Transcript Document

• Statistical Multiplexing
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4G Key features
Frequency-domain statistical
multiplexing, for example (OFDMA) or
(single-carrier FDMA) (SC-FDMA, a.k.a.
linearly precoded OFDMA, LP-OFDMA)
in the uplink: Variable bit rate by
assigning different sub-channels to
different users based on the channel
conditions
1
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Passive optical network - Upstream bandwidth allocation
Through dynamic bandwidth
allocation (DBA), a PON can be
oversubscribed for upstream traffic,
according to the traffic engineering
concepts of statistical multiplexing
1
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Passive optical network - WDM-PON
1
The multiple wavelengths of a WDMPON can be used to separate Optical
Network Units (ONUs) into several
virtual PONs co-existing on the same
physical infrastructure. Alternatively
the wavelengths can be used
collectively through statistical
multiplexing to provide efficient
wavelength utilization and lower
delays experienced by the ONUs.
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Multiplexing - Types of multiplexing
1
Multiple variable bit rate digital bit streams
may be transferred efficiently over a single
fixed bandwidth channel by means of
statistical multiplexing, for example packet
mode communication. Packet mode
communication is an asynchronous mode
time-domain multiplexing which resembles
time-division multiplexing.
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Multiplexing - Code-division multiplexing
Advantages over conventional
techniques are that variable
bandwidth is possible (just as in
statistical multiplexing), that the wide
bandwidth allows poor signal-to-noise
ratio according to Shannon-Hartley
theorem, and that multi-path
propagation in wireless
communication can be combated by
rake receivers.
1
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Multiplexing - Relation to multiple access
1
A multiplexing technique may be further
extended into a multiple access method or
channel access method, for example TDM
into Time-division multiple access (TDMA)
and statistical multiplexing into carrier
sense multiple access (CSMA). A multiple
access method makes it possible for
several transmitters connected to the
same physical medium to share its
capacity.
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Multiplexing - Relation to multiple access
1
The Transport layer in the OSI model as
well as TCP/IP model provides
statistical multiplexing of several
application layer data flows to/from the
same computer.
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Multiplexing - Digital broadcasting
In digital television and digital radio
systems, several variable bit-rate data
streams are multiplexed together to a fixed
bitrate transport stream by means of
statistical multiplexing. This makes it
possible to transfer several video and
audio channels simultaneously over the
same frequency channel, together with
various services.
1
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General Packet Radio Service - Multiple access schemes
This is combined with time domain
statistical multiplexing; i.e., packet mode
communication, which makes it possible
for several users to share the same
frequency channel
1
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Evolution-Data Optimized - TIA-856 Rev. B
Reduced latency by using statistical
multiplexing across channels—enhances
the experience for latency sensitive
services such as gaming, video telephony,
remote console sessions and web
browsing.
1
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Packet switching - Overview
1
Packet switching features delivery of variable
bitrate data streams (sequences of packets)
over a shared network which allocates
transmission resources as needed using
statistical multiplexing or dynamic bandwidth
allocation techniques. When traversing
network adapters, switches, routers, and
other network nodes, packets are buffered
and queued, resulting in variable delay and
throughput depending on the network's
capacity and the traffic load on the network.
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Round-robin scheduling - Network packet scheduling
1
In best-effort packet switching and other
statistical multiplexing, round-robin
scheduling can be used as an alternative
to first-come first-served queuing.
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Statistical time division multiplexing
1
When performed correctly, statistical
multiplexing can provide a link
utilization improvement, called the
statistical multiplexing gain.
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Statistical time division multiplexing
1
Statistical multiplexing is facilitated through
packet mode or packet-oriented
communication, which among others is
utilized in packet switched computer
networks. Each stream is divided into packets
that normally are delivered asynchronously in
a first-come first-served fashion. In alternative
fashion, the packets may be delivered
according to some scheduling discipline for
fair queuing or differentiated and/or
guaranteed quality of service.
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Statistical time division multiplexing
1
Statistical multiplexing of an analog
channel, for example a wireless
channel, is also facilitated through the
following schemes:
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Statistical time division multiplexing
1
Statistical multiplexing normally implies
"on-demand" service rather than one that
preallocates resources for each data
stream. Statistical multiplexing schemes
do not control user data transmissions.
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Statistical time division multiplexing - Comparison with static TDM
Time domain statistical multiplexing
(packet mode communication) is similar to
time-division multiplexing (TDM), except
that, rather than assigning a data stream
to the same recurrent time slot in every
TDM frame, each data stream is assigned
time slots (of fixed length) or data frames
(of variable lengths) that often appear to
be scheduled in a randomized order, and
experience varying delay (while the delay
is fixed in TDM).
