Category Archives: Cellular

What does FHSS have to do with the $10 bill?

10Heddy

 

The US Treasury department thinks that we need a woman on the $10 bill.  I don’t know why they want to take Old Hamilton off because he was for the central bank in the first place, but this is a tech blog not a political one.

So I nominate Hedley Lamarr! Sorry that’s Hedy Lamarr…

Hedy Lamarr was born in eastern Europe and fled to America during the rise of the Nazis and Facists.  She became a leading woman in Hollywood and is known as one of Hollywood’s most beautiful.  However few know that her intellect rivalled her beauty.

With the help of her Hollywood composer neighbor, George Antheil, she developed Spread Spectrum and Frequency Hopping technologies to thwart the jamming of Allied radio communications by the Axis.  Wifi, CDMA, and Bluetooth are all based on the work he initiated.

Differences between FHSS and DHSS:

  • DHSS has higher throughput than FHSS (as much as ten times)
  • FHSS resists jamming nlike DHSS
  • DHSS is much more efficient in an outdoor environment.
  • FHSS does well indoors as it reacts more efficiently multipath
  • FHSS is more suceptible to narrowband noise than DHSS
  • DHSS combats microwave oven interference  better than FHSS
  • The synchronization of FHSS is a fraction of that used by DHSS
  • DHSS suffers more from the challenges of Near-Far than FHSS

fhss

 

 

Using WiFi to overcome a weak cellular coverage

credit: Ankit Tuteja
credit: Ankit Tuteja

So we have all had issues with our cell phone.  So says Ankit Tuteja in an article which gives some ideas on boosting performance which you can find here:       http://www.ibnlive.com/news/tech/no-signal-6-simple-tricks-to-help-you-get-better-mobile-connectivity-1000301.html   But wait “…you are  WiFi Superman, not SmartPhone Superman” you say.  This is true but there is much overlap in the RF/Wireless world not to mention within devices like SmartPhones.  This leads me to my next point.  If you have a bad cell signal for voice or data you can sometimes fix this by establishing a good WiFi connection.

In addition to Mr. Tuteja’s tips on boosting your cell phones performanceI recommend the following workarounds:

  1. For voice Issues use Skype, Google Voice, or others listed here:  http://www.makeuseof.com/tag/fed-up-with-skype-here-are-6-of-the-best-free-alternatives/
  2. For Data Issues tether your device to a friend who has stronger coverage from a different provider.  To find out more about tethering / mobile hotspots check out this article:  http://www.pcadvisor.co.uk/how-to/mobile-phone/how-use-your-smartphone-as-wi-fi-hotspot-ios-android-windows-phone-3441165/
  3. To help your signal for both voice and data use BlueTooth or even better an ear bud as it will reduce attenuation of the device while reducing your brain’s exposure to LTE, WiFi, and BlueTooth (if you choose the ear bud option)

I hope between the info in this blog and in Ankit’s article your mobile experience will be a little better each day!