wimax and non standard solutions
TRANSCRIPT
Multimedia Training Kit
WiMAX and Non-Standard Solutions
Developed by:
Ermanno Pietrosemoli, EsLaREd
Creative Commons License: Attribution
Non-Commercial Share-Alike 3.0
Unit 14
Objectives
Describe WiMAX technology, its motivation and compare it with WiFI.
Review some non-standard commercial solutions that have been used in the implementation of medium and long range wireless community networks.
Agenda
Introduction
Standards for wireless networks
WiMAX
Non standard solutions
Alvarion
Canopy
MIKROTIK
WANWide Area Network
PANPersonal Area NetworkLANLocal Area NetworkMANMetropolitan Area Network802.15802.11802.16d802.20802.16eHiperPANHiperLANHiperMANHiperACCESSIMT-2000802.22Standards for wireless networks
IEEE
UIT
ETSI
Introduction
2000: Public auction in Venezuela of the 3400-3500 MHz frequency band to provide voice and data services
Unsuccessful for the following reasons:
Absence of standards
Need for line-of-sight between the base station and each client.
Both factors have a strong impact on the cost of deployment and motivated the establishment of a standard for networks of medium and long range, preferably removing the line of sight requirement. These features are met by the IEEE 802.16 standard, on which WiMAX is based .
IEEE 802.16
Born as a standard for wireless metropolitan networks (high speed, reaching tens of km) for frequencies between 11 and 66 GHz.
Point to Point or Point-to-Multipoint.
First amendment to extend the range of operation at frequencies below 11 GHz and allowing OFDM, which paves the way for non line of sight operation.
Burst adaptive Profile
Burst Profile
Modulation and FEC allocated dynamically according to the link conditions: Exchange of capacity for robustness
The capabilities of the SS are known at the time of initialisation
Duplexing schemas
TDD
The upstream and downstream links share the same RF channel
Dynamic asymmetry. Efficient use of the spectrum, but requires guard time. Optimized for packets.
SS does not transmit and receive simultaneously, which allows costs reduction. Requires more power.
FDD
Static asymmetry. Requirement of guard band.
In Half Duplex cost is low
IEEE 802.16
Built in Quality of Service (QoS) to meet the needs of interactive traffic (voice and video)
Takes advantage of multipath by using MIMO
Better spectral efficiency and a wide variety of techniques for using the channel, SC, OFDM, OFDMA, TDD, FDD
Flexibility in managing bandwidth and spectrum, variable and asymmetric channels, licensed or unlicensed bands
802.16 vs 802.11
QoS Multimedia, no contention for channel access (802.11e offers QoS)
Many additional users
Higher transmission rates, up to 75 Mbps in a 20 MHz channel (but 802.11n has even greater transmission rates)
Greater range
Variable bandwidth channels
Better spectral efficiency, ~ 5 bps / Hz
(802.11n has better spectral efficiency)
Two different markets
In countries with limited telecommunications infrastructure, to provide fixed or nomadic access to voice and data using external antennas, possibly in combination with other technologies such as WiFi, PLC or Ethernet.
Based on the d amendment of the 802.16 standard approved in 2004
In countries with good telecommunications infrastructure, mobile access to voice and data
Based on the e amendment of the 802.16 standard approved in 2005
WiMAX :
Wireless Microwave Access
Nonprofit organisation sponsored by several companies to define "profiles" within the standard and ensure interoperability of products.
Interoperability tests performed by two independent laboratories in Spain and South Korea.
Promoting technology in a manner similar to what the WiFi Alliance did for 802.11.
Fixed and mobile WiMAX
The two versions of the standard are incompatible because they use different medium access techniques
Some manufacturers offer devices that implement both versions of the standard
Fixed and Mobile WiMAX are differentiated, although there may be overlap
The mobile solution has a much smaller range, on the order of a few kilometres, while the fixed one, with external antennas can reach tens of kilometers if there is line of sight
WiMax vs WiFi
Wi-Fi was designed for networks with very few clients at close range
It has a lot of limitations when applied outdoors at distances of several miles, due to the problem of the hidden node and the waiting time to receive ACK
Commercial solutions such as Solectek and Lucent use a non standard mechanism, polling, to resolve this limitation
Solectek Antenna,1997
WMM: WiFi Multimedia
Another limitation is that Wi-Fi had no mechanisms to provide QoS.
