded or have specific enhancement. ADSL does not require a second phone line but need a splitter to the division between the modem to the phone. • ADSL speed is not too much different from the cable modem, where the downstream speed (data entry) a maximum of 1.5 Mbps and upstream speeds (data out) ranged from 64 Kbps. ADSL technology will develop a modem with a speed of 52 Mbps, approximately 50 times better than the current one.

Excess Media Satellite

Excess Media Satellite, namely: 1. Connection anywhere. No need to LOS (Line of sigth) and there is no problem with distance, 2. Reach broad scope of national, regional and global, 3. The relatively rapid infrastructure development for large areas, compared to terrestrial, 4. Communication can be done either point to point or from one point to many points in broadcasting, multicassting, 5. Bitrate high and wide bandwidth access, 6. VSAT can be installed anywhere for entry in satellite range, 7. Reliable and can be used to connect voice, video and data, by providing a wide bandwidth, 8. If the access network to the Internet directly to the ISP / NAP router with reliability approaching 100%, 9. Very good for sparse population density areas and does not have any telecommunications infrastructure. Satellite Media deficiency, namely: 1. The amount of throughput will be limited due to the propagation delay of a geostationary satellite. Now a variety of techniques already developed link protocol that can overcome these problems. Including the use of Forward Error Correction which ensures a small probability of retransmition, 2. Time required from one point on Earth to another point through the satellite is about 700 milliseconds (latency), while leased lines only takes about 40 milliseconds. This is caused by the distance that must be taken by the data that is from the earth to the satellite and back to earth. Geostationary Satellite own altitude of about 36,000 kilometers above the Earth's surface. 3. Highly sensitive weather and high rainfall, higher frequency signals are used, the higher attenuation due to rainfall. 4. Prone lightning strike.

The development of information

The development of information and communication technologies in line with the progress of time requires increased knowledge and skills in using the technology tools. For that, we need to study and understand the technology well in order to provide more knowledge and information up to date. In the face of the development of information and communication technology, we are required to learn at an early age so that we can contribute optimally. This material is intended can provide most of the material for you to have enough stock to understand the use of information and communication technology equipment, and understand the future prospects. With this material also expected you have a horizon of thought and knowledge in general and in particular that today many are needed in everyday life. Until the current information technology is growing very rapidly along with the discovery and development of science in the field of information and communication. It is able to create tools that support the development of information technology, ranging from communication systems through a direct communication tool as well as a two-way (interactive). Basically, information technology equipment includes three main tools: A. Computer systems; B. Network Communication Systems; C. Net Tools. A. Computer Systems Computer is an electronic device that is capable of receiving, processing, and storing the data, and generates output in the form of text, images, symbols, numbers and sounds. In operation, the form, the system and its function, the computer consists of two (2) parts: hardware and software. 1. Hardware To meet the demand for the kinds of information, people always to develop the hardware to support it. To accommodate this interest, he creates a variety of tools that support these desires. Computer hardware devices can be grouped into an input device (Keyboard, Scanner), the process (including: CPU), output and storage devices (such as: monitors, and printers), and a data storage device (such as: CD-ROM, Compact Disc, floppy disk, Hard disk). Details on computer you will earn well Keyboard is a tool to enter data or commands to the CPU (Central Processing Unit). The keyboard usually consists of a series of letters and numbers. Scanner is a tool to enter data such as image / graphics and turn it into a digital form that can be processed and combined with the form data in the form of text. Central Processing Units (CPU) is tool that serves as a processor (processor) data. CPU is a series circuit that stores instruction-processing instructions, and temporary data storage. Monitor is a tool that can display text or image of the data processed in the CPU. The printer is a tool to produce a data output (output) print the form, either in the form of text and pictures / graphics. CD Rom is an additional tool (instrument peripherals) that is capable of storing and write data and programs through media Compact Disk (CD). This tool is designed to be able to write and read data or program through Optical system. Compact Disk (CD) is a storage medium made of plastic material. The process of storing and reading data using an optical system. Software is a computer program that contains a set of instructions that is made using a special language. This Program, gave orders to the computer to perform various operations / processing of the data contained in the program or the data entered by the user computer. In short the software is a 'soul' while the hardware to function as a 'body' in a computer. In general, the software can be classified into two (2) classes of system software and application software. Discussion specifically about the software you will get on another occasion. B. Network Communication Systems Communication network is a system that is able to connect and combine multiple points of communication into a single entity that is capable of interacting with one another. Telephone is a two-way communication tool that allows two or more people to talk without being limited distance. Integrated Services Digital Network (ISDN) is a specialized communication network that uses the telephone network meproses not only sound, but also able to handle data storage in the form of text, images, video, fax, and others. Facsimile is a tool that is able to send documents in exactly the same over the telephone network. Fiber optic is a communication network that is capable of transmitting data in high frequency. In this network communication paths do not use copper wire but uses light as a conductor of the data. Leased lines are fixed telephone network (permanent) that connects two or more sites. This network does not have the tools switcher (switching) or the like, this network working between places that are specifically linked or predetermined. This network is also known as private line. Wirekess is Wireless communication network. Communications network that uses radio waves / specific frequency that serves as a conductor of information. This communication network using a transmitter, amplifier, and the wave receiver that contains the data. Wireless communication network that uses satellite that serves as a transmitter, receiver and amplifier. The communication system using wave as a conductor of data The antenna is a device used to transmit and receive radio communications. TV and Radio is a means of delivering information (mass media) that uses sound waves as a conductor signals and images. Mobile communication is communication that uses radio transmission to transmit signal information, the tool is better known by the name of mobile phones. C. Net tools Various ways humans use to facilitate and maintain the quality of the connection through the internet. Since then, the tools that support the ability to network (net tools) is growing rapidly. Network system that was only used by a limited circle now very familiar even to the household level. 1) Server A computer that works as a data provider, the provider of software and data storage is server. Even a server capable of regulating the flow of information in a network that regulates. 2) Client Client is a personal computer (PC) in a communication network that has the ability to process the data and is able to ask for information to the server. 3) Router A router is a device used in a network that is able to transmit data to other networks through more quickly, accurately and efficiently. 4) Modem Modulator / Demodullator is a tool that allows PC, Mini Computer, or mainframe to receive and send data in digital form through the channel telephone.

