STP VS UTP OF TWISTED PAIR

Twisted pair
Twisted pair cabling is a form of wiring in which two conductors (the forward and return conductors of a single circuit) are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation from Unshielded Twisted Pair (UTP) cables, and crosstalk between neighboring pairs

A)Unshielded Twisted Pair
Twisted pair cables were first used in telephone systems by Alexander Graham Bell in 1881. By 1900, the entire American telephone line network was either twisted pair or open wire with similar arrangements to guard against interference. Today, most of the millions of kilometres of twisted pairs in the world are outdoor landlines, owned by telephone companies, used for voice service, and only handled or even seen by telephone workers.
UTP cables are found in many ethernet networks and telephone systems. For indoor telephone applications, UTP is often grouped into sets of 25 pairs according to a standard 25-pair color code originally developed by AT&T. A typical subset of these colors (white/blue, blue/white, white/orange, orange/white) shows up in most UTP cables.
For urban outdoor telephone cables containing hundreds or thousands of pairs, the cable is divided into smaller but identical bundles. Each bundle consists of twisted pairs that have different twist rates. The bundles are in turn twisted together to make up the cable. Pairs having the same twist rate within the cable can still experience some degree of crosstalk. Wire pairs are selected carefully to minimize crosstalk within a large cable.Short for Unshielded Twisted Pair cable, UTP cable is a popular type of cable used in computer networking that consists of two shielded wires twisted around each other.

B)Shielded Twisted Pair
Shielded Twisted Pair Cable is used to eliminate inductive and capacitive coupling. Twisting cancels out inductive coupling, while the shield eliminates capacitive coupling. Most applications for this cable are between equipment, racks and buildings. Shielding adds usually some attenuation to the cable (compared to unshielded), but usually not because in the case of balanced transmission, the complementing signals will effectively cancel out any shield currents, so shield current losses are negligible.
The noise pickup characteritics of twisted pair cable is determined by the following cable characteristics: number of twists per meter (generally more twists per meter gives better performance), uniform cable construction, capacitance balance (less capacitance difference to groud, the better), cable diameter (less are between wires is better) and the amount of shielding (more shielding, the better).

ADVANTAGES AND DISADVANTAGES

(A)Twisted Pair
Advantages :
1. Cheaper and far easier to splice.
2. Less susceptible to electrical interference caused by nearby equipment or wires.
3. In turn are less likely to cause interference themselves
.4. Because it is electrically "cleaner", STP wire can carry data at a faster speed.
Disadvantages :
1. STP wire is that it is physically larger and more expensive than twisted pairwire.
2. STP is more difficult to connect to a terminating block.

(B)Coaxial Pair
Advantages :
1. Coaxial cable can support greater cable lengths between network devices than twisted pair cable.
2. Thick coaxial cable has an extra protective plastic cover that help keep moistureaway.
Disadvantages :
1. Thick coaxial is that it does not bend easily and is difficult to install.

(C)Fiber Optic
Advantages :
1. One single mode fiber can replace a metal of time larger and heavier.
2. Multi-mode optical cable has a larger diameter and can be used to carry signalover short distance.
Disadvantages :
1. Fiber optic versus metal cable is that it is difficult to make connections tofiber optic cable.
2. The optical fiber must be highly polished to allow light to pass with little loss.

B2B,B2C AND C2C..

B2B
B2B (business-to-business), also known as e-biz, is the exchange of products, services, or information between businesses rather than between businesses and consumers.
B2C
A transaction that occurs between a company and a consumer, as opposed to a transaction between companies (called B2B). The term may also describe a company that provides goods or services for consumers.
C2C
Consumer-to-consumer (C2C) (or citizen-to-citizen)electronic commerce involves the electronically-facilitated transactions between consumers through some third party. A common example is the online auction, in which a consumer posts an item for sale and other consumers bid to purchase it; the third party generally charges a flat fee or commission. The sites are only intermediaries, just there to match consumers. They do not have to check quality of the products being offered.

