Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Bitrate shopping experience:
1. Compare - without doubt the biggest advantage that the Bitrate offers shoppers today is the ability to compare thousands of Bitrate at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Bitrate? Wrong! If the Bitrate is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Bitrate then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Bitrate? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Bitrate and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Bitrate wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Bitrate then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Bitrate site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Bitrate, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Bitrate, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
In
telecommunications and computing,
bitrate (sometimes written
bit rate,
data rate or as a variable
R or
fb) is the number of
bits that are conveyed or processed per unit of time. Bit rate is synonymous to
data rate and digital bandwidth.
The bit rate is quantified using the 'bit per second' (
bit/s or
bps) unit, often in conjunction with a SI prefix such as kilo- (kbit/s or kbps),
mega- (Mbit/s or Mbps),
giga- (Gbit/s or Gbps) or
tera- (Tbit/s or Tbps).
In digital communication systems, the
gross bitrate,
raw bitrate, data signaling rate or line rate is the total number of physically transferred bits per second over a communication link, including useful data as well as protocol overhead.
The
net bitrate,
useful bit rate or
data transfer rate of a digital communication link is the capacity excluding the physical layer protocol overhead, typically redundant forward error correction and other
channel coding. The relationship between the gross bit rate and net bit rate is affected by the forward error correction
code rate according to the following.
Gross bit rate ·
code rate ≥ Net bit rate
The
Connection speed or data transfer rate of a network access technology or communication device typically refers to the physical layer net bit rate in accordance with the above definition. For example, the bit rate of 100 Mbit/s of an Ethernet 100Base-TX physical layer, the downlink bit rate of 56000 bit/s of a V.92 modem and the bit rate of between 6 and 54 Mbit/s of a 802.11a wireless network, all refer to the net bit rate.
The channel capacity is a theoretical upper bound for the maximum net bitrate, exclusive of forward error correction coding, that is possible without bit errors for a certain physical point-to-point
communication channel.
Channel capacity ≥ Net bit rate
The term
throughput or
digital bandwidth consumption denotes the achieved bit rate in a computer network over a logical or physical communication link or through a network node, typically measured at a reference point below the
network layer and above the physical layer.
Goodput refers to the achieved net bit rate that is delivered to the application layer, exclusive of all protocol overhead, data packets retransmissions, etc. For example, in the case of file transfer, the goodput corresponds to the achieved
file transfer rate. The file transfer rate in bit/s can be calculated as the file size (in byte), divided by the file transfer time (in seconds), and multiplied by eight.
Net bit rate ≥ Maximum throughput ≥ Throughput ≥ Goodput
In digital
multimedia,
bit rate often refers to the number of bits used per unit of time to represent a continuous medium such as sound recording or video after
source coding (data compression). The size of a multimedia file in
byte is the product of the bit rate (in bit/s) and the length of the recording (in seconds), times eight. In case of streaming multimedia, this bit rate measure is the
goodput that is required to avoid interrupts.
Required goodput ≥ Goodput
Usage notes
The formal abbreviation for "bit per second" is "bit/s" (not "bits/s"). In less formal contexts the abbreviations "b/s" or "bps" are often used, though this risks confusion with "
bytes per second" ("B/s", "Bps"). Even less formally, it is common to drop the "per second", and simply refer to "a 128 kilobit audio stream" or "a 100 megabit network".
Gross bit rate is sometimes used interchangeably with "baud rate", which is correct
only when each modulation transition of a data transmission (telecommunications) system carries exactly one bit of data (something not true for modern
modem modulation systems, for example).
While often referred to as "speed", bitrate does not measure
distance/time but
quantity/time, and should be distinguished from the "
velocity of propagation" (which depends on the transmission medium and has the usual physical meaning).
Prefixes
For large bitrates,
SI prefixes are used:{] (one kilobit or one thousand bits per second)] (one
megabit or one
million bits per second)] (one gigabit or one 1000000000 (number) bits per second)|}
When describing bitrates,
binary prefixes have almost never been used and
SI prefixes are almost always used with the standard, decimal meanings, not the old computer-oriented binary meanings. Binary usage may occasionally be seen when the unit is the byte/s, and is not typical for telecommunication links. Sometimes it is necessary to seek clarification of the units used in a particular context.
Progress trends
Looking at the development of transmission speeds,
Moores Law may be applied not only to transistor densities, but as well as to transmission speeds: bitrates doubled about every 18 months.
