What is wireless landscap?

Answer 1

While a lot of attention has been placed on the growing standards war for next generation wireless network standards between LTE and WiMAX - for instance see here and here - a number of interesting developments have been made regarding the Chinese developed outsider TD-LTE.

TD-LTE is a standard for wireless mobile networks and 4G candidate which has been developed by China Mobile, building upon the TD-SCDMA 3G standard. The TD-LTE stems from China's indigenous innovation policy which seeks to reduce China's reliance upon foreign IPR by supporting the use of domestic alternatives. (Don't miss the upcoming Talkstandards open forum for further discussion on China's standards policy).

The TD-LTE standard has been submitted, along with 5 other competing standards including LTE and WiMAX, to the International Telecommunications Union (ITU) for consideration for inclusion in the 4G family and Zhao Houlin, ITU deputy secretary-general, has commented that:

"I am confident about the market application of TD-LTE around the world, and it has a 70 percent possibility to be chosen as the 4G standard."

TD-LTE is interesting in that it bridges the gap between LTE and WiMAX. While based upon the same 3GPP package as LTE, it differs in the method of "duplex", which is how devices communicate in two directions - receiving and transiting data simultaneously. While the LTE supported in Europe and the US uses Frequency-Division Duplexing (FDD) TD-LTE uses an alternative method called Time-Division Duplexing (TDD) which is also the same approach used by the IEEE 802.16 standard upon which WiMAX is based. Furthermore, TD-LTE utilizes cheaper and less congested radio spectrum compared to LTE.

Simply speaking FDD uses paired spectrum with two channels, designating one each for upload and download, while TDD uses unpaired spectrum channels that combines upload and download and distributes the resources based on real-time demand. As such, FDD is best utilized by voice calling in which both upload and download are symmetrical, while TDD is advantageous for use with data traffic, which is asymmetric.

The result of this is that due to the similarities between LTE and TD-LTE, both technologies can be supported by a single chip-set while the towers designed for WiMAX can be upgraded for use with TD-LTE at relatively low cost. So while there is considerable interoperability between the LTE and WiMAX standards, TD-LTE indirectly circumvents the present divide.

However aside from TD-LTE merely ending up a setting on multi-mode devices, the standard is expected to see deployment outside of China in the near future. It has beenannounced that Qualcomm has won significant slabs of unpaired spectrum in India for US $1.07 billion (~ € 874 million), in which the company plans to launch a TD-LTE compliant network. Similarly, despite China remaining in the early stages of a full scale rollout of 3G, China Mobile appears egger to "leapfrog" to 4G due to the weakness of the Chinese proprietary TD-SCDMA compared to W-CDMA and CDMA2000.

Deployment of the technology in both China and India, which together make up 40% of the world population, will surely be a great boost for the standard. The changing global economy is bringing an increasing importance to the mobile markets of China and India, which represent both the world's largest uninterrupted mobile market and the world's fastest growing mobile market respectively. Moreover, as the standard can operate on the same chip set as LTE, there will be no lack of compliant handsets which will favor a wide uptake.

If the not so successful TD-SCDMA in any way acts as an indicator for the success of TD-LTE, outlooks are bleak. But the Chinese standard is bound to gain a strong foothold in the developing world, while LTE is deployed in Europe and the US. There is a significant compatibility between the two and TD-LTE's edge lies in the lower cost TDD spectrum. It is this fact that raises the probability of China succeeding to export a mature ICT standard from the developing to the West.