RADIO CORPORATION OF AMERICA(RCA)

RADIO CORPORATION OF AMERICA (RCA)
U.S. RADIO COMPANY

In 1919, General Electric (GE) formed a privately owned corporation to acquire the assets of the wireless radio company American Marconi from British Marconi. The organization, known as the Radio Corporation of America or RCA, was formally incorporated on 17 October of that year. Shortly thereafter, American Telephone and Telegraph (AT and T) and Westinghouse acquired RCA assets and became joint owners of RCA. In 1926, RCA formed a new company, the National Broadcasting Company (NBC), to oversee operation of radio stations owned by RCA, General Electric, Westinghouse and AT and T.
In the early 1930's, the Justice Department filed an antitrust suit against the company. In a 1932 consent decree, the organization's operations were separated and GE, AT and T, and Westinghouse were forced to sell their interests in the company. RCA retained its patents and full ownership of NBC. Shortly after becoming an independent company, RCA moved into new headquarters in the Rockefeller Center complex in New York City, into what later became known as Radio City.
While other American companies were cutting back on research expenditures during the depression years, David Sarnoff, President of RCA since 1930, was a staunch advocate of technological innovation. He expanded RCA's technology research division, devoting increased resources to television technology. Television pioneer Vladimir Zworykin was placed in charge of RCA's television research division. RCA acquired competing and secondary patents related to television technology, and once the organization felt that the technology had attained an appropriate level of refinement, it pushed for commercialization of the new medium.
In 1938, RCA persuaded the Radio Manufacturers Association (RMA) to consider adoption of its television system for standardization. The RMA adopted the RCA version, a 441 line, 30 pictures per second system, and presented the new standard to the FCC on 10 September 1938. Upon the recommendation of the RMA, the Federal Communications Commission (FCC) scheduled formal hearings to address the adoption of standards. The hearings, however, did not take place until January 1940.
In the interim, RCA began production of receivers and initiated a limited schedule of television programming from the New York transmitters of the National Broadcasting Corporation (NBC) basing their service upon the RMA-RCA standards. The service was inaugurated in conjunction with the opening of the New York World's Fair on 30 April 1939 and continued throughout the year. At the commission's hearing addressing standards on 15 January 1940, opposition to the proposed RMA standards emerged. The two strongest opponents of the standard were DuMont Laboratories and Philco Radio and Television. One of the criticisms voiced by both organizations was the assertion that the 441 line standard did not provide sufficient visual detail and definition. Given the lack of a clear industry consensus, the Commission did not act on the proposed RMA standards. Despite the absence of official approval, RCA continued to employ the RMA standards and announced plans in early 1940 to increase production of television receivers, cut the price to consumers by one-third, and double their programming schedule. While some commentators saw this as a reasonable and progressive action, the Commission perceived it as a step towards prematurely freezing the standards in place, and as a consequence, scheduled another set of public hearings for 8 April 1940. At these hearings, opponents argued that the action taken by RCA was stifling research and development into other alternative standards. As a result of the hearings, the Commission eliminated commercial broadcasting until further development and refinement had transpired. Furthermore, the Commission asserted that commercialization of broadcasting would not be permitted until there was industry consensus and agreement on one common system. To marshal industry wide support for a single standard, the RMA formed the National Television System Committee (NTSC). The NTSC standards, a 525 line, 60 fields per second system, were approved by the FCC in 1941.
Several years later, RCA also became a major participant in the establishment of color television standards. In 1949, the organization proposed to the FCC that its dot sequential color system, which was compatible with existing black and white receivers, be adopted as the new color standard. Citing shortcomings in the compatible systems offered by RCA and other organizations, the FCC opted to formally adopt an incompatible color system offered by the Columbia Broadcasting System as the color standard. RCA appealed this decision all the way to the Supreme Court, while simultaneously refining their color system. A second NTSC was formed to examine the color issue. In 1953, the FCC reversed itself and endorsed a modified version of the RCA dot sequential system compatible color system offered by the NTSC.
In the 1950s, RCA continued the military and defense work in which it had been heavily engaged during World War II. In the late 1950s and early 1960s, the company became involved with both satellite technology and the space program. During the 1960s, RCA began to diversify as the company acquired such disparate entities as the publishing firm Random House, and the car rental company Hertz. Throughout the 1970s and early 1980s, RCA began to divest itself of many of its acquired subsidiaries. In June 1986, RCA was acquired by General Electric, the organization that had originally established it as a subsidiary. GE retained the brand name RCA, established NBC as a relatively autonomous unit, and combined the remainder of RCA's businesses with GE operations.

10 SHORT FORM SMS

10 short form sms
1)You-u
2)Because-bcoz
3)Maybe-myb
4)The-da
5)Just-juz
6)Friend-fren
7)With-wif
8)good night-gud nite
9)love-luv
10)miss-miz

TREE TOPOLOGY AND MESH TOPOLOGY

TREE TOPOLOGY
Also known as a star bus topology, tree topology is one of the most common types of network setups that is similar to a bus topology and a star topology. A tree topology connects multiple star networks to other star networks. Below is a visual example of a simple computer setup on a network using the star topology.