Kamis, 04 September 2014

Disadvantages satellite system

Internet applications have been widely used by both businesses and individuals and the tendency will be the life style of a society in which to trade, send mail etc. all Internet-based entertainment. Access to the internet is still dominated by the use of terrestrial network whether it be copper or fiber optic cables.
In the face of this global era internet, satellite systems can also be developed to support the services it. Among the weaknesses possessed by the satellite system when compared to terrestrial networks, there are several unique advantages which can be utilized and a high potential to support multimedia applications such as for broadcasting and multicast.
Disadvantages satellite system
, in this case is the delay or latency, in Internet applications can be overcome by using several techniques such as TCP Extention, TCP TCP spoofing in order to get better performance.
The majority of the backbone network and access the internet using terrestrial networks, such as: copper and optical cables, the bandwidth varies from hundreds to kilobyte megabyte. Despite dominating the cable internet access, but the study of the use of mobile networks / wireless for wide-bandwidth applications also accomplished.
Among the network of mobile / wireless, GEO satellite network has a high potential of the multimedia applications with the ability to broadcast and multicast large amounts of data at very wide area so as to give the possibility of global relations. Distribution of Internet via satellite in GEO satellite in particular, provide several benefits / advantages:
Wide bandwidth: satellite operating at Ka-band frequencies (20-30 GHz) can deliver throughput will be in the order of gigabits per second.
Relatively inexpensive: a satellite system is relatively cheaper because there are no deployment costs and one satellite can cover large areas.
Network topology is simple: compared with a mesh interconnect models on the terrestrial network, GEO satellites have a simpler configuration. With a simple topology, the network performance is more easily controlled.
On the other hand, satellite communication raises a major problem for Internet applications, the latency between the earth station / terminal. For a GEO satellite communication systems, its latency of at least 250 m-sec. Sometimes it is also coupled with the framing process, queing, as well as on-board switching so that its latency can range to 400 milli-seconds. Latency is approximately 10 times higher than that of fiber-optic point-to-point. Latency is not much effect on data transfer applications or broadcasting, but very influential on interactive applications that require handshaking, and unfortunately TCP requires the interaction.
LEO and MEO satellites can also provide broadband capacity as well as global. Latency in LEO approximately two times greater than the terrestrial network. Due to the nature of satellites in LEO and MEO are not fixed to the earth it is necessary constellation to provide a global service. With this constellation raises a high level of complexity in the satellite control and network management (as required handoff, tracking and routing) compared to GEO satellites.
Internet Applications
Common Internet applications including: Web browsing, file transfer protocol (FTP), remote login (Telnet), video conferencing, e-mail, and broadcasting. The above applications have different requirements in terms of bandwidth, speed of response, tolerance to noise that would cause different performance. For example: Remote logins are very sensitive to delay. Normally the user / user expects a quick response during the login session, while videoconferencing can usually receive a packet is lost or an error due to the transmission.
Figure 1 below shows the variation of the need for bandwidth and speed of response. Because of these differences, the implementation will be very different techniques. Some applications require distribution information (using TCP and sensitive to latency). Others can use UDP or other real-time protocol that can tolerate delay so it can work well via satellite.

TCP on Network with High Delay
Currently many Internet uses TCP to its main applications. TCP performance on high-delay network Air have direct influence on the performance of Internet access that uses GEO satellites. This delay will be especially slow when transferring large files. One-way delay in GEO approximately 250-270 milliseconds, while the TCP protocol requires that the receiver must send an acknowledgment to the sender to inform that segment sent has been received and waiting for the next segment. So for the delivery of the required segment approximately 500-540 milliseconds, the value of this will be a very slow process of data transmission.
If we have a T1 link (1.544 Mbps) and transmits each segment 64 KB TCP window, it will take 339 milliseconds to transmit segment. Receiver will receive a segment after 270 milliseconds and the sender will receive an acknowledgment after the next 270 milliseconds, so it takes 879 milliseconds to transmit a complete segment.
The following will be delivered performance issues that are important in the use of TCP.
window Size
TCP flow-control stems from the concept of "Window Size" .. Currently the maximum TCP Window Size is 64 Kb. In the high-delay network will air many packages that can not be acknowledge. To maximize utilization of the bandwidth in satellite networks, TCP requires a larger window size. For example, a satellite link with the round-trip delay of 0.8 seconds and a bandwidth of 1.54 Mbps then theoretically optimal window size is 154 kb (Far above the existing standard is 64 Kb).
A TCP-Extention, known as TCP-LW (Large-Window), is defined to widen the window size from 216 to 232 thereby allowing utilizes the bandwidth optimally and to obtain better performance through a satellite link.
Bandwidth adaptation
TCP is able to adapt to network bandwidth by performing his set window size. Adaptation speed is directly proportional to the latency. In satellite networks, adaptation requires a longer time and as a result the TCP congestion control becomes ineffective.
slow Start
Slow Start was introduced in 1988 by Jacobson and declared as one of the requirements in 1989 Slow start is used to gradually increase the data rate to the network. It starts by sending a single segment and wait for an acknowledgment from the receiver. For each acknowledgment received by the sender, the two segments will be sent to the network, in order to obtain an exponential increase in data transmission. Slow start stops when the window is reached or detect a loss of data.
Due to the time it takes a slow start to reach the available bandwidth is a function of round-trip time, the satellite links are very sensitive to the limitations of available throughput during slow start.
On one side of a slow start before obtained congesti prevent bandwidth availability assessment, on the other TCP bandwidth utilization becomes not optimal for its assessment process. So that the shorter ends of TCP slow start, the better the achieved performance.
Approaches for Improved Performance
There have been many techniques developed to reduce the effects of latency. The first alternative is to adopt a version of TCP that provides good performance in satellite and through terrestrial does not reduce performance. The second approach is to rely on satellite gateways to perform specific functions in accelerating TCP session. While the third approach is to develop a better implementation on general applications use TCP to obtain a more efficient and more sensitive. Here are some alternatives to increase TCP performance.
TCP Extention
Some of the problems that exist in the current GEO satellite system will appear also in the high-speed terrestrial network fiber future. Issues such as the width of the window size, slow-start period is longer, and inefficient bandwidth adaptation will affect both the network. Various techniques have been mentioned above, such as TCP-LW can be used.
middleware
Performance improvement in some things can be done by working directly on the level of infrastructure without the need to make modifications to its TCP, which is known as the middleware layer. If you make modifications to the TCP required changes to the operating system of each end host, while this technique is only necessary to change a little or even without any changes. There are two types of middleware, namely:
Split TCP
The idea is to split the Split TCP connection end-to-end TCP into two or three segments. Each segment is a complete TCP connection. Forwards the data flow from one segment to another segment (if necessary buffering). If the TCP Split performed on the satellite link, the middle segment bridging the satellite link, while the other segment connecting the routers that connect the internet terrestrial and satellite links to the endpoints.

This separation is able to isolate the impact of long latency. If the first and the last TCP segment is a network with low latency, then the TCP slow-start can be accelerated so that the window can be applied to normal size and works well. However the middle segment (satellite link) require special treatment such as widening the window size. This technique requires only minor changes to the software.
TCP Spoofing
In this technique, intermediate gateway (typically using a satellite link) considers receives TCP segment is in good condition without the need to wait for an acknowledgment from the receiver. This gives the illusion of a network with low latency at the sender so that the TCP slow start phase can be accelerated, as shown in Figure 3 Intermediate buffer gateway TCP segment. When the acknowledgment is actually received by the gateway, the gateway will be removed by the acknowledgment in order to prevent a double in the sender side. If acknowledgment is not accepted and the gateway also experience time-out, then it will be done from the retransmit buffer. As Split TCP, TCP spoofing to break the concept of semantic end-to-end TCP because the sender thinks that a segment has arrived at the destination when in fact it is still on the way. These techniques can be accepted by many applications such as WWW browsing through a proxy, but will cause problems if an application built using end-to-end semantics.
Potential Use of Satellite
Network used by companies essentially asymmetric in other words most of the time data flows in one direction and slightly in the opposite direction. For example: software distribution to remote areas, sending financial data to the central office, distribution of multimedia files etc.. For these types of applications over satellite provides an alternative solution. It also assures that communications to the unreached areas of terrestrial telecommunications infrastructure. Broadcast satellite communications can offer a channel for data communication that is economical and efficient. In a simple broadcast technology enables the delivery of information to customers at the same time. But in some cases, the information is not disseminated to all the customers, but only to some customers. So the operator must be able to disseminate information selectively to the purpose.
Satellites in GEO are very suitable as a medium MBONE (Virtual network via the Internet for multicast applications). Currently for terrestrial use MBone, the data must go through the links in huge quantities and replicate itself on routers that very much. (See Figure 4 below). This takes up substantial bandwidth and increase the likelihood of congestion at each router along the path.

On the other hand, can be multicast via satellite delivers the data directly to end-users or hosts with minimal cost. Figure 5 below shows the MBONE using a satellite connection.

Satellite network promises a new era in global relations, but also offers a new challenge to the common applications via the Internet. Various internet service or application can be applied to the satellite network such as: videoteleconferencing, MBone multicast, the bulk of data trasfer, electronic mail, as well as the dissemination of information that is non-real-time. But some interactive applications are very disturbed because the standard TCP inefficiencies that exist today on the links with high latency. However the performance can be improved by applying techniques as described above though needed deeper study their effects on the overall Internet network.

Type connection

Type connection to the internet without wires (wireless)
1. GPRS (High Speed Internet Access-GPRS)
Of course you know the phone (HP) is not it? The need for mobile communication industry will be one of the causes of GPRS data communications technology that is widely used today. GPRS stands for General Packet Radio Service which voice and data communications are performed using radio waves. GPRS has the ability to communicate data and voice at the time of mobile communication devices (mobile).
GPRS system can be used for data transfer (in the form of data packets) that are associated with e-mail, image data (MMS), and search (browse) the Internet. GPRS service is installed on your phone type GSM and IS-136, although the current GPRS network apart from GSM.
In theory, GPRS promises speeds ranging from 56 kbps to 115 kbps, allowing internet access, multimedia data delivery to computers, notebooks and handheld computers. However, in its implementation, it depends on the following factors:
Configuration and allocation of time slots at the level of BTS
Software used
Support mobile phone features and applications that are used
This explains why at certain times and in certain locations GPRS access is slow, even slower than the speed of access to CSD which has 9.6 kbps.
2. 3G (3G-Speed Internet Access)
3G (read: triji) is an abbreviation of the term in English: third-generation technology. The term is generally used refers to the development of wireless telephone technology (wireless).
3G as a wireless solution that can provide access speed:
Amounted to 144 Kbps for fast-moving conditions (mobile).
Of 384 Kbps for running conditions (pedestrian).
Of 2 Mbps for static conditions somewhere.
3G network is not an upgrade from 2G; 2G operators affiliated with 3GPP need to replace a lot of components to be able to provide 3G services. While 2G operators affiliated with 3GPP2 technologies easier to upgrade to 3G because of its wide range of network elements in the direction it was designed for broadband wireless services (wireless broadband). Telecom mobile phone network has increased towards the use of 3G services from 1999 to 2010 Japan was the first country to introduce 3G nationwide and transition to 3G in Japan has been achieved in 2006 after the Korean became the first adopters of 3G networks and the transition has been achieved in the early in 2004, lead the world in the field of telecommunications.
3. Wifi (speed Internet access-WiFi)
Have you ever seen a wireless communication connection? The technology known as wirelless Fidelity (WiFi). Wireless network technology uses high frequency is at 2.4 GHz spectrum. Wi-Fi has a standard set of terms that are used for Wireless Local Networks (Wireless Local Area Networks - WLANs) based on IEEE 802.11 specification. The latest standard of 802.11a or b specifications, such as 802.16 g, is currently in preparation, the latest specification offers many improvements ranging from broad coverage even further up the transfer speed.
Wi-Fi (Wireless Fidelity) is a wireless connection such as mobile phones using radio technology, so users can transfer data quickly and safely. Wi-Fi not only can be used for internet access, Wi-Fi can also be used to create a wireless network in the company. Because of that many people associate with the Wi-Fi "Freedom" because of Wi-Fi technology gives freedom to users to access the internet or transfer data from the meeting room, hotel room, campus, and the café is marked "Wi-Fi Hot Spot". Also one of the advantages of Wi-Fi is practicality, not to bother installing network cable. For the problem of speed depending on the signals obtained.

several types of connections

several types of connections to the internet, either using a cable (wire) or cordless (wireless). This is supported by the development of information and communication technology today allows us to connect our computers to the Internet through a variety of ways, as for the types of connections as follows:
Type of connection to the internet with cable
1. Dial-Up (Speed-Dial Up Internet access via the PSTN Line)
Is already installed in your home phone line? Telephone network has been penetrated by wide. If we have a computer already and then we can connect to the Internet. How to connect your computer to the Internet using a regular phone cable or more commonly referred to as dial up. Dial-up via the PSTN (Public Switched Telephone Network) is the way we. connected to the ISP (Internet Service Provider) through the regular telephone network (PSTN) example is "Instant Telkomnet" Telkom ISP.
Dial-up Connection is generally used by individuals who want to access the Internet from home. Computers are used for dial-up in general is a single computer (not the computer network). Speed Internet access using a dial-up can reach maximum speed of 56 kilo bytes persecond (kbps).
2. ADSL (speed Internet access-ADSL)
ADSL (Asymetric Digital Subscriber Line) is a modem technology that works at a frequency between 34 kHz to 1104 kHz. This is the main cause of the difference in the speed of data transfer between an ADSL modem with a conventional modem (which works at frequencies below 4 kHz). The advantage of ADSL is to provide high-speed internet access capability and voice / fax simultaneously (on the customer side by using a splitter to separate the telephone line and a modem line).
What is the maximum bandwidth is obtained when we use the Internet access using ADSL: For line rate of 384 kbps, the maximum bandwidth is obtained close to 337 kbps, 384 kbps to line rate, average throughput (download speed) can be obtained approximately 40 Kb / s, to the line rate of 512 kbps, which is obtained close to the maximum bandwidth of 450 kbps. For a 512 kbps line rate, average throughput (download speed) that can be obtained is about 52 Kb / s.
3.LAN (High Speed Internet Access-LAN)
One way to connect to the internet is to connect your computer to a computer network that is connected to the internet. This method is widely used in corporate, college campuses, and the cafe-cafe. A computer that is used as a server (computer services) connected to the internet. Other computers on the network are then connected to the server. Usually a computer acting as a server connected to an Internet Service Provider (ISP) over a telephone line or via an antenna. While the computer to connect to the server computer is done by using a LAN card (LAN card) and coaxial cable (UTP).
Commonly abbreviated Local Area Network LAN is a computer network that covers only a small area network. Currently, most LANs based on the IEEE 802.3 Ethernet technology using a switch device, which has a data transfer speed of 10, 100, or 1000 Mbit / s. In addition to Ethernet, the current technology 802.11b (or so-called Wi-Fi) is also often used to form a LAN.
4 Cable TV (Speed Internet Access)
Have you ever heard of the TV / cable TV? TV broadcasts often to offering cable TV sets. Cable TV networks to connect computers to the Internet has been widely used. Cable television is considered suitable especially for the internet user of the family (household). Excess accessing the internet using a cable TV network can access the internet at any time and free of distractions busy phone.
The cable TV network can be used to connect to the internet with a maximum speed of 27 Mbps downstream (download speed to the user) and 2.5 Mbps upstream (from the user upload speed). In order to use the cable modem, the computer must be equipped with an Ethernet card (Ethernet card).
In the home network, the cable from "cable TV" using coaxial cable and installed a "dividing line" (splitter) cable. After the cable from the network (network cable) pass splitter, cable channeled into two channels, one for TV and one to the cable modem. Of a new cable modem to the ethernet card and then to the computer.

