What is WIMAX ?

bottlelewdMobile - Wireless

Dec 12, 2013 (3 years and 4 months ago)

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What is WIMAX ?


WiMAX is an IP based, wireless broadband
access technology that provides performance
similar to 802.11/Wi
-
Fi networks with the
coverage and QOS (quality of service) of
cellular networks. WiMAX is also an acronym
meaning "Worldwide Interoperability for
Microwave Access (WiMAX).

What is WIMAX ?


WiMAX

(
Worldwide Interoperability for
Microwave Access
) is a
telecommunications

protocol that provides fixed and mobile Internet
access. The current WiMAX revision provides
up to 40

Mbit/s with the
IEEE 802.16m

update
expected to offer up to 1 Gbit/s fixed speeds.

What is WIMAX ?



The name "WiMAX" was created by the
WiMAX Forum
, which was formed in June
2001 to promote conformity and
interoperability of the standard. The forum
describes WiMAX as "a standards
-
based
technology enabling the delivery of
last mile

wireless broadband access as an alternative
to cable and DSL".

What is last mile operation ?


The
"last mile"

or
"last
kilometer
"

is the
final leg of delivering connectivity from a
communications provider to a customer. The
phrase is therefore often used by the
telecommunications

and
cable television

industries. The actual distance of this leg
may be considerably more than a
mile
,
especially in rural areas.

What is last mile operation ?


It is typically seen as an expensive challenge
because "fanning out" wires and cables is a
considerable physical undertaking. Because
the last mile of a network to the user is also
the first mile from the user to the world, the
term "
first mile
" is sometimes used.

Last mile


To solve the problem of providing enhanced
services over the last mile, some firms have
been mixing networks for decades. One
example is
Fixed Wireless Access
, where a
wireless network is used instead of wires to
connect a stationary
terminal

to the
wireline

network.

What is Wimax ?


WiMAX is a wireless digital communications
system, also known as IEEE 802.16, that is
intended for wireless "metropolitan area
networks". WiMAX can provide broadband
wireless access (BWA) up to 30 miles (50 km) for
fixed stations, and 3
-

10 miles (5
-

15 km) for
mobile stations. In contrast, the WiFi/802.11
wireless local area network standard is limited in
most cases to only 100
-

300 feet (30
-

100m).



Integration with an IP
-
based network

Integration with an IP
-
based network


The WiMAX Forum has proposed an
architecture that defines how a WiMAX
network can be connected with an IP based
core network, which is typically chosen by
operators that serve as Internet Service
Providers (ISP); Nevertheless the WiMAX BS
provide seamless integration capabilities with
other types of architectures as with packet
switched Mobile Networks.

Integration with an IP
-
based network


The WiMAX forum proposal defines a number of components, plus
some of the interconnections (or reference points) between these,
labeled R1 to R5 and R8:


SS/MS: the Subscriber Station/Mobile Station


ASN: the Access Service Network
[19]


BS: Base station, part of the ASN


ASN
-
GW: the ASN Gateway, part of the ASN


CSN: the Connectivity Service Network


HA: Home Agent, part of the CSN


AAA:
Authentication, Authorization and Accounting

Server, part of
the CSN


NAP: a Network Access Provider


NSP: a Network Service Provider


Integration with an IP
-
based network


It is important to note that the functional
architecture can be designed into various
hardware configurations rather than fixed
configurations. For example, the architecture is
flexible enough to allow remote/mobile stations
of varying scale and functionality and Base
Stations of varying size
-

e.g. femto, pico, and
mini BS as well as macros.

WiMAX installation


There are numerous devices on the market that
provide connectivity to a WiMAX network. These are
known as the "
subscriber unit
" (SU).


There is an increasing focus on portable units. This
includes handsets (similar to cellular
smartphones
);
PC peripherals (PC Cards or USB dongles); and
embedded devices in laptops, which are now
available for Wi
-
Fi services.

WiMAX installation


In addition, there is much emphasis by
operators on consumer electronics devices
such as Gaming consoles, MP3 players and
similar devices. It is notable that WiMAX is
more similar to Wi
-
Fi than to
3G

cellular
technologies.


WiMAX installation


The WiMAX Forum website provides a list of
certified devices. However, this is not a
complete list of devices available as certified
modules are embedded into laptops, MIDs
(
Mobile Internet devices
), and other private
labeled devices.

WiMAX installation
: Gateways


WiMAX gateway devices are available as
both indoor and outdoor versions from
several manufacturers. Many of the WiMAX
gateways that are offered by manufactures
such as
Airspan
,
ZyXEL
,
Huawei
,
Motorola
,
and
Greenpacket

are stand
-
alone self
-
install
indoor units. Such devices typically sit near
the customer's window with the best WiMAX
signal, and provide:

WiMAX installation
: Gateways


An integrated Wi
-
Fi access point to provide the
WiMAX Internet connectivity to multiple
devices throughout the home or business.


Ethernet ports should you wish to connect
directly to your computer or
DVR

instead.


One or two
PSTN

telephone jacks to connect
your land
-
line phone and take advantage of
VoIP.


WiMAX installation
: Gateways


Indoor gateways are convenient, but radio losses mean
that the subscriber may need to be significantly closer to
the WiMAX base station than with professionally
-
installed external units.


Outdoor units are roughly the size of a laptop PC, and
their installation is comparable to the installation of a
residential
satellite dish
. A higher
-
gain directional
outdoor unit will generally result in greatly increased
range and throughput but with the obvious loss of
practical mobility of the unit.

WiMAX installation
: Dongles


There are a variety of USB dongles on the
market which provide connectivity to a
WiMAX network. Generally these devices are
connected to a notebook or netbook whilst
on the go. Dongles typically have
omnidirectional antennae which are of lower
-
gain compared to other devices, as such
these devices are best used in areas of good
coverage.

WiMAX installation
: Mobile phones


HTC announced the first WiMAX enabled
mobile phone, the
Max 4G
, on Nov 12th
2008.
[12]

The device was only available to
certain markets in Russia on the Yota
network.

WiMAX installation
: Mobile phones


HTC and
Sprint Nextel

released the second WiMAX
enabled mobile phone, the
EVO 4G
, March 23, 2010
at the CTIA conference in Las Vegas. The device,
made available on June 4, 2010,
[13]

is capable of
both EV
-
DO(3G) and WiMAX(4G) as well as
simultaneous data & voice sessions. The device also
has a front
-
facing camera enabling the use of video
conversations.
[14]

A number of WiMAX Mobiles are
expected to hit the US market in 2011.

WiMAX installation
: MAC (data link)
layer


The WiMAX MAC uses a
scheduling algorithm

for which the subscriber station needs to
compete only once for initial entry into the
network. After network entry is allowed, the
subscriber station is allocated an access slot
by the base station. The time slot can enlarge
and contract, but remains assigned to the
subscriber station, which means that other
subscribers cannot use it.

WiMAX installation
: MAC (data link)
layer


In addition to being stable under overload and
over
-
subscription, the scheduling algorithm can
also be more
bandwidth

efficient. The
scheduling algorithm also allows the base
station to control
Quality of service

(QoS)
parameters by balancing the time
-
slot
assignments among the application needs of
the subscriber station.

WiMAX Performance


As a standard intended to satisfy needs of
next
-
generation data networks (
4G
), WiMAX
is distinguished by its dynamic burst
algorithm modulation adaptive to the physical
environment the RF signal travels through.
Modulation is chosen to be more spectrally
efficient (more bits per
OFDM
/
SOFDMA

symbol).

WiMAX Performance


That is, when the bursts have a high
signal
strength

and a high
carrier to noise

plus
interference ratio (CINR), they can be more
easily decoded using
digital signal
processing

(DSP).

WiMAX Performance


In contrast, operating in less favorable
environments for RF communication, the
system automatically steps down to a more
robust mode (burst profile) which means fewer
bits per OFDM/SOFDMA symbol; with the
advantage that power per bit is higher and
therefore simpler accurate signal processing
can be performed.

WiMAX vs. LTE


The more recent Long Term Evolution (LTE)
standard is a similar term describing a parallel
technology to WiMAX that is being developed
by vendors and carriers as a counterpoint to
WiMAX.


An example of Wireless competition



Korea launched Wimax at 2nd quarter of 2006
and then launched HSPA one quarter after
launched Wimax. At the end of 2008 there were
8.4 million HSPA subscribers and 350,000
Wimax subscribers in Korea. Almost all of
HSPA subscribers come from 2G and 3G users
who have been tempted to upgrade to new
devices by high subsidies, whereas Wimax
subscribers almost all are newcomers.

An example of wireless competition


Deployment of Wimax is still limited (spotted),
whereas there are well over 100 countries
where HSPA networks are deployed, and even
where there is no HSPA coverage there is
backward compatibility (using HSPA devices)
to pre
-
existing networks (GSM and WCDMA)
with a roaming infrastructure already in place

WiMAX statistics


As of October 2010, the WiMAX Forum
claims there are over 592 WiMAX (fixed and
mobile) networks deployed in over 148
countries.


Yota

is the largest WiMAX network operator
in the world, but has announced that it will
move new network deployments to LTE and,
subsequently, change its existing networks
as well.

What is HSPA ?


High Speed Packet Access (HSPA)
is an
amalgamation of two
mobile telephony

protocols
, High Speed Downlink Packet Access
(
HSDPA
) and High Speed Uplink Packet
Access (
HSUPA
), that extends and improves
the performance of existing
WCDMA

protocols.
A further standard,
Evolved HSPA

(also known
as HSPA+), was released late in 2008 with
subsequent adoption worldwide beginning in
2010.

WiMAX competitors


Within the marketplace, WiMAX's main
competition comes from existing, widely
deployed wireless systems such as
UMTS
,
CDMA2000
, existing Wi
-
Fi and mesh
networking.

WiMAX competitors

Speed vs. Mobility of wireless systems:
Wi
-
Fi
,
HSPA
,
UMTS
,
GSM


The future of wireless networks


In the future, competition will be from the
evolution of the major cellular standards to so
-
called
4G
, high
-
bandwidth, low
-
latency, all
-
IP
networks with voice services built on top. The
worldwide move to 4G for GSM/UMTS and
AMPS
/
TIA

(including CDMA2000) is the
3GPP Long Term Evolution

effort.