= Letibee Island =

[[PageOutline(2-4,Table of Contents,inline)]]

== Introduction ==

This document describes how to setup the SENSEI Letibee based island. 

== Objectives ==

The network at CEA-Leti provides information to an end-user located at a gateway or through the Sensei platform. These information are
* Nodes position
* Average value of a measure done at each node side (ie luminance or temperature)
* An estimated map of the measure done at each node side.

[[Image(cea_wsan.png, 40%, center)]]

Figure 1 : CEA WSAN + Gateway for Sensei

The WSAN activities do not use standardized communication protocols. Due to this constraint the communication with a node is not direct but through a virtual connection managed by a gateway (ie : a more powerful node included in the network).





= Datamanager =


[[Image(datamanager.png, 40%, center)]]


The datamanager is a standalone software which have the following objectives:

* Gather frames received on the usb port from the Letibee WSN
* Put data into database tables (rssi and position - see below)
* Remove older data if a time limit is specified


= Database =

The database is a MySQL database. The script below create the tables and the rows useful for the datamanager and the gateway.


{{{
CREATE DATABASE sensei;
USE sensei;

CREATE TABLE rssi (TxNodeId double);
ALTER TABLE rssi ADD (RxNodeId double);
ALTER TABLE rssi ADD (Rssi double);
ALTER TABLE rssi ADD (RelativeTime double);
ALTER TABLE rssi ADD (Time time);
ALTER TABLE rssi ADD (Date date);

CREATE TABLE position (NodeId double);
ALTER TABLE position ADD (PositionX double);
ALTER TABLE position ADD (PositionY double);
ALTER TABLE position ADD (Time time);
ALTER TABLE position ADD (Date date);

CREATE TABLE measTemperature (NodeId double);
ALTER TABLE measTemperature ADD (Temperature double);
ALTER TABLE measTemperature ADD (RelativeTime double);
ALTER TABLE measTemperature ADD (Time time);
ALTER TABLE measTemperature ADD (Date date);

CREATE TABLE measLuminance (NodeId double);
ALTER TABLE measLuminance ADD (Luminance double);
ALTER TABLE measLuminance ADD (RelativeTime double);
ALTER TABLE measLuminance ADD (Time time);
ALTER TABLE measLuminance ADD (Date date);

CREATE TABLE regmapOut (Type text);
ALTER TABLE regmapOut ADD (RefPositionX double);
ALTER TABLE regmapOut ADD (RefPositionY double);
ALTER TABLE regmapOut ADD (Value double);
ALTER TABLE regmapOut ADD (PositionX double);
ALTER TABLE regmapOut ADD (PositionY double);
ALTER TABLE regmapOut ADD (Time time);
ALTER TABLE regmapOut ADD (Date date)
}}}

= Octave algorithms =

Octave algorithms are used to compute rssi and position datas in order to generate more accurate positions datas and a regularized map. Different types of algorithm may be available. 


= Gateway = 

The Gateway task is to read on demand the information saved in DB tables and send these results by using the appropriate format to the end-user through the Sensei framework. 

[[Image(gateway.png, 40%, center)]]

The LetiBee plugin is based on a skeleton plugin and its HandleRequest method. Most of datas are reachable using GET methods, each making a request to the database to get the up-to-date datas. Published datas are listed below. 

= Published datas: =


The communication from the gateway to the end-user will be done using a text file. The Letibee WSAN is thinked like a geographic information database. This database contains nodes identities, positions (§Erreur : source de la référence non trouvée), measures and their histories (§Erreur : source de la référence non trouvée), estimate of others positions values using any kind of algorithms (§Erreur : source de la référence non trouvée). All these information will be send through the Sensei framework using the appropriate protocol and xml format.

== WSAN description ==

Resource description
	Sensors
		/letibee/nodes

This resource returns the number of nodes in the letibee network and their identities.

== Nodes position ==

Resource description
Sensors
/letibee/[nodeid]/[position]

Where position = positionX, positionY

This resource returns the position of the identified node

== Nodes measurements ==

Resource description
Sensors
/letibee/[nodeid]/[scalar_sensor_type]

With scalar_sensor_type= luminance, temperature

This resource returns the measured value of the sensor and time reference for the considered node.

== Regularized map ==

Resources description
Sensors
/letibee/regmap

This resource allows the user to choose between differents algorithms for computing the regmap, and the consensusStrength ; returns a VRML file (.wrl) (find a plugin here : http://cic.nist.gov/vrml/vbdetect.html)

	Parameters
		/letibee/mapdescription

This resource returns the name of the algorithm used to compute the last regmap.