BaseStation Clone

Wireless technology is good for connecting between distant areas. However, this technologically has weaknesses, especially in terms of security. Generally, the disorder is often encountered in WiFi technology include:
1) Insertion Attacks, which can attack the network by inserting something without permission.
2) interception and monitoring of wireless traffic, such as messaging / data by broadcasting (broadcasting) into the network. Disruption of this model are generally known by various terms such as, Wireless Sniffer, Hijacking The Session, Broadcast Monitoring, arpspoof Monitoring and hijacking, and BaseStation Clone (Evil Twin) .f
3) Misconfiguration, which can be caused by a misunderstanding of the user, or the unavailability of network blueprints. It could also be due to a physical disability hardware.
4) Client to Client Attacks, by utilizing the filesharing service or use TCP / IP.
5) Denial of Service (DoS) in the form of sending the file as a virus that can record user activities to obtain data (Hybrid Threats).
6) interference resulting network can not be used. This is because the WiFi uses the 2.4 GHz frequency that does not require a license from the government and WiFi access points can be bought freely. Naturally, if the interference is possible because of the nature of the network is free.

Wireless network technology

Wireless network technology is actually stretching ranging from voice communication to data networks, which allow users to establish a wireless connection at a certain distance. This includes infrared technology, radio frequency, and so forth. Devices commonly used for wireless networks including the computers, handheld computers, PDAs, mobile phones, tablet PCs and so forth. This wireless technology has so many uses. For example, mobile users can use their mobile phones to access e-mail. Meanwhile the travelers with laptops can connect to the internet when they are in airports, cafes, trains and other public places. At home, users can connect to their desktop (via Bluetooth) to synchronize with his PDA.
standardization
To reduce costs, ensure interoperability and promote the widespread adoption of wireless technology, then organizations such as the Institute of Electrical and Electronics Engineers (IEEE), the Internet Engineering Task Force (IETF), the Wireless Ethernet Compatibility Alliance (WECA) and the International Telecommunication Union (ITU ) has participated in various standardization efforts. For example, the IEEE working group has defined how the information is transferred from one device to another device (using radio frequency or infrared, for example) and how and when a transmission medium should be used for communication purposes. When building standards for wireless networks, organizations such as the IEEE has also overcome the problem of power management, bandwidth, security and a variety of unique problems that exist in the world of wireless networks.
Types of Wireless Networks
Just as cable-based network, the wireless network can be classified into several different types based on the distances over which data can be transmitted.
Wireless Wide Area Networks (WWANs)
WWAN technology enables users to establish wireless connections over public or private networks. This connection can be made covering a very wide area, like a city or a country, through the use of multiple antennas or satellite system also organized by telecommunications service providers. WWAN technology currently known as 2G systems (second generation). The core of this 2G systems include the Global System for Mobile Communications (GSM), Cellular Digital Packet Data (CDPD) and Code Division Multiple Access (CDMA). Various efforts are being made to transition from 2G technology to 3G (third generation) that will soon become a global standard and has global roaming feature also. ITU is also actively involved in promoting the manufacture of a global standard for 3G technology.
Wireless Local Area Networks (WLANs)
WLAN technology allows users to build a wireless network in a localized area (for example, within an office building environment, campus buildings or in public areas, such as airports or cafes). WLAN can be used in temporary offices or where permanent wiring installation is not allowed. Or WLAN sometimes constructed as a supplement to the existing LAN, so users can work on a variety of different locations within the building. WLAN can be operated in two ways. In infrastructure WLANs, wireless stations (devices with radio network cards or external modems) connected to a wireless access point that serves as a bridge between the stations and the network backbone available at that time. In WLAN environments that are peer-to-peer (ad hoc), multiple users within a limited area, such as meeting rooms, can form a temporary network without using an access point, if they do not need access to the resources the network.In 1997, IEEE 802.11 standard to approve for WLAN, which specifies the data transfer rate of 1 to 2 megabits per second (Mbps). Under 802.11b, which became the new standard are dominant today, data is transferred at a maximum speed of 11 Mbps over a frequency of 2.4 gigahertz (GHz). Other newer standard is 802.11a, which specifies the data transfer at a maximum speed of 54 Mbps over the 5 GHz frequency.
Wireless Personal Area Networks (WPANs)
WPAN technology allows users to build a wireless network (ad hoc) for simple devices, such as PDAs, cell phones or laptops. It can be used in the personal operating space (personal operating space or POS). A POS is a space that is around people, and can reach a distance of about 10 meters. Currently, two of the key WPAN technologies are Bluetooth and infrared light. Bluetooth is a cable replacement technology that uses radio waves to transmit data up to a distance of about 30 feet. Bluetooth Data can be transmitted through walls, pocket or purse. Bluetooth technology is driven by a body called the Bluetooth Special Interest Group (SIG), which publishes the Bluetooth specification version 1.0 in 1999 another alternative way to connect devices in very close proximity (1 meter or less), then the user can use infrared light. To standardize the development of technology WPAN, IEEE 802.15 working group has built for WPAN. The working group made a WPAN standard, which is based on the Bluetooth specification version 1.0. The main purpose of this standardization is to reduce complexity, low power consumption, interoperability and coexistence with 802.11 networks.

