The WiMAX system was designed to popularize broadband access the way cell phones have done to our telephone communication system. WiMAX may replace the old form of broadband access through landlines, DSL and cable in future.
The WiMAX system can be considered as an efficient alternative to Wi-Fi, where the un-avoidable limitation was the distance of coverage. WiMAX solves this problem by using higher frequency range to deliver more data to a larger distance.
How WiMAX Works?
WiMAX, just like Wi-Fi uses radio waves to transfer data. The important difference is that WiMAX uses two spectrums of frequencies to provide two kinds of wireless broadband access services. (Mobile WiMAX & Fixed WiMAX)
The WiMAX system has two parts; one is the WiMAX tower (similar to a cell phone tower) and a receiver. The receiver can be of two types depending on the device. It can be an embedded device just like our wi-fi receivers or it can be advanced hardware equipment with dedicated antennae.
The WiMAX tower connects to internet through regular mediums of connectivity like fibre optic cable or T1 lines. It can also connect with other WiMAX towers using radio link.
This additional line-of-sight connectivity is the biggest advantage of WiMAX. Technically, this is called the backhaul system. Thus by installing multiple towers, WiMAX can easily provide broadband access to large number of people.
Mobile WiMAX & Fixed WiMAX Operation
WiMAX delivers broadband access in two ways depending on the operational frequencies.
Low Frequency Operation - Mobile WiMAX
In this form, WiMAX tower works more like an efficient & powerful wi-fi access point. The frequency range of operation is 2GHz - 11GHz, almost similar to wi-fi frequencies.
In this mode of operation, the data transfer occurs between WiMAX tower and the internal mobile receivers. As the frequency of operation is low, there is a limitation in area of coverage.
According to theory, this type of WiMAX can only deliver up to 6-7 KMs.
The same effect can be analogized to cell phone tower system. That is the same reason, why we need more number of towers for wide area coverage.
High Frequency Operation - Fixed WiMAX
In this form, the receiver requires dedicated antennae properly installed in the line-of-sight of WiMAX tower. These types of connections are stronger and stable as it uses 66GHz frequency spectrum to carry more data.
This mode of operation can deliver broadband services to about 50KM radius.
WiMAX vs. Wi-Fi
Even though both WiMAX and Wi-Fi works on radio waves, there are differences in their operations and functionalities.
Range:
WiMAX is a long distance system capable of providing high-speed broadband access to several KMs. While Wi-Fi is short-range system that can only provide broadband access to several hundred feet.
Data Rate:
WiMAX can deliver data rate of up to 70Mbps, while that of Wi-Fi G is 54Mbps. The next version Wi-Fi (Wi-Fi n) can deliver 108Mbps speed; however, it can only provide this to a short distance of few hundred feet.
Scalability:
WiMAX is highly scalable. By setting up multiple towers in the line-of-sight, WiMAX can cover a large area. Each of these towers does not necessarily need separate internet connectivity. On other hand, each wi-fi access point would need separate internet input to scale it.
Local Networks:
As WiMAX is an ISP based system, you cannot use it for your own private network. While Wi-Fi can still work for private networks even if you do not need broadband.
Spectrum Licensing:
The high frequency operation mode of WiMAX requires spectrum licensing (to be owned by ISPs). On other hand, wi-fi implementation does not require such a license.
Advantages of WiMAX
Large Area of Coverage: As WiMAX can deliver high-speed internet to large distance, it is very well suited to provide broadband access to remote areas of the world.
Scalability: As earlier mentioned, by using backhaul feature of WiMAX, you can set up large number of WiMAX towers in matter of days as opposed to wiring that requires proper planning and heavy labor.
In Built QoS: Quality of Service mechanisms in WiMAX allows mission-critical services to run smoothly even if there is lack of resources. This way, mission critical services are allowed to run at full priority when everything is busy.
Multi-User Connectivity: A single WiMAX tower can connect to 100 client receivers. These clients can of different modes of operation.
Disadvantages of WiMAX
Specialized Equipment Required: For utilizing full functionality of WiMAX, you need specialized hardware with dedicated antennae.
Limited Date Rate: When compared to other modes of broadband connectivity, for example, fibre optic cables and satellite internet, WiMAX is still slow.
Bandwidth Shared Among Users: WiMAX’s another drawback is that it distributes the bandwidth among users. This means, you will experience slow down when there are more uses in the base.
Speed Decrease over Large Distance: Because of bit rate errors happening at large distance, WiMAX system is forced to use lower bit rates at these distances. This means less data transfer rate.
Interference May Affect Connectivity: As the WiMAX uses radio waves, it is susceptible to interference caused by other equipments.
Rain can affect Connectivity: As fixed WiMAX requires line-of-sight radio link, heavy rain can disrupt the entire link.
Conclusion
As WiMAX delivers high-speed internet through wireless medium, the cost of implementing broadband access to remote parts of world are very low. Because of the same reason, we believe WiMAX have huge potential to become the world’s popular broadband access method in near future.
Reference:
WiMAX Forum
HowStuffWorks.Com
Wikipedia