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WhyMax? The downfall of WiMax

Article

WiMax (Worldwide Interoperability for Microwave Access) is a wireless access technology standard devised by the IEEE as a successor to Wi-Fi.

Wi-Fi is a highly successful networking technology, but is most appropriate for indoor, short range deployments. The major success factor of Wi-Fi is interoperability – the Wi-Fi spectrum (2.4 GHz and 5 GHz) are fixed worldwide, and any Wi-Fi device can access Wi-Fi networks anywhere in the world.

WiMax is an attempt to replicate the success of Wi-Fi but instead allow carriers to use licensed frequency spectrum and deploy WiMax networks that are as ubiquitous as Wi-Fi.

Hence the WiMax technology largely follows Wi-Fi and instead of adding any radical innovation, simply attempts to do the same things as Wi-Fi just a in different frequency spectrum. Let's face it - there is no real range, capacity, or service improvement in WiMax. For fixed, outdoor deployments WiMax is fine. But those have been around for many years, and carriers need way more than that. Carriers need technologies that allow them to launch networks with least possible capital expense (less sites).

Unfortunately, WiMax was not designed as a carrier-class technology that real telecom carriers could use and benefit from. The spectral efficiency, range, true net capacity, and true mobility are missing and have very little difference from Wi-Fi. A majority of carriers and vendors have abandoned WiMax and are now waiting for newer, true telecom-grade technologies.

 

Same as Wi-Fi?

WiMax is based on the same OFDM physical layer as 802.11 Wi-Fi, with very little differences. OFDM and OFDMA are good at Non Line of Sight performance, but is weak at intercell interference avoidance. With Wi-Fi, spectrum is free (2.4 GHz, 5 GHz) and quite large (80 MHz and more), so re-using frequencies is less troublesome.

But in WiMax, the spectrum is licensed - and the licensee operators do not have huge amounts of spectrum. In some countries, operators have to live with as little as 10 MHz of spectrum. This severely limits the network efficiency, since the WiMAX physical layer is not adapted to such conditions.

The only advantage of WiMAX over WiFi is in fixed outdoor point to multipoint deployments, due to better MAC (Medum Access Control) techniques used by 802.16.

 

No Antenna Innovations

Antenna is the single weakest link in a wireless system, and Smart Antenna technology is the only way to improve antenna and thus overall system performance.

WiMax brings no antenna innovations either. Wi-Fi have implemented MIMO (Multiple In, Multiple Out) techniques, which are now popular in household access points and routers (802.11n). WiMax follows suit and implements almost the same MIMO techniques - without considering that MIMO works great indoors, but is totally powerless in outdoor carrier networks. It is actually even detrimental to the overall performance, and in most cases has to be switched off.

 

Vendor Experiences

Major telecom equipment vendors have ventured into WiMax, only to realize it's weaknesses. Some of them pulled out in time, some weren't as fortunate.


  • Cisco Systems: The networking equipment vendor tried to build WiMax solutions. The technology was too poor, and even such a powerhouse as Cisco had to abandon it. The products were scrapped in 2009.

  • Intel: Intel was one of the first backers and investors for WiMax. After a long struggle, the main R&D development center in Taiwan was closed in 2010.

  • Alcatel-Lucent: This major telecom equipment manufacturer attempted to build WiMax solutions. After large investments and major network failures, the products were discontinued in 2009.

  • Nortel Networks: After investing heavily into WiMax, Nortel found out that WiMax is not a mature technology with a future. However the heavy investments took its toll, and Nortel went bankrupt in 2010. WiMax failure played a major part in the downfall.

  • Nokia-Siemens: Fortunately for this prominent vendor, they quickly realized what WiMax is and is not. They famously called WiMax the “Wireless BetaMax” in reference to the failed video format, and did not attempt to enter this sector.

 


Upon closer look, there are absolutely no fundamental differences between Wi-Fi and WiMax and almost no advantages. Carriers do not need yet another Wi-Fi, they need truly powerful and innovative technologies that are designed according to carriers' needs.