Question on wireless technologies

Hi Vish,

The 2.4GHz frequency range is an unlicensed area used by all sorts of different radio technologies.  As you mention, Wifi, Zigbee, 802.15.4 (underlies Zigbee), and lots more.  There are other unlicensed areas in the radio spectrum.  You can find out more with your favourite search engine.

Have a look at the Open Energy Monitor project.  You'll find details about some wireless chips/modules they use.  Also have a look at the TI CC1101.  It's my personal favourite.  Nordic semiconductor nrf24l01 modules.

One final recommendation, PanStamp.  It is a Atmega or MSP430 based wireless radio and microcontroller system with an excellent protocol for sensor and actuator networks.  PanStamp supports web integration and interoperability with a variety of popular tools.  It's all open source, and the creator sells nice hardware modules too.

Good luck,

Lawrence

Lower frequencies penetrate walls better, so look for lower frequency radios. (433 MHz will penetrate better than 2.4 GHz)

To get through 6 walls will likely require more power than a typical unlicensed radio module will provide. Bluetooth Class 1 is rated to go 100 m. I have run it through 6 walls but you may still have trouble with 6 walls, depending on what they are made of.

You may need to resort to directional antennas, so choose radios that allow an external antenna to be substituted.

I noticed your tag as Internet of Things, If that is more relevant then WiFi will be your best bet.

Lower frequencies have a better chance of getting through walls but require longer antennas, so if you project doesn't matter in regards to size then lower frequencies are a good alternative. The major downside to lower frequencies though is data throughput is way lower than 2.4GHz.

At 200 Kbps you will be running close to the ceiling of 433MHz so your best bet would be 2.4GHz

There is also 315MHz, 868-915MHz, the higher the frequency the faster the data rate, as the bandwidth is higher at these frequencies

Malcolm

Hello Vishnu,

Are you using Arduinos by any chance?

For wireless transceivers, my favorite is the RFM69HW, followed by the nRF24L01...as long as you have the freedom to define your protocol.  If you simply want to have two Arduinos talking wirelessly to each other, these are the best and cheapest, with the most flexibility.  I recommend taking a look at the RFM69HW.  It's not as well known as the nRF24L01, but it's got much better range (over 700 feet through walls).  Both are capable of encryption and sleep, so they work well for battery powered Arduinos.

The RFM69HW is $4 each, the nRF24L01+ (high power version) is about $6.  The only disadvantage to the RFM69HW is that it's not 5V tolerant, but I've pretty much transitioned all my Arduinos to 3.3V.  Edit:  also wanted to add that RFM69HW is 915MHz, and nRF24L01+ is 2.4GHz.

I use them extensively in my budding home automation project.  I don't like zigbee or bluetooth because they're expensive...if you want lots of nodes, the cost adds up.  Plus they don't have as good a range.

Inexpensive & Flexible Home Automation / Wireless Sensors

The other option is Nordic NRF905 which can do 433, 868, 915 MHz

There are libraries around and are similar to the 2.4Ghz versions, although not quite as cheap.

Mark