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Definition - What does Nomadic Computing mean?
Nomadic computing is the use of mobile computing technology to connect to the
global Internet or use specific data resources from a stored location while moving
around from one place to another.
The phenomenon of nomadic computing relies on a number of key innovations that
have allowed people around the world to access shared resources from nearly
anywhere. These include the emergence of the global Internet as well as advances in
storage media, server design, and encryption and security protocols for remote access.
Nomadic computing is also known as mobile computing.
Cloud computing is a general term for anything that involves delivering
hosted services over the Internet. These services are broadly divided into
three categories: Infrastructure-as-a-Service (IaaS), Platform-as-a-Service
(PaaS) and Software-as-a-Service (SaaS). The name cloud computing was
inspired by the cloud symbol that's often used to represent the Internet in
flowcharts and diagrams.
x-tics of mobile computing devices
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Portability: Facilitates movement of device(s) within the mobile computing environment.
Connectivity: Ability to continuously stay connected with minimal amount of lag/downtime,
without being affected by movements of the connected nodes
Social Interactivity: Maintaining the connectivity to collaborate with other users, at least within
the same environment.
Individuality: Adapting the technology to suit individual needs.
Limitations
Expandability and Replaceability: In contrast to the common traditional motherboard-based PC
the SoC architecture in which they are embedded makes impossible these features.
Lack of a BIOS: As most smart devices lack of a proper BIOS they're bootloading capabilities are
limited, as they can only boot into the single operative system with which it came, in contrast with the
PC BIOS model.
Range and bandwidth: Mobile Internet access is generally slower than direct cable connections, using
technologies such as GPRS and EDGE, and more recently HSDPA, HSUPA, 3G and 4G networks and
also the proposed 5G network. These networks are usually available within range of commercial cell
phone towers. High speed network wireless LANs are inexpensive but have very limited range.
Security standards: When working mobile, one is dependent on public networks, requiring careful use
of VPN. Security is a major concern while concerning the mobile computing standards on the fleet. One
can easily attack the VPN through a huge number of networks interconnected through the line.
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Power consumption: When a power outlet or portable generator is not available, mobile
computers must rely entirely on battery power. Combined with the compact size of many mobile
devices, this often means unusually expensive batteries must be used to obtain the necessary
battery life.
Transmission interferences: Weather, terrain, and the range from the nearest signal point can all
interfere with signal reception. Reception in tunnels, some buildings, and rural areas is often
poor.
Potential health hazards: People who use mobile devices while driving are often distracted from
driving and are thus assumed more likely to be involved in traffic accidents.[1] (While this may
seem obvious, there is considerable discussion about whether banning mobile device use while
driving reduces accidents or not.[2][3]) Cell phones may interfere with sensitive medical devices.
Questions concerning mobile phone radiation and health have been raised.
Human interface with device: Screens and keyboards tend to be small, which may make them
hard to use. Alternate input methods such as speech or handwriting recognition require training.
Advantages & Disadvantages of a
Mobile IP
Uniqueness
A mobile IP address allows users to connect to the Internet without a normal static or
dynamic IP address through the use of a unique mobile IP address. This unique
address lets the computer connect through a network to a home IP address but still
utilize and communicate with the network's protocol. Having a unique IP is important for
routing information to the correct computer. In short, if it were not for mobile IPs,
information would continue to be routed to the last known IP address at which that
computer was located, and a seamless connection would be impossible.
Portability
IP creation on the go is the only way that users can access the Internet while away from
a traditional modem/router setup. Mobile IP addresses create a tunnel to a host server,
which allows an access point to the Internet from any location where a signal can be
received. Mobile IPs can create connection protocols to connect to the Internet through
multiple servers and networks. A mobile IP address allows users to roam through
multiple networks and maintain an IP address. This option is useful for employees who
travel throughout a building and cross into multiple wireless zones.