Improvement in applied bitrates :{|class="wikitable" style="margin: 1em auto 1em auto"!year || WAN || LAN || WLAN|-| 2005 || 16 M || 1 G || 100 M|-| 2000 || 2 M || 100 M || 10 M|-| 1995 || 128 k || 10 M || 1 M|-| 1990 || 19 k || 1 M |||-| 1985 || 1 k || |||-|-| 1970 || || ? |||}
Proposed standards and first devices :{| class="wikitable" style="margin: 1em auto 1em auto"|-! WAN! LAN! WLAN|-|
- 1972: Acoustic coupler 300 baud
- 1985: 1200 baud
- 1990: increasing Modem speed: 2400 / 4800 / 9600 / 19200 bit/s
- 1995: v.34 modems with 28.8 kbit/s, v.90 modems with 56 kbit/s
- 1996: ISDN with two 64 kbit/s channels
- 1998: Asymmetric Digital Subscriber Line from 128 kbit/s to 8 Mbit/s, ADSL2 up to 12 Mbit/s, ADSL2+ up to 24 Mbit/s
|
- 1972: IEEE 802.3 Ethernet 2.94 Mbit/s
- 1985: 10b2 10 Mbit/s coax thinwire
- 1990: 10BASE-T 10 Mbit/s
- 1995: 100bT 100 Mbit/s
- 1999: 1000bT (Gigabit) 1 Gbit/s
- 2003: 10GBASE 10 Gbit/s
|
|}
Bitrates in multimedia
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 data compression 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 — Mediumwave (AM broadcasting) quality
- 96 kbit/s — FM broadcasting quality
- 128–160 kbit/s — Standard Bitrate quality; difference can sometimes be obvious (e.g. bass quality)
- 192 kbit/s — DAB (Digital Audio Broadcasting) quality. Quickly becoming the new 'standard' bitrate for MP3 music; difference can be heard by few people.
- 224–320 kbit/s — Near CD Quality. Sound is near indistinguishable from most CDs.
Other audio
- 800 bit/s — minimum necessary for recognizable speech (using special-purpose FS-1015 speech encoding)
- 8 kbit/s — telephone quality (using speech codecs)
- 500 kbit/s–1 Mbit/s — Lossless data compression as used in formats such as FLAC, WavPack or Monkey's Audio
- 1411 kbit/s — PCM sound format of Compact Disc Digital Audio
Video (MPEG2)
- 16 kbit/s — videophone quality (minimum necessary for a consumer-acceptable "talking head" picture)
- 128 – 384 kbit/s — business-oriented videoconferencing system quality
- 1 Mbit/s — VHS quality
- 5 Mbit/s — DVD quality
- 15 Mbit/s — High-definition television quality
- 36 Mbit/s — HD DVD quality
- 54 Mbit/s — Blu-ray Disc quality
Notes
For technical reasons (hardware/software protocols, overheads, encoding schemes, etc.) the
actual bitrates used by some of the compared-to devices may be significantly higher than what is listed above. For example:
- Telephone circuits using Mu-law algorithm or A-law algorithm companding (pulse code modulation) — 64 kbit/s
- CDs using CDDA — 1.4 Mbit/s
References
Maximum PC - Do Higher MP3 Bit Rates Pay Off?
See also
External links
Bandwidth conversion
Allow easy conversion from kbit/s to MB/h to GB/day to TB/month to ...
Bandwidth calculator online
- VoIP Bandwidth Calculator - Given a codec type and sample period calculate the actual IP and Ethernet bandwidth.
- VoIP Bandwidth Calculation White Paper - Companion paper to the above calculator explaining how Voice becomes Voice over IP.
- StreamingMarketplace.com( Calculate streaming bandwidth and storage)
Bitrates of DVB-S TV and radio channels
- Linowsat - daily updated audio and video bitrates of European satellites.
In telecommunications and computing,
bitrate (sometimes written
bit rate,
data rate or as a variable
R or
fb) is the number of
bits that are conveyed or processed per unit of time. Bit rate is synonymous to
data rate and
digital bandwidth.
The bit rate is quantified using the 'bit per second' (
bit/s or
bps) unit, often in conjunction with a SI prefix such as
kilo- (kbit/s or kbps), mega- (Mbit/s or Mbps),
giga- (Gbit/s or Gbps) or
tera- (Tbit/s or Tbps).
In digital communication systems, the
gross bitrate,
raw bitrate, data signaling rate or line rate is the total number of physically transferred bits per second over a communication link, including useful data as well as protocol overhead.
The
net bitrate,
useful bit rate or data transfer rate of a digital communication link is the capacity excluding the
physical layer protocol overhead, typically redundant forward error correction and other channel coding. The relationship between the gross bit rate and net bit rate is affected by the forward error correction code rate according to the following.
Gross bit rate · code rate ≥ Net bit rate
The
Connection speed or data transfer rate of a network access technology or communication device typically refers to the physical layer net bit rate in accordance with the above definition. For example, the bit rate of 100 Mbit/s of an Ethernet 100Base-TX physical layer, the downlink bit rate of 56000 bit/s of a V.92 modem and the bit rate of between 6 and 54 Mbit/s of a 802.11a wireless network, all refer to the net bit rate.
The channel capacity is a theoretical upper bound for the maximum net bitrate, exclusive of forward error correction coding, that is possible without bit errors for a certain physical point-to-point communication channel.
Channel capacity ≥ Net bit rate
The term throughput or
digital bandwidth consumption denotes the achieved bit rate in a computer network over a logical or physical communication link or through a network node, typically measured at a reference point below the network layer and above the
physical layer.
Goodput refers to the achieved net bit rate that is delivered to the application layer, exclusive of all protocol overhead, data packets retransmissions, etc. For example, in the case of file transfer, the goodput corresponds to the achieved
file transfer rate. The file transfer rate in bit/s can be calculated as the file size (in byte), divided by the file transfer time (in seconds), and multiplied by eight.