Minggu, 31 Agustus 2014

Wireless Fidelity

WiFi stands for Wireless Fidelity. WiFi is a wireless work tekologi that uses high frequency electromagnetic waves to transmit data. Frequency used by WiFi technology is at 2.3 GHz spectrum. By using WiFi, you can access the Internet quickly. WiFi has the ability to access the internet up to 11 Mbps or five times faster than the Internet access using 3G. Because the use of wireless, Wi-Fi technology utilized on a suitable location or runagan always be changed zoom. So that we can be the connected computer to the Internet using Wi-Fi, our computer must be equipped with a WiFi card or have support WiFi technology. Then we we are at locations where available WiFi signal or hotspot is often referred to as points or dots. Nowadays there are plenty of public places that has been providing services access internet connection using WiFi.
There are three components contained in a hotspot location, among others, is as follows:
1 Access Point (Access Point) is a device that connects to an Ethernet LAN Wireless technologies contained in the computer. The access point has to serve users as much as 128 people. The area can be reached by an access point to reach 25-100 meters.
2 Access Controller (access control) is a device that serves as a means of authentication, check whether a user is a person who has the right or permission to access.
3 Internet Link is a device that connects to the internet hotspot locations. Internet links have the ability to speed up internet connection of 512 kbps. Connection capability is used to serve all the users in one location.
The downside of internet access with WiFi access is only done at Dapa derah points as far as 100 meters from the point. And to date, only certain places are already installed point point. Certain places are usually a campus, hotels, cafes, airports, and other public places. Nowadays there are a lot of malls, cafes, hotels that provide internet access using WiFi for free. This is then used by many people for accessing the internet while hanging out with friends. Another drawback with internet access via WiFi is the issue of data security. Although the encrypted (encoded), the data submitted by over a data network easily penetrated.
wireless Broadband
Wi-Fi technology allows us to access the Internet at high speed. However, the condition we need to be in areas accessible WiFi signal. Limited area with WiFi signal and distance range of a WiFi signal is very short (about 100m) cause we can only use WiFi in certain areas only. Currently a new wireless technology being developed is called the Wireless Broadband (WiBro). However, this technology is still in the development stage and only used in a few countries and has not been marketed in Indonesia. Compared with WiFi, WiBro can be accessed from a distance of 1 kilometer from the point of access points with speed of 512 kbps. WiBro access can still be done from a moving vehicle at speeds up to 60 km / h.
3G 3G services can be obtained via the GSM and CDMA operators. In the GSM operators, 3G using WCDMA technology. The technologies of an evolution of GSM technology which then developed into GPRS. Later developed into GPRS EDGE (Enhanced Data rates for GSM Evolution) and WCDMA eventually become (3). While the CMA operator, 3G using EDV technology (Evolution Data Optimized). Technology is an evolution of the IS95 20001X (2.5G) developed into CDMA20001X EVDO (3G) and then became CDMA20001X EVDV (3G). The advantages of internet access using 3G, other than wide bandwidth, can also be supported with HSDPA (High Speed Downlink Packet Access). The technology allows Internet access at 2.6 Mbps or 40 times faster than Internet access by dial-up. The downside of the 3G technology is that we can only use limited to local outreach service provider. Far is the reach of 3G services is still very limited. 3G service operators, such as Indosat, Telkomsel and XL could bring new services in major cities in Indonesia alone and still dominated in Java. The 3G service operators still have to think twice to develop the service to other areas of its potentially small, because the investment costs incurred to build a huge infrastructure. This means derah other areas will still be a long reach by 3G services. The other drawback if you want to use the internet to access 3G services is the device used. If we want to access the internet using 3G services, we must have a cell phone equipped with 3G technology. whereas, a 3G mobile phone technology is still expensive. 3G network is not an upgrade from 2G; 2G operators affiliated with 3GPP need to replace a lot of components to be able to provide 3G services. While 2G operators affiliated with 3GPP2 technologies easier to upgrade to 3G because of its wide range of network elements in the direction it was designed for broadband wireless services (wireless broadband).

General Packet Radio Sevice

GPRS (General Packet Radio Sevice) is teknilogi sending data in packets by utilizing radio waves. GPRS is a wireless communication technology two and a half generation (2.5G) which is the development of technologies of GSM (2G). As wireless technology, we can utilize GPRS for accessing the internet anywhere as long as we are within range of a GPRS signal The need for mobile communication industry will lead into ne of the eknologi GPRS data communication is widely used this sat. GPRS has elajuan fast data transfer, which can reach 115kbps. Although in practice, the speed of GPRS data transfer is still in the 25-30 kbps.
In theory, GPRS promises speeds ranging from 56 kbps to 115 kbps, allowing internet access, multimedia data delivery to computers, notebooks and handheld computers.
However, in its implementation, it depends on the following factors:
• Configuration and allocation of time slots at the level of BTS
• Software used
• Support mobile phone features and applications that are used
Main Components
The main components of the GPRS network is:
• GGSN (Gateway GPRS Support Node): gateway GPRS network link to the Internet. The function of this component is the interface to the PDN (Public Data Network), information routing, network screening, screening user, address mapping.
• SGSN (Serving GPRS Support Node): BSS network connecting gate / BTS to the GPRS network. This component serves to deliver data packets to the MS, HLR updates to customers, new customer registration.
• PCU: BSS-level component that connects the terminal to the GPRS network
How it Works
SGSN in charge:
1 Send the packet to the Mobile Station (MS) in the area
2 Sending a number of questions to the HLR to obtain customer data profile (GPRS mobility management)
3 Detecting new MS-GPRS service in an area under their responsibility (location management)
4. SGSN is connected to the GSM BSS with Frame Relay connections through the PCU (Packet Control Unit) in the BSC
GGSN charge:
1 As an interface to external IP networks such as the public Internet or a mobile service provider
2 Updating the routing information from the PDU (Protocol Data Units) to the SGSN.
GPRS uses packet switch communication system as a way to transmit data. Packet switch is a system in which the data to be transmitted is divided into small parts (packets) transmitted and then the data is converted back to the original. The system can transmit thousands and even millions of packets per second. Transmission is done via (Public Land Mobile Network) by using an IP backbone. Because it allows for the use of the transmission channel PLMN simultaneously by other users, the cost of access to GPRS, in theory, cheaper than the cost of access to the CSD. GPRS is designed to provide the data packet transfer services on GSM networks at speeds better than GSM. Better speed is obtained by using a coding scheme (CS) which is different from GSM.