Spotty Internet Availability
Spotty Internet availability is still something that plagues mobile users. A mobile IP
requires a strong signal to connect to the Internet. In major metropolises, signals are
easily obtained, and a mobile IP will be able to roam between networks with little
problem at all. In many urban areas, however, coverage is still sparse, and strong
signals are difficult to come by. In general, the stronger the signal, the faster and more
reliable the connection will be. In the case of a weak signal, it is typical for the
connection to be slow and unstable.
VoIP (Voice over Internet Protocol) is simply the transmission of voice traffic
over IP-based
networks
.
The Internet Protocol (IP) was originally designed for data networking. The success of IP in
becoming a world standard for data networking has led to its adaptation to voice networking.
Some background history:
Although VoIP has been creating quite a stir in the press recently, it’s actually not a new idea
at all. VoIP has been around in one form or another since 1973 when it began as an
experiment by the US Department of Defense.
Why VoIP is better ?
VoIP has become popular largely because of the cost advantages to consumers over
traditional telepone networks. VoIP slashes your monthly phone bill by a whopping fifty
percent.
Let's
put
some
light
over
these
claims.
It offers cheaper international long distance rates which are generally one-tenth of what is
charged by traditional phone companies. Its portability makes it a very good option and one
could avoid expensive hotel phone charges and cell phone roaming charges. What one
requires is just a high speed connection where one could plug the adapter into and people
could reach you at your local number irrespective of your location.
Most Internet connections are charged using a flat monthly fee structure. Using the Internet
connection for both data traffic and voice calls can allow consumers to get rid of one monthly
payment. In addition, VoIP plans do not charge a per-minute fee for long distance.
By making VoIP calls using internet enabled cell phones one could avoid wireless roaming
fees and long distance rates which generally touch north. Most of the times in-network calls
to other VoIP service subscribers are free even if the calling parties are located in different
parts of the world.
How does it work?
Just to confuse people, there are many kinds of VoIP. Using voice chat in MSN , G Talk or
Yahoo messenger could be regarded as VoIP, so could the highly publicised Skype; but these
are all proprietary systems. To talk to someone using MSN, the person at the other end also
needs MSN. The same applies to Yahoo and, to a great extent, to Skype. They use their own
special system that isn't open and won't connect to other systems easily.
True VoIP should really be based on the SIP system which is the recognized standard. Any
SIP compatible device can talk to any other; you don't even use a PC. Any SIP telephone can
call another right over the internet, you don't need any additional equipment or even a phone
provider. Just plug your SIP phone into the internet connection, configure it and then dial the
other person right over the internet.
In all VoIP systems, your voice is converted into packets of data, like little files, and then
transmitted to the recipient over the internet and decoded back into your voice at the other
end. To make it quicker, these packets are compressed before transmission, a bit like zipping
a file.
Advantages of VoIP:
VoIP phone service providers offer many advantages to the residential and small office/home
office user. If you have a high speed internet connection then choosing a VoIP phone service
might be right for you.
Low Cost :
This technology leads to greater financial savings. This happens because there exists only one
network carrying the voice and data provided by only one supplier. If you have a broadband
Internet connection (DSL or cable), you can make PC-to-PC phone calls anywhere in the world
for free. If you wish to make a PC-to-phone connection, there's usually a charge for this but
probably much cheaper than your regular phone service.
You can pay as you go or you can sign up with a VOIP service provider and pay a monthly fee
in return for unlimited calls within a certain geographic area. For example, some VOIP services
in the United States allow you to call anywhere in North America at no extra charge.
Low Taxes :
Since the calls are being carried over the Internet, governments have not heavily taxed VoIP
phone services. Compare that to your local telephone bill (go ahead and take a close look)
and you will see you are spending quite a bit on taxes each month. Therefore, choosing a
VoIP provider could add up to significant savings for you and your family.