Net bit rate ≥ Maximum throughput ≥ Throughput ≥ Goodput
In digital
multimedia,
bit rate often refers to the number of bits used per unit of time to represent a continuous medium such as sound recording or
video after
source coding (data compression). The size of a multimedia file in byte is the product of the bit rate (in bit/s) and the length of the recording (in seconds), times eight. In case of streaming multimedia, this bit rate measure is the
goodput that is required to avoid interrupts.
Required goodput ≥ Goodput
Usage notes
The formal abbreviation for "bit per second" is "bit/s" (not "bits/s"). In less formal contexts the abbreviations "b/s" or "bps" are often used, though this risks confusion with "
bytes per second" ("B/s", "Bps"). Even less formally, it is common to drop the "per second", and simply refer to "a 128 kilobit audio stream" or "a 100 megabit network".
Gross bit rate is sometimes used interchangeably with "
baud rate", which is correct
only when each modulation transition of a data transmission (telecommunications) system carries exactly one bit of data (something not true for modern modem modulation systems, for example).
While often referred to as "speed", bitrate does not measure
distance/time but
quantity/time, and should be distinguished from the "
velocity of propagation" (which depends on the transmission medium and has the usual physical meaning).
Prefixes
For large bitrates, SI prefixes are used:{] (one kilobit or one thousand bits per second)] (one megabit or one
million bits per second)] (one
gigabit or one
1000000000 (number) bits per second)|}
When describing bitrates,
binary prefixes have almost never been used and SI prefixes are almost always used with the standard, decimal meanings, not the old computer-oriented binary meanings. Binary usage may occasionally be seen when the unit is the byte/s, and is not typical for telecommunication links. Sometimes it is necessary to seek clarification of the units used in a particular context.
Progress trends
Looking at the development of transmission speeds,
Moores Law may be applied not only to transistor densities, but as well as to transmission speeds: bitrates doubled about every 18 months.
Improvement in applied bitrates :{|class="wikitable" style="margin: 1em auto 1em auto"!year || WAN || LAN || WLAN|-| 2005 || 16 M || 1 G || 100 M|-| 2000 || 2 M || 100 M || 10 M|-| 1995 || 128 k || 10 M || 1 M|-| 1990 || 19 k || 1 M |||-| 1985 || 1 k || |||-|-| 1970 || || ? |||}
Proposed standards and first devices :{| class="wikitable" style="margin: 1em auto 1em auto"|-! WAN! LAN! WLAN|-|
- 1972: Acoustic coupler 300 baud
- 1985: 1200 baud
- 1990: increasing Modem speed: 2400 / 4800 / 9600 / 19200 bit/s
- 1995: v.34 modems with 28.8 kbit/s, v.90 modems with 56 kbit/s
- 1996: ISDN with two 64 kbit/s channels
- 1998: Asymmetric Digital Subscriber Line from 128 kbit/s to 8 Mbit/s, ADSL2 up to 12 Mbit/s, ADSL2+ up to 24 Mbit/s
|
- 1972: IEEE 802.3 Ethernet 2.94 Mbit/s
- 1985: 10b2 10 Mbit/s coax thinwire
- 1990: 10BASE-T 10 Mbit/s
- 1995: 100bT 100 Mbit/s
- 1999: 1000bT (Gigabit) 1 Gbit/s
- 2003: 10GBASE 10 Gbit/s
|
|}
Bitrates in multimedia
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 data compression 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 — Mediumwave (AM broadcasting) quality
- 96 kbit/s — FM broadcasting quality
- 128–160 kbit/s — Standard Bitrate quality; difference can sometimes be obvious (e.g. bass quality)
- 192 kbit/s — DAB (Digital Audio Broadcasting) quality. Quickly becoming the new 'standard' bitrate for MP3 music; difference can be heard by few people.
- 224–320 kbit/s — Near CD Quality. Sound is near indistinguishable from most CDs.
Other audio
Video (MPEG2)
Notes
For technical reasons (hardware/software protocols, overheads, encoding schemes, etc.) the
actual bitrates used by some of the compared-to devices may be significantly higher than what is listed above. For example:
- Telephone circuits using Mu-law algorithm or A-law algorithm companding (pulse code modulation) — 64 kbit/s
- CDs using CDDA — 1.4 Mbit/s
References
Maximum PC - Do Higher MP3 Bit Rates Pay Off?
See also
External links
Bandwidth conversion
Allow easy conversion from kbit/s to MB/h to GB/day to TB/month to ...
Bandwidth calculator online
- VoIP Bandwidth Calculator - Given a codec type and sample period calculate the actual IP and Ethernet bandwidth.
- VoIP Bandwidth Calculation White Paper - Companion paper to the above calculator explaining how Voice becomes Voice over IP.
- StreamingMarketplace.com( Calculate streaming bandwidth and storage)
Bitrates of DVB-S TV and radio channels
- Linowsat - daily updated audio and video bitrates of European satellites.
