WiMAX technology

WiMAX is similar to Wi-Fi technology. both create hot-spots. Wi-Fi can cover several hundred meters while WiMAX covers a range of 40-50 km. It provides a wireless alternative to cable, DSL, and also have broadband access.

WiMAX can be used as a complementary technology to connect 802.11 hotspots to the internet. Mobile-Fi is the mobile version of WiMAX. It is used to provide internet access to mobile users at data rates even higher than available in today broadband links.

A wireless broadband solution that offers various features of WiMAX with a lot of flexibility in terms of potential service offering is WiMAX.

A Mobile-Fi user can enjoy broadband internet access even while traveling in a moving car or train. WiMAX could potentially be deployed in a variety of spectrum bands like in different range 2.3 GHz, 2.5 GHz, 3.5 GHz, and 5.8 GHz.

A WiMAX architecture consists of two major parts: Main part is to be (i) A WiMAX base station (ii) A WiMAX receiver.

Following Major principles :

  • Spectrum is − able to be deployed in both licensed and unlicensed spectra.
  • Topology − supports different Radio Access Network topology.
  • IP connectivity network − supports a mix of IPv4 and IPv6 network interconnects in application and clients servers.
  • Mobility management − It is a possibility to extend the fixed access to broadband multimedia services delivery.
  • Interworking − WiMAX support independent RAN architecture to enable seamless integration and interworking with 3GPP2, 3GPP, and  WiFi networks.
A wireless broadband solution that offers various features with a lot of flexibility in terms of potential service offering is WiMAX.
  • WiMAX support multipath.
  • WiMAX must be provided up to 50 km of service area range.
  • WiMAX uses OFDM technology.
  • WiMAX support TDD and FDD.
  • WiMAX offer modulation and error correction.
  • Adaptive modulation enables a WiMAX system to optimize the throughput based on the when propagation conditions apply.
  • Very scalable bandwidth and high-speed data rate.
  • WiMAX benefits are that it is flexible and dynamic per-user resource allocation.
  • Support for advanced antenna techniques.
  • Support for mobility.
  • Portable internet usage.
  • Quality of service support.
  • It is IP based architecture.
  • WiMAX is always best connected.
  • The most important application of WiMAX technology offered by  is business, Multiplayer interactive gaming, backhaul, consumer connectivity, large area coverage access
WiMAX standard :

These standards were issued by IEEE 802.16 into the subgroup of 802.16a / REV d / e standard that originally covered the Wireless local loop (WLL) technologies with radio spectrum from 10 to 66 GHz. Recently were extended below 10 GHz.

In the year of January 2003, the approved IEEE 802.16a as an amendment to IEEE  802.16 defining as a line of sight capability (LOC).

In the year of 2004, the IEEE 802.16 Revd was introduced to support indoor customer premises equipment through additional radio capabilities like antenna beamforming and OFDM sub channeling.

WiMAX supported to different frequency band considered as a different range.

In the year of 2005, an IEEE 802.16e variant was developed for supporting total mobility.

Following are the details of various IEEE 802.16 standard related to WiMAX.

1. 802.16
  • Spectrum - 10-66 GHz
  • Configuration  - Line of sight
  • Mobility - Fixed
  • Channel bandwidth - 20,25 MHz
  • Typical cell radius - 1-3 miles
  • Modulation - QPSK-16 QAM 64 QAM
  • Completion  - December 2001
2. 802.16a
  • Spectrum - 2-11 GHz
  • Configuration  - Non-Line of sight
  • Mobility - Fixed
  • Channel bandwidth - Selectable, 1.25-20 MHz
  • Typical cell radius - 3-5 miles
  • Modulation - total 256 subscriber, OFDM using QPSK, 16 QAM, 64 QAM, 256-QAM
  • Completion - January 2003
3. 802.16e
  • Spectrum - <6 GHz
  • Configuration  - Non-Line of sight
  • Mobility - Fixed
  • Channel bandwidth - 5 MHz planned
  • Typical cell radius - 1-3 miles
  • Modulation - 256 subscriber, OFDM using QPSK16, QAM, 64 QAM, 256-QAM
  • Completion - 2nd half of 2005
WiMAX architecture :

A WiMAX system consists of two major parts: Main part is to be (i) A WiMAX base station (ii) A WiMAX receiver.

Let us take a look at the WiMAX architecture to shown in the figure.

A WiMAX base station :

WiMAX base station is very similar to accessing a wireless access point in a Wi-Fi network, but the coverage is greater than to other networks.

In general WiMAX base station can provide a very large area up to a radius of 6 miles. A WiMAX base station consists of indoor electronics and as we know that WiMAX tower similar look like to a cell phone tower.

Each base station provides wireless coverage over an area called a cell. The WiMAX base station also uses a multiple antennas point in a different direction. This area covered by one antenna signal is called a sector.

The uplink and downlink channel are shared among the many subscriber stations in a given sector. WiMAX can also have support bursty data and high-quality telephone and high volume multimedia.

The uplink and downlink channels are divided into slots of equal size. A WiMAX frame takes multiple slots. The different frame takes a different number of slots. The downlink channel easy to subdivide into the connection as only the base station sends on that channel.

A WiMAX receiver : 

A WiMAX receiver may have a separate antenna or could be a stand-alone box or a PCMCIA  card present in your laptop or any other device. It is called Customer premise equipment (CPE).

In most of the cases, a simple plug and play terminal, similar to a DSL modem provides connectivity as shown in the figure.

For customer located several kilometers from the WiMAX base station, a self-install outdoor. The antenna may be required to improve transmission quality. 

For customer requesting a voice in addition to broadband services, specific CPE will allow the connection of standard or VoIP phones.

                   WiMAX architecture
Application of WiMAX :
  • It is a wireless alternative to many existing wired and late miles coverage deployments such as cable modem, digital subscriber line, T and E-carrier system and optical carrier technologies.
  • The most important application offered by WiMAX technology is business, Multiplayer interactive gaming, backhaul, consumer connectivity, large area coverage access.
  • Using WiMAX technology it can offer broadband wireless access at data rates of multiple Mbit/second to the end user and also within a range of several kilometers. So in this technology, the same radio technology will also offer high-speed data services to all the nomadic terminal like laptops. PDAs, and several other devices. 
  • IEEE 802.16 -Fixed users.
  • IEEE 802.16e - portable user.
  • Backhaul side - Point to point antenna is used to connect base station located across a long distance.
  • Last mile side - Residential and business subscriber are connected to the base station using point to multi-point antennas.
  • Large area coverage access side - WiMAX also offer broadband connectivity in larger areas.
Wi-Fi and WiMAX offer complementary solutions with Wi-Fi being suitable for short range and WiMAX being suitable for long-range outdoor connection.