These mechanisms have been incorporated in 802.11e, which provides 4 categories of priority traffic:
Voice
Video
Best Effort
Low Priority
Scalability and throughput
WiFi uses 20 MHz channels; WiMAX is flexible allowing channels from 1.5 MHz to 20 MHz, with spectral efficiency superior to that of 802.11 a and g, but lower than that of 802.11n
The transmission rate can be different in the up and downlink channels, and for near and far clients
WiBRO
Is a WiMAX variant, first to be commercially installed (South Corea, 2006)
Nowadays is part of the mobile WiMAX standardised profiles
Implements handover at speeds up to 80 km / h.
Video quality and fast transfer of files.
VoIP in small mobile terminals
WiBRO
WiBRO
WiBRO
WiMAX, now a UIT standard
Extension of IMT-2000 to the frequencies between 2,5 GHz and 2,69 GHz
Part of IMT-2000 standards
W-CDMA
CDMA- 2000
TD-SCDMA
OFDMA TDD WMAN
New spectrum adjudication
for WiMAX by UIT
Potential to reach 2700 million peoplehttp://www.dailywireless.org/2007/09/10/luxor-wimaxed/
IEEE 802.22 and Cognitive Radio
Reuse of TV spectrum between 54 and 862 MHz.
Suitable for rural communications due to its greater range.
Maximum power of 1W for fixed devices and 100 mW for mobile.
Non-standard solutions
Alvarion
Motorola Canopy
Mikrotik
Alvarion
Offers a variety of wireless equipment for different applications.
Originally proprietary equipment, but now WiMAX approved.
In Merida, in 2002, a link was installed from a station that collects atmospheric data located at 4765 m altitude, to the Universidad de Los Andes, located at an altitude of 1800 m, and at a distance of 15 km.
A webcam transmits images of Pico Bolivar (5000 m) and other data in real time:
http://www-imk.fzk.de/imk2/mira/Merida/Merida.html
Instruments installed in MARS
Receiver for the 270 GHz signal. Note the quality of the antenna reflector and the use of liquid nitrogen to reduce the receiver's noise temperature. Alejandro Humboldt Station, Pico Espejo, Merida State, Venezuela. http://www.cecalc.ula.ve/redbc/estaciones/estacion_pico_espejo_mars.html
Alvarion DS 5800, Pico Espejo
IDU
ODU
Alvarion 4 motion
Alvarion's WiMAX mobile solution is being deployed in Rosario (Argentina) by ERTACH in the 3,5 GHz band
http://www.dailywireless.org/2007/10/10/
Motorola Canopy
The Canopy line is a flexible solution for both PtMp and PtPt networks
It offers a variety of transmission speeds reaching up to 300 Mps
It works in all bands that do not require license in the United States: 900 MHz; 2,4 GHz; 5,15 GHz; 5,4 GHz; and 5,8 GHz
Motorola Canopy Base Station
Motorola Canopy
26 dBi gain with reflector, 8 dBi without reflector
PoE
UTP cable lighting protection
Being ported to WiMAX
Mikrotik
Sells a linux based proprietary operating system that runs on different platforms, allowing long distance links, with different functionalities depending on the acquired license.
It also offers hardware with preinstalled operating system
Board that accepts up to 3 radios
Canopy Interference Immunity
Optimised for rejecting interference
The radios are designed to work with a mere 3 dB C/I
Not affected by self-interference, thanks to the synchronisation between different units using a GPS receiver
Compare with other systems that require between 8 and 25 dB C/I
Conclusions
The IEEE 802.16 Standard is the basis of WiMAX
There are two versions of WiMAX, one for fixed clients, based on IEEE 802.16-2004 (802.16d) and another for mobile clients, based on IEEE 802.16-2005 (802.16e)
While WiMAX has many technical advantages with respect to WiFi, the latter continues progressing and filling many of the gaps in the original standard and, at the same time, maintaining a significant economic advantage
The five main points that you must remember in this unit can be summarised as:
4. WiFi is more amenable to organisations that want to install their own infrastructure, while WiMAX is usually installed by a big operator
5. Although there are commercial solutions for wireless networks that may be the most suitable in some cases, it is generally preferable to use standard solutions with better guarantees of continuing support
Conclusions
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