1
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Statistical time division multiplexing - Comparison with static TDM
Statistical multiplexing allows the
bandwidth to be divided arbitrarily
among a variable number of channels
(while the number of channels and the
channel data rate are fixed in TDM).
1
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Statistical time division multiplexing - Comparison with static TDM
1
Statistical multiplexing ensures that
slots will not be wasted (whereas TDM
can waste slots). The transmission
capacity of the link will be shared by
only those users who have packets.
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Statistical time division multiplexing - Comparison with static TDM
1
Static TDM and other circuit switching
is carried out at the physical layer in
the OSI model and TCP/IP model,
while statistical multiplexing is
carried out at the data link layer and
above.
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Statistical time division multiplexing - Channel identification
In statistical multiplexing, each
packet or frame contains a
channel/data stream identification
number, or (in the case of datagram
communication) complete destination
address information.
1
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Statistical time division multiplexing - Usage
1
Examples of statistical
multiplexing are:
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Statistical time division multiplexing - Usage
1
The MPEG transport stream for digital
TV transmission. Statistical
multiplexing is used to allow several
video, audio and data streams of
different data rates to be transmitted
over a bandwidth-limited channel (see
#Statistical multiplexer). The packets
have constant lengths. The channel
number is denoted Program ID (PID).
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Scheduling (computing) - Scheduling disciplines
In packet-switched computer
networks and other statistical
multiplexing, the notion of a
scheduling algorithm is used as an
alternative to first-come first-served
queuing of data packets.
1
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Transmission Control Protocol - Development
1
The redundancy offered by Multipath TCP
in the context of wireless networks
enables statistical multiplexing of
resources, and thus increases TCP
throughput dramatically
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Time-division multiplexing - TDM versus packet-mode communication
Bandwidth reservation distinguishes timedivision multiplexing from statistical
multiplexing such as packet mode
communication (also known as 'statistical
time-domain multiplexing', see below) i.e. the
time slots are recurrent in a fixed order and
pre-allocated to the channels, rather than
scheduled on a packet-by-packet basis.
Statistical time-domain multiplexing
resembles, but should not be considered the
same as time-division multiplexing.
1
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EVDO - TIA-856 Rev. B
1
* Reduced latency by using statistical
multiplexing across channels—
enhances the experience for latency
sensitive services such as gaming,
video telephony, remote console
sessions and web browsing.
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Digital radio - Broadcast standards
The latter allows one wideband radio
signal to carry a statistical
multiplexing|multiplex consisting of several
radio-channels of variable bitrate as well
as data services and other forms of media
1
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Three way handshake - Development
1
The redundancy offered by Multipath
TCP in the context of wireless
networks
[http://portal.acm.org/citation.cfm?i
d=1794199 TCP with feed-forward
source coding for wireless downlink
networks] enables statistical
multiplexing of resources, and thus
increases TCP throughput
dramatically
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Network Neutrality - Over-provisioning
Over-provisioning is a form of
statistical multiplexing that makes
liberal estimates of peak user demand
1
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IMT Advanced - Principal technologies
* Frequency-domain statistical
multiplexing, for example (OFDMA) or
(Single-carrier FDMA) (SC-FDMA,
Linearly precoded OFDMA, LP-OFDMA)
in the uplink: Variable bit rate by
assigning different sub-channels to
different users based on the channel
conditions
1
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
OFDMA - Characteristics and principles of operation
1
OFDMA can be seen as an alternative to
combining OFDM with time division
multiple access (TDMA) or time-domain
statistical multiplexing, i.e. packet
mode communication. Low-data-rate
users can send continuously with low
transmission power instead of using a
pulsed high-power carrier. Constant
delay, and shorter delay, can be
achieved.
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Cable Internet access - Shared bandwidth
This arrangement allows the network
operator to take advantage of statistical
multiplexing, a Bandwidth
(computing)|bandwidth sharing technique
which is employed to distribute bandwidth
fairly, in order to provide an adequate level
of service at an acceptable price
1
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Long-tail traffic - Network performance
1
* Worst cases in statistical
multiplexing
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Channel access method - Packet mode multiple-access
1
Due to its random character it can be
categorised as statistical multiplexing
methods, making it possible to provide
dynamic bandwidth allocation
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GPRS - Multiple access schemes
This is combined with time domain
statistical multiplexing; i.e., packet mode
communication, which makes it possible
for several users to share the same
frequency channel
1
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Transport layer - Analysis
1
This involves statistical multiplexing of data
from different application processes, i.e
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Asynchronous communication - Data link layer and higher
1
Asynchronous communication at the data
link layer or higher protocol layers is
known as statistical multiplexing or packet
mode communication, for example
asynchronous transfer mode (ATM). In this
case the asynchronously transferred
blocks are called data packets, for
example ATM cells. The opposite is circuit
switched communication, which provides
constant bit rate, for example ISDN and
SONET/SDH.
