If you thought Bluetooth and WiFi receivers were the only viable option for wireless transmission, check out the ONEmicro DECT speaker!
The ONEmicro speaker uses Digital Enhanced Cordless Telecommunications (DECT), which is the same technology used by traffic lights and wireless phone systems.
As ONEmicro uses the DECT standard, the ONEmicro speaker has lower power consumption than Wi-Fi and Bluetooth and has a dedicated 1.9GHz channel with no sharing of bandwidth so you get better sound stability than with Wi-Fi and Bluetooth.
The ONEmicro speaker comes with a USB dongle device which the ONEmicro speaker communicates with.
The way this works, you first connect the USB dongle to the audio source device and then press the button with the "plus/power on" symbol. This turns on the speaker and searches for the dongle (LED indicator blinks once). The "minus/power off" symbol turns off the unit.
Once paired/connected (LED indicator stays on), the speaker will do a voice prompt that says "connected to dongle, I'm on left or I'm on right". If you have two speakers, the voice prompt will say "I'm on left and I'm on right" which means the speakers automatically separate into left and right channels. If there is an interference in the channel, the LED indicator will do a short flash.The ONEmicro speaker also comes with two standard micro USB cables as well as a male to USB Female cable that allows you to connect the dongle to your smartphone to stream music directly to the ONEmicro speaker.

Once the speaker is on, you can get a report status by pressing and holding the "plus/power on" symbol. Pressing and holding the "minus/power off" symbol gives you a report on battery usage, sound profile (warm, natural or clarity), audio mode (HQ or ECO) and whether the speaker the left or right speaker is connected to audio dongle. As far as the speaker itself, the ONEmicro features a USB charging port, LED indicator, and two buttons  (volume up/power on and volume down/ power off) on the base of the speaker.