ADSL technology

A. Understanding the Internet
Internet comes from the Interconnected-networking that has meaning relationships with various types of computers that form a network system that covers the entire world (global computer network) by means of telecommunications such as telephone lines, radio links, satellite and others. In a set of computer network integration and communication protocol used is TCP / IP. TCP (Transmission Control Protocol) is tasked to ensure that all links are working properly, while the IP (Internet Protocol) which transmits data from one computer to lain.TP C / IP in general functions of data transmission choose the best route, an alternate route if a route can not be in use, manage and transmit the data packets delivery. To be able to come and use the facilities of the Internet, you usually have to subscribe to one of the SP (Internet Service Provider) that exist in your city. By utilizing the Internet, the use of computers across the world it is possible to communicate with each other and sharing information with each other how to send e-mail, connect to other computers, send and receive files, discuss a particular topic on the newsgroup and others.
B. Definition of intranet
An intranet is a private network (private network) that uses the Internet protocols (TCP / IP), to share confidential company information or operations of the company to its employees. Sometimes, the term intranet refers only to services that look, the company's internal Web site. To build an intranet, then a network must have some components that build the Internet, the Internet Protocol (TCP / IP, IP addresses, and other protocols), the client and the server. HTTP protocol and several other Internet protocols (FTP, POP3, or SMTP) protocol is generally a component that is often used. Generally, an intranet can be understood as a "private version of the Internet network", or as a version of the Internet that are owned by an organization.
INTERNET AND COMPUTER
The Internet is a very large computer networks. In order to connect to the network (the Internet), a computer requires hardware (hardware) additional. Once the hardware is met, our computer can be connected to the internet.
1 Computer Network (LAN)
Accessing the Internet using a local computer network is the computer connects to the internet via a local network server connected to the internet. Connecting internet via LAN were commonly done in many companies, laboratories, schools, Internet cafes, and so on. In order to access the internet via LAN, we use a computer should be connected in the network. To be able to connect the computer networks we must have a network card (LAN card). Gain access the internet via LAN is the cost for a cheaper internet access. This is due to the cost of computer access shared some fatherly. That is why the cost we spend for accessing the Internet from Internet cafes cheaper than the cost of access from home using telephone wires. The downside of internet access via LAN is if you're doing a lot access, access will be slow, especially if there is limited bandwidth.
Direct Telephone Line
Connecting a computer to the internet using the home phone line (dial-up) is the easiest way to access the internet. However, to do it we have to have a modem installed in a computer, phone line, and has signed up on a particular ISP. When we use the services of internet connection via dial-up, in addition to pay a subscription fee to an ISP, we also have to pay the cost of your telephone that we use every time we access the internet. Currently Telkom has been providing Internet access service called Instant TELKOMNet. These services allow us direct access to the internet without having to register first. Instant telkomnet using access number 080989999 with the user ID "telkomnet instant" and the password "telecom". These services can be used throughout Indonesia with the local telephone toll payment. When we use this service, internet access payments made will be charged to our phone payment each month. Access speeds by using a dial-up can reach 56 kbps. However, it is usually less than the maximum speed, especially if used telephone network is busy. Currently, some ISPs support dial-up service them with the data compression technology. The technology works by compressing data to be transmitted on the telephone line and then on the receiving side the data is returned (uncompress) again. This makes the data that must be passed in the telephone network becomes smaller, so that the data transmission becomes faster. Such technology can increase the data transfer speed to 4-5 times faster. The advantages of using the internet connection is dial-up network wide. Provided the phone is mounted, we can use this access. While the lack of dial-up access is still relatively expensive price, speed of access which is unstable and highly dependent on the load on the network telephone conversations, and mobility access requires that we remain on or place.

INTERNET AND COMPUTER
ADSL technology
Tenologi ADSL (Asymmetric Digital Subscriber Line) allows telephone lines are used to skip high kecpatan premises digital signal to transmit the data. This allows us are accessing the internet at high speed. Over telephone lines. ADSL technology provides advantages kapada Internet provider and also the customer. Service providers no longer need to build infrastructure to support ADSL service Bary. Customers certainly do not need to pay for the new infrastructure. Provided that no phone lines, ADSL services can be used. Connection to the Internet by using ADSL technology allows us to download data from the Internet more quickly and efficiently. ADSL is capable of transmitting data at speeds up to 2Mbps to users within 5 miles from the telephone exchange. Kelebhan other than a dialup connection, the connection to the internet will not be disturbed even though no incoming or outgoing call. Vice versa, the phone can still be entered even if the channel is being used for the Internet. In other words, we can still use the internet while using the phone simultaneously. This can not be done with dial-up connection.
In addition, the use of ADSL technology advantages are:
1 You can connect to the internet, and can still use the phone to receive / call.
2 speed is much higher than a regular modem.
3 Do not need a new phone cable, ADSL allows using existing telephone wiring.
4 Some ADSL ISP will provide ADSL modem as part of the installation.
The disadvantage of the technology is ADSL modem price is relatively more expensive compared to a modem for dial-up. In addition, the subscription price of the ADSL connection is still relatively expensive when it is used only for individuals. ADSL service is also not available in all regions, in addition, there are also other drawbacks are:
losses ADSL
1 ADSL connection will work perfectly if our location is quite close to the telephone exchange. At least within 2-3 km stretch of cable is usually quite safe to use ADSL to speeds around 8 Mbps. New DSL technology that can transmit data at speeds very height of up to 100 Mbps. Of course, for a very short distance.
2 ADSL connection is faster for receiving data than sending data over the internet.
3. old copper cable can degrade the quality of the connection and lower the speed.
4. no ADSL service area which no telephone wires. To be able to use ADSL, we have to provide an ADSL modem and is also listed as ISPs that provide customer connection services using ADSL technology.
Cable TV Network
Some cable TV companies also provide Internet access through cable TV networks. Internet access using cable TV network is the right choice for internet users within a family, where people can access the internet and keeping together. Cable TV networks were made for data communication lines wide. This is because the TV cable must pass data moving pictures and sound with high quality. If the internet is used for the size of the data that is passed only much smaller, we will get a very fast internet access. Typically, costs incurred for Internet access with cable TV service is bundled with cable TV. Therefore, the cable TV network users surf freely without having to add the cost of expenses. Excess use your network to access the Internet with cable TV is that we can access the internet at any time and free of distractions busy phone. The downside of intrnet access with cable TV network is only available in major cities and even then limited in certain areas are accessible by cable TV service.

Base Transceiver Station

1 Definition of BTS
BTS stands for Base Transceiver Station. This includes new terminology and became popular in the current era of mobile boom. BTS serves to bridge the communication device users with the network to other networks. One beam coverage base stations can be called a Cell. Modern cellular communication is communication that supports high mobility. Of some BTS then controlled by the Base Station Controller (BSC) which is connected to a microwave or fiber optic connections. Though the term BTS can be applied to any wireless communication standard, usually and commonly associated with mobile communication technologies such as GSM and CDMA. In this case, the base stations are part of the base station subsystem (BSS) developments for system management. It may also have equipment for encrypting and decrypting communications, spectrum filtering tools (band pass filter), etc. The antenna can also be considered as components of BTS in general sense as they facilitate the functioning of BTS. Usually BTS will have several transceivers (TRXs) which allow it to serve several different frequencies and different sectors of the cell (in the case of BTS sectorised). A BTS is controlled by a parent base station controller via the base station control function (BCF). BCF is implemented as a discrete unit or even incorporated in a TRX in compact base stations. The BCF provides operations and maintenance (O & M) connection to the network management system (NMS), and manages operational states of each TRX, as well as software handling and alarm collection. The basic structure and functions of the BTS remains the same regardless of the wireless technology.

