Thursday, June 7, 2007

The Competition between WiMAX & 3G and WiMAX Technology Development Trend..

As the fourth generation network, WiMAX system is expected to provide fixed wireless alternative to conventional DSL and Cable Internet.

The competition between WiMAX and 3G:

Before the December of 2005, WiMAX and 3G played their own roles. WiMAX focused on fixed wireless broadband, while 3G was planned to take place of 2G (GSM) mobile communicaiton. However after that, mobile communication of WiMAX standard: IEEE 802.16e came out which made the positions of WiMAX and 3G overlapping. Mobile WiMAX will firstly be used in laptops. Then the size and power will be further reduced in which way it can be used in PDA and more small size portable devices. Especially Mokia has announced that it will release WiMAX mobile phone in 2008 which shows that it is quite possible that Mobile WiMAX will be a new generation mobile communication, not only 3G in consideration.
At the same time, 3G is also trying to enhance its techniques to consolidate its domain. For example, 3G added HSDPA, HSUPA, etc. This increases the transmission speed in 3G data service and it encourages to use HSDPA in mobile devices other than mobile phones. Now there has already been HSDPA interface card for laptops. There is even built-in HSDPA when the devices are made. From this point of view, the competition between WiMAX and 3G has been quite obvious. Then which one will win the game?
As mentioned above, no matter it is WiMAX or 3G, the purpose and used techniques are identical. There is not much difference between them. In order to accelerate transmission, OFDM modulation must be used and MIMO technique must be used for sure. And the HARQ error control mechanism must be used to increase the spectrum efficience.
Except for the same improvement techniques, the implementation tempo between WiMAX and 3G is different. In all IP type and OFDM techniques, WiMAX is in front. Till now 3G still cannot realize all IP and it still has not implemented OFDM technique. As for MIMO and HARQ, 3G is in leading place. While for these two techniques, WiMAX has already included them at the end of 2005. So currently for pure ideal technology standard, WiMAX is superior to 3G.
However, the above is all the comparison of existing facts. The competition on technique has extended to the future promise. 3G field has already had many development plans, including HSDPA, HSPA+, HSOPA, 3GPP LTE, etc. In these future plans, OFDM technique is also introduced and the all IP architecture will also be used. While for WiMAX, after the completion of IEEE 802.16e, there is not very clear further technology plan.
But in 2007, WiMAX will have new behaviors which are mainly the proposals of .16j and .16m. IEEE 802.16j is the standard of Relay Station for Mobile WiMAX. The other one is a proposal for ITU-R. ITU-R is making standards taking the place of IMT-2000 and IMT-Advanced which belongs to the 4th generation mobile communication standard. WiMAX Forum expects that WiMAX techniques can appear in the new standard and at the same time make sure the copatibility of Mobile WiMAX and 4G new standard.
For IEEE 802.16j, the companies of Nortel, Fujitsu and Taiwan give a lot of contributions in the working group.

No comments: