Multimedia Applications and End Systems (Devices)

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14 Νοε 2013 (πριν από 3 χρόνια και 4 μήνες)

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1

Multimedia Applications and End Systems (D
evices)



Chao
-
kai Ching, George Lin and
Yevgeniy Razuvayev

Department of Computer Science and Engineering, The Ohio State University

(ching.17, lin.539, razuvayev.1)@osu.edu



Abstract


With current advanced in
network
,
multimedia
,
computer engineering technologies, in the future, it is
highly possible that our desktop computers will not be
the major end systems running multimedia applications.
This paper focuses on three non
-
desktop end systems
and discusses how

they support multimedia through
network in their own
special

environment
, which
provides different challenges for the device
designer
s.
Additionally, the hardware of each end system is
introduced with discussion of how the problems for
providing multimedi
a support in each end system is
solved, or at least compromised.


1. Introduction


With current advanced in
network
,
multimedia
,
computer engineering technologies, in the future, it is
highly possible that our desktop computers will not be
the major end s
ystems running multimedia applications.

This paper focuses on three non
-
desktop end
systems and discusses how they support multimedia
through network in their own
special

environment
,
which provides different challenges for the device
designer
s. Additiona
lly, the hardware of each end
system is introduced with discussion of how the
problems for providing multimedia support in each end
system is solved, or at least compromised.

The first category of devices introduced is about
TV
over the Internet
,
which

ena
ble users to watch TV
anywhere. Following the TV
over the Internet
is the
ZEUS
-
TS
system, which

allows surgeons to
perform

remote

surgery. Finally, the technology and
framework

of telerobotics are discussed.


2. Entertainment


One of the most common and
most profitable uses
for multimedia is in the area of entertainment. Music,
pictures, movies, and video games have been sources
of revenue for many companies for years. With the
growth of the Internet, more and more resources are
being used to send multime
dia to computers through
the Internet. As the amount of bandwidth available to
users steadily increased over the years, the amount of
bandwidth being used for multimedia entertainment has
also increased. With broadband Internet available in
the home of man
y users, video files are becoming more
common on the Internet. Videos can be downloaded or
streamed by home viewers and some devices have been
created to expand the available online content for the
video watcher on the go.


2.1 TV Over the Internet


The a
bility to watch live TV over the Internet has
been a previously unexplored idea. In recent years,
several companies have developed devices to allow
people to watch live TV programs over the Internet.
These devices take a TV signal and compress the video
to

send over the Internet for a client to watch. The idea
behind sending TV over the Internet is to allow viewers
to watch live TV anywhere that there is a high
-
speed
Internet connection. This could allow a frequent
traveler to watch local TV while they are
away from
home so that they will never have to miss a sports game
or their favorite TV show. TV over the Internet also
allows for people to watch TV at Internet hot spots that
can be found in many places around the world
including cafes, malls, and even s
ome McDonald’s
restaurants. TV Over the Internet is also used to watch
TV from far away locations such as other countries. A
European soccer fan living in the United States of
America can use TV Over the Internet to watch all of
his favorite team’s games w
hile being on the other side
of the Atlantic Ocean. TV2Me, Slingbox, and Sony
LocationFree are three hardware devices that act as live
TV video servers that can send live TV video over the
Internet. Orb is a software application and a service for
Windows X
P that allows a user to use his home PC to
send live TV video over the Internet.


2.1.1 TV2Me


The TV2Me is one of the first devices created to
allow for TV over the Internet. Its creator, Ken
Schaffer, also invented the wireless microphone and
the wireles
s guitar. Schaffer’s motive for creating the

2

TV2Me was to be able to watch live Russian TV while
he was in America and to watch live American TV
while he was in Russia. While streaming video over the
Internet is not new technology, the quality of streaming

video tends to be lackluster. The impressive aspect of
Schaffer’s invention is the quality of the video that is
sent across the Internet. Robert Cringely states that
“…at 384 kilobits
-
per
-
second using hardware encoding
only on the sending end (the receive
r is software
-
only)
and he [Ken Schaffer] can watch perfectly viewable
television that has run through 20+ hops from
Moscow”[3].