In the above example picture if the main cable or trunk between each of the two star topology networks failed, those networks would be unable to communicate with each other. However, computers on the same star topology would still be able to communicate with each other.

MESH TOPOLOGY

Mesh Network is a network where all the nodes are connected to each other and is a complete network.In a Mesh Network every node is connected to other nodes on the network through hops.Some are connected through single hops and some may be connected with more than one hope.While the data is travelling on the Mesh Network it is automatically configured to reach the destination by taking the shortest route which means the least number of hops.Data travels by hopping from one node to another and then reaches the destination node in a Mesh Topology Network.An example of a Mesh Network is the Mobile Adhoc Network or MANet.The entire Mesh Network is continuously connected.Being completely connected does not mean that Mesh Network is dependant on each and every node of the network.Even if one node fails in the Mesh Network the network finds an alternate route to transfer the data.It is called the self healing technology where it receives data one way or the other.The Mesh Network is based on a very sensible concept and has lesser chances of a network breakdown.There are so many possible combinations of routes and hops a data transfer can take that it will reach the destination one way or the other.It is highly unlikely that all the nodes in a single Mesh Network will break down at any given point of time.WIRELESS MESH NETWORKSWireless Mesh Network will work based on the radio frequencies and was originally developed by the army to be able to communicate.The reliability factors is high in any kind of Mesh Network.There are three types of wireless Mesh Topologies.
1.Fixed Wireless Connections
2.Peer to Peer or Adhoc Networks
3.Node to Node

FIXED MESH NETWORK
the fixed Mesh Networks will work only in the specified location and they are not mobile networks.They are meant to be used in a limited surrounding with boundaries.The location of nodes in affixed Mesh Network is all pre determined and they are not interchangeable.The fixed Mesh Network does not work on line of sight like the other types of Mesh Network.The total number of hops in a fixed Mesh Network is usually fixed and also short.There may not be many nodes as this kind of Mesh Networks exist within an office or building.More often than not the data travels on a specific direction

PEER TO PEER MOBILE NETWORKS
in a peer to peer mobile network the individual devices connect to each other using the Mesh Network.The peer does not require connecting to the main node and they can still communicate from one device to another device by taking the shortest possible data transfer route.However many experts believe that in peer to peer Mesh Networks the problems with scalability in terms of time taken for data transfer is questionable.The device has to know to transmit the data in the most optimal path and the entire data transfer or depends on this single factor.If the device is incapable then the whole purpose of using it in a peer to peer connection is lost

NODE-TO-NODE NETWORK
a Node-To-Node network is a combination of fixed Mesh Network and the mobile Mesh Network.In the node to node network a network cloud is introduced and all the nodes are configured to use the network cloud to connect to each other.So this feature makes it mobile and also the network is fixed because all the nodes of the same network connect to one single network cloud

razak SAT

RazakSAT Launching

We always talk of politics and political debates… this time VOY would like to write a bit about the nation’s latest achievement. The nation’s second micro satellite, the RazakSAT will we launched on 21 April from the Kwajelein Launch Facility in the Marshal Islands.
The satellite will be launched using the Falcon-1 from SpaceX which is based in the United States. The project of launching the satellite has been organized by Astronautic Technology (M) Sdn Bhd (ATSB).
Alongside RazakSAT the government will also be launching two more mini satellites which are the CubeSAT and InnoSAT. Both of them are new technology introduced by ATSB to ensure the stability of the satellites while in space.
“RazakSAT is the first satellite to have remote sensing with the total cost for the construction and launching of the satellite totaling RM150 million and will benefit not only our country but also the whole along the whole Equator.
“InnoSAT is the for project to combine the collaboration of university and industry in producing a satellite on the government’s research tender through the Science Fund as the government’s effort to produce experts in this field,” said Fadillah Yusof,
RazakSAT was actually scheduled to be launched early last year but was postponed as there were no available launch slots. ATSB is the leading company in satellite research in Malaysia, and was responsible for the construction of the Malaysian Tsunami Early Warning System, and the operation of the nation’s first microsatellite, the TiungSAT-1.
Another achievement by the nation that should be applauded and make the people of Malaysia proud. Some time we get sick and tired of news about political conflicts that is always in the news that we forget the achievement of our nation. At least there are still those concerned with the development of the nation. Let’s hope there are many more of such achievement in the future.
Blogger,voice of youth(2009)http://www.voy.com.my/archives/365