The maximum posted speed limit on Interstate 95 is 65 miles per hour. Members of the Massachusetts, Rhode Island, and Connecticut State Police have pointed this out to me on several occasions. Unfortunately, the conversations did not occur during our state-wide radio system design reviews.
Why has our highway speed limit remained the same for over 40 years? The reason is highway technology hasn’t gotten out of first gear. The innovations that can increase the speed limit without sacrificing safety are still in the conceptual stage.
In the 40 years we’ve been transmitting data over RF, we’ve gone from 300 bits per second to 300 megabits per second. That’s increasing the speed limit one million times! What’s the secret of getting our data to travel so fast?
OFDM is the secret. OFDM isn’t a texting abbreviation like OMG or LOL so don’t ask your kids what it means. Orthogonal Frequency Division Multiplexing is the technology that takes LTE and 802.11n wireless broadband network traffic from zero to 60 in nanoseconds. OFDM splits your wireless broadband signal into multiple narrowband subcarriers and then reconstructs the data at the receiving end. Have you ever watched a motorcycle speed past while you’re sitting in bumper-to-bumper traffic? OFDM is like splitting your car into a virtual pack of Harley Davidson Sportsters that quickly weave between the lanes of crawling cars. The end result is your broadband traffic gets a significant increase in speed – and you don’t have to wear a helmet!
The OFDM-enhanced speed limit facilitates the transmission of clear, full-motion video on LTE and 802.11n wireless networks. This means improved situational awareness for public safety and public service personnel. The Department of Transportation will see real-time road conditions at their Traffic Management Center without having to dig up their highways to connect cameras and sensors. They may even see you roaring through traffic on your virtual Harley.
Now I wonder if I’ll get a ticket for going 300 mbps in a 200 mbps zone?