Fig. 1. TV2Me connection [1]


The TV2Me is an appliance that is connected to a
TV signal and an Internet connection. The T
V2Me can
then send the video to a computer with an Internet
connection and the necessary software. The video is
sent over the Internet so the viewing computer can be
located anywhere in the world as long as it is connected
to the Internet. The TV2Me hardwa
re is actually a Dell
PC with a custom video capture card to preprocess and
encode the video using an MPEG
-
4 encoder. The
details of the preprocessing were not revealed but the
preprocessing is credited for the superior quality of the
TV2Me streaming video

as the MPEG
-
4 encoding is
used in other video streaming applications. MPEG
-
4 is
an open international standard for multimedia and does
not refer to a specific video codec.

Many multimedia codecs are MPEG
-
4 codecs and
the following table lists some of tho
se codecs as well as
their applications. The newest MPEG
-
4 codec is AVC
and it is designed for high quality video and is even
used for Internet video. Apple Quicktime, a common
application that is used by many Internet sites for
video, is one of the applic
ations that uses AVC.



Fig. 2. MPEG
-
4 Codecs [4]


Despite the advancements in sending live TV video
over the Internet made by TV2Me there are still several
setbacks. TV2Me is only a point
-
to
-
point system where
there can only be one viewer per TV2Me syste
m.
TV2Me also requires a 384 kpbs upstream bandwidth
for the TV2Me system with a recommended 512 kpbs
or 768 kpbs upstream bandwidth to allow for growth.
Many broadband connections still do not have an
upstream bandwidth of over 384 kpbs so it will still b
e
inaccessible to many broadband users. There is also a
buffering delay when the channel is changed in
TV2Me, which can hinder the viewing experience, as
channel surfing will take longer. Viewers also connect
to the TV2Me by specifying the IP address so us
ers
without a static IP address may have to constantly
lookup and remember the IP address for the TV2Me in
order to connect to it. The final hurdle preventing
TV2Me from becoming a common household
appliance is its price tag of $4,750.00 for a pre
-
configur
ed system with a potentially higher price tag
for a custom designed system. The high quality
streaming TV video of TV2Me comes at a high cost
but Schaffer is hoping to reduce the cost of the TV2Me
to under $1000 in the recent future but for the moment
TV2M
e is not a mass market offering. Other
companies have also entered the TV over Internet
market and offer their own solutions to allow for
remote viewing of TV programs to the mainstream
market.


3

2.1.2 Slingbox


The Slingbox is one of the competitors of TV
2Me
and offers a device that sends TV video over the
Internet at a cost of $249.99. The Slingbox works in a
similar manner to TV2Me but it encodes the video into
Windows Media 9.0 format and uses a proprietary QoS
software that optimizes the video based on

the
available bandwidth. This stream optimization is code
named “Lebowski” and is designed to change the video
parameters in real time by monitoring the network and
making changes depending on the media, network, and
the viewing system.

The Slingbox uses

a technology called
Slingstream™
to reduce delay when sending control signals since the
Slingbox does not use a traditional buffering scheme.
This means that changing channels will not result in as
much of a delay since the video does not need to be
buffered. The technology a
lso analyzes the video and
audio streams and sends it back to the encoder to alter
the compression process depending on the type of
video being viewed such as if it is a high motion
sporting event or a low motion news cast.



Fig. 3. Adaptive Compression

[8]


Sling media, the creators of the Slingbox, also
provide a service to find the IP address of the Slingbox
system when away from home. This free service is
called Finder and works by having servers remain in
constant contact with the Slingbox and havin
g users
connect to their Slingbox through the Finder service.
By using the Finder service the user does not have to
remember the IP address of the Slingbox to connect to
it.

The Slingbox is supposedly capable of working with
a mere 50 kpbs bandwidth but to

get a decent quality
video stream it is recommended to have a transfer rate
of 220 to 400 kpbs. The Slingbox can also only have
one computer connect to it to protect the rights of
copyright holders. The Slingbox attempts to bring live
TV over the Internet

to the mainstream user and it is
available for purchase in some retail stores such as
CompUSA or Bestbuy. It has features that make it
more user
-
friendly than the TV2Me and is offered at a
much lower price. However the video quality of the
Slingbox is not

as impressive as the TV2Me and Rik
Farlie described the video quality of the Slingbox as,
“…
just a little better than the quality of streaming Web
videos” [7].


