Members:Jorge Cassiano
e-mail : [email protected]Lisa Ying
e-mail : [email protected]Kai Yee Luk
e-mail : [email protected]Hendry Kosasih
e-mail : [email protected]Mulyawati Konggidnata
e-mail : [email protected]
The basic Network Topology
Each computer network can be classified into one of few basic categories, depending on its topology. It is important to know how specific technologies are similar and how they differ. To help understand similarities each network is classified into a category according to its topology or general shape. Which are mesh topology, star topology, bus topology, tree topology, ring topology, star-wired topology, and star-wired ring.
In a mesh topology, each device is connected by a cable to every other device in the network. This may be convenient for small network, but become awkward and expensive as the network grows to more than a few devices.
Fig. Mesh topology
In a star topology, all devices are connected by cable to a single central point some type of controller is located at this central point; because a star-shaped network resembles the spokes of a wheel, the center of a star network is often called a hub. A typical hub consists of an electronic device that accepts data from a sending computer and delivers it to the appropriate destination. instead, a hub is located an equal distance from all computer attached to it. The centralized control requirement is often-cited disadvantage of star network in a star network. All data is routed through the central point.
Fig. Star topology
A network that uses a bus topology usually consist of single, long cable to which computer attach. Any computer attached to a bus can send a signal down the cable, and all computers receive the signal. Because all computers attached to the cable can sense an electrical signal, any computer can send data to any other computer. Of course, the computers attached to a bus network must coordinate to ensure that only one computer send a signal at any time or chaos results.
Fig. Bus topology
(Shared cable)
A Tree topology is similar to a bus network, except that there may be many different branches of the main bus. This allows many closely located devices to attach to the network with only single tap on the main bus. There is no central control point in bus or tree network, so new devices can be added by simply tapping onto the network at any point; disconnecting a tap removes a devices from the network. Every message placed on the bus travels past all users
Fig. Tree network
Ring topology consists of stations directly to each other by a single communication line. Message travel from station around the ring until it reaches its correct destination. As with the bus network, each station must capable of recognizing. It?s own address to receive a message. If a message is passed to a station, which is correct destination, the message is transmitted to the next station in the ring.
Fig. Ring network(Connection from one Computer to another)
In star-wired ring topology, a miniature bus is created inside the hub. Logically, the network is still bus, and the hub does not route the messages to any specific destination. Every message is sent to the hub, the hub the retransmits each message to every user, and user determines whether or not to read and process the message based address in the message header. This type of network physically connects the users to a central hub in a star configuration with either twisted pair, coax, or fiber optic cable.
Fig. Star-wired ring network
Communcations Media
The transmission media in common use in today?s data communication networks can be broken down into two major categories, conducted media include telephone and radiated. Conducted media include coaxial (coax), fiber optic, unshielded twisted pair (UTP), and shield twisted pair. In the radiated media, there are 2 major types of transmission include microwave radio transmission, and satellite transmission. In here we would like to focuses on those characteristics that make each medium desirable or undesirable in the different situations, including speed, distance, cost.
Coaxial Cable
Coaxial cable is primarily utilized in local area network or relatively short distances, generally less than 10 miles (except for uses by common carriers). (A local are network (LAN) typically is privately owned and restricted to a relatively small geographical area such as an office building or complex of buildings. Coaxial cable is also used to connect terminals with terminal controller unit. Data transmission bit rate is in excess of 400 Mbps, the cost coaxial cable ranges from approximately 65 cents per foot to several dollars per foot. Other major cost items in coaxial network are the adaptors, controllers, and transceivers that transmit and receive data at high speed.
Fiber Optic Cable
Fiber optics is a fairly new communications medium. It is used by telephone companies in place of long-distance wires as well as private companies in implementing local data communications networks. Fiber optic cables is a popular high bandwidth transmission medium. Data is transmitted by shining a light through a special type of glass fiber. Fiber optic transmission is a modern day form of the signal lights used to transmit information between ships at sea. Fiber optic cable has the ability to transmit signals over much longer distances than coaxial cable and twisted cable. The data rates can exceed 2400 Mbps, this capacity broadens communication possibilities to include services such as video conferencing and interactive services.
Fiber optics cable is far more expensive per foot than coax or twisted pair, but the high bandwidth can still make fiber optics economical for high volume applications. The cost of installing fiber optic is also high, with connections costing far more than coax or twisted pair; special equipment and training are required.
Unshielded Twisted Pair (UTP) cable
Unshielded Twisted Pair (UTP) is the most popular and is generally the best option for school or office networks. The quality of UTP may vary from telephone-grade wire to extremely high-speed cable. The cable has four pairs of wires inside the jacket. Each pair is twisted with a different number of twists per inch to help eliminate interference from adjacent pairs and other device. There are 5 categories of wire.
Type
Category 1 Voice Only (telephone wire)
Category 2 Data to 4 Mbps (local talk)
Category 3 Data to 10 Mbps (ethernet)
Category 4 Data to 20 Mbps (16 Mbps token ring)
Category 5 Data to 100 Mbps (Fast Ethernet)
One different between categories of UTP is the tighness
of the twisting of the copper pairs. The tighter the twisting, the higher
the supported transmission rate and the greater the cost per foot.
Shielded Twisted Pair (STP) Cable
Shielded Twisted Pair (STP) is suitable for environment with electrical interference; however the extra shielding can make the cables quite bulky. The transmission was rated 16 MHz. Shielded twisted pair is often used on networks using Token Ring topology.
Satellite Transmission
Satellite transmission uses radio waves to transmit data. A satellite dish, or antenna, known as the unlink station, transmits data to the satellite, which orbits the earth. Transponders on the satellite then repeat the signal, which is received by another satellite dish, known as the downlink station. Satellites typically orbit approximately 22,500 miles above the earth?s surface ; any satellite dish pointed at the satellite can receive the signal provided that it is tuned to the proper frequency, much the way we tune in radio station. The bandwidth transmission depends on the equipment used in the uplink and downlink stations and the number of satellite channels used; each satellite is capable of handing many channels at one time, each of different transmission frequencies . Satellite bandwidth can extend from 64 kbps to many Mbps, and almost unlimited if enough channels are used. Satellite transmission is usually cheaper over long distances than fiber optics or twisted pair; because there is no cabling cost between the two locations.
Microwave Transmission
Terrestrial microwave transmission uses radio frequencies
similar to those found in satellite transmission. Instead of bouncing radio
waves off a satellite, the users build tall towers and point the dishes
at each other. Alternatively, the dishes can be put on the top of building,
as long as there is a clear line of sight between the two dishes. The signals
used for microwave transmission can be sent only 20 to 30 miles. Longer
distances require using multiple hops, with additional towers in between.
Microwave transmission bandwidth can exceed 250 Mbps.
The key difference between microwave transmission and
satellite transmission is that microwave transmission requires a line of
sight between the two dish antennas. There can be no obstruction between
the two antennas.
Advantages and disadvantages of the Topology
Linear Bus
A linear bus topology consist of main run of cable with a terminator at each end. All nodes (file server, workstations, and peripherals) are connected to the linear cable. Ethernet and local talk networks use a linear bus topology.
Advantages of a linear Bus topology
A star topology is designed with each node (file server, workstations, and peripherals) connected directly to a central network hub or concentrator. Data on a star passes through the hub or concentrator of the network. It also acts as a repeater for the data flow. This configuration is common with twisted pair cable; however, it can also be used with coaxial cable or fiber optic cable. The protocols used with star configurations are usually Ethernet or LocalTalk. Token Ring uses a similar topology, called the star-wired ring.
Advantages of star topology
A tree topology combines characteristic of linear bus and star topologies. Its consists of groups of star-configured workstations connected to linear bus backbone cable. Tree topologies allow for the expansion of an existing network, and enable schools or office to configure a network to meet their needs.
Advantages of a tree topology
A star-wired topology may appear (externally) to be the same as a star topology. Internally, the MAU ( multistation access unit) of a star-wired ring contains wiring that allows information to pass from one device to another in circle or ring. The advantages of this topology are even the cable is cut, the network still can be transmitted because there is backup line and transfer the data also can be faster because from one node to other node. Disadvantages : expensive to build and it could be a bit expensive to install.
Mesh
The mesh topology, the expandability of interconnected configurations ranges from terrible to good, depending on where the new node is inserted. In a fully interconnected network, expansion is costly and time-consuming because a link must be established to every node with which the new node must communicate.
Advantages of mesh topology
The typical ring configuration has data flowing in one direction around the ring. Especially true in local area networks.
Advantages of ring topology
The choice of topology depends on a variety of factors, including
reliability, expandability, and performance. This choice is part of the
overall task of designing a local network, the Bus topology appears to
be the most flexible one to use in two storey building (medical center).
It is able to handle a wide range of devices, in terms of number of devices,
and data type. With the bus topology, the communication network is simply
the transmission medium - no switches and no reapeters. All station attach,
through approriate hardware interfacing directly to a linear transmission
medium or bus. A transmission from any station propagates the length or
medium can be received by all other station. Therefore we can consider
thourgh advantages and disadvantages. Reliable and bus network is good,
unless the buss itself fails. The loss of one node has no effect on any
of the othernode. High Bandwidth is achievable, because the medium is passive.
it would appear at first blush to be highly reliable. In particular a break
in the cable can disable a large part or all of the network. However the
main line can be protected or shielded, to avoid a breakdown in the main
cable. Comparing the other topology, bus is the better one because the
other topology more worse can be happended. In other hand bus topology
is suitable and more efficient to use in this medical center building.
So in my conclusion about installation the topology, i would like to recommend
to use bus topology.
Wiring options, advantages and disadvantages
A chart summarizing the different transmission media, and their advantages
and disadvantages.
| Type
|
Advantages
|
Disadvantages
|
| Coaxial cable | Shielded | Bulky and somewhat inflexible |
| Fairly inexpensive | ||
| Moderately high bandwidth | ||
| Fiber Optic cable | Transmission unaffected by noise | Expensive to install |
| Very high bandwidth | Repeaters often required | |
| UnshieledTwisted pair wire | Cost relative cheap | Doesn?t pass high frequencies well |
| Easy to install | ||
| Already installed in many locations. | ||
| Shielded Twisted Pair | Very inexpensive | Does not have a high bandwidth |
| Easy to install |
Recommandation :
Consideration of using media communication in the
To connect between medical center building to the hospital's network,
we might consider to use fiber optic cable. There are some consideration
why we might use fiber optic cable, through some benefit or advantages
and of course some disadvantages. However we might also compare with the
other media communication.
As we know the distance between 2 building arround 4 block away, fiber
optic cable already enjoys considerable use in long distance telecommunication.
Even long distance fiber optic cable can give greater bandwidth. The
potential bandwidth and hence data rate of medium increases with frequency.
At the immense frequencies of optical fiber data rates 2 Gbps over look
kilometers compare this to the practical maximum of hundreds of Mbps over
aboout 1km for coaxial cable and just a few Mbps over 1 km for twisted
pair. Electromagnetic isolation, optical fiber system are not effected
by external electronic fields. Thus, the system is not vulnerable to interference,
impulse noisemor crosstalk. Fiber do not radiate energy causing little
interference with other equipment and providing a high degree of security
from equesdropping; in addition, fiber is inherently difficult to tap.
Lower attenuation, attenuation is significantly lower for optical
fiber than for coaxial cable and twisted pair and is constant over a wide
range. About some disadvantages of fiber optica cable, fiber optic links
for very short distances cost more than wires; but as distance or required
transmission rate increase, fiber optic becomes cost effective. so the
fiber optic cable is the most suitable and effective to link up to medical
center building and hostpital's network.
Consideration of using media communication in the
The media communication to connect the floor and the other floor (
1st and 2nd floor), we might recommend using Ushielded twisted pair (UTP).
Unshielded twisted pair, or UTP, cable offers many adavantages over
the thickwire and thin coaxial cables, they are relatively expensive and
require some care during installation. UTP is similar to the telephone
cable that may already be installed in medical building. Unshielded twisted
pair cables come in a variety of gardes, with each higher grade offering
better performance. Level 5 cable is the highest, most expensive grade,
offering support for transmission ratess of up to 100 Megabits per second
(Mbps). Level 3 and 4 cables are less expensive but cannot support the
same data throughput speeds; level 4 cable can support speeds of up to
20 Mbps, level 3 upto 16 Mbps. Level 2 and Level 1 cables are the lowest
grades and are designed primarily for voice and low-speed transmission)
less than 5 Mbps; these might not be used to install in the medical center.
What we can see here is about the UTP cable that we also have to be considered.
The level 5 cables is the suitable one that we can used. Because the high
rates data transmission, so the transmission can be very good between the
1st floor and second floor also the transmission between workstation and
the other workstation.
RG59/62 Clamp |
RG58 Twist-on |
RG59/62 Crimp |
RG58 Crimp |
Some others connector used for Power User Connectors and NU data
Power User Connectors
The table price of thin coaxial
and twisted cable
Coax Cable
 |
Cable
Price
CABLE 50 FT THINNET
$21.99
CABLE 25 FT THINNET
$15.99
CABLE 10 FT THINNET
$10.99
CABLE 3 FT THINNET
$ 6.99
To estimate on bulk purchases (100 meters to 300 meters), for the thin coax cable. It might spend arround :$ 2292 ( CABLE 3 FT THINNET $ 6.99 x 300 meters)
note : 100 meters = 328 FT
Path Cable
 |
CABLE PATCH CAT 5 COLOR GRAY 100FT.
$29.99
CABLE PATCH CAT 5 COLOR GRAY 50FT.
$19.99
CABLE PATCH CAT 5 COLOR GRAY 2FT
$4.99
CABLE PATCH CAT 5 COLOR GREY 25FT
$14.99
CABLE PATCH CAT 5 COLOR GREY 20 FT
$12.99
CABLE PATCH CAT 5 COLOR GREY 14 FT
$9.99
Category 5 Patch Cable - 10 FT
$8.99
CABLE PATCH CAT 5 COLOR GREY 7 FT
$7.99
CABLE PATCH CAT 5 COLOR GREY 5 FT
$6.99
CABLE PATCH CAT 5 COLOR GREY 3 FT
$5.59
Category 5 Patch Cable - 1 Foot - Gray
$3.99
To estimate on bulk purchases (100 meters to 300 meters), for the path cable. It might spend arround :$ 3926 ( Category 5 Patch cable - 1 foot-gray = $ 3.99 x 300 meters)
note : 100 meters = 328 FT
For the using the connectors, RJ45 CAT 5 PLUG
W/TRIPOINT CONTACT UTP (50
PK) is high quality and very efficient. RJ 45 cat 5 plug is comformable
for unshielded twisted pair, in the otherhand the cable that we use to
install in the building is Unshielded twisted pair cable.
The cost would be $49.99/each, we would like to use arround 75 connectors
because in the medical center will have arround 70 workstations (35 workstation
in each floor). These worksations might need 70 conncectors and the other
5 connectors are to reserve. so $ 49.99 x 75 = $ 3749.25, this cost
will be spend for installing (connectors) the network in the
medical center.
TERMINATOR SCSI,MINI D68 INTERNAL ACTIVE
also is a good terminator. the cost might a bit high than the other terminator
($49.99). However this might not a big deal because these kind of
terminator can support the high transmission in the network, moreover the
transmission can be fast and more efficient.
Type of communication medium
to connect the floors of the building.
The choice of topology depends on a variety of factors, including reliability, expandability, and performance. This choice is part of the overall task of designing a local network, the Bus topology appears to be the most flexible one to use in two storey building (medical center). It is able to handle a wide range of devices, in terms of number of devices, and data type. With the bus topology, the communication network is simply the transmission medium.
The media communication to connect the floor and the other floor ( 1st
and 2nd floor), we might recommend using Ushielded twisted pair (UTP).
Unshielded twisted pair, or UTP, cable offers many adavantages over
the thickwire and thin coaxial cables, they are relatively expensive and
require some care during installation.
For the using the connectors, RJ45 CAT 5 PLUG W/TRIPOINT CONTACT UTP
(50
PK) is high quality and very efficient. RJ 45 cat 5 plug is comformable
for unshielded twisted pair, in the otherhand the cable that we use to
install in the building is Unshielded twisted pair cable.
TERMINATOR SCSI,MINI D68 INTERNAL ACTIVE also is a good terminator.
the cost might a bit high than the other terminator ($49.99). However this
might not a big deal because these kind of terminator can support
the high transmission in the network, moreover the transmission can be
fast and more efficient.
Fig. Connection between the floor using bus topology
Medical center
Connetion between two building
Consideration of using media communication in the 2 building ( medical
center and the hostpital).
To connect between medical center building to the hospital's network,
we might consider to use fiber optic cable. There are some consideration
why we might use fiber optic cable, through some benefit or advantages
and of course some disadvantages. However we might also compare with the
other media communication.
As we know the distance between 2 building arround 4 block away, fiber
optic cable already enjoys considerable use in long distance telecommunication.