2 Topology BTS
Base stations and mobile phones are equally called transceiver (BTS extension = Base Transceiver Station) because it is equally able to send information and receive information. At the time of sending information to mobile phone base stations, at the same phone can also send information to the base stations together properly when we chatted by phone we can talk simultaneously. In topology BTS serves to provide the network (interfaces) in the form of electromagnetic waves of radio signals for users in this case is the mobile phone, modem, fax, etc.. Frequency allocation has been followed by the government to each operator, there are in bands 450Mhz, 800Mhz, 900MHz, 1800 MHz and above that frequency. Communication from the BTS to the user is called the downlink, while the frequency bands that are used to send information from the user to the called BTS uplink
There are causes which made downlink frequency is higher than the uplink frequency, this corresponds to the power problem that must be provided by the user in this case is the mobile phone battery. In science the higher frequency of the disturbance (noise) will be greater, so that a greater power is required so that the quality is guaranteed. If the uplink frequency using a high-frequency mobile phone battery then the consequences could be more wasteful and quickly exhausted. The farther BTS mobile phone users to also affect the power requirement distance relationship is inversely proportional to the quality of the signal, the closer the distance the better the quality. Conversely the further distance diminishing its quality. The effect is what? if the quality of the signal received by the mobile phone base stations are declining, mobile phone base stations will be instructed to increase the transmission power, of course, would quickly run out of battery usage.
3 Component BTS
1) Tower Tower is a tower made of iron or pipe circuit either rectangular or triangular, or just a long pipe (stick), which aims to put the antenna and the radio wave transmitters and receivers of telecommunications and information. Tower BTS (Base Transceiver System) as a means of communication and informatics, in contrast with the tower SUTET (Air Line Extra High Voltage) Electric PLN in terms of construction, as well as the risk borne by the population below. BTS tower communication and informatics has a high degree of safety to humans and the creatures living on the bottom, because it has a very small radiation so it is safe for people under or around it.

Tower type this type are generally 3 types,
1) Tower with 4 legs, or large tower pipe (pipe diameter of 30 cm and above)
Tower with 4 legs is very rarely found collapsed, because it has the power poles and has considered construction. This type is expensive (650 million to 1 billion dollars), but strong and able to accommodate a lot of antenna and radio. Tower type is widely used by business firms bona fide communication and informatics. (Indosat, Telkom, XL, etc.).
2) Tower triangle which affirmed the stake rope.
Tower Triangle is advisable to wear an iron with a diameter of 2 cm and over. Several occurrences of this type of tower collapse due to wear iron with a diameter below 2 cm. The maximum height of tower type recommended is 60 meters. The average height is 40 meters. This type of tower composed of several stages (pieces). 1 stage there were 4 meters, but there are 5 meters. The shorter the stage the more sturdy, but the higher cost of manufacture, because each stage requires a rope stakes / spanner. Distance peg spanner with a tower of at least 8 meters. The longer the better, because it binds more robust, so that the amplifier cords are not more tapered at the top of the tower.
3) The iron pipe is reinforced with rope stake
The third type of tower is more likely to be used personally. Height of tower pipe is strongly recommended not to exceed 20 meters (more than it would be curved). Technical gains with a spanner. The strength of the pipe was resting on the spanner. Although still able to receive the signal connection, but the tower is not the type of receiver signal direkomedasi for informatics (internet and intranet) are stable, because the type is easily swayed and would disrupt the system data connections, so the computer will search for continuous data (searching). This tower can be built in the area close to the center of the transmission / NOC = Network Operation Systems (maximum 2 km), and do not have strong winds, as well as actually projected in the framework of emergency expenses. From the facts that appear in the various regions, where Tower has resistance / repulsion of the people, which caused health issues (radiation, anemia, etc.), safety issues to issues of social equity. It should need to be disseminated to the public that the first concern (health threats) is not proven. Verge much radiation tolerance limits set by WHO. Lowest BTS tower (40 meters) has a radiation 1 watt / m 2 (for aircraft with a frequency of 800 MHz) s / d 2 watts / m 2 (for aircraft 1800 MHz). While the standards issued by the WHO maximum tolerable radiation is 4.5 (800 MHz) s / d 9 watts / m 2 (1800 MHz). While the radiation from radio informatics / internet (2.4 GHz) is only about 3 watts / m 2 alone. Still very far from the WHO threshold of 9 watts / m 2. This radiation is weaker when the tower higher. Average cell tower built in Indonesia has a height of 70 meters. Thus the radiation is much smaller. As to the issue of life-threatening (eg, the collapse of the tower), can be overcome by the application of standard materials, and proper construction, and maintenance pewajiban each year. Components in the tower base stations:
Sectoral Antenna
The antenna is defined as a structure that serves as a release of electromagnetic wave energy in the air and also as a receiver / catcher electromagnetic wave energy in the air. Because an intermediary device between the transmission line and the air, the antenna must have the appropriate properties (match) with pencatu channel. The antenna is a device used to convert electrical signals into an electromagnetic signal and to radiate. Sectoral antenna is an antenna that transmits and receives signals in accordance with the angle of the transmit sector. The antenna used is a 3-sector antenna with a combination of Distributed Control System.

The microwave system is a system of transmitting and receiving microwave frequency is very high. The microwave system used for communication between the BTS or BTS-BSC.Microwave System that is used is the indoor system. But still attached microwave antenna tower. In antenna Microwave (MW) Radio, which looks like a tambourine drum, it includes the type of high performance antenna. Usually there are two brands, namely Andrew and RFS. The distinctive feature of this high performance antenna is shaped like a drum, and there is a lid, called a radome. Among other functions radome to protect the antenna components, from the surrounding climate change.

lightning rod
The lightning rod is a kind of circuit lines functioned as a way for the lightning to the earth's surface, without damaging the objects in its path.
lights
The lights are devices that can convert electrical energy into light energy. Lamps used for lighting around the neighborhood BTS
2) Shelter
BTS Shelter is a place that there are telecommunication devices. For location, usually will not be much of a Tower or Tower because of the dependence of a function between them, namely shelter and BTS Tower.
Components in the shelter:
At one shelter there are RBS and RBS 2G 3G, 1 RBS there are 6 and 1 TRU TRU 2 TRx there. TRx is a device that transmits and receives communication signals from / to the device mobile. TRx device consists of Transmitter and Receiver
transmission
Device used to regulate traffic on the slot BTS. connecting of TRx to boia is Processor BTS (Base band with the same shape, but has a connecting port for maintenance)
rectifier
Rectifier as a rectifier voltage of the AC voltage coming from PLN converted into DC voltage for consumption of other devices. There are 2 modules, each module supplies 30 Amperes, voltage used in the base stations is -48 Vdc
AC (Air Conditioner)
AC is a component / equipment used to regulate the temperature, circulation, humidity and air cleanliness in the room
PDB (Power Distribution Board)
Be a box containing MCB / power switches for each device
lights
For members lighting around the BTS.
Power Distribution Box