2.1.3 Sony LocationFree


The first entry by a major consumer electronics
company into the T
V over Internet market is the Sony
LocationFree. The Sony LocationFree is available in
different packages and can be purchased as a base
station alone or in a package where the base station is
included with a LocationFree TV. The LocationFree
TV is a LCD T
V that can function as the receiver of
the video stream and can also be used to surf the
Internet. The LocationFree requires a bandwidth of at
least 300 kpbs for good quality video. The base station
alone costs $349.99 and has similar features to the
Sling
box. Like the TV2Me, the LocationFree also uses
a MPEG
-
4 encoding and it incorporates a DNS service
integrated into its LocationFree Player Pak and
LocationFree TV so the user doesn’t need to remember
the IP address of the base station. The LocationFree
ca
n have four devices registered to use it and can work
with a PC, Sony PSP, or the Sony LocationFree TV.
Despite being able to work with up to four devices, the
base station can still only send video to one device at a
time. The LocationFree is also designe
d to work on
both a home network or over the Internet and has
superior quality to TV2Me when both are used within a
home network. The TV2Me has superior video quality
when both devices are used to send TV over the
Internet.


2.1.4 Comparing the Devices


Vi
deo quality is a subjective evaluation that varies
depending on the viewer. The typical way to determine
which device has better video quality is to compare the
videos from each devices side by side and determine
which video looks better since there is no
quantitative
measurement for video quality. Of the three hardware
devices designed for sending TV over the Internet, the
TV2Me is considered to have the best video quality.
The Slingbox and the LocationFree provide better than
standard streaming video qual
ity but do not quite match
the video quality of TV2Me when using the same
amount of bandwidth. They also come at a significantly
lower price than the TV2Me. The table below provides
a summary of the different devices that can send live
TV over the Internet
. The listed bandwidth is the
minimum recommended bandwidth for good quality
video and the quality description is in relation to other
video streaming applications.


4






Table 1. TV Over the Internet Device Summary


2.1.5 Orb


The previously described d
evices are specific
hardware solutions for sending TV over the Internet.
Orb Networks provides a software option for TV
enthusiasts to view TV over the Internet if the user’s
home PC meets the hardware and software
requirements to use Orb. To stream TV ove
r the
Internet, the user needs to have a Windows XP
operating system and a compatible TV Tuner with a
hardware MPEG
-
2 encoder. The user then downloads
the Orb software and registers with Orb so that they
can log in to the Orb site and connect to their home

system running the Orb software from a remote system.

The remote system can just use a Web Browser and a
video player such as Windows Media Player or Real
Player to watch the TV video. Orb also allows the user
to stream other digital media from their hom
e PC such
as photos, music, or videos. 300 kpbs can provide
standard TV resolution using standard compression
when using the Orb service. The best feature about the
Orb software and service is that it is free if the user’s
system already meets the requirem
ents and it can also
work compatible cell phones and PDAs. The Orb
software enables users to use their home PC as a video
server and allows the user to view their multimedia
files using other devices besides just a computer.


3
.
Remote Surgery


Remote Su
rgery, also named as telesurgery, enables
the

doctor to perform surgery on a patient even
when

they are not physically in the same location

[13]
.

The
ability to perform telesurgery depends on the advance
in both technologies of telecommunication and
telero
botics.


3
.1.
Operation Lindbergh


The project of Operation Lindbergh, the first
transatlantic

remote surgery in 2001, serves as a perfect
example to demonstrate the connection between
telerobotics and telecommunication
.

Section three will
cover telerobot
ics in more detail; this section will focus
on the
telecommunication
, and only mention
teleroboitcs part when needed.







3
.
2
.
The ZEUS
TM

System


Zeus
TM

is a robotic surgical system to perform
endoscopic microsurgical procedures, a type of
minimally
-
inv
asive surgery.

Although the Zeus
TM

system itself can not be used automatically to perform
remote surgery, its master
-
slaver configuration allows s
the project designer to use it as a drop
-
in component
without
modifying

the robotic system and preserve its
f
ail
-
save features. The system is composed of two
major parts, the master console where the surgeon
performs the surgery and a set of robotic arms and
camera
-
control equipment mounted on the operating
room table [2]. Figure 1 shows the surgeon
-
site and
Figu
re 2 depicts the patient
-
side equipment.




Fig. 4. Surgeon

side equipment [13]


Device
Encoding
Bandwidth
DNS
Quality
Compatible Receivers
Price
TV2Me
MPEG-4
384 kpbs
No
Best
Personal Computer
4,750.00
Slingbox
Windows Media 9.0
220 kpbs
Yes
Better
Personal Computer
249.99
LocationFree
MPEG-4
300 kpbs
Yes
Better
Personal Computer, Sony
PSP, Sony LocationFree TV
349.99

5



Fig. 5. Patient
-
side equipment [13]


3
.
3
.
The Zeus
-
TS System


In order to support remote surgery, following
equipments have been added. Two standard Pentium
-
based compute
rs running VxWorks real
-
time O.S. with
100 base
-
T
Ethernets

are included on surgeon and
patient side, and the patient and surgeon
equipment
s
are connected to the computers. Figure 3 indicates the
modified version of the ZEUS system [13].




