Difficult to compare with 3GYes, WiMAX is a promising technology and appears to be a good broadband solution, but its real benefit lies in offering fixed wireless rather than truly mobile applications. However, as equipment for the mobile variant of WiMAX (802.16e) is not yet available, it is very difficult to compare WiMax with 3G which includes high speed packet access (HSPA).
But from what we do know, 3G/HSPA has several clear advantages vis-à-vis mobile WiMAX in terms of backward compatibility, standardisation, use of licensed spectrum and availability of infrastructure and terminals giving it an edge over WiMAX in terms of large scale economies leading to better affordability, availability, scalability and overall ruggedness of the 3G/HSPA standard. Further, the pace of adoption of HSPA has been remarkable. HSPA is already commercially available in Africa, America, Asia, Australia, the European Union and the Middle East. There is thus already a large ecosystem of global suppliers of components, subsystems, equipment and network design and implementation services in place for 3G/HSPA.
WiMAX on the other hand faces a number of challenges. Mobile WiMAX standards are still under evaluation. The capex for deploying WiMAX is upto 5-10 times higher than HSDPA because the size of mobile WiMax cells is upto 16 times smaller than the cells in an HSPA system, which would necessitate a larger number of base stations to cover the same geography.
Further, the prices of mobile WiMAX handsets as and when available, will be significantly higher than the cellular terminals, which are being developed in much higher volumes and offered at increasingly lower costs. Also WiMax has fragmented frequency bands. In Europe and the United States, WiMAX operates in 3.5GHz and 5.8GHz while in Asia Pacific it operates in 2.3, 2.5, 3.33 and 5.8GHz. This makes global or even pan-regional roaming rather difficult. Users visiting different countries will have to either hope that the visited country uses the same band or have their devices equipped with multiple modes to enable connectivity to other WiMAX based broadband networks. WiMAX systems also have a lower capacity for voice vis-à-vis 3G/HSPA networks, which will limit the potential market size that WiMAX can cater to.
In light of the above, it would be evident that the 3G/HSPA is far more capable of providing mobile broadband service to the market. HSPA will allow the mobile operators to exploit the full potential of 3G by offering mobile broadband services at competitive prices. However, WiMax will find its own role in several broadband fixed wireless access and in some limited mobility applications. Thus, while WiMAX will no doubt have a role in India’s wireless future, it is unlikely to pose any serious challenge to the large scale ubiquitous mobile services offered under 3G/HSPA.
As regards, the inclusion of WiMax in the IMT-2000 family, before any such proposal is considered, it must be preceded by extensive studies and fullest review of coordination and interference aspects along the lines prescribed by ITU. This is because technical sharing studies carried out in several countries on WIMAX have indicated that there is an impairment of the band by harmful interference. In this context, it may be noted that WiMAX is based on OFDMA (Orthogonal Frequency Division Multiple Access) technology that is more prone to inter-channel interference. It is therefore imperative that this aspect be fully studied and addressed before WiMAX is considered for inclusion in the IMT 2000 family.
The Indian government on its part is also independently studying the reports of various countries/evaluation groups and will also be providing its inputs to ITU on the issue of inclusion of WiMAX in the IMT 2000 family.
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