Telecommunications and New technologies.

the ground wave used for radio communications signal propagation on the long, and medium wave bands for local radio communications Ground wave propagation is particularly important on the LF and MF portion of the radio spectrum. Ground wave radio propagation is used to provide relatively local radio communications coverage, especially by radio broadcast stations that require to cover a particular locality. Ground wave radio signal propagation is ideal for relatively short distance propagation on these frequencies during the daytime. Sky-wave ionospheric propagation is not possible during the day because of the attenuation of the signals on these frequencies caused by the D region in the ionosphere. In view of this, radio communications stations need to rely on the ground-wave propagation to achieve their coverage. A ground wave radio signal is made up from a number of constituents. If the antennas are in the line of sight then there will be a direct wave as well a...

[WiMax - 802.16d/e] WiMAX is a term coined to describe standard, interoperable implementations of IEEE 802.16 wireless networks, in a rather similar way to Wi-Fi being interoperable implementations of the IEEE 802.11 Wireless LAN standard. However, WiMAX is very different from Wi-Fi in the way it works. In Wi-Fi, the media access controller ("MAC") uses contention access - all subscriber stations that wish to pass data through a wireless access point ("AP") are competing for the AP's attention on a random interrupt basis. This can cause distant nodes from the AP to be repeatedly interrupted by closer nodes, greatly reducing their throughput. This makes services such as Voice over IP (VoIP) or IPTV, which depend on a predetermined type of "quality of service" (QoS), difficult to maintain for large numbers of users. In contrast, the 802.16 MAC uses a scheduling algorithm, where the subscriber station only has to compete once (for initial en...

[MSAN] A Multi Service Access Node (MSAN) is a device typically installed in a telephone exchange (although sometimes in a roadside serving area interface cabinet) which connects customers' telephone lines to the core network, to provide telephony, ISDN, and broadband such as DSL all from a single platform. Prior to the deployment of MSANs, telecom providers typically had a multitude of separate equipment including DSLAMs to provide the various types of services to customers. Integrating all services on a single node, which typically backhauls all data streams over IP or Asynchronous Transfer Mode can be more cost effective and may more quickly provide new services to customers. Typical outdoor MSAN cabinet consists of NarrowBand (POTS), BroadBand (xDSL) services, batteries with rectifiers, optical transmission unit and copper distribution frame. [DSLAM] A Digital Subscriber Line Access Multiplexer (DSLAM) allows telephone lines to make faster connections to t...

[IPTV] IPTV (Internet Protocol Television) is a system where a digital television service is delivered using Internet Protocol over a network infrastructure, which may include delivery by a broadband connection. A general definition of IPTV is television content that, instead of being delivered through traditional broadcast and cable formats, is received by the viewer through the technologies used for computer networks. For residential users, IPTV is often provided in conjunction with Video on Demand and may be bundled with Internet services such as Web access and VoIP. The commercial bundling of IPTV, VoIP and Internet access is referred to as "Triple Play" service (adding mobility is called "Quadruple Play"). IPTV is typically supplied by a service provider using a closed network infrastructure. This closed network approach is in competition with the delivery of TV content over the public Internet, called Internet Television. In businesses, I...

Optical communication systems date back to the 1790s, to the optical semaphore telegraph invented by French inventor Claude Chappe. In 1880, Alexander Graham Bell patented an optical telephone system, which he called the Photophone. However, his earlier invention, the telephone, was more practical and took tangible shape. The Photophone remained an experimental invention and never materialized. During the 1920s, John Logie Baird in England and Clarence W. Hansell in the United States patented the idea of using arrays of hollow pipes or transparent rods to transmit images for television or facsimile systems. In 1954, Dutch scientist Abraham Van Heel and British scientist Harold H. Hopkins separately wrote papers on imaging bundles. Hopkins reported on imaging bundles of unclad fibers, whereas Van Heel reported on simple bundles of clad fibers. Van Heel covered a bare fiber with a transparent cladding of a lower refractive index. This protected the fiber reflection surface from ou...

4G is short for Fourth (4th) Generation Technology . 4G Technology is basically the extension in the 3G technology with more bandwidth and services offers in the 3G. But at this time nobody exactly knows the true 4G definition . Some people say that 4G technology is the future technologies that are mostly in their maturity period. The expectation for the 4G technology is basically the high quality audio/video streaming over end to end Internet Protocol. If the Internet Protocol (IP) multimedia sub-system movement achieves what it going to do, nothing of this possibly will matter. WiMAX or mobile structural design will become progressively more translucent, and therefore the acceptance of several architectures by a particular network operator ever more common. Many Technologies appear in many different flavours and have many diverse tags attached to them, but that does not really indicate that they are moving in dissimilar tracks. The technologies that fa...

3 New Windows 4G Phones from AT&T By 4G Phones, September 13 2011 Samsung Focus - AT&T Windows Phone AT&T is going for Windows 4G phones is a big way this Fall by introducing three new Windows 4G capable phones and upgrading its existing range of devices. The upcoming AT&T Windows phones are: The Samsung Focus S which will come with 4.3 inch screen, 1.4 GHz processor and 8-megapixel rear camera. This is a follow up to already available Samsung Focus, which comes with a 4 inch screen, 1GHz processor and 5-megapixel camera. The HTC TITAN will ship with a 4.7 inch screen (not a typo) and will be the largest screen in the AT&T range of phones and will have a 1.5 GHz processor and 8-megapixel camera. Little else is confirmed about the HTC Titan at this point. If you’re looking for a large screen phone for AT&T and can’t wait for the Titan take a look at the 4.5 inch Samsung Infuse or the 4.3 inch Thrill 4G. The Samsung Focus Flash d...

Samsung Galaxy Tab 7.7 Tablet with support for GSM voice communication, SMS, and MMS. The Samsung Galaxy Tab 7.7 is the first tablet to feature a 7.7-inch Super AMOLED display. Under the hood, there is a 1.4GHz processor, making the TouchWiz skinned Android Honeycomb 3.2 tick. The tablet sports a 3-megapixel camera on the back and a 2-megapixel front shooter and has a 5100mAh battery, which delivers up to 10 hours of non-stop video playback. Here it is, official as official gets: Samsung just announced the Galaxy Tab 7.7. As the name suggests, it has a 7.7-inch (1280 x 800) display -- specifically, a Super AMOLED Plus panel. Like so many other 7-inchers hitting the market, it runs Android 3.2 and yes, that's a skinned flavor of Honeycomb, with Samsung's tablet-optimized TouchWiz UX layered on top. Inside, it runs the same Samsung-made dual-core 1.4GHz processor found in the new Galaxy Note , along with an HSPA+ radio promising theoretical download s...

IPv6 or Internet Protocol Version 6 is the next generation protocol for the Internet. It's designed to provide several advantages over current Internet Protocol Version 4 (or IPv4). Both IPv6 and IPv4 define network layer protocol i.e., how data is sent from one computer to another computer over packet-switched networks such as the Internet.   Specifically, IPv6 contains addressing and control information to route packets for the next generation Internet.We believe that the expansion of the Internet is important and upgrades are sometimes warranted. Gathering information concering every aspects of IPv6 we would hope to provide knowledge about this technology so everyone can benefit. It is therefore also called the Next Generation Internet Protocol or   IPng   .   IPv6 is documented in several RFCs (or request for comments) starting from RFC 2460. Although IPv6 is the successor of ...

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