Voice over IP (VoIP, or voice over Internet Protocol) commonly refers to the communication protocols, technologies, methodologies, and transmission techniques involved in the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet.
Early providers of voice over IP services offered business models (and technical solutions) that mirrored the architecture of the legacy telephone network. Second generation providers, such as Skype have built closed networks for private user bases, offering the benefit of free calls and convenience, while denying their users the ability to call out to other networks. This has severely limited the ability of users to mix-and-match third-party hardware and software. Third generation providers, such as Google Talk have adopted the concept of Federated VoIP – which is a complete departure from the architecture of the legacy networks. These solutions typically allow arbitrary and dynamic interconnection between any two domains on the Internet whenever a user wishes to place a call.
VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codecs which encode speech allowing transmission over an IP network as digital audio via an audio stream. The choice of codec varies between different implementations of VoIP depending on application requirements and network bandwidth; some implementations rely on narrowband and compressed speech, while others support high fidelity stereo codecs. Some popular codecs include u-law and a-law versions of G.711, G.722 which is a high-fidelity codec marketed as HD Voice by Polycom, a popular open source voice codec known as iLBC, a codec that only uses 8 kbit/s each way called G.729, and many others.
VoIP is available on many smartphones and Internet devices so that users of portable devices that are not phones, may place calls or send SMS text messages over 3G or Wi-Fi.
Thursday, 15 November 2012
The Effects Of 4G
The Effects Of 4G:
The introduction of 4G will allow everyone to browse the internet of their mobile phones much faster and will diminish "Buffering." However, this was said about 3G when it came out and within quite a short period of time, the amount of time it took for the majority of the population to get it, it became very slow, hence the need for the move to 4G. So basically, 4G will be very good, but we will soon need "5G" or something else that will allow fast browsing.
4G has and will benefit companies and businesses also, because of the huge usage of emails etc that help businesses in contacting their partners and othe businesses.
The introduction of 4G will allow everyone to browse the internet of their mobile phones much faster and will diminish "Buffering." However, this was said about 3G when it came out and within quite a short period of time, the amount of time it took for the majority of the population to get it, it became very slow, hence the need for the move to 4G. So basically, 4G will be very good, but we will soon need "5G" or something else that will allow fast browsing.
4G has and will benefit companies and businesses also, because of the huge usage of emails etc that help businesses in contacting their partners and othe businesses.
Friday, 9 November 2012
Different Types Of Computors
Desktop Computors:
These re probably the type of computer you are most familiar with. They come with a monitor (now usually a TFT screen), keyboard, mouse, CD-RW and a DVD-RW or at least a DVD-ROM.
These re probably the type of computer you are most familiar with. They come with a monitor (now usually a TFT screen), keyboard, mouse, CD-RW and a DVD-RW or at least a DVD-ROM.
Laptop Computors:
These are also very common. They usually have the same processors as desktops and similar sized main memory and
hard disk drive, although you will pay more for a laptop as a desktop with the
same specification. Laptops have the advantage that they can carried about
easily and run from a battery. Often they have built in wireless technology
allowing them to connected to network without having to use cables. Laptops do
not come with a mouse due to the fact that they are often used where there in
not a table to use a mouse on. Instead they have a touchpad built into them. You
would also expect a laptop to have a CD-RW and DVD-ROM as standard.
Palmtop Computers (sometimes called PDAs (Personal
Digital Assistants)):
These have a small touch senstive screen and come with a stylus
allowing the user to select things off screen. Data entry is usually done using
handwriting recognition although some PDAs do have a small keyboard. They can be
used to do tasks similar to ones done by desktop and laptops but more often they
are used for note taking, calendars, address books and a means of sending and
recieving email. A palmtop works together with a desktop or laptop so data can
be transferred between computers. This is done using a cable or using
Bluetooth wireless technology.
Mainframe Computers:
These are very large powerful
computer systems that are usually at the heart of a business. The mainframe
computer will have a very powerful processor, large amounts of main memory and a
huge backing storage capacity. They are accessed through one or more
terminals. Terminals consist of a screen, keyboard, mouse but no
processor as all the processing is done by the mainframe.
Wednesday, 7 November 2012
Task 1.11
Teacher: Laptop, can work from home if
needed and can easily move from classroom to
classroom.
News
Reporter: A news reporter would use a Notebook as it has very high mobility, and
its main use is for writing documents.
Website
Designer: Desktop, working in a stationary environment, working with
something purely on the computer.
Doctor: Desktop, high performance and doesn't need to be mobile.
Traffic
Warden: A PDA would be the easiest choice for a traffic warden because it
doesn’t take long to start up and is very mobile.
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