Hi all,
Do you know what UWB means? What is that for? Have you ever heard about it?
If not, we'll study this new and quite nice communication protocol together. If you've already heard about it, it's not that bad to review some concepts, right?
In this post I'll introduce UWB protocol and on next one, talk a bit about Linux-UWB project maintained by Iñaky Perez-Gonzales from Intel.
Overview
UWB stands for Ultra Wide Band. It's a communication protocol that is to serve as a low-level layer for other protocols to build on top of it. Something like IP is for TCP.
Currently, there are a few users for this low-level layer; namely: WUSB and TCP/IP. Bluetooth and FireWire/1394 are also looking forward to build on top of UWB.
This protocol uses a really wide radio frequency band (from 3 to 10 GHz) transmitting at a max of ~-40dB (not yet really defined, can change). This band is divided in several channels, each channel is completely independent of each other. They actually look like different busses.
Each UWB device has a MAC and a device address and send periodic beacons to advertise and pass info about themselves.
Diving in UWB
UWB is high speed, short range (up to 10 meters or so) radio technology intended to replace most of the data cables in all kinds of PAN-like interconnects. It was defined by the WiMedia consortium. Its standard is ECMA-368 and now is on IEEE for further standardization.
This technology provides all the blocks needed by higher level protocols to use it - i.e. build on top of it - without any central infrastructure. Such blocks are: delivery of payloads, neighborhood and bandwidth management, encryption, broadcast, multicast, unicast, etc.
It's designed for being low-power with good facilities for QoS and streaming and providing strog cryptography on the transport to compensate the open medium (aka, air).
Below a picture of UWB spectrum usage:
This protocol operates over the unlicensed 3.1 to 10.6 GHz band, transferring at data rates up to 480Mbps. Time is divided in superframes, composed of 256 Media Allocation Slots (MAS), of 256us each.
That's all for now. We're gonna study a bit more about it in later posts. It's already too big.
See y'all