Fig. 6. Teles
urgical system after separation [13]


In the modified system, all the signals generate from
the surgeon console and feedback signals from the
patient side are communicated through the network
connection. All the
video

codec is processed through
different h
ardware and transferred through the network
connection.


3.4
.
Network Communications


T
he surgeon
-
side and

p
atient
-
side subsystems are
connected
through

a dedicated 10 Mb/s CBR ATM
circuit with OC
-
3 fiber. Standard UDP/IP
protocol

is
used for network trans
mission.


3
.
5
.
Bandwidth Allocation


In order to achieve on time delivery of t
he
high
quality
video signal

in PAL format generated by
the
endoscopic camera
, the technique of over provision
is
used.

Seventy percent of bandwidth is reserved for
video transm
ission. Other bandwidth is used by robot
control signals transmission, which, including UDP/IP
overheads and ATM/SONET framing as well as all
embedded
serial

communications streams, are less than
60 Kb/s [13].


3.6
.
Package Format


Included in the data pa
ckage is the information of
robotic operation e.g. sensing and positioning the
robots, and that of recovery from communication losses.
Information used to
maintain

the fail
-
safe behavior of
the Zeus system in case of communication breakdown
is also added i
nto the package. In order to detect errors
and maintain order of the packages, each package has a
package checksum and a
sequence number
.

Both
surgeon and patient side machine record the statistics of
package arrival as an indicator of communications
succe
ss and include the information within in the package
sent [14].

For all robot
-
related data in the packet, the strict in
-
order delivery is not a concern. The only requirement
for the packet is that it is not corrupt, i.e. passing the
checksum, and is newer
than the previous received one.
Any robot
-
related data fulfill the above requirement are
sufficient to provide robot position and feedback
information

for
necessary

robot operation. The
advantage

of sending all robot
-
related data in
packets
in
an absolute
form is that packages
can be

“dropped or even
corrupted (hence discarded after error

detection) due to
communication bit errors without

unduly affecting the in
-
progress operation as long as a

certain minimum arrival

rate of good packets is maintained

[14]
.



3
.
6
.1.
Surgeon
-
site
package

format
. The Zeus system
is designed in the master
-
slave fashion, and the
surgeon
-
site serves as the master. Surgeon
-
site sends
the data about machine console operation and receives
feedback data from
patient

side. Figure 4 sh
ows the
robot control
related

data in surgeon
-
site package.



6



Fig. 7. Surgeon site robot control data [14]


3.6
.
2
.
Patient
-
site
package

format
. Comparing to the
surgeon
-
site
package
, less data are sent from the
patient
-
site to the surgeon
-
site. Figure 5
shows the
robot control
related

data in patient
-
site package.




Fig. 8. Patient
-
site robot control data [14]


Additional to robot control data, both surgeon and
patient site package contains the following information
(indicated in figure 6) to support an
d enhance
communication
reliability
.




Fig. 9. Other data for stable communication [14]


3.7
.
Communication anomalies and their
solutions


3.7
.1.
Delayed Packets.
For any real time application,
timely delivery of process data is the most important
consi
deration. In the remote surgery application, due to
the high quality video requirement, the project designer
decides to use over provision to
achievement

the
latency requirement. The communications latency on
the ability of a laparoscopic surgeon to perfor
m various
surgical

manipulations should not exceed

700 ms

[13].
The project has limit latency within 330 ms.


3.7
.
2
.
Single
-

or multiple
-
bit errors in a packet or
Fragment.

The Zeus
-
TS does not provide specially
designed
protocol

to handle bit errors, but
relies on the
pre
-
built error checking facilities in the network. One
of the reasons for lacking customized error detecting
protocol is
that

the probability of a bit error in current
high quality optical fiber links is less than 10
-
9
.
Therefore, at ATM lev
el and UDP level, header
checksum is used; at Ethernet level, CRC is used [13].


3
.
8
.
Dropped packets and out of order packets


Because
the designer use
s UDP/IP protocols, the
ability

of detecting dropped packets and out of order
packets based on the seque
nce number is put upon the
application layer running in the two telecommunication
computers in the surgeon and patient side. Additionally,
the system
requires

that each package
received

must be
acknowledged [13].