To distribute / distribute electrical current to the various components used in the BTS
Ground

serves to reduce or avoid hazards caused by lightning danger tinggi.misalnya voltage with high voltage
conclusion
Cellular technology is Wireless telecommunications system (without cable) that uses radio waves as its carrier signal with a hexagon-shaped cells, where the technology is on the BTS (Base Transceiver Station), the main component is that of the BTS tower and shelter where the two parts of the also has many components. In addition, BTS has different specifications and capacities in terms of the use of components and power he uses and we have tried to analyze the BTS, as explained above

Selasa, 26 Agustus 2014

cable networking

In computer networking technology, cable networking is the most important component in a network because he serves as a media liaison. In OSI Layer wires running / working on Layer 1 (Physical Layer). Copper cable consists of 4 types: UTP, STP, and coaxial ScTP
UTP: Unshielded Twisted Pair

UTP may be cited as the lowest category in the type of twisted pair cable. prior to the development of 10Base-T technology, UTP cable is unable to accommodate the data up to 10Mbps. UTP cable is now able to accommodate up to 100 Mbps of data. In July 1999, the IEEE approved standard for 1000Base-T UTP cable, UTP cable, which means the data can accommodate up to 1000 Mbps or Gigabit sized data.
UTP cable can be divided into several categories, namely:
Cat 1: working frequencies <1mhz communication="" eg="" for="" nbsp="" p="" telephone="">Cat 2: working frequency> 4 MHz, used on twisted pair ARCNET system and Apple LocalTalk
Cat 3: working frequency> 16 MHz, digunanakan at 4 Mbps UTP Token Ring, Ethernet 10Base-T, 100 Base-T4 and digital telephone system
Cat 4: working frequency> 20 MHz, used in 16 Mbps Token Ring LAN
Cat 5: working frequency of 100 MHz is used at 100 Mbps network
Cat 5e (enhanced): 5 categoti prepared to serve the data size gigabit
Cat 6: working frequency of 200 MHz, is used to serve data size gigabit
STP : Shielded Twisted Pair

STP was originally developed by IBM as horizontal cabling media. Compared UTP, STP is more resistant to interfence electromagnetic interference (EMI)
ScTP : Screened Twisted Pair

ScTP is the incorporation of UTP and STP technology. ScTP contains 4 pairs of wires 100 ohms. The cables and wires are protected layer of foil amplifier. ScTP also called foil twisted pair (FTP) for the use of this foil layer.
coaxial

Coaxial cable consists of several types, but has a uniformity of design. In the middle there is a single copper wire protected layer of PVC (polyvinyl chloride). These layers are wrapped stranded cable made of copper or aluminum. As the jacket cover rubber coated coaxial cable. Type coaxial cables in general are: RG-59: 75 ohms, for cable TV RG-58: 50 ohms, for thin ehernet RG-11: 50 ohms, for thick Ethernet
fiber Optics

Fiber optic cable is the latest generation of communications technology. This cable uses laser light as an information carrier wave. Optic cable has a service capacity which is much higher than copper wires. Optic cable can serve data up to 200Gbps!

Selasa, 03 Juni 2014

MTA

The e-mail server operates two separate processes: Mail Transfer Agent (MTA) Mail Delivery Agent (MDA) The Mail Transfer Agent (MTA) process is used to forward e-mail. As shown in the figure, the MTA receives messages from the MUA or from another MTA on another e-mail server. Based on the message header, it determines how a message has to be forwarded to reach its destination. If the mail is addressed to a user whose mailbox is on the local server, the mail is passed to the MDA. If the mail is for a user not on the local server, the MTA routes the e-mail to the MTA on the appropriate server. In the figure, we see that the Mail Delivery Agent (MDA) accepts a piece of e-mail from a Mail Transfer Agent (MTA) and performs the actual delivery. The MDA receives all the inbound mail from the MTA and places it into the appropriate users' mailboxes. The MDA can also resolve final delivery issues, such as virus scanning, spam filtering, and return-receipt handling. Most e-mail communications use the MUA, MTA, and MDA applications. However, there are other alternatives for e-mail delivery. A client may be connected to a corporate e-mail system, such as IBM's Lotus Notes, Novell's Groupwise, or Microsoft's Exchange. These systems often have their own internal e-mail format, and their clients typically communicate with the e-mail server using a proprietary protocol. The server sends or receives e-mail via the Internet through the product's Internet mail gateway, which performs any necessary reformatting. If, for example, two people who work for the same company exchange e-mail with each other using a proprietary protocol, their messages may stay completely within the company's corporate e-mail system. As another alternative, computers that do not have an MUA can still connect to a mail service on a web browser in order to retrieve and send messages in this manner. Some computers may run their own MTA and manage inter-domain e-mail themselves.

As mentioned earlier, e-mail can use the protocols, POP and SMTP (see the figure for an explanation of how they each work). POP and POP3 (Post Office Protocol, version 3) are inbound mail delivery protocols and are typical client/server protocols. They deliver e-mail from the e-mail server to the client (MUA). The MDA listens for when a client connects to a server. Once a connection is established, the server can deliver the e-mail to the client. The Simple Mail Transfer Protocol (SMTP), on the other hand, governs the transfer of outbound e-mail from the sending client to the e-mail server (MDA), as well as the transport of e-mail between e-mail servers (MTA). SMTP enables e-mail to be transported across data networks between different types of server and client software and makes e-mail exchange over the Internet possible. The SMTP protocol message format uses a rigid set of commands and replies. These commands support the procedures used in SMTP, such as session initiation, mail transaction, forwarding mail, verifying mailbox names, expanding mailing lists, and the opening and closing exchanges.

Some of the commands specified in the SMTP protocol are:

HELO - identifies the SMTP client process to the SMTP server process
EHLO - Is a newer version of HELO, which includes services extensions
MAIL FROM - Identifies the sender
RCPT TO - Identifies the recipient
DATA - Identifies the body of the message

SMB

The Server Message Block (SMB) is a client/server file sharing protocol. IBM developed Server Message Block (SMB) in the late 1980s to describe the structure of shared network resources, such as directories, files, printers, and serial ports. It is a request-response protocol. Unlike the file sharing supported by FTP, clients establish a long term connection to servers. Once the connection is established, the user of the client can access the resources on the server as if the resource is local to the client host. SMB file-sharing and print services have become the mainstay of Microsoft networking. With the introduction of the Windows 2000 series of software, Microsoft changed the underlying structure for using SMB. In previous versions of Microsoft products, the SMB services used a non-TCP/IP protocol to implement name resolution. Beginning with Windows 2000, all subsequent Microsoft products use DNS naming. This allows TCP/IP protocols to directly support SMB resource sharing, as shown in the figure. The LINUX and UNIX operating systems also provide a method of sharing resources with Microsoft networks using a version of SMB called SAMBA. The Apple Macintosh operating systems also support resource sharing using the SMB protocol.

The SMB protocol describes file system access and how clients can make requests for files. It also describes the SMB protocol inter-process communication. All SMB messages share a common format. This format uses a fixed-sized header followed by a variable-sized parameter and data component. SMB messages can:

LAN (Local Area Network)

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