Wednesday 24 October 2007

WiMAX is now an official 3G standard (Was it not 4G?)

Last Thursday evening, the UN agency ITU in Geneva officially admitted WiMax into the IMT-2000 family, which includes the dominant 3G technologies CDMA-2000, W-CDMA and TD-SCDMA. This is the first new addition since MT-2000 was approved in 1999.
"To have WiMax approved as an IMT-2000 technology is a huge win for the WiMax Forum," said Ron Resnick, president of the WiMax Forum, the industry group that certifies interoperability of products using the technology.
In addition to a significant gain in credibility for mobile WiMAX, the main impact of the ITU decision concerns the European market where one of the main barriers for mobile WiMAX adoption was the lack of spectrum availability in the 2.5GHz band. In Europe, it was initially decided that the 2.5-2.690GHz bands would be considered as being IMT-2000 extension bands, or more simply, UMTS/HSPA bands. Of course

WiMAX backers considered this to be unfair and adopted two strategies in order to address this situation:

Theoretically, as a member of the IMT-2000 family of technologies, mobile WiMAX can be deployed by mobile operators using their current 3G spectrum. However, there is almost no chance to see existing mobile operators deploying 16e in their 3G spectrum. There are two key reasons for this:

NOTE: What the standards body actually voted to support was OFDMA (Orthogonal Frequency-Division Multiplexing), which forms the basis of WiMax today but is also set to power future technologies, including LTE (Long-Term Evolution), a system now under development as the next step in the GSM migration path. Commercial LTE deployment is expected in 2009 or 2010.
What this means is technically, ITU didn't accept WiMAX (802.16d/802.16e) per say as 3G standard. What they have done is, accepted "IMT-2000 OFDMA TDD WMAN specification" as 3G standard which in normal terms reffered as 802.16. Put another way, the ITU didn't accept WiMAX, It accepted WMAN. As per the definition of WiMAX forum "WiMAX based upon the harmonized IEEE 802.16/ETSI HiperMAN standard". One more point, ITU approaved 802.16 as a Time Division Duplex (TDD) but not for use in Frequency Division Duplex (FDD). Most of the licensed frequencies are based of FDD. [from Amandeep Singh's post if forum oxford]

The Mobile WiMax system profile was standardized in February 2006. According to several industry sources, the key features of Mobile Wimax are that it uses OFDMA, MIMO, Beam-forming and a number of other recent technology advancements that are labeled as features in 3.9G [LTE]. As a result, Wimax has some key advantages in comparison to other 3Gs, which were set up 7 years ago. It supports several new features necessary for delivering mobile broadband services at vehicular speeds greater than 120 km/hr1 with QoS. Some of Wimax’s key new features and benefits include:
  • Introduces OFDMA, which improves spectrum efficiency (the amount byte transferred on given width of frequency) around two times more than current 3G technologies or Wi-Fi. For the same service, Wimax only need about half of the base station as would for HSPA or EVDO –RevB.
  • Enables a wide range of advanced antenna systems including MIMO, beam-forming, space-time coding and spatial multiplexing. It thus increases the covering range of Wimax; it also can dynamically allocate frequency band (from 1.5 to 20 MHz) based on user’s signal strength, bandwidth requirement. It thus makes better use of available frequency to support more users.
  • Dynamic Power Conservation Management ensures power-efficient operation of battery-operated mobile handheld and portable devices in Sleep and Idle modes. Which may be critical for small devices like cell phones.
  • With 5 millisecond latency between hand-hold device and cellular tower, plus the support of QoS, make Wimax good for high quality VOIP, this wireless data network also competes with 2G and 3G on voice service. This is the reason why Qualcomm and Ericsson are strongly against it.
  • Wimax is an open standard, which means there will be no or very little royalty (Qualcomm, the San Diego-based chipmaker, now charges patent royalties approaching 5% of the price of a 3G handset). This is one of the biggest advantages of Wimax.
  • Another key feature of Wimax is that it defines a Framework or APIs and leave implement details to individual company. It thus makes it possible to plug in those most recent progresses and keep itself up-to-date, and this also encourage competition to develop better system.

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