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G-PON - Upstream bandwidth allocation
Through dynamic bandwidth
allocation (DBA), a PON can be
oversubscribed for upstream traffic,
according to the traffic engineering
(telecommunications)|traffic
engineering concepts of statistical
multiplexing
1
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Sirius Satellite Radio - Signal architecture and early prototypes
1
The studio encoder was a result of Bell
Labs efforts in statistical multiplexing of
perceptual audio coded signals, a cousin
of the MP3 standards
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Digital Audio Broadcasting - Protocol stack
1
From an OSI model protocol stack viewpoint,
the technologies used on DAB inhabit the
following layers: the audio codec inhabits the
presentation layer. Below that is the data link
layer, in charge of packet mode statistical
multiplexing and frame synchronization.
Finally, the physical layer contains the errorcorrection coding, OFDM modulation, and
dealing with the over-the-air transmission and
reception of data. Some aspects of these are
described below.
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Linux Process Scheduler - Scheduling disciplines
1
In packet-switched computer networks and
other statistical multiplexing, the notion of
a 'scheduling algorithm' is used as an
alternative to FIFO (computing)|first-come
first-served queuing of data packets.
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Virtual circuit
1
* varying load from other users sharing
the same network resources by means
of statistical multiplexing, etc.
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Asynchronous
At the higher data link layer of
communication, 'asynchrony' is synonym
of statistical multiplexing, such as in
packet mode
1
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Orthogonal frequency-division multiple access - Characteristics and principles of
operation
1
OFDMA can be seen as an alternative to
combining OFDM with time division
multiple access (TDMA) or time-domain
statistical multiplexing communication.
Low-data-rate users can send
continuously with low transmission power
instead of using a pulsed high-power
carrier. Constant delay, and shorter delay,
can be achieved.
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
BBC HD - Technical Specifications
1
Following the launch of BBC One HD on 3
November 2010, both the new channel
and BBC HD were Statistical
multiplexing|statistically multiplexed on the
satellite feeds
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Radio resource management - Dynamic radio resource management
1
* Dynamic bandwidth allocation using
resource reservation multiple access
schemes or statistical multiplexing,
for example Spread spectrum and/or
packet radio
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Statistical multiplexing
1
When performed correctly, statistical
multiplexing can provide a link
utilization improvement, called the
statistical multiplexing gain.
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Statistical multiplexing
1
Statistical multiplexing is facilitated through
'packet mode' or 'packet-oriented'
communication, which among others is
utilized in packet switched computer
networks. Each stream is divided into packets
that normally are delivered asynchronously in
a first-come first-served fashion. In alternative
fashion, the packets may be delivered
according to some scheduling discipline for
fair queuing or differentiated and/or
guaranteed quality of service.
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Statistical multiplexing
1
Statistical multiplexing normally implies
on-demand service rather than one that
preallocates resources for each data
stream. Statistical multiplexing schemes
do not control user data transmissions.
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Statistical multiplexing - Comparison with static TDM
Time domain statistical multiplexing
(packet mode communication) is similar
to time-division multiplexing (TDM),
except that, rather than assigning a data
stream to the same recurrent time slot in
every TDM data frame|frame, each data
stream is assigned time slots (of fixed
length) or data frames (of variable
lengths) that often appear to be scheduled
in a randomized order, and experience
varying delay (while the delay is fixed in
TDM).
1
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Statistical multiplexing - Usage
1
* The MPEG transport stream for digital
TV transmission. Statistical multiplexing is
used to allow several video, audio and
data streams of different data rates to be
transmitted over a bandwidth-limited
channel (see Statistical multiplexer). The
packets have constant lengths. The
channel number is denoted Program ID
(PID).
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Multiple access - Time division multiple access (TDMA)
1
Due to its random character it can be
categorised as statistical multiplexing
methods, making it possible to
provide dynamic bandwidth allocation
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Weighted fair queuing
1
'Weighted fair queueing' (WFQ) is a
data packet scheduling
(computing)|scheduling technique
allowing different scheduling
priorities to statistical
multiplexing|statistically
multiplexed data Flow (computer
networking)|flows. Weighted fair
queueing is popular because it
approximates generalized processor
sharing to within one packet
transmission time, regardless of the
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Cell relay
1
In computer networking, 'cell relay' refers
to a method of statistical
multiplexing|statistically multiplexing small
fixed-length packet (information
technology)|packets, called cells, to
transport data between computers or kinds
of network equipment. It is an Reliability
(computer networking)|unreliable,
connection-oriented packet
switching|packet switched data
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Packet switched network - Overview
Packet switching features delivery of
variable bitrate data streams (sequences
of packets) over a computer network
which allocates transmission resources
as needed using statistical multiplexing
or dynamic bandwidth allocation
techniques. When traversing network
adapters, switches, routers, and other
network nodes, packets are buffered and
queued, resulting in variable delay and
throughput depending on the network's
capacity and the traffic load on the
1
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Asynchrony
1
At the higher data link layer of communication,
asynchrony is synonym of statistical
multiplexing
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Kermit (protocol) - Technical
1
On connections over RS-232 Statistical
multiplexing|Statistical Multiplexers
where some ASCII#ASCII control
characters|control characters do not
transmit, Kermit can be configured to
work, unlike protocols like XMODEM
that require all 256 bytes be
transmittable.
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Time-multiplexing - TDM versus packet-mode communication
1
Bandwidth reservation distinguishes timedivision multiplexing from statistical
multiplexing such as statistical time
division multiplexing i.e. the time slots are
recurrent in a fixed order and pre-allocated
to the channels, rather than scheduled on
a packet-by-packet basis.
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Dynamic bandwidth allocation
1
'Dynamic bandwidth allocation' is a
technique by which traffic bandwidth
in a shared telecommunications
medium can be allocated on demand
and fairly between different users of
that bandwidth. This is a form of
bandwidth management, and is
essentially the same thing as
statistical multiplexing. Where the
sharing of a link adapts in some way
to the instantaneous traffic demands
of the nodes connected to the link.
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Max-min fairness
1
In best-effort statistical multiplexing, a
first-come first-served (FCFS)
scheduling policy is often used. The
advantage with max-min fairness over
FCFS is that it results in traffic shaping,
meaning that an ill-behaved flow,
consisting of large data packets or
bursts of many packets, will only
punish itself and not other flows.
Network congestion is consequently to
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Max-min fairness
1
Fair queuing is an example of a maxmin fair packet scheduling algorithm
for statistical multiplexing and best
effort packet-switched networks, since
it gives scheduling priority to users
that have achieved lowest data rate
since they became active. In case of
equally sized data packets, roundrobin scheduling is max-min fair.
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Data link connection identifier
1
Frame Relay networks use DLCIs to Statistical
multiplexing|statistically multiplex frames
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Digital terrestrial television in the United Kingdom - Use of multiplexing technology
1
*Multiplexes can make use of statistical
multiplexing at the MPEG video coder
whereby the bitrate allocated to a
channel within the multiplex can vary
dynamically depending on how difficult
it's to code the picture content at that
precise time, and how much demand
there is for bandwidth from other
channels
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Digital terrestrial television in the United Kingdom - Improvements in compression
technology
Developments in statistical
multiplexing, improved compression
technology, and, in some cases, an
acceptance of lower quality or lower
resolution broadcasts, allowed
gradual increases in the number of
services carried on digital terrestrial
television multiplexes.
1
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Muxer - Types of multiplexing
Multiple variable bit rate digital bit
streams may be transferred efficiently
over a single fixed Bandwidth (signal
processing)|bandwidth channel by
means of statistical multiplexing. This
is an asynchronous mode timedomain multiplexing which is a form
of time-division multiplexing.
1
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
Muxer - Relation to multiple access
A multiplexing technique may be
further extended into a multiple access
method or channel access method, for
example TDM into time division
multiple access (TDMA) and statistical
multiplexing into carrier sense multiple
access (CSMA). A multiple access
method makes it possible for several
transmitters connected to the same
physical medium to share its capacity.
1
https://store.theartofservice.com/the-statistical-multiplexing-toolkit.html
KSCI - Digital channels
1
KSCI has subleased several of its digital
subchannels to other broadcasters.
Station management believes that six
digital subchannels can fit into the
spectrum, using statistical multiplexing.
The station's digital channel is Multiplex
(TV)|multiplexed:
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