Portability :
One important concept to understand about VoIP is that unlike it’s forefathers (let’s call them
PSTN for now), it is not distance or location dependent. As far as VoIP is concerned, you could
be calling your supplier 1,000 miles away in Indonesia or calling your business partner on the
other end of town, and it doesn’t make any difference at all, in terms of connectivity and cost.
You can make and receive phone calls wherever there is a broadband connection simply by
signing in to your VoIP account. This makes VoIP as convenient as e-mail – if you are
traveling, simply pack a headset or Internet phone and you can talk to your family or business
associates for almost nothing.
No extra cables, no extra cost :
A VoIP phone number, unlike your regular phone number, is completely portable. Most
commonly referred to as a virtual number, you can take it with you anywhere you go.
Even if you change your office address to another state, you phone number can go with you.
Heck, you can even take your whole business with you wherever you travel.
Features :
Unlike regular phone service which usually charges more for extra features, VOIP comes with
a host of advanced communication features. For example, call forwarding, call waiting,
voicemail, caller ID and three-way calling are some of the many services included with VOIP
telephone service at no extra charge. You can also send data such as pictures and documents
at the same time you are talking on the phone.
VoIP phones can integrate with other services available over the Internet, including video
conversation, message or data file exchange in parallel with the conversation, audio
conferencing, managing address books and passing information about whether others (e.g.
friends or colleagues) are available online to interested parties.
Flexibility :
When you choose a VoIP phone service provider, you will be sent a converter to allow a
regular phone to use the VoIP phone service. Your phone number is programmed into the
converter. This means that you can take your phone converter and phone number and use
them wherever you travel in the world, just as long as you have access to a high-speed
Internet connection. Because your telephone number is based in your converter (and not your
home/office), you have the option of choosing any area code for your phone number. Some
carriers will allow you to have more than 1 phone number in different area codes for a small
additional fee (called a virtual phone number).
video-conferencing :
VoIP enables advanced bandwidth capabilities and improved video-conferencing and at a
reasonable price.
Disadvantages of VoIP:
If VOIP is starting to sound really good to you, make sure you understand the following
downsides as well.
No service during a power outage :
During a blackout a regular phone is kept in service by the current supplied through the phone
line. This is not possible with IP phones, so when the power goes out, there is no VOIP phone
service. In order to use VoIP during a power outage, an uninterruptible power supply or a
generator must be installed on the premises. It should be noted that many early adopters of
VoIP are also users of other phone equipment such as PBX and cordless phone bases that
also rely on power not provided by the telephone company.
Emergency calls :
Another major concern with VOIP involves emergency 911 calls. Traditional phone equipment
can trace your location. Emergency calls are diverted to the nearest call center where the
operator can see your location in case you can't talk. However, because a voice-over-IP call
is essentially a transfer of data between two IP addresses, not physical addresses, with VOIP
there is currently no way to determine where your VOIP phone call is originating from.
Although many companies are making an effort to provide for emergency calls in their service,
this issue remains an important deterrent against VoIP.
Reliability :
Because VOIP relies on an Internet connection, your VOIP service will be affected by the
quality and reliability of your broadband Internet service and sometimes by the limitations of
your PC. Poor Internet connections and congestion can result in garbled or distorted voice
quality. If you are using your computer at the same time as making a computer VOIP call,
you may find that voice quality deteriorates dramatically.
This is more noticeable in highly congested networks and/or where there are long distances
and/or internetworking between end points.
VoIP Voice Quality :
VoIP has a bit to improve on Voice Quality, but not in all cases. VoIP QoS(Quality of service)
depends on so many factors: your broadband connection, your hardware, the service provided
by your provider, the destination of your call etc. More and more people are enjoying high
quality of phone calls using VoIP, but still many users complain of hearing Martian, having to
wait a lot before hearing an answer etc.
Security :
This one is the last in this list, but it is not the least! Security is a main concern with VoIP, as
it is with other Internet technologies. The most prominent security issues over VoIP are
identity and service theft, viruses and malware, denial of service, spamming, call tampering
and phishing attacks.
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