By Sriram V IyerI spoke about Wi-Fi won the battle on being the technology of choice for basic networking in laptops and later mobile devices too.
The fight was taken to the next level in WAN technologies. With the deployment of 4G technologies imminent, the field became very interesting.
To put simply, to create 4G technologies, we needed to have the data rates that were prevalent in WiFi (20-30 Mbps) but also have the mobility, that were the forte of existing cell phone technologies. One player’s strength was others’ weakness.
It was the question of if data communications based WiMAX (802.16e) would gain mobile capabilities and keep up its intrinsic strength of fast data rates, or if cellular technologies (like CDMA, WCDMA, etc) would get fast data rate capabilities retaining their mobility. Sounds like a thriller, isn’t it?
To be honest, mobile wireless broadband was created by technologies powered by WiMAX (IEEE 802.16e) which was launched in late 2005 in S. Korea (in a flavor called WiBro) – With this, close to 25 Mbps was initially available at the network, permitting video conferencing, HD video streaming etc. However, there were initial hiccups during handovers (when a mobile moves from one cell to another, the signaling is transferred from one cell to another) – Typical handovers initially were in tune of 120 – 150 milliseconds. (Not bad for data traffic, but bad for voice)
Despite being first in market, WiMAX did not do great, and will be relegated to background, for the reason similar to why WiFi won – Compatibility.
Considering 4G technologies, the two options were WiMAX and another was LTE (Long Term Evolution – Sorry if you expected something fancy :) ) – While LTE was delayed, it was an upgrade to existing networks, while WiMAX was a brand-new technology. The operators who had spent a lot of money in 3G, were apprehensive of sinking a lot of money in a brand new technology, while LTE was only a couple of years away, then.
WiMAX was a great technology – It offered mind-boggling speeds in a mobile environment, brought lot of technologies that were considered only lab-worthy out to real life. WiMAX brought very exciting technologies to mainstream:
- MIMO (Multiple Input, Multiple Output)– You might see a lot of ads saying – ‘Powered by MIMO’. These systems have transmitters and receivers with more than one antenna. I assure you that this is way more complex than sticking another antenna to your mobile :)
- Space-Time Frequency Coding (I’ll do well to skip explaining what is this, but to put it simply, it is a way of encoding data at the transmitter and decoding it at the receiver to boost overall data rates. If my mailbox gets flooded with requests on explaining this, I’ll certainly do it :) )
- Downlink Channel Reporting – In Communication systems, only a receiver can measure the nature of the wireless channel in which data is transmitted. This is measured and sent back to the network for tuning the amount of data or data rates sent from network to the receiver. To simply put, if the mobile is in a very noisy area, send data at lower data rates, else send it at much higher data rates
- Beam Forming – This is definitely Star-Trek stuff. It is normal for some of us to go around the office or the road, asking ‘Is it clear now?’ while talking on the phone. While you can certainly do it, your house cannot move around. So, if you are one of the lucky people in the cell edge where the signal is permanently low, you’ll be blessed with a constant low signal and hence low data rates (See #3), though your provider will not reduce your subscription rates. To provide good signal to these areas, technologies like beam forming are used. In this an array of antennas produce signals (waves) that constructively interfere to spacially provide excellent signal strength to the subscriber in bad coverage area. (yes, I wrote that sentence!)
While WiMAX proved these and many more, LTE smartly learnt from these experiences and incorporated a good part of these, removed some, and is ready for prime.
WiMAX, is an example of technology that despite doing a lot of things right, failed, despite being the first in the market. It is a classic example of why things can fail despite a working solution, and being first in market.
But, I can certainly say one thing for sure – I loved working in both WiFi and WiMAX, and certainly enjoy contributing to the LTE ecosystem!