Image

Whatever Happened to WiMAX?

April 2, 2015
WiMAX’s original target was apparently wireless Internet access, an alternative to cable TV and DSL, especially in rural areas where good Internet access was not typically available.
Image courtesy of Thinkstock.

Back in the early 2000s, the WiMAX Forum developed a new wireless technology known as WiMAX —short for Worldwide Interoperability for Microwave Access.  The new technology was standardized by the IEEE as 802.16.  And through the mid-2000s it was continuously updated.  The WiMAX Forum promoted the technology and established a certification program for products to ensure interoperability. WiMAX got lots of attention and many thought it would be the next Wi-Fi.

WiMAX’s original target was apparently wireless Internet access, an alternative to cable TV and DSL, especially in rural areas where good Internet access was not typically available.  It was also used for microwave backhaul.  In addition, it was considered a prime candidate for 4G cellular beyond CDMA and GSM/HSPA.  But then along came Long Term Evolution (LTE).  While WiMAX did make it in the 4G cell phone business thanks to Sprint and some carriers outside the U.S., most other and all the major carriers adopted LTE.  Eventually even Sprint has been changing its networks over to LTE and phasing out its WiMAX phone systems.  The last will go off line sometime this year.  Basically what happened to WiMAX is LTE.

Yet, WiMAX is still around.  It is still widely used for wireless Internet access especially outside the U.S.  There are hundreds of WiMAX installations worldwide, but not so many in the U.S.  One main wireless Internet Service Provider (WISP) is Clearwire or CLEAR, a division of Sprint that still widely deploys WiMAX throughout the U.S.

In case you do not know or just forgot, WiMAX is an OFDM technology. It uses 256 subcarriers and can be adjusted to use bandwidths of 1.25, 5, 10, or 20 MHz.  The original standard was for the 10 to 66 GHz range, but later versions added the 2 to 11 GHz range. Most WiMAX installations seem to use the 2.3 to 2.5 and 3.5 GHz bands.  Backhaul uses the higher frequencies.  Most WiMAX services use time division duplex (TDD) that does not require the dual spectrum assignments of frequency division duplex (FDD) as used in most LTE installations.

As for data rate, speeds up to 1 Gb/s are possible with the latest versions with high-count MIMO.  A typically quoted spec is up to 70 Mb/s at 50 km. Not bad. Most WISPs deliver speeds in the 1 to 5 Mb/s even in non-line of sight instances up to several km.

I contacted the WiMAX Forum with some questions and they responded with a comprehensive Q&A.  Take a look at this detailed update here.  Also check out the WiMAX Forum for the latest word. 

WiMAX is alive and well, but currently living in the shadow of LTE.  It is a great wireless technology that has found its own niche.  It could really become an alternative technology for the Internet of Things (IoT) as that movement comes into its own.  Anyway, it is worth considering.  At least its fate is positive unlike another OFDM-based wireless technology, IEEE 802.22.  But that’s another story.

About the Author

Lou Frenzel | Technical Contributing Editor

Lou Frenzel is the Communications Technology Editor for Electronic Design Magazine where he writes articles, columns, blogs, technology reports, and online material on the wireless, communications and networking sectors. Lou has been with the magazine since 2005 and is also editor for Mobile Dev & Design online magazine.

Formerly, Lou was professor and department head at Austin Community College where he taught electronics for 5 years and occasionally teaches an Adjunct Professor. Lou has 25+ years experience in the electronics industry. He held VP positions at Heathkit and McGraw Hill. He holds a bachelor’s degree from the University of Houston and a master’s degree from the University of Maryland. He is author of 20 books on computer and electronic subjects.

Lou Frenzel was born in Galveston, Texas and currently lives with his wife Joan in Austin, Texas. He is a long-time amateur radio operator (W5LEF).

Sponsored Recommendations

Wideband Peak & Average Power Sensor with 80 Msps Sample Rate

Aug. 16, 2024
Mini-Circuits’ PWR-18PWHS-RC power sensor operates from 0.05 to 18 GHz at a sample rate of 80 Msps and with an industry-leading minimum measurement range of -40 dBm in peak mode...

Turnkey Solid State Energy Source

Aug. 16, 2024
Featuring 59 dB of gain and output power from 2 to 750W, the RFS-G90G93750X+ is a robust, turnkey RF energy source for ISM applications in the 915 MHz band. This design incorporates...

90 GHz Coax. Adapters for Your High-Frequency Connections

Aug. 16, 2024
Mini-Circuits’ expanded line of coaxial adapters now includes the 10x-135x series of 1.0 mm to 1.35 mm models with all combinations of connector genders. Ultra-wideband performance...

Ultra-Low Phase Noise MMIC Amplifier, 6 to 18 GHz

July 12, 2024
Mini-Circuits’ LVA-6183PN+ is a wideband, ultra-low phase noise MMIC amplifier perfect for use with low noise signal sources and in sensitive transceiver chains. This model operates...