Various reports and discussions have started trying to compare WiMAX and HSPA/LTE and also justifying why WiMAX is better or vice versa. so will WiMAX compete with 3G+? To answer this problem lets go back to the beginning of 3G.
NTT DoComo launched the worlds first 3G system which it called as FOMA. Infact before FOMA it already had i-Mode available which was a revolutionary technology of its time. So instead of being so great and revolutionary, why was it not adopted by everyone. The answer is that it was a closed technology and not an open standard.
WiMAX is comparatively an open standard. Its Specifications are not available freely as is 3G. This gives 3G a definite advantage over WiMAX. Also 3G+ (which includes HSPA, HSPA+, LTE, MIMO, etc) has evolved from 3G which has in turn evolved from GSM. There is an inbuilt facility to move between 3G/GSM and perform Handovers, etc. This would be missing in WiMAX.
You may argue that once IMS is there, these problems wont be big as IMS would allow these handovers to take place. IMS is access agnostic. The problem is that it will take time for IMS to be adopted and for it to be completely functional. When this happens, by that time LTE would already be available. LTE uses the same Radio Technology as WiMAX and since it has evolved ffrom 3G/GSM, it would definitely be preferrred over WiMAX.
There was an article in Financial Express last week comparing WiMAX and 3G. Some important points from that:
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.
Arthur D. Little and Altran Telecoms & Media have also produced a report for GSM Association comparing HSPA and Mobile WiMax for Mobile Broadband Wireless Access (MBWA). According to them:
HSPA is likely to account for the majority of investment in global mobile broadband networks over the next five years, finds a new study by Arthur D. Little. By comparison mobile WiMax will be a niche technology within the overall
global mobile broadband wireless access market, likely to account for at most 15% of this network equipment market and perhaps 10% of mobile broadband wireless subscribers by 2011-2012.
HSDPA (including HSUPA and HSPA+) is taking the lead as it is a natural migration path for a large number of GSM and UMTS operators already operating commercial networks in 3G spectrum. This will give rise to significant economies
of scale on handsets and user devices and a large ecosystem of global suppliers of components, subsystems, equipment and network design and implementation services. Hence this is the least risky and best understood route to offering broadband mobile services which can offer speeds comparable to first generation fixed DSL services.
According to a report in Broadband Wireless Exchange Magazine:
The results of Arthur D. Little's modeling work shows that WiMax systems are expected to achieve significantly greater theoretical peak data transfer rates when deployed than today's commercial HSPA networks deliver now, such as theoretical speeds of e.g. 16.8 Mbps in urban areas vs 2-3 Mbps for HSPA. However, the coverage a WiMax base station can achieve, is substantially lower than HSPA, hence HSPA operators will be able to deploy a smaller number of base stations and sites to cover the same geography. Indications are that radio access network capex for current WiMax technology can significantly exceed HSDPA capex.
Another consequence of this characteristic of these two technologies is that an HSPA operator will be able to match its growing investment more clearly to the development of demand than mobile WiMax operators who will have to install more cell sites at the beginning to ensure coverage.
Arthur D. Little acknowledges that in the longer term, well into the second decade of this century, mobile broadband wireless systems will be characterized by technologies such as OFDMA and MIMO. Development of these technologies is being pursued by the 3G/HSPA ecosystem within the framework of 3G LTE as well as by WiMax. The long term future relative roles of 3G LTE and mobile WiMax, both of which face major development hurdles before they achieve the full promise of new, so-called 4G systems, is uncertain and will be influenced by continuing expected shifts in the priorities and competitive alignments of major players in the wireless industry which has undergone a number of consolidations in recent months.
In contrast to many other reports on HSPA, mobile WiMax and other broadband wireless technologies, the Arthur D. Little study highlights and assesses all the factors - strategic, competitive, commercial, regulatory and political as well as technological that influence operators' choices of wireless network technology.
Evidence for the potential complementary nature of HSPA and WiMax can be seen in the increased interest in multi-mode user devices and roaming capabilities across the technologies. This development, which reflects the widespread anticipation of the central role of OFDMA and other technologies involved in WiMax and 3G LTE in all eventual future broadband wireless networks, is a welcome change from the provocative and misleading headlines that have appeared over the past two years which imply that mobile WiMax threatens the viability of today's HSPA and related technologies
With Intel promising WiMAX chips on all its laptops in future, only time will tell how far WiMAX will and if this comparison holds true.
