Category Archives: Tips and Tricks

4G

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4G refers to the fourth generation of cellular wireless standards. It is a successor to 3G and 2G standards. The nomenclature of the generations generally refers to a change in the fundamental nature of the service. The first was the move from analogue (1G) to digital (2G) transmission. This was followed by multi-media support, spread spectrum transmission and at least 200 kbit/s (3G) and now 4G, which refers to all IP packet-switched networks, mobile ultra-broadband (gigabit speed) access and multi-carrier transmission.

A 4G system is expected to provide a comprehensive and secure all-IP based solution where facilities such as IP telephony, ultra-broadband Internet access, gaming services and streamed multimedia may be provided to users.

The remainder of this article uses 4G to refer to IMT Advanced (International Mobile Telecommunications Advanced), as defined by ITU-R.

An IMT advanced cellular system must have target peak data rates of up to approximately 100 Mbit/s for high mobility such as mobile access and up to approximately 1 Gbit/s for low mobility such as nomadic/local wireless access, according to the ITU requirements. Scalable bandwidths up to at least 40 MHz should be provided.[1][2]

In all these suggestions for 4G, the CDMA spread spectrum radio technology used in 3G systems and IS-95 is abandoned and replaced by frequency-domain equalization schemes, for example multi-carrier transmission such as OFDMA. This is combined with MIMO (i.e. multiple antennas(Multiple In Multiple Out)), dynamic channel allocation and channel-dependent scheduling.

Multimedia bit rates

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In digital multimedia, bitrate represents the amount of information, or detail, that is stored per unit of time of a recording. The bitrate depends on several factors:

* The original material may be sampled at different frequencies
* The samples may use different numbers of bits
* The data may be encoded by different schemes
* The information may be digitally compressed by different algorithms or to different degrees

Generally, choices are made about the above factors in order to achieve the desired trade-off between minimizing the bitrate and maximizing the quality of the material when it is played.

If lossy data compression is used on audio or visual data, differences from the original signal will be introduced; if the compression is substantial, or lossy data is decompressed and recompressed, this may become noticeable in the form of compression artifacts. Whether these affect the perceived quality, and if so how much, depends on the compression scheme, encoder power, the characteristics of the input data, the listener’s perceptions, the listener’s familiarity with artifacts, and the listening or viewing environment.

The bitrates in this section are approximately the minimum that the average listener in a typical listening or viewing environment, when using the best available compression, would perceive as not significantly worse than the reference standard:

Audio (MP3)

* 32 kbit/s – MW (AM) quality
* 96 kbit/s – FM quality
* 128–160 kbit/s – Standard Bitrate quality; difference can sometimes be obvious (e.g. lack of low frequency quality and high frequency “swashy” effects)[citation needed]
* 192 kbit/s – DAB (Digital Audio Broadcasting) quality.
* 224–320 kbit/s – VBR to highest MP3 quality

Other audio

* 800 bit/s – minimum necessary for recognizable speech (using special-purpose FS-1015 speech codecs)
* 8 kbit/s – telephone quality (using speech codecs)
* 32-500 kbit/s — lossy audio as used in Ogg Vorbis
* 500 kbit/s–1,411kbit/s – lossless audio as used in formats such as Free Lossless Audio Codec, WavPack or Monkey’s Audio
* 1,411.2 kbit/s – PCM sound format of Compact Disc Digital Audio

Video

* 16 kbit/s – videophone quality (minimum necessary for a consumer-acceptable “talking head” picture using various video compression schemes)
* 128 – 384 kbit/s – business-oriented videoconferencing quality using video compression
* 1.25 Mbit/s – VCD quality (with bit-rate reduction from MPEG-1 video compression)[citation needed]
* 1374 kbit/s – VCD (Video CD) – audio and video streams multiplexed in an MPEG-PS
* 3.5 Mbit/s typ – Standard-definition television quality (with bit-rate reduction from MPEG-2 compression)
* 5 Mbit/s typ – DVD quality (with bit-rate reduction from MPEG-2 compression)
* 8 to 15 Mbit/s typ – HDTV quality (with bit-rate reduction from MPEG-4 AVC compression)
* 29.4 Mbit/s max – HD DVD
* 40 Mbit/s max – Blu-ray Disc

SPDY

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SPDY, pronounced “Speedy”, is an application-level protocol for transporting web content. It is a proposed replacement for the HTTP protocol and created by Google.

The goal of SPDY is to reduce web page load time.This is achieved by prioritizing and multiplexing the transfer of several files so that only one connection per client is required. All transmissions are SSL encrypted and gzip compressed by design (in contrast to HTTP, the headers are compressed too). Moreover, servers may hint or even push content instead of awaiting individual requests for each resource of a web page.

Microsoft security essentials

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Microsoft Security Essentials (MSE) (previously codenamed Morro) is a free antivirus software created by Microsoft that provides protection against viruses, spyware, rootkits, and trojans for Windows XP (x86), Windows Vista, and Windows 7 (both x86 and x64), free of charge. MSE replaces Windows Live OneCare, a commercial subscription-based antivirus service and the free Windows Defender, which only protected users from adware and spyware. It is geared for consumer use, unlike Microsoft’s upcoming enterprise-oriented product Microsoft Forefront.

Symantec and McAfee, two competing antivirus vendors, responded by claiming that MSE is not as good as their own software. AVG Technologies viewed MSE positively, stating it reinforced the company’s ideal of free antivirus software. Reviews were mostly positive, citing its organized interface, low resource usage, and its status as freeware.

Reveal asterisk using javascript

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Reveal Asterisk (*****) using javascript !

Follow the steps given below-

1. Open the Login Page of any website. (eg. http://mail.google.com)

2. Type your ‘Username’ and ‘Password’.

3. Copy and paste the JavaScript code given below into your browser’s address bar and press ‘Enter’.

javascript: alert(document.getElementById(‘Passwd’).

value);

4. As soon as you press ‘Enter’, A window pops up showing Password typed by you..!