4. NeuroMaster


NueroMaster (NM) is anothe
r telesurgical system
for minimally invasive frameless neurosurgery. The
major components of the system are similar to the
Zeus
-
TS, which also includes the robot arm with its
controller, the 3D vision system, the remote control

7

system, an the network. Figu
re 10 depicts the structure
of the system [15].



Fig. 10. Structure of NeuroMaster system [15]


The major difference between NeuroMaster and
Zeus
-
TS is the network component. For Zeus
-
TS,
expensive, dedicated ATM is used to provide enough
bandwidth for h
igh
quality

video in PAL format.
However, the use of the dedicated
network

is the major
reason why the gall bladder surgery requires $1 million
to perform comparing to a typical one costing only
$2,000. On the
other

hand, the NeuroMaster can
perform the re
mote surgery over ADSL and Modem.


4.1. The Video Codec in NeuroMaster


The main reason why NM is able to use ADSL
instead of ATM depends on the preprocessing of the
video image. Totally, there are three resources of the
visual information, one video image

for
global

vision,
and two video images for local visions. In order for
timely delivery of the three video images, all the three
video images are first
captured as
white and black 8bit
video BMP images. Depending on the sources of the
visual
information
,
the
global

one is sampled from PAL
into CIF and two video images from local visual
information are sampled from PAL into QCIF.
Finally
,
all the BMP images are converted into JPEG format
before [15].


4.2. Further investigation for the ADSL in
NeuroMaster


However, the comparison made here requires further
investigations. Even though both of the system is
designed

for minimal invasive surgery, the two remote
surgeries performed are totally different, one
for the

gall bladder surgery, and one for cerebral
-
he
morrhaged
disease. The different types of the surgery
require

different medical data to be processed during the
communication, which lead to the difference complex
in network and
multimedia

support. For instance, the
video quality
requirement

in NeuroMaste
r system is
lower than the Zeus
-
TS. Second, Zeus
-
TS performs a
transatlantic

remote
surgery

between France and USA,
but NeuroMaster performs the surgery between Beijing
and Shenyang instead. The geological difference
affects the choice of the network consi
derably.
Therefore, whether NeuroMaster has developed a more
sophistic scheme in terms of network and multimedia
support remains
debatable
.


5
.
Robotics Environment and Telerobotics


Robotic Environment and Telerobotics is one of the
growing and expanding
fields of research today. Today
we can see robots being employed on the jobs and
places where it is deemed too dangerous for humans to
venture to. Army uses remote robots to fly spy planes
missions over hostile territories of Iraq and
Afghanistan. Police u
ses remote robots to resolve
hostile situations such as exploding device
disarmament and subduing a suspect in barricaded
situation. Even NASA uses remote robots to explore
the distance planets in our solar systems. In this
section, the general architectur
e and requirements of
remote robotics will be discussed and presented

[16]
.




Fig. 10.


5
.1.
ATM Network Architecture


Remote robotics is the primary example of ATM
(Asynchronous Transfer Mode) Network, and uses end
-
to
-
end comm
unication between the master side and the
slave side. This communication must be high speed and
robust to accommodate the requirements established by
remote robotics systems.

The master side is the end
-
point where human
operator is stationed and operates t
he slave side, or the
robotic side.


8

The slave side is the end
-
point where robotic system
is present and continuously sends the state information
back to the master side.


5
.2.
Architecture of Telerobotics




Fig. 11. [17]


The a
rchitecture of telerobotics depends on the
complexity of remote robot system and its tasks.
However, almost all remote robots system architectures
share the following common characteristics.

The architecture of the master side is relatively
simple and cons
ists of a human operator and a terminal
display or control device. In most cases, the terminal
and control device would be a software application,
which runs on the operator’s workstation. Using the
terminal and control device, operator is able to send
com
mands to the robot. The terminal is then used to
receive and view responses that robot sends back. The
terminal usually displays the information about the
current state of the robot, as well as any video feed
received from a robot including the audio feed,

if one is
present.

The architecture of the slave side, or the robot side,
consists of robotic system, which is the robot itself.
They can be anything from a single robotic arm that
picks up objects and moves it around, to complex
robotic systems that move

around. The major
component of any robotic is the sensor unit that gathers
all the information regarding the state of the robot as
well as the environmental variables and information of
the environment in which the robot is currently present.
This informa
tion is then transmitted back to the
operator’s terminal. In addition, this information can
include the video and audio feeds, which allows the
operator for better assessment of the current state of the
remote robotic system and its environment.


5
.3.
Requ
irements of Telerobotics


In the previous section, three major components of
telerobotics’ architecture were identified, the sensor,
the terminal, and the video feed. All three of these
components play the vital role in the telerobotics
architectures and a
ll of them have unique requirements
that must be satisfied to ensure a functional operation
of remote robotic system

[17]
.


5
.3.1. Sensor and Operator Terminal
Requirements


The sensor is one of the major units of remote
robotic unit. It gathers and stores

information about the
current state of the robotic unit, until that information
can be relayed back to the operator.

While the idea of rampaging robots can be quite
amusing, we all know how it is frustrating when even
the simplest of devices refuses to be
have as expected. It
is for this simple reason that sensor must be accurate
and redundant in its collection of information. One of
the major characteristic of the sensor unit is that it must
have a high degree of reliability. When sensor transmits
the info
rmation back to the terminal, it must insure that
no data loss occurred. If data lost detected, it must be
minimized as much as possible. The reason for this is
to minimize and eliminate the operator error due to
outdated and inaccurate information being s
ent from
the remote robotic system. The operator must trust the
information he/she is provided to operate the robotic
unit at is peak efficiency and safety.

Second major characteristic of the sensor unit is to
provide accurate and high precision informatio
n.
However, it is an inheriting flaw in all binary
computers systems that a simple decimal number of
“0.2” (
5
1
) cannot be represented as a finite number in
binary number system. Therefore, computer systems
must do their best to approxi
mate such numbers. The
accuracy in remote robotics units is important because
it can mean a fine line between success and failure if
robotic unit must navigate and complete fine precision
tasks such as high
-
explosives disarmament or complex
navigation.

The

final major characteristic of the sensor unit is to
provide minimum end
-
to
-
end delay of all information it
sends out to the terminal and the operator, and vice
versa. It is crucial in most environments, to which
remote robotic units are deployed, that ope
rator should
control the remote robotic unit in real time, and that
means to minimize end
-
to
-
end delay as possible. Back
to the example of explosives disarmament, the time is
crucial and so the operator must be able to send

9

commands to the remote robotic s
ystem without
experiencing any soft of delay. The same condition
applies to remote robotic spy and reconnaissance
planes where accuracy and instantaneous delivery of
data is of major concern

[17]
.


5
.3.2. Video and Audio Feed
Requirements


The second major

units of remote robotics systems
are video and audio feeds that robots send to the
operator’s terminal.

Video and audio are gathered by the remote robotic
system and send to the operator terminal to allow
operator for a better understanding of the environ
ment
the remote robotic system is located. In most cases, the
video and audio is optional, however they provide an
expanded and crucial information that sensor unit can
not, and they also serve as a back
-
up alternative if
sensor unit fails to replay accur
ate information back to
the operator terminal.

As with sensor unit, video and audio feed must try
to minimize the loss of video and audio data. While
video and audio data is of less importance then sensor
data, it is still crucial to provide an operator wi
th a
clear and understandable video and audio, since
operator maybe relaying on it as well as the sensor data
to operate a remote sensor unit.

In addition, end
-
to
-
end delay must also be at a
minimum to provide a smooth video and audio, and to
minimize jitt
ers. However, unlike the sensor data, the
quality and rate of video and audio data can be adjusted
to allocate for delay in the network. Thus, allowing
video and audio feed can be more flexible

[17]
.


5
.4.
Telerobotics Network


As we discussed the architec
ture and the
requirements of telerobotics and remote robotic
systems, the last question remains of what kind of
network environment is needed to support such end
systems.

For sensor unit communication, where the emphasis
is on reliability and efficiency, t
he TCP protocol would
be sufficient to support all communication between
sensor unit and operator terminal. The TCP protocol
would guarantee a fair transfer of sensor data and in
-
order arrival with minimum of delay and loss, which
will fulfill our requirem
ents for reliability and
efficiency.

For video and audio feed transfer, where the
emphasis is on the delivery, the UDP protocol would
be sufficient. The UDP protocol applies best effort, and
since both video and audio data should be transmitted
at best eff
ort and allowed to have some jitters, it is
sufficient to use simpler protocol, such as UDP, to
transmit video and audio feed

[16]
.


References


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10

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