CIS 505 Week 8 Discussions STR
Just Click on Below Link To
Download This Course:
https://bit.ly/2qk8N3p
CIS 505 Week 8 Discussions STR
CIS 505 Week 8 Discussion 1
The three mentioned satellites are used for
communications, whether marketable or in customary native groundwork is
inaccessible or capricious, circle in the earth in three orbits. Satellites are
used as a way to communicate around the globe. The broadcast industry as
well as the telecommunication companies and weather satellites uses GEO to
serve as its main access to communicate.
Geo configuration advantages are the
stationary relative to the earth which leaves no issues for frequency changes
due to the relative motion of the satellite and antennas on earth. Tracking is simplified
by earths stations. At 35,838 km above the earth, the satellite can
communicate with roughly one-fourth of the earth; three satellites in
geostationary orbit separated by 120x cover most of the inhabited portions of
the entire earth, excluding only the areas near the north and south poles.
LEO or the original AT&T satellite proposal was for
low earth orbititng satellites, but most of the early commercial satellites
were geostationary. The idea of LEO sattelites is to use constellations of
inexpensive. A LEO satellite can be “seen” by a point on earth on the
order of minutes before the satellite passes out of sight. If intermediate
orbits are used—higher than the LEOS and lower than GEOS—a point on earth can
see the satellite for periods on the order of hours. Such orbits are
called medium-earth-orbiting
satellites(MEOS).
These orbits are on the order of 10,000 km above the earth, and require fewer
handoffs. While propagation delay to earth from such satellites (and the power
required) is greater than for LEOS, they are still substantially less than for
GEOS. ICO Global Communications, established in January 1995, proposed a MEO
system. Launches began in 2000; 12 satellites, including two spares, are
planned in 10,400 km orbits. The satellites will be divided equally between two
planes tilted 45x to equator. Proposed applications are digital voice, data,
facsimile, high-penetration notification, and messaging services.
http://www.informit.com/articles/article.aspx?p=23761
http://www.harriscaprock.com/blog/high-throughput-satellite-communications-systems-meo-vs-leo-vs-geo/
“VSAT systems provide high speed, broadband
satellite communications for Internet or private network communications.
VSAT is ideal for mining camps, vessels at sea, satellite news gathering,
emergency responders, oil & gas camps or any application that requires a
broadband Internet connection at a remote location. VSAT is an excellent way to
connect your remote sites and workers with Internet communications for email,
web access, video transmissions, Voice over IP telephone services, or other IP
applications for your field operations. VSAT enables you to expedite your
business processes by integrating field operations with your corporate wide
area network.”
Coverage for the USA is on Galaxy 16, Galaxy
18 & AMC 9 satellites, provide options for connectivity across the USA. The
coverage at sea is Maritime VSAT services.
The business applications currently being
used to support VSAT is Television distribution, Long-distance telephone
transmission, and Private business networks. Because of their broadcast nature,
satellites are well suited to television distribution and are being used
extensively for this purpose in the United States and throughout the world. In
its traditional use, a network provides programming from a central location.
Programs are transmitted to the satellite and then broadcast down to a number
of stations, which then distribute the programs to individual viewers. A more
recent application of satellite technology to television distribution is direct
broadcast satellite (DBS), in which satellite video signals are transmitted
directly to the home user. GEOS (Geosynchronous Earth Orbit Satellites)
are used mainly for communications and broadcasts. Business applications could
be for satellite broadcasts, maritime phone calls, meteorological applications
and cable and satellite tv as well.
LEOS (Low Earth Orbit Satellites) are also
used in business for communications but on a more personal scale. LEOS are used
for email and mobile phone networks, video conferencing, high bandwidth data
connections and in government or business, can be used for spying and espionage
operations.
MEOS (Middle Earth Orbit Satellites) are used
in business for navigation. MEOS make up the backbone of the GPS enabled
applications that are out there.
VSAT (Very Small Aperture Terminals) is being
used to support businesses in a couple different ways. First, it allows for
businesses in remote locations to have access to Internet resources. Laying
cable is time consuming and very costly for rural areas. VSAT technology allows
businesses to remain competitive no matter where they are. VSAT allow for a
high QoS which allows them to be great partnered with VPN access for
businesses. The QoS is also improved because most VSAT connections are only
single hop resulting in less lag and loss.
References:
http://old.repertoiremag.com/Article.asp?Id=524
CIS 505 Week 8 Discussion 2
- Compare the four items related to channel capacity:
data rate, bandwidth, noise, and error rate. Determine the most important
and justify its significance over the remaining items.
- Describe real-world examples of attenuation and
white noise. Examine the effect on the information-carrying capacity of
the link and present a way to avoid these types of interruptions. Data
Transmission is the process of sending digital or analog data over a
communication medium to one or more computing, network, communication or
electronic devices. Data Rate is the term associated with the rate
of data transferred between two or more computing and telecommunication
devices or systems. Bandwidth is a wider term, which is basically
associated with the computer networking and digital technologies and
measures the bit rate of communication resources available or consumed.
Noise is unwanted electrical or electromagnetic energy that degrades the
quality of signals and data. Error rate is the degree of errors
encountered during data transmission over a communications or network
connection.
Noise is the most important component in the
channel capacity. Noise can disrupt the flow of information. There are so many
different types of noise one could face in a business setting: Environmental,
Physiological-Impairment, Semantic, Syntactical, Organizational, Cultural, and
Psychological. Issues in communications that
derives from the above mentioned noises could affect the sender, the message
itself, the channel it is being sent through, or the recipient of that message.
Attenuation is a loss of communication signal
strength measured in decibals (dB). Amplification is used to surge signal
potency. Range, Interference and Wire size are the reasons attenuation happens.
DSL uses attenuation. Typical values for line attenuation on a DSL connection
are between 5dB and 50dB.
White noise is a type of noise that is
produced by combining sounds of all different frequencies together.All the
imaginable tones the human ear can hear and combine them all together would
form white noise.White noise is random noise that has a flat spectral
density.The audible frequency range 20-20000 hertz. An example of white noise
is the sound of the ocean or the sound the train or subway makes as it moves
across the tracks. Ambulances, Fire Trucks or Police vehicles all use white
noise.The white noise is over heard through traffic and makes these emergency
vehicles more noticeable. When looking at the four items I would say that
error rate is the most important because it is great that you may get more
stuff transferred faster with less time but if it has a lot of errors in the
data then it is not as useful.
Techopedia explains Attenuation
Attenuation can relate to both hard-wired
connections and to wireless transmissions.
There are many instances of attenuation in
telecommunications and digital network circuitry.
Inherent attenuation can be caused by a number of signaling issues including:
Inherent attenuation can be caused by a number of signaling issues including:
- Transmission medium – All electrical signals transmitted down
electrical conductors cause an electromagnetic field around the
transmission. This field causes energy loss down the cable and gets worse
depending upon the frequency and length of the cable run. Losses due to
- Crosstalk from adjacent cabling causes attenuation in copper or
other conductive metal cabling.
- Conductors and connectors – Attenuation can occur as
a signal passes across different conductive mediums and mated connector
surfaces.
Repeaters are used in attenuating circuits to
boost the signal through amplification (the opposite of attenuation). When
using copper conductors, the higher the frequency signal, the more attenuation
is caused along a cable length. Modern communications use high frequencies so
other mediums which have a flat attenuation across all frequencies, such as
fiber optics are used instead of traditional copper circuits.
Different types of attenuation include:
- Deliberate attenuation can occur for example where a volume control
is used to lower the sound level on consumer electronics.
- Automatic attenuation is a common feature of televisions and other
audio equipment to prevent sound distortion by automatic level sensing
that triggers attenuation circuits.
- Environmental attenuation relates to signal power loss due to the
transmission medium, whether that be wireless, copper wired or fiber optic
connected.
- References